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Publication numberUS547071 A
Publication typeGrant
Publication dateOct 1, 1895
Publication numberUS 547071 A, US 547071A, US-A-547071, US547071 A, US547071A
InventorsOfpjq frederick W. Hedgeland
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 547071 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)


No. 547,071. Patented Oct. 1,1895.


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SPECIFICATION forming part of Letters Patent No. 547,071, dated October 1, 1895. Application filed February 23, 1894. Serial No. 501,149. (No modeld To aZZ whom it may concern:

Be it known that I, FREDERICK W. HEDGE- LAND, a citizen of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Self-Playing Mechanism for Pianos or Organs, of which the following is a specification.

This invention relates to self-playing keyboard instruments,and especiallyto the means employed for rendering them automatic in their playing.

It has been my endeavor in the invention to improve the self-playing mechanism and render it more practical than previous constructions; also, to adapt it to use in upright pianos of ordinary form without anyincrease in the size or change in the shape of the instrumentcase; also, to avoid adding to the instrument-case any visible mechanism or feature which will impair the appearance of or disfigure the case.

In my improved instrument I operate the keys by means of a series of small bellows, commonly called pneumatics, one for each key, and control such pneumatics by electrical devices set in operation by the moving perforated paper strip customarily employed in this class of instruments. The action is therefore partly pneumatic and partly electrical. The electric circuits are normally open, but are each provided with a circuitcloser consisting of a stationary contact and a spring-contact, the latter located so as to bear upon the moving perforated strip and so the perforations in the strip will allow the closing of the circuit. A suitable motor is employed to maintain the wind-pressure necessary to operate the pneumatics, and the drum whereon the perforated strip is wound and by which it is moved may be actuated by the same motor. I prefer that this motor should be an electric one, and to control its operatingcircuit by means of a spring-circuit breaker which is allowed to operate by means of a perforation in the perforated strip.

In order to adapt the invention to use upon existing styles of instruments, I have placed the moving strip immediately under the keyboard,with the winding and unwinding drums below the ends of the board, so that no interference is thereby caused with the limbs of any person or persons seated at the instrument. The motor, the wind-boxes, the pneumatics, the magnets through which the valves of the pneumatics are actuated, and the bellows are all located within the base portion of the case and behind the knee-board, while the batteries for applying the electric energy are also located within the case and in ordinary upright pianos between the back posts of the case. It will thus be seen that no change in the construction of ordinary upright pianos is necessary in order to permit the application of my invention thereto and that it may be easily applied to existing instruments of that style. The only parts added to the outside of the case of such pianos are the paper drums, and they are so placed as to be inconspicuous, so that it is also true that the general appearance of the instrument remains unaffected.

Many features of the invention may also be used in other pianos and in cabinet and other organs.

The details of my invention are fully shown in the accompanying drawings, wherein' Figure 1 is a front view of an upright piano to which my invention has been applied, the knee-board being left 01f, so as to disclose the inner construction. Fig. 2 is a partial vertical section enlarged, showing the motor, windpressure-creating mechanism, and the pneumatics. Fig. 3 is a cross-section showing the same parts as Fig. 2. Fig. 4 is a detail section of the pneumatics and their controlling devices. Fig. 5 is a front elevation of the perforated strip and its supporting-drums. Fig. 6 is a perspective of the series of circuit-closers employed to close the action circuits. Figs. 7 and 8 are detail sections of the perforated strip, the for'mer showing one of the circuit-closers and the latter showing the breaker employed in the motor-circuit, both in action. Figs. 9 and 10 are diagrams of the motor-circuit and the electric action-circuit, respectively. Fig. 11 is a perspective of the back of the piano-case. Figs. 12 and 13 are details of the paper-winding drum.

In the drawings, A may represent the case of the instrument, the one shown being that of an upright piano. B is the keyboard, and b b are the keys of theinstrument. The major portion of my improved automatic mechanism is located in the lower portion of the case behind the front or knee board thereof and in front of the strings and frame, and a portion of it is placed under the keyboard.

