CA1210971A - Axial flow valve - Google Patents
Axial flow valveInfo
- Publication number
- CA1210971A CA1210971A CA000455598A CA455598A CA1210971A CA 1210971 A CA1210971 A CA 1210971A CA 000455598 A CA000455598 A CA 000455598A CA 455598 A CA455598 A CA 455598A CA 1210971 A CA1210971 A CA 1210971A
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- CA
- Canada
- Prior art keywords
- rotor
- casing
- instrument
- end plate
- wall
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
AXIAL FLOW VALVE
ABSTRACT
A rotary valve for selectively inserting and removing a slide loop from the sound path of a musical instrument is disclosed. The valve includes a rotor having an outer surface portion that is substantially conical and also includes a casing with a substantially conical inner surface portion that receives the outer surface portion of the rotor. Two sound passages entending through the rotor are no more than slightly curved. These passages align axially with the instrument's lead pipe, main bore, and slide loop ends so that a minimum or undesired hamonics are added to the tone of the instrument due to presence of the valve in the sound path.
ABSTRACT
A rotary valve for selectively inserting and removing a slide loop from the sound path of a musical instrument is disclosed. The valve includes a rotor having an outer surface portion that is substantially conical and also includes a casing with a substantially conical inner surface portion that receives the outer surface portion of the rotor. Two sound passages entending through the rotor are no more than slightly curved. These passages align axially with the instrument's lead pipe, main bore, and slide loop ends so that a minimum or undesired hamonics are added to the tone of the instrument due to presence of the valve in the sound path.
Description
~JP/jlb ~ 1780~ 24915 AXIAL FLO~ VALV~
BRIEF SU~ARY OF THE INVENTION
This invention relates to a rotary fluid flow switch and more specifically to a rotary air valve of a musical instrument.
Rotary valves are highly regarded for use in musical instruments due to their quick action and relative simplicity of structure as compared to piston ~ype valves. Some prior rotary valves are compact and lightweight, but suffer from the disaavantage that they add overtones to the sound of the instrument when played.
These overtones are produced either inside the valve rotor or at the junction of the valve rotor with the instrument tubing, wherever there is a sharp bend or substantial variation in cross-sectional shape of the air passage.
When sound waves traveling through an instrument's sound passage are required to make sharp turns or pass through regions of varying cross-sectional shape, certain por r ions of the waves ref~lect off the inside wall of the passageO
Such a partial reflection reduces the energy of the fundamental wave and produces an undesirable overtone.
The present invention is a valve which adds few unwanted harmonics to a musical instrument's tone and weighs less than any prior valve of comparable acoustic qualityO The lead pipe and main bore of the instrument RJP/jlb ~ L780~ 24'~15 align axially with the passages of the valve rotor so that the sound waves enter, pass through~ and leave the valve ~ hout substantially char~ging direction or being deflected off the passage walls. ~uch a valve can be S constructed with a rotor having only ~wo passages, ~hich extend straight throuyh the rotor. Alternatively, one or both of such passages may be slightly curved.
The rotor has an outer surface portion tha~ is tapered, preferably generally conical. This rotor is received by a casing having a flared inner surface portion that conforms in shape to the outer sur~ace portion of the rotor. The tapered and flared su!face portions engage each other such that the rotor is maintained in propec axial alignment during its rotation. Because the rotor rotates on a conical surface portion, the entire vaLve can fit within a casing that is generally conical in shape and has but a single casing end plate. Such a valve weights less and occupies less volume than a cylindrical rotary valve of the same diameter. Because the entire valve can be tapered, at least one of the sound passageways can be very short and yet extend substantially stralght through the rotor. The valve thus can be used to mount very short slide loops, with no reduction in sound yuality.
A valve according to the present invention can have as few as three primary elements: (1) a casing having a flared inner surface; (2) a tapered rotor that fits in the casing and can be removed for cleaning; and ~3) some means to releasably re~ain the rotor in the casing.
3Q In one embodiment, the casing is partially closea at its base by an end wall; and the rotor is axially-truncated so that it can be removed through the uncovered portion of the casing base. Another embodiment includes a casing that is completely open at its base, the 3~ rotor being secured by an end plate detachably mounted over the opening b~ a threaded retainer rin~.
73~
The present invention provides a rotary valve for a musical wind instrument having a slide loop, an instrument pipe wi-th a mouthpiece at one end and an instrument pipe termina-ting in an instrument bell.
The valve comprises a casing and a substantially frusto-conical rotor rotatable in the casing. The casing includes a substantially frustoconical casing wall having a base and a narrowed end, the wall -tapering directly toward and defining an ax1al frustrum aperture at the narrowed end and a casing wall aperture at a location between the base and the narrowed end, and a -transverse casing end plate at the base of the wall, the end plate defining primary and secondary end plate apertures. The rotor has a primary rotor passage which connects the primary end plate aperture to the frustrum aperture when the rotor is in a first position and which connects the secondary end plate aperture with the frustrum aperture when the rotor is rotated to a second position. The rotor also has a secondary rotor passage which connects the primary end plate aperture to the wall aperture when the rotor is in the second position.
The primary end plate aperture connects to one of the instrument pipes. The frustrum aperture connects to the other of the instrument pipes, the secondary end plate aperture connects to one end of the loop, and the wall aperture connects to the other end of the loop.
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RJP/jlb ~ 178~D 24915 It is an object of the present inventi~n to provide a musical instrument rotary valve which is lightweight, of simple design, requires a minimum of parts, is inexpensive and easy to construct.
A further object is to provide such a valve with a rotor that can be easily removed for cleaning without the use of tools or with one simple tool at most~
Also, an object of the invention is to improve the acoustic performance of all valved brass wind instruments, such as trumpets, alto horns, French horns, trombones, baritones and tubas, by providirlg a valve which does not ha~e the abruptly angled sound passages of most prior rotary and piston valves.
An additional object of this invention is therefore to provide a rotary valve having passages which extend in a straight or substantially straight path therethrough and are of a uniform circular cross section throughout their entire length.
Another ob~ect is to provide a rotary valve in which the instrument's lead pipe and main bore align axially with the passages through the valve's rotor.
Yet another object is to provide certain rotary valves where the lead pipe and main bore are in axial alighnment with each other at the locations where they attach to the valve so that when the rotor is in one operating position there is a straight passage from the lead pipe to the main bore.
It is also an object to provide a rotary valve having inlet and outlet ports configured such that multiple valves can be located in close proximity with a substantially straight sound path extending from ~he lead pipe, through all of the valves, to the main bore.
A further object is to provide a rotary valve having a rotor which requires only two passages extending 3S axlally therethrough.
A still further object of the invention is to provide a r~tary valve having a rotor passage which, at ~.Z~ 7~
IWP/jlb ~ 1780~ 24915 one end, is coaxial to the axis of rotor rota~ion.
Other objects, advanl:ages and features of this invention will become apparent to those skilled in ~he art upon reading the following specification.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
Fig. 1 is a side elevation of a B-flat trombone incorporating a first valve according to the present invention;
Fig. 2 is an enlarged, isometric, exploded view of the valve shown in Fig. l;
Fiy. 3 is a plan view on a further enlarged scale of the valve shown in Figs. 1 and 2;
Fig. 4 i5 a sectional view taken along line 4-4 Of Fig. 3;
Fig. 5 is a sectional view taken along line 5-5 of Fig. 4, the view including a vertical sectional view of a rotor in a first or direct flow position;
Fig. 6 is a sectional view taken along line 6-6 of Fig. 5;
Fig. 7 is a vertical, sectional view of the rotor shown in Fig. 5, the rotor being shown as rotated ~o a seSond or diverted flow position;
Fig. 8 is an isometric schematic view showing the flowpath of a valve according to the present invention with a rotor in a first or direct flow position;
Fig. 9 is an isometric schematic view showing the 10wpath of the valve of Fig. 8 with the rotor in a second or diverted flow position;
3~ Fig. 10 is a side elevation of a B-flat trol~lbone incorporating a second valve according to the presen~
invention, Fig. 11 is an enlarged, isometric, exploded view of the valve shown in Fig. 10;
Fig. 12 is a fragmentary plan view of a musical wind instrument incorporating three of the valves shown in Fig. 10 in series;
3~
RJP/~lb B 1780D 24gl5 Fig. 13 is a fragmentary plc~n view of a musical wind instrument incorporating third valve according to the present invention for simultaneously engaging two slide 1 oo~s;
5Fig. 14 is a partial sectional view taken along line 14-14 of Fig. 13;
Fig~ 15 is a sectional view taken along line 15-15 of Fig. 13;
Fig. 16 is a sectional view of the valve rotor 10 shown in Fig~ 15 taken along lines 16-16 of Fig. 15, the view being a ver~ical sectional view of the rotor in a first or direct flow position; and Fig. 17 is a sectional view of the valve rotor shown in ~ig. 15 taken along lines 17-17 of Fig. 15, the 15 view being a vertical sectional view of the rotor in a second or diverted flow position.
DETAILED DESCRIPTION
Rotary valves for selectively inserting and removing a slide loop from the sound path of a musical instrument are shown in U.S. Patent No. 4,112,806 issued September 12, 1378, U~S. Patent No. 4,~13,37], issued July 22, 1980, and U.S. Patent No. 4,299,15Ç issued November 10, 1981. Each such valve inclu~es a rotor having at least two sound passages extending therethrough, whi~h are no more than slightly curved. The passages align axially with the instrument's lead pipe, main bore, and slide loop ends so that a ~inimum of undesired harmonics are added to the tone of the instrument due to presence of the valve in the sound path. Each of these previous valves are simple 33 in construction and have a superior sound path.
Valves according to the present invention have the aforesaid favorable features and new features which provide benefits o a different nature. A valve according to the present invention has a rotor with an outer surface 97~
I~JL~/jlb u 17~1) 24(~15 which provides a contact face that is detined in a generaliy conical surface. The face may be defined in any tapered surface that is circular in ri~ht cross sectlon;
but a tr~le cone is preferred~ The rotor is contained within a casiny which has an inner surface portion with a contact surface that conforms in shape to the same generally conical surface as does the rotor surface. Due to the conical shape of the contact surfaces, the rotor is self-centering within the casing ana will have a low mass and thus a low inertia. The lightweight rotor responds to an instrumentalists finger movements more quickly than prior rotors of greater mass.
Because they can be constructed using a minimum number of parts, valves according to the present invention can be very low in total weight. One preferred valve has only three basic separable parts, a casing, a door plate, and a rotor, as shown in Figs~ 1-7 of the drawillg. The valve shown in Figs. 10~12 has only a casiny, a door plate, a rotor and a retaining ring. Despite the simplicity and low weight of such preferred valves, each has a rotor that is easily removable for cleaning.
As illustrated in ~igs. 1-7, a first valve according to the present invention has a cacing 10 which includes a substantially frustoconical casing wall 12 having a base end and a narrowed end, a sleeve 16 secured on the narrowed end, and a transverse casing end plate 14 fixed on the base end of the casing. The end plate 14 has flat surfaces positioned perpendicular to a longitudinal axis "Al" of the casing and defines two casing end plate apertures. One of the end plate apertures is a primary casing end plate aperture 24 having an axis which is parallel to but displaced from the axis "Al". The other is a secondary casing end plate aperture 26 the center of which is displaced an equal distance away from the longitudinal axis "Al" as is the cen~er of the primary casing end plate aperture 24.
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I~JP/jlb ~ 17~0D 24915 The end plate 14 of the casing shown ln Figs.
1-6, only partially closes the base end of the casing. As best seen in Fig. 2, the end plate 14 leaves an o~ening 27 into the casing through which the rotox may be removed for inspection and cleaningO In order to allow suflicient Loom for the passage of the rotor, it is preferred that the end plate 14 cover an area contained entirely wlthin two adjacent quadrants of the base end of the casing. A
door plate 28 mounts detachably alongside the end plate 14 over the opening 27 at the one end of the casing wall 12 and is held in place by screws 29~ The door plate 28 includes a circular shaft aperture 30 which is positioned coaxially to the longitudinal axis "Al" when the aoor plate i5 mounted on the casing ~all 12. The sleeve 16 defines a circular, axial casing frustrum aperture 32 coaxially aligned with the iongitudinal axis "Al" of the casing wall 12. The casing wall 12 defines a casing wall aperture 34 at a location between the casing ends.
