US270914A - Dor steinwat - Google Patents

Description

(No Model.)

0. F. T. STEINWAY.

PIANO ACTION.

Patented Jan. 23,1883.

N. PETERS. Pbnlo- Mnpher. wilhiflml. u. c.

PATENT O FICE.

CHRISTIAN F. THEODOR STEINWAY, OF NEW YORK, N. Y.

PIANO-ACTION.

SPECIFICATION forming part of Letters Patent No. 270,914, dated January 23, 188.

Application filed July 15, 1882. (No model.)

T 0 all whom it may concern:

Be it known that I, CHRISTIAN F. THEO- DOR STEINWAY, of New York, N. Y., have invented a certain Improvement in Piano-Forte Actions, of which the following is a specification.

My improvement relates to that class of piano-forte actions in which the movable trains of levers and links for actuating the hammers respectively are operated by being pushed upward.

It is the object of my invention to diminish the weight borne upon the inner ends of I ac the keys when such actions are at rest. complish this by carrying a portion of such weight upon expanding springs which derive their support from the action -frame. The springs which I employ for this purpose are of a peculiar shape, which especially adapts them for adjustment to the desired object. By thus relieving the keys from a portion of the weight of the action I am enabled to dispense with one or more of the counterpoiseweights heretofore introduced into the forward parts of the keys. Therefore a lighter touch suflices to depress the key, and the action, as a whole, is increased in sensitiveness and. delicacy.

The accompanying drawing, which illustrates myimprovement applied to apiano-forte action substantially like that shown and described in lteissued Letters Patent No. 9,013, dated December 30,1879, granted to me for an improvement in piano-forte actions, is a vertical section of a piano-forte action-frame, showing inelevation one of the keys and one of the trains of levers and links by which motion is transmitted from thekey to the hammer; also showingin side elevation my spring for relieving the key from a portion of the weight of the action. I

The drawing exhibits a section of the keyboard bed A, to which is secured the usual balance-rail, 13, provided with the balance-pin a, which forms the guide for the key 0. The

key is provided with the pilot-screw c, the rounded head of which bears upon the cushioned under surface of the shoulder 0', projecting downward from the under side of the intermediate or balance lever, d. The lever d carries thejack c, by means of which motion is transmitted to the hammer-arm H.

The drawing also represents the actionfraine, consisting of the metallic standards D, to which are fastened the tubular metallic rails E. ening the standards at the bottom, and for adjusting the various parts of the action. When the parts are at rest a portion only of the weight of the action is borne upon the head of the pilot-screw c. The remaining portion is borne, through the medium of the relief-spring N, upon the cushioned bar 0, affixedto the rail E of the action-frame. The relief-spring is a wire coiled to form the eye a for the reception of the pin P, insertedtransversely through the side walls of the groove 12, formed in'the side of the shoulder c. The ends of the coil are prolonged to form respectively the upper arm, n, and the lower arm, of, of the relief-spring. The upper arm, it, is sinuously curved in a vertical plane, as shown, and its free end bearsupon the bottom of the groove 1), formed in the under side of the balance or intermediate lever, d. The lower arm, n is bent in a long curve, presenting its convex side downward. Its free end is formed into the hook Q, to receive the bolster or link q, affixed to the intermediate lever, cl. \Vhen the parts are at rest, the arm n bears upon the cushioned surface 0 of the bar 0, which is secured to the action-frame rail E by a suitable number of screws, one of which, is shown in the drawing. As the forward end, 0, of the key is depressed, and the intermediate lever and its connections pushed upward, the lower arm, n rolls over the curved surface of the cushion 0 without slipping thereon, and is finally caught and held by the bolster q.

By varying the curvature of the arms, especially the curvature of the upper arm, n, the effective lifting force of the relief'spring may be adjusted with the greatest nicety.

By the use of my relief-spring one or more of the usual counterpoise-weights, like the weight R, inserted into the forward part, 0, of

The usual provision is made for fastthe key 0, may be dispensed with, thus dimin- ICO 5 cushioned bar 0, as and for the purpose set I claim as my invention in a piano-forte 210- 3. The relief-spring N, carried by the inter- 10 tion substantially such as described mediate level, (1, in combination with the boll. The intermediate or balance lever, d, and ster q, substantially as described.

the relief-spring N, in combination with the i O. F. THEODOR STEINWAY.

forth.

2. The lower arm, 12 of the relief-spring N, Witnesses: curved as shown, in combination with the H. A. OAssEBLER, J12,

curved surface of the cushion 0. i JACOB ZIEGLER.

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