GB2209087A - Valve assembly for a musical instrument - Google Patents

Abstract

A valve assembly for a musical instrument comprises a plurality of coaxial valve chambers (13, 23, 33) each of circular cross-section and provided with a plurality of ports (44) through which air may flow to or from the respective chamber. Valve barrels (15, 25, 35) are mounted for rotation through a restricted angle between end positions about the axis of the chambers each in a corresponding one of the chambers (13, 23, 33) with an outer surface in sliding sealing engagement with the chamber inner surface. Each barrel has a plurality of passages (56) disposed to interconnect certain ports (44) when the barrel is in the first end position and to interconnect different ports (44) when the barrel is in the second end position. The barrels are rotated between the end positions by keys (19, 29, 39) adjustably mounted on sleeves (17, 27), and shaft (37), respectively. The arrangement is compact and allows ready adjustment of the spacing between the keys (19, 29, 39). The outer surface of each barrel and the inner surface of each chamber may be frustoconical. <IMAGE>

Description

VALVE ASSEMBLY FOR A MUSICAL INSTRUMENT This invention relates to a valve assembly for a musical instrument, and especially to a valve assembly for brass wind instruments, for example comets, euphoniums and the like.

Various valve assemblies have been proposed for brass wind instruments in the past, including so-called "piston" valves and rotary valves. In a rotary valve system a plurality of casings of circular cross-section are mounted with their axes parallel, each casing having a rotary barrel mounted therein for rotation about the axis of its casing between two positions in one of which certain of the valve ports are interconnected whereby to provide a flow path through certain tubing of the instrument and a further position in which different ports are inter-connected whereby to change the flow path of air through the instrument.These known rotary valves are operated by cranked levers connected to a projecting shaft of the valve barrel whereby to rotate the valve barrel between the two operative positions: whilst these known valves function reasonably satisfactorily, the operating linkage is somewhat complex and occupies an undesirable amount of space and is prone to wear on the linkages.

In one aspect the present invention provides a valve assembly for a musical instrument comprising a plurality of coaxial valve chambers, each of circular cross-section and each being provided with a plurality of ports through which air may be admitted to or conducted from the chamber, a plurality of valve barrels, each mounted for rotation through a restricted angle between first and second end positions about the axis of the chambers in a corresponding one of the chambers with an outer surface thereof in sliding sealing engagement with an inner surface of the chamber, each barrel comprising a plurality of passageways disposed to interconnect certain ports of the chamber when the barrel is in the first end position and to interconnect different ports when the barrel is in the second end position.This plurality of valve barrels have operating means for rotating the barrels relative to their respective casings. The operating means preferably comprise a shaft mounted for rotation about the axis of the chambers and a plurality of sleeves a first of which is mounted for rotation on the shaft, each successive sleeve being mounted for rotation on the preceding sleeve, the shaft being secured near a first end portion to a first barrel, the first sleeve being secured near a first end portion to a second barrel adjacent the first and each succeeding sleeve being secured near a first end portion to the barrel remote from the first barrel adjacent the barrel to which the preceding sleeve is secured, second end portions of the shaft and sleeves projecting for connection of drive means to the shaft and each sleeve whereby operation of one of the drive means rotates the associated shaft or sleeve to rotate the barrel secured thereto between its first and second end positions.

Preferably the chambers are provided in a single casing and each barrel has small radial bearing faces, the bearing faces of adjacent barrels bearing on one another and bearing faces of the two end barrels bearing on faces of end caps of the casing whereby to locate each barrel in its corresponding chamber.

Preferably the first barrel is of smaller diameter than the second barrel, the diameter of each successive barrel being longer than the preceding barrel and the chambers are of corresponding diameter, the casing (where they are formed in a single casing) being stepped.

Alternatively the outer surface of each barrel may be slightly frustoconical as may the cooperating inner surfaces of the corresponding chambers which may facilitate sealing contact of the barrels and casing, axial adjustment of the barrels adjusting the sealing contact.

Preferably the shaft projects from the casing providing the chambers a greater distance than any of the sleeves, and each successive sleeve projects a smaller distance than the immediately preceding sleeve whereby to facilitate connection of the drive means. Conveniently each drive means comprises a key connected to the appropriate one of the shaft or sleeves operable by a player to rotate the associated barrel from the first end position to the second end position against the action of spring means, e.g. a tension spring, by which the barrel is urged towards the first end position when the key is released. Those keys may be positioned along the shaft and sleeves to give a lateral distance between the keys most appropriate to the size of the hand of the player.

Preferably the valve assembly comprises adjustable stop means by which the end positions may be adjusted.

Conveniently, the adjustable stop means for each valve comprises projecting means which projects into a groove in the barrel, the projecting means engaging the ends of the groove to limit rotation of the barrel and the positon of the projecting means being adjustable to adjust the first and second end positions.