I will first describe the pneumatic action for operating the keys. 0 is a motor, preferably an electric one, the duty of which is to operate the airfeeders D, which are similar in construction to the feeders commonly employed with organ-bellows, and whereby the necessary wind-pressure is created. These parts are mechanically connected by pulley 0 upon the motor-shaft, belt a, pulley O,

shaft C sprocket-pulley C chain 0 wheel C crank-shaft C carrying said wheel, pitman C and arms d, attached to the movable sides of the feeders. I employ a plurality of feeders in order the better to obtain a steady pressure and to even up or distribute the work put upon the motor. The feeders force the air into a vertical passage-way D, Which supplies it to a pipe D conducting it to the res ervoir D the top whereof is adapted to rise as the internal pressure increases and is pressed downwardly by the spring D. To prevent excessive pressure-a valve D located in the passage D, is made to open whenever such pressure occurs by power received from the movable top of the reservoir and to give the air in said passage vent back into the feeders through separate passages D and the series of pipes D connecting said passages with the different feeders. The valve D is connected to the reservoir-top by arm 61 attached to the valve, connecting-rod d ,elbowlever (1 and belt (1 passing under pulley d and united to arm d upon the reservoir-top. lrVhen the reliefvalve is open, the air simply circulates through the passageD and the feeders instead of being forced into the reservoir and also acts to keep the feeder-inlets closed against the entrance of fresh air. From the reservoir the air passes by the pipe E and air-trunk E into the wind-boxes E of which there is one for each row of the pneumatics F. The latter are similar to the pneumatics employed in organ actions and are preferably arranged in three rows, as that arrangement gives room for the large number necessary, it being requisite to provide one for each key of the keyboard. They are disposed horizontally upon the wind-boxes, and the passages f, leading from the boxes into the pneumatics, are guarded by double-headed sliding valves F, which are operated as hereinafter fully set forth. One head of these valves controls the inlets f of passagesfand the other controls the air-outlets f from said passages, the inlets being normally closed and the outlets normally open and each being open when the other is closed. The movable side of each pneumatic is joined to a lifting rod or bar F in some suitable wayas, for instance, by an outstanding arm F secured to the movable sideand said lifting-rod is placed immediately under the rear end of the key it is intended to operate. It will thus be seen that whenever the motor is set in operation the feeders will act to charge the wind-boxes with air under pressure, and that whenever the valves F are operated and the inletsf opened the pneumatics will be charged, so that the keys with which the latter are connected will be sounded. Each valve F is electrically operated by a magnet G, located in proximity to the valve, and a pivoted lever G, carrying the armature of the magnet and actuated thereby and so located as to insure its contact when the armature and lever are drawn to the magnet, with the button f upon the stem of the valve. In this manner the valve is slided so as to open the inlet f and charge the pneumatic, and it is instantly brought back to its normal position whenever the electric force is withdrawn by the air-pressure acting against its heads. The several magnets G are located in and energized by suitable electric circuits, which I prefer should consist of individual wires H, one for each magnet, and all adapted to be connected to the single wire H, leading to one pole of the battery H and individual wires H one for each magnet, all joined to the single wire 11 leading to the other pole of the battery. The switch H in wire H enables all the circuits to be opened and closed, and circuit-closers are also employed with each of the individual circuits, as presently to be described.

The moving perforated paper strip is shown at J and is located immediately below the keyboard, where it takes up no valuable room and may be easily concealed. The unwinding roll or drum is shown at J and the Wind ing or drawing drum or roll is seen at J these drums being located under the ends of the keyboard and being covered in front by hangers or doors J A depending strip J may be employed to prevent the moving strip from being visible at any point, and this strip is cut away at the center to avoid interference with the knees of players using the piano for manual playing. The perforated strip may be such as is now in common use. Immediately above the moving strip are a series of springs K, all mounted upon a bar K and each joined to one of the wires IF, the bar standing transverse of the strip. The springs correspond in number with the number of keys and circuits, and each carries a stud K adapted to bear upon the strip J and enter such of the perforations i therein as present themselves in line with the stud. \Vhen the stud enters one of the perforations, it brings about contact between the free end of its spring K and a contact-plate K which is electrically joined to the wire 11, so that, supposing the controlling-switch to be closed, a circuit is completed and a current generated, which passes through and energizes the magnet of the circuit, and the magnet is thus caused to operate its lever and corresponding valve F, all resulting in the sounding of the key or note to which the circuit and valve belong. The stud when it falls into the perforations is met by an insulating-strip in the transverse bar K and is lifted out of the perforation by the continued movement of the strip, thus breaking the circuit at the plate K The stud now rides upon the surface of the strip and keeps the circuit open until another perforation allows it to descend and renew the contact between the spring and contact-plate. The breaking of the circuit of course allows the valve F to move back into its normal position, shutting off the air-pressure from the pneumatic and allowing the air in the same to escape. The stud enters the strip only a slight distance and is moved only slightly either up or down, and consequently there is little danger of tearing the paper or of objectionable wear upon the walls of the perforations, and there is also a saving of time both in opening and closing the valve F. The bar K maintains the moving strip at the proper horizontal plane to insure lifting of the spring-circuit closers and thus avoid any permanent closing of the action-circuits.

