A method for frequency tuning of a set of plates for a table, and a table including the set of tuned plates.

Abstract

This invention relates to a method for frequency tuning of a set of plates of a watch, and to a watch including the set of tuned plates. The invention relates to a method for frequency tuning of a set of plates (4, 5) of a watch (1). These plates are arranged one on top of another to form a dial, and a space is defined between these plates. A mechanical shock is applied to the set of plates, and the vibration frequency of each plate is checked. If the vibration frequency of at least one plate differs from that of another plate, the vibration frequency of at least one of the plates is matched so that the same vibration frequency is obtained for each plate, thereby tuning the plates at least according to a first inherent vibration mode to avoid any contact between the plates due to any mechanical shock.

Description

Technical Field

[0001] This invention relates to a method for frequency tuning of a set of plates of a watch. These plates are preferably the dial plates of the watch. These plates can also be used as acoustic radiating membranes for chiming watches or musical watches.

[0002] The present invention also relates to a table comprising the assembly of boards tuned according to a tuning method. Background Technology

[0003] In the case of watches with overlapping plates (serving as the dial), extreme care must be taken to avoid any mechanical impact that could cause the plates to come into contact, potentially leading to breakage or fracture of one of the plates made of fragile materials. Generally, these plates are spaced far enough apart to prevent them from contacting each other due to mechanical impact. However, when mounted in a conventional watch case, spacing the plates far enough apart is unsuitable because it results in a significant loss of space to accommodate the various components.

[0004] A striking mechanism may also be present in the watch to produce sound (tone) or music. For this purpose, the gong of a striking watch or the clavier of a musical watch is usually housed within the watch case. The vibration of the gong or clavier tongue is transmitted to various external components. These external components may be, for example, the carrure, the bezel, the crystal, and the case back, or even a dial with a commemorative plate to give the watch an aesthetically pleasing appearance.

[0005] In the case of musical or chiming clocks, the acoustic performance is poor due to the complex vibration-sound conversion of external components. To improve and enhance the sound level perceived by the user of a chiming or musical clock, the materials, geometry, and limiting conditions of the external components must be considered. The construction of these external components also depends on the clock's aesthetics and operational constraints, which may limit the possibility of adaptive modifications.

[0006] The frequency composition of the sound from a striking or musical watch must be rich in the frequency range of 0.5 kHz to 5 kHz or even 10 kHz. Conventional external components do not provide effective radiation in this frequency band. Therefore, to further improve the vibro-acoustic performance of the striking mechanism, one or more diaphragms are disposed within the watch case, for example, one diaphragm on top of another, with space between them. The diaphragms are sized and constructed such that one or more tones generated within the watch case are effectively radiated. The frequencies of the generated tones must be close to the inherent vibrational modes of the diaphragms so that they resonate. However, there are usually no regulations governing the frequency tuning of these diaphragms, particularly ensuring that they do not come into contact with each other primarily during mechanical shocks to the watch or during the generation of tones or music.

[0007] Constraints on diaphragm arrangement are generally contrary to mechanical structural rules to ensure sealing and mechanical strength to resist impacts and high external pressures.

[0008] European Patent Application No. 1,795,978 A2 describes a watch that includes a striking mechanism. This striking mechanism comprises two bell-shaped diaphragms, coaxially held within the watch case by a central support rod, with one diaphragm on top of the other. Another diaphragm is also disposed between the two bell-shaped elements and the backplate of the watch case, and is pressurized and attached between the intermediate element and the perforated backplate of the watch case. The acoustic radiation frequency of this diaphragm can be adjusted depending on the radial stress adjustment of the other diaphragm. However, the two additional bell-shaped diaphragms are not arranged to improve the sound level of the sound produced by the striking mechanism, which constitutes a disadvantage. Furthermore, the frequency tuning method does not seek to improve the watch's resistance to mechanical shocks through frequency tuning.

