US879738A - Bellows for automatic musical instruments. - Google Patents

Description

PATENTED FEB.18, 1908.

M. CLARK. BELLOWS FOB. AUTUMATIO MUSICAL INSTRUMENTS.

, APPLIMT'ION H'LED 1350.19. 1902. RENEWED NOV. 14. 1904.

rizegsr arcs.

MELvrLL omnnpr CHICAGO, ILLINOIS.

BELLOWS FOR AUTQMATIG HUSECAL INSTRU'EE'EIZTS.

Specification of Letters Patent.

Patented Feb. 18, 1908.

Application filed December 19, 1902- $crial No. 135,898. Renewed November ls. 1904:- Serial No. 2321585.

This invention is designed to afford newand improved means tor operating a pnen matic motor for actuating the perforated sheet in an automatic musical instrument or player in such manner that suchmotor, while deriving its power from the same source of air under tension, whether above or below atmospheric, as that which crates the neumatics whose action is con'tro led by the perforated sheet, shall nevertheless derive a speed independent of the volume of air required for operating the pnenmatics; so that, whether the music is 'to be played softly or loudly, the speed may be unvarying unless it is varied at the will of the performer by means of the devices provided for that purpose.

It consists in the features cf construction set out in the claims.

In the drawings z-Figure 1 is a longitudinal vertical section of a portion of a player for a musical instrument having my improvement in the devices for operating the pneumatic motor.. Fig. 2 is a section'at the line, 2--2, on Fig. 1.

I have shown, without going into details, the main crank shaft and motor bellows or pneumatics operating it, constituting the op erating devices of the pneumatic motor for actuating the er-forated cont-rolling sheet, these elements eing of construction which is more or less familiar and which is not concerned in the present invention put only associated therewith. These parts will therefore be described only in general for the urpose of assisting the understanding of t ose parts of the invention which cooperate with them. I

Triple-crankshaft, 1, has its three cranks, 2, 3, and 1, connected with the three motor neumatics, 5, 7, respectively; and it may be understood without further explanation that by proper mechanical connections the crank-shaft drives the rolls, 8, 9, tor actuatvalve, 12, is located, which may be operated at the will of the performer, ,by means not shown, when it is desired. to vary the speedof the perforated music sheet. The purpose of the present invention is topreserve such speed 1mchanged unless it is" modified by c ening or closing the valve in'said valve caamber; and in order that there shall. ,be no variation of the speed unless it is ei'l'ectedhyadjusting said valve, it is necessary that the tension of the air Whose communication with the motors is control-led by said valve be maintained constant. For purpose I provide a bellows, 13, which-is held normally distended byv meansof a spring, 14, which communicates through. a duct, 21, and pipe,

22, with the valve chamber, 11, and thereby with the motor neumatics, 5, 6, 7 and whic" is in communication through a duct, 15, with.

the bellows, 16, which is connected by the throat, 16*, with the pneumhtics which 0. erate the playing orsound-control'ling devices. These latter pneumatics and playing devices are not shown but may be unde stood to be of any customary form and construction. This bellows, if), is normally distcnded by a spring, 17, and is collapsed against the ten sion of the spring by the action of the pumpers, 19, operated by pedals, 18, thecust0mary manner. The spring, 17, is of suitable strength to require for its compression the exh austion of air from the bellows, 16,to an extent suitable for the maximum intensity of action of the playing or sound-controlling devices,-th-at is to say, so that the loudest tones may be produced of which the instrument is capable. For example, in an ordinary piano player this spring will be what is termed a 40 pound spring, that is, it will require such rarefaction of the air in the bellows that the dilierence between the interior tension and the atmospheric pressure 11. on the whole exposed area of the nloving We of the bellows will amount to 40 pounds; thus, if the bellows area is 120 square inches, the

' lightest act1onthatis,rthe action necessary to produce-the softest tones of which the in struinent is capable-the pumpers will be foperated scans to compress this spring to a tension of; from to pounds.

