US1431907A

US1431907A - Pneumatic power generator

Info

Publication number: US1431907A
Application number: US318886A
Authority: US
Inventors: Stanley S Cramer
Original assignee: Individual
Current assignee: Individual
Priority date: 1919-08-21
Filing date: 1919-08-21
Publication date: 1922-10-10
Anticipated expiration: 1939-10-10

Description

S. S. CRAMER.

PNEUIIIATIC POWER GENERATOR.

APPLICATION FILED AUG-.21,- 1919.

Patented Oc. 10, 1922.

3 SHEETSYSHEEI 2.

S. S. GRANIER.

PNEUMATIC POWER GENERATOR.

APPLICATION FILED AUG.21. 1919.

Patented Oct. 10, 1922.

3 SHEETS-SHEET 3.

IlI u Patented Oct. 10, 1922.

UNITED STAT-Es STANLEY S. GRANIER, F CAIEN,y NEW JERSEY.

` PNEUIATIC POWER GENERATOR.

Applieation led August 21, 1919. Serial No. 818,886.

T o all 'whom it may concern:

Be it known that I, STANLEY S. CRAMnn, a citizen of the United States, residin at 'Camdem `in the county of Camden and tate `of New Jersey, have invented. certain newl and useful Improvements' in Pneumatic Power Generators, of which the vfollowing is a specification.

This invention relates to pneumatic power generators, and particularly to rotary mechanisms for creating a vacuum such as 1s used in automatic or player-pianos.

Heretofore, it has been quite generally'the practice to employ inYplayer-pianos `pedaloperated bellows for the purpose of creating the vacuum necessary to` actuate the various hammers, expression devices, .winding and re-winding mechanisms, etc., but with this type of generator the effective vacuum usually obtained is 'sulicient to'support only a twelve-inch column of water. With the relatively limited possibilities incident to sucha low vacuum equivalent, the scope of 'the musical reproducing powers of the instrument is greatly restricted.

Therefore, in order to materially 'improve the quality of reproduction of agiven instrument, and in order to make such reproduction as nearl 80 with the original creation by a master pianist, it has been found absolutely essential to rovide a source of much higher power than lias heretofore been attainable, thus making it possible to strike the chords with greater force, to vbring into play the desired notes more instantaneously, and numerous other achievements which are only attainable with a relatively high pneumatic power at ones instantaneous command. 40

obtain the results mentioned, it has been `found necessary to have amore continuous v power than that created by any known form of rintermittent bellows mechanism, wherefore, it has been found that the only means which will producethe desired result` is a high-speed electric motdij. running preferably at' from 8,000 to 12,000 revolutions per minute, and so constructed as. to'inaintain a vacuum equivalent .to a twenty-four to thirty-inch water column. y However, although various types of, elec tric/motors have been used as blowersg'and to a certain extent as vacuum-creating means in various other devices such,for instance,

identical in tone qualities In addition to the foregoing, in yorder to a motor. possesses, whereby, there is undoubtas vacuum-cleaners, Ventilating systems, and the like, extensive experiment has proved that nothing previously perfected in any other art is capable of fulfilling the extremely exacting .requirements .of the automatic or player-piano industr One of the main details whichrit has been necessary to work out and perfect to the highest possible degree is that of insuring an absolutely noiseless operation of such a motor, entirely free from even the slightest degree of vibration,yas suchl vibration transmitted to any of the neighboring parts of a music instrument as, for instance, a piano, will set up audible vibrations of the latter which will be highly detrimental and injurious to the instrument, if not entirely fatal to the reproduction of music by. the given instrument in the perfect manner which is'obviously the desire and aim of every musician andmanufacturer. To obtain this result, the improved generator, hereinafter described, is essentially encased within means adapted to inclose all operating noises and to effectively prevent the assage of sound from the motor outwardly through either the intake or the exhaust opening of the generator. f

Possibly only secondar to the necessity for absolutely damping all vibration set up by the motor of the vacuum-generator is the great desirability of providing for the automatic compensation b the vacuum-generator for rapid and wi ely varying rates, at which the constantly changing cross-sectional area of 'the total number of exposed apertures in .the tracker-board, permit a widely varyingy flow' of air to `relieve the vacuunrwhich must be constantly maintained, with as little variation'in degree as 95 ma be possible. o accomplish this result, it has been found that a series-wound motor is admir- -ably suited to the Work, with the result that when the flow of air through the trackerboard increases, thus increasing the load 1- upon the motor, the latter automatically decreases its speed in accordance withA certain electro-magneto characteristics which ,such

edly a decrease inthe rate at which the vacuum is generated, and with the result that a constant 'pressure for all intents arid 'il l purposes is maintained.. t

