US1970A - Manner oe constructing the action pabt of pianofortes - Google Patents

Description

presses the standard N, and consequently the end of the damper P, upon the strings, and also forces down the end of the key lever. upon which the rod O rests. and elevates the key end thereof. Thus it will be seen that the arrangementI of the spring M. and the mode by which its power is applied to the adjacent parts, render the whole action exceedingly silnple and etiicient. The escapeinent of that part of the center block against which the end of the iiy abuts. may be so arranged that the vibratory inotion of the fly of the grasshopper may be very little in comparison with the same in other modes of action, thus abating almost entirely. if not rendering quite impcrceiliiblc. the noise eccasioned by its return upon the button F. lurthermore the quick repetition or trilling of the hammers in piano notes can be most beautifully and easily effected when the keys are nearly down by a slight, motion thereof. The arrangement of the action of common instruments, requires a great vibration of the keys to produce this operation.

The rear end of the key lever has a piece of wood m, n, connected to it, or applied to its upper side. One end a is confined in any suitable manner, while the other is left free to be raised or depressed by a screw 0. screwed through the end of the lever and abutting against the under side of the piece The upper surface t m, n, as seen in Fig. 1. of the piece mi, n, is covered with thin cloth or leather 79, upon which the rod a rests. The object of the scre.1 o is to regulatie and insure the action of the damper l" on the strings R.

In order to adjust the height of the jack to the hammer, l. afliX the bottom part of the saine upon a spring or piece of wood of z Fig. l., that has one end 7L properly secured by a screw, or otherwise. to the top of the hammer. The other end a. being left free; I insert a screw a through the key on its underside, the end of which screw shall bear or abut against the lower side of the spring 0, Therefore on turning 11p the screw, the spring and jack. can be raised and vice versa. lowered by the action or spring of the wood.

When it is desired to allow the strings a full vibration. while playing on the instru ment, or in other words to remove the dampers entirely therefrom so that they may not strike the strings although the hammers do, they may be raised by placing the foot on a pedal which is suitably connected to and raises the damper rail S. This damper rail extends along under the projection i of the upright standard N, having a strip of cloth r fixed on its top upon which the under side of the projection z' may be received when the damper rail is raised. Thus the elevation of the standard N, and cross bar or lever Q, throws the end or cloth t of the dainpers from the strings for the purpose above mentioned.

The uniehord action or change of the hannners and dampers from two strings to one etl'ceted by a pedal so applied as to raise the end u of a bent lever u v Qc Fig. 2. This lever has a fulcruin at e', and its end /w rests against a pin or projection m, from the rail l. Figs. l, and 2.

The rails i?. l, se@l Fig. l, are connected by a screw y, which passes through a vertical elongated slot cut through the former, and is scrrwed into the latter. The slot permits the damper rail S to be raised upward while when the slide rail I is moved laterally and horizontally. when the pedal is raised by the pressure of the lever u o 1.o on the projection ai. the screw f/ bears againsty one side of the slot ,a and carries at the same time the damper rail with it. The strings are stretched diagonally as represented in Figs. l. and 3 each hammer and damper bearing on two consecutive strings. Therefore when the hammers and dampers are moved sidewise they leave one of the strings, and their action is confined to the other alone. Thus when the end a of the lever u o w is raised, the rail I, hammers and dampers are moved laterally and on removing the foot from the pedal, a spring T properly arranged throws back the same.y thereby causing each of the hammers and dampers to act on two adjacent strings at every blow.

`urther1nore, another of my improvements consists in embedding the Wrest pin block A. Figs. 3 and et (or that piece of wood into which the straining Vins are driven), in a rectangular recess or oX a b c cl, Figs. 3 and 4, of the cast iron frame, so that the strain or pressure of the strings shall be received upon the bottoni c (Z of the same, upon or against which the lower side of the bar A rests. The wrest pin block is confined in said box or recess by a suitable number of screws passing through the back plate b o of the recess and screwed into the bar or block. One of the hitch pins is shown at f, Fig. 3, the string g proceeding therefrom running diagonally and connected to the straining pin z in the usual manner. The iron frame denoted in Figs. 3, t, is to stand perpendicularly and not to lie in a horizontal position as in the grand and square pianos.

llaving thus described my improvements l shall claimH l. The above arrangement of the parts of the action by which the spring M, after the strings are struck by the hammers, performs the three operations, of throwing back the hammer and preventing its recoil, throwing forward the damper upon the strings and depressing the rear end of the key lever consequently raising the opposite or key end, the whole being constructed and operating substantially as herein above set forth.

2. I also claim the mode of adjusting the end or cloth t of the damper to the string, by means of a piece of Wood or spring fm n applied to the rear end of the key lever, and

f raised or lowered by a screw 0; and also the mode of adjusting the height of the jack by a similar eontrivance applied to the same end of this key lever, the Whole being arranged substantially as above described.

In testimony that the above is a true de- 10 seription of my said invention and improvement I have hereto set my signature this eighth day of December in the year eighteen l hundred and forty.

TIMOTHY GILBERT.

litnesses z R. H. EDDY, EZRA LINCOLN, Jr.

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