US2934A - Pianoforte - Google Patents

Description

UNITED sTATEs PATENT oEEroE.

EDWIN BROWN, OF BOSTON, MASSACHUSETTS.

PIANOFORTE.

Specification of Letters PatentNo. 2,934, dated January 27, 1843.l

To aZZ 'whom t may concern Be it known `that I, EDWIN BROWN, of Boston, in the county of Suii'olk and State of Massachusetts, pianoforte manufacturer, and a citizen of the United States, have in vented an Improvement in the Action of Pianofortes, of which the following is a true, full, and exact description.

The object of my improvement is to obtain a more certain and perfect repetition of any note, to obtain a repetitionl by a slighter, and lighter touch of the key, and a more jready, easy and prompt action, and to prevent, what is termed the blocking of the hammer.

`The action of a pianoforte consistsy of the mechanical apparatus whereby the stroke of the hammer is given upon the wire and the sound produced. A distinct action belongs to each key' of the instrument.

In the annexed drawings a, a, a, a, Figure l represents alsection of the platform or base,` by which the' action is in part supported. The key ZJ, Z), is a Vlever workingupon its pivot at c, and putting the actionin motion when pressed down by the v finger. The jack, cZ, cZ, is framed into the key. Zhen the key is pressed downby the finger it acts through the `jack (Z, CZ, and its front CZ2, (Z2, upon the under hammer e, e, e, e. The front jack (Z2, is a lever turning upon its pivot at The under hammer acts upon the upper hammer g, g, g, g, and causes it to strike the wire Zt, Z1., and produce the sound.

The action as above described is in common use.- The method of applying the spring z', i, as described below, belongsv to the improvement made by me. It has a coil' at the left-hand part as seen in this drawing, forthe purpose of increasing its elasticity, and being free and not supported and not attached to' any part of the frame at that part. The block j, is fixed to the jack and moves with it and may be considered as part of the jack. One extremity of the' spring is attached to the top of the block, and thus in effect attached and fixed to the jack, and accordingly when the jack is moved by the motion ofthe key the m0- tion acts upon the spring, which rises and drops with the jack. The block j,is also one of my improvements. It is attached to the jack by a screw inserted through a verticalslot in the block, as is shown in Fig. 5,

and accordingly on turning the screw so as to loosen the block, theblock may be moved up or down and adjusted and fixed in any position desired by again screwing it down. The spring may be attached directly to the key, or the jack, and this regulating block thus dispensed with, but from experiment of the different modes of lixing the spring I think that of fixing it to the regulating block decidedly preferable. Aback view of this regulating block j, is given in Fig. 7 The regulating block may be attached to some fixture or vstandard upon, or projection standing up from the key, and the spring attached to the block thus adjusted, and this will be the same in effect asl attaching it to the jack. l/Vhen t-he regulating block or someequivalent contrivance for slackening and stifl'ening the spring and regulating its tension is not used, then the spring may be attached directly to the jack, or in front of or behind thecjack to the key or to some xture, standard, or projection from the jack or the key, or the spring may be secu-red at or through its coil, by a pivot to a block suitable for thev purpose, and such block be screwed or attached to the under side of the under hammer rail or frame m, m', and when the key is pressed do-wn the end of one branch of the spring be made to tra-verse in the grooved block 7c, as described below, and the end of the other branch to traverse in like manner in a groove inthe upper end of the regulating block y'. This will as has been ascertained by experiment, produce the same effect as attaching the spring to the jack. The grooves must of course be in the direction of the branch of the spring the end of which traverses in them respectively. It is evident-ly necessary that the spring should in this case, play freely at the pivot. Attached to the under hammer e, e, e, e, is the block 7c, which may be considered to be a part of that hammer; this isalso a part of my improvement. On the under side of this block Zc, is a beveled groove'extending quite across the block in thedirection of the key, that is, in the direction from front to rea-r of the pianoforte, which groove is lined or faced with soft leather. Fig. 8 represents a transverse section of this block 7c, exhibiting the form of the groove., The upper extremity of the spring z', z', lies in the angle of the groove, so that when by the motion of the key the is raised or lowered by the motion of the key, slides to and fro in the angle of this groove. The tendency of the spring when the jack is raised, obviously is to raise the lower hammer e, e, e, c, as its upper extremity bears gently upward against the lever of that hammer, but it is not the pee culiar function of this spring to raise the hammer and give the stroke upon the wire. this being done mainly by the action of the front of the jack (Z2, upon the lower hammer e, c, e, e, and this upon the upper hammer g, g, g, g in the manner heretofore in common use.