' Still another, advantage gained by thefus'e 110 of a series-wound electric motor resides in the fact that, if roperly constructed, it 1s substantially equa ly well adapted to run on either direct or alternating current without these details there being that of a multiple fan unit operative to repeatedly act upon the air passing through its blades; a careful shaping of the air passage-ways in `order to offer to the aircurrents the least possible obstruction to their free passage through the disc; flanges over-lapping the fan-blades and adapted to thus' seal against air leakage in the spaces between the relatively movable and stationary parts;l channels so arranged as to permit a portion of the air to pass between the armature and-field-magnets in or' der to maintain a low temperature of the same;l certain details in the design of the electricwound-motor employed to produce the power for driving the vacuum-creating fans, readily assembled and disassembled; means to strain all dust and other foreign particles from the air passing into the device; improved automatically lubricated anti-friction bearings for supporting an improved tubular shaft; a vacuum bleed valve operative to constantly permit a 'predetermined minimum flowof air through-the machine for maintaining a low temperature of the motor, and to permit rapid yet delicate degrees of alteration in the air-pulling power of the device without depending for variations of different speeds ofthe motor; to provide av mechanically simple method of i manufacturing the device; andto provide numerous other details in the construction ,of thelpower .pla

and operation of the generator as hereinafter fully described in the 'following specification, when read in conjunction with the accompanying drawings,

ferred embodiment of the invention; Fig. 2

Ais a yhorizontal section on-the line 2--2 of Fig. 1; Fig. 3 right piano showing one of the improvedV is an end elevation of an up'- powe'r plants attached to' and supported by the rear side thereof; Fig.V 4 'is a rear elevation of the same; Fig. 5 is a similar view to Figzf-'showing by dotted lines the position t when operated within a p iano'; Fig. Gis a plan viewV of the interior Y. of'4 the fan casing,

Y blades Fig."v 7 is', an "enlarged fragmentary showing the stationary in which Fig. 1 is a. v vertical diametrical' section through the preelevational view of the upper 'part of the casing of the device, showing the vacuum bleed valve; Fig. 8 is a rear elevation of the said valve in the direction of the arrow 8 on Fig. 7 Fig. 9 is an enlarged fragmentary sectional view of the revolving fan bearing; Fig. 10 is an enlarged fragmentary -sectional View showing the sound-insulating supports of the motor and fan casings; Fig. 11 is an enlarged detail sectional view of a modification of the lower shaft bearing.; Fig. 12 is a section on the line 12--12 of Fig. 11; and Fig. 13 is a detail of a modified thrust bearingfor the shaft.

eferring to the drawings, there is provided an uppercylndrical casing section 1, closed at its upper limit by means of a horizontally extending imperforate wall 2,

and at its lower portion provided with a radially outwardly I directed peripheral fiange 3. The lower portion of the inclosing casing comprises a .cylindrical section? 4S, which is normally secured by any suitable means 5 to the flange 3 of the section 1, while the sides of said lower section are at their lower extent directed diagonally inwardly at 6, and centrally closed by means of a horizontally extendin wall 7, said wall, however being provi ed with spaced apertures 8. '`he inner surfaces of the sections 6 and 7 are covered by a relatively thick layer of fibrous material 9, which is also provided with spaced apertures 10 registering with upon the upper portion upper flanged portion 16 of an inner cylindrical sheet-metal shell 17, which, adjacent to its uppermost limits, is provided with spaced apertures 18, and at its lower limits is closed by a frusto-conical section 19, conforming in general to the shape of the adj acent portions 6 and 7 of the surrounding casing and spaced equi-distant therefrom.

Resting directly upon the bushings 15 and n shell iianges 16 are spaced sound-insulating sections of yielding material 20, upon which directly rests the reduced radially extending peripheral flange portionv 21 of a substantially' plain casting 22, 'centrally apertured at 23 and surrounding the lower edge portion 0f said aperture provided with a depending annular flange 24, while integral with the portion 22 and surrounding said aperture is an upwardly extending cylindrical section vided with ya centrally ositioned upwardly v extending integral cylindrical portion 30, adapted to serve as an oil reservoir and normally closed at its upper end by means of a removable cap or plug 31.