The casing wall 12 includes a right frustoconical portion 35 and a cylindrical portion 36 whlch extends from the base of the frustoconical portion 35 to a circular casing outer end 37 which is the base end of the casiny wall 12. The frustoconical portion 35 and cylindrical portion 36 have a common axis which coincides with the axis "Al".
Inside the casing are two opposed interior contact faces. The interior of the casing wall 12 provides one interior contact face which is an area defined in a tapered surface of circular cross section.
In the illustrated embodiment, the frustoconical portlon 35 has a flared, substantially conical inner surface 3~
that provides the one contact face and which serves as a coaxial, concave seat for the rotor. The other contact face is the inner surface 3~ of the casing end plate 14.
A substantially frustoconical rotor indicated generally at 40, is located insiae tne casing. At one en~
of the rotor 40 is a rotor end plate 42 having a curved XJP/jlb B 1780D 24915 l~lU971 edge portion 43 in a ra~ius slightly less than the greatest inside radius of the casing wall 12. This rotor end plate lS positioned with one of its flat surfaces adjacent inner surface 39 of the casing end plate 14. The rotor end plate 42 includes a primary rotor end plate aperture 44 adapted to register alternaLely with the primary casiny end pLate aperture 24 when the rotor is in a first position and with the secondary casing end plate aperture 26 when Ae rotor is in a second position. The rotor end plate 42 also includes a secondary-rotor end plate aperture 46 which is positioned to reg1ster with the primary casing end plate aperture 24 when the rotor is in the second position.
Extending from the rotor end plate 42 to the other end of the rotor is a rotor wall 50 which defines a rotor frustrum aperture 52 at the end opposite the rotor end plate 42. The wall has a tapered, arcuate outer surface~ In the illustrated embodiment, the rotor wall 5 is substantially frustoconical. ~ rotor wall aperture 54 is defined in the wall 50 at a location between the rotor ends.
The illustrated casing wall 12 has an inner surface at least a portion of whiGn has the shape of a circular cone ~ith the same angle of generation as that of the conically-shaped portion of ~he surface of the rotor wall 50. The conical surface portion oE the wall 50 seats against the conical surface portion of the casing wall 12 so that the rotor frustrum aperture 52 remains in alignment with the casing frustrum aperture 32 at all times. The rotor wall aperture 54 registers with the casing wall aperture 34 only when the rotor 40 is in the second position. When the rotor is in tne second position, each of the rotor apertures registers with a casing aperture. The rotor aper~ures and the casing apertures preferably correspond exactly in size and shape to one another to minimize the resistance to soundhaves passing between the casing and rotor.
97~
~WP~jlb B 1780D 24915 Rotor tubes provide passages for air traveling - through the rotor 40. A rigid primary rotor tube 60 extends throuyh the rotor and connects the primary rotor end plate aperture 44 with the rotor frustrum aperture 52. Optionally, a cylindric~1 extension (not shown) of the primary rotor tube 60 could extend into the casing axial aperture 32 so that the extension would be journaled within the aperture 32 and the sleeve 16.
A rigid secondary rotor tube 61 extends through the rotor and connects the secondary rotor end plate aperture 46 to the rotor wall aperture 54. The axis of this secondary rotor tube 61 is substantially perpendicular to the rotor end plate 42 where they join and is coaxial with the secondary rotor end plate aperture 46~ Where the secondary rotor tube 61 joins the rotor wall aperture 54, they are coaxial. At this location, the secondary ro~or tube 61 of the illustrated embodiment extends radially outwardly at an acute angle to the axis "Al" as best seen in FigO 7. Although hollow tubes provide the sound passayes of the preferred rotor, other constructions could be used. For instance, a solid rotor having passages extending therethrough, would be suitable but not preferred due to its greater mass.
The iliustrated rotor is specifically shaped for use in the casing previously described. The rotor wall 50 includes a right frustoconical portion 62 having a base end and a narrowed end, and a right cylindricaL portion 63 which extends from the base of the frustoconical portion 62. The rotor end plate 42 is secured to the outer end of the cylindrical portion 63. The frustoconical portion 62 and cylindrical portiosl 63 have a common axis which coincides with the axis "Al" when the rotor is installed inside the casing.
To lower rotor size and weight and allow for easy removal, the rotor wall 50 is axially-trunca~ed so that it has an axially-extending edge 64. An axially extending rotor side wall 65 is mouslted on the rotor wall 50 at the 1 ;~.L~971 RJP/jlb B 178~D 24915 edge 64 to enclose the rotor. A transverse section OL the rotor, taken through the rotor side wall 65, woul~ show the outer surface of the rotor as a ma~or arc ~ormed by the rotor wall 50 and a secant formed by the side wall 65.
The rotor has two o~posed exterior contact faces which face the interior contact faces of the casing. The outside of the rotor wall 50 provides one exterior contact face which is an area defined in a tapered surface of circular cross section that conforms to the surface whlch defines the one interior contact face of the casing. In the illustrated rotor, the substantiaLly conical outer surface 67 of the rrustoconical portion 62 provides a contact face that mates with the inner surface 38 of the casing. Specifically, the tapered outer surface 67 seats in the rotor seat formed by inner surface 38 so that th~
rotor is centered for rotation relative to the casing.
Proper rotor alignment is best achieved if at least a portion of each tapered contact face is a major arc in cross section. Preferably a portion of at least one of said contact faces is a complete circle in cross section at the narrowed ends of the casing and rotor as shown in Fig. 6. The other rotor contact face is provided by the outer surface 68 of the rotor end wall 42 and is positioned to face the inner surface 39 of the casing end wall 14.
A shaft 70, extending froln the outer side of the rotor end plate 42, is coaxial to the longitudinal axis "Al". The shaft 70 extends through tne sha~t aperture 30 so that the rotor can be rotated about the axis "Al"
by rotating the shaft 70.
The best tone quality is achieved if sound waves traveling through the valves of the musical instrumen~
encounter a minimum amount of resistance. By mounting the instrument tubes so that their axes register with the tube axes at the points where the tubes are mounted on the casing, a minimum amount of resistance is encountered during the transfer of sound waves between the instrument 7~L
I~JP/jlb ~ 17~ 24915 tubes an~ the rotor passayes. Resistance inside the rotor passages is low because the tubes 60, 61 are substantially straight and of a uniform, circular cross section throughout their entire length.
The primary rotor tube 60 is shaped as a slight S-curve and has end portions positioned to be substantially parallel to the axis "Al". An alternative to the S-shaped primary rotor tube 60 is a straight tube (not shown) extending diagonally between tne primary rotor end plate aperture 44 and the rotor frustrum aperture 52.
Such a diagonal tube would provide a substantially straight soundpath; but the ends of such a straight diagonal primary rotor tube would not align axially with the illustrated instrument tubes so there would be some resistance to the transfer of sound waves between tne primary rotor passage and the instrument tubes.
The secondary rotor tube 61 curves gently as it e~tends between the secondary rotor end plate aperture 46 and rotor wall aperture 54. It is desirable to maximlze the radius of curvature to minimize resistance. Because it extends tnrough a conically shaped portion o~ rotor wall 50, the tube 61 can have a large radius of curvature or even be straight (not shown)~ The conical shape of the valve illustrated is also advantageous because, at a given tube size, such a valve occu~ies less space ana weighs less than any other valve having comparably straight sound passages.
Such valves according to the present invention are well suited for use in compact instruments and instruments requiring short sllde loops. The distance between the primary rotor end plate aperture 44 and rotor wall aperture 54 is so little that even the shortest slide loop can be positioned with it's ends in registry with those apertures.
Instrument tubes are mounted to the casing so that they connect with the casing apertures. Preferably the tubes and apertures are in axial alignment so that a l~P/jlb ~ 1780D ~915 ~ 9~
minimum amount of resistance is encountered during the transfer of sound waves between the instrument tubes and the rotor passages. The drawing figures show the first valve according to the present invention connected with tubes which cGrrespond to the tubes of a musical instrument. A lead pipe 74 and main bore 76 connect to opposite ends of the casing. The lead pipe 74 exten~s from the mouthpiece of the instrument and is connected to the primary casing end plate a~erture 24 which is located at a first of the opposite ends of the illustrated casing. The main bore 76 of the instrument connects to the casing frustrum aperture 32 which is located at a second of the opposite ends ~f the illustrated casingO A
slide loop 77 has opposite ends 7~, 80 which connect to the casing wall aperture 34 and the secondary casing end plate aperture 26 which is at one of the opposite ends, in this instance the first of such ends.
Fig. 1 depicts a valve according to the present invention incorporated in a musical instrument. More specifically, Fig. 1 shows a B-flat trombone which includes a single slide loop 77. By rotating the valve, the slide loop 77 may be added to the sound path so that the fundamental pitch of the trombone is lowered to the key of E-flat. The trombone has a mouthpiece 38 and a slide 90 which are portions of the lead pipe 74. The lead pipe connects to the primary casing end plate aperture 24 of the valve. One end 78 of the slide loop 77 is connected to the casing wall aperture 34. The other end 80 is connected to the secondary casing end plate aperture 26. The main bore 76 is connected to the casing frustrum aperture 32.
Means are provided on the instrument for r~tating the valve shat and rotor. Such rotating means can be of a common variety, as shown in Fig. 1, that em~loys a finger actuated key 92 rotatably mounted to a brace of the instrument and mechanically connected to the shaft 70 in such a manner that movement of the key causes rotation of ~P/jl~ ~ 17~0~ 2~915 ~ 97~
the shaft. Fig. 2 shows an arranyement where a crank ~4 - connects to the shaft and has a ball 96 which forms a part of a ball joint ~ith a linkage (not shown) which connects with the finger actuated key. One or more stops 98 may be provided to limit movement of the crank 94 and thereby assure positive alignment between rotor apertures and casing apertures.
When the instrumentalist moves the key 92, the rotor rotates about the longitudinal axis "Al" between l~ the positions illustrated in Figs. 8 and 9 wherein the rotor 40 appears in broken lines. Fig. 8 shows the rotor in the normal flow or first position. In this position, the primary rotor tube 60 connects the lead pipe 74 directly to the main bore 76.
By depressing the key 92, the rotor is rotated about the axis "Al" to the second or diverted flow position shown in Fig. 9; the secondary rotor tube 61 connects the lead pipe 74 with one end 78 of the slice loop; and the primary rotor tube 60 connects the other end 80 of the slide loop with the main bore 76. Thus, when the valve is in the first position, the sound waves can travel directly between the lead pipe 74 and the main bore 76. When the valve is in the second position, sound waves must pass through the slide loop 77 when traveling between the lead pipe 74 and the main bore 76.
The rotor may be removed for inspection and cleaning by removing the scre~s 29 and disconnecting the crank 94 from the shaft 70. When this is done, the aoor plate 28 can be removed to release the shaft 70. Using the fingers, the shaft is rotated until the rotor ena plate 42 aligns with the opening 27 through the base of the rotor casing whereupon the rotor can be pulled out through the opening.
To reinstall the rotor, tne procedure is reversed. The rotor is held in the position shown by broken lines in Fig. 2, and pushed through the openlng to the point where the conical surfaces engage. Once I~J~jL~ 13 17~u 2~15 ~ 97~
inserted, the rotor is finger-rotated to its operating ~osition after which the door plate 28, screws 29, and crank 94 are returned to their places.
FigsO 10-12 illustrate a second valve according to the presen~ invention ~hich is closely related to the valve shown in Fiys~ 1-7~ Each feature of the second valve that is common to a feature of the first valve bears the same reference numeral incremented by one hundred.
The second valve has a casing 110 with a substantially frustoconical wall 112 with a longitudinal axis "A2".
