US1025795A - Expression mechanism for self-playing musical instruments. - Google Patents

Description

O. J; FAI RGHILD. EXPRESSION MECHANISM FOR SELF PLAYING MUSICAL INSTRUMENTS.

APPLICATION FILED JULY 6,1908. Y 1,025,795. I Patented May 7, 1912.

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APPLICATION FILED JULY6,19OB. 1,025,795. Patented May 7, 1912.

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O. J. PAIRGHILD. ANISM FOR SELF PLAYING MUSICAL INSTRUMENTS.

APPLICATION FILED JULZ6,1908.'

EXPRESSION MESH 1 ,025,795.'

0. J. FAIRGHILD. EXPRESSION MECHANISM FOR SELF PLAYING MUSICAL INSTRUMENTS.

- APPLIOATION FILED JULY 6,1908 1,025,795.

Patented May 7, 1912.

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se mowmw a f I UNITED sTA'rns Parana? or OREN' J. FAIRCHILD, 0F BINGHAMTON, NEW YORK, ASSIGN'OR 0F GEE-HALF TO WILLIAM J. PAYNE, 0F CANDOR, NEW YORK.

EXPRESSION MECHANISM FOR SELFJPLAYING MUSICAL INSTRUMENTS.

Specification of Letters "Eatent.

Patented May *7, 1912.

Application tiled July 43, 1908. Serial No. 442,072.

To all whom it may concern:

Be itknown that I, OREN J. FAIRCHILD, a citizen of the United States, residing, at Binghamton, in the county of Broome and State of New York, have invented certain new and useful Improvements in Expression Mechanism for Self-Playing Musical Instrmnents, of which the following is a specification, reference being had to the drawings acconmanying and forming part of the same.

My invention relates toself-playing musi cal instruments, for example pianos, of the soralled pneumatic typeth atis, in-

struments operated by pneumatic pressure in which the playing instrumentalities are under the control of a perforated sheetor band of, generally, the usual kind.

The chief object of the invention, briefly stated, is to provide mechanism forputting into the musical composition as played, what is commonly called expression,in other words to provide mechanism, under the control of the perforated tune sheet, for varying the loudness of the sound so as to make the music more effective or pleasing and to bring out, in a measure at least, the musical idea which a. musical composition is supposedly intended to express.

Heretofore various means have been devised, and used with satisfactory results, for put-ting the expression under the control of the operator, who by the manipulation of suitable controlling devices can vary the loudness of the playing to suit his individual fancy. So far as I am aware, however, no thoroughly satisfactory means have been proposed for varying the expression under the control of the tune-sheet; and this in spite of the fact that musical instruments, for example self-playing pianos, have been on the market for a considerable period, in which all the functions-of the instrument are under the control of the tune-sheet without any attention on the part of an operator except merely to insert the sheet and start the motor. My present invention there-fore contemplates the provision of expression mechanism for the purpose referred to,

which shall be thoroughly effective and reliable in operation and result, and as simple and inexpensive as the nature of the case will permit.

In carrying out my invention in the preferred manner I provide a bellows or equivalent device, which from its purpose and function may be appropriately termed the fexpression bellows. This bellows is connected both to theair pump and to the socalled wind chest or vacuum chamber, whichlatter is operatively connected with the playing pneun'iatics. Being thus connected with the vacuum chamber-it is clear that any expansion of the bellows without the admission of air. thereto will have the effectof increasing the vacuum in the vacuum chamber, causing the playing pneumat-ics to be acted on more powerfully by the atmospheric pressure and hence causing harder blows to be struck on the strings and corresponding louder sounds to be produced. On the other hand, it is equally effect will be to decrease the vacuum in the vacuum chamber and so result in softer playing; while if the valve be kept closed, so that. the pump can withdraw air from the expression bellows and vacuum chamber to a greater extent than the normal, the

loudness of the playing will be increased so long as the valve is kept in that condition. Thus by the expansion of the bellows without the admission of air thereinto or into the bellows-vacuum-chamber system I provide for so-called acccnting, that is, for a quick and pronounced but temporary increase in the loudness of the note or notes: while by the control of the expression bellows valve I provide for a more sustained increase or decrease of loudness; it being understood of course that in any case the air pump continues to operate at its normal rate. Hence my invention operates to produce expression in the playing of a composition, not by cont-rolling the pump, as

by varying its speed or otherwise, but by varying the degree of vacuum in the vacuum chamber or wind chest through the iustrumentality of a suitable pneumatic device. namely, an expression bellows.

lVith this brief statement ofthe underlying principle of my invention, reference may now be made to the annexed drawings, which exhibit what I consider the best mode of applying that principle; it being understood, in this connection, that the devices illustrated, and now about to be described more or less in detail, constitute merely the "preferred embodiment of the invention.

rious devices associated therewith.

