EP0085266B1 - Harp with tone adjustment mechanism - Google Patents

Description

The present invention relates to a harp of the type comprising a set of strings stretched between an arm called a console and a resonator forming a soundboard, connected at the level of the abutment of the harp, and whose vibrating length is adjustable by means of pairs of forks able to pluck the strings and actuated by a mechanism, in particular with double movement, housed in a console and connected to pedals placed in the base of the harp.

In the field of musical instruments, the pedal harp, plucked string instrument, holds a special place, especially in chamber music. In its current modern form, it consists of a set of 38 to 48 strings, of unequal lengths, stretched between a console and a table secured to a box, at 45 ° from the plane of the strings. They include a vertical column connected to a pedestal including a pedals and of which the console and the table are joined together at the level of the abutment of the harp. In their so-called simple movement form and in their more recent form known as double movement, the known triangular harps comprise one or two rows of forks with two teeth offset along each string and intended, thanks to their action of pinching the string between them, to respectively shorten the strings by 1/18 ^* of the length of string remaining in vibration, so as to be able to provide the sound and the sharp sound from the basic sound, the flat.

In the harps known to date, seven pedals are provided, corresponding to the seven degrees of the range and making it possible to raise the strings in a semitone or tone and which have three positions associated with the flat, the natural and hash for each string. Each pedal actuates the forks associated with the different strings by means of a transmission mechanism currently consisting of a vertical rod housed in the column and connected, on the one hand, to the pedals and on the other hand, at its upper part, to a set of cams tilting on axes and connected by rods or levers, assembly rivets and chains to the different forks.

However, it has been found in use that such a fork actuation mechanism has significant drawbacks.

According to the system currently used, the rod operates alternately in compression and in traction, as do the control levers or rods located in the console, which has the effect that, on the one hand, there is a buckling of the vertical rods and the control levers by compression with harmful appearances of vibration, and on the other hand, when the holes of the assembly rivets are worn, the rivets move in their housings with each movement emitting a notable noise click-clack making mandatory what is called a long, expensive and random re-grouping.

In addition, the cams and levers are almost completely different delicate pieces of invoice, requiring precise manual adjustment and therefore a high cost price.

In addition, the manufacture of current harp mechanics uses more than 350 different parts and is therefore particularly expensive.

Patent DE-C-444 941 (L. Musolff) describes a mechanism for controlling the tension of the strings of a harp by means of pedals and cables linked to the strings. According to this document, the modification of the sound emitted by the plucked strings is obtained by varying the tension of the strings. This operating principle is relatively original, but clearly has the drawback of requiring a complex adjustment mechanism for each string. The invention discussed is clearly different from the Musolff harp, since we preferred the use of string plucking forks which make it possible to vary the length of vibration, and not the tension of the strings.

Patent DE-C-352 623 (OTTO) relates to a clamping mechanism for each string of a harp by means of a set of two superimposed forks whose rotation is caused, successively and differentiated, by a pulling cable 1. The connection between the traction cable to each of the two forks is constituted by two linkages each comprising a succession of cams rocking on axes and connected by links and levers, assembly rivets and chains. The transmission system thus described has many drawbacks, essentially linked to the large number of parts which it is necessary to use, and to the significant wear which occurs during use and which quickly harms the proper functioning of the together, producing in particular rapiderr << Mit unwanted extraneous noise.

This is why an object of the present invention is to solve the drawbacks mentioned above by reducing the number of parts used, the cost price of the instrument, while offering appreciable flexibility of use for the user, in particular by following the removal of unwanted noise.

This problem is solved using a harp according to the invention of the type indicated above, thanks to the fact that the mechanism for actuating the forks consists, for each of the seven degrees of the range, of a device double action transmission consisting of a first traction cable which is connected on one side to a series of first upper forks making a pluck of the associated strings to obtain the sound of the barrel, and on the other side to an organ of tilting control, of a second traction cable which is connected on one side to a series of second lower forks real sing a pinching of the associated strings to obtain the sharp sound, and on the other side to a pedal, said second cable actuating said tilting control member so as to translate the traction exerted on said cable in two successive angular movements of the forks higher, then lower.