An end plate 120 having flat surfaces positioned - perpendicular to the axis "A2" defines the two casing end plate apertures 124, 126, displaced an equal distance away from the lonyitudinal axis "A2". The casing shown in Figs. 10-12 has an end plate 1~0 which closes the base end of the casing. A retainer rin~ 121 secu~es the end plate 120 to the casing wall 112~ The ring has interior threads 122 which mate with exterior threaas 123 on the casing wall 112. The end plate 120 includes a circular shaft aperture 130 which is positioned coaxiaLly to the longitudinal axis "A2" when the end plate is moun~ed on the casing wall 112.
A sleeve 116 defines a circular, axial casing frustrum aperture (not shown) that is coaxially aligned with the longitudinal axis "A2" of the casing wall 112.
Unlike other embodiments, however~ the sleeve 116 has an axis 11~311 at an acute angle to the axis of rotation "A2". As seen in Figs. 11 and 12, the lead pipe 174 and main bore 176 are also coaxial to axis "A3", as is the primary rotor tube 160 when the valve is in the first or direct flow positionO
This is a particularly desireable valve geometry since~ when the valve is in the first position, the sound path from the lead plpe 174 through the valve to the main ~ore 176 is completely straight. hhen a note is played with the rotor in the first position, thls valve ad~s no coloration to the sound whatsoever, and the instrument behaves like a straight, or valveless instrument.
12JL~71 I~J1~jlb ~ 1780~ ~4915 When the rotor is moved to the second or diverted flow position, there is a slight bend in ~he sound ~ath at the junction of the primary rotor tube 160 and the main bore 175. But, this bend i5 minor, particularly in comparison tO the sound paths through the mos~ commonly used valves. And, there is a straight path through the primary rotor tube 160 into the one end 178 of the slide loop. There is also a straight path that extends rom the interior of the secondary rotor tube 161 and into the other end 180 of the slide loop~ Thus, even when the rotor is in its second position, there need be no more than one slignt bend in each of the sound paths at the junctions of instrument tubes with the valve casing.
Many instrumentalists would find this embodiment, with its completely straight sound path in the first position, to be superior to the embodiment shown in Figs.
1-?, wherein there is a slight S-curve in the primary rotor tube 60. Such an instrument would have a tone quality equal to a straight horn wnen the valve was not in use, and the sound quality is extremely good even when the valve is rotated to its second position.
It is another advantage of the valves shown in Figs. 10-12 that it can be positionea very closely to other, similar valves. Thus, in a trumpet or french horn, 2S three valves can be arranged in close proximity alony axis "A3" as shown in Fig. 12~ It can be seen that the souna path from the lead pipe 174 to the main bore 176 is a straight line through each of the three primary rotor tubes 160a, 160b, 160c. The instrument pipes which lead 3~ to and from the valves are at convenient angles. And, the valve shafts 170a, 170b, 170c are each at an accessible location and angle. Thus, valves according to the embodiment of Figs. 10-12 are particularly convenient for use in instruments where multiple valves are required.
The rotor 140 illustrated in Fig. 11 is axially-truncated to minimize mass, but could be a whole cone. In this valve, the rotor need not pass through a . ; ` r~
RJ~/jlb ~ 17~D 2491~
small opening if it is to be inspected and cleaned.
Instead, one merely disconnects a finger key linkage (not showll) f.om ~he shaft 170 and rotates the retainer rlng 121 until it disengages the threads 123. The end plate 120, l~ad pipe 174 and one e;na 178 of the slide loop aLe then pulled away from the casing wall 112/ main bore 176 and other end 180 of the slide loop to provide access for removal of the rotor 1400 To reassemble the valve, the procedure is reversed~ The end plate 120, casing outer end 137, and shaft 170 are keyed so that each element of the valve will be in proper alignment after assembly.
A third valve according to the present invention is shown in Figs. 13-17. Thls valve ls a dual valve which includes an additional pair of rotor tubes and additional 5 s2ts of rotor and body apertures.
Certain types of instruments require such dual valves, tne most notable being the double french horn and double baritone. Such an instrument is fitted with two sets of valves with their associated slide loops. Each set of valves is provided with a separate set of slide loops of lengths for one of two specific keys or pitches.
As an example, in the usual double French horn, a primary set of valves may control loops w~-ich pitch the instrulnen~
in the key of F, while the secondary set of valves may control loops which pitch the instrument in the key of B-flat. ~ additional diverter valve is provided to direct the sound path through the desired set of valves.
In practice, each valve is a dual valve which includes two single valves, one from each set, which are linked together so that a single set of finger keys can operate the valves of both the primary and secondary sets~
Dual valves are also utilized in a specific class of instruments called compensating horns. In these it has been found desireable to "compensate" for overall length deficiencies when more than one valve is operated at a time. This compensation is accomplished by providing dual valves to add small secondary slide loops to the sound r' l~JP/jlb ~ 17~0D 24915 ~ 7 ~
path when more than one valve is functioniny. Because compensating horns have previously used two standard single valves linked together to make dual valves, such compensating horns have, of necessity, include tortuous sound paths. A dual valve accordlng ~o the present invention is advantageous in such compensating horns because it includes two single, axial valves in one valve body to simultaneously control the inclusion of both the primary and the secondary slide loop. Such a dual valve reduces the number of valve bodies needed in a compensating horn, and also lessens the tortuousness of horn's sound path.
In the illustrated dual valve, features common to the first valve according to the present invention have the same reference numerals incremented by two hundred.
Features common to the second valve have the same reference numerals incremented by one hundred.
The valve has a casing 210 which includes a substantially frustoconical wall 212 having a base end and a narrowed end. A sleeve 216 is secured on the narrowed end; and a transverse casiny end plate 220 is ~ixed on the base end of the casing by a retainer ring 221. The end plate 220 has flat surfaces positioned perpendicular to the longitudinal axis "A4" of the casing and defines four casing end plate apertures. One of the end plate apertures is the primary casing end plate aperture 224.
Another is a secondary casing end plate aperture 226l the center of which is displaced an equal distance away from the longitudinal axis "A4" as is ~e center of the primary casing end plate aperture 224 A circular tertiary end plate aperture 328 is al~ned coaxially with the longitudinal axis "A4". Also defined by the end plate is a quatenary end plate aperture 329.
The sleeve 216 defines a circular casiny frustrum aperture coaxially aligned with a longitudinal axis "A~"
of the casing wall 212. The casing wall 212 defines primary, secondary and tertiary casiny wall apertures (not shown) at different locations between the casing ends.
l~JP/jlb ~ 1780~ 24'~15 rrhe substantially ~rustoconical rotor 240 is located inside the casing. Qne end of the rotor 240 is a rotor end plate 242 having a circular edge portlon 243 in a radius slightly less than the yreatest inside radius in S the casing wall 212. The rotor end plate 242 includes a primary rotor end plate aperture 244 adopted to register alternatively with the primary casing end plate aperture 224 when the rotor is in a first position and with the secondary casing end plate aperture 226 when tne rotor is in a second position. A secondary rotor end plate aperture 24~ is positioned to rey1ster with the prirnary casing end plate apertuLe 224 when the rotor is in a second position.
The rotor end plate 242 also defines a tertiary rotor end plate aperture 347 which is coaxially alignea with the tertiary body end plate aperture 328 at all times. A quatenary rotor end plate aperture 348 registers with the ~uatenary casing end plate aperture 329 only when the rotor 240 is in the second position.
Extending from the rotor end plate 242 to the other end of the rotor, is a rotor wall 250 which defines a rotor frustrum a~erture 252 at the opposite end from the rotor end plate 242. A primary rotor wall aperture 254, a secondary rotor wall aperture 356 and a tertiary rotor wall aperture 358 are each defined in the wall 250 at locations between the rotor ends. The conical surface portion of the wall 250 seats against the conical surface portion of the casing wall 212 so that the rotor frustrum aperture 252 remains in alignment with the casing frustrum aperture at all times.
The primary rotor wall aperture 254 registers with the primary casing wall aperture only when the rotor is in the second position. The secondary rotor wall aperture 356 is adapted to register alternatively with the secondary casing wall aperture when the rotor is in a first position and with the tertiary casing wall aperture when the rotor is in the second position~ The tertiary I~JP/jlb ~ 1780~ 24915 9 7~
rotor wall apertue 358 is positione~ to register with the secondary casing wall aperture when the rotor is in the second posltlon. Thus, when tne rotor is in the second position, each of the rotor apertures registers with a casing apertureO The rotor apertures and the casin~
apertures preferably correspond exactly in size and shape to one another to minimize the resistance to sound waves passing between the casing and the rotor.
As in the other valves, rotor tubes provide passages for air traveling through the rotor 240. A rigid primary rotor tube 260 extends through the rotor and connects the prlmary rotor end plate aperture 244 with the rotor frustrum aperture 252. Optionally, a cylindrical extension (not shown) of the primary rotor tube 260 could extend into the casing axial aperture so that the aperture would be journaled within the casing aperture. A rigid secondary rotor tube 261 extends through the rotor and connects the secondary rotor end plate aperture 246 to the primary rotor wall aperture 254. The second rotor tube 23 261 can be substantially straight and parallel to the axis "A4" as illustrated, or could be in some other configuration, e.g, curved to extend radially outwardly at an acute angle to the axis "A4" (not shown). A tertiary rotor tube 366 extends through the rotor and connects the tertiary rotor end plate aperture 347 with the secondary rotox wall aperture 356. Preferably, a cylindrical extension 368 of the tertiary rotor tu~e 366 fur~her extends through the tertiary casing end plate aperture 328 so that the extension 328 is journaled within the aperture 328. A quatenary rotor tube 369 extends through the rotor and connects the quatenary rotor end plate aperture 348 with the tertiary rotor wall aperture 358 as shown in ~ig.
17.
Because, at each end of the rotor there is an aperture at the axis of rotation, there is no axial shaft to rotate the rotor. Instead, there is an arm 371 mounted on the rotor to extend through a slot 372 in the casiny end plate 220.
-JP/jlb ~ 178J~ ~4915 ~ ~97~
Fig~ 13 shows how instrul~lent tu~es mount to the third valve according to the yresent invention. A primary lead pipe~ 274 and prirnary main bore 276 connect at opposite ends of the casing. The primary Iead pipe 274 is connected to the primary casing end plate aperture 224.
The prima~y main bore 276 is connected to the casing ~rustrum aperture. A primary slide loop 227 has opposite ends 278, 280 which connect to the ~rimary casing wall aperture, and the secondary casing end plate aperture 226. A secondary lead pipe 381 conn2cts to the tertiary casing end plate aperture 32~. A secondary main bore 383 connects to the second casing wall aperture. A secondary slide loop 385 has opposite en~s 386, 387 which connect to the tertiary casing wall aperture and the quatenary end plate aperture 329. One or both sets or instrument pipes could be reversed whereby sound waves would move through the rotor ~ubes in the opposite directions.
As in other valves according to the invention, the mechanical means for rotating the valve can ~e of a common variety. As shown in Fig. 14, a finger actuated key 292 can be rotatably mounted to a brace on the musical instrument and mechanically connected to the arm 371 in such a manner that movement of tne key causes rotation of the rotor. The key 292 is connected to the arm 371 by 25 a linkaye arm 399 having a ball joint at each en~.
Stops (not shown) limit the movement of the arm 371 and thereby assure positive alignment between the ro~or apertures and the casing apertures when the rotor is in each operation position.
When an instrumentalist moves the key 292~ the rotor rotates about the lon~itudinal axis "A4". ~hen the rotor is in a first, or normal flow posicion, the primary rotor tube 260 connects the primary lead pipe 274 directly to the primary main bore 276. And, the tertiary rotor tube 366 connects the secondary lead pipe 381 directly to the secondary main bore 383.
" ~JP/jlb ~ 1780~ 24915 ~Z~7~
By depressing the key 292 the rotor is rotated about the axis "A4" to the seco~d or diver~ed flow position wherein the secondary rotor tube 261 connects the primary lead pipe 274 with one end 278 of the prlmary slide loop; and the primary rotor tube 260 connects the other end 280 of the primary slide loop with the prlmary maln bore 276. Also, when the rotor is in the second position, the tertiary rotor tube 366 connects the secondary lead pipe 381 with one end 386 of the slide loop 385; and the quatenary rotor tube 369 connects the other end 3~7 of the secondary slide loop with the secondary main bore 383.
