US1027257A - Pneumatic action for self-playing pianos. - Google Patents

Description

W. A. KRUGK.

PNEUMATIC ACTION FOB SELF PLAYING PIANOS.

APPLICATION FILED APR. 27, 1911.

Patented May 21, 1912.

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0Q K H wue wto'c 1 This invention consists of certain cylinder and piston devices, usually. of metal, and,

To it'may wnnzrnnaa xnuc'xgor ca'mbnu, NEW JERSEY.

frnmmarrc nor-Ion r012. SELF-PLAYING- PIANOS.

Be it known that I, WALTER; A. Knock, citizen of'the United States,-.residing at Camden, in the, county of Camden and State of New Jersey,'have invented certain new and useful Improvements in Pneumatic Ac.

tions for Self-Playing Pianos, of .which'the O WiII is a specification. a

This invention relates Ito pneumaticjactions for self-playing pianos, and the like,

- and belongs withthat class of cont-rivances interposed between. the suction chamber common to all players actuated ,by atmoscylindrical valve operating pheric pre.

sure, and the mechanical piano a'c-tionfor striking the strings.

having special construction and special arrangement with respect to each other, whereby it is believed one or more of the customary bellows neumatics-are done away with for each-pianokey, and, the

whole apparatus thus rendered..i'elatively much more durable and lasting.

The Special Parts pr g this inyefi ti'on and their lent with respect to each other, are set out in theaccompanying drawings, of which trated in section, to disclose internal ele'- ments; Fig. 2 is an exterior view of the lower portion of the valve-operating cyl1n-- der, showing the relative positions ofi the" larger and smaller tubularprojectinpartsv thereof. Fig. 3 is a top plan view,.s owing; the interior of the lower portion of the valve-operatincylinder.

In all the views and in the following description, the Same letter of reference is used to designate the same..part..

' Considering Fig. "1', the suction-chamber is referred to by the letter'A, and a partlal;

vacuum 'is created and maintained therein by a suitable exhausting bellows B, con- "nected with the suction chamber, and operated by a treadle C. Secured upon the suction chamber, is the-lower portion D of the devices. The lower portion D has two, inclined projecting tubular parts, of which the larger tube E slants downwardly, and, the smaller tube F extends upwardly. A suitable connection G puts the large tubular projection E in communication with the suction chamber A. Another pipe H, connects the smaller pro- Specification tit-Letters mes. hpplteatioaflled nn-i127, i911. Seria11i'o.623,614.

Figure l "represents-a sideiviewof all the; parts assembled, some of which are 1'lll1S+;

'fect'ive v o li'tssing t rough the bottom of the piston S 'is a small air ducts, to be again referred to. l r From the piston S, the valve. rod T extends upwardly through the nipple U, that jecting tubular portion F mentioned, with the tracker J. The upper portion K of the cylindrical valve operating devices, is best lllustrated'also in Fig. 1. It has an opening L in its top, bular'projecting part M. p v

The two cylindrical portions D and K are cup-shapeda-s shown in Fig. 1, the sides and bottom of each being in one piece. The portion D is inverted and its bottom is uppermost as the partsare assembled.-

It will be noted that the lower portion D PatentedMay21,1912.

and a downwardly-inclined tu of the cylindrical valve-operating devices,

and the upper portion K thereof, are provided at their months with internal threads i N and 0, 5nd that those threads hermit the 1 1. upper portion K and thelower portion D to be ad ustably joined by the coupling P,

threaded externally as "shown. And, the relative positions of the-coupling andthe portions of the cylinder connected by it,

Q, and R, actingv as jam nuts against the port'ionsD and K as illustrated in Fig. 1.

Within the lower portion D of the cylinmay be fixed by means of the two ring nuts drical valve-operating devices is located a piston S, usually, cup-shaped and made of the same metal as. theportion D, in order-to avoid binding due'to changes of temper- ;ature. The cylindrical P01111011 -'D is bored carefully interiorly,* and" the piston S is turned with equal care to fit it-fniovably,

without. packing, and as'closely asv the efrat-ion'of-the parts will admit.

is formed integrally with the coupling P, and the mouth of which, designated by the letter V, is formed as a valve seat for the .valve 2. By constructing thepiston'. S cupsha'ped as illustrated anddescribed, it does.

