US664004A - Electrical piano. - Google Patents

Description

Patented Dec. I8, I900.

REYNOLDS.

ELECTRICAL PIANO (Amalia-don 81nd June 10, 1809. lanurad Kay 17, 1900.)

(No Model.)

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STEPHEN K. REYNOLDS, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO FRANK W. CHAMBERLIN, 0F SAME PLACE.

ELECTRICAL PlANO.

SPECIFICATION forming part of Letters Patent N 0. 664,004, dated December 18, 1900.

Application fileddune 10, 1899. Renewed May 17, 1900. Serial No. 16,989. (No model.)

To all whmn it may concern.-

Be it known that I, STEPHEN K. REYNOLDS, a citizen of the United States, residing at. the city of New York, borough of Manhattan, State of New York, have invented certain new and useful Improvements in Electrical Pianos, of which the following is a full, clear, and exact description. I

This invention relates to electrically-operated musical instruments, and has special reference to pianos. The principle of locating ordinary electromagnets adjacent to the keylevers of the piano,.attaching an armature to the key-lever, and depressing the key by the attraction of the magnet when it is energized has been em bodied in various mechanisms for automatically playing a piano. Such devices have, however, proven to be only moderately satisfactory in View of the fact that itis quite impossible to control the expression of the music. A certain amount of current must be put through such an electromagnet to make its armature respond at all, and when sufficient current is used to obtain a response a sharp movement of the key is invariably the result,producinga staccato effect, and this effect cannot be softened or modified by varying the current. Instead of using an ordinary electromagnet and its armature I purpose using a solenoid and its axial core, by which means I am able to produce a stroke of the key dependent almost entirely upon the amount of current permitted to flow through the coil of the solenoid. The nature of the attractive force of a solenoid is in one respect the opposite of that existing in ordinary electromagnets. In a magnet the stroke of the armature increases in strength and speed as it approaches the pole of the magnet and is weakest at the beginning of the stroke, whereas in a solenoid the strongest pull is at the beginning of the stroke and its rapidity and strength decrease as the magnetic center of the movable core or armature approaches the center of the coil. Forthis reason very light currents which would not affect an ordinary magnet will cause a response in a solenoid, and the nature of the blow or pull delivered by the solenoid-core can be varied through a wider range by varying the battery-power than is the case with the ordinary magnets. Hence by using solenoids to move the keys of a piano I am able to obtain modulations of tone and touch which cannot be obtained in the old Way, and this constitutes the main feature of my invention.

For a somewhat-detailed description of my invention reference will be made to the accompanying drawings, in which- Figure 1 is a perspective view of one end of the keyboard of a piano with my invention attached thereto. Fig. 2 is an enlarged sectional View through the frame supporting the solenoids and through the keyboard. Fig. 3 is an end view of the rolls upon which the perforated music-strip is wound and unwound and the circuit-closing devices cooperating therewith, and Fig. a is a diagram of the circuits.

One object of my invention being a device which may be readily attached to and detached from an ordinary piano, the solenoids, which are the only parts that need be attached directly to the piano, are mounted in a casing or frame A, whose bottom board a is somewhat longer than the keyboard and rests upon the usual spacing-blocks b at each end of the row of keys. To hold the frame steadily in place, the blocks 1) may be provided with buttons 1), adapted to pass through slots at in the projecting ends of the bottom board of the case and then given a quarter-turn. Upon or in the bottom board of the case are mounted two rows or series of solenoids 0, one for the White keys and one for the black, one solenoid being placed centrally above each key and with its axis at right angles to the key. The cores 0 of the solenoids are provided with non-magnetic extensions 0, having heads 0 preferably of soft rubber, which rest directly upon the keys, the normal tendency of the key to rise after being depressed being relied upon to hold the core in its elevated position. For the purpose of deriving full benefit of the current used the coil is iron-cladthat is to say, a cylinder of iron d surrounds it and iron heads cl are used to complete the magnetic circuit. The cross-heads c on the upper ends of the cores prevent the latter from falling out of the case when it is removed from the keyboard.

For the purpose of sending currents of electricity through the solenoids properly for playing a piece of music I purpose using any suitable means; but I have illustrated the well-known perforated sheet of paper, which is caused to travel in front of circuit closing fingers connected with the respective solenoids. The rolls for this perforated sheet will preferably be located in a casing E, attached to the top of the casing A at about its middle. The construction of the rolls and circuitclosers is shown in Fig. 3,wherein e is the roll from which the perforated strip e is drawn and simultaneously rewound upon a second roll 6 the latter being driven by any suitable motor. On the way from one roll to the other the perforated strip passes over a metallic rollerf, opposite which is placed a bar g, carryinga series of spring contact-fingers g, connected, respectively, with the solenoids. The perforations in the strip are made in lines corresponding to the position of the fingers, so that as the strip moves along the circuit will be closed whenever a perforation is presented to a finger by the finger dropping through the perforation onto the metallic roller. The battery S may be located eitherin the same box E with the motor and rolls or at any other suitable place. For the purpose of throwing into use more or less of the battery as the expression-marks of the music dictate I provide a switch I, the lever of which may be moved by the operator. This switch will be preferably located on some part of the casing A or E. With the speed of the motor, the batterypower, and the usual loud and soft pedals of the piano under the control of the operator the expression given to the music may be controlled to a nicety.

To obtain the lightest strokes upon the keys, the switch will be thrown to put the smallest amountofbatteryinto circuit. The armatures of the solenoids will respond to this and force thekeys slightlydownward. For radnallyincreasing the sound the switch is moved to gradually throw more battery into the circuit, and the solenoids correspondingly respond. In all cases the stroke of the solenoid-core is of such character that either a staccato or a sustained tone may be produced at the will of the operator.

An incidental advantage in the use of solenoids is the fact that no attachment to the keys is necessary, and the solenoids may be placed at any point where their cores may rest upon the keys. It thus becomes possible to mount the entire device directly upon the keyboard, and this may be done in many instances without any change in the piano itself.

Having described my invention, I claim The combination with a piano of a series of solenoids supported above the keyboard there of and with their axes at right angles thereto, the cores of said solenoids being provided with striking-l1eads resting freely upon the keys, the cores of the solenoids being held in their withdrawn position by the same force which holds the keys in their normal position.

In witness whereof I subscribe my signature in presence of two witnesses.

STEPHEN K. REYNOLDS.

lVitnesses:

FRANK S. OBER, G. S. KENNEDY.

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