' nectidn with the diaphragm-chambers, the

cording to the the devices device through 'by link 8 valves which control the diaphragms acexpression perforations in the tune-sheet. Fig. 4 is a longitudinal sectional view of the expression bellows and mounted thereon, showing chiefly the air-valve, the diaphragms tor actuating or controlling the same and the operative connection between the phragms and the valve. Fig. 5 is a sec tional view looking downward on line VV of Fig. 4-, showing the construction of the which the expression bellows is pneumatically connected with the airpumpand the vacuum chamber. Fig. (3 is a diagrammatic sectional view showing the operative relation between the expression bellows and the parts pneumatically asso ciated therewith. Fig. 7 is a detail rear view of the accent device for expanding the expression bellows. Fig. 8 is a section on line VHT-VTH of Fig. 7, looking down ward. Fig. 9 is a diagrammatic sectional view of the accent device, showing the operative relation of the parts thereof.

Referring new to Fig. 1, 1 designates the expression bellows, connected by a tube 2 to the air-pump 3 and by a tube 4 to the vacuum chamber 5. l pneumatics are shown diagrammatically at 6, 6, mounted on the vacuum chamber.

7 designates the accent device, connected with the expression bellows to expand the same, and 9 is the motor, driving the pump by a belt 10 which also engages the pulley 11 the accent device to actuate the same. The {tracker or duct-bridge 12 drawn. to a larger scale than the restof the figure, may be located in any convenient and suitable posit-ion. lit is connected to the expression bellows by tubes 13, 14, and to the accent device by a tube 15. The passages or apertures to which these tubes are connected in the duct-bridge are preferably located at one end of the same, as shown, and the corresponding edge of the tune sheet is apple priated to the perforations which coiiperate with such passages, such perforations being arranged in three longitudinal lines, as will be readily understood.

Referring now more particularly to Figs. 1 to 6, inclusive, the expression bellows is removably secured in position on the piano dia-' bellows,

A few of the playing.

the said end in l case by means of its back or base 16, the lower beveled edge of which fits under a bar or strip 17 while the upper end is engaged by a lag-screw 18. In the top 19 of the bellows is an air valve 20, having a stem 21, which latter is guided in its vertical movement by a cover 22 over the aperture in which the valve works. This aperture is in communication with the atmosphere, above the valve, by passages 22 extending laterally to the sides of the bellows-top, as Sl10\ n in Figs. 2 and 4:. The upper end of the stem is engaged by a lever 23, the other end of which is connected to a coil spring 2d carried by a plate 25'on the overhanging arm 25 of a standard 26 arranged alongside of the bellows. The lever 23 being pivot-ally supported between its ends, as at 27, it will be seen that the tendency of the spring is to hpld the valve 20 closed and to expand the and that the tension of the spring can be' varied by screwing it in or out of its supporting plate, thereby varying the force exerted on the valve and the bellows. The hook 28, by which the spring'is connected to the lever, is formed on a strip or bar 29 which is adjustable lengthwise. of the lever under the pivot 27 and under the setscrcw30, so that by adjusting the hook to- .ward or from the pivot the tension on the valve stem can be regulated independently, to a certain extent, of the tension on the bellows. lVhen the hook is properly adjusted the screw'30 is tightened up, thus binding the two sides of the lever firmly on the hook and holding the same securely in position, as will be readily understood.

, The lower end of'the valve stem bears on the end of a lever 31 pivoted at 32 on the underside of the bellows-top and extending toward the hinge end of the bellows. Bearing on the end of the lever 31 adjacent to of the bellows is a stem 33 slidable in the bellows-top and bearing at its .upper end against an airtight movable dia- 1 phragm 3d. The latter 1s arranged in a' space formed partly in the bellows-top and partly in a block 35 secured on the bellows top, and divides. the said space into two' chambers 36, 37, as shown. In the upper side of the block is a third chamber, 38 separated-from chamber 37 by a partition 39 and closed. by a diaphragm 4.0. Slidably mounted in the said partition is. a pin a1, bearing on the diaphragms 34-, 40. It may here be stated that chamber 36 is in constant con1-- munication with the interior of the bellows through a minute aperture or passage 42 in the bellows-top; while chambers .37 and 38 are normally in communication with the atmosphere but .nay, by the means hereinafter described, be wt. in direct'connection with the air pump.