not wabble in the cylinder but movesdiing the valve rod T without special guiding '100 rectly up and :down, thus adequately vguidmeans therefor. It will be noted that the valve rod T is'threaded at its'upper end, and that the valve t is, therefore, adjustable on the rod. The nut employed to fix the position of the valve on the rod is marked W. As previously explained, and as illustrated in Fig. 1, the upper portion K of the cylindrical valve-operating devices, is provided with the tubular projecting part M, and, it will be seen, that the tube M is joined by-a pipe X to the air duct Y in a block Z, upon which is secured the actionoperating cylinder 1. The cylinder 1 is in communlcat-ion withthe duct as shown. Within the cylinder lis a cupped piston 2, made, usually, of the same material as the cylinder, to avoid binding due to changes of temperature. The cylinder 1 1s. bored out carefully, and the piston 2 is turned with equal care to fit the cylinder movably without packing, and as closely asthe efiective operation will admit. Piston 2 ordinarily has a guide rod 3 projecting centrally below it, and passing through a small hole 4 in the bottom of the cylinder. It is likewise customary to place a disk of felt next to the bot-tom of the piston 2, shown in Fig. 1 and marked 5, to cushion the blow' of the descending piston upon the bottom of the cylinder 1. On its upper side, the piston 2 is pivotally connected by the link 6, with the lever 7, of the mechanical piano action.

The operation of this invention may be explained by stating that the partial vacuum in the suction chamber being created and maintained, the air is exhausted directly from within the lower portion D of the cylindrical valve-operating devices through the larger tubular pro ection E,

which communicates with the portion D above the piston S. By way of the duct 8 the air is taken from below the piston S, and by way of the smaller tubular projection F, the air is exhausted from the pipe I-I connected with the tracker J.

It has been explained that the top of the upper portion K of the cylindrical valveoperating devices has an opening to the atmosphere, and, therefore, the suctlon keeps valve t seated upon the seat V of the nipple U. So long as the tracker is covered by the sheet in the usual manner, the partial vacuum will be maintained. An orifice 8 of the tracker being uncovered, air enters beneath piston S, raising the piston, and, consequently, valve t, which, being a doubleface valve as shown, closes the opening L in the upper cylindrical portion K through the top thereof, and allows the air to be exhausted from 'beneath the piston 2 in the action-operating cylinder 1, and operates the lever 7, of the piano action. It may be that the orifice 8 of the tracker is quickly opened and immediately closed, admitting but relatively little air beneath piston S. But, the piston S has considerably greater superficial area't-h'an valve t, and, therefore,

the pressure although it may be lower, raises the smaller valve against the pressure of the external air. The tracker orifice 8 being closed, the air admitted beneath the piston S is, very rapidly, taken away into the suction chamber, and the operation may be quickly repeated. In other words, the

.same note may be sounded as often as dewhat I'claim and desire to secure by Let- .ters-Patent of the United States, is

1. In a pneumatic action, the combination with upper and lower cup-shaped portions, said upper portion being inverted and having an opening in its bottom, of a coupling constructed to engage both of said portions adjustably, the said coupling having a nipple extending into said inverted portion and provided with a valve seat, pneumatic key-operating devices, tubular connections leading from said devices and opening into said inverted portion above said valve seat, a valve arranged to cover alternately said seat and the said opening in said inverted portion, a cup-shaped piston movably fittin said lower portion, a valve rod bearing said valve at one end, said rod being rigidly attached to and guided by said iston, a tracker, tubular connections leading from the tracker and opening into said lower portion below said piston, a suction chaimber, and tubular connections leading from the suction chamber and opening into said lower portion above said. piston.

2. In a pneumatic action, the combination with upper and lower cup-shaped portions, said upper portion being inverted and having an opening in its bottom, of a coupling constructed to adjustably engage both. of said portions, the said coupling having a nipple extending into said inverted portion and provided with a valve seat, pneumatic key-operating devices, tubular I connections leading from said devices and opening into said inverted portion above the valve seat,

a valve arranged to cover alternately said seat and said opening in said inverted portion, a cup'shaped piston provided with an air duct and movably fitting said lower portion, a valve rod bearing said valve at one end, said rod being rigidly attached to and guided by said piston, a tracker, tubular connection. leading from the tracker and opening into said lower portion below said, piston, a suction chamber, and tubular connections leading from the suction chamber and opening into said lower portion above the said piston.

In testimony whereof I affix my signature in presence of two Witnesses.

WALTER A. KRUOK;

Witnesses:

-WILLIAM P. WALSH,

EDWA D RICHARDSON.

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