US1274766A - Pneumatic piano-player. - Google Patents

Description

. C. E. PETERSON.

A PNEUMATIC PIANO PLAYER.

APPLICATION FILED IUNEZI. 1917.

1,274,766. Patente-Mug. 6,1918.

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CLAUS E. PETERSON, 0E WORCESTER, MASSACHUSETTS, ASSIGNCE, :BY MESNE ASSIGN- MENTS, To IvEESoN PIANO PLAYER COMPANY, oE'BoSToN, MASSACHUSETTS, A Con- PoEATIoNoE MASSACHUSETTS.

PNEUMATIC PIANO-PLAYER.

Specification of Letters Patent. Patented A110'. 6, 1918.

Application mea June 21, 1917. Serial No. 176,216.

Toallwwm it may concern:

Be it known'that` I, CLAUS E. PETERSON, a citizen of the United States, residing at lvorcester, in the county of Vorcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Pneumatic Piano-Players, of which the tollowing is a specification, accompanied by drawings forming a part of the same.

My present invention relates to so called bleed devices of a piano player and to an improved connection between the bleed device and the primary valve, which may be readily applied, and in which the use of rubber tubing Vmay be avoided. In the accompanying drawings I have shown so much of a pneumatic piano player as'will be necessary to illustrate the character of my present invention.

The piano player embodying my present invention is similar to those nowin com-y mon use, and comprises a motor pneumatic, a Secondary valve for controlling the action of the motor pneumatic, and a primary valve whose action controlled by the passage of a perforated sheet over the tracker bar. In the accompanying drawings,

Figure 1 represents a rear view of a portion of the player action. l

Fig. 2 is a sectional view on the plane of the broken line 2 2, Fig. 1, showing the arrangement of the motor pneumatic vand the secondary and primary valves. Other por-` tions of the player mechanism not concern ed in my present invention, and therefore not shown, will be well understood by those conversant with this class of instruments.

Fig. 3 is a detached view of the connection between the hollow bleed bar and the primary valve.

Like reference characters refer to like parts in the different figures.

My improved player action comprises, in the present instance, three bars 1, 2 and 3, extending lengthwise the instrument, preferably made of wood, and having attached to their upper surfaces Steel plates 4, 5 and 6. The upper bar 1 is shown in transverse sectional view in Fig. 2, to which reference is particularly made to illuStrat-ethe character of my present invention. rlhe wooden bar 1 is provided with longitudinal channels 7 and 8, the former forming the wind chest 'for the primary valve, and the latter the wind chest for the secondary valve, said Wind chests being suitably connected at their . ends bv pipes 9 and 10 with an air exhausting mechanism, not Shown, such as a bellows or the like. .A Recessed below the wind chest 7 and spaced apart according tothe distance between the keys of thepiano are air chambers 11, one of which vis Shown in Fig. 2. The chamber 11 is Separated from the wind chest 7 by a yielding diaphragm 12 provided at its `center with a 'washer 13 upon which the lower end of the primary valve stem 14 rests. Mounted upon the steel plate 4 is van vinverted cup'v 15, having an opening 16 communicating with the wind chest 7, and an opening117 leading to the outer air. Y f

Thevalve stem 14 is provided with the packed- valves 18 and 19. AS the valve stem 141s raised the valve 18 contacts with the steel plate 4 and closes the opening 16, and the same movement ofthe valve stem 14 raises the valve 19 to allow atmospheric air to flow through the opening 17 into the inverted cup 15 and through the tubular pas- Sage 20 to an air chamber 21, shown by broken lines in Fig. 2, and byits pressure to raise the `diaphragm 22. The lifting of the diaphragm 22'raises al secondary valve, not shown, which cuts olf the motor bellows V22a from the outsidev airand connects it with the wind chest 8, in the usual and well known manner. The air chamber 11 of the primary valve is connected by pipes 23 and 24 with theV perforations of the tracker bar, and whenever these perforations are uncovered by the perforations of the music sheet, air at atmospheric pressure will How through the pipes 23 and 24 to lift the diaphragm 12. As soon as the perforation in the tracker bar is closed by the music Sheet, the pressure of air in the chamber 11 begins to be reduced by a small bleed opening 25 in the pipe 24, said bleed opening, opening into a closed tubular bar 26. The tubular bar 26 is connected with an air exhaust mechanism, not shown, by means of a pipe 27, Fig. 2, by which a partial vacuum is maintained in the tubular bar 26. Upon the upper Side of the bar 26 are holes placed opposite the bleed openings 25 and closed by screws 28, which can be removed to allow access to the bleed openings in case the pas'- sage through the latter becomes impeded by dust or other foreignV substances.

The pipe 23 is bent at right angles at its lower end and inserted in the wooden block l in alinement with a passageway leading to the chamber 11, and its upper end is soldered into a cup shaped cap 29 having a flange 3Q, whichis notched on opposite sides' at 31, 3l, to receive attaching screws 32 by which the flanged caps are secured tothe bar 26. The cap 29 covers the end of the pipe 24, allowing the removal of dust from the pipes 24 and 23 by the removal of the cap 29, and the removal of a screw 28 over a bleed hole 25 allows the latter yto be cleared of dust, or to be enlarged, if required, in order to increase the bleeding action.`

The bars containing` longitudinal charnbers forming wind kchests and the arrangement of pneumatically operated valves for controlling the action of the motor bellows form no part of my presentl invention, as this portion of the within described apparatus is substantially the same as the pneumatic apparatus now in use in piano players. Neither do I claim broadly the employment of a tubular bar inclosing a vent chamber having a bleed device located between the openings of a' tracker bar and the primary valve mechanism, as such has been hitherto proposed. According to my present invention, I place the tubular bar 26 directly over the front side of the Vbars l, and I lead pipes 2,4 horizontally from a tracker bar through the tubular bar 26, from the backside, leavingthe top and front sides, which are readily accessible, for the removal' of the screws 28 and the flanged caps 29. The horizontal pipe 24. extends through the tubular bar 26 and terminates in the detachable cap 29, its

only connection with theinterior of the tubular bar being through the bleed opening 25.

The bleed device of a pneumatically actuated piano is a delicate mechanism, owing to the minuteness of the opening and the operation of the instrument depends for sensitiveness and responsiveness in maintaining the size of the bleed openings uniform. By my arrangement of the, bleed mechanism, the openings 25 are readily accessible by neans of the screws 28 which are located upon the top side of the tubular bar, and the ends of the pipes 25 are accessible by the removal of the caps 29. The pipes 23 are soldered to the caps 29 and are readily inserted in the block l, and the caps 29 are detachably attached tothe tubular bar 26 by screws 32.

I claim:

In an instrument of the character described, comprising a series of bars having valve controlled wind chests and motor bellows communicating therewith forming a pneumatic mechanism, the combination with said pneumatic mechanism of a tubular bar inclosing anexhaust chamber, and supported directly over the rear edge of said bars, pipes leading from tracker bar and passing through said tubular bar from the rear to the front side Vand provided with a bleed opening upon their upper sides, screws held in the upper side of said tubular bar opposite said openings, caps detachably attached to the front side of said tubular bar, and pipespermanently attached to said caps and leading from said caps to theprimary valves of the instrument. p

CLAUS E. PETERSON. Witnesses:

NELLIE WHALEN, PENnLorn CoMBnRBAoK.

Copies of this patent may be obtained for ive cents each, 'liyl addressing` the Commissioner of Patents, Washington, D. C.

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