The function of the spring is to cooperate in raising the hammer, and to check and lighten their descent, whereby the performer is enabled to give a delicate repetition of the stroke at the elevation of the fingered part of the key, at half of its full sweep or vibration. Another function of the spring is to return the key to its proper' resting position, and accordingly by the use of the spring, the use of a weight for this purpose is dispensed with, or a lighter weight used. rlhe spring which I have used in my pianos is of number' l0 steel wire, but the size and material of the wire may be varied and the object of the impro-vement be still successfully effected. The tension and force of the spring is regulated by adjusting the block y', at a higher or lower position on the jack; The wire or rod. Z, Z, is also as applied by me, a part of my improvement. It is inserted into, and projects from, and is fixed to the jack and accordingly moves with the jack. lt terminates at the top in the form of a rightangled hook or elbow, as represented in Fig. 7. The return part or arm projects hori- Zontally across the lever of the lower hammer e, e, e, e, so that when the key of the piano is at rest, this horizontal arm or projection is in slight cont-act with the soft leather coating of the upper surface of that lever, and accordingly when the key of the instrument is inA its resting position, the lower hammer must be in its resting position upon the top of the front jack CZZ. As the jack is raised this hook Z, Z, is raised from off the lever of the lower hammer. The use of this hook is to secure the lower hammer to be in its proper resting position, when the key of the instrument comes to its resting position. rllhe side of the lever of the lower hammer, c, c, e, e, is cut away so as to make space for this hook Z, Z, to play backward and forward when the action of the instrument is put in motion, see Fig. G. This also is part of my improven'ient.

rllhe changing of the form ef the frame, a section of which is represented in drawings m, m, n, n, Fig. l, is also a part of my improvement, the common form of this part of the frame being quadrilateral with opposite sides about parallel to each other. The upper part of the rail heretofore in use corresponds in position with the upper surface of mine, marked m, m, in Fig. l, but the common rail, is much thicker vertically, the .lower part being removed in my improvement so as to make room for the spring. rlhe posterior part n, n, is attached to the other m, m, for the purpose of strengthening it and rendering it a firm and su'tlicient support for that part of the action which is connected with that part of the frame, the part a, n, is unscrewed and taken olf in order to come at and regulate the spring.

Another part of my impro-vement is the wire 0, 0, Fig. l, and the apparat-us p, Q, fr' and t. The wire is screwed or otherwise attached and xed to the front ack (Z2. The use of it is to cooperate in throwing olf the top of the front jack (Z2, from the under hammer, and disengaging it from that hammer when the stroke is given. Such disengagement is requisite in playing upon the instrument, and is intended always to take place in instruments in common use. This part of my improvement is intended to secure it more certainly.

ln the same drawing Fig. l, s, represents a section of the front rail which extends from one end to the other of the instrument, on which a part of the action is supported, Z, is a beveled projection inward, that is, backward from that front rail, and may be of the same piece of wood, or a piece glued, or otherwise attached and ixed to that front rail, the ripper surface of which projecting ledge is beveling, or oblique to the back of the rail, making the angle with it shown by the position of the block r, which is attac-hed and fixed to such ledge. A screw g, works through the block r, to the lower end of which screw is attached and fixed a cushion 7), faced with soft leather, which cushion is regulated by the screw, and may be proj ected downward or drawn upward by turning the screw. The curved end of the wire o, 0, as the jack CZ, tZ, is raised, comes in slight contact with the face of the cushion 72, and thus cooperates te throw forward the top of the front jack Z2 and disengage it from the under hammer.

l claim as my invention, and ask a patent forl. The use of the spring z', z', attached by means of a regulating block to the jack or the key, or, attached directly to the jack or key, or to a fixture or standard upon, or projection from, the jack or key, or to the rail or frame as above described, and for the purpose above described.

2. The block constructed and adapted, as above described, for Ythe purpose above described.

3. The grooved block c, constructed and llt) described, and as shown in the annexed 15 drawings, Fig. l, m, m, n, n.

7. The Wire 0, 0, and apparatus p, g', r, and t, constructed and adapted as above described and for the purpose above described.

In Witness Whereo:l I hereto set my hand 20 this nineteenth day of January in the year of our Lord one thousand eight hundred and forty-two.

EDVIN BROWN.

Vitnesses RICH. RoBINs, WILLARD PHILLIPS.

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