Thus, when the valve is in the ~irst position the sound waves can travel directly between the primary lead pipe 274 and primary main bore ~76; they also can travel directly between secondary }ead pipe 381 and second main bore 383. When the valve is in the secon~ position, sound waves must pass through the primary slide loop 277 when traveling between the primary lead pipe 274, and the primary main bore 276. Likewise, sound waves must pass through the secondary slide loop 335 when traveling between the secondary lead pipe 381 and the secondary main bore 383.
While I have shown and described preferred embodiments of my invention, it will be apparent to those skilled in the art that changes and modifications may be made without departing from my invention in its broader aspects. For example, efficient operation of valves according to the present invention is not affected by reversing the structure so that the lead pipe of a musical instrument is connected to the frustrum aperture and the main bore is connected to the primary casing end plate aperture. In the dual valve of Fig. 13, either one o~
both pairs of instrument tubes may be reversed. Such reversed valves will operate in substantially the same fashion as the valves illus~rated, excep~ that the flow of sound waves through the valve will be reversed.
- 21 ~
BRIEF SU~ARY OF THE INVENTION
This invention relates to a rotary fluid flow switch and more specifically to a rotary air valve of a musical instrument.
Rotary valves are highly regarded for use in musical instruments due to their quick action and relative simplicity of structure as compared to piston ~ype valves. Some prior rotary valves are compact and lightweight, but suffer from the disaavantage that they add overtones to the sound of the instrument when played.
These overtones are produced either inside the valve rotor or at the junction of the valve rotor with the instrument tubing, wherever there is a sharp bend or substantial variation in cross-sectional shape of the air passage.
When sound waves traveling through an instrument's sound passage are required to make sharp turns or pass through regions of varying cross-sectional shape, certain por r ions of the waves ref~lect off the inside wall of the passageO
Such a partial reflection reduces the energy of the fundamental wave and produces an undesirable overtone.
The present invention is a valve which adds few unwanted harmonics to a musical instrument's tone and weighs less than any prior valve of comparable acoustic qualityO The lead pipe and main bore of the instrument RJP/jlb ~ L780~ 24'~15 align axially with the passages of the valve rotor so that the sound waves enter, pass through~ and leave the valve ~ hout substantially char~ging direction or being deflected off the passage walls. ~uch a valve can be S constructed with a rotor having only ~wo passages, ~hich extend straight throuyh the rotor. Alternatively, one or both of such passages may be slightly curved.
The rotor has an outer surface portion tha~ is tapered, preferably generally conical. This rotor is received by a casing having a flared inner surface portion that conforms in shape to the outer sur~ace portion of the rotor. The tapered and flared su!face portions engage each other such that the rotor is maintained in propec axial alignment during its rotation. Because the rotor rotates on a conical surface portion, the entire vaLve can fit within a casing that is generally conical in shape and has but a single casing end plate. Such a valve weights less and occupies less volume than a cylindrical rotary valve of the same diameter. Because the entire valve can be tapered, at least one of the sound passageways can be very short and yet extend substantially stralght through the rotor. The valve thus can be used to mount very short slide loops, with no reduction in sound yuality.
A valve according to the present invention can have as few as three primary elements: (1) a casing having a flared inner surface; (2) a tapered rotor that fits in the casing and can be removed for cleaning; and ~3) some means to releasably re~ain the rotor in the casing.
3Q In one embodiment, the casing is partially closea at its base by an end wall; and the rotor is axially-truncated so that it can be removed through the uncovered portion of the casing base. Another embodiment includes a casing that is completely open at its base, the 3~ rotor being secured by an end plate detachably mounted over the opening b~ a threaded retainer rin~.
73~
The present invention provides a rotary valve for a musical wind instrument having a slide loop, an instrument pipe wi-th a mouthpiece at one end and an instrument pipe termina-ting in an instrument bell.
The valve comprises a casing and a substantially frusto-conical rotor rotatable in the casing. The casing includes a substantially frustoconical casing wall having a base and a narrowed end, the wall -tapering directly toward and defining an ax1al frustrum aperture at the narrowed end and a casing wall aperture at a location between the base and the narrowed end, and a -transverse casing end plate at the base of the wall, the end plate defining primary and secondary end plate apertures. The rotor has a primary rotor passage which connects the primary end plate aperture to the frustrum aperture when the rotor is in a first position and which connects the secondary end plate aperture with the frustrum aperture when the rotor is rotated to a second position. The rotor also has a secondary rotor passage which connects the primary end plate aperture to the wall aperture when the rotor is in the second position.
The primary end plate aperture connects to one of the instrument pipes. The frustrum aperture connects to the other of the instrument pipes, the secondary end plate aperture connects to one end of the loop, and the wall aperture connects to the other end of the loop.
'97~
RJP/jlb ~ 178~D 24915 It is an object of the present inventi~n to provide a musical instrument rotary valve which is lightweight, of simple design, requires a minimum of parts, is inexpensive and easy to construct.
A further object is to provide such a valve with a rotor that can be easily removed for cleaning without the use of tools or with one simple tool at most~
Also, an object of the invention is to improve the acoustic performance of all valved brass wind instruments, such as trumpets, alto horns, French horns, trombones, baritones and tubas, by providirlg a valve which does not ha~e the abruptly angled sound passages of most prior rotary and piston valves.
An additional object of this invention is therefore to provide a rotary valve having passages which extend in a straight or substantially straight path therethrough and are of a uniform circular cross section throughout their entire length.
Another ob~ect is to provide a rotary valve in which the instrument's lead pipe and main bore align axially with the passages through the valve's rotor.
Yet another object is to provide certain rotary valves where the lead pipe and main bore are in axial alighnment with each other at the locations where they attach to the valve so that when the rotor is in one operating position there is a straight passage from the lead pipe to the main bore.
It is also an object to provide a rotary valve having inlet and outlet ports configured such that multiple valves can be located in close proximity with a substantially straight sound path extending from ~he lead pipe, through all of the valves, to the main bore.
A further object is to provide a rotary valve having a rotor which requires only two passages extending 3S axlally therethrough.
A still further object of the invention is to provide a r~tary valve having a rotor passage which, at ~.Z~ 7~
IWP/jlb ~ 1780~ 24915 one end, is coaxial to the axis of rotor rota~ion.
Other objects, advanl:ages and features of this invention will become apparent to those skilled in ~he art upon reading the following specification.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
Fig. 1 is a side elevation of a B-flat trombone incorporating a first valve according to the present invention;
Fig. 2 is an enlarged, isometric, exploded view of the valve shown in Fig. l;
Fiy. 3 is a plan view on a further enlarged scale of the valve shown in Figs. 1 and 2;
Fig. 4 i5 a sectional view taken along line 4-4 Of Fig. 3;
Fig. 5 is a sectional view taken along line 5-5 of Fig. 4, the view including a vertical sectional view of a rotor in a first or direct flow position;
Fig. 6 is a sectional view taken along line 6-6 of Fig. 5;
Fig. 7 is a vertical, sectional view of the rotor shown in Fig. 5, the rotor being shown as rotated ~o a seSond or diverted flow position;
Fig. 8 is an isometric schematic view showing the flowpath of a valve according to the present invention with a rotor in a first or direct flow position;
Fig. 9 is an isometric schematic view showing the 10wpath of the valve of Fig. 8 with the rotor in a second or diverted flow position;
3~ Fig. 10 is a side elevation of a B-flat trol~lbone incorporating a second valve according to the presen~
invention, Fig. 11 is an enlarged, isometric, exploded view of the valve shown in Fig. 10;
Fig. 12 is a fragmentary plan view of a musical wind instrument incorporating three of the valves shown in Fig. 10 in series;
3~
RJP/~lb B 1780D 24gl5 Fig. 13 is a fragmentary plc~n view of a musical wind instrument incorporating third valve according to the present invention for simultaneously engaging two slide 1 oo~s;
5Fig. 14 is a partial sectional view taken along line 14-14 of Fig. 13;
Fig~ 15 is a sectional view taken along line 15-15 of Fig. 13;
Fig. 16 is a sectional view of the valve rotor 10 shown in Fig~ 15 taken along lines 16-16 of Fig. 15, the view being a ver~ical sectional view of the rotor in a first or direct flow position; and Fig. 17 is a sectional view of the valve rotor shown in ~ig. 15 taken along lines 17-17 of Fig. 15, the 15 view being a vertical sectional view of the rotor in a second or diverted flow position.
DETAILED DESCRIPTION
Rotary valves for selectively inserting and removing a slide loop from the sound path of a musical instrument are shown in U.S. Patent No. 4,112,806 issued September 12, 1378, U~S. Patent No. 4,~13,37], issued July 22, 1980, and U.S. Patent No. 4,299,15Ç issued November 10, 1981. Each such valve inclu~es a rotor having at least two sound passages extending therethrough, whi~h are no more than slightly curved. The passages align axially with the instrument's lead pipe, main bore, and slide loop ends so that a ~inimum of undesired harmonics are added to the tone of the instrument due to presence of the valve in the sound path. Each of these previous valves are simple 33 in construction and have a superior sound path.
Valves according to the present invention have the aforesaid favorable features and new features which provide benefits o a different nature. A valve according to the present invention has a rotor with an outer surface 97~
I~JL~/jlb u 17~1) 24(~15 which provides a contact face that is detined in a generaliy conical surface. The face may be defined in any tapered surface that is circular in ri~ht cross sectlon;
but a tr~le cone is preferred~ The rotor is contained within a casiny which has an inner surface portion with a contact surface that conforms in shape to the same generally conical surface as does the rotor surface. Due to the conical shape of the contact surfaces, the rotor is self-centering within the casing ana will have a low mass and thus a low inertia. The lightweight rotor responds to an instrumentalists finger movements more quickly than prior rotors of greater mass.
Because they can be constructed using a minimum number of parts, valves according to the present invention can be very low in total weight. One preferred valve has only three basic separable parts, a casing, a door plate, and a rotor, as shown in Figs~ 1-7 of the drawillg. The valve shown in Figs. 10~12 has only a casiny, a door plate, a rotor and a retaining ring. Despite the simplicity and low weight of such preferred valves, each has a rotor that is easily removable for cleaning.
As illustrated in ~igs. 1-7, a first valve according to the present invention has a cacing 10 which includes a substantially frustoconical casing wall 12 having a base end and a narrowed end, a sleeve 16 secured on the narrowed end, and a transverse casing end plate 14 fixed on the base end of the casing. The end plate 14 has flat surfaces positioned perpendicular to a longitudinal axis "Al" of the casing and defines two casing end plate apertures. One of the end plate apertures is a primary casing end plate aperture 24 having an axis which is parallel to but displaced from the axis "Al". The other is a secondary casing end plate aperture 26 the center of which is displaced an equal distance away from the longitudinal axis "Al" as is the cen~er of the primary casing end plate aperture 24.
~ f~
I~JP/jlb ~ 17~0D 24915 The end plate 14 of the casing shown ln Figs.
1-6, only partially closes the base end of the casing. As best seen in Fig. 2, the end plate 14 leaves an o~ening 27 into the casing through which the rotox may be removed for inspection and cleaningO In order to allow suflicient Loom for the passage of the rotor, it is preferred that the end plate 14 cover an area contained entirely wlthin two adjacent quadrants of the base end of the casing. A
door plate 28 mounts detachably alongside the end plate 14 over the opening 27 at the one end of the casing wall 12 and is held in place by screws 29~ The door plate 28 includes a circular shaft aperture 30 which is positioned coaxially to the longitudinal axis "Al" when the aoor plate i5 mounted on the casing ~all 12. The sleeve 16 defines a circular, axial casing frustrum aperture 32 coaxially aligned with the iongitudinal axis "Al" of the casing wall 12. The casing wall 12 defines a casing wall aperture 34 at a location between the casing ends.
The casing wall 12 includes a right frustoconical portion 35 and a cylindrical portion 36 whlch extends from the base of the frustoconical portion 35 to a circular casing outer end 37 which is the base end of the casiny wall 12. The frustoconical portion 35 and cylindrical portion 36 have a common axis which coincides with the axis "Al".