From the foregoing it will be evident that since'thcre is/a partial vacuum in chamber 36, the pressure of the atmosphere, exerted on the top of diaphragm 34, tends to open the valve 20 against the tension of spring vacuum in the bellows is increased to or above,-a predetermined point. Thus the degree of vacuum in the bellows is normally prevented from rising above a certain point-determined by the tension exerted on the valve 20 by the spring 24since the instant such point is reached the diaphragm 34 depresses the pin 33 and raises the valve through the instrumentality of the lever 31. On the other hand, it is equally clear that if the chamber 37 be put' in communication with the pump, so that the pressure in said chamber will be reduced by exhaust-ion of air therefrom, the pressure in the bellows may fall lower than normal without causing the'valve 20 to be opened. So'long as chamber 38 is in communication with the atmosphere the pressure is the same on both sides of diaphragm 40, and hence the latter has no effect on the lever 31 and valve 20; but

if now the chamber 38 be put in communication with the air-pump, the excess of the atmospheric pressure on top of the diaphragm 40 over the lessened pressure in chamber 38 will depress the diaphragm and so raise the valve 20 against the tension of spring 24. It will therefore be clear that (1) diaphragm 34, when both chambers 37 and 38 are in communication with the atmosphere, automatically prevents the pressure in the bellows from falling below a predetermined limit; that (2) when chamber .37 is put in communication with the pump the diaphragm 34 will not open the valve 20 when the pressure in the bellows falls below normal; and that (3) when chamber 38 is put in communication with the pump the diaphragm 40 positively opens the valve 20 and thus causes the pressure in the bellows to stand higher than normal.

The operation of the diaphragms 34 and 40, to vary the loudness of the playing, is placed under the ultimate control of the tune-sheet. For this .purpose a pair of valves 43, 44 are provided in the block 35, shown best in Figs. 3 and 6. Each of these valves comprises four chambers, 45, 46, 47, 48, the last two being separated by a movable air-tight diaphragm 49 carrying a valve disk 50 arranged to cooperate with either of the apertures in partitions 51, 52 between chambers 46 and 47, and 'chambers'45 and 46, respectively. Chambers 47 i are in communication with a passage 53 in the block 35, which passage is connected wit-l1 the pump through a tube 54 in the manner hereinafter described. Chamber 46 of valve 43 is connected to diaphragm chamber 38, and chamber 46 of valve 44 is connected with diaphragm chamber 37, as shown. Both valve chambers48 are connected to the passage 53 through minute apertures or vents 55, and to the duct-bridge or tracker by the tubes 13, 14. Chambers 45 are in communication with the atmosphere through ports 58.

From the foregoing the operation of the valves in controlling the diaphragms 34, 40, will be readily understood. Assume, for example that a perforation inthe tune sheet comes over the duct-bridge passage to which the tube 13 is connected. Since the chamber 48 (of valve 43) is in communication with the pump, a partial vacuum exists above as well as below diaphragm 49 and in consequence the atmospheric pressure on valve disk 50 holds the latter over the aperture in partition 51. But when a perforation in the tune sheet admits air to the chamber 48, the diaphragm 49 is depressed carrying with it disk 50 which thereupon closes the aperture in partition 52.. This cuts off communicationbetween diaphragm chamber 38 and the atmosphere and establishes communication between said chamber and the pump. A partial vacuum is therefore produced in diaphragm chamber 38, with consequent opening of 'the bellows valve 20 as previously described causing the instrument to play softly. It is clear that if the perforation in the tune sheet be small (or short) the tube 13 will be open only momentarily; hence only a relatively small quantity of air will be admitted to the bellows before the valve 20 is closed again on account of the reverse operation of valve 43; with the result that the decrease in the loudness of the playing will be correspondingly slight, and short in duration. On the other hand if a succession of short perforations passes over the ductbridge passage to which tube 1.3 is connected the duration of the soft playing will be correspondingly lengthened. If the perforations in the tune sheet are each longer,

the valve 20 will be open for a longer time at each passage of a perforation over the duct-bridge, more air will be admitted to the bellows at each opening of valve 20, and

hence the playing will be still softer. Bv

a similar operation of valve 44, diaphragm 34 is raised for longer or shorter periods,

thus causing forte or crescendo effects.

