US1216701A - Grand-piano action. - Google Patents

Description

C. KNOCH.

GRAN D PIANO ACTION.

APPLICATION FILED MAY 31. 1916.

1,216,701.- Patented Feb. 20,1917.

anvmwm Carl '(uoolg CARL KNOCH, OF NEW YORK, N. Y.

GRAN D-PIAN 0 ACTION.

Application filed May 31, 1916.

To all whom it may concern:

Be it known that I, CARL KNOCH, a subject of the Emperor of Germany, residing at New York city, county and State of New York, have invented certain new and useful Improvements in Grand-Piano Actions. of which the following is a full, clear, and exact description.

This invention relates to improvements in grand piano-actions, but pertains more particularly to the hammer or hammer-shank operating devices which are set in motion when a key is depressed. My invention is directed mainly to improve that part of the action intended to prevent the rebound ing of the repetition lever and also to prevent the chattering of the pivotally connected repetition lever and its support.

I will now proceed to describe my invention in detail, the essential features of which will be summarized in the appended claim, reference being had to the accompanying drawing, forming part hereof, wherein the single view is a sectional. side elevation of that portion of the hammer action of a grand piano embodying my improvements.

As my improvement has for an object to improve the hammer actuating device of a grand piano, I have illustrated only that portion of the action of such a piano which will fully disclose my improvement.

In the accompanying drawing, the nu meral 1 indicates the hammer shank of a grand piano action, the numeral 2 indicates the repetition lever of such an action, 3 the support for the repetition lever and 4 the jack. The hammer actuating mechanism, indicated in a general way by the numeral 5, consists of the said support 3 and repetition lever and jack. When a key is depressed (a portion of such a key being indicated by 6) the hammer actuating mechanism 5 will be swung upwardly, the hammer-shank 1 being also swung upwardly, due to a contacting felt shoe 7 which is carried by the shank 1. The shoe 7 is located in alinement with the free end of the jack 4 which passes through a slot 8 in the repetition lever 2.

When a key 6 is depressed, the hammer actuating mechanism 5 will be swung upon the pivot 9, all of the members 2, 3 and 4 moving together, until the free end of the repetition lever 52 comes in contact with the Specification of Letters Patent.

-turned to normal position by a small Patented Feb. 20, 191 '7. Serial No. 100,933.

stop 10. At such time the repetition lever will come to rest, but the jack 4 will continue to move upwardly and raise the shoe 7 off the repetition lever 2; at about this time the arm 11 of the jack will come in contact with the stop 12. A continued upward movement of the support 3 will cause the jack 4, or rather the end 13 thereof, to move away from the shoe 7, thereby allowing the hammer-shank 1, and hammer 11 thereof to drop. The jack 4 is pivotally connected at 15 to the support 3.

When playing rapidly the movement of the hammer actuating mechanism 5 is of course also rapid and more or less snappy; hence there is a tendency for the repetition lever 2 to chatter, said repetition lever being pivotally connected at 16 to the support- 3. When a, key is depressed and the hammer actuating mechanism 5 swung upwardly, the repetition lever 2 will be the first element to come to rest against its stop 10. Then the jack will escape from the shoe 7 and the hammer will drop. While the repetition lever 2 is at rest, the support 3 will continue to swing upwardly. After the jack 4 has been tripped, it will be respring 18. A stop 19 attached to a part of the fixed supporting frame of the mechanism determines the rest position of the jack 4.

To prevent the rebound and chattering of the repetition lever 2 as well as the support 3, I interpose between said parts a cushioning or shockabsorbing element, which in this instance consists of a coil spring 20 seated at one end thereof in a socket 21 in the support 3 and at the other end around a lug 22 on the repetition lever 2. The spring 20 cushions the rebound of the repetition lever when it strikes the stop 10 and also prevents the chattering thereof. It also acts to keep the support 3 and capstan screw 23 on the key 6 reliably in contact, thus aiding gravity in holding said support on its fulcrum without displacement. The spring 20 is placed under an increased pressure after the repetition lever strikes the stop 10, whereupon it will be slightly compressed. While in the normal position, the spring 20 will tend to force the repetition lever and support apart, but will exert more pressure upon the support 3 after the repetition lever strikes the said stop 10. Hence at the time when rebounding or chattering usually takes place during rapid playing, the spring 20 will be exerting its greater pressure. Certain of the illustrated parts have not beenreiterredto, as their .hinction and action is well known to those skilled in the art. The stop 2; acts to maintain the repetition lever and its support in a certain fixed relationship while the stop serves to maintain the jack 4: and shoe 7 in alineinent during their periods of idleness. In other words, the stop 241- prevents the pressure exerted by the spring 20 from being transmitted to the shoe 7, throughthe repetition lever during the period of idleness oftheihammer actuating inechanismfi.

Having'now described my invention what Copies of this patent may be obtained for five cents each, by addressing the I claim and desire to secure by Letters Patent is:

A. v grand piano action which includes hammer-actuating mechanism comprising a rail, a repetition lever pivoted thereto, a support underneath the lever and pivoted to the latter and having a downward projection located to rest on the capstan screw ofthe key and a spring between said lever and support bearing directly against both these-parts and tending to separate them.

Signed at New York city N. Y., this 29 day of May, 1916.

CARL KNOCH.

"VVitnesses EDWA D A. JARVIS,

MAURICE BLoon.

Commissioner of 1 Eatents,

Washington, In 0;

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