Inside the casing are two opposed interior contact faces. The interior of the casing wall 12 provides one interior contact face which is an area defined in a tapered surface of circular cross section.
In the illustrated embodiment, the frustoconical portlon 35 has a flared, substantially conical inner surface 3~
that provides the one contact face and which serves as a coaxial, concave seat for the rotor. The other contact face is the inner surface 3~ of the casing end plate 14.
A substantially frustoconical rotor indicated generally at 40, is located insiae tne casing. At one en~
of the rotor 40 is a rotor end plate 42 having a curved XJP/jlb B 1780D 24915 l~lU971 edge portion 43 in a ra~ius slightly less than the greatest inside radius of the casing wall 12. This rotor end plate lS positioned with one of its flat surfaces adjacent inner surface 39 of the casing end plate 14. The rotor end plate 42 includes a primary rotor end plate aperture 44 adapted to register alternaLely with the primary casiny end pLate aperture 24 when the rotor is in a first position and with the secondary casing end plate aperture 26 when Ae rotor is in a second position. The rotor end plate 42 also includes a secondary-rotor end plate aperture 46 which is positioned to reg1ster with the primary casing end plate aperture 24 when the rotor is in the second position.
Extending from the rotor end plate 42 to the other end of the rotor is a rotor wall 50 which defines a rotor frustrum aperture 52 at the end opposite the rotor end plate 42. The wall has a tapered, arcuate outer surface~ In the illustrated embodiment, the rotor wall 5 is substantially frustoconical. ~ rotor wall aperture 54 is defined in the wall 50 at a location between the rotor ends.
The illustrated casing wall 12 has an inner surface at least a portion of whiGn has the shape of a circular cone ~ith the same angle of generation as that of the conically-shaped portion of ~he surface of the rotor wall 50. The conical surface portion oE the wall 50 seats against the conical surface portion of the casing wall 12 so that the rotor frustrum aperture 52 remains in alignment with the casing frustrum aperture 32 at all times. The rotor wall aperture 54 registers with the casing wall aperture 34 only when the rotor 40 is in the second position. When the rotor is in tne second position, each of the rotor apertures registers with a casing aperture. The rotor aper~ures and the casing apertures preferably correspond exactly in size and shape to one another to minimize the resistance to soundhaves passing between the casing and rotor.
97~
~WP~jlb B 1780D 24915 Rotor tubes provide passages for air traveling - through the rotor 40. A rigid primary rotor tube 60 extends throuyh the rotor and connects the primary rotor end plate aperture 44 with the rotor frustrum aperture 52. Optionally, a cylindric~1 extension (not shown) of the primary rotor tube 60 could extend into the casing axial aperture 32 so that the extension would be journaled within the aperture 32 and the sleeve 16.
A rigid secondary rotor tube 61 extends through the rotor and connects the secondary rotor end plate aperture 46 to the rotor wall aperture 54. The axis of this secondary rotor tube 61 is substantially perpendicular to the rotor end plate 42 where they join and is coaxial with the secondary rotor end plate aperture 46~ Where the secondary rotor tube 61 joins the rotor wall aperture 54, they are coaxial. At this location, the secondary ro~or tube 61 of the illustrated embodiment extends radially outwardly at an acute angle to the axis "Al" as best seen in FigO 7. Although hollow tubes provide the sound passayes of the preferred rotor, other constructions could be used. For instance, a solid rotor having passages extending therethrough, would be suitable but not preferred due to its greater mass.
The iliustrated rotor is specifically shaped for use in the casing previously described. The rotor wall 50 includes a right frustoconical portion 62 having a base end and a narrowed end, and a right cylindricaL portion 63 which extends from the base of the frustoconical portion 62. The rotor end plate 42 is secured to the outer end of the cylindrical portion 63. The frustoconical portion 62 and cylindrical portiosl 63 have a common axis which coincides with the axis "Al" when the rotor is installed inside the casing.
To lower rotor size and weight and allow for easy removal, the rotor wall 50 is axially-trunca~ed so that it has an axially-extending edge 64. An axially extending rotor side wall 65 is mouslted on the rotor wall 50 at the 1 ;~.L~971 RJP/jlb B 178~D 24915 edge 64 to enclose the rotor. A transverse section OL the rotor, taken through the rotor side wall 65, woul~ show the outer surface of the rotor as a ma~or arc ~ormed by the rotor wall 50 and a secant formed by the side wall 65.
The rotor has two o~posed exterior contact faces which face the interior contact faces of the casing. The outside of the rotor wall 50 provides one exterior contact face which is an area defined in a tapered surface of circular cross section that conforms to the surface whlch defines the one interior contact face of the casing. In the illustrated rotor, the substantiaLly conical outer surface 67 of the rrustoconical portion 62 provides a contact face that mates with the inner surface 38 of the casing. Specifically, the tapered outer surface 67 seats in the rotor seat formed by inner surface 38 so that th~
rotor is centered for rotation relative to the casing.
Proper rotor alignment is best achieved if at least a portion of each tapered contact face is a major arc in cross section. Preferably a portion of at least one of said contact faces is a complete circle in cross section at the narrowed ends of the casing and rotor as shown in Fig. 6. The other rotor contact face is provided by the outer surface 68 of the rotor end wall 42 and is positioned to face the inner surface 39 of the casing end wall 14.
A shaft 70, extending froln the outer side of the rotor end plate 42, is coaxial to the longitudinal axis "Al". The shaft 70 extends through tne sha~t aperture 30 so that the rotor can be rotated about the axis "Al"
by rotating the shaft 70.
The best tone quality is achieved if sound waves traveling through the valves of the musical instrumen~
encounter a minimum amount of resistance. By mounting the instrument tubes so that their axes register with the tube axes at the points where the tubes are mounted on the casing, a minimum amount of resistance is encountered during the transfer of sound waves between the instrument 7~L
I~JP/jlb ~ 17~ 24915 tubes an~ the rotor passayes. Resistance inside the rotor passages is low because the tubes 60, 61 are substantially straight and of a uniform, circular cross section throughout their entire length.
The primary rotor tube 60 is shaped as a slight S-curve and has end portions positioned to be substantially parallel to the axis "Al". An alternative to the S-shaped primary rotor tube 60 is a straight tube (not shown) extending diagonally between tne primary rotor end plate aperture 44 and the rotor frustrum aperture 52.
Such a diagonal tube would provide a substantially straight soundpath; but the ends of such a straight diagonal primary rotor tube would not align axially with the illustrated instrument tubes so there would be some resistance to the transfer of sound waves between tne primary rotor passage and the instrument tubes.
The secondary rotor tube 61 curves gently as it e~tends between the secondary rotor end plate aperture 46 and rotor wall aperture 54. It is desirable to maximlze the radius of curvature to minimize resistance. Because it extends tnrough a conically shaped portion o~ rotor wall 50, the tube 61 can have a large radius of curvature or even be straight (not shown)~ The conical shape of the valve illustrated is also advantageous because, at a given tube size, such a valve occu~ies less space ana weighs less than any other valve having comparably straight sound passages.
Such valves according to the present invention are well suited for use in compact instruments and instruments requiring short sllde loops. The distance between the primary rotor end plate aperture 44 and rotor wall aperture 54 is so little that even the shortest slide loop can be positioned with it's ends in registry with those apertures.
Instrument tubes are mounted to the casing so that they connect with the casing apertures. Preferably the tubes and apertures are in axial alignment so that a l~P/jlb ~ 1780D ~915 ~ 9~
minimum amount of resistance is encountered during the transfer of sound waves between the instrument tubes and the rotor passages. The drawing figures show the first valve according to the present invention connected with tubes which cGrrespond to the tubes of a musical instrument. A lead pipe 74 and main bore 76 connect to opposite ends of the casing. The lead pipe 74 exten~s from the mouthpiece of the instrument and is connected to the primary casing end plate a~erture 24 which is located at a first of the opposite ends of the illustrated casing. The main bore 76 of the instrument connects to the casing frustrum aperture 32 which is located at a second of the opposite ends ~f the illustrated casingO A
slide loop 77 has opposite ends 7~, 80 which connect to the casing wall aperture 34 and the secondary casing end plate aperture 26 which is at one of the opposite ends, in this instance the first of such ends.
Fig. 1 depicts a valve according to the present invention incorporated in a musical instrument. More specifically, Fig. 1 shows a B-flat trombone which includes a single slide loop 77. By rotating the valve, the slide loop 77 may be added to the sound path so that the fundamental pitch of the trombone is lowered to the key of E-flat. The trombone has a mouthpiece 38 and a slide 90 which are portions of the lead pipe 74. The lead pipe connects to the primary casing end plate aperture 24 of the valve. One end 78 of the slide loop 77 is connected to the casing wall aperture 34. The other end 80 is connected to the secondary casing end plate aperture 26. The main bore 76 is connected to the casing frustrum aperture 32.
Means are provided on the instrument for r~tating the valve shat and rotor. Such rotating means can be of a common variety, as shown in Fig. 1, that em~loys a finger actuated key 92 rotatably mounted to a brace of the instrument and mechanically connected to the shaft 70 in such a manner that movement of the key causes rotation of ~P/jl~ ~ 17~0~ 2~915 ~ 97~
the shaft. Fig. 2 shows an arranyement where a crank ~4 - connects to the shaft and has a ball 96 which forms a part of a ball joint ~ith a linkage (not shown) which connects with the finger actuated key. One or more stops 98 may be provided to limit movement of the crank 94 and thereby assure positive alignment between rotor apertures and casing apertures.
When the instrumentalist moves the key 92, the rotor rotates about the longitudinal axis "Al" between l~ the positions illustrated in Figs. 8 and 9 wherein the rotor 40 appears in broken lines. Fig. 8 shows the rotor in the normal flow or first position. In this position, the primary rotor tube 60 connects the lead pipe 74 directly to the main bore 76.
By depressing the key 92, the rotor is rotated about the axis "Al" to the second or diverted flow position shown in Fig. 9; the secondary rotor tube 61 connects the lead pipe 74 with one end 78 of the slice loop; and the primary rotor tube 60 connects the other end 80 of the slide loop with the main bore 76. Thus, when the valve is in the first position, the sound waves can travel directly between the lead pipe 74 and the main bore 76. When the valve is in the second position, sound waves must pass through the slide loop 77 when traveling between the lead pipe 74 and the main bore 76.
The rotor may be removed for inspection and cleaning by removing the scre~s 29 and disconnecting the crank 94 from the shaft 70. When this is done, the aoor plate 28 can be removed to release the shaft 70. Using the fingers, the shaft is rotated until the rotor ena plate 42 aligns with the opening 27 through the base of the rotor casing whereupon the rotor can be pulled out through the opening.
To reinstall the rotor, tne procedure is reversed. The rotor is held in the position shown by broken lines in Fig. 2, and pushed through the openlng to the point where the conical surfaces engage. Once I~J~jL~ 13 17~u 2~15 ~ 97~
inserted, the rotor is finger-rotated to its operating ~osition after which the door plate 28, screws 29, and crank 94 are returned to their places.
FigsO 10-12 illustrate a second valve according to the presen~ invention ~hich is closely related to the valve shown in Fiys~ 1-7~ Each feature of the second valve that is common to a feature of the first valve bears the same reference numeral incremented by one hundred.
The second valve has a casing 110 with a substantially frustoconical wall 112 with a longitudinal axis "A2".
An end plate 120 having flat surfaces positioned - perpendicular to the axis "A2" defines the two casing end plate apertures 124, 126, displaced an equal distance away from the lonyitudinal axis "A2". The casing shown in Figs. 10-12 has an end plate 1~0 which closes the base end of the casing. A retainer rin~ 121 secu~es the end plate 120 to the casing wall 112~ The ring has interior threads 122 which mate with exterior threaas 123 on the casing wall 112. The end plate 120 includes a circular shaft aperture 130 which is positioned coaxiaLly to the longitudinal axis "A2" when the end plate is moun~ed on the casing wall 112.
A sleeve 116 defines a circular, axial casing frustrum aperture (not shown) that is coaxially aligned with the longitudinal axis "A2" of the casing wall 112.
