US592840A

US592840A - Leopold sturzwage

Info

Publication number: US592840A
Authority: US
Publication date: 1897-11-02
Anticipated expiration: 1914-11-02

Description

(No Model.)

L. STURZWAGE.

PIANO MECHANISM.

No. 592,840. Patented Nov. 2,1897.

UNITED STATES a'rnnrr rites,

LEOPOLD STIIRZWAGE, OF MOSOOVV, RUSSIA.

PIANO MECHANISM.

SPECIFICATION forming part of Letters Patent No. 592,840, dated November 2, 1897.

Application filed June 22, 1897. Serial No. 641,804. (No model!) To aZZ whom it may concern.-

Be it known that I, LEOPOLD STiiRzWAeE, a subject of the Emperor of Russia, residing at Moscow, Russia, have invented certain new and useful Improvements in Piano Mechanics, of which the following is a specification.

The present invention relates to repeating mechanism for grand pianos and involves the peculiar construction of the jack and fly-jack, by means of which an even, light, and noiseless stroke or blow, as also reliability of repetition, is obtained.

In order to render the present specification more easily intelligible,reference is had to the accompanying drawings, in which similar letters of reference denote similar parts throughout the several views.

Figure 1 is a side elevation of the device, showing the hammer down. Fig. 2 is a similar elevation drawn to a larger scale with the hammer raised, and Fig. 8 a front elevation of Fig. 2.

The jack a is pivoted at a and provided at one end with a cushion a on which the stem 1) of the hammer rests, said jack carrying the fly-jack c at the opposite end, having its pivot arranged approximately over the rigidly-fixed striker-pin d. The end of the fiy-jaok is bifurcated and embraces the jack a, enabling a small spring e, mounted on the jack a, to pass between the bifurcations and engage a cord-eye fastened on the lower surface of the projecting foot 0 of the fiy-jack. The upwardly-extending surface of the foot 0 is provided with a cushion and is adapted when the key is struck to engage the fixed stop f, which is adjustable by means of a screw f and operates to throw the fly-jack out of engagement with the knob b of the hammer-stem. The upper part of the fly-jack is narrowed to enable it to pass through an orifice g of the repeater-lever g, in which orifice it has sufficient play to prevent friction. Above the orifice the fiy-jack is again widened, so that its upper edge is of the same width as the knob or projection b on the stem of the hammer and also as the raised shoulder g of the repeater-lever g.

lVhen the key is struck, the hammer b is first raised by the fiy-jack 0 until it has nearly attained a horizontal position, when the knob 1) passes onto the shoulder 9 Fig. 2, the fly-jack being thrown out of engagement by the stop f without causing the slightest fricthe fly-jack c from being thrown too far back from the knob Z2. The said screw 2' also forms a stop for the lever g itself after it has been thrown out of engagement. The spring 7a, which is bent round at an angle, is adjustable in the jack a by means of a screw Said spring engages a cord-eye fastened to the lever g. The adj Listing-screw enables an exact adjustment of the spring is for the heavier bass and lighter soprano hammers.

The raised shoulder g of the repeater-lever enables the fiy-jack to be made broader at its upper end, which has the effect of preventing the same from getting pressed into the knob 11, as has hitherto been the case, thus causing considerable friction on the disengagement of the fly-jack. Both the jack and the repeater-lever will thus be disengaged without causing any friction whatever, so that no noise whatever can be caused by the present mechanism, since the springs will work entirely noiselessly in their cord-eyes.

I claim as my invention- 1. In a repeating mechanism for grand pianos the combination of the jack a with the repeater-lever g mounted on the jack and having a raised shoulder g and an orifice g before said shoulder, and a fiy-jack c mounted on the jack a, the said fly-jack passing through the orifice g of the lever g and having its upper edge widened to the Width of the knob b of the hammer-stem, substantially as described.

2. In a repeating mechanism for grand pianos the combination of the jack (1 the repeater-lever g with slot g end shoulder g and the fly-jack 0 having a widened upper edge, with the stop f disengaging the fiy-jack in its upward movement and the stop c screwed in the repeater-lever g, the stop c limiting the backward movement of the fly-jack, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

LEOPOLD STURZWAGE.

Witnesses:

. Aueusr MtIHLE,

WLADIMIR ZIOLECKI.