US681261A - Automatic piano. - Google Patents

Description

No. 68|,26l. Patented Aug. 27.'|90l. T. B. POWERS.

AUTOMATIC PIANO.

(Application filed Apr. 18, 1899.) (No Model.) 3 Sheets-Sheet I.

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542; ATTORNEY No. 68l,26|. Patented Aug. 27, I901. T. B. POWERS.

' AUTOIATIC PIANO.

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UNITED STATES PATENT OFFICE.

TIMOTHY B. POWERS, OF NEW YORK, N. Y., ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE MAGNETIC PIANO COMPANY, OF NEIV JERSEY.

AUTOMATIC PIANO.

SPECIFICATION forming part of Letters Patent No. 681,261, dated August 27, 1901.

Application filed April 13, 1899. Serial No. 712,866. (No model.)

To all whom it may concern:

Be it known that I, TIMOTHY B. PowEEs, a citizen of the United States of America, and a resident of New York city, county and State of New York, haveinvented a new and useful Improvement in Automatic Pianos, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

My invention relates particularly to an improved form of mechanism for depressing the keys or some other portion of a piano-action to give the desired tone through the closing of the circuit of a simple electromagnet, thus doing away with the usual complicated form of intermediate mechanism commonly in use. Heretofore a direct action through the medium of a simple electromagnet has been impracticable, owing to the peculiar action of an electromagnet on an armature, by which the strength of the pull was so rapidly reduced as the armature receded from the magnet. In my invention I have arranged a new and peculiar movement of the armature relatively to the magnet, whereby the strength of the pull is,to a certain extent,equalized. The result of this is an extremely efficient and simple form of mechanism for operating a piano automatically and one which uses a minimum amount of current or power in its operation.

I will now proceed to describe mechanism embodying my invention, and will then point out the novel features and claims.

With reference to the drawings, Figure 1 is a vertical section through a piano, showing a conventional form of piano-action and having an automatic attachment embodying my invention in connection therewith. Fig. 2 is a detailed view of a portion of the piano looking from the front, showing a drawer for containing the music-roll and some of the operating-magnets for the piano-action. Fig. 3 is a detailed view of a cross-section of the drawer containing the music-roll and the contactfingers. Fig. 4 is a top view of the same.

Fig. 5 is a detailed view, on an enlarged scale, of my improved form of magnet and armature.

Similar reference characters describe corresponding parts in all the figures.

made so far with success of a platinum strip running the entire length and connecting with one pole of the battery or dynamo.

16 designates a plurality of contact-fingers mounted upon an insulated bar 17. There is one contact-finger for each note to be played, which contact-finger connects with its individual magnet, to be hereinafter described, and from thence through a common return to the opposite pole of the battery or dynamo, to which the contact-strip 15 is connected.

The feed or take-up roll 14 may be driven from any suitable source. I have shown a pulley 18 on its shaft and a cord passing over the same, which is adapted to connect with an electric or other motor, (not shown,) this forming no part of my present invention.

By the above arrangement it will be seen that as the feed or take-up roller revolves and draws the music-roll or perforated strip across the contact-strip 15 the contact-fingers 16 will engage with the contact-strip 15 and close their respective circuits in accordance with the arrangement of the perforations. If now, therefore, the magnets are arranged through their armatures and suitable connecting mechanism to operate thekeys or other portion of the piano-action, the piano will be caused to play automatically under the control of the music-roll.

I will now describe one of the magnets, its armature, and its connection with the pianoaction, it being understood that such description will answer equally well for any or all of the other magnets herein shown, they being all of similar construction.

19 designates a pair of coils of the ordinary horseshoe-magnet form, having a soft-iron core adapted to be magnetized upon a circuit being closed through the said coils and a bat tery or dynamo.

2O designates an armature pivotally connected to links 21, which in turn are pivoted to a stationary portion 22. The links give to the armature a parallel motion toward and away from the magnet in a curved path. The armature is shown in Fig. 5 in its extreme position away from the magnet. When the circuit is closed through the magnet by reason of its particular contact-finger coming in contact with the contact-strip 15, and thereby completing the circuit, the armature is drawn toward the magnet through a curved path, the curve being described by the links 21. The length of the links is so regulated that the armature shall never quite touch the core of the magnet. The efiect of this movement is such that at the time the armature is 'farthest away from the magnet, and hence the electric effect of the magnet is weakest on the armature, the position of the links will give the greatest mechanical purchase. As the armature approaches the magnet the mechanical purchase decreases as the electrical effect increases. This forms an electrical me chanical compensating device which is extremely eflicacious in the performance of the function herein desired. Afurther extremely desirable result, and one which is very valuable in a mechanism of this description, is the holding of the armature out of contact with the magnet-cores at all times without applying a direct or rigid mechanical stop. The eifect is to permit a Very desirable flexibility of action and to prevent objectionable sticking, as is common when the armature is stopped by contact with the cores themselves, owing to the closing thereby of a magnetic circuit, the induced magnetism therein remaining after the electric circuit is broken. In the form of connection here shown between the armature and the piano-action the lower links 21 are provided with outwardly-extending portions 23, to which is pivotally secured a connecting-rod 24. This pivotal point is so located that the direction of a straight line drawn therethrough and through the pivotal connection of the link upon its support approaches more nearly the direction of the line of pull of the connecting-rod than does the direction of a straight line drawn through the said pivotal connection of the link upon its support and the pivotal connection of the link with the armature. As shown in the drawings, this is effected by curving the extensions 23. This results in a very slight movement of the piano-action during the first portion of the movement of the armature and assists in overcoming the inertia of the parts and increasing the delicacy of the movement. The