Thus by varying the length and number of 5 the expression perforations in the tune sheet various piano, diminuendo, forte, and

crescendo effects may be produced, as will be readily understood. For producing a quick and loud or fortisl3 belt 10, and a fly-wheel or disk air-tight simo Iefiect in'the playing, the device illustrated more clearly in Figs. 7, 8 and 9 is provided, which will now be described. Mounted in suitable bearings 59, 60, between the air pump and theinotor (see Fig. 1) is a shaft 61 on which are rigidly mounted the driving pulley 11, in engagement with 63. Adjacent to the flat sides of the wheel but normally spaced therefrom by springs '63, are two disks or plates 64:, 65, o f stiff sheet metal, connected at their edges by aflexible band 66 of leather or other suitable material, to form-an air tight casing inclosing the fly-wheel, the said disks 64, 65 being mounted on the shaft 61 to permit rotation thereof without movement of the disks or admission of air into the casing.

One of the disks, as 6-1, is connected by the ink 8 (see Fig. 1) to the expression bellows 1. It will now is exhausted from the wheel casing the external atmospheric pressure will press the disks into firm frictional-contact with the wheel, causing the disks to move with the wheel and, through the instrumentali ty of link 8, quickly expanding the expression bellows without opening the valve 20. The result, as previously described, is to greatly increasethc vacuum in the bellows and vacuum chamber and hence cause the play ing pneumatics to operate with correspondingly greater force. This operation of the wheel casing is effected under the control of devices now to be described.

Mounted loosely on the shaft 61, adjacentto the disk (35, is a block 67, provided with a chamber 68 aroundthe shaft and in communication with the interior of the wheel casing through one or more apertures 69. The clian'iber (38 is also in communication through a passage 70 with separated "from a second ch mber 72 by a. movable air-tight diaphragm 73. The other wall of the chamber 72 has a small diaphragm 74: connected toa lever 75' which carries ,at its free end a valve-disk or cover 76to cooperate with an opening 77.1nto

the passage 70. The block 67 also carries a valve pneumatic 78 (Figs. 7 and 9). comprising three chambers, 79, 80, 81. The first-79 of these chambers is connected to chaniber 72 by a passage 82;-the second 80 is connected to the pump "by the tube 82*, and through a minute aperture or vent 83 to a passage 84: which is in turn connected to the duct-bridge through the tube '15, (Figs. 1 and 7) and the third chamber 81, the outer wall of which is formed by a diaphragm 85, is connected to the passage 84 as shown. The walls of chamber 79 are provided with central openings with which a valve disk 86 cooperates, said valve having a stem 87 bearing on diaphragm 85.

The operation of the mechanism above:

be evident that if the air a chamber 71 described will now be readily understood. Since chambers 79, 80 and 81 are in communication with the pumps, it is evident that so long as the passage 84 is kept closed at the duct bridge the same degree of vacuum will exist in all three chambers and hence atmospheric pressure on diaphragm 85 will hold the disk 86 in the position shown in Fig. cation between chamber 7 2 and the pump through chamber 80 and tube 82*. ,It' now 9, opening communian aperture in the tune-sheet opens passage 84, air will be admitted into chamber 81 faster than it can escape through veut83 to the pump. This relieves the vacuum in 81,