Valve assemblies in accordance with the invention may also be used to provide so-called "compensation" valves, where the active port interconnections differ depending on whether only one valve has been operated or more than one valve has been operated simultaneously.

There now follows a detailed description, to be read with reference to the accompanying drawings of a musical instrument, namely a cornet, showing a valve assembly embodying the invention. It will be realised that this cornet has been selected for description to illustrate the invention by way of example.

In the accompanying drawings: Figure 1 is a perspective view showing the illustrative cornet with certain parts not shown; Figure 2 is a view in longitudinal section of the valve assembly of the illustrative cornet; Figure 3 is a view in section on the line A-A of Figure 2; Figure 4 is a view on the line B-B of Figure 2; Figure 5 is a view in section on the line C-C of Figure 2; and Figure 6 is a view in the direction of the arrow D of Figure 2.

The illustrative cornet is, in many respects similar to cornets of known construction except that it comprises a valve assembly 40 embodying the invention. The valve assembly 40 comprises three valves 11, 21, 31 provided in a casing 41 of the valve assembly. The casing 41 has a plurality of coaxial valve chambers 13, 23, 33, of the valves 11, 21, 31 respectively. Each of the valve chambers 13, 23, 33 is of circular cross-section and provided with a plurality of ports through which air may be admitted or conducted from the associated one of the chambers. The valve assembly further comprises a plurality of valve barrels 15, 25, 35 mounted, respectively, in the chambers 13, 23, 33 for rotation through a restricted angle between first and second end positions about the axis X of the chambers 13, 23, 33.

Each of the barrels 15, 25, 35 is mounted in a corresponding one of the chambers 13, 23, 33 with an outer surface thereof in sliding, sealing engagement with an inner surface of the chamber. Each barrel 15, 25, 35 comprises a plurality of passages 46 disposed to interconnect certain ports 44 of the appropriate one of the chambers 13, 23, 33 when the barrel is in the first end position and to interconnect different ports when the barrel is in the second end position.

In the drawings the barrels 15, 25, 35 are shown in the first position with the passages 46 shown in full line. The position occupied by the passages 46 when the barrel 15, 25, 35 are in the second position are indicated by dash lines in the drawings.

The casing 41 comprises, at a first end, an end cap 48 and, at the second end, an end cap 49, the end caps being secured by screw threads.

The valve assembly of the illustrative cornet further comprises operating means including a shaft 37 which extends through the valve assembly and one end portion of which is mounted for rotation in a bearing opening in the end cap 48. The shaft projects through the other end cap 49. The shaft 37 is secured to the barrel 35 so that rotation of the shaft 37 is effective to likewise rotate the barrel 35. As can be seen from Figure 2 each of the barrels 15, 25, 35 has radial bearing faces 42. The bearing faces 42 of adjacent ones of the barrels 15, 25, 35 are arranged to bear on one another and bearing faces of the two end barrels 15, 35 also bear on faces of the adjacent end caps 49, 48 respectively whereby to locate each barrel in its corresponding chamber.

In Figure 2 the casing 41 is of stepped configuration and the chamber 33 is of smaller diameter than the chamber 23, the chamber 23 likewise being of smaller diameter than the chamber 13. An alternative (not shown) casing construction may, if desired, be adopted.

In this alternative construction, otherwise generally similar to that shown in Figure 2, the casing is frustoconical internally so that each chamber is frustoconical. Whereas the outer surfaces of the barrels 15, 25, 35 shown in Figure 2 of the drawings are cylindrical, the outer surfaces of the barrels of the alternative valve assembly are frustoconical, complementary with the internal surface of the casing. By adjustment of the axial position of each barrel in the casing of the alternative valve assembly the fit of the barrels within the casing can be made tighter or looser thereby adjusting the sealing capacity of each barrel: the tightness of each barrel in the casing has to be selected so that each barrel will rotate freely in its appropriate chamber while yet providing a sufficient seal preventing leakage of air round the barrels between the barrels and the casing.Axial adjustment of the barrels thus adjusts the sealing contact between the barrels and casing.

The smaller valve barrel 35 is secured to a shaft 37 so that the rotation of the shaft 37 is effective to rotate the barrel 35 relative to chamber 33.

A first sleeve 27 which is shorter than shaft 37 is mounted for rotation on shaft 37 with one end of sleeve 27 adjacent to barrel 35 which is mounted on shaft 37.

The middle sized barrel 25 is secured to sleeve 27 so that the rotation of sleeve 27 is effective to rotate the barrel 25 relative to chamber 23.

The valve assembly also comprises a second sleeve 17 which is shorter than sleeve 27. Sleeve 17 is mounted for rotation on sleeve 27 with one end of sleeve 17 adjacent to barrel 25 which is mounted on sleeve 27.