Unlike other embodiments, however~ the sleeve 116 has an axis 11~311 at an acute angle to the axis of rotation "A2". As seen in Figs. 11 and 12, the lead pipe 174 and main bore 176 are also coaxial to axis "A3", as is the primary rotor tube 160 when the valve is in the first or direct flow positionO
This is a particularly desireable valve geometry since~ when the valve is in the first position, the sound path from the lead plpe 174 through the valve to the main ~ore 176 is completely straight. hhen a note is played with the rotor in the first position, thls valve ad~s no coloration to the sound whatsoever, and the instrument behaves like a straight, or valveless instrument.
12JL~71 I~J1~jlb ~ 1780~ ~4915 When the rotor is moved to the second or diverted flow position, there is a slight bend in ~he sound ~ath at the junction of the primary rotor tube 160 and the main bore 175. But, this bend i5 minor, particularly in comparison tO the sound paths through the mos~ commonly used valves. And, there is a straight path through the primary rotor tube 160 into the one end 178 of the slide loop. There is also a straight path that extends rom the interior of the secondary rotor tube 161 and into the other end 180 of the slide loop~ Thus, even when the rotor is in its second position, there need be no more than one slignt bend in each of the sound paths at the junctions of instrument tubes with the valve casing.
Many instrumentalists would find this embodiment, with its completely straight sound path in the first position, to be superior to the embodiment shown in Figs.
1-?, wherein there is a slight S-curve in the primary rotor tube 60. Such an instrument would have a tone quality equal to a straight horn wnen the valve was not in use, and the sound quality is extremely good even when the valve is rotated to its second position.
It is another advantage of the valves shown in Figs. 10-12 that it can be positionea very closely to other, similar valves. Thus, in a trumpet or french horn, 2S three valves can be arranged in close proximity alony axis "A3" as shown in Fig. 12~ It can be seen that the souna path from the lead pipe 174 to the main bore 176 is a straight line through each of the three primary rotor tubes 160a, 160b, 160c. The instrument pipes which lead 3~ to and from the valves are at convenient angles. And, the valve shafts 170a, 170b, 170c are each at an accessible location and angle. Thus, valves according to the embodiment of Figs. 10-12 are particularly convenient for use in instruments where multiple valves are required.
The rotor 140 illustrated in Fig. 11 is axially-truncated to minimize mass, but could be a whole cone. In this valve, the rotor need not pass through a . ; ` r~
RJ~/jlb ~ 17~D 2491~
small opening if it is to be inspected and cleaned.
Instead, one merely disconnects a finger key linkage (not showll) f.om ~he shaft 170 and rotates the retainer rlng 121 until it disengages the threads 123. The end plate 120, l~ad pipe 174 and one e;na 178 of the slide loop aLe then pulled away from the casing wall 112/ main bore 176 and other end 180 of the slide loop to provide access for removal of the rotor 1400 To reassemble the valve, the procedure is reversed~ The end plate 120, casing outer end 137, and shaft 170 are keyed so that each element of the valve will be in proper alignment after assembly.
A third valve according to the present invention is shown in Figs. 13-17. Thls valve ls a dual valve which includes an additional pair of rotor tubes and additional 5 s2ts of rotor and body apertures.
Certain types of instruments require such dual valves, tne most notable being the double french horn and double baritone. Such an instrument is fitted with two sets of valves with their associated slide loops. Each set of valves is provided with a separate set of slide loops of lengths for one of two specific keys or pitches.
As an example, in the usual double French horn, a primary set of valves may control loops w~-ich pitch the instrulnen~
in the key of F, while the secondary set of valves may control loops which pitch the instrument in the key of B-flat. ~ additional diverter valve is provided to direct the sound path through the desired set of valves.
In practice, each valve is a dual valve which includes two single valves, one from each set, which are linked together so that a single set of finger keys can operate the valves of both the primary and secondary sets~
Dual valves are also utilized in a specific class of instruments called compensating horns. In these it has been found desireable to "compensate" for overall length deficiencies when more than one valve is operated at a time. This compensation is accomplished by providing dual valves to add small secondary slide loops to the sound r' l~JP/jlb ~ 17~0D 24915 ~ 7 ~
path when more than one valve is functioniny. Because compensating horns have previously used two standard single valves linked together to make dual valves, such compensating horns have, of necessity, include tortuous sound paths. A dual valve accordlng ~o the present invention is advantageous in such compensating horns because it includes two single, axial valves in one valve body to simultaneously control the inclusion of both the primary and the secondary slide loop. Such a dual valve reduces the number of valve bodies needed in a compensating horn, and also lessens the tortuousness of horn's sound path.
In the illustrated dual valve, features common to the first valve according to the present invention have the same reference numerals incremented by two hundred.
Features common to the second valve have the same reference numerals incremented by one hundred.
The valve has a casing 210 which includes a substantially frustoconical wall 212 having a base end and a narrowed end. A sleeve 216 is secured on the narrowed end; and a transverse casiny end plate 220 is ~ixed on the base end of the casing by a retainer ring 221. The end plate 220 has flat surfaces positioned perpendicular to the longitudinal axis "A4" of the casing and defines four casing end plate apertures. One of the end plate apertures is the primary casing end plate aperture 224.
Another is a secondary casing end plate aperture 226l the center of which is displaced an equal distance away from the longitudinal axis "A4" as is ~e center of the primary casing end plate aperture 224 A circular tertiary end plate aperture 328 is al~ned coaxially with the longitudinal axis "A4". Also defined by the end plate is a quatenary end plate aperture 329.
The sleeve 216 defines a circular casiny frustrum aperture coaxially aligned with a longitudinal axis "A~"
of the casing wall 212. The casing wall 212 defines primary, secondary and tertiary casiny wall apertures (not shown) at different locations between the casing ends.
l~JP/jlb ~ 1780~ 24'~15 rrhe substantially ~rustoconical rotor 240 is located inside the casing. Qne end of the rotor 240 is a rotor end plate 242 having a circular edge portlon 243 in a radius slightly less than the yreatest inside radius in S the casing wall 212. The rotor end plate 242 includes a primary rotor end plate aperture 244 adopted to register alternatively with the primary casing end plate aperture 224 when the rotor is in a first position and with the secondary casing end plate aperture 226 when tne rotor is in a second position. A secondary rotor end plate aperture 24~ is positioned to rey1ster with the prirnary casing end plate apertuLe 224 when the rotor is in a second position.
The rotor end plate 242 also defines a tertiary rotor end plate aperture 347 which is coaxially alignea with the tertiary body end plate aperture 328 at all times. A quatenary rotor end plate aperture 348 registers with the ~uatenary casing end plate aperture 329 only when the rotor 240 is in the second position.
Extending from the rotor end plate 242 to the other end of the rotor, is a rotor wall 250 which defines a rotor frustrum a~erture 252 at the opposite end from the rotor end plate 242. A primary rotor wall aperture 254, a secondary rotor wall aperture 356 and a tertiary rotor wall aperture 358 are each defined in the wall 250 at locations between the rotor ends. The conical surface portion of the wall 250 seats against the conical surface portion of the casing wall 212 so that the rotor frustrum aperture 252 remains in alignment with the casing frustrum aperture at all times.
The primary rotor wall aperture 254 registers with the primary casing wall aperture only when the rotor is in the second position. The secondary rotor wall aperture 356 is adapted to register alternatively with the secondary casing wall aperture when the rotor is in a first position and with the tertiary casing wall aperture when the rotor is in the second position~ The tertiary I~JP/jlb ~ 1780~ 24915 9 7~
rotor wall apertue 358 is positione~ to register with the secondary casing wall aperture when the rotor is in the second posltlon. Thus, when tne rotor is in the second position, each of the rotor apertures registers with a casing apertureO The rotor apertures and the casin~
apertures preferably correspond exactly in size and shape to one another to minimize the resistance to sound waves passing between the casing and the rotor.
As in the other valves, rotor tubes provide passages for air traveling through the rotor 240. A rigid primary rotor tube 260 extends through the rotor and connects the prlmary rotor end plate aperture 244 with the rotor frustrum aperture 252. Optionally, a cylindrical extension (not shown) of the primary rotor tube 260 could extend into the casing axial aperture so that the aperture would be journaled within the casing aperture. A rigid secondary rotor tube 261 extends through the rotor and connects the secondary rotor end plate aperture 246 to the primary rotor wall aperture 254. The second rotor tube 23 261 can be substantially straight and parallel to the axis "A4" as illustrated, or could be in some other configuration, e.g, curved to extend radially outwardly at an acute angle to the axis "A4" (not shown). A tertiary rotor tube 366 extends through the rotor and connects the tertiary rotor end plate aperture 347 with the secondary rotox wall aperture 356. Preferably, a cylindrical extension 368 of the tertiary rotor tu~e 366 fur~her extends through the tertiary casing end plate aperture 328 so that the extension 328 is journaled within the aperture 328. A quatenary rotor tube 369 extends through the rotor and connects the quatenary rotor end plate aperture 348 with the tertiary rotor wall aperture 358 as shown in ~ig.
17.
Because, at each end of the rotor there is an aperture at the axis of rotation, there is no axial shaft to rotate the rotor. Instead, there is an arm 371 mounted on the rotor to extend through a slot 372 in the casiny end plate 220.
-JP/jlb ~ 178J~ ~4915 ~ ~97~
Fig~ 13 shows how instrul~lent tu~es mount to the third valve according to the yresent invention. A primary lead pipe~ 274 and prirnary main bore 276 connect at opposite ends of the casing. The primary Iead pipe 274 is connected to the primary casing end plate aperture 224.
The prima~y main bore 276 is connected to the casing ~rustrum aperture. A primary slide loop 227 has opposite ends 278, 280 which connect to the ~rimary casing wall aperture, and the secondary casing end plate aperture 226. A secondary lead pipe 381 conn2cts to the tertiary casing end plate aperture 32~. A secondary main bore 383 connects to the second casing wall aperture. A secondary slide loop 385 has opposite en~s 386, 387 which connect to the tertiary casing wall aperture and the quatenary end plate aperture 329. One or both sets or instrument pipes could be reversed whereby sound waves would move through the rotor ~ubes in the opposite directions.
As in other valves according to the invention, the mechanical means for rotating the valve can ~e of a common variety. As shown in Fig. 14, a finger actuated key 292 can be rotatably mounted to a brace on the musical instrument and mechanically connected to the arm 371 in such a manner that movement of tne key causes rotation of the rotor. The key 292 is connected to the arm 371 by 25 a linkaye arm 399 having a ball joint at each en~.
Stops (not shown) limit the movement of the arm 371 and thereby assure positive alignment between the ro~or apertures and the casing apertures when the rotor is in each operation position.
When an instrumentalist moves the key 292~ the rotor rotates about the lon~itudinal axis "A4". ~hen the rotor is in a first, or normal flow posicion, the primary rotor tube 260 connects the primary lead pipe 274 directly to the primary main bore 276. And, the tertiary rotor tube 366 connects the secondary lead pipe 381 directly to the secondary main bore 383.
" ~JP/jlb ~ 1780~ 24915 ~Z~7~
By depressing the key 292 the rotor is rotated about the axis "A4" to the seco~d or diver~ed flow position wherein the secondary rotor tube 261 connects the primary lead pipe 274 with one end 278 of the prlmary slide loop; and the primary rotor tube 260 connects the other end 280 of the primary slide loop with the prlmary maln bore 276. Also, when the rotor is in the second position, the tertiary rotor tube 366 connects the secondary lead pipe 381 with one end 386 of the slide loop 385; and the quatenary rotor tube 369 connects the other end 3~7 of the secondary slide loop with the secondary main bore 383.
Thus, when the valve is in the ~irst position the sound waves can travel directly between the primary lead pipe 274 and primary main bore ~76; they also can travel directly between secondary }ead pipe 381 and second main bore 383. When the valve is in the secon~ position, sound waves must pass through the primary slide loop 277 when traveling between the primary lead pipe 274, and the primary main bore 276. Likewise, sound waves must pass through the secondary slide loop 335 when traveling between the secondary lead pipe 381 and the secondary main bore 383.