. The 'wall 28 is furthermore centrally provided with an upwardly extending integral y boss 32 provided with a central axially extending bore 33, forming a bearing for the tubular shaft 34 extending revolvably therethrough. The bore 33 is enlarged and internally threaded at 35 to receive a plug 36 shapedv as an inverted cup and housing a ball 37, which is larger than the bore of the shaft 34 and is seated within the end of said last-named bore. The plug 36 is provided centrally with a tapped bore 38, through which extends a flat-ended set-screw 39,which vin tur-n is surrounded adjacent to its outer end portion by means of a lock-nut 40. The boss 32 is also provided with a capillary diagonally extending bore 41, adapted to convey a predetermined amount of lubricant from they oi1-cup 30 into the bore 33 for lubricating the shaft-34 in its bearing. A

^ The wall 28 is furthermore provided upon its under surface and concentric with -the bore 33`with a centrally disposed rece 42, in which is forced a washer 43, loosely surrounding the shaft 34 but conforming within the recess, thus inclosing a suitable section of fibrous absorbent material 44 adapted to prevent the lubricant from passing in any substantial amount down the shaft to the commutator 45 of the electricA motor, which 'comprises field-coils 46, w-ithin which is revolva'bly mounted an armature 47, While suitable brushes 48 are 'su ported by brushholders 49, and said fiel -cOils are axially positioned with respect' to the rotating armature by means of radially .directed set-screws '50 extending through the cylindricalportion 25 of the casting22. l

,Suspended beneath the casting 22 and secured thereto by any suitable means 51, is a cylinder 52,v which co-operates with a shoulder at the base of the fiange 21 in order to position said cylinder exactly concentric with the said casting 22. The lowermost portion of l said last-named cylinder Y is spanned by means of ribs 53 1n order to provide` spaced laterally directed openings 54, while depending from the center of said ribs is an inverted cup-shaped lubricant reservoir 55 normally closed by means of a plug 56,`

while disposed within said reservoir and forming an integral extension of s aid ribs is a depending boss 57 provided with an axially positioned bore 58 which forms a bearing for the lower end portion of the tubular shaft 34.

At its upper extent, the bore 58 is enlarged placed a section of fibrous absorbent material 60, retained in position by means of a washer 61 secured by a forced fit into the said lastnamed aperture. Downwardly, the bore 58 is enlarged and internally threaded at 62 to receive an internal cup-plug 63, which is centrally drilled and tapped to support a set-screw 64 having a fiat upper end and supporting a ball 65, similar to the ball 37, and against which the tubular shaft directly co-operates. The set-screw 64 is furthermore surrounded at its-lower end portion by a lock-nut 66,l in'order to prevent the set-screw Y from accidental dislodgment.

The cylinder 52, immediately above the laterally directed apertures 64, is rovided preferably with an annular sho der67, upon which rests a transversely extending annular partition68, which Iis maintained in normal fixed position by means of radially directed set-screws 69, and is provided cento provide an annular recess 59, in which is 4 trally with an aperture 70, surrounded at its` immediate lower peripheral edge portion by a depending flange 71.' This partition 68 is provided withl a plurality of upwardly extending/stationary blades 72, each starting from the aperture 70, and as it progresses radially outwardly vbeing curved in a clockwise direction, for a purpose hereinafter described. l i

Mounted uponthe lower portion of the tubular shaft 34 -is a hub 7 3, provided with a radially extending plane fiange 74, upon the upper surface of which are secured spaced vanes or ribs A75 and 76, said vanes being preferably designed so that the latter extend downwardly from said hub to the periphery of said flange, while the former vanes extend to theperiphery of said flange from points spaced from said hub. This construction,`together withA the disc 77, formmg a shroud and connecting the upper free edge portions of said vanes, comprises a centrifugal fan or blower unit, whichvupon its under side is preferably provided with an axially positioned recess 78, into which extends a nut 79, operative to secure the said fanunits upon the shaft 34, and positioned opposite to though normally spaced from the washer 61. The shroud 77 is centrally apertured at 80 to admit air into the spaces between

tlie vanes

75 and 76 from the region above the horizontally extending partitions 68, as it passes through the aperture '70 in said partitions.

A second 'blower unit is likewise vsecured to saidshaft in any suitable manner, and is positioned between the unit first described and the armature of the drivin -inotor, said unit comprising a hub 81, W ich extends and contacts with the hub 73 up to the armature above referred to, and is provided substantially mid-way its longitudinal measurev with those hereinbefore described as comprising portions of the first fanjunit, and these v'anes 85 are connected at their upper free edges -by means of a shroud 86.

This device, as before stated, is preferably driven b the series-wound electric motor hereinbefore described, and to whichV current may be led in any suitable manner as by means of wires 87, which pass through the outer casing of the device in any suitable manner as by means of the insulating bushin 88, with which is adapted to be removab y connected the terminal 89 of an electric-conductor leading from any suitable source of electric current,'either alternating or direct in character. f

The upper casing section l is furthermore provided with a relatively large aperture 9 0, in which is fixed in any suitable manner a short tube 91, to which is coupled a preferably flexible section of hose 92, adapted to convey air from the operating parts of the piano 93 to the improved vacuum-creating device forming the invention. The tube 91 has removably securedin it 'a suitable section of mesh 94;, operative to strain the ain i' entering the device and prevent dust and other foreign particles from being conveyed to the finely machined mechanisms thereof. Supplementing this strainer, there is preferably provided a mesh section 95 in the form o a cap adapted -to surround and yieldingly engage the outer surface of the cylindrical portion 27 ofthe motor-casing` and again strain the incoming air before it passes into the motor and lower mechanisms by wa of theapertures 29. As to the position vt at this device occupies in practice, the' same may be upon suitable brackets 96 and'flexible supports 97, extending outwardly and downwardly from the back wall of a 4 piano as shown in Figs. 3 and 4, or the device may be supported within the piano as` shown by the dotted lines in Fig. 5 and by means of the same type of flexible members 97. y

The motor in this device is necessarily of Y that type which comprises a very high-speed as one of its characteristics. This feature secondarily 'implies a tendency of the motor to heat-up when run for a,prolongedperiod unless provided with enough circulating air to maintain a low temperature of the same. To this end, the upper portion of the casing 1 is provided with spaced apertures 98, in registry with which is positioned a similarly apertured section 99 of air insulating material such as leather, which device to sepai rate from said casing a'similarly apertured -circular disc 100y is revolvably mounted with respect to the apertures 98, and in a plane transverse to the axis of said aperture about a pivot 101, which is secured. to the casing and passes revolvabl 'through said disc, which latter is provi ed upon one side of its periphery with a laterally extending lever 102, to which is connected a flexible operating member 103, while intermediate of vthe limits of said lever the same is provided with oppositely extending ears '104, bent downwardly at their end portions to form parallel shoulders 105, through which are adjustably mounted screws. 106, held in fixed position 'by means of lock-nuts 107. These screws; being directed towards each other, co-operate with a suitable pin 108 positioned between them and extending outwardly from the casing member 1, and said pin and adjustable screws operating toV limit themovement of the valve-disc 100 in opposite directions, said disc being maintained in apredetermined position by means of a suitable spring 109 applied thereto in Vany, feasible manner. y

It will be noted that in the position of the disc, as shown in Fig. 7, there is always a predetermined amount of air being admitted 4 through the bleed-apertures 98 in order to maintain the necessary/ air circulation for cooling the motor, even' when the greatest amount of vacuum is desired to be maintained lfor the heaviest work in operating a reproducing musical instrument .to which the device is attached.- This arrangement also affords a simple eliicient and quickcomplete register, in which position air is admitted freely to the interior of the casing of the device, and thus indirectly decreases the degree of vacuum to such an extent that a relatively low pressure i`s available through the pneumatics of the muslcal instrument, thereby producing reproduced sounds of .as low intensity as may be desired.v And,

further, for this condition of soft music, 'thel bleed valve just .described may be'suddenly closed, thus effecting a rapid increase inthe ,vacuumto the maximum degree, or as near thereto as may be desired, which has the effect of creating the so-called crash music, that is, the loudest and suddenly struck chords, when desired.

The phrase pneumatics of the musical instrument hereinbefore referred to, as well as the single concise term instrument employed in the claims, refer to the operating parts of an instrument, whether the pneumatics arev arranged to actuate the usual hammers to produce sound, or are so de-l signed as to control and Ainfluence the quality of the sound produced, but do not refer to inoperative parts such as the usual bottom and top air chests or equalizers which merely comprise portions of the air `conduit between the pneumatics and the power device, or more specifically the air propelling means thereof.

In order to strain the air entering this bleed-valve, it will be noted that a guaze cap 109 is provided, the same being adapted to be removably secured over the top of the major portion of the disc 10() and the apertures extending therethrough.

The modified form of the lower bearing for supporting the tubular shaft 34 is illustrated in Figs. 11 and 12, and differs from the bearing hereinbefore described in that the lowermost end portion of said shaft is.

internally threaded at 110 and is bifurcated by means of arallel slots 111, into which slides longitu inally the bridge portion 112 separating two segmental apertures 113 in a'disc 114, as shown in Fig. 12. A tool-steel washer 115 is forced into a recess 116 in the lowermost portion of the boss 57, and against this washer thus held stationary, revolves in slidable contact the hardened toolsteel washer 114, it being obvious that the pressure between said washers is adjustable by meansof the set-screws 117, extendin into the end portion of the shaft 34, an locked in osition-b means of a nut 118.

And refidrring to ig. .13, the hollow shaft 34 is shown as resting substantially vertically upon a hard metallic disc 119, adjustably supported by a set-screw 120, carrled centrally by `a plu 121 and fixed in position by means of a loc -nut 122.. The sai'd plug is cupped to preferably partially surround and position the saiddisc, and is removably threaded in the-lower portion of the boss 57 hereinbefore described, and through which boss is also journalled the shaft 34.

Having thus described my invention, what Il claim and 'desire 'to protect by Letters Patent of the United States is 1. The combination of an electric motoroperated vacuum genera-ting device, and a conduit ada ted to connect said device with a pneumatical y operated musical instrument, with a positively actuatedvalve operative to relieve at will the vacuum of said device `6t'r other than through said musical instrument.

'operated music reproducing *generating device,

3. AThe combination of an electric motoroperated vacuum generating device, 'and av conduit adapted to connect said device with a pneumatically -operated musicall instrument, 4with a spring-operated valve, manually operable against the tension of said spring to relieve the vacuum created by said device other than through said musical instrument'.

4. The combination of an electric motoroperated vacuum generating device, Aand a conduit adapted to connect said device with a pneumatically operated musical instrument, with a spring-operated valve having adjustable limits of movement, manually operable against the tension of said spring, to relieve the vacuum created by said device other than through said musical instrument at variable rates. A Y

5. The combination of an electric .motoroperated vacuum generating device, and a conduit adapted to connect said device with a. pneumatically operated mechanism, withA a spring-operated valve havin adjustable limits of movement, manual y operable against the tensionof said spring, to relieve the vacuum created by said device other thanl through said conduit at variable rates, said valve being set at its minimum limit to pass a definite amount of ai'r tocool the motor of said device.

6. The combination of a .pneumatically with jan electric motor-operated vacuum andmeans connected instrumenta with said device and operative toconstantly pass a fixed minimum amount of air to cool the motor of said device, and said meansl being adpated to relieve the vacuum created by said device at variable rates above said fixed minimum. I'

7. Thev combination `of al pneumatically operated music reproducing instrument with an electric motor-operated vacuum generating device, and means connected with said device and operative to constanly pass a fixed minimum amount of air to cool the motor of said device, and said means being manually actuated to relieve the vacuum created byA said device at variable rates above said fixed minimum, and automatil cally operative to return when releasedl tol wards and to the said ixedminimuln. Y,

8. A vacuum generator for pneu-matic music-producing instruments, comprising a container, motorand fan units, within and separated `from said container by sound-insulating material, a port in said container adjacent to said fanl unit, and a baffle member between saidl -container port and said fan unit, operative tosdecrease the sound escaping through said port, and sound-insulating means to position said bafile mem-` b'er in spaced relation from both said container and said fan unit.

9. A vacuum generator. for pneumatic music-producing instruments, comprising a j container, a, motor and a fan unit within and separated from said container by soundinsulating material, a port in said container, a baffle member spaced from and positioned. between said container port and said fan unit, and a baiiie-plate outside of and spaced from said contalner, said baffle-plate and said baiiie member co-operating with that portion of the container provided with a port to provide a circuitous path Vfor air passing through said port, to decreaseto a minimum the sound escaping through said port.

10. A pneumatic power generator, comprising a container having inlet and outlet ports, a baiie member covering the outlet port and spaced away from the adjacent side of said container, and a baille-platecovering "said outlet port outside of and spaced from said container. 'l l 11. The .combination of an electric motoroperated vacuum-generating device, and a conduit adapted to connect said device with a pneumatcally-operated mechanism, -with a valve having adjustable limits of movement andloperative to relieve the vacuum created by the device, resilient means tending to maintain said valve in one limit of its movement and manually operable', against said resilient means towards its'other limit of movement.

12. The combination of an electric motoroperated vacuum-generating device, and a conduit adapted to connect said device with a pneumatically-operated mechanism, with a' valve having adjustable.limits of movement and operative to relieve the vacuum created .by the device, resilient means tending to maintain said valve at one limit of its movement, and manually operable against said resilient means towards its other limit of movement, and said valve at one limit of vitsmovement admitting to the device a predetermined amount of air, to cool the internalmechanism'. j l i T13'. The combination of an electric motoroperated pneumatic power generator, and

a conduit adapted toconnect said generator with a pneumatically-operated' mechanism, with a valve having adjustableV predetermined llmitsl. of movement, and operative lto relieve the vacuum createdsby the generator lindependently of the `said mecha- ,mism

14. The. combination of a.A pneumatica-lly erating the power to actuatethe sound producing parts of said instrument, and a conl duit connecting said parts -to said means and providedwith an aperture, with means adjustable independently of the air pressure to vary the effective area o saidape'rture to permit air to pass through said first means in varying quantities without also passing throughsaid parts.

15,. The combination of a pneumatically operated music instrument, means for generating the power to actuate the sound producing parts of said instrument, and a conduit connecting .said parts to said means,

with an aperture 1n said conduit, and an adjustably positioned valve operative` to bypass air through said iirst means without also passing through said parts.

16. The combination of a pneumatically operated player-piano, means for generating the power to actuate the said'sound producing parts of 'said piano, and a conduit to conduct air between said piano and said means, with means in said conduit to admit a predetermined minimum v flow of air through said first means without lpassing through said parts.

17. The combination of a pneumatically operated player-piano, meansv for generating the power to actuate the sound producing parts of'said piano, and means interposed between said arts and said first means for allowing a pre etermined flow of air to pass through said first means without also passing through the'said sound producing parts of said piano.

18. The combination of ,a pneumatically operated player-piano, means for generating the power to actuate the sound producingy parts of said'piano, and a valve manually opened and closed and interposed between said parts and said first means for allowing air to pass through said first means without also passing through the said sound producing parts of saidpiano.

19. The combination of a pneumatically operated player-piano, means for generating the power ,to actuate the sound vproducing parts of said piano, and a manually operated valve, adjustable at will to permit air tol and said Valve also be- Y first `means'to permit air to pass through 130 said firstmeans withoutalso passing through said parts.

21. The combination of a pneumatically operated music instrument, means for generating the power to actuate the sound producing parts of said instrument, and a conduit connecting said sound producing parts to said means, with a valve manually adjustable at will to position intermediate of its limits of movement and operative to bypass air in var ing degrees through said first means wit out also passing through said sound producin parts.

22. The com ination of a pneumatically operated player-piano, means for generating the power to actuate the sound-producing parts of said piano, and a conduit to conduct air between said piano and 'said means, with means direct manually actuated and instantly adjustable to positions between its limits of movement and independently of the speed of operation of said first means, to admit air in varying quantities through said first ,means Wlthout passing through said sound roducing parts.

23.. he combination` of a pneumatically operated player-piano, means for generating the power to actuate the sound producing parts of said piano, and a valve directly actuated manually between open and closed positions for allowing air to pass through said Y first means without also passing through the said sound producing parts of said piano.

24. The combination of a pneumatically operated music player instrument, and means to generate the power to operate the sound producing parts of saidinstrument, with manually actuated means to instantly vary between maximum and minimum the effective operating power sup lied to said sound indepen ently of the power caslng provided with an inlet-and an outlet and surrounding said motor andsaid means, with means to maintain a predetermined minimum rate of flow of air constantly through said casing by a course other than through said inlet. A p

` 26. The combination ofa pneumatic power generator, comprisingv a motor, air propelling means actuated by said motor, and a casing provided with an inlet and an outlet and surrounding said'motorandv said means, with means to maintaina minimum flow ofiair constantly past the motor within said casingfby'a courseother than through said inlet. A

27. The combination of a pneumatic power nerator comprising a motor, air propel- ,ing means actuated -by said motor, and a casing provided withI an inletand an outlet and surrounding said motor andsaid means,

instrument, and means to adjustably relieve the vacuum of 'said mechanism in degrees varying at will other than through said instrument.

29. The combination of a pneumatically operatedlmusical instrument, with a vacuum generating mechanism, comprising an air propelling means, a motor to drive said means, a container common to said means and said motor, a conduit connecting said air propellig means to said instrument, and manually actuated means to permit a quantity of,air variable at will to pass through said mechanism other, than through said instrument.' L

30. The combination of a pneumatically operated musical instrument, with a vacuum generating mechanism, comprising an air propelling means, a motorl to drive said means, and a container common to said means and said motor, a conduit connecting said air .propelling means to said instrument, and means having adjustablel limits to relieve the vacuum of said mechanism other than through said instrument.

31. The combination of a pneumatically operated musical instrument, with a pneumatic power generating mechanism', comprising an air propelling means, a motor to `drive said means, a container common to said means and said motor, a conduit cnnecting said air propelling means to said instrument, and resiliently controlled means to automaticallymaintain a minimum quantity of air passing through said mechanism without its passing through said instrument, to cool said motor.

32. The combination of a pneumaticallyoperated musical instrument` with a pneumatic power generating mechanism, comprising an air propelling means, a motor to drive said means, a container common to said mea-ns and said motor, a conduit con` necting said air propelling means to said instrument, and resiliently controlled means having an ,adjustable limit of movement to automatically pass a predetermined mini- -mum quantity of air through said mechanismrwithout its strument.

33. The combination of a pneumatlcally passing through said inoperated musical instrument, with a pneumatic power generating mechanism. comprlslng an a1r propelling means, a motor to drive said means, a container common to air inlet in the upper portion of the container, a casing within the container, the

outer walls of which are 'spaced apart -from the. innervwalls of the container, an apertured battle plate between the lower portion ofthe container and the. lower portion of the casing, a compressible gasket interposed between the baflie plate and the lower por-l tion of the casing which .forms an air chamber between the baille and the lower portion.-

. ofthe casing, @plurality of rotary fan blades within the lower portion of the caslng, la plurality of vanes also within the lower portion of the casing, an electric motor within the upper portion of the casing,

which rotates the fan blades, and cushioning devices interposed between the linner walls of the container and the' outer walls 'of the casing.

35. A suction-producing apparatus of the class recited, infwhich are combined, a container inclosed at the top and open at the bottom, an air inlet in the top of the container, a casing within the container, the

-outer walls of which are spaced apart from the inner walls of the container, a plurality of fan blades withinthe lower portion ofthe casing, a plurality of'vanes also within the lower portion of the said casing, an electric motor within the upper portion of the casing, which rotates the fan blades, supporting devices within the' container upon which the casing rests, cushioning devices interposed between the inner walls of the container and the outer walls of the cas-`- ing, and' cushioning devices between thesupporting devices and both the inner walls of the container and the outer walls of the casing.

36. An air propelling mechanism, comprising a container having an inlet and an outlet, a unitary casing removably supported within said'container, and having an inletand an outlet, an air propelling means within said casing, a motor also with-in said casing to drive said means and so situated thatthe said means creates a draft of fresh air' passing over the parts of said motor to cool the same before being said means. Y

acted upon by 37. An air propellingjmcchanism comprising a container having an inlet and an outlet, a casingwithin said container, and having an inlet and an outlet, sound insulating rmeans to support the weight of said casing with respect to said container and operative to divide the interior of said container outside of said casing into a plurality of compartments containing -air at different pressures.

38. AThe combination of an electric motoroperated pneumatic power generator, and a 'conduit adapted to connect said generator with a pneumatically-operated mechanism, with a valve having a normally fixed range of movement, and means to adjustably alter the limits xing said normal range, said valve being operative to relieve the air pres` sure created by the said generator independently of the said mechanism. l 39. A pump, comprising a casing, a surrounding container spacedaway from direct contact with said casing, and an air-tight partition of flexible vibration-absorbing material yieldingly gripping and surrounding a portion of said casing and extending from said casing to said container to divide the intervening space into a plurality of chambers adapted to contain air at different pressures.

40. The combination of a casing, with a surrounding container having asupporting surface, and agasket resting upon said surface and,- also resiliently engaging a por- "tion "of the radially outer surface of said casing to form an air tight partition to dim'de the space between said casing and said container into a. plurality of chambers.

41. The combination of a casing and a fan and motor todrive said fan inclosed within ysaid casing, with a surrounding container having a supporting surface, and a gasket resting upon said surface and also co-operating. with said casing to form an .air-tight partition to divide the space between said casing and said container into a plurality of chambers'adapted to contain air at dierent pressures.

42. The combination of a unit pump casing, with a unit sectional containery independent of said casing, and a yielding 'gasket contacting with and extending from Vsaid -licasing into contact with and secured 1n position by the union of the-sections of said container.

