USRE16729E

USRE16729E - By american

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Publication number: USRE16729E
Authority: US
Publication date: 1927-08-30

Description

Aug. 30. 1927.

' R 16,729 G. M. RUSSELL AUTOMATIC MUSICAL INSTRUMENT Origi l Filed Dec. 26, 1917 2 6 I 8 f cIIJIKI/ LD 3 6 56 .1? 72 45 42 34 4 44% as; 47 8 I l Ii 48 v I 49 Reissued Aug. 30, 1927 UNITED STATES Re. 16,729 PATENT OFFICE,

v GUY MANLY RUSSELL, DECEASED, LATE OF SYRACUSE, NEW YORK; BY AMERICAN PIANO COMPANY, or Nnw'YonK, N. Y ASSIGNEE.

AUTOMATIC MUSICAL INSTRUMENT.

Original mi. 1,409,497, dated March 14, 1922, Serial No. 208,758, filed December 26, 1917. Application for reissue filed March 12, 1924. Serial No. 698,783.

This invention relates to automatic means for playing'musical lnstruments such, for

nstance, .as' pianos; and pertains more particularly to means for governing and varymg tone intensities.

The principal object of the invention is.

i to provide apparatus capable of producing ings show diagrammatically one practicable a great number of variations in intensity of playing; such apparatus comprising preferably, though not essentially, a combination of means for producing crescendo and diminuendo efiectsand also for instituting various defined grades or'ste'ps of playing intensities. 1

For illustration the accompanying drawembodiment of the invention employing suitable pneumatically governed devices in cooperation with a piano action; but as will appear to those skilled in the art, the invention is susceptible of embodiment in various constructions and organizations other than that particularly shown and described herein. It will be equally apparent that all thefeatures of the invention need not be used conjointly, since their respective advantages may accrue from their separate application in any practicable manner to a suitable instrument.

The drawings consist of a diagrammatic representation of a portion of a typical player action with operating and governing means exemplifying the application and utility ofthe invention.

In the drawings a striker or player pneumatic l is provided, having a sticker 2 to' act upon a wippen 8 and thereby operate the usual piano action, as well understood in the art. A wind trunk 4 leads to a wind chest 5 forthe player pneumatics, each of which I has a secondary valve 6 controlled by a primary valve 7 which is operated from a tracker board 8 through a duct .9 in the usual manner.

The wind trunk 4 communicates with the interior of'a reservoir bellows 10. An exhaust pump '11 constitutes a main source of power and is directly connected with the reservoir bellows 10 by a duct 12. The exhaust pump may be driven by an electric motor 13. For convenience the; exhaust pump and motor are shown on a greatly reduced scale and it will of course be understood that' any suitable exhausting appara tus, whether power driven or not may be employed in carrying out the invention.

The bellows 10 has a stationary board 14 and a movable board 15. movable board is a spring 16 which at its outer end is fast to an adjusting screw 17 threaded in a fixed abutment 18. The reservoir bellows is provided with a relief valve 19 cooperating with a port 20 opening to the bellows and herein conveniently located in the movable board 15. The valve 19 is threaded upon a valve stem 21 and supported by a'suitable'bracket 22. A light spring 23 tends normally to hold the valve 19 against its seat. i V

.In operation the pump'll tends to exhaust air from the bellows 10, from the wind trunk 4, and-the wind chest 5 with which the play- .er pneumaticsare connected selectively. It

will be readily understood by those skilled scribed.

Apparatus embodying this invention may have a three-fold capacity for controlling the valve 19 and the consequent degree of exhaust within the wine chest 5. The apparatus may perform a regulating function, that is it may maintain any given playing intensity whether one or many notes be sounded; it may produce automatically continuously progressive changes in playing intensities for crescendo and diminuendo purposes; and it may produce automatically incremental changes in pla *ing intensities.

These three capacities of the apparatus will be described in the sequence indicated.

The bellows apparatus previously referred to is herein shown mounted within the reservoir bellows 10 and preferably attached to its fixed board 14. It comprises a bellows 25 having a movable board 26 hinged to the fixed board of the reservoir bellows 10, and a number of bellows attached to the movable board 26 of the bellows 25. Herein are shown three bellows 27 28 and 29 separated Attached to the 19 it may be assumed that the bellows 27, 28 and 29 are open to atmosphere and it will later appear a degree of exhaust with- IRS in the wind chest 5 will thereby be estab bellows apparatus will tend to hold the four bellows 25, 2'7, 28 and 29 in fully expanded position. As the reservoir bellows collapses the stem 21 will bear against the board 32 of the bellows 29 and hold the valve so that upon further collapse of the reservoir bellows atn'iosphere will be admitted through the port 20. hen this opening of the port 20 takes place the tension of the s n'i'ng will substantially equal the force provided by the differential between the exhaust and atmosphere acting upon the area of the board 15. Therefore, by proper adjustment of the valve upon its stem or of the spring through its adjusting nut, a normal minimum degree of exhaust may be established. I

During the playing of the instrument atmosphere is being admi ted in varying amounts, principally by the operation of the player pneumatics which when at rest contain atmosphere. To maintain the pressure substantially uniform the admission of atmosphere through the player pn-eumatics may be compensated by a corresponding lessening of the amount of atmosphere being admitted past the valve 19. A sudden influx of atmosphere through the player pneu-v matics may cause a momentary slight decrease in the pressure within the reservoir bellows. This slight decrease will permit the board 15 to move toward the va zethus closing slightly the atmosphere port. This in turn will cause the pump to take a relatively larger amount of air from the wind chest 5 and thereby restore the normal mini mum degree of exhaust. The reservoir bellows and its valve respond so quickly to minute fluctuations of exhaust wit n the wind chest 5, that the effect is maintain the degree of exhaust than to re store it, as will be readily understood by those skilled in the art.

Having described the regulating functions of the apparatus, the means for producing crescendo and diminuendo effects will now be described.

It will be readily understood by those skilled in the art that if any one of the ex- 25,

pression pneumatics

25, 27, 28 or 29 is 001- lapsed the pumping mechanism will establish a higher degree of exhaust within the reservoir and also within the. wind chest 5 before the valve 19 can operate to admit atmosphere. This results, in the specific construct-ion shown, from a movement of the abutment 32 toward the fixed wall of the reservoir bellows and necessitates afurther movement of the movable board toward the fixed board 14 before the stem 21 of the valve will contact with the abutment 32. This movement of the board 15 elongates the spring 16 thereby increasing its. pull upon the board 15 and necessitating a greater differential between exhaust and atmosphere to overcome and balance this increased pull.

For crescendo and diminuendo purposes the pneumatic is herein selected. The interior of this pneumatic, which may be termed a crescendo pneumatic, is connected by a duct 33 with a valve box 34.

Ducts

35 and 36 connecta wind chest 37 within the valve box 34 with the wind trunk 4 so that this wind chest 37 is always in communication withthe interior of thereservoir bellows 10. The duct 33 is connected with the channel 38 in the valve box which leads to a. valve chamber 39 having a port 40 to atmosphere and a port 41 to the exhaust chamber 37 A valve 42 is mounted within the valve chamber 39 and its stem rests upon a diaphragm 43 covering a diaphragm chamber 44. The usual bleed is provided in this and similar 'diaphragms. A duct 45 leads from this diaphragm chamber to a vent 45 in the tracker bar 8. In the channel 38 are two obstruction screws 46 and 47, of which the screw 46 restricts the channel 38 to a greater extent than the screw 47. A by-pass 48 is provided, which when open permits the passage of air around the obstruction screw 46. A by-pass valve 49 is mounted upon a diaphragm 50 over a diaphragm chamber 51. This diaphragm chamber isconnected by a channel 52 with a valve chamber 53 having a port- 54 to atmosphere and a port 55 to the exhaust chamber 37. A valve 56 is mounted in the valve chamber 53 and its stem rests upon a diaphragm 58 covering a diaphragm chamber 57. This diaphragm chamber is connected by a duct 59 with a vent 59 in the tracker bar 8.

As the parts are shown in the drawings,

the crescendo pneumatic 25 is open to atmosphere through the duct 33, channel 38 atmosphere port 40. If the valve 42 is operated to close the atmosphere port 40 and open the exhaust port 41, as for instance, by the opening of the tracker vent 45' by the note sheet, the pneumatic 25 will be placed in communication with reservoir bellows 10. Connecting the pneumatic 25 with he reservoir bellows 10 will tend to equalize the pressures upon opposite sides of the board 26 and initiatea collapsing movement of the pneumatic 25 due to the slight pres-' sure of the spring 23 through the valve stem 21. -This results'in a partial closing of the valve 19, a reduction inthe amount of atmosphere drawn through the port and a consequent slight increase in the degree of exhaust within the reservoir bellows 10.

This increaseis accompanied by a further increase within the pneumat1c25 and a further collapse of the reservolr bellows.

' This action will continue until the pneupany a slow decrease-in the de.

matic is fully collapsed. The communication between the pneumatic 25 and reservoir bellows 10, in the described operation,

is restricted by the obstruction gscrew 4 7 which provides the greater restriction, This restriction in communication willreta'rd the equalizing of pressures within the pneumatic 25 and bellows 10 so that the collapsing movement of the pneumatic 25 willbe slowed up and the consequent increase of the degree of BXl'AELUSt WltlHH the bellows' l0 accomplished slowly at a speed appropriateto a slow crescendo.

y A slow diminuendc, which will .ac coing e or exhaust within bellows 10, may be accomplished by admitting atmosphere slowly to pneumatic 25 as for instance by the closing of exhaust port lland the opening of atmosphere port 40' by the valve 42. Thls valveoperation may be initiated by closing the tracker vent The apparatus thus has the capacity ofproducing a slow crescendo and'a slow diminuendo. To provide for faster crescendo and diminuendo operations the valve 56 may be appropriatelyv operated to by-pass the obstruction screw 46, which may be conveniently called the slow crescendo adjustment screw, while 47 may be called the fast crescendo adjustment screw. For example, if a fast crescendo is desired the tracker ducts 45 and .59 may be simultaneously opened thereby operating valves 42 and 5G simultaneously; the result of operation of "alve 42 being to connect the pneumatic 25 with the interior of the reservoir bellows 10 and the result of operation of the valve being to by-pass obstruction screw 46 and thus enlarge the effective openmg of the channel 38.

As will be readily understood by those skilled in the art, a crescendo may be started at one speed and changed to another speed intermediate its extreme limits; a fast diminuendo mayfollow a slow crescendo and vice versa and other varying combinations of crescendo and diminuendo effects can be produced.

Having sufficiently described the regulating functions of the apparatus, the crescendo and diminuendo functions, the manner of r producing incremental intensity changes will now be described.

g It is desirable to have'the apparatus capable of producing substantially instantaneous incremental changes, of varying degrees, in playing intensities. For this purpose the pneumatics 2'7, 28, and 29 are utilized. These pneumatics'are of different sizes arranged so that th y may be collapsed individually or in combination to effect their separate or'combined results as presently described.

A description of the operationof one of these pneumatics, for instance pneumatic 27, will suflice for all. The interior of pneumatic 27 is connected by a fleftible duct 69. a nipple 61, a duct 62 and a channel to with avalve chamber G l havin a port 65 to atmosphere and a port 66 to an exhaust chamberfili. This exhaust chamber is connected by a duct 68, a duct 69, the duct 35 and the wind trunk 4 with the interior i mounted within the valve: chamber 74 and r rests upon a'diaphragm 78 over a diaphragm chamber 7 9. The diaphragm chamber 7 9 is connected by a duct 80, with a tracker vent correspondingly numbered. The parts last described are duplicated for pneumatics 28 and 29 and bear the samenumbcrs with indices a andV) respectively.