The larger valve barrel 15 is secured to sleeve 17 so that rotation of sleeve 17 is effective to rotate the barrel 15 relative to chamber 13.

The combination of shaft 37 and sleeves 27 and 17 project through and are supported by end cap 49. Sleeve 17 projects beyond end cap 49 a sufficient distance for finger key 19 to be fitted and also leaving room for lateral adjustment. Sleeve 27 projects beyond sleeve 17 a sufficicent distance for finger key 29 to be fitted and also leaving room for lateral adjustment. Shaft 37 projects beyond sleeve 27 a sufficient distance for finger key 39 to be fitted and also leaving room for lateral adjustment.

The keys, 19, 29, 39 provide drive means for the valve. barrels and, as can be seen from Figure 1, are positioned in a position to be operated by the player of the instrument, in substantially the same positions relative to the mouth pipe 50 of the instrument as the valves would occupy in a conventional cornet, so that the playing position of the illustrative cornet is similar to that of a conventional instrument.

The distance by which the shaft 37 and sleeves 17, 27 project is sufficient to ensure that the spacing of the keys 19, 29, 39 attached to each of the shaft 37, and sleeves 17, 27, can be adjusted lengthwise of the axis of rotation so as to be suitably spaced for convenient operation by the player, dependent upon the hand size of the player.

As in a conventional instrument the valves are operated by the player pressing the keys 19, 29, 39 whereby to rotate the barrel 15, 25, 35 of the appropriate one of the valves 11, 21, 31 from its first position to its second position. The barrels are each returned to the second position, after the appropriate key 19, 29, 39 has been released, by a spring 52 extending between a lug on the key and a fixed lug 54 which may conveniently be mounted on a stay (not shown) of the instrument. Conveniently the tension of each spring 52 may be adjusted, suitably by means of a pair of adjusting nuts 56 by which an adjusting screw to which the spring 52 is attached may be positioned relative to the lug 54.

The valve assembly further comprises adjustable stop means by which the first and second end positions may be adjusted. One of these adjustable stop means is shown on the valve 31 in Figure 3 of the drawings and comprises an arcuate groove 58 cut in the outer surface of the barrel 35 and a stop member which is received in the groove 58.

The stop member comprises a cam stop 60 attached to the end portion of a screw member 62 received in the casing 41. The screw member 62 may be rotated relative to the casing 41 whereby to rotate the eccentric cam stop 60 thereby to adjust the position of the barrel 35 relative to the casing 41 when the end portion of the groove engages the cam stop 60. The screw member 62 may conveniently be locked in position after it has been adjusted by lock nuts 64. The adjustable stop means shown in Figure 3 is adjusted to define the first end position of the barrel 35. To define the second end position of the barrel 35 a similar cam stop (not shown) may be arranged in the same groove 58 or a second groove may suitably be provided.Alternatively, the configuration of the cam stop 60 may be such that by adjusting the stop 60 to appropriately define the first end position, the second end position is also defined, engagement of the opposite end portion of the groove 58 with the cam stop 60 defining this second end position. Other adjustable stop means may suitably be provided if desired, for example the arc of rotation of the keys 48 may be restricted by engagement with suitable buffers mounted on fixed portions of the instrument.

The ports 44 of the illustrative cornet suitably open into pipes 65 by which the air is conducted through the instrument, in conventional manner. Only two of the pipes 65 are shown in Figure 1 for clarity; it would of course be necessary to provide piping of suitable lengths for each valve 11, 21, 31 so that the valves make the appropriate changes to the overall lengths of the tubing through which air is passing.By operation of the appropriate key 19 to move barrel 15 between the first and second end positions, the pitch of the instrument will be lowered by one tone, by operation of the key 29 to rotate the barrel 25 from its first end position to its second end position the pitch of the instrument will be lowered by a half tone, while by operation of the appropriate key 39 to rotate the barrel 35 from its first to its second end position the pitch of the instrument will be lowered one and a half tones. Suitable tubing will also be provided to conduct the air flow from one valve to the next of the valve assembly so that air introduced into the instrument through the mouth pipe 50 by the player will leave the instrument at the bell 66.

None of the valve slides nor the interconnecting tubing is shown, for clarity. Likewise none of the stays by which the various slides and tubing are usually supported in a musical instrument are shown. In order to stabilise the valve assembly 40, a suitable stay may be provided having a bearing member supporting the shaft 37 at the end projecting beyond the end cap 38; likewise, if desired, further bearing members may be provided to support the projecting end portions of the sleeves 17, 27.