While I have shown and described preferred embodiments of my invention, it will be apparent to those skilled in the art that changes and modifications may be made without departing from my invention in its broader aspects. For example, efficient operation of valves according to the present invention is not affected by reversing the structure so that the lead pipe of a musical instrument is connected to the frustrum aperture and the main bore is connected to the primary casing end plate aperture. In the dual valve of Fig. 13, either one o~
both pairs of instrument tubes may be reversed. Such reversed valves will operate in substantially the same fashion as the valves illus~rated, excep~ that the flow of sound waves through the valve will be reversed.
- 21 ~
Claims (23)
1. A rotary valve for a musical wind instrument having a slide loop, an instrument pipe with a mouthpiece at one end and an instrument pipe terminating in an instrument bell, said valve comprising:
a casing including (a) a substantially frustoconical casing wall having a base and a narrowed end, said wall tapering directly toward and defining an axial frustrum aperture at said narrowed end and a casing wall aperture at a location between said base and said narrowed end, and (b) a transverse casing end plate at said base of said wall, said end plate defining primary and secondary end plate apertures; and a substantially frustoconical rotor rotatable in said casing having (a) a primary rotor passage which connects said primary end plate aperture to said frustrum aper-ture when said rotor is in a first position and which connects said secondary end plate aperture with said frustrum aperture when said rotor is rotated to a second position, and (b) a secondary rotor passage which connects said primary end plate aperture to said wall aperture when said rotor is in said second position, said primary end plate aperture connecting to one of said instrument pipes, said frustrum aperture connecting to the other of said instrument pipes, said secondary end plate aperture connecting to one end of said loop, and said wall aperture connecting to the other end of said loop.
a casing including (a) a substantially frustoconical casing wall having a base and a narrowed end, said wall tapering directly toward and defining an axial frustrum aperture at said narrowed end and a casing wall aperture at a location between said base and said narrowed end, and (b) a transverse casing end plate at said base of said wall, said end plate defining primary and secondary end plate apertures; and a substantially frustoconical rotor rotatable in said casing having (a) a primary rotor passage which connects said primary end plate aperture to said frustrum aper-ture when said rotor is in a first position and which connects said secondary end plate aperture with said frustrum aperture when said rotor is rotated to a second position, and (b) a secondary rotor passage which connects said primary end plate aperture to said wall aperture when said rotor is in said second position, said primary end plate aperture connecting to one of said instrument pipes, said frustrum aperture connecting to the other of said instrument pipes, said secondary end plate aperture connecting to one end of said loop, and said wall aperture connecting to the other end of said loop.
2. A musical wind instrument comprising:
a lead pipe having a mouthpiece at one end thereof;
a main bore terminating in an instrument bell;
a slide loop;
a casing having (a) first and second opposite ends, and (b) a casing wall extending between said opposite ends, said lead pipe being connected to said casing at said first end, said main bore being connected to said casing at said second end, one end of said loop being connected to said casing at one of said opposite ends, and the other end of said loop being connected to said casing between said ends at said casing wall, said wall having an interior contact face comprising at least one area defined in a surface of circular cross-section, which surface tapers directly toward the region where one of said lead pipe and said main bore connect to said casing; and a rotor rotatable in said casing having (a) an exterior contact face mating with said interior contact face for rotational movement therealong, (b) a primary rotor passage which directly con-nects said lead pipe to said main bore when said rotor is in a first position and which connects said one end of said loop to said one of said lead pipe and said main bore when said rotor is rotated to a second position, and (c) a secondary rotor passage which connects the other of said lead pipe and said main bore to said other end of said loop when said rotor is in said second position.
a lead pipe having a mouthpiece at one end thereof;
a main bore terminating in an instrument bell;
a slide loop;
a casing having (a) first and second opposite ends, and (b) a casing wall extending between said opposite ends, said lead pipe being connected to said casing at said first end, said main bore being connected to said casing at said second end, one end of said loop being connected to said casing at one of said opposite ends, and the other end of said loop being connected to said casing between said ends at said casing wall, said wall having an interior contact face comprising at least one area defined in a surface of circular cross-section, which surface tapers directly toward the region where one of said lead pipe and said main bore connect to said casing; and a rotor rotatable in said casing having (a) an exterior contact face mating with said interior contact face for rotational movement therealong, (b) a primary rotor passage which directly con-nects said lead pipe to said main bore when said rotor is in a first position and which connects said one end of said loop to said one of said lead pipe and said main bore when said rotor is rotated to a second position, and (c) a secondary rotor passage which connects the other of said lead pipe and said main bore to said other end of said loop when said rotor is in said second position.
3. The instrument of claim 2 wherein:
said casing wall includes a right frustoconical por-tion which has a base and a narrowed end and which provides said interior contact face;
said casing includes an end plate which partially covers and yet leaves an opening in said base;
said rotor includes a rotor wall which has a right frustoconical portion providing said exterior contact face, said frustoconical portion being axially-truncated so that said rotor is small enough to pass through said opening; and said instrument further comprises openable door means for retaining said rotor in said casing and maintaining said rotor in axial alignment.
said casing wall includes a right frustoconical por-tion which has a base and a narrowed end and which provides said interior contact face;
said casing includes an end plate which partially covers and yet leaves an opening in said base;
said rotor includes a rotor wall which has a right frustoconical portion providing said exterior contact face, said frustoconical portion being axially-truncated so that said rotor is small enough to pass through said opening; and said instrument further comprises openable door means for retaining said rotor in said casing and maintaining said rotor in axial alignment.
4. The instrument of claim 2 wherein at least a portion of each said contact face is a major arc in a plane perpendicular to the axis of said contact faces.
5. The instrument of claim 2 wherein at least a portion of at least one of said contact faces is a complete circle in cross section.
6. The instrument of claim 4 or 5 wherein said portion is near said narrowed end of said tapered surface.
7. The instrument of claim 2 wherein the faces are defined in identical conical surfaces.
8. The instrument of claim 2 wherein said casing further comprises an end plate at said one of said opposite ends of said casing, said end plate defining apertures which register with said rotor passages when said rotor is in said second position.
9. The instrument of claim 2 wherein:
said casing wall is circular in cross section at said one of said opposite ends;
said casing includes an end plate which covers less than half of said one of said opposite ends, leaving an opening in the casing at said one of said opposite ends; and said rotor is sufficiently small to pass through said opening.
said casing wall is circular in cross section at said one of said opposite ends;
said casing includes an end plate which covers less than half of said one of said opposite ends, leaving an opening in the casing at said one of said opposite ends; and said rotor is sufficiently small to pass through said opening.
10. The instrument of claim 9 further comprising door means to openably cover said opening.
11. A musical wind instrument comprising:
a lead pipe having a mouthpiece at one end thereof;
a main bore terminating in an instrument bell;
a slide loop;
a casing having (a) first and second opposite ends, and (b) a casing wall between said opposite ends, said lead pipe being connected to said casing at said first end, said main bore being connected to said casing at said second end, one end of the loop being connected to said casing at of one of said opposite ends, and the other end of said loop being connected to said casing at said casing wall, said casing wall having an inner surface shaped to provide a rotor seat which tapers directly toward the region where one of said lead pipe and said main bore connects to said casing; and a rotor rotatable in said casing having (a) a tapered outer surface that seats against said inner surface for rotational movement in said casing, (b) a primary rotor passage which directly con-nects said lead pipe to said main bore when said rotor is in a first position and which connects said one end of said loop to said one of said lead pipe and said main bore when said rotor is rotated to a second position, and (c) a secondary rotor passage which connects the other of said lead pipe and said main bore to said other end of said loop when said rotor is in said second position.
a lead pipe having a mouthpiece at one end thereof;
a main bore terminating in an instrument bell;
a slide loop;
a casing having (a) first and second opposite ends, and (b) a casing wall between said opposite ends, said lead pipe being connected to said casing at said first end, said main bore being connected to said casing at said second end, one end of the loop being connected to said casing at of one of said opposite ends, and the other end of said loop being connected to said casing at said casing wall, said casing wall having an inner surface shaped to provide a rotor seat which tapers directly toward the region where one of said lead pipe and said main bore connects to said casing; and a rotor rotatable in said casing having (a) a tapered outer surface that seats against said inner surface for rotational movement in said casing, (b) a primary rotor passage which directly con-nects said lead pipe to said main bore when said rotor is in a first position and which connects said one end of said loop to said one of said lead pipe and said main bore when said rotor is rotated to a second position, and (c) a secondary rotor passage which connects the other of said lead pipe and said main bore to said other end of said loop when said rotor is in said second position.
12. A musical wind instrument comprising:
a lead pipe having a mouthpiece at one end thereof;
a main bore terminating in an instrument bell;
a slide loop;
a casing, said lead pipe, main bore and the ends of said loop being connected to said casing, said casing having a tapered inner surface shaped to provide a rotor seat of arcuate cross section, which surface tapers directly toward the region where one of said lead pipe and said main bore connects to said casing; and a rotor rotatable in said casing having (a) a tapered outer surface that seats against said inner surface for rotational movement in the casing, (b) an axially extending primary rotor passage which directly connects said lead pipe to said main bore when said rotor is in a first position and which connects one end of said loop to said one of said lead pipe and said main bore when said rotor is rotated to a second position, and (c) an axially extending secondary rotor passage which connects the other of said lead pipe and said main bore to the other end of said loop when said rotor is in said second position.
a lead pipe having a mouthpiece at one end thereof;
a main bore terminating in an instrument bell;
a slide loop;
a casing, said lead pipe, main bore and the ends of said loop being connected to said casing, said casing having a tapered inner surface shaped to provide a rotor seat of arcuate cross section, which surface tapers directly toward the region where one of said lead pipe and said main bore connects to said casing; and a rotor rotatable in said casing having (a) a tapered outer surface that seats against said inner surface for rotational movement in the casing, (b) an axially extending primary rotor passage which directly connects said lead pipe to said main bore when said rotor is in a first position and which connects one end of said loop to said one of said lead pipe and said main bore when said rotor is rotated to a second position, and (c) an axially extending secondary rotor passage which connects the other of said lead pipe and said main bore to the other end of said loop when said rotor is in said second position.
13. The instrument of claim 12 wherein at least one of said surfaces extends substantially the entire axial length of said rotor.
14. The instrument of claim 12 wherein:
said casing includes a casing wall having a generally frustoconical portion which provides said tapered inner surface; and an end of said loop is connected to said casing wall.
said casing includes a casing wall having a generally frustoconical portion which provides said tapered inner surface; and an end of said loop is connected to said casing wall.
15. A musical wind instrument having a slide loop, an instrument pipe having a mouthpiece at one end thereof and an instrument pipe terminating in an Instrument bell comprising:
a casing having a rotational axis and two opposed interior contact faces that extend transversely to said axis, at least one of said faces forming a coaxial concave rotor seat, one of said instrument pipes being connected coaxially to said casing at said one of said faces, one end of said loop being connected to said casing at said one of said faces at a distance away from said axis, the other of said instrument pipes and the other end of said loop each being connected to said casing at the other of said faces and each being located an equal distance away from said axis, said one of said faces tapering directly toward the region where said one of said instrument pipes is connected to said casing; and a rotor rotatable about said axis in said casing, said rotor being located between said faces and having opposed exterior contact faces that mate with said interior faces res-pectively for rotational movement therealong, a primary rotor passage which directly connects said one of said instrument pes to said other of said instrument pipes when said rotor is in a first position and which connects said one end of said loop to said one of said instrument pipes when said rotor is rotated to a second position, and a secondary rotor passage which connects said other of said instrument pipes to said other end of said loop when said rotor is in said second position.
a casing having a rotational axis and two opposed interior contact faces that extend transversely to said axis, at least one of said faces forming a coaxial concave rotor seat, one of said instrument pipes being connected coaxially to said casing at said one of said faces, one end of said loop being connected to said casing at said one of said faces at a distance away from said axis, the other of said instrument pipes and the other end of said loop each being connected to said casing at the other of said faces and each being located an equal distance away from said axis, said one of said faces tapering directly toward the region where said one of said instrument pipes is connected to said casing; and a rotor rotatable about said axis in said casing, said rotor being located between said faces and having opposed exterior contact faces that mate with said interior faces res-pectively for rotational movement therealong, a primary rotor passage which directly connects said one of said instrument pes to said other of said instrument pipes when said rotor is in a first position and which connects said one end of said loop to said one of said instrument pipes when said rotor is rotated to a second position, and a secondary rotor passage which connects said other of said instrument pipes to said other end of said loop when said rotor is in said second position.