the-instrument is being operated for-playing, therefore, there will be not less than 1 5 pounds tension von this spring. 'Theduct, 15, which affords commlnncation between the two bel- ;l'ows,';13, and 16',is of sufficient size to render such communication entirely free, so that f5 whatever the air-tension maybe in the b'el-' ,lows, 16,-it willfbe-experienced also in the bellows,';-1 3, the absence of any means to restrictor close this communication. The. spring, t4, which operates to hold the bellows, 13,d1ste nded, and which is com .Eres'sedfby the-"rarefaction-of the air in the ellow's, such as, willoccur'wheneverit is in free' communication with the bellows, 16, whenthe, 'umpers" are being "operated to playing devices, is'so much lighter mpropor- \tion to the area ofthe bellows which 'itcontrols than the spring, 17, of the other bellqws,

" that said bellows, 1-3,.is 'collapsed'to the utmost-before the bellows, 16,- is collapsed suflir-ciently to develop from the spring even the minimum tension of 15jpounds which is nec-' essary to the lightest actionofthe laying devices.-' The duct, 15, opens into t e bel- '-lows,' jl'i*lv throu h a fixed wall of said bellows, "and the op osite oscillating wall-carries. a

valve,- 20 ,1 a' a ted to seat at the mouth of the duct-- 'whenf e bellows. is collapsed. This valve is mounted upon a spring, 23,;which {lelds when the 'fvalv'e, inthe colla se of the I encounters the margin of t e mouth lof the duct, 15, so that during the very slight [leakage that will occur around the valve before it, is; sufficiently pressedu on its seat to isl 'elose the passage of-air, the co apse continu- "'ing, the spring. will be slightly compressed.

fThe vresult of this construction is that when- "ever, in the operation of the pumper, the rare- ;faction of the; air in the bellows, 13, has been carried to the 'degree necessary to compress its spring andoollapse it until the valve reaches its seat and closes the mouth of the I duct, 15, no further rarefaction can take place, and the subsequent "action of the Y ers will develop the proper degree of rareaction in the other bellows to 'adapt them to operate the playing devices to any extent that the operator desires; and whatevertension may be developed in the bellows, 16, by subsequent actlon of the pumpers,

- .even up tothe maximum of 40 pounds, to which the spring of that bellows ma be cal- :culated, the tension in the otherbel ows, 13,

' cannot-be increased; and as the air is adinto that bellows in operating the mo-,

Whenever r continue as long as the instrument is in use,

valve, 12, but for any given position-0f that f valve it will be uniform without regard to the rate of action of the pumpers, which. will be vvaried accordin to themtensity of action rarefy the alr' in'that' bellows and operate-the the bellows, 13, being, for example, half that the other bellows for operating the playing erating the playing devices.

tor pneumatms, 5, 6 and 7, to drive the rolls andwpropel the lperforated sheet, the bellows expands slight y under the action of its spring and unseats the valve, whereupon immediately thesuperior'tension in the other bellows o crates to collapse the bellows, 13, again an close the valve;'and this 0 eration of opening and closing, to the very east extent which will admit air past the valve, will 7 5 the variation of tension in the bellows, 13

being -'im erceptible,although, sufficient to alternate y seat and'uns'eat the valve. The uniform tension which thus results in the bellows, 13, gives uniform action to the motor neumatics and-the mechanism which they rive for propelhng the perforated sheet. This operation may be more or less. rapid according to the adjustment of the controlling desired in the p 'aying devices. The area of I of the bellows, 16, a 5 pound s ring in the smallerbellows will be collapse when the rarefaction in the larger bellows is sufficient tov develop a 10 pound tension in the spring of that bellows; and the minimum tension fwhich will cause the playin devices to 0 erate for the lightest tone bemg 15 poun s in that bellows, the maximum tension in the smaller bellows will always be maintained 1 whenever the instrument is o erated for laying. ,It will-be understood tiiat Ido not mit myself to an recise relations between the areas of these ellows'or between the tension of their springs or whatever other means are employed to hold them expanded; and infact, inasmuch as the lightest music is usually played in slower time, requiring less rapid action of the motor which propels the perforated sheet, very satisfactory results may be obtained even when the bellows which 0 erates these motor, neumatics is adjuste so that it is fully c llapse'd only by a tension greater than minimum tension necessary in devices; but the most satisfactory construction and that which embodies most fully the principle of my invention is that herein indicated, in which the maximum tension of the motoro eratingbellows is not greater, and practica ly somewhat less, than the minimum tension necessary in the other-bellows forop- It will be seen also, upon consideration, that the result described is dependent upon the governing valve, 20, in the motor-o crating bellows, because if there were no 'va ve or equivalent means for shutting off communication between thetwo bellows when-the lighter bel lows is colla sed, vigorous action of a. the pumpers wou d draw the air through the the structure shown in the drawi munication for exhausting both 0 -lighter bellows precisely as if it were a mere duct, and the actionof the motor pneumatics for perating the erforated sheet would, in effect, he produce directly by the larger bellows, with the result that the speed would vary according to the tension maintained in that bellows. The essential feature, therefore, of my invention is the valve, 20, or an equivalent device; and the relation between the. ower of the distending springs of the two ellows is only a secondary feature.