Preferably, the tilting control members consist of a rotary cam disc, having a circular hub for returning the second traction cable, and a pivoting part connected to said first traction cable and resting on said cam disc.

In addition, according to a preferred variant embodiment, the cables are held in tension by means of return springs mounted between the abutment of the harp and one of the ends of each of said cables respectively.

Thus, as can easily be seen, this transmission system only works permanently in traction, without alternating effects of compression and traction and therefore silently.

According to the invention, the transmission device includes a compensation tensioner requiring the second traction cable to form at rest a course deviation, the length of which is greater than the length of peripheral displacement of the circular hub corresponding to the displacement stroke of the first traction cable (via the cam and the tilting member), the traction force of the return springs of the tensioner being less than the traction force of the return spring connecting said second traction cable to the abutment of the harp.

• la tonalité bémol, pour laquelle le mécanisme est au repos, et lesdites fourchettes ne pincent pas ladite corde ;
• la tonalité bécarre, pour laquelle le second câble de traction est actionné à l'aide de la pédale et d'une part entraîne en rotation sur environ un quart de tour la came qui repousse la barre et tire le premier câble de traction qui fait pivoter d'environ un quart de tour les bras des supports des fourchettes supérieures afin de pincer ladite corde au niveau supérieur en la raccourcissant d'1/18^e de la longueur restant en vibration, et d'autre part repousse le tendeur en tension sans que les supports des fourchettes inférieures ne bougent ;
• la tonalité dièse, pour laquelle la poursuite de l'actionnement de la pédale tirant le second câble de traction, d'une part fait pivoter sur environ un quart de tour les bras des supports des fourchettes inférieures, afin de pincer les cordes à un niveau inférieur en les raccourcissant d'1/18^e de la longueur restant en vibration, lesdits bras des supports des fourchettes inférieures venant en position parallèle auxdits bras des supports des fourchettes supérieures, et d'autre part entraîne la came en rotation sur un quart de tour, en laissant la barre pivotante en position inchangée du fait qu'elle est dorénavant en contact avec le profil circulaire de ladite came.

In addition, according to a preferred embodiment of the invention, the supports of the upper forks and the supports of the lower forks are connected respectively to the first traction cable and to the second traction cable by arms offset by the same angle by the same side of the strings plucked by said forks, and the cam has the shape of an appendage with parallel lateral sides tangent to the circular hub, so that each string can take its three tones:

• the flat tone, for which the mechanism is at rest, and said forks do not pinch said string;
• the natural tone, for which the second traction cable is actuated using the pedal and on the one hand rotates about a quarter of a turn the cam which repels the bar and pulls the first traction cable which rotates by about a quarter of a turn the arms of the supports of the upper forks in order to pinch said rope at the upper level by shortening it by ^1/18 of the length remaining in vibration, and on the other hand pushes back the tensioner without the supports of the lower forks do not move;
• the sharp tone, for which the continued actuation of the pedal pulling the second traction cable, on the one hand rotates the arms of the supports of the lower forks about a quarter of a turn, in order to pluck the strings at a level lower by shortening them by ^1/18 of the length remaining in vibration, said arms of the supports of the lower forks coming in position parallel to said arms of the supports of the upper forks, and on the other hand drives the cam in rotation over a quarter of turn, leaving the pivoting bar in the unchanged position because it is now in contact with the circular profile of said cam.

As can be seen, this system provides for each actuation mechanism on a very limited number of parts working in traction, which is far less than the number of parts used in harps known to date. It will be noted that all the levers or rods, the rods, their end caps and your rivets are eliminated and that a single cam is now used with a swivel bar, which considerably reduces the problems of assembly, adjustment and of course the price of come back.

• la figure 1 représente une vue d'ensemble en élévation latérale et en coupe partielle d'une harpe selon l'invention ;
• la figure 2 montre une vue en perspective à plus grande échelle du mécanisme d'actionnement des fourchettes utilisé dans la harpe de la figure 1 ;
• les figures 3, 4, 5 montrent des vues schématiques du mécanisme de la figure 2 dans les trois états possibles d'actionnement des pédales de la harpe ; et
• la figure 6 montre une variante préférée de réalisation du mécanisme de la figure 2.

