EP0169957A1 - Butterfly valve for an accordion and its dynamic coupling to the key - Google Patents

Abstract

The valve is operated by a key and has a rectangular base frame containing a single keyhole aperture (2). The frame is mounted in the plane of the resonance casing (CA) and opposite to an equivalent air outlet opening. A butterfly valve (3) opens and shuts the keyhole by turning in the frame. It is spring-loaded shut by a coil spring (7). The respective key (N) forms a lever acting on a boss protruding from the side of the butterfly, so as to open the valve.

Description

The invention relates to a butterfly valve for accordion and the dynamic engagement thereof with the key.

In the construction of accordions, we know the traditional so-called "toppa" valves, made as a hammer actuated by the key by means of an angular lever with a very long arm, one end of which is integral with the hammer , while the other is attached to the button.

This valve, produced as a hammer, implies and requires a very careful execution of the profile of the section of the lever arm between the setting of the key and the hammer; this section, especially in certain keys, is of a particularly considerable length.

In the absence of the above execution, the support of the hammer on the plane of the sound box is not perfect and, therefore, the essential airtight closure of the valve is missing when the bellows blows the air with too much pressure defeating the return action of the spring installed in the setting of the button.

The aforementioned profile, needless to say, must be performed on a monthly basis by a workforce extremely specialized in the sector and, consequently, it will prove to be very expensive.

The spring installed in the setting of the key develops, because of the long lever arm between the key and the hammer, an excessive force which goes to the disadvantage of the agility of the keyboard.

This force, in fact, must always be able to guarantee the closing of the airtight valve by means of the pressure of the hammer, placed at the end of a long lever arm, on the sound box.

It has often been noted that, to make the holding of the valves as reliable as possible, we had to choose the force of the springs installed in the keyholes in such a way that we were forced to increase the thickness of the plane of metal (usually aluminum) of the sound box.

The pressure exerted by all of the hammer levers on the plane of the resonance box not only often forces the thickness of the above-mentioned plane to be increased, but it also imposes the production of several air outlet orifices for each valve in correspondence with the closing surface of the hammer.

Indeed, a single orifice, the surface of which equals the surface of the hammer, would excessively lighten the plane of the sounding board, already considerably subjected to the stresses of the spring pressure, as we have just described.

But several orifices instead of a single one, the surface of which equals that of the valve closing plane, cause a lower volume of air at the outlet to the detriment of the sound quality and a smaller opening of the bellows which would help the musician.

Another disadvantage of the so-called "toppa" valves with the hammer closure is that the surface of the hammer which presses on the plane of the sound box - where the outlet openings (orifices) have been made air from the valves and therefore from the sound - create an obstacle to the normal reflux of the air, which involves an alteration in the quality of the sound.

Finally, hammer valves have the disadvantage of beating on the metal background where the bells are installed and this disadvantage is particularly annoying in the recording room.

The role of the invention, therefore, is to provide an accordion valve whose perfect airtight closure does not depend on the careful profile of the control lever and which allows, during opening, the air outlet without any hindrance; whose return spring, when closed, is of considerably lower force than the spring of a traditional valve; and whose application costs are considerably reduced.

• - un châssis de base, qui présente une forme rectangulaire, à l'intérieur duquel on a ménagé une ouverture à boutonnière, puisque le susdit châssis est appliqué au plan de la caisse de résonance en corre spondance d'une autre ouverture équivalente pour la sortie d'air prévue dans celui-ci;
• - un paillon d'ouverture et de fermeture de la boutonnière susdite ménagée sur le susdit châssis, entablé en rotation, en correspondance de ses extrémités sur les petits côtés du châssis;
• - un ressort spiral, entablé au susdit châssis et agissant sur le susdit papillon, produisant la fermeture;
• - un téton saillant latéralement du susdit papillon, avec lequel la re lative touché agit dynamiquement, en guise de levier, pour l'ouverture de la vanne.

The invention can be fulfilled by making a valve constituted by

• - a basic chassis, which has a rectangular shape, inside which a buttonhole opening has been provided, since the above chassis is applied to the plane of the sound box in correspondence with another equivalent opening for the outlet of air provided therein;
• - A straw for opening and closing the aforementioned buttonhole formed on the aforesaid chassis, entablature in rotation, in correspondence of its ends on the short sides of the chassis;
• - a spiral spring, set in the aforesaid chassis and acting on the aforementioned butterfly, producing the closure;
• - a stud projecting laterally from the above-mentioned butterfly, with which the affected relative acts dynamically, as a lever, for the opening of the valve.