[0009] European Patent Application No. 3,009,894 A1 describes an acoustic radiating diaphragm device for a chiming or musical watch. The device includes a first diaphragm superimposed on a second diaphragm. The peripheral edges of the two diaphragms are used to hold the diaphragms within a watch case. The first acoustic radiating diaphragm is configured to effectively radiate frequencies in a first frequency band, while the second acoustic radiating diaphragm is configured to effectively radiate frequencies in a second frequency band different from the first frequency band. A spacer ring is also disposed between the peripheral edges of the first and second diaphragms to define an acoustic cavity. No frequency tuning of the diaphragms is provided to prevent them from contacting each other due to activation of a reed or tongue, or primarily due to mechanical impact. Summary of the Invention

[0010] Therefore, the object of the present invention is to overcome the shortcomings of the prior art by proposing a method for frequency tuning of a set of plates of a watch (especially the dial forming the watch) (in order to withstand mechanical shocks to the watch), the watch being a chiming watch or a music watch.

[0011] Therefore, the present invention relates to a method for frequency tuning of a set of plates of a meter, the method comprising features of the basic aspects of the method according to the invention.

[0012] In a preferred aspect of the method of the invention, specific steps are defined for a method of frequency tuning of a set of plates of a table.

[0013] One advantage of the method for frequency tuning a set of plates for a watch is that at least two plates forming the dial can be tuned to improve their resistance to mechanical shocks. Preferably, each plate forming the dial can also serve as an acoustic radiating diaphragm for a striking or musical watch. Each plate is frequency-tuned, for example, particularly by controlling a first inherent vibration mode. The two plates, spaced a relatively short, defined distance from each other, are thus tuned so that they do not come into contact with each other due to mechanical shocks to the watch. As a result of the frequency tuning of these plates, one of them is made of a fragile material such as sapphire, and the two plates are able to vibrate in phase so that they do not come into contact with each other during mechanical shocks. It can also be used to improve the acoustic radiation of the tone or music produced by a striking or musical watch.

[0014] Advantageously, the first dial plate is made of metal, while the second dial plate is made of sapphire, a hard, brittle, and fragile material. Within the case, the sapphire plate can be 0.4 mm thick or thinner.

[0015] Advantageously, the sapphire plate can be used as a second dial to provide new aesthetic codes, or in the case of a chiming or musical watch, the sapphire plate can also be used together with the first dial plate as a vibrating and radiating film.

[0016] Therefore, the present invention also relates to a table comprising a set of plates tuned according to a tuning method, the table including features of the basic aspects of a table according to the present invention. Attached Figure Description

[0017] The purpose, advantages, and features of the method for tuning the frequency of a set of plates forming the dial of a watch will become clearer in the following description, particularly with reference to the accompanying drawings, in which:

[0018] - Figure 1 A cross-section of a watch (e.g., a chiming watch or a musical watch) according to the invention is shown, the watch having a set of plates forming a dial, the plates being spaced apart from each other and tuned to improve their ability to withstand mechanical shocks.

[0019] - Figure 2 A cross-section showing a deformation of a first inherent pattern of at least one of the plates forming the dial according to the invention is illustrated.

[0020] - Figure 3a and 3b The diagram shows two graphs of the dial-forming plates before and after frequency tuning according to the invention, showing the plates vibrating due to mechanical impact or during striking or playing music.

[0021] - Figure 4 A digital model for determining the vibration frequency and frequency tuning of the group of plates according to the present invention is shown. Detailed Implementation

[0022] In the following description, all well-known components of a watch (such as a chiming watch or a musical watch) will be described only briefly. Specific mention will be made of methods used to frequency-tune a set of plates for the watch in order to improve its ability to withstand mechanical shocks that may be applied to the watch and the set of plates.

[0023] Figure 1 The diagram schematically illustrates a cross-section of a watch 1 with a set of plates 4 and 5 forming a dial in this embodiment. The watch 1 also includes a case consisting of an intermediate component 2, which is enclosed on the top side by glass 3 and on the bottom side by a back plate 8. A watch movement 7 is located between the back plate 8 and the set of plates 4 and 5 forming the dial. A time-indicating hand 6 is connected to the watch movement 7 and extends from the set of plates 4 and 5 to indicate the time on the dial 5 of the set of plates forming the dial.

[0024] It goes without saying that the plates can be located in other places within the watch case and are not necessarily used as a set of plates forming the dial. For example, it could be two plates spaced apart from each other, thus forming part of the middle part 2 of the watch case, or part of the back plate 8 of the watch case, or located in other places within the watch case.