Other characteristics and advantages of the invention will emerge from the description which follows by way of nonlimiting example and with reference to the appended drawings in which:

• FIG. 1 represents an overall view in side elevation and in partial section of a harp according to the invention;
• Figure 2 shows a perspective view on a larger scale of the fork actuation mechanism used in the harp of Figure 1;
• Figures 3, 4, 5 show schematic views of the mechanism of Figure 2 in the three possible states of actuation of the pedals of the harp; and
• FIG. 6 shows a preferred variant embodiment of the mechanism of FIG. 2.

In FIG. 1, representing an overall view of the harp according to the invention, the reference 1 designates the set of strings stretched between an upper console 2 and a soundboard 3 secured to a body 4. The console 2 is connected, by the vertical column 6, to the base 5 of the harp to which the table 3 and the body 4 are also integral. In the figure, only one of the actuation mechanisms of sets of upper forks is shown. 7 and lower forks 8 each comprising two teeth intended to pinch the associated strings 1 which they enclose, as well as a single associated pedal 9 for controlling such a mechanism, but it will be understood that the harp has a total of seven associated pedals at the seven degrees or notes of the scale and which can take a high position, corresponding to the flat sound and two lower positions (not shown) corresponding to the white sound and the sharp sound.

The mechanism consists essentially of a double action transmission device constituted by a bar 10 pivotally mounted in the column 6 and the upper end of which is connected by a first flexible traction cable 11 to the upper forks 7 and which rests with possibility sliding on a cam disc 12, on the circular hub 13 which circulates without sliding (or is secured in any other appropriate manner) a second flexible traction cable 14 connected to the lower forks 8 and which is connected by a yoke 15 to a crankset 16 pivoting about an axis 17 secured to the base 5. This crankset is connected to the pedal 9 and is pushed back to the high position - at rest - by a coil spring symbolized at 18.

In FIG. 1, the reference 19 designates axes on which the forks 7 and 8 are mounted, and the reference 20 designates a compensation tensioning axis, the role of which will be defined with reference to FIGS. 2 to 5.

Referring to the perspective view of FIG. 2 showing the essential part of the fork actuation mechanism, it can be seen that the pivoting bar 10 is rotatably mounted on a support bracket 21 secured to the upper part of the column 6. The cable 11 is connected to the upper end of the bar 10, in a lumen 22 thereof, by means of a suitable fixing member 23 such as a rivet or a weld. Otherwise, the cable can simply be tied to the bar 10. At its other end, the cable 11 is connected to the abutment (not shown) of the harp by a return spring 24. The cable 11 passes through a bore formed in an integral arm 25 axis 19 carrying a support 26 of a fork 7 whose teeth enclose the associated cord 1. The cable 11 is locked in position in the arm 25 by a clamping screw 27.

Furthermore, it can be seen that the bar 10 rests with the possibility of sliding on the cam 28 of a cam disc 29, the circular hub 30 of which has a groove (not visible) in which flows without the possibility of sliding, by being fixed there for example. by a clamp symbolized at 30a, the traction cable 14 connected at one of its ends by a return spring 31 to the abutment of the harp.

The cable 14 passes through a bore formed in an arm 32 integral with the axis 19 carrying a support 33 of a fork 8, the teeth of which enclose the associated cord 1. In addition, the cable 14 passes over a guide roller 34, the axis 35 of which is integral with the console 2, and around the tensioning axis 20 formed by a cylindrical element provided with a groove 36 and at the ends 37 of which are attached to the tension springs 38 lowering the axis 20 in the lateral openings 39 formed in parts of the console 2. Likewise the cable 14 is locked in the arm 32 by a tightening screw 40.

As shown in Figure 2 and as best seen in Figure 3, the bar 10, the arms 25 as well as the arms 32 of the supports 26 and 33 of the forks 7 and 8 are offset by the same angle - about 45 ° - to the right with respect to the respective cords 1 when the entire mechanism is at rest. The tensioning axis 20 is in the low position under the action of the springs 38. In addition the cam 28, which has - as shown - the shape of a projecting appendage with lateral sides 41, 42 parallel rectilinear and whose edge outer device 43 ′ is circular.

We will now describe the operation of the mechanism for actuating the forks 7, 8 with a view to plucking the strings 1 in order to adjust the vibrating length and therefore the flat, snaring or sharp sound, with reference to FIGS. 3 to 5.