with the result that the valve 86 is reversed, V as will be readily understood, closing coihmunication between chambers 79 and 80 and opening passage 82 to the air. This permits the spring 88 to press diaphragm 7 3 toward the opposite wall of chamber 71, the air escaping from 71 through passage 70 and aperture 77 into the atmosphere. This movement of the diaphragm continues until the limit of its movement is reached, or until closed if that the duct-bridge passage is occurs before the former. Vilhen the duct bridge passage is closed the air is promptly exhausted from chamber 81 by the pump through vent 83, thus restoring the valve disk 86 to its normal position. Chamber 72 being thus put again into communication with the pump, the chamber is instantly exhausted of air, causing diaphragm 74c to bring the cover or disk 76 down over aperture 77 and drawing the diaphragm 73 back to its normal position. This movement of the latter diaphragm 73 causes a quick exhaustion of air from the fly-wheel casing, thus permitting the atmosphere to press the casing disks into engagement with the wheel and causing a sudden expansion of the expression bellows, as previously described. The actuation of the link 8, however, continues'only until the stem 89 on diaphragm 78 engages the diaphragm 74 and so raises the lever 75, uncovering aperture 77 and restoring atmospheric pressure to the wheel casing, whereupon the springs 63 throw the disks 6 1, 65 out of contact with the fly wheel. in this manner each uncovering of the duct-bridge passage to which valve 7 8 is connected produces a quick and momentary expansion of the expression bellows, and a correspondingly more powerful operation of the playing pneu1natics. The extent of such expansion of the bellows, and hence the force with which the playing, pneuuiatics operate, plainly depend upon the length of time during which the fly wheel casing iscollapsed, which in turn depends upon the time required for the dia phragm 7 3 toreturn to its normal position and open aperture 77. Thus if the perforation in the tune sheet is long enough to keep 12 valve 7 8 reversed until diaphragm 73 moves to its limit of travel, a longer time will be required for the said. diaphragm to return and open aperture 77, and the link 8 will have a correspondingly longer movement. On the other hand, if the tune-sheet perforation is very short, only slight movement of the diaphragm 73 can occur. Hence by properly proportioning the length of' the perforations the degree of force imparted to the operation of the playing pneumatics maybe varied as desired, while any number of successive notes may be accented by pro riding the proper number of such perforations, as will be readily understood.

The device through which the expression bel ows is connected to the pump and to the vacuum chamber will now be described. Mounted transversely on the back plate 16 (Figs. 2, 4;, 5 andtl) at the hinge end of the expression bellows is a block 90, provided with a passage 91. At one end this passage is in communication with the expression bellows 1 through a groove in the base or back-plate, indicated. in dotted lines at 92, Fig. 4, and at its other end the passage is connected to the vacuum chest by the tube 1 (Fig. 1). Extending longitudinally of the block is a chamber 93 (Fig. 6) connected with passage 91 by way of a small chamber 91 and passage 95. Separated from the chamber 94 by a partition 96 is another small chamber 97, closed by a movable air-tight diaphragm 98, but in communication with passage 93 by an opening 99. Between the chamber 94 and passage 93 is a valve 100, the stem of which extends up through partition 96 into engagement with a diaphragm 98. This valve is normally held closed-by a spring 101, supported by a pin 102 and having its end bent into engagement with a screw 103 by which the tension of the spring on the valve may be regulated as desired. At the endof the block in which the said screw is fitted the passage 93 is connected with the tube 2 (Fig. 1) which leads to the air pump. From the same part of the said passage the tube 54 leads to the passage in the block 35, and other tubes, as 101:, 10-5, lead to the so-called accessory pneumatics, which operate the piano pedals, hammer rail, etc. The operation of the valve 100 will now be described. Tube 2 being connected with the pump, it is clear that-the maxin'mnr degree .of vacuum of which the pump is capable when in normal operation will be produced in. passage 93 and chamber 97. rrssuming that the expression bellows contains air at atmospheric pres sure, as will be the case when the pump is first started, it will be seen that the pressure of the air in chamber 94 and on diaphragm 98 will, as soon as the pressure .in 93 and 97 has fallen low enough, open or de- =-press valve 100 against the tension of spring 10].. Air will then be drawn out of the bellows 1 and the vacuum chamber 5 until the pressure therein, plus the atmospheric pressure on diaphragm 98, is insufficient to open" valve '100 against its spring and the pressure of the residual air ,in 93 and 97. As the playing pneumatics come into operation it is clear that'air will be admitted therethrough into thevacuum chamber and expression bellows, and hence by increasing thepressure therein, would'cause the valve 100 to be again opened. In the meantime,- however, the pedal, hammer-rail, or other accessory pneumatics come into operationand the air which they receive from the duct-bridge. of course flows to passage 93,

' increasing the pressure therein and aiding the spring 101 to keep the valve 100 closed until the pump can lower the pressure in 93. It will therefore be seen that by the operation described the accessory pneumatics, which in general require more, power than the playing pneumatics for satisfactory operation, are assured of having .the proper degree of vacuum 7 inv them, depending upon the tension of spring-101 as adjusted by the screw 103. In other words, no matter what the pressure in the expression bellows 1 may be, whether above or below the" normal, the valve 100 will not openunless the partial vacuum in the passage 93 and the accessory pneumatics is sufiicient to insure the proper operation of the latter.