16. A musical wind instrument comprising:
a lead pipe having a mouthpiece at one end thereof, a main bore terminating in an instrument bell;
a slide loop;
a casing having (a) a casing wall, said wall including a right frustoconical portion having a base and a narrow-ed end, said frustoconical portion defining a casing axial aperture at said narrowed end and a casing wall aperture at a location between said base and said narrowed end, and said wall includ-ing a cylindrical portion extending from said base of said frustoconical portion to a circular casing outer end, said portions having a common axis, (b) a casing end plate having an interior surface which extends normally to said axis, said end plate being secured to said cylindrical portion so that it partially covers an area contained entirely within two adjacent quadrants of said outer end so that said casing wall and said end plate together define an opening in said casing at said outer end, said end plate defining pri-mary and secondary casing end plate apertures spaced an equal distance from said axis, one of said lead pipe and said main bore being connected to said primary end plate aperture, the other of said lead pipe and said main bore being connected to said casing axial aperture, one end of said loop being connected to said secondary end plate aperture, and the other end of said loop being connected to said casing wall aperture; and a rotor dimensional to pass through said opening, said rotor having (a) rotor wall, said wall including a partially right frustoconical portion having a base and a narrowed end, said frustoconical portion defining a rotor axial aperture at said narrowed end and a rotor wall aperture at a location between said base and said narrowed end, said rotor wall also including a right cylindrical portion extending from said base of said frustoconical portion to a rotor outer end, both of said portions being coaxial with said axis, said frustoconical por-tion of said rotor wall being positioned against said right frustoconical portion of said casing wall, and said axial and wall apertures defined by said rotor wall being in alignment with and of substantially the same size and shape as said axial and wall apertures defined by said casing wall, said rotor wall having an axially-truncated edge, (b) an axially extending rotor sidewall mounted on said rotor wall at said truncated edge so that, in cross section through said truncated edge, said rotor comprises a major arc formed by said rotor wall and a secant formed by said side wall;
(c) a rotor end plate covering said rotor outer end and having a flat outer surface positionable against said interior surface of said casing end plate, said rotor end plate defining primary and secondary rotor end plate apertures in alignment with and of substantially the same size and shape as said secondary and primary casing end plate apertures, (d) a primary rotor tube extending between said rotor axial aperture and said primary rotor end plate aperture, (e) a secondary rotor tube extending between said rotor wall aperture and said secondary rotor end plate aperture, (f) a shaft fixed on said rotor end plate, said shaft being coaxially aligned with said axis whereby said rotor is rotatable in said casing about said axis between a first position wherein said primary rotor end plate aperture registers with said primary end plate aperture and a second position wherein each of said rotor apertures registers with a casing aperture; and a door for at least partially covering said opening to retain said rotor in said casing, said door being removably secured to said casing so that it can be opened for removal of said rotor, at least one of said casing end plate and said door having shaft retaining means for maintaining said shaft in axial alignment when said door is closed.
a lead pipe having a mouthpiece at one end thereof, a main bore terminating in an instrument bell;
a slide loop;
a casing having (a) a casing wall, said wall including a right frustoconical portion having a base and a narrow-ed end, said frustoconical portion defining a casing axial aperture at said narrowed end and a casing wall aperture at a location between said base and said narrowed end, and said wall includ-ing a cylindrical portion extending from said base of said frustoconical portion to a circular casing outer end, said portions having a common axis, (b) a casing end plate having an interior surface which extends normally to said axis, said end plate being secured to said cylindrical portion so that it partially covers an area contained entirely within two adjacent quadrants of said outer end so that said casing wall and said end plate together define an opening in said casing at said outer end, said end plate defining pri-mary and secondary casing end plate apertures spaced an equal distance from said axis, one of said lead pipe and said main bore being connected to said primary end plate aperture, the other of said lead pipe and said main bore being connected to said casing axial aperture, one end of said loop being connected to said secondary end plate aperture, and the other end of said loop being connected to said casing wall aperture; and a rotor dimensional to pass through said opening, said rotor having (a) rotor wall, said wall including a partially right frustoconical portion having a base and a narrowed end, said frustoconical portion defining a rotor axial aperture at said narrowed end and a rotor wall aperture at a location between said base and said narrowed end, said rotor wall also including a right cylindrical portion extending from said base of said frustoconical portion to a rotor outer end, both of said portions being coaxial with said axis, said frustoconical por-tion of said rotor wall being positioned against said right frustoconical portion of said casing wall, and said axial and wall apertures defined by said rotor wall being in alignment with and of substantially the same size and shape as said axial and wall apertures defined by said casing wall, said rotor wall having an axially-truncated edge, (b) an axially extending rotor sidewall mounted on said rotor wall at said truncated edge so that, in cross section through said truncated edge, said rotor comprises a major arc formed by said rotor wall and a secant formed by said side wall;
(c) a rotor end plate covering said rotor outer end and having a flat outer surface positionable against said interior surface of said casing end plate, said rotor end plate defining primary and secondary rotor end plate apertures in alignment with and of substantially the same size and shape as said secondary and primary casing end plate apertures, (d) a primary rotor tube extending between said rotor axial aperture and said primary rotor end plate aperture, (e) a secondary rotor tube extending between said rotor wall aperture and said secondary rotor end plate aperture, (f) a shaft fixed on said rotor end plate, said shaft being coaxially aligned with said axis whereby said rotor is rotatable in said casing about said axis between a first position wherein said primary rotor end plate aperture registers with said primary end plate aperture and a second position wherein each of said rotor apertures registers with a casing aperture; and a door for at least partially covering said opening to retain said rotor in said casing, said door being removably secured to said casing so that it can be opened for removal of said rotor, at least one of said casing end plate and said door having shaft retaining means for maintaining said shaft in axial alignment when said door is closed.
17. The instrument of claim 16 where said door defines a shaft aperture to receive and journal said shaft.
18. The valve of claim 1 for a musical wind instru-ment having a secondary slide loop, a secondary instrument pipe in a sound path connectable with the mouthpiece, and a secon-dary instrument pipe connectable with said bell, where;
said casing wall defines secondary and tertiary casing wall apertures at locations between said base and said narrowed end;
said casing end plate defines tertiary and quatenary end plate apertures;
said rotor further has (a) a tertiary rotor passage which connects said tertiary rotor end plate apertures to said secon-dary casing wall aperture when said rotor is in said first position and which connects said tertiary rotor end plate aperture to said tertiary casing wall aperture when said rotor is in said second position, and (b) a quatenary rotor passage which connects said quatenary casing end plate aperture to said secondary casing wall aperture when said rotor is in said second position, said tertiary end plate aperture connecting to one of said secondary instrument pipes, said secondary casing wall aperture connecting to the other of said secondary instrument pipes, said quantenary end plate aperture connecting to one end of said secondary slide loop, and said tertiary casing wall aperture connecting to the other end of said secondary slide loop.
said casing wall defines secondary and tertiary casing wall apertures at locations between said base and said narrowed end;
said casing end plate defines tertiary and quatenary end plate apertures;
said rotor further has (a) a tertiary rotor passage which connects said tertiary rotor end plate apertures to said secon-dary casing wall aperture when said rotor is in said first position and which connects said tertiary rotor end plate aperture to said tertiary casing wall aperture when said rotor is in said second position, and (b) a quatenary rotor passage which connects said quatenary casing end plate aperture to said secondary casing wall aperture when said rotor is in said second position, said tertiary end plate aperture connecting to one of said secondary instrument pipes, said secondary casing wall aperture connecting to the other of said secondary instrument pipes, said quantenary end plate aperture connecting to one end of said secondary slide loop, and said tertiary casing wall aperture connecting to the other end of said secondary slide loop.
19. The valve of claim 1 wherein:
said primary rotor passage is straight; and at their junctions with said valve, said instrument pipes are axially aligned such that when said rotor is in said first position, there is a straight sound path between the interiors of said instrument pipes.
said primary rotor passage is straight; and at their junctions with said valve, said instrument pipes are axially aligned such that when said rotor is in said first position, there is a straight sound path between the interiors of said instrument pipes.
20. The instrument of claim 2 or 12 wherein said casing further includes:
a right frustoconical portion which has a base and a narrowed end and which provides said interior contact face, said base being externally threaded, an end plate which covers said base to retain said rotor in the casing and which defines a journal opening to maintain said rotor in axial alignment; and a retainer ring which is internally threaded to mate with said base and hold said end plate in position.
a right frustoconical portion which has a base and a narrowed end and which provides said interior contact face, said base being externally threaded, an end plate which covers said base to retain said rotor in the casing and which defines a journal opening to maintain said rotor in axial alignment; and a retainer ring which is internally threaded to mate with said base and hold said end plate in position.
21. The musical instrument of claim 2 or 12 comprising multiple valve assemblies arranged in a series, each including one said casing and one rotor wherein said primary rotor passage is straight, said assemblies being aligned along a common axis such that when each of said rotors is in said first position there is a straight sound path extending through all the valve assemblies in said series.
22. The musical instrument of claim 2 or 12 comprising multiple valve assemblies arranged in a series, each including one said casing and one rotor wherein said primary rotor passage is straight, said assemblies being aligned along a common axis, said lead pipe connecting to the first valve assembly in said series and said main bore connecting to the last valve assembly in said series, at their junctions with said first and last valve assemblies, said lead pipe and said main bore being axially aligned with said common axis such that when each of said rotors is in said first position, there is a straight sound path extending from within said lead pipe into said main bore.
23. A rotary valve for a musical wind instrument having a slide loop, an instrument pipe with a mouthpiece at one end and an instrument pipe terminating in an instrument bell, said valve comprising:
a casing including (a) a substantially frustoconical casing wall having a base and a narrowed end, said wall defining two casing wall apertures, each at a location between said base and said narrowed end, and (b) a transverse casing end plate at said base of said wall, said end plate defining two end plate apertures; and a substantially frustoconical rotor rotatable in said casing having (a) a rotor passage which connects said one of said end plate apertures to one of said casing wall apertures when said rotor is in a first position and which connects said one of said end plate apertures with the other of said casing wall apertures when said rotor is rotated to a second position, and (b) a rotor passage which connects said other of said end plate apertures to said one of said casing wall apertures when said rotor is in said second position, said one of said end plate apertures connecting to one of said instrument pipes, said one of said casing wall apertures connecting to the other of said instrument pipes, said other of said end plate apertures connecting to one end of said loop, and said other of said casing wall apertures connecting to the other end of said loop.
a casing including (a) a substantially frustoconical casing wall having a base and a narrowed end, said wall defining two casing wall apertures, each at a location between said base and said narrowed end, and (b) a transverse casing end plate at said base of said wall, said end plate defining two end plate apertures; and a substantially frustoconical rotor rotatable in said casing having (a) a rotor passage which connects said one of said end plate apertures to one of said casing wall apertures when said rotor is in a first position and which connects said one of said end plate apertures with the other of said casing wall apertures when said rotor is rotated to a second position, and (b) a rotor passage which connects said other of said end plate apertures to said one of said casing wall apertures when said rotor is in said second position, said one of said end plate apertures connecting to one of said instrument pipes, said one of said casing wall apertures connecting to the other of said instrument pipes, said other of said end plate apertures connecting to one end of said loop, and said other of said casing wall apertures connecting to the other end of said loop.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000455598A CA1210971A (en) | 1984-05-31 | 1984-05-31 | Axial flow valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000455598A CA1210971A (en) | 1984-05-31 | 1984-05-31 | Axial flow valve |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1210971A true CA1210971A (en) | 1986-09-09 |
Family
ID=4127982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000455598A Expired CA1210971A (en) | 1984-05-31 | 1984-05-31 | Axial flow valve |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1210971A (en) |
-
1984
- 1984-05-31 CA CA000455598A patent/CA1210971A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |