Patent Application
20140366705
This application claims priority from European Patent Application No. 13172119.3 filed 14.06.2013, the entire disclosure of which is incorporated herein by reference.
The invention relates to a method for adjusting the vibration frequency range of a sound producing device with one or more vibrating tongues or strips.
The first musical box, created in 1796 by Antoine Fabre, was formed of a cylinder provided with pins and a set of tongues defined as a musical pin-barrel. When the cylinder rotates, the pins on the cylinder are arranged to lift and then release, in a well defined order, the steel tongues of the pin-barrel, which are perfectly tuned, to reproduce a tune. As they fall again, the tongues vibrate and thus each indirectly produce one sound from a melody to be played.
This type of musical box with the aforementioned sound producing device can be integrated in jewellery boxes or in toys or also in watches.
U.S. Pat. No. 2,755,697 may be cited in this regards, which discloses a tongue carried by a comb, which is clamped between a support piece and a clamp.
To adjust the acoustic frequency produced by the tongue, a load member can be added to said tongue. This load member is movable and, depending on the position of said load member along said tongue, the frequency and therefore the sound produced is modified.
U.S. Pat. No. 3,013,460 discloses a set of tongues connected by a common comb. The comb is immobilised on a base, where it is supported and held by a clamp using screws traversing the clamp and the comb. To tune the tongues, instead of adding a load member, the tongues are machined in order to remove material.
To secure this set of tongues of different lengths to a support or a base, a clamp is usually used, which is applied to the comb and which is held in place by screws, whose shafts traverse pierced holes in the clamp and the comb and each cooperate with a threaded sink, comprised in the support. The clamp only presses on the comb and the pierced holes are made to the diameter of the screw shafts with operating play.
In principal, the tongue lengths are calculated each to produce a determined frequency of a sound and no action is necessary in terms of an adjustment. However, as indicated above, it is possible to adjust the vibration frequency of each tongue by adding a load member to the tongue in U.S. Pat. No. 2,755,697 or by removing material in U.S. Pat. No. 3,013,460. This is then a fine adjustment.
The solution of U.S. Pat. No. 2,755,697, of adding a sliding load member, is difficult to implement in the case of a device for incorporation in a watch, due to the miniaturisation required. Further, it is unreliable, as it is difficult to secure the load member to the tongue, given than the vibrations tend to unscrew the screw securing the load member.
The solution set out in U.S. Pat. No. 3,013,460 is more reliable, but requires subjecting the pin-barrel to a further machining operation.
Beyond these fine adjustments, when it is desired to work in a different frequency range, another pin-barrel has to be produced with different tongue lengths. A pin-barrel having its own tongue lengths must thus be produced each time, which is a drawback.
The invention proposes to provide a solution to the aforementioned drawbacks of the state of the art.
The invention therefore relates to a method for adjusting the vibration frequency range of a sound producing device with one or more vibrating tongues, the device including an assembly formed of a comb extended by at least one vibrating tongue, said comb having at least one hole for the securing thereof to a support by means of a support jaw and a tightening element traversing the support jaw and the hole of the aforecited comb, said method being characterized in that the frequency range is adjusted by reducing the free length of the vibrating tongue or tongues by the localised clamping of the tongue or tongues between the support jaw and a local counter-support.
The invention also concerns means for implementing the adjustment method, the means including a sound producing device with one or more vibrating tongues, which includes an assembly formed of a comb extended by at least one vibrating tongue, said tongue has at least one hole for the securing thereof to a support by means of a support jaw and a tightening element traversing the support jaw and the aforecited hole of the jaw, these means being characterized in that they include means for reducing the free length of the vibrating tongue or tongues by the localised clamping of the tongue or tongues between the support jaw and a local counter-support.