In playing a long passage softly it may happen that so much air may be admitted to the expression bellows by the valve 2021s to makethe partial vacuum in the bellows and vacuum chesttoo slight for the proper actuation of the playing. pneumatios. In order to avoid this possibility meansr'are provided as follows in connectionwith the bellows In the top thereof is a chamber 106 (Fig. 4) closed by a diaphragm107, and

in communication with the interior. of the bellowsby a vent or minute passage 108. This diaphragm is connected to a lever 109' urged outwardly from the bellows-top by a flat springllO, the tension of which can be regulated by a screw 111. 'On the free end of the lever is a valve disk or cover'l12 adapted to close the mouth of a passage 113 connected by a tube 114 to the tube 14 which connectsthe valve 44 with the duct bridge. Since the chamber 106 is in communication with'the interior, of the bellows the pressure in said chamber and bellows 1s the same, and the diaphragm 107 is depressed by the pressure of the atmosphereagainst the tension of spring 110, carrying the disk 112 down upon the mouth of the passage 113. If now the pressure in the bellows,

and hence in chamber 106 also, should rise to a certain point, determined by the adjustment of spring 110, the latter will raise the lever and open passage 113, thereby ad- K mitting air to chamber 48 of valve 44 which controls diaphragm 34a The result is that the latter diaphragm is raised, which movement, it will be remembered, permits valve 20 to be kept closed by the spring 24. .Thus no more air can enter by way of valve 20 until the normal degree of vacuum is restored in the bellows and in chamber 106; whereupon the passage 113 is closed again by disk 112, with the same efiect on valve 44 and diaphragm 34 as has the closing of the duct-bridge passage with which said valve is connected.

The mechanism herein illustrated and de scribed has been found in practice to be thoroughly effective, being positive and cer tain, yet delicate, in operation, affording pleasing variation of expression in the playing of a composition. Moreover, it can be applied to existing instruments with no, or at most but slight alteration in the playing mechanism.

As previously stated, the form shown is merely the preferred embodiment of the invention, which may be embodied in other specific forms without departure from its proper scope as defined by the appended claims.

I am aware that there are instances in the prior art of expression regulators which however, perform only the functions ofvalve actuating pneumatics, corresponding to the pneumatics described herein and shown in Fig. at at 34: to 41. It will be sufficiently apparent after reading the foregoing specification that my invention performs additional functitms, by means of novel' mechanism operated in animproved manner. I wish to claim the differences broadly, and in so doing I shall use the term expression bellows, to indicate a bellows of variable pressure,- acting as' a receiver for the air exhausted from the striking pneumatics, under control which is entirely independent of the regular sustaining bellows, or the constant action of the pump.

What I claim is:

1. In a self playing musical instrument. the combination with a duct-bridge, a vacuum chamber, and an air pump, of an expression bellows connected with the pump and the vacuum chamber, a valve for admitting air into said bellows, a. pair of diaphragms operatively connected with said valve. one arranged to open the valve to admit air to the bellows, and the other arranged to disconnect the first from its op erative connection with the valve, and pneumatic means connected with the duct-bridge for controlling said diaphragms, as set forth. 5 I

2. In a self playing musical instrument, the combination of an expression bellows, yielding means tending to expand the be llows, a valve to admit air to the bellows but norm ally held closed by said yielding means, and pneumatically actuated devices for opening said valve against the tension of said yielding means.

3. In a self-playing musical instrument, the combination with a vacuum chamber, an air pump, and a duct-bridge, of an expression bellows separate from but pneumati-- cally connected with the vacuum chamber and constituting an auxiliary pressure source independent. of the air pump, means for applying power to said bellows, and pneumaticmcans connected, with the duct bridge for controlling said first means, as set forth.

*1. In a self-playing musical. instrument, the combination with a vacuum chamber, an air pump, asourceof power therefor, and a duct-bridge, of an expression bellows separate from but pneumatically connected with the vacuum chamber, a power-driven element, operating mechanism intermediate between the saidelement and the bellows to apply power to the same, including a' menf ber adapted to engage the power-driven ele ment'so as to be actuated thereby, and pneu matically operated means connected with the duct-bridge for causing momentary engagement of the said member with the power-driven element, as set forth.

5. in a self-playing musical instrument,v

the combination with a tracker bar, pneumatic playing instrumentalitics, a note sheet cooperating with the trackerbar, and a pump to exhaust air from the playing instrumentalities, of a. separate expression bellows in pneumatic communication with said instrumentalities and with the pump, and pneumatically controlled means under the control of the tracker bar and note sheet to apply power for suddenly expanding said bellows against its closing movement caused. by the exhaustaction of the pump.

6. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing instrumcntalities, a note sheet coiiperating with the tracker bar, and a pump to exhaust air from the playing-instrumentalities, of a separate expression bellows'in pneumatic communication with theinstrumentalities and with the pump, an inlet valve for said bellows, pneun'iatically controlled means controlled by the note sheet and tracker bar for operating said valve, and pneumatically operated means also under the control of the note sheet and tracker bar to apply power for suddenly expanding the expression bellows against its closing movement caused by the exhaust strumentalities, of a separate expression bellows in pneumatic communication with said instrumentalities and with the pump, means to actuate said expression bellows by power derived independently of its pneumatic connections, an inlet valve for the bellows, a lever engaging said valve, and pneumatically actuated means controlled by the note sheet and tracker bar for swinging said lever to open the valve.

8. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing I instrumentalities, a note sheet cooperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, of a separate expression bellows separate from but vin pneumatic communication with said instrumentalities and with the pump, means to actuate said expression bellows by power derived independently of its pneumatic connections, an inlet valve for the bellows, a lever engaging said valve, means for normally maintaining the valve closed, and pneumatically actuated means cont-rolled by the note sheet and tracker bar for swinging said lever to open the valve.

9. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet jcooperating with the tracker bar, and a pump to exhaust alr from the playing in strumentalities, of an expression bellows separate from but 1n pneumatic communication wlth' the said lnstrumentalitles and with the pump, means to actuate said expression bellows by power derived independentl} of its pneumatic connections, an inlet valve for said bellows, a lever engaging the valve, a spring engaging the lever to urge the valve to its seat, and pneumatically operated means under the'control of the tracker bar and note sheet for operating said valve to admit air to the bellows.

10. In a self-playing musical instrument,

I the combination with a tracker bar, pneumatic playing inst-rumen'talities, a note sheet cooperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, of an expression bellows communicating with said instrumentalities and the pump, an inlet valve 'for said bellows, a lever engaging the valve, said lever being composed of parts adjustable with relation to each other, one of which engages the valve,'a spring engaging another of said parts to swing the leverto urge the valve to its seat, and pneumatically operated means under the control of the tracker bar and.

note sheet. for operatingsaid valve to admit air to the bellows.

11. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, of an expression bellows communicating with the said instrumentali-' ties and the pump, an'inlet valve for said.

bellows, a spring acting upon the valve and pump to exhaust air from the playing instrumentalities, of an expression bellows communicating withthe said instrumentalities and the pump,;an inlet valve for said bellows, a lever engaging the valve, said le-' ver comprising longitudinally slidable parts adjustable relative to each other to regulate the length of the lever, one of said parts ene gaging the valve, a spring engaging the otherof said parts to urge the valve to its seat, and pneumatically operated means under the control of the note sheet and the tracker bar'for operating said valve to admit air to the bellows.

13. In a self-playing musical instrument,

the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar, and-a pump to exhaust air from the playing incat-ion with the said instrumentalitiesand with the pump, means for driving said bellows independently of said pneumatic communications, an inlet valve for said bellows, pneumatically operated means under control of the note sheet for opening saidvalve, and additional means independent of the sheet and tracker for closing the valve when the degree of vacuum in the expression bellows falls below a predetermined point.

14; In a self-playing musical instrument, the combination with aftracker bar, pneumatic playinginstrumentalities, anote sheet cooperating with the tracker'bar, and a pump to exhaust air from the playing instrumentalities, of an expression bellows communicating with said instrumentalities and the pump, an inlet valve for the be].- lows, pneumatically controlled means for opening the valve when the degree of vacuum in the bellows increases beyond a predetermined point, and means under the control of the notesheet and tra'cker bar for rendering said pneumatically operated means ineffective to open the valve.

15. In a self-playing musical instrument, the combination with'a tracker bar, pneumatic-playing inst-rumentalities, a note sheet cooperating with the tracker bar, and a strumentalities,1of a'separate-power driven 1 expression bellows in pneumatic communi- I lows constituting pump to exhaust air from the playing instrumentalities, of a separate expression belvice communicating with the said instrumentalities and the pump, a rotary driving element, means r'or rotating the same, and means for coupling the expression bellows to said element whereby the latter applies power to impart a quick opening movement to the bellows.