' In describing the operation of the pneumatics 27, 28 and 29 it will be assumed that atmosphere is present at. all times in the crescendo pneumatic '25. If the tracker vent 80 is opened to admit atmosphere under the diaphragm 7 8, the valve 77 will be operated to close exhaust port 76and open atmosphere port 75 thus admitting atmosphere to the channel 73 and to the diaphragm chamber 72. The admission of atmosphere to this diaphragm chamber will operate valve 70 to close atmosphere port 65 and open ez zhaust port 65 thus placin the pneumatic 27 in communication with the interior of the reservoir bellows 10. This communica tion between the pneumatic 27 and the reservoir bellows 10, beingvfree and unrestricted the pressure within pneumatic 28 will be equalized. with the pressure in the reservoir bellows 10 substantially instantaneously and will inaugurate a collapsing movement of the pneumatic 27' in the manner previously described in connection with pneumatic 25, with the exception that the complete collapse of pneumatic 2'? will be attained substantially instantaneously.

This quicltcollapse of the pneumatic 27 will be accompanied by a quick colla )se of the reservoir bellows and a corresponding are increase in the degree of exhaust therein and in the wind chest 5 to increase playing intensities by a substantially distinct increment. Upon closing the tracker vent 80, atmosphere will he suddenly admitted to the pneumatic 2.7 and it will tend to open the valve 19 thus permitting a quick expansion of the reservoir bellows and a consequent sudden decrease in the degree of exhaust therein.

It will be readily understood that the extent of this incremental change in playing intensity will bear a certain relation to the extent of movement of the pneumatic 27. If, therefore, pneumatics 28, and 29 are of a diiferent size, incremental changes of different extents may be secured by the separate collapse of any of these bellows. It will also be understood that the bellows may be collapsed in varying combinations thereby providing a substantial range of incremental intensity changes.

It is desired that the maximum degree of exhaust which may be inaugurated by the crescendo mechanism be substantially the same as the maximum degree of exhaust attainable by step change mechanism and therefore the movement of the abutment 32, by the collapse of the crescendo pneumatic 25, is made substantially the same as its movement upon collapse of all three expression pneumatics 27, 28 and '29.

It is also desirable that the incremental intensity change mechanism and the crescendo mechanism be operable concurrently so that a crescendo effect may be superposed upon an existing incremental effect or a note or notes may be accented during the progress of a crescendo. To provide for this and to prevent the apparatus from exceeding the maximum a fixed arm 81 is mounted within the reservoir bellows and a collar 82 is threaded upon the valve stem 21. The collar 82 may be so adjusted upon the valve stem that it will come in contact with the arm 81 when the desired maximum degree of exhaust has been attained.

It will be readily understood by those skilled in the art how the superposing of expression effects may be accomplished by appropriate perforations in the note sheet. For example, if it is desired to accent a note during a slow crescendo any one or all of the pneumatics 27, 28 and 29 may be suddenly opened to the reservoir bellows 10 and atmosphere admitted again without disturbing the slow collapse of the pneumatic 25. Similarly if it is desired to start a crescendo from some intermediate step attained for instance by the collapse of pneumatic 27, the crescendo pneumatic 25 may be opened to the reservoir bellows and the abutment 32 will be slowly moved until the stop 82 comes in contact with the arm 81 when the maximum playing intensity has been attained. Many other and varied effects may be attained singly or in combina tion as will be understood by those skilled in the art.

It is to be understood that the invention shown in the diagrammatic construction of the drawings, may be variously modified and embodied within the scope of the subjoined claims. y

I claim as my invention:

1. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power foroperating the playingpneumatics; a reser voir bellows having constant communicaion with the main source of power and the wind chest for the playing pneumatics; and

crescendo means within the reservoir bellows automatically operating to vary the action of said reservoirbellows to produce a substantially continuous progressional change in playing intensities for crescendo purposes.

2. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a governor bellows having unrestricted communication with the main source of power and the wind chest for the playing pneumatics; a tracker; and a tracker controlled crescendo pneumatic to vary the action of said governor bellows to produce a substantiallv continuous progressional change in playing intenslties for crescendo purposes.

3. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating. the playing pneumatics; a governor bellows having unrestricted communication with the main' source of power and the wind chest for the playing pneumatics; crescendo means to vary the action of said governor bellows to produce a substantially continuous progressional change in playing intensities for crescendo purposes; and speed governing means for the crescendo means.

4. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a governor bellows having unrestricted communication with the main source of power and the wind chest for the playing pneumatics; a tracker; a tracker controlled crescendo pneumatic to vary the action of said governor bellows to produce a substantially continuous progressional change in playing intensities for crescendo purposes; and tracker controlled speed governing means for the crescendo pneumatic.

5. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a governor bellows having unrestricted communication with the main source of power and the wind chest for the playing pneumatics;

the wind chest for the playing pneumatics;

a tracker; and tracker controlled expression means to vary the action of the governor bellows by substantially distinct increments for producing intensities. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a reservoir bellows provided with a port to atmosphere and having constant communication incremental variations in playing with the main source of power and the wind chest for the playing neumatics; a valve to control admission of atmosphere to said reservoir bellows; an abutment against which said valve normallybears; and means to move said abutment slowly to producecrescendo effects in playing intensities.

.8. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a. main source of power for operating theplaying neumatics; a reservoir bellows provided with a port to atmosphere and having constant communication with the main source of power and the wind chest for the playingpneuma'tics; a valve to control admission of atmosphere to said reservoir bellows; an. abutment against which said valve normally bears; a tracker; and tracker'controlled means to move said abutment slowly .to produce c'rescendo effects in playing intensities. 7

9. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the laying neumatics; a reservoir bellows provi ed with a port to atmosphere and havmg. constant communication with the main source of power andthe wind chest for the playing penunratics; a valve to control admission" of atmosphere to said reservoir bellows; an abutment against which said valve normally bears; and means to move said abutment suddenly to produc e incrementalrchanges in playing intensitles.

10. In an automatic musical instrument the combinat-ion of playing Pneumatics;- a

wind chest therefor; amain source of power for operating the playerpneumatics; ares-- ervoir bellows provided .with a port to atfor operating the playing mosphere and having constant communication with the main source of power'and the wind chest for the playing pneumatics; a valve to control admission of atmosphere to said reservoir bellows; an abutment against which said valve normally bears; a tracker; and tracker controlled means tomove said abutment suddenly to produce incremental changes in playing intensities.

11. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main sourceof power for operating the playing pneumatics; a reser-, voir bellows having constant communication with the main source of power and the wind chest for the playing pneumatics; a valve to control admission of atmosphere to said reservoir bellows; an abutment againstwhich said valve normally bears; means to move said abutment slowly to produce crescendo effects in playing intensities; and

means to move said abutment suddenly to produce incremental changes in playing in tensities. v o v v 12. In an automatic musical instrument the combination of playing pneumatics; 'a wind chest therefor; a main source of power 'pneumaties; areservoirbellows having a port to atmosphere and connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a valve governing pneumatic mounted within said reservoir bellows; and means to place said pneumatic in communication with said reservoir bellows to vary playing intensities. V

13. In an automatic musical instrument the combination of playing pneumatics"; a wind chest therefor; a main source of power for operating the playing pneumaticsya reservoir bellows. having va port to atmosphereand connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a valve. governing crescendo pneumatic mounted within said reservoir bellows; and means to place said pneumatic in communicationwith, said reservoir bellows through .a restricted opening.

I 14. In an automatic musical instrument the combination ofplaying Pneumatics; awind chest therefor; a main source of power for operatingthe playing pneumatics; a reservoir bellows having a port to atmosphere and connected to the wind chest for the playing pneumatics a valve controlling said atmosphere port to said reservoir bellows; or valve governing crescendo pneumatic mount ed within said'reservoir bellows; means providing restricted connections of different capacities from said pneumatic to said reservoir bellows; and means for selectively controlling said connections.

15. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a ervoir bellows having a port to atmospher and connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a valve governing pneumatic mounted within said reservoir bellows; a tracker; and tracker controlled means to place said pneumatic in communication with said reservoir bellows to carry playing intensities.

16. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a reservoir bellows having a port to atmosphere and connected to the wind chest for the playing pneumatics; valve controlling said atmosphere port to said reservoir bellows; a valve governing crescendo pneumatic mounted within said reservoir bellows; a tracker; and tracker controlled means to placesa'id pneumatic in communication with said reservoir bellows.

17 In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a re:- ervoir bellows having a port to atmosphere and connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a valve governing crescendo pneumatic mounted within said reservoir bellows; means providing restricted connections of different capacities from said pneumatic to said reservoir bellows; a tracker; and tracker controlled means for selectively opening and closing said connections.

18. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a'main source of power for operating the playing pneumatics; a reservoir bellows having a port to atmosphere and connected to the wind chestfor the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a plurality of valve governing pneumatics mounted within said reservoir bellows; and means for selectively connecting said pneumatics with said reservoir bellows.

19. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a resc voir bellows having a port to atmosphere and connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said res-ervoir bellows; a plurality of valve governing pneumatics mounted within said reservoir bellows; a tracker; and tracker controlled means for selectively connecting said pneumatics with said reservoir bellows.

20. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a reservoir bellows having a port to atmosphere and connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a plurality of valve governing pneumatics having diiferent extents of movement mounted within said reservoir bellows; and means for selectivelyconnecting said pneumatics with said reservoir bellows.

21. In' an automatic musical instrument the combination of playing pneumatics; a wind chest therefor; a main source of power for operatingthe playing pneumatics; a reservoir bellows having a port to atmosphere and connected to the wind chest for the playing pneumatics; a valve controlling said atmosphere port to said reservoir bellows; a plurality of valve governing pneumatics having difi'erent extents of movement mounted within said reservoir bellows; a tracker; and tracker controlled means for selectively connecting saidpneumatics with saidreservoir bellows.

22. In an automatic musical instrument the combination of playing pneumatics; a wind chest therefor a main source of power for operating the playing pneumatics; a reservoir bellows having a port to atmosphere and connected to the wind chest for the play-' ing pneumatics; a valve controlling said atmosphere port to said reservoirbellows; a plurality of valve governing pneumatics mounted within said reservoir bellows; means to connect one of said pneumatics with said reservoir bellows through a restricted opening to produce crescendo effects in playing intensities; and means to connect other of said pneumatics selectively with said reservoir bellows throughunobstructed openings to produce incremental elfects in playing intensities.

23. In an automatic musical instrument, the combination of playing, pneumatics; a wind chest therefor; a main source of power for operating the playing pneumatics; a

governor bellows having unrestricted communication with the main source of" power and the wind chest for the playing pneumatics; a tracker; and a tracker controlled expression means to vary the action of the governor bellows by substantially distinct increments for producing incremental variations in playing intensities and also to produce a substantially continuous progressive change in playing intensities for crescendo purposes. I

24. In an automatic musical instrument the combination of a wind chest; a main source of power; a governor bellows having unrestricted communication with the main source of power and the wind chest; and eX- llii) pression means automatically operating to vary the action of the governor bellows by substantially distinct increments for producing incremental variationsof pressure in thewind chestL.

25. In an automatic musical instrument the combination of a wind chest; a main source of power; a governor bellows having unrestricted communication with the main source of power and the wind chest; and tracker controlled expression means to vary the action of the governor bellows by substantially distinct increments for producing incremental variations of pressure in the wind chest.

26. In an automatic musical instrument having the usual playing pneumaticsan d main source of power, in combination, a

wind chest; a reservoir bellows having communication with atmosphericair and con-' nected to the wind chest; a valve controlling said communication with atmospheric air; a valve governing pneumatic: and means to place said pneumatic in communication with said reservoir bellows to vary playing intensities.

27. In an automatic musical instrument having the usual playing pneumatics and a main source of power, in combination, a wind chest; a reservoir bellows having communication with atmospheric air and connected to said wind chest: a valve controlling said communication with atmospheric air; a valve governing pneumatic; a tracker; and

tracker controlled means to place said pneumatic in communication'with said reservoir bellows to vary playing-intensities.

"28. In an automatic musical instrument having the usual playing pneumatics and a main source of power, in combination, a wind chest; a reservoir bellows having communication with atmospheric air and connected to said wind chest: a valve controlling said communication with atmospheric air; a plurality of valve governing pneumatics: and means for selectively connecting said pneumatics with said reservoir bellows.

29. In an automatic musical instrument having the usual playing pneumatics and a main source ofpower, in combination, a wind chest; a reservoir bellows having communication with atmospheric air and connected to said wind chest: a valve controlling said communication with atmospheric air; a plurality of valve governing pneumatics having different extents of movement; and

means for selectively connecting said pneumatics with said reservoir bellows.