The case of FIG. 3 corresponds to the case where the associated pedal 9 is in the high position, that is to say that the mechanism is at rest. The sound provided for strings 1 is a flat.

When the artist presses on the pedal 9 to lower it into a first position - corresponding to a woodcock, with a reduction of one semitone in the vibrating length of the rope - the pedal set 16 pulls on the flexible cable 14, which causes the cam disc 29 to rotate anti-clockwise about a quarter of a turn, with the following two effects:

on the one hand, the cam 28 rotates in the same direction and on the same angle the bar 10 which pulls on the cable 11 thereby bringing the arms 25 into the position shown in FIG. 4 by stretching the return spring 24, the forks 7 then plucking the strings 1;

on the other hand, the cable 14 is pulled while being brought into a rectilinear position because the springs 38 pulling down the tensioning axis 20 are designed looser than the return spring 31 and fail before the latter. link results that the arms 32 of the lower forks 8 do not pivot.

When the artist wishes to obtain the sharp sound, he presses the pedal 9 even more, which causes the cam disc 29 coming in the position shown in FIG. 5. The cable 14 is therefore pulled, so that the arms 32 of the forks 8 are pivoted by a quarter of a turn anticlockwise and that the forks 7 then pinch the strings 1 by shortening the vibrating length of the latter, while, as a result of the circular profile of the outer edge 43 of the cam 28, to which the bar 10 is tangent, the latter remains in its position in FIG. 4.

In Fig. 6, an alternative embodiment of the mechanism of FIG. 2, and according to which the bar 10 is replaced by a bent lever in T 44, of which a branch 45 (corresponding to the horizontal bar of T) is shaped in the same way as bar 10, while its branch 46 (corresponding to the vertical bar of T) is flexible and ends with a curved end 47. The outer face of this end is provided with a groove 48 in which the cable 14 circulates.

In this embodiment, the branch 46 plays the role of the compensating tensioner (20, in FIG. 2), while the tension springs 38 are eliminated, as is - possibly - the guide roller 34.

The operation of this variant of the actuation mechanism of the forks 7, 8 is similar to that described with reference to FIGS. 3 to 5. Indeed, at rest, the branch 45 of the bent lever in T 44 is in the same position as the arm 10 in FIG. 3, and the branch 46, by its end 47, presses the cable 14 into it impo the course deviation shown in this Fig. 3. When the artist presses on the pedal 9 to lower it into the first position, the crankset pulls on the cable 14, driving the cam disc 29 a quarter of a turn, the cam 28 of which turns the branch 45 of the lever 44 by bringing the arms 25 into the position shown in FIG. 4, the cable 14 stretching in its rectilinear position and pushing the branch 46 of said lever, following the operation of the mechanism corresponding in all respects to the description provided with reference to FIG. 5.

Naturally, in the case of the variant of FIG. 6, the tension springs 24 and 31 are appropriately dimensioned by exerting on their respective cables a tension greater than that produced by the flexible branch 46 of the T 44, so that at rest this cable 14 forms the desired course deviation by exerting on the end 47 of the branch 46 of the lever 44 only a reaction force less than the force exerted by the cable 11 on the lever 44 and maintaining the latter in the rest position, and so that, when the pedal is in the intermediate position, said end 47 exerts pressure on the cable 14 (which will drive the cam disc 29 when the corresponding pedal is released) but which is less than the tension of the spring 31 on this cable 14.

It can therefore be seen that the present invention provides a mechanism for adjusting the vibrating length of the strings of a harp, simpler than existing systems, requiring fewer adjustments and comprising significantly fewer parts than known devices, which gives it a more attractive cost price.