One advantage of the sound producing device provided with means of adjusting the frequency range of the musical pin-barrel lies in the fact the general length of the vibrating tongue or tongues may easily be adjusted without having to change the pin-barrel. This makes it possible to adapt the frequency range, via at least one jaw fixed to a support, and via a counter-support, by locally clamping an end portion of the tongue or tongues, when the comb of the pin-barrel is secured to the support of the device. Thus, it is easily possible to create a standard pin-barrel while enabling the sounds generated by the tongues of the pin-barrel to be adapted for mounting, for example, in a watch.
Advantageously, these adjustment means of the sound producing device are also arranged to improve the securing of the pin-barrel with supports provided above and below the comb and on an end portion of the tongues. Thus, acoustic transmission to the radiating components of the watch is improved.
The invention will be understood with the aid of the following description given by way of non-limiting example with reference to the drawings, in which:
Referring to the Figures above, a device 1 is shown with vibrating tongues for producing music including a set 2 of vibrating tongues 2C of different lengths to produce a range of sounds. Vibrating tongues 2C are all connected at one end to a comb 2A to form a comb-like structure. This set of tongues is also called a pin-barrel, whose tongues and comb are made in a single piece of material. It is, however, possible to envisage creating a single tongue connected at one end thereof to a securing comb.
A means (not shown) makes it possible to move and release the free ends of the tongues in a programmed manner to produce a melody. This means may be a drum or disc driven in rotation by a spring mechanism. The drum or disc carries lugs projecting onto the cylindrical surface of the drum or onto one of the faces of the disc. When the lug passes the end of the tongue, the cam-shaped end of the tongue is moved or raised and then abruptly dropped, which causes vibrations of each activated tongue.
Comb 2A connecting one of the ends of tongues 2C is provided with a hole 2B for supporting the comb on a support 3 or a base by a support jaw 4. Preferably, comb 2A includes at least two holes 2B for the securing thereof to support 3. This jaw 4 is supported on the comb and is secured by at least one tightening element 5 traversing jaw 4 and one of holes 2B of comb 2A. Preferably, at least two tightening elements 5 respectively passing through the two holes 2B of the comb are arranged to secure the comb to the support, clamped between one portion of jaw 4 and a surface of support 3. The tightening elements 5 may advantageously be screws, with the screw head pressing against a top surface of jaw 4 and the shaft passing through a corresponding aperture in the jaw before being screwed into an internal thread of support 3. The further each tightening screw is screwed into the internal thread of the support, the greater the clamping force applied to an end portion of tongues 2C of the pin-barrel, ensuring improved hold.
Support jaw 4 is formed by a rigid thick plate forming a clamp, which covers the comb and an end portion of the tongues connected to the comb. By securing jaw 4 to the support by sandwiching the comb and an end portion of the tongues, it is possible to adapt the active length of the tongues, which is one of the vibration parameters of each tongue of the pin-barrel.
To achieve this in an advantageous manner, it is possible to adjust the frequency range by reducing the free length of the vibrating tongue or tongues 2C by the localised clamping of said tongue between support jaw 4 and a local counter-support 7 as shown in
The new active region of the tongue or tongues is that located between the clamping at the first clamping points of
With this localised clamping of the tongue or tongues of the pin-barrel, there is therefore created a new vibration node in clamping region P as shown in
To achieve this, support jaw 4 and, at least indirectly, support 3 are configured to form a local clamping region P and the hole or holes 2B of the comb are elongated in the direction of the tongues to allow each tongue to move relative to local clamping region P. By pressing on each tongue 2C at a distance from comb 2A, a new vibrating tongue length will be defined, which is shorter than the original length, which was the distance between the comb and the free end of each tongue of the pin-barrel.
Support jaw 4 and counter-support 7 will thus lock comb 2A and an end portion of tongue or tongues 2C onto support 3. This end portion of the tongues, which is situated between the local clamping region and the comb, will therefore be immobilised and thus will no longer vibrate. The active length of the tongue or tongues therefore extends between the local clamping region and the free end of said tongues.
