US170646A - Improvement in agraffes for piano-fortes - Google Patents

Description

sNITED STATES CHRISTIAN F. T. STEIN WAY, OF NEW YORK, N. Y.

IMPROVEMENT IN AGRAFFES FOR PIANO-FORTES.

Specification forming part of Letters Patent No. 170,646, dated November 30, 1875; application filed October 20, 1875.

.To all whom it may] concerni -Be it known that I, CHRISTIAN FR. THEo- DOR STEINWAY, of the city, county, and State of New York, have invented a new and useful Improvement .in Duplex Agraffes for Piano Fortes, which improvement is fully set forth in the following specification, reference being bad to the accompanying drawing, in which- Figure 1 represents a plan or top view. Fig. 2 is a longitudinal section. Fig. 3 is a similar section without the capodastro. Fig. 4 is a detached elevation of the capodastro.

Similar letters indicate corresponding parts. This invention consists in a capodastro secured from below in a bar cast solid with the metal frame of a piano-forte, in combination with agratfes secured in that portion of the meta-I frame which overlaps the wrest-plank, so that by the agrafl'es the strings are retained in the proper direction across the capodastro, and that the downward strain of the strings on the agraft'es-is counteracted by the upward strain on the capodastros. The capodastro consists of a screw-shank and a head of brass with a groove to receive a steel face, and also to give a hold for a screw-driver, by means of which the capodastro can be conveniently screwed home, and after it is secured in position the steel face is inserted, and thereby the bearing-points for the strings can be made narrow without permitting said strings to.

wear in.

In the drawing, the letter A designates the metal frame of a piano-forte, which is provided, near one end, with a strengthening-rib, a, that projects downward and bears against the wrest-plank B, in which are secured the tuningpins 1). The strings s extend from the tuningpins through agratfes c and under capodastros d, as shown more particularly in Fig. 2.

In the example shown in the drawing the agrafi'es are secured in the metal frame over the strengthening-rib a, while the capodastros are secured from below into a transverse bar, 8, which forms a part of the metal frame.

By means of the agraffes the strings are held in the proper direction across the capodastros, and at the same time the downward strain produced by the strings on the agraffes is counteracted by the upward strain against the capodastros, so that the metal frame is not liable to become distorted by the strain of the strings.

The capodastros are, by preference, made of brass, iu the form shown in Fig. 4, with a screwshank, al and heads (1*, said heads bein g provided with grooves 01 for the reception of steel faces 01 Before the steel faces are inserted, however, said grooves serveto afl'ord a hold for a screw-driver, whereby the capodastros can be screwed home, and after they have been secured in the required position the steel faces are driven in.

By the application of the steel faces I am enabled to reduce the width of the bearingsurfaces of the capodastros, so that the correct division or scale of the strings is not disturbed, and at the same time the strings are promoted from Wearin g into the faces of the capodastros.

The capodastros may be secured in the transverse bar 0; or in some cases they may be fastened directly in the wrest-plank.

What I claim as new, and desire to secure by Letters Patent, is-

1. A capodastro secured from below in a bar cast solid with the metal frame, in combination with agrafifes secured in the wrestplank, or in a portion of the metal frame bearing against said wrest-plank, substantially as shown and described.

2. A capodastro made of a screw-shank, d, and head 6?, which is provided with a groove to give a hold fora screw-driver and to receive a steel face,d substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand and seal this 15th day of October, 1875.

G. F. TH. STEINWAY.

Witnesses W. HAUFF, E. F. KAsTENHUBER.

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