16. In a self-playing musical instrument,

the combination with a tracker bar, pneumatic playing instrument-alities, a note sheet cooperating with the tracker bar, and a pump .to exhaust air from the playing instrumentalities, of a separate expression bellows constituting an auxiliary exhaust device communicating with the said instrumentalities and the pump, a rotary driving element, means for rotating the same, means for coupling the expression bellows to said element whereby the latter applies power to impart a quick opening movement to the bellows, and pneumatically actuated means For operating said coupling means.

17. In a self playing musical instrument, the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar, and a pump to exhaust air from theplayinginstrumentalities, of a separate expression bellows constituting an auxiliary exhaust device communicating with the said instrumentalities and the pump, a rotary driving element, means for rotating the same, means for coupling the-expression bellows to said element whereby the latter applies power to impart a quick opening movement to the bellows, and pneumatically actuated means under the control of the note sheet and tracker bar for operating said coupling means. I 1

18. In a self-playing musicalinstrument, the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar, and a pump to exhaust air from the playin instrumentalities, of an expression befiows communicating with. the said instrumentali-f ties and-the pump; a rotary element, means for rotating the same, a collapsible chamber surrounding said element, saidchamber be ing connected to the expression bellow, and means for collapsing .said chamber to couple it to said rotary element to move therewith to impart'an opening movement, to the bellows.

19. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, of an expression bellows communicating with the said instrumentali ties-and the pump, a rotary element, means an auxiliary exhaust de,

of the notes, sheet and tracker whereby the pressure in to rotate the same, a collapsible chamber surrounding said element, said chamber bein connected to the expression bellows, an means for exhausting air from the chamber tocause it to collapse into engagement with said element and move therewith to impart an opening movement to the bellows.

20. the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cobperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, of an expression bellows communicating with the said instrumentalities and the pump, a rotary element, means to rotate the same, a collapsible chamber surrounding said element, said chamber being connected to the expression bellows, and pneumatically operated means for exhausting air from the chamber to cause it to collapse into on agement with said element and move therewith to impart an opening move ment to the bellows.

21. In a self playing musical instrument,

the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar, anda pumpj-o exhaust air "from the playing instrumentalities, of an expression bellows communicating with the said instrumentalities and thepum'p, a rotary element, means to rotate the same, a collapsible chamber surrounding said element, said chamber being connected to the expression bellows, and neumatically operated means under control N bar for exhausting air, from the chamber to cause it to collapse into engagement with said element and move therewith to impart an opening movement to the bellows. p

22. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing instrumentalitiesa note sheet cooperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, of an expression bellows communicating with said instrumentalities and the pump, means under the control of the. notesheet and tracker bar for admitting air directly to the bellows, and means exposed to the pressure inthe bellows adapted to act upon and regulate said air'control, the bellows may be maintained approximately constant.

23; In a self-playing musical instrument, the-combination with atracker bar, pneumaticplaying instrumentalities, a note sheet cdoperating with the tracker bar, and a pump to exhaust air from the playing instrumentalities, or" an expression bellows communicating with the said instrumentalities and the pump, a rotary ele ment, means for rotating the same, a collapsible chamber surrounding said element, said chamber being connected to the expression bellows,

In a self-playing musical instrument,

the bellows,

means for collapsing said chamber to couple it to said rotary element to move therewith to impart an opening movement to the bellows, and means for expanding said chamber out of engagement with the rotary element.

24. In a self-playing musical instrument, the combination with a tracker bar, pneumatic playing instrument-alities, a note sheet cotiperating with the tracker bar, and a pump to exhaust air from the playin instrumentalities, of an expression be lows communicating with the said instrumentalities and the pump, means for rotatin the same, a collapsible chamber surroun ing said element, said chamber being connected to the expression bellows, means for collapsing said chamber to couple it to the rotary element to move therewith to impart an opening movement to and a spring for expanding said chamber out of engagement from the rotary element.

25. In a self playing musical instrument,

' strumentalities,

a rotary element,

the combination with a tracker bar, pneumatic playing instrumentalities, a note sheet cooperating with the tracker bar and a pump to exhaust air from the playing inof an expression bellows communicating with the said instrumentalities and the pump, a rotary element, means to rotate the same, a collapsible chamber surrounding said element, and means for exhausting air from the chamber to cause it to collapse into engagement with said ele ment and move therewith to impart an opening movement to the bellows, said exhaustmg means comprising an air chamber hav ing a movable wall and pneumatically operated means for controlling the movements of said wall to draw the air from the collapsible chamber.

GREN J.. FAIROHILD.

Witnesses;

HARRY G. PERKINS, M. P. HOWARD.

Images