30. In an automatic musical instrument having the usual playing pneumatics and a main source of power, in combination, awind chest; a reservoir bellows having communication with atmospheric air and connected to said wind chest: a valve controlling said communication with atmospheric air;

and a plurality of valve governing pneumatics having different extents of movement; a tracker; and trackercontrolled means for selectively connecting said pneumatics with said reservoir bellows.

31'. Iii-combination with a musical'instrument having playing pneumatics and a source of power, means to govern the action of'the source of power including a pneumatic, means providing a port to atmosphere, awalve for said port controlled by the movable board of said pneumatic and supplementary tracker controlled pneumatics for varyingthe action of'said first-named pneumatic upon said valve. i

32. In an automatic musical instrument, having a wind chest and a main source of power, in combination, a regulator bellows having unrestricted communication with the main source of power and wind chest and adapted to maintain pressures therein at a substantially constant level; a tracker; and tracker controlled pneumatic means to vary the operation of said regulator to cause it to maintain pressures in said wind chest varying by predetermined increments.

33. In an automatic musical instrument, having a wind power, in combination, a chamber having communication with the wind chest and source of power and having a movable wall responsive to changes of pressure therein; a port through which atmospheric air may be admitted to said chamber; a valvecontrolling said port; means whereby movement of the movable wall afiects the valve to thereby maintain a. predetermined pressure in'the system at a substantially constant level; and pneumatic means for varying said lastnamed means to cause the position of the movable wall to be changed whereby the pressure maintained in the system is changed.

34:. Expression controlling mechanisms for musical instruments having player pneu matics and a mainsource of power, including, in combination, an exhaust chamber having a port providing communication between said chamber and atmosphere, a valve controlling said port, a pneumatic control ling said valve, and a plurality of supplementary pneumatic-s for varying the action of said first-named pneumatic on said valve to vary exhaust in said exhaust chamber by perceptible increments.

35. Expression controlling mechanisms for musical instruments having player pneumatics and a main source of power, including. in combination. an exhaust chamber having a port providing communication be tween said chamber and atmosphere, a valve controlling said port, a pneumatic controlling said valve, and a plurality of supplementary pneumatics having different extents of movement for varying the action of said pneumatic on said valve to vary exhaust in chest and a main source of said exhaust chamber byperceptible increment's.

Expression controlling mechanisms-for musical instruments having player. pneumatics and a main source of power, including, in combination, an exhaust chamber having a port providing communication between said chamber and atmosphere, a valve controlling said port, a pneumatic controlling said valve, a plurality of supplementary pneumatics for varying the action of said first-named pneumatic on said valve to vary exhaust in said exhaust chamber by perceptibleincrcments, a tracker, and valves controlled by said tracker to control the operation of said supplementary pneumatics.

37. Expression controlling mechanisms for musical instruments having player pneumatics and a main source of power, including, in combination, an exhaust chamber having a port providing communication betweensaid chamber and atmosphere, a valve controlling said port, a pneumatic controlling said valve, a plurality of supplementary pneumatics having different extents of movement for varying the action of said first named pneumatic on said valve, a tracker, and valve devices controlled by said tracker for selectively operating said suphaving a port providing communication beplementa'ry pneumatics to vary exhaust in said exhaust chamber by perceptible increments.

38. Expression controlling mechanismsfor musical instrun'ients having player pneumatics and a main source oi power, including, in combination, an exhaust chamber tween said chamber and atmosphere, a valve controlling said port, a pneumatic controlling said valve, a plurality of supple-mentary pneumatics having d'iiierent extents of movement for varying the action of said first named pneumatic on said valve, a tracker, and tracker controlled means for operating one of said supplementary pneumatics to vary exhaust in said exhaust chamber by a predetermined increment, and tracker controlled devices for operating a diiierent supplementary pneumatic to vary exhaust in said chamber by a different increment.

In testimony whereof, this specification has been signed this 10th day of March, 1924.

AMERICAN PIANO COMPANY, A sir nee of Guy Mcmly Russell, Deceased.

By 1. E. EDGAR,

- Trees.