Although, in the illustrative cornet, the mouth pipe 50 is introduced to the valve assembly at the valve 11 closest to the bell 66, and the pipe 65 leading to the bell 66 leaves the valve assembly at the valve 31, closest to the lips of the player, the position at which the mouth pipe 50 enters the valve assembly and that at which the bell pipe leaves the valve assembly may be exchanged, that is the mouth pipe may enter the valve assembly at the valve 31 and the bell pipe may leave the valve assembly at the valve 11. However, this latter arrangement is not preferred because the two pipes in the latter arrangement will cross one another leading to additional complexity in manufacture.

In the manufacture of the illustrative cornet, conventional manufacturing techniques are used and apart from the novel valve assembly, the remainder of the instrument is substantially conventional in design. Of course, the detailed layout of the various pipes, ports in the valves 11, 21, 31 and passages in the barrels 15, 25, 35 will be adjusted by the instrument manufacturer as appropriate to achieve the desired configuration of instrument.

Although the detailed description is of a cornet, it will be appreciated that similar valve assemblies may be used in other brass musical instruments, for example euphoniums, tenor horns, basses, trumpets, french horns and the like.

In the illustrative instrument the rotation of the valve barrels 15, 25, 35 between the first and second end 0 positions is through an angle of 30 . By appropriate design of the instrument, the actual degree of rotation between the first and second end positions may be adjusted, bearing in mind that it will be necessary of course, to ensure that the passages 46 through the valves do not have unacceptably sharp curves nor lead to valve sections with insufficient metal to provide adequate support - for example, the valves may be arranged to rotate through 450, 600 or less than 300 e.g. 22 o between the first and second end positions. Although the provision of a direct acting drive means is preferred in the interests of simplicity of manufacture and compactness, it would of course be possible in a valve assembly otherwise similar to the valve assembly shown in the drawings to operate the valves through a suitable linkage.

Claims (11)

1. A valve assembly for a musical instrument comprising a plurality of coaxial valve chambers, each of circular crossection and each being provided with a plurality of ports through which air may be admitted to or conducted from the chamber, a plurality of valve barrels in a corresponding one of the chambers, each mounted for rotation through a restricted angle between first and second end positions about the axis of the chambers with an outer surface thereof in sliding sealing engagement with an inner surface of the chamber, each barrel comprising a plurality of passageways disposed to interconnect certain ports of the chamber when the barrel is in the first end position and to interconnect different ports. when the barrel is in the second end position.

2. A valve assembly according to Claim 1 comprising operating means including a shaft mounted for rotation about the axis of the chambers and a plurality of sleeves a first of which is mounted for rotation on the shaft and each successive sleeve being mounted for rotation on the preceding sleeve, the shaft being secured near a first end portion to a first barrel, the first sleeve being secured near a first end portion to a second barrel adjacent the first and each succeeding sleeve being secured near a first end portion to the barrel remote from the first barrel adjacent the barrel to which the preceding sleeve is secured, second end portions of the shaft and sleeves projecting for connection of drive means to the shaft and each sleeve whereby operation of one of the drive means rotates the associated shaft or sleeve to rotate the barrel secured thereto between its first and second end positions.

3. A valve assembly according to Claim 2 wherein the shaft projects from the casing providing the chambers a greater distance than any of the sleeves, each successive sleeve projecting a smaller distance than the immediately preceding sleeve whereby to facilitate connection of the drive means.

4. A valve assembly according to Claim 3 wherein each drive means comprises a key connected to the appropriate one of the shaft or sleeves, operable by a player to rotate the associated barrel from the first end position to the second end position against the action of spring means by which the barrel is. urged towards the first end position when the key is released.

5. A valve assembly according to Claim 4 wherein the position of the keys along the shaft and sleeves may be adjusted thus to adjust the lateral distance between the keys.

6. A valve assembly according to any one of the preceding claims wherein the chambers are provided in a single casing and each barrel has radial bearing faces, the bearing faces of adjacent barrels bearing on one another and bearing faces of the two end barrels bearing on faces of end caps of the casing whereby to locate each barrel in its corresponding chamber.

7. A valve assembly according to any one of the preceding claims wherein the first barrel is of smaller diameter than the second barrel, the diameter of each successive barrel being greater than that of the preceding barrel and wherein the chambers are of corresponding diameter, the casing (where the chambers are formed in a single casing being stepped.

8. A valve assembly according to any one of Claims 1 to 6 wherein the outer surface of each barrel is frustoconical as are the cooperating inner surfaces of the corresponding chambers.

9. A valve assembly according to any one of the preceding claims comprising adjustable stop means by which the end positions. may be adjusted.

10. A valve assembly according to Claim 9 wherein the adjustable stop means for each valve comprises projecting means which project into a groove in the barrel, the projecting means engaging the ends of the groove to limit rotation of the barrel and the position of the projecting means being adjustable to adjust the first and second end positions.

11. A valve assembly for a musical instrument constructed arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.