US3033068A - Pneumatic for piano player - Google Patents

Description

May 8, 1962 Filed Jan. 51, 1961 'lz l J. A. WESTFIELD PNEUMATIC FOR PIANO PLAYER 2 Sheets-Sheet 1 Sle INV EN TOR.

JOHN H. WESTF/EM y 1962 J. A. WESTFIELD 3,033,068

PNEUMATIC FOR PIANO PLAYER Filed Jan. 31, 1961 2 Sheets-Sheet 2 mfimm United States This invention relates to improvements in devices which are known in the industry to which they pertain as piano players and player pianos. More particularly this invention relates to improvements in the bellows employed in piano players and commonly known in trade as pneumatics.

In the present instance, the pneumatics embodying this invention are to be used in a piano player such as that disclosed and described in United States Patent No. 2,953,957 that was issued on September 27, 1960. However, this is not restricted to use in the device of that patent.

It is the principal object of the invention to provide a pneumatic that is more positive and stronger in its action; that it is less expensive in its construction; that it is substantially lighter in weight and has longer life than those now generally in use.

It is also an object of this invention to provide the present pneumatic with an improved type of valve mechanism that is less expensive; that has easier and quicker action and which is of lesser weight than is ordinarily required. Furthermore, a pneumatic in which the air passages are given greater area and more air capacity, thus to insure more uniformity in their operation.

Further objects and advantages of the invention reside in the specific details of construction of parts; in the combination of parts and i nthe mode of use and operation of the improved pneumatic, as will hereinafter be fully described.

In accomplishing the above mentioned and other objects of the invention, I have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a portion of a piano player showing a plurality of pneumatics embodied by the present invention as mounted therein for use.

FIG. 2 is a somewhat enlarged side view of one of the pneumatics, showing its mounting on and its air connection with the vacuum chamber of the player with which it is used.

FIG. 2a is a longitudinal section of a pneumatic, shown at a reduced scale and indicating the separate formation of the valve housing and top wall section of the bellows or pneumatic preparatory to their assembly.

FIG. 3 is a longitudinal section of the pneumatic, showing the valve housing and valve as applied thereto, and the location of the valve actuating diaphragm.

FIG. 4 is a cross-sectional view taken on line 4-4 in FIG. 3.

FIG. 5 is an enlarged sectional detail showing the valve housing with valve lifted therefrom for explanatory purposes.

FIG. 6 is an enlarged top view of the valve housing with valve as disposed therein and particularly showing the triangular shape of the valve flange.

Referring more in detail to the drawings:

It is to be understood that the details of construction of the piano player and piano are not necessarily confined to those herein illustrated; the novelty of the present invention residing more particularly in the details of the pneumatics as designated individually in their entireties in FIGS. 1 and 3 by reference numeral 10.

In FIG. 1, a fragmental sectional detail of a piano player has been illustrated. This view shows, in its lower atent part, the forward end portion of one of the black keys 14 of the piano and the forward end portion of an adja cent white key 15.

These two keys are mounted in the piano in the usual manner and when struck downwardly for playing, each will actuate certain devices, not herein shown, to cause the production of a musical tone of the chromatic scale. When a piano key whether white or black, is disengaged by its corresponding key striking lever, embodied in the piano player, as presently explained, it immediately returns to its normal horizontal position, as for example, to a position corresponding to that of the keys 14 and 15 as shown in FIG. 1.

The mechanisms of the present piano player are contained compactly in a housing, designated in its entirety in cross-section in FIG. 1 by reference numeral '16. As seen in this cross-sectional view, the housing comprises a vertical front wall 16 and a horizontal top wall 16x. At its back side the housing is closed by an air tight vacuum housing or chamber 17. Preferably the housing 16 and vacuum chamber are fabricated from aluminum plates and in use, the housing is mounted on the keyboard portion of the piano, for example, as has been illustrated in FIG. 1 or in any other suitable manner.

The present piano player is designed to use the usual form of perforated record strip 26 which is herein shown as being advanced between strip winding rolls 18 and 19, across the usual tracker bar 25; these parts being mounted upon the housing 16 as shown in FIG. 1. The strip winding rolls 18 and 19 are of the usual type used for this purpose and are mounted in horizontal, parallel relationship with and along the front and back sides of the tracker bar 25,

The record strip 26 is advanced for playing by the usual means from the rear roll '19 to the forward roll 18 and as advanced, is drawn flatly against and across the transversely curved top surface 25' of tracker bar 25. This is formed substantially to its full length with a succession of air passages 45, each opening at its ends to the top and bottom surfaces of the tracker bar. These air passages, in their successive arrangement along the tracker bar, correspond to the individual piano keys as arranged successively along the keyboard, and each passage is connected at its lower end by an air tube 46 of small diameter leading through the vacuum chamber 17 and having a metal tube connection 47 to one of the pneurnatics or bellows 10, as shown in FIG. 1; each pneumatic preferably having a fixed mounting in the housing 16 above the key corresponding thereto as shown.