• - la fig. 1 est une vue perspective d'un dossier à clavier et d'une caisse de résonance sur le plan de laquelle on a appliqué une vanne tra ditionnelle et deux vannes selon l'invention;
• - la fig. 2 est une vue éclatée de la vanne selon l'invention;
• - la fig. 3 est une section transversale de la vanne selon l'invention représentée antérieurement sur la fig. 1.

Other characteristics and features will be illustrated below in more detail, with reference to a preferred embodiment shown, by way of non-limiting example, in the included drawings where:

• - fig. 1 is a perspective view of a keyboard file and a sound box on the plane of which a traditional valve and two valves according to the invention have been applied;
• - fig. 2 is an exploded view of the valve according to the invention;
• - fig. 3 is a cross section of the valve according to the invention previously shown in FIG. 1.

In freeze 1, a sound box (CA) with its keyboard backrest (ST) has been shown. We can notice, drawn in dashes, a van of the traditional type ("toppa") (VT) set in (F) on the back be placed on the keyboard by means of a lever (L).

In particular, it is important to fix attention on the length of the lever (L), on the many bends with elbow and side to which it was subjected, as well as on the three orifices (OR), drawn them also in dashes , arranged in the resonance box (CA) and on which the hammer (M) seals tightly under the action of a single spring, not visible in the drawing, installed in the recess (F).

Next to the traditional valve (VT), two valves are shown according to the invention: the first, which is generically indicated by the number (1), dynamically engaged with a white button (B); the second aligned along the same longitudinal axis as the first, which has been generically indicated by the number (1 ¹ ), dynamically engaged with a black key (N).

The two valves have a fundamentally identical structure and differ only by the dynamic use of their respective button in opening and closing, as we will describe more clearly.

The first valve (1) consists of a frame which has a rectangular shape inside which is formed a single buttonhole opening (orifice) (2).

In one of the short sides of the rectangle frame, a hole was drilled (4) and, on the opposite side, a cavity (5) was made to accommodate respect: a small nipple (4 ') and a small nipple (5 ') of a throttle valve (3) which, by pivoting on said stubs (4') and (5 '), can open and close _the Sealing the orifice (2) buttonhole.

The butterfly has a raised edge (6) on which the free end (7 ") clamps with a spiral spring (7) fixed by its other end to the valve frame.

At the end of the raised edge (6), directed towards the inside of the resonance box (CA), a stud (8) is provided for dynamic use with the inclined plane (10) of a sliding block (9). The sliding block (9) slides forward and backward on a step (11) formed on the long side of the chassis, in. correspondence of the raised edge (6) of the window (3) and, under the action of the key (B) and of the spring (7), it actuates the opening and closing of the valve.

The second valve (1 ') aligned with the first valve along the same longitudinal axis as the latter, is structurally identical.

The step of the chassis is on the extension of the step (11) of the valve frame 1) for the sliding of the sliding block (9).

The butterfly (3 ') of the valve (1 ¹ ) also has a stud (8 ¹ ) at the end of the raised edge (6') addressed to the keyboard file (ST).

But the dynamic use with the key (N) is directed thanks to the stud (8 ') without the intervention of a sliding block, as in the case of the valve (1).

From fig. 1, it can be noted that each of the valves (1, 1 ′) is controlled by using two springs which stress the button and the valve separately. This involves less stress on the resonance box (CA) compared to the traditional hammer valve and this guarantees a better hold of the latter, since it no longer depends on the perfect adhesion of the hammer on the plane of the sound box linked to the careful execution of the profile of the lever between the key and the hammer, but it only depends on the pressure of the spring (7) on the butterfly (3). The spring (7), in this case, while ensuring a more reliable airtight valve, also exerts less pressure on the resonance chamber.

In addition, this makes it possible to drill a single orifice for the valve instead of several separate orifices as in traditional valves, since there is no longer any problem of reducing the resonance chamber (CA).

This results in a larger volume of air at the outlet, therefore a better quality of sound and a smaller opening of the bellows, which helps the musician.

We always refer to fig. 1, it should also be observed that either the valve (1) or the valve (1 ') are dynamically engaged at their respective button (B) and (N) by means of levers (14), (14') much shorter compared to the levers of traditional valves, but above all it is essential to note that these levers, since they no longer have to be directly responsible for the holding of the valves, can be profiled much more easily and quickly by unskilled labor .

Thanks to fig. 3, it is possible to understand even better other features of the invention. It can be noted that the longitudinal wall (12) of the buttonhole (2) on the side opposite that of the raised edge (6) of the butterfly (3) is inclined up and down and towards the outside of the frame. This profile favors the exit of air when the valve opens.

