FR2598244A1 - EXHAUST MECHANISM FOR A RIGHT PIANO - Google Patents

Abstract

The present invention relates to an escapement mechanism for an upright piano, characterised in that it comprises a repetition spring (16) in the form of a leaf spring bent in the shape of a U, one of the arms (160) or first arm of which is fixed to the upper part of the jack (7) and extends downwards along the latter, and the other arm (161) or second arm of which cooperates at its upper part with a repetition stop (19) integral with the beam (6) in order to bring back the jack (7) into the attack position, beneath the butt (10), in response to a minimal rise of the key (3) after the pressing of the latter.

Description

Escape mechanism for an upright piano t 'The present invention

relates to a

  exhaust mechanism for an upright piano.

  The piano, although it was developed relatively recently (around the 1700s), is the most universally used musical instrument. It is well known that pianos give sounds thanks to a set of steel strings stretched over a resonance table and set in vibration by the impact of hammers furnished with felt, each actuated by the compression of a touch of a keyboard which moves them between a rest position and a typing position in which they are in contact with the

  strings through an attack mechanism.

  There are two main types of pianos 15 which are the so-called "grand" pianos in which the strings are arranged horizontally and the so-called "upright" pianos in which the strings are arranged vertically. The advantage of grand pianos over upright pianos is linked to the fact that they have a mechanism known as "double escapement" which allows a player to come and strike a key immediately after it has been released; such an operation is indeed impossible in the case of conventional upright pianos where it is necessary to wait until the key has returned to its initial position before replaying a new note. This is a very serious drawback which means that some pianists, who play particularly fast, cannot play on

upright pianos.

  This drawback is linked above all to the configuration of the aforementioned attack mechanism which includes inter alia a damper which prevents the sound from being prolonged after actuation of the key, as well as the exhaust mechanism which allows the hammers to move back to their striking position and return to their rest position after compression of the

  corresponding button to allow a new actuation.

  The exhaust mechanism for upright pianos 15 comprises, for each of the keys, a bridge forming a lever cooperating with the key to bring the hammer into the striking position during the compression of the latter and on which are mounted, on the one hand, a fixed mechanical bed base, on which is articulated a nut carrying the hammer, and on the other hand, an approximately vertical exhaust upright movable between an attack position which it occupies when the hammer is in the rest position and in which it is located below and in engagement with the nut 25 to control its movement and, consequently, that of the hammer towards its striking position in response to the compression of the key, and a withdrawal position which occupies when the hammer moves from its

  rest position to its striking position or vice versa 30 and in which it is independent of the nut.

  The aforementioned mechanism gives the piano its softness of touch and its sensitivity, but has the drawback if it does not include an additional organ, of forcing it to wait until the key has returned to its initial position before compression so that the amount exhaust is again engaged with the nut, in the attack position, and so that we can again strike the strings with the hammer so

get a new sound.

  This drawback means that, despite their advantages linked mainly to their reduced size, upright pianos are always, if possible,

  neglected in favor of grand pianos.

  To remedy this drawback, attempts have been made for a long time to provide the exhaust mechanisms of upright pianos with additional members whose purpose is to accelerate, after striking, the return of the exhaust upright to its attack position. The devices of this type which have been proposed have, however, always proved to be relatively complicated, and none has in fact been able to give complete satisfaction. Among these devices, there may be mentioned by way of example, the addition below the exhaust post, of a helical spring coupled to a leaf spring disposed along the exhaust post and cooperating with a stop on which it is based; this system offers the advantage of making it possible to speed up to a large extent the return of the exhaust post to its attack position, but has the drawback of increasing the number of parts of the attack mechanism, which causes significant discomfort for adjusting the

88 piano keys.

  The object of the present invention is to remedy these drawbacks by proposing an escapement mechanism intended for a straight paino, making it possible to increase to a large extent the speed of return of the exhaust amount to its attack position, allowing as a result of bringing the characteristics of an upright piano closer to those of a grand piano, while

  limiting the number of additional parts required.

  To this end, the exhaust mechanism according to the invention is characterized in that it comprises a repetition spring with leaf folded in the shape of U and one of the branches or first branch of which is fixed to the upper part of the upright. exhaust (7) and extends from top to bottom along the latter and the other branch or second branch cooperates at its upper part with a repetition stop integral with the mechanical base to bring 10 the amount of exhaust in attack position, below the nut in response to a minimal ascent

  of the key after compression of the latter.

  Thus, for a minimal ascent of the key after being pressed, the repetition spring, which has been% 15 previously tensioned as a result of the compression of the key, exerts on the exhaust post a force allowing it to automatically return to its attack position by pushing the hammer towards the strings. This is a particularly simple configuration requiring only the addition of a single additional element, namely the repetition spring. According to another characteristic of the invention, the exhaust upright comprises, at its lower part, a rear bead connected to the bridge by

an exhaust spring.

  This characteristic makes it possible to increase the speed of return of the exhaust upright towards its

  attack position thanks to the return force of the exhaust spring.

  This configuration has been found to be particularly satisfactory from the point of view of the

easy adjustment of the piano.

  According to another characteristic of the invention, the repetition stopper is covered with fire: e

  next to the repeat spring. This characteristic increases the softness of the piano.