Claims (8)

1. A harp of the type comprising a set of strings (1) stretched between an arm called a console (2) and a resonator forming a soundboard (3), which is connected at the level of the abutment of the harp, the vibrating length of which may be adjusted by means of pairs of superimposed forks (7, 8), which are designed to grip the strings and which are actuated by a mechanism which is accommodated in a pillar (6), and which is connected to pedals (9) arranged in the pedestal (5) of the harp, characterised in that the mechanism for actuating the forks (7, 8) comprises, for each of the seven degrees of the scale, a double-acting transmission device comprising a first traction cable (11), which is connected on the one hand to a series of first upper forks (7) effecting a gripping of the associated strings in order to obtain a natural tone, and on the other hand to a rocking control member, and comprising a second traction cable (14), which is connected on the one hand to a series of second lower forks (8) effecting a gripping of the associated strings in order to obtain a sharp tone, and on the other hand to a pedal (9), the said second cable (14) actuating the said rocking control member, so as to convert the traction exerted on the said cable (14) into two successive angular movements of the upper and then the lower forks.

2. A harp according to claim 1, characterised in that the rocking control member comprises a rotating cam disc (12), having a circular hub (13, 30) for reversing the said second traction cable (14), and a pivoting rod (10), which is connected to the first traction cable (11), and which rests against the said cam disc (12).

3. A harp according to any one of claims 1 and 2, characterised in that the cables (11, 14) are maintained under traction by means of return springs (24, 31), which are mounted between the abutment of the harp and one of ends of each of the said cables (11, 14) respectively.

4. A harp according to claims 2 and 3, characterised in that the transmission device comprises a compensating tensioning device, comprising a shaft (20) having a groove (36) for receiving the cable (14), and two lateral return springs (38), which are connected to the ends of the shaft (20), which moves in two lateral elongated holes, the said tensioning device causing the second cable (14) to form, when at rest, a deviation from its path, the length of which is greater than the length of the peripheral displacement of the circular hub (13) corresponding to the path of displacement of the first traction cable (11), the tensile force of the return springs (38) being less than the tensile force of the return spring (31).

5. A harp according to claim 2, characterised in that the transmission device comprises a compensating tensioning device comprising a resilient bent lever (46), which is rigidly connected to the said rocking member (44), the lower end (47) of which lever comprises a receiving groove (48), the said tensioning device causing the traction cable (14) to form, when at rest, a deviation from its path, the length of which is greater than the length of the peripheral displacement of the circular hub (30) corresponding to the path of displacement of the traction cable (11).

6. A harp according to any one of claims 1 to 5, characterised in that each traction cable (14) is made integral with the arm (25, 32) of the supports (26, 33) of the forks (7, 8) by means of locking screws (27, 40), which penetrate a bore provided in the said arms of the said supports.

7. A harp according to any one of claims 1 to 6, characterised in that the first traction cable (11) is secured to the upper end of the pivoting rod (10, 44) by means of a rivet, welding, a screwed counternut connection or a single knot.

8. A harp according to any one of claims 1 to 7, characterised in that the supports (26) of the upper forks (7) and the supports (33) of the lower forks (8) are connected to the first traction cable (11) and the second traction cable (14) respectively via arms (25, 32), which are offset at the same angle on the same side of the strings (1) gripped by the said forks (7, 8), and the cam (28) has the shape of an appendix with lateral sides (41, 42), which are tangentially parallel to the circular hub (30) and the outer peripheral edge (43) of which is circular, such that each string (1) may adopt its three tonalities :

the flat tonality, where the mechanism is at rest, and the said forks (7, 8) do not grip the said string (1);

the normal tonality, where the second traction cable (14) is actuated by means of the pedal (9), and on the one hand rotates the cam (28) through approximately a quarter turn, which cam forces back the rod (10, 44) and pulls the first traction cable (11) which causes the arms (25) of the supports (26) of the upper forks (7) to rotate through approximately a quarter turn, so as to grip the said string (1) at the upper level, shortening it by 1/18 of the length which remains in vibration, and on the other hand forces back the tension device (20, 46) under tension, without the supports (32) of the lower forks (8) moving ;

the sharp tonality, where the action of actuating the pedal (9) pulling the second traction cable (14) on the one hand causes the arms (32) of the supports (33) of the lower forks (8) to rotate through approximately a quarter turn, so as to grip the said strings (1) at the lower level, shortening them by 1/18 of the length which remains in vibration, the said arms (32) of the supports of the lower forks (8) adopting a position which is parallel to the said arms (25) of the supports of the upper forks (7), and on the other hand rotates the cam (28) through a quarter turn, leaving the pivoting rod (10) in an unchanged position, such that it is now in contact with the circular profile (43) of the said cam (28).

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