Motion is given the winding-drum by the pinion L upon the end of crank-shaft- C meshingwith the gear L upon the journal L of the drum. This gear L is free to rotate independently of the drum; but it carries a catch or pin L adapted to enter any of the openings L in the overhanging flange of the drum-head L and thus carry the drum with it. A spring L acts to keep the catch in engagement with the drum. The catch is also provided with a right-angled projection L whereby it may be moved out of engagement, said projection traveling in the slot L in the arm of the gear, and the side enlargement L of the slot permitting the catch to be detained from engagement against its spring L The ability to detach the gear from the drum afforded by this construction permits the perforated strip to be drawn back and wound upon drum J.

The electric circuit for operating the motor is composed of the wires M, connecting one pole of the battery or source of energy with the motor, and the wire M, connecting the other pole therewith. In one of these connections 1 place a switch m, whereby the current may be directed through one or more resistance-coils m and the speed of the motor be thereby controlled to accord with the time required by the music being played. In the other wire I locate a circuit-breaker adapted to be operated by the perforated strip, and which may consist of an electrically-connected spring 0, located and constructed so it will ride upon the surface of the strip and be held up thereby, with its free end bearing against the contact-point 0, and thus to maintain the circuit while the instrument is playing, but adapted to fall and destroy its contact with point when the slit or opening 0 in the perforated strip presents itself at the conclusion of the playing. A supporting cross-bar 0 is placed under the perforated strip and beneath the circuit-breaker to insure the maintenance of the circuit-contact with point 0 during operation. By means of this circuitbreaker the motor is automatically stopped at the conclusion of the piece being played. The switch m is preferably located where it is readily accessible-as, for instance, upon one of the key-blocks, as shown.

The controlling-switch ofthe action-circuits is connected to the top of the bellows-reservoir by a cord or other suitable device, so that when the reservoir becomes empty and the top descends the switch will be opened and the circuits destroyed, and a spring P also acts upon the switch in a direction contrary to the cord and closes the same whenever the reservoir is filled sufficiently to create slack in the cord. Through these devices the circuits are automatically opened whenever the windpressure gives out and automatically closed whenever it becomes strong enough to operate.

I prefer to use several batteries H whereby to obtain the electric energy necessary to operate the various circuits employed in the instrument and to locate such batteries, in the case of upright pianos, in the spaces between the vertical posts N of the back frame. I thus obviate the necessity, which would otherwise exist if they are to be borne in or upon the instrument so as to be movable therewith, of placing them inside the case, where all the room is needed for other things, or enlarging the case to accommodate them.

I do not claim herein anything shown in patent to Pain, No. 417,680.

I claim- 1. The combination in a self' playing key board instrument and with the keys thereof, of a pneumatic action for operating said keys a bellows for said action, electrical devices and circuits for controlling the pneumatic action, a rnotor, an electric circuit controlling the motor, the moving perforated music strip, circuit closers in said action circuits operated by said strip, and a circuit breaker in said motor circuit operated by said strip, substantially as set forth.

2. In an electric pneumatic action for musical instruments, the combination with the .bellows and the electric circuits of a switch controlling said circuits, and connections between said switch and the bellows whereby the switch is opened when the air pressure in the apparatus ceases, substantially as specified.

3. The combination of the pneumatics, the valves controlling the pneumatics and the electric circuits and magnets operating said valves, with the bellows and the switch common to all said circuits and which is operated to open or close the same according to the presence or absence of the air pressure in the apparatus, substantially as set forth.

at. The combination with the pneumatics, the valves controlling the pneumatics, the electric circuits and magnets operating said valves, of the bellows for charging the pneu matics and means operated by the bellows for ITO automatically breaking said circuits When the With the feeders and the pneumatics for actair pressure ceases, substantially as set forth.

uating the keys, substantially as set forth. 5. The combination in a self playing instrument, With the motor, the feeders operated by FREDERICK HEDGELAND' 5 the motor, and the reservoir, of the relief valve Witnesses:

mechanically connected to the movable top of H. M. MUNDAY,

the reservoir, air pipes connecting said valve EMMA HACK.

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Cooperative ClassificationG10H1/383