US890087A - Piano-action. - Google Patents

Description

1' UNITED P TENT OFFICE.

ROBERT OPPITZ, OF KOBLENZ, GERMANY.

PIANO-ACTION.

Improvements in Piano-Actions, of which the following is a specification.

This invention relates to a piano-action provided with a repetition spring arranged. on the upper part of the jack, and so con structed that the adjustment of the power of the said spring can be effected independent of the adjustment of the regulating button on the counter-check which determines the distance that the hammer falls. This object is accomplished by inserting the spring into a slot of the jack, so that it has always a fixed fulcrum in the jack, whereby its free arm which acts upon the hammer has always the same position relatively to the jack, the adjustment of the power of the spring being effected by means of its other arm. The adjustment of the distance through which the hammer is to recede from the string is effected independently of the repetition spring by means of the adjusting button mounted on the counter-check and under which the spring engages after the keyhas been struck. In this way the hammer is always sustained ready for action, even during repeating, as the distance through which the hammer is to fall back may be readily adapted to all requirements without changing the power of the repetition spring.

In the accompanying drawing: Figure 1 is a side elevation of a piano action embodying my invention, showing the normal position of the parts; Fig. 2 is a similar view, showing the position of the parts after the key has been lightly struck; Fig. 3 a similar view, showing the position of the parts when the key has been forcibly struck, and Fig. 4 a detail of part of the jack, showing the repetition spring in position.

When the key a, is struck, the wippen b, is raised in known manner and the hammer e, is brought against the string 8, by engagement of the jack 0, with the hammer-butt d, pivoted at 90. The repetition spring g, mounted on the upper part of the jack, has the position shown in Fig. 1, relatively to the Specification of Letters Patent.

Application filed February 16, 1907.

Patented June 9, 1908.

Serial No. 357,661.

counter-check h, in the normal position of the action.

WVhen the key is lightly struck, the repetition spring g, engages beneath the adjustable button f, of the counter-check and prevents the hammer from completing its full return movement; at the same time the jack c, is moved towards the button f, by contact of its tail m, with button Z, (Fig. 2). hen the key has been heavily struck, spring g, will be so bent that counter-check 7t, engages backcheck 1, while the jack engages with the upper notch in. the hammer-butt, (Fig. 3). Button f, can be raised or lowered by turning its screw spindle i, which works in the counter-check h, so that the return of the hammer can be regulated.

When the finger is raised ever so little from the key, whether the touch had been light or heavy, the hammer e, is freed and is driven upwards by spring g; the jack 0, and the spring g, remain first in the position assumed when the key was struck, while the hammer itself is merely raised by the spring In this way the aok c, which is moved backwards by a helical spring n, acting on its tail m, can engage beneath the hammer-butt, so that the hammer is again ready to be actuated. These movements occur as already stated, by the slightest raising of the finger off the key and without the necessity of with drawing the bigger completely.

The repetition spring g, is preferably made of the form shown in Fig. 4, so that its tension can be adjusted in a simple manner. It is bent at p, and engages in a rearwardly narrowing recess or slot 0, of jack 0. By pushing the spring into or partly withdrawing it from slot 0, its power may be readily altered without changing the elevation of its operative end in relation to the jack 0, as indicated. by dotted lines in Fig. 4.

I claim:

1. A piano action provided with a jack, a spring carried thereby, means for adjusting the power of the spring, a counter-check, and a regulating button carried thereby and lo cated so as to be engaged by the spring, substantially as specified.

2. A piano action provided with a slotted jack, a bent spring seated therein and having my name in the presence of two subscribing an upper and a lower arm, means for achustw1tnesses. mg the power of the upper arm, a counterl J check, and a regulating button carried there- ROBERT O1 PIrl/J' 5 by and loeateclso as to be engaged by the Utnesses:

upper spring-arm, substantially as specified. BESSIE F. DUNLAP,

in Witness whereof, I have hereunto signed 'l'JoUIs 'VANDoRP.

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