It is to be observed best in FIG. 3 that each pneumatic 10 comprises -a stationary top housing structure 50 and a bottom wall member 51 coextensive with the top structure and hinged at its inner end as at 52 to the rear edge of the bottom wall of the top structure. This member 51 is adapted to be actuated at its outer or forward end toward and from the top structure 50' as presently explained.

At its forward or swinging end, each bottom wall member 51 is equipped with an extending ear 51e through which one end portion of a vertical wire rod 53 is extended and in which ear it is operatively connected. At their other ends these wire rods 53 are operatively connected to the forward ends of horizontally disposed levers 56 which have inner end portions extended rearwardly to closely overlie the top surfaces of the finger striking portions of the piano keys corresponding thereto, as shown in FIG. 1.

Each of the levers 56, as thus arranged in succession along the keyboard for the actuation of the piano keys, is pivotally supported between its ends by a pivot pin 59 that extends between paired, laterally spaced, downwardly ao-saoee directed ears 58' of a bracket 58 that is rigidly fixed to and extended forwardly from a stationary means of support which, in this particular instance, as best shown in FIG. 1, is the bottom wall of the vacuum chamber 17 It is further to be noted by reference to FIGS. 1 and 2 that the top housings 56 of the pneumaticsor bellows 10 are rigidly and operatively fixed at their bases or larger inner ends, to the front wall of the vacuum chamber 17 to extend horizontally and forwardly therefrom and that their lever operating connections are made with the ears Slle of the bottom wall members 51 and with the forward end portions of the corresponding key striking levers 56.

It is further to be explained that each of the pneumatics 10 is enclosed and sealed on sides, top, bottom and forward end by a suitable flexible wall material that gives the hingedly joined parts St) and 51 the desired bellows action. Preferably the enclosing material is a rubberized, air tight fabric that is adhesively applied to the surfaces of the parts '50 and 51. This material as applied across the joined opposite side surfaces of the bellows serves additionally to hingedly join the parts 50 and 51 for their bellows like action. This flexible covering material is designated in FIGS. 3, 4, and 6, by reference numeral 62.

It is also to be mentioned here that the parts comprising the top structure 56 of the pneumatic and its bottom wall member 51 are molded of plastic, or a like material, to insure strength, durability and air tightness. Furthermore, it is used because such material is not afiected by moisture. Also for manufacturing expediency, it is preferred that the top structure 50 be made in two separate pieces, as has been illustrated in FIG. 2a; one of which forms the valve housing 63 and the other provides an air chamber 64 of substantial capacity that, when the parts 56 and 51 of the pneumatic are assembled, opens as shown in FIG. 3 into the top of the bellows chamber 65 as defined between the parts 50 and 51.

Referring again to FIG. 3 it is to be observed that the valve housing which is designated separately in FIG. 2a byreference numeral 63, is fitted to and sealed in a stepped down recess 63x formed in the top side of the larger end portion of the part 50 as seen in FIG. 2a. The valve housing 63 is formed in its lower portion with a downwardly opening air chamber 66 that overlies an upwardly opening chamber '67 in the lower portion of the down stepped end portion of part 56, between which chambers 66 and 67 a flexible air tight diaphragm 68 is sealed, as has been shown in FIGS. 3 and 4.

The valve housing 63 is formed with an upwardly opening valve chamber 68 which is provided centrally at its lower end with an opening 70 of reduced diameter opening at its lower end into the chamber 66 that is immediately above the diaphragm 68. At its top end the valve chamber 69, which is shown to be of increased diameter, opens to the atmosphere.

Immediately about the upper end of opening or passage 76, the valve chamber is formed with an annular seat 71 against which the control valve member '72 may close. This valve 72 is free floating and, as best shown in FIGS. 3 and 5, has a downwardly extending stem 73 projecting from its underside and. passing with clearance downwardly through the opening 70 and engaging the diaphragm 68, as shown in FIG. 4.

Press fitted within the top end of the air passage 69 is a valve retainer 74 of annular form which permits but serves to limit the lifting action of the valve '72.

The chamber 66 which in FIG. 3 is shown to be located immediately above the diaphragm 68 has an opening '75 in direct and open communication with the vacuum chamber 17, and the chamber 67 has open connection with the tube 47 leading to the air tube 46 that connects with the corresponding channel 45 of the tracker bar 25.