The valve is held in place by the throttle valve (3) pressed by the spring (7) against the upper (13) and lower (13 ') edges of the chassis.

The step (11), on which slides the sliding block (9) is closed from the side by the wall of a successive pair of valves (1, 1 ') which will be placed alongside those which we have just described.

Finally, the end of the spring (7) is profiled with clamps (7 ") to promote better grip on the raised edge (6) of the butterfly (3).

What has just been described for a valve (1) with a white button (B) is naturally also valid for a valve (1 ') with a black button (N) with the only differences from the rogue (6) and dynamic use with the respective keys, as we have described and shown in the drawing.

All the other valves applied to the sound box next to those which we have described are identical to the above-mentioned valves.

The frames, preferably made of plastic, can be applied individually, or else be made in one piece keep on going.

From all that has just been described and illustrated, it can be seen that the invention has completely satisfied the aim which it had been proposed.

The valves according to the invention make it possible to eliminate the care necessary for the profile of the long lever arms between the key and the valve, saving material and 50% of the assembly time, but above all they make it possible to eliminate the hand d 'specialized work. These are two separate springs which control the valves, this is why the sound box is subjected to the stresses in a completely lower manner, which allows the realization of a single continuous orifice for each valve, with, by Consequently, a larger volume of air at the outlet, therefore better sound, and a smaller opening of the bellows.

The air resistance of the valves no longer depends on the adhesion of the hammer to the sound box entrusted to the execution of the profiles of a long arm, but it depends on the pressure of a spring which acts on the butterfly itself. valve.

The reflux of the outlet air no longer encounters any obstacle on the part of the hammer, no longer altering the sound.

The disadvantage of hammers beating on the plane of the sound box is eliminated.

Finally, the final test (the so-called tinning), relating to the alignment of the keys and the perfect holding of the valves, is eliminated.

The invention has been described and illustrated with reference to a preferred embodiment. It is understood that the embodiments, the arrangements, the dimensions and the proportions may be modified without departing from the scope of the present invention.

Claims (8)

1) Butterfly valve for accordion, and its engagement with the button, consisting of: - a base frame, which has a rectangular shape, inside which a single buttonhole opening (2) has been provided, since the above frame is applied to the plane of the sound box (CA) in correspondence with a another equivalent opening (2 ') for the air outlet provided therein; - A butterfly (3, 3 ') for opening and closing the above-mentioned buttonhole (2) formed on the aforesaid chassis, set in rotation (4, 4'; -), in correspondence of its ends on the small sides of the chassis; - a spiral spring (7, 7 '), set into the aforementioned chassis and acting on the aforementioned butterfly (3, 3') producing the closure; - a stud (8, 8 ') projecting laterally from the aforementioned butterfly with which relative key (B, N) acts dynamically, as a lever, for the opening of the valve (1, 1'). 2) Butterfly valve according to claim 1), characterized in that the control of each valve occurs thanks to the cooperation of two springs which act separately, one on the key (B, N) and the other ( 7) on the butterfly (3, 3 ') of the valve. 3) Valve according to claim 1), characterized in that the air blown by the bellows exits through a single orifice (2) whose surface is equal to that of the butterfly (3.3 '). 4) Valve according to claim 2), characterized in that the free end of the spring (7, 7 ') is profiled with clamp (7 ") to improve the attachment to the raised edge (6, 6') of the butterfly (3, 3 '). 5) Valve according to claim 1), characterized in that the longitudinal part (12) of the buttonhole (2) of the side opposite to that of the raised edge (6, 6 ') of the butterfly (3.3') is inclined from top to bottom and outwards, to favor the exit of air. 6) Valve according to claim 1), characterized in that the air retention is ensured by the butterfly (3, 3 ') pressed by the res comes out (7, 7') against the lower edge (13) of the buttonhole (2) of the chassis and on the upper edge (13 ') thereof. 7) Valve according to claim 1), characterized in that the opening of the valve (1) controlled by the white button (B) occurs by means of the push forward, from the short arm of the lever ( 14) of the key (B), of the sliding block (9) which, thanks to its inclined plane (10), pushes up the stud (8) of the butterfly (3) by lifting it against the action of the spring (7). 8) Valve according to claim 1), characterized in that the opening of the valve (1 ') controlled by the black button (N) occurs by the direct action of the short arm (14') of the button ( N) which pushes up the stud (8 ') of the butterfly (3') by lifting it against the action of the spring (7 ').

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