  The characteristics of the escape mechanism intended for an upright piano which is the subject of the invention will be described in more detail with reference to the appended drawing which is a diagram representing the mechanism associated with each of the keys of the piano. According to the figure, an upright piano is constituted by a set of steel strings 1, arranged vertically and stretched on a resonance table not shown. These strings are set in vibration as a result of the impact of hammers 2 lined with felt, which are each actuated by the compression of a key 3 on a keyboard. The compression according to arrow A of a key 3 causes the hammer 2 to move from a rest position shown in the figure, to a striking position in which it moves according to arrow B to come into contact with the cord 1 The movement of the key 3 is transmitted to the hammer 2 by means of an attack mechanism which includes numerous parts among which we can mention the damper 4 which prevents the sound from continuing when the key is left and the assembly I of the exhaust mechanism which is the subject of this patent and gives the piano its soft touch, its

  sensitivity and its ability to repeat quickly.

  According to the figure, the exhaust mechanism I comprises a bridge 5 forming a pivoting lever on which pushes the key 3 during its compression according to arrow A, and on which is mounted a fixed mechanical bed base 6 as well as an amount of exhaust 7 articulated around an axis 21 and comprising, in its part

  lower, a rear bead 22 connected to the bridge 35 5 by an exhaust spring 23. An exhaust bar

15 20 25 30 35

  pement 8 is, moreover, integrally connected to a metal rod 9 to the mechanical bed base 6.

  A nut 10 carrying an axis 11 at the end of which the hammer 2 is fixed is, moreover, articulated on the mechanical bed base 6; it carries approximately perpendicular to the axis 11 carrying the hammer 2, an axis 12 at the end of which is fixed a counter-catch 13 cooperating when the hammer 2 moves according to arrow B towards its striking position with a catch 14 which is fixed directly on the easel 5. At the end of the movement of the hammer 2 according to arrow B, the counter-catch 13 comes according to arrow C in contact with the catch 14 to always keep the hammer 2 at a small distance rope 1.

  In the rest position shown in the figure, the exhaust post 7 is in an attack position in which it is located just below the nut 10 and engaged by its end 15 with the latter to push it towards the front (arrow B) in response to pressing button 3 (arrow A). During this movement, as well as the corresponding movement of returning the key 3 and the hammer 2 to their rest position, the exhaust post 7 is in a withdrawal position in which its end 15 is not in contact with the nut 10, and therefore, in which it is impossible for the user of the piano to replay a new note by compressing the key 3 according to the arrow A. In accordance with the invention, it is precisely sought to reduce this period of time during which it is impossible to replay; for this purpose, a repeating spring 16 folded. U-shaped is fixed by the upper end 17 of its first branch 160 to the upper end of the exhaust post 7 and extends from top to bottom along the latter; the upper end 18

  of the second branch 161 of the spring 16 comes to bear.

  during the movement of the hammer 2 towards its striking position (arrowB), against a repeating stop 19 secured to the mechanical bed base 6 to which it is connected by a metal rod 24 and covered with a felt 20 facing this spring. Consequently, when the hammer 2 is in the striking position, the repetition spring 16 is under tension, and exerts when the key 3 is released, a force D on the exhaust post 17 which tends to bring it quickly back into its attack position in which it is below the nut 10 and cooperates at its end 15 with the latter to allow

replay very quickly.

  The invention therefore allows the pianist to be able to replay practically immediately after pressing a key thanks to the addition of a

  single piece (repeat spring 16).

- 8

Claims (3)

R E V E N D I C A T I O N S   1) Escape mechanism intended for an upright piano giving sounds thanks to a set of steel strings (1) stretched vertically on a resonance table and vibrated by the impact of hammers (2) furnished with felt actuated each by the compression of a key (3) of a keyboard which moves them between a rest position and a striking position in which they are in contact with the strings (1), by means of a mechanism attack comprising a damper (4) which prevents the sound from continuing after pressing the key (3), as well as the escape mechanism (I) which allows the hammers (2) to move to their striking position and quickly return to their rest position after compression of the corresponding button (3) to allow a new actuation, exhaust mechanism (I) comprising for each of the buttons (3) an easel '(5) forming a lever cooperating with the button (3) to bring the hammer (2) into the striking position l ors compression of the latter and on which are mounted, on the one hand, a fixed mechanical base (6) on which is articulated a nut (10) carrying the hammer (2) and, _ \ 0 -d'autre hand, an exhaust upright (7) approximately vertical, movable between an attack position ": which it occupies when the hammer (2) is in the position of -; -: rest and in which it is located below the nut (10) and engaged with the latter to control - _ its movement and, consequently, that of the hammer (2) towards -30 its striking position in response to the compression of the _: S key (3 ) and a withdrawal position which it occupies when the hammer (2) moves from its rest position to its striking position or vice versa and in which it is independent of the nut (10), escape mechanism   characterized in that it. has a repeat spring ---   tion (16) with blade folded in a U shape and one of the branches (160) or first branch of which is fixed to the upper part of the exhaust post (7) and extends from top to bottom along this last and of which the other branch (161) or second branch cooperates at its upper part with a repeating stop (19) integral with the mechanical bed base (6) to bring the exhaust upright (7) back to the attack position, below the nut (10) in response to a minimal ascent of the button (3) after compression of the latter. 2) Mechanism according to claim 1, characterized in that the exhaust upright (7) comprises, at its lower part, a rear bead 15 (22) connected to the bridge (5) by an exhaust spring (23). 3) Mechanism according to any one of   Claims 1 and 2, characterized in that the repeating stop is covered with felt (20) opposite 20 the repeating spring (16).