- 43. The combination of a unit pump casing, with a unit sectional containerindependent of saidfcasing, anda vibrationinsulating gasket 'having one portion airtight relation with said casing andhaving. another portieri air-tightrelationl-'With a section of Asaid container and operatively compressed against said casing. by the union of said sections. l v f n, 454:.v The combination of apump casing,

with a container, and a vibration-insulating gasket having one portion in direct cov-operation with said casing and having another portion in direct co-operation with said container to form an air-tight partition dividing the space between said casing and said container into a pluralit of chambers adapted to contain air at di erent pressures.

45. The combination of a pump casing, with a sectional container,one of said sections having a longitudinally facing sub-l stantially radially extending surface, and a gasket comprising a pair of annular members, one o which bears against said surface and connects the adjacent container section with said casing, and the other of which members bears against and extends between the other container section and said casing.

46. The combination of a pump casing, with a sectional container, one of said sections having a longitudinally facing substantially radially extending surface, and a gasket comprlsing a pair of annular mem` bers, one of which bears against said surface and connects the adjacent container section with said casing, and the other of .which members bears against and extends between the other container section and said casing, said gasket member uniting to form a yiel ing vibration-insulating air-tight partition between said casing and container, and operatively positioned by the union of said container sections. i

47. A pump, comprising a casing having an inlet and an outlet, a fan and motor unit mounted within and surrounded by said casino', a surrounding container also having an in et and an outlet, and a gasket operative to support said casing within said container and to divide the intervening space into a plurality of chambers, said fan within said casing being operative to force air into said container upon one side of said gasket, within the space 'between said casing and said container, thence through said casing, and then outwardly into the space between said casing and said container upon the other side of said gasket. y

48. A vacuum generator for pneumatic music-producing instruments, com rising a container, motor and fan units w1thin and separated from said container by sound-insulatln' material, said container being provide with a port adjacent to said fan unit, and a cup-shaped baille member between said container port and said fan unit, operavtlve to decrease the sound escaping through said port, and sound-insulating means to, position said baille member in spaced relaf tio'lti.J from both said container and said fan um A vacuum generator for pneumatic music-producing instruments, com rising a contalner, motor and fan units w1thin and separated from said container by sound nsulating material, said container being provided with a port ad'acent to said fan unit, and a cup-shaped ba e member between said container port and said fan unit, said cupsha d baille member partly surrounding sai fan unit, and operative to decrease the sound escaplng through said port, and sound-insulating means to position said bafiie member i'n spaced relation from both said container and said fan unit.

50. The combination of a pneumatic power generator, comprisinga motor, air-impelling means actuated by said motor, and a casing provided with an inlet and an outlet and surrounding said motor and said air-impell- 8 0 ing means, said casing being provided with an aperture to permit a ilow of air through said casin b a course other than that between sai inl'et and said outlet.

51. A suction producing apparatus which comprises in combination, a container having an inlet and an outlet, a casing within the said container, the outer walls of which are spaced apart from the inner walls of the said container, a baille member between 9o4 the lower rtion of the container and the lower portlon of the casing, a plurality of rotary fan blades within the lower portion of the casing, a plurality of vanes also within the lower portion of the casing, an electric motor within the upper portion of the cas' ing which rotates the fan blades to draw the incoming air past said motor to cool the same, and cushioning means interposed between the inner wallsof the container and 10o the outer walls of the casing.

52. A suction-producing apparatus of the class recited, in which are combined, a container havin an inlet and an outlet, a casin within t e container, the outer walls of'1 105 wlich are spaced apart from the inner walls" of the container, a pluralit .of fan blades within the lower portion o the casing, an` electric motor within the upper portion of the casing which rotates the fan bladesto 1 10 draw air past said motor, su porting means within the container upon w ichthe casing rests, cushioning means inter osed between the inner walls of the container and the outer walls of the casing, and cushioninv means between the supportingmeans an both the inner walls of the containerand the outer walls of the casing. i

53. In a device for operatingthe pneumatics of a player piano, the combination with a container, a m`otor and fan suction unit within said container for drawing air through the pneumatics 'of a piano, said motor and fan being mounted upon the same* shaft, and a pneumatic expression mechamsm v-for varying the pressure of air passi@ through the fan element.

54. An air propelling mechanism for pneumatically operated pianos, "comprising -a container having a main-*inlet and an outcontainer having a plurality' of inlets and an outlet2 a unitary casing entirely Within the container and supported by sound deadening material, and having an inlet and an outlet, a fan and motor Within saidcasing, and means to maintain a current of airflowing over the parts of said motor to cool the same, said current of air passing. through the motor before it passes into said fan to be acted upon thereby.

In testimony whereof I have ailixed my signature.

STANLEY S. CRAMER.