upper end of the connecting-rod has secured thereto a button which works freely in a recess 26, formed in the under side of the key, The said recess has a contracted mouth, through which the connecting} rod passes.

The said contracted mouth is conveniently formed in a plate 27, which is secured to the under side of the key over the said recess and against which the button 25 is adapted to bear. When a magnet is energized and its armature attracted, the connecting-rod will be lowered and the key connected therewith will be depressed, causing a note to be sounded in a manner corresponding to that employed in playing the instrument by hand. Should it be desired to play the instrument by hand, the key may be depressed as is usual and the button 25 of the connectingrod 24 will be received farther within the recess and the automatic attachment will hence not be operated or interfered with.

The armature is arranged to return to its her, in order to take up shock and deaden the sound. The key will return to its normal position by means of the ordinary action common thereto. I may of course employ a spring to return the armature to its non-operative position, if desired.

I have shown and described the magnet, its armature, and connecting-rod as being applied directly to the keys controlling the piano-action. I may, however, if I so desire, connect the said mechanism with any other portion of the piano-action.

What I claim is-* 1. In an automatic attachment for pianos, the combination with a piano-action of an electromagnet, means for closing circuit electrically to energize the electromagnet, an armature for said electromagnet, links pivoted to said armature and to a support relatively stationary to said electromagnet, the pivotal connection of said links upon said support being on the opposite side of the armature to which is the electromagnet, said links being of such length and so arranged that said armature shall be held always out of contact with the poles of said electromagnet, and a connecting-rod pivoted to the piano-action and to an extension of one of said links on the opposite side of its point of support to which is the armature, substantially as specified.

2. In an automatic attachment for pianos, the combination with a piano-action of an electromagnet, means for closing circuit electrically to energize the electromagnet, an armature for said electromagnet, links pivoted to said armature and to a support relatively stationary to said electromagnet, the pivotal connection of said links upon the support being upon the opposite side of the armature to which is the electromagnet, and a connectingrod pivoted to the piano-action and to an extension of one of said links on the opposite side of its point of support to which is the armature, the point of connection of the connecting-rod with the extension of the link being so located that the direction of a straight line drawn through the said point of connection and through the pivotal connection of the link upon its support, will approach more nearly to the direction of the line of pull of the connecting-rod, than will the direction of a straight line drawn through-the said pivotal connection of the link upon the support and the pivotal connection of the link with the armature, substantially as specified.

3. In an automatic attachment for pianos, the combination with a piano-action of an electromagnet, means for closing circuit electrically to energize the electromagnet, an armature for said eleetromagnet, links pivoted to said armature and to a support relatively stationary to said electromagnet, the pivotal connection of said links upon the support being upon the opposite side of the armature to which is the electromagnct, and a conn ectingrod pivoted to the piano-action and to an extension of one of said links on the opposite side of its point of support to which is the armature, the said extension being upwardly curved substantially as shown and for the purpose set forth.

4. In an automatic attachment for pianos, the combination with a piano-action, of a finger-key, adapted, under pressure, to operate said action, and having a recess in its under side, the mouth of said recess being contracted, an electromagnet, means for closing circuit electrically to energize said electromagnet, an armature therefor, a connecting-rod between said armature and said finger-key, said connecting-rod having its lower end se cured to said armature and its upper end arranged to enter the recess in said finger-key and having a head adapted to engage the said contracted mouth when said connecting-rod is depressed, but to be received within the recess, upon the independent depression of the finger-key, whereby the said connectingrod shall not at such times partake of such movement.

5. In an automatic attachment for pianos, the combination with a piano-action and a finger-key, adapted, under pressure, to operate said action, of an electromagnet, means for closing circuit electrically to energize said electromagnet, an armature therefor, a connecting-rod between said armature and said finger-key, a recess in said finger-key, a plate partially covering such recess, an orifice in said plate through which said connecting-rod is adapted to pass freely, and a head on the end of the connecting-rod of such size that it will not pass through said orifice, substan tially as specified.

In witness whereof I have hereunto set my hand this 4th day of April, 1899.

TIMOTHY B. POWVERS.

Witnesses:

HARRY T. Goss, GEO. N. CLARK.

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