In the operation of the player piano, the valve member 72 may, under influence of air pressures in the chambers 66 and 67, move downwardly to close over the opening 76 or upwardly to close against the central opening 74' in the annular retainer 74 according to pressure differentials affecting it.

It has been shown best in FIGS. 3, 4 and 5 that the valve 72 is formed with a circular body portion 72b about which a projecting flange 72 of substantially triangular outline is formed; its outline being best shown in FIG. 6. The rounded corner portions of the triangular flange terminate quite close to the walls of the passage 69 thus to retain the valve centered without binding. It is apparent also by reference to FIG. 6' that the defining straight edge portions of the projecting flange, provide between the comer portions relatively wide air passages as at p in FIG. 6, through which air streams will be drawn when the valve is lifted or unseated. These air streams are of equal volume and operate to retain the valve centered in the passage. Thus, the usual guides of metal for holding the valve in position and against binding are not required and the expense of their making and application is avoided.

it is also to be observed in FIG. 3 that the metal tubes 47 which provide connections between the air tubes 46 and chambers 67 have small air ports 84 formed therein and opening into the vacuum chamber.

Now, assuming that the pneumatics are provided as has been shown in cross-section in FIG. 3, their operation is as follows:

As the record strip 26 is drawn across the tracker bar 25 to cover and closed the top end of the bar passage 4-5 for any bellows, the condition of vacuum in the valve chamber 67 of the corresponding pneumatic and atmospheric pressure outside coact to cause the valve 72 to be drawn down and close against seat 71. Thus the atmospheric air connections to the pneumatic 10 through its top opening 76' and a passage 80 leading from chamber 69 to the large downwardly opening chamber 81 in part 56 will admit atmospheric air to the bellows and open it as in FIG. 3. As the record strip advances and one of its perforations opens the atmospheric passage 45, atmospheric air is admitted to chamber 67 and this lifts the valve 72 and closes the atmospheric opening 74, thus opening a direct vacuum connection from vacuum chamber 17, through port 75, chamber 67, passages 70 and 80 to the bellows causing its instant collapse to'effect the striking of the corresponding piano key through the pull of rod 53 and lever 56-. i

What I claim to be new is:

l. The combination with a source of vacuum and a controlled source of air under atmospheric pressure, of a pneumatic of the character described comprising a top housing structure formed along opposite end portions respectively, with a downwardly opening air chamberand an upwardly opening air chamber; said top housing structure incorporating a valve housing therein, overlying the upwardly opening air chamber of said top structure and formed therein with a downwardly opening air chamber registered with said upwardly opening air chamber, a flexible diaphragm separating said registering upwardly and downwardly opening air chambers, a bellows associated with said top housing structure in open communications with its downwardly opening air chamber, a valve chamber in said valve housing having an air port opening from its lower end into the downwardly opening chamber of said valve housing and having its upper end equipped with a ported valve retainer through which said valve chamber may be opened to atmospheric pressure; said valve housing also having an opening therein providing direct communication between said valve chamber and the downwardly opening air chamber first mentioned and having another opening therein providing direct communication between said source of vacuum and its downwardly opening air chamber of said valve housing, a tube providing an air connection between the controlled atmosphere air supply and said upwardly opening chamber of the top housing structure, and a poppet valve contained in said valve chamber having a stem engaged with and operable by the upward flexing action of said diaphragm under differential in pressures acting against opposite sides thereof to lift the valve to thereby close the atmospheric opening of the valve retained and subject the bellows to closing action under influence of vacuum or under downward flexing action of the diaphragm to subject the bellows to inflating pressure of atmospheric air entering through the ported valve retainer.

2. The pneumatic of claim 1 wherein said valve chamber of the valve housing is of cylinderical form and wherein said poppet valve as actuated by said flexible diaphragm is openable upwardly to a position closed against the atmospheric opening of the valve retainer or downwardly to close over the air port at the bottom of the valve chamber.

3. The pneumatic of claim 2 wherein the poppet valve has a head portion formed with a peripheral flange providing points of guiding contact, at evenly spaced intervals thereabout with the chamber walls and providing air flow passages of like area between the points of guiding contact.

4. The pneumatic of claim 3 wherein the said bellows comprises a bottom wall member that is hinged at one end to said top housing structure, and wherein said top structure and the valve housing as incorporated therein are enclosed in a flexible wrapping that enables the bellows chamber to retain the valve centered in the passage, whereby the usual guides of metal for holding the valve in position and against binding are not required and the expense of their making and application is avoided.

References Cited in the file of this patent

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