In order to adjust the active length of the tongue or tongues of the pin-barrel, the comb connected to the tongues is moved, particularly relative to support 3, to support jaw 4, and to counter-support 7, which forms fixed points. This movement of the pin-barrel is possible, because the hole or holes 2B of comb 2A are elongated along the longitudinal axis of the tongues. The further backwards the comb is moved, the shorter the active length of each tongue will be after the jaw has been secured to the support by the tightening screws. It is thus possible to modify the frequency or range of frequencies without removing or adding material to the tongue or tongues of the pin-barrel.
Support 3 and the means of securing the tongue or tongues, such as support jaw 4, are considered to be means having a fixed position. It is thus by moving the comb and thereby the tongue or tongues, that the sound producing device is adjusted.
Several embodiments of the sound producing device provided with means of adjusting the frequency range of the musical pin-barrel will be described below.
In a first embodiment of
To improve tightening, the back edge of support 3 and the back edge of jaw 4 also have a rib 3B, 4B respectively, which are positioned facing each other. Thus, comb 2A and the tongue or tongues 2C are in contact with the support and the jaw only on the ribs, so that the force exerted by the screw on jaw 4 is converted into localised clamping pressure on the tongue and on the comb. This pressure is concentrated on the clamping regions.
In a second embodiment shown in
Each jaw 4, 8 includes two plates 10A, 10B, 11A and 11B, which are situated in two substantially parallel planes and are joined by a cross-shaped member 12A, 12B, one of which is a first loop 12A and the other is a second inclined loop 12B. This second inclined loop 12B is inserted into the first loop 12A. The pin-barrel tongues pass between the first and second loops. The plates have ribs facing each other to form a front clamping region P and a back clamping region R. Front clamping region P is arranged to clamp an end portion of the pin-barrel tongues, in order to adjust the frequency range of said pin-barrel. Clamping region P may be defined as the first clamping points, whereas the back clamping region R on the comb may be defined as the second clamping points.
Clamping region R is formed by one of the pairs of ribs 4B, 8B, which are positioned between the back and the intersection of the parts, the other pair 4A, 8A of ribs of clamping region P are located after the cross-shaped members as far as possible therefrom. It may be assumed that ribs 4B, 8B, which are the closest to tightening screws 5 and thus behind the cross-shaped members, act as a pivot line.
One of the two arms of the scissors 10a is supported on support 3 and has a jaw 10B, which is above the tongues of pin-barrel 2, whereas the other arm is above the comb and its jaw is under the tongues.
In the first embodiment of
The lever effect obtained is greater or lesser depending on the position of the pairs of ribs 4A, 8A and 4B, 8B in relation to tightening screws 5 and to the position of the axis of rotation of the pair of scissors. According to this solution, the axis of rotation is formed by the pair of ribs 4B, 8B, located beyond the region where jaws 4, 8 cross.
A third embodiment of the sound producing device is shown in
For forming the pivot line, there are several possibilities. More specifically, on its two lateral sides towards the front, the second jaw 8, which forms a counter-support, carries hooks 20 open towards the back of the jaw. Two lugs 21 of the front edge of first jaw 4 are inserted into these hooks 20 to form the pivot. The two jaws 4 and 8 are wider than the set of vibrating tongues of the pin-barrel. Further, the assembly of the pivots leaves an aperture open for the passage of the tongues.
A fourth embodiment of the sound producing device is shown in
The means of securing cross-piece 8 to jaw 4 are able to move the cross-piece towards jaw 4 to clamp an end portion of the tongues. The principle of these securing means is thus to clamp the tongues at a distance from the comb so as to artificially elongate the comb and to reduce the free length of the tongues. It is thereby possible to modify the resonant frequency of each free tongue.
From the description that has just been given, those skilled in the art can devise several variants of the sound producing device provided with means of adjusting the frequency range of the musical pin-barrel without departing from the scope of the invention defined by the claims. It is possible to obtain selective clamping on certain tongues of the pin-barrel and not all the tongues of the pin-barrel to partially modify the frequency range of the musical pin-barrel. Two distinct means of adjusting the frequency range of the pin-barrel tongues may be provided, fixed, for example, on the same support.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13172119.3 | Jun 2013 | EP | regional |