-It will be manifest, upon consideration, that'the principle of my invention is not limited .to an exhaust bellows, either for operatingthe playing devices or the pneuqmatic motor, and I em loy theterm tension, referring to the egree of rarefaction of thejair in the exhaust bellowsemployed in s, to indicate broadly, any difference whic may exist between atmospheric tension and the tension within the bellows, whichever be the greater. I The modifications in details of the structure which would be necessary to adapt the invention to an instrument employing (ioiiipressed instead of rarefied air will be obvious to any one skilled in the art.

The bellows shown in the drawings constitute an air chamber in which the tension ofthe 'air' is abnormal or unatmospheric, and tl'i'iais theessential characteristic and quality orachamber or chambers for the purpose of the present invention. The s ecific mechanical construction of the chamber by which it is collapsible and expansible has only specificconvenience' and utility; butmy invention generically considered isnot limited to this'specific'mechanical feature, thou h it is forkcertain reasons preferred and c aimed specifically.

I claim In an automatic musical instrument in combination with two exhaust chambers for different purposes, an exhauster havin corrasai chambers; means for closing by the collapse of one of said chambers the port of commu- 'nication through which such chamber is exhausted, said means including a valve con structed to be seated simultaneously over substantially the entire extent of its seat.

2. In an automatic musical instrument in combination "with two exhaust chambers,

i one for operating the playing devices and the other for a supplemental purpose, an exhauster which operates to exhaust both said chambers; means for closing by the collapse of the supplemental chamber the windway or port through which it is exhausted, said means including a valve constructedto be seated simultaneously over substantially the entire extent of its seat.

In an automatic musical instrument, an exhaust chamber for receiving air from the devices of the instrument; an exhauster for exhausting the air from such chamber,

means for closing by the collapse of said chamber the windway or port of communi cation through which it is exhausted, said means including a valve which is constructed to be seated simultaneously at substantially the entire extent of its seat, and a siring which is compressed'in the seating ot the.

valve.

4. In'an automatic musical instrument, a neumatic motor; an exhaust chamber or ellows for o crating such motor; an eX- hauster for ex austing such bellows; means for closing by the collapse of said bellows the port of communication through which it is exhausted, said means including a valve constructed" to be seated simultaneously oversubstantially the entire extent of its seat.

5. In an automatic musical instrument, in

combination with a pneumatic motor, an exhaust chamber or bellows for operating it; an exhauster for exhausting the air from said bellows; means which control the windway or ort of communication through which the bel ows is thus exhausted adapted for closing the same upon the approach of the tension in said bellows to a predetermined maximum and opening it upon recession from said 7i In an automatic musical instrument in combination with an exhaust air chamber .for operating the laying devices; a second exhaust air cham er for an auxiliary purpose, both, said chambers being provided with means for limiting the air tensionwhich can be produced therein, the maximumtension of the second chamber being not greater than the minimum tension necessary in the first air chamber for giving the playing devices the lightest action; an exauster connected for exhausting both said chambers; means for controlling the port through whichthe second chamber is exhausted, including a valve which is moved toward its seat by approach to the maximum of the tension In said second chamber and-moved from its seat byrecession from 1 such maximum, such valve being constructed to be seated and unseated simultaneously over substantially its entire seat.

8. In an automatic musical instrument in combination two exhaust chambers for different purposes communicating with each other, a valve in one chamber controlling l my hand, in the presence of two witnesses, said communication adapted for closing upon at Chicago, Illinois, this 13th day of Decemapproach of tension in said chamber to a reher, A. D. 1902.

determined. maximum and constructe to MELVILLE CLARK. 5 be seated siinultaneously over substantially In the presence ofthe entire extent of its seat. CHAS. S. BURTON,

In testimony whereof I have hereunto set FREDK. G. FISCHER.

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