[0025] The dial-forming plates 4 and 5 comprise: a first dial plate 4, made of, for example, a metal material; and a second plate 5 located above the first dial plate 4, made of a hard, brittle material, such as sapphire or other brittle materials. Preferably, the second plate 5 is substantially transparent, allowing aesthetic inlays or indices to be seen on the bottom surface of the second plate 5 or on the top surface of the first plate 4.

[0026] Two plates 4 and 5 are mounted such that they are spaced apart from each other at a defined distance. For example, a distance of less than or equal to 1 mm can be provided between the two plates 4 and 5. Preferably, the distance separating the plates 4 and 5 can be much less than 1 mm, for example, 0.1 mm, so as not to lose too much space in the case 1. However, the spaced-apart plates 4 and 5 must be constructed such that they do not come into contact with each other during mechanical shock. Therefore, a frequency tuning method is performed so that the vibration frequency can be matched to at least a first inherent vibration mode of the two plates 4 and 5, as discussed in the description below.

[0027] It should be noted that in the event of a mechanical impact, the external components and movement elements constituting Table 1 will experience strong acceleration. Under such acceleration, the plates 4 and 5 forming the dial will deform and may come into contact with adjacent components (e.g., hands 6). In a specific case of the structure of the invention, a sapphire plate 5 may be added, which is spaced apart from the dial plate 4 for aesthetic purposes and may come into contact with the dial plate 4 during a mechanical impact. Depending on the height from which the external components fall, the first dial plate 4 in this group may come into contact with the second sapphire plate 5, which may cause the second sapphire plate 5 to break, as it is a brittle material. To ensure the watch's ability to withstand mechanical impacts, including the plates 4 and 5, all components of the watch must be correctly sized. However, the aesthetics of the watch impose certain constraints that are sometimes incompatible with the structure that ensures good mechanical strength in the event of a mechanical impact.

[0028] Because sapphire is a fragile material, it is best to avoid any direct impact on this type of material. Table 1, with its set of plates 4 and 5, presents several possibilities for preventing any contact between the two plates 4 and 5. These possibilities are:

[0029] - Increase the rigidity of the first dial plate 4 to prevent its deformation. The first dial plate 4 is an aesthetic element, which is decorated and is usually made of expensive and very dense materials. Therefore, the first dial plate 4 must have a considerable thickness to prevent its deformation. However, this will increase the overall thickness of the external components, which is undesirable.

[0030] - Increase the gap between the first dial plate 4 and the second sapphire plate 5. The first dial plate 4 may deform due to mechanical impact and fail to contact the other second plate 5, which will also vibrate. The increased distance between the first dial plate 4 and the second sapphire plate 5 directly affects the thickness of the external components and the aesthetics of the watch. The readability of the dial will also be compromised.

[0031] - The natural frequency of the first dial plate 4 and the natural frequency of the second sapphire plate 5 are tuned so that the first dial plate 4 and the second sapphire plate 5 vibrate in phase and do not collide with each other, without increasing the gap between the two components fixed by the design.

[0032] It should be noted that this invention is primarily based on the last item in the above list. Therefore, a digital model has been developed to predict the dynamics of the first dial plate 4 and the second sapphire plate 5 under impact from an external component. The first dial plate 4 and the second sapphire plate 5 are represented by a weight-spring-shock absorber system, as described below. Figure 4 As shown (modeling the deformation of the first inherent mode of the first dial plate 4 and the deformation of the first inherent mode of the second sapphire plate 5). The two weights are separated from each other by the clearance imposed by this structure. Figure 4 ).

[0033] Figure 3a and 3b The graphs show the method of frequency tuning for the boards in the group before and after the frequency tuning operation. Figure 3a The state before frequency tuning is shown, while Figure 3b The state after frequency tuning is shown. The vibration of the first plate is represented by a solid line, while the vibration of the second plate is represented by a dashed line.

[0034] In the frequency tuning method, after a mechanical impact is generated by a testing device, the vibration of each plate 4, 5 is examined. One or more plates 4, 5 are placed on the testing device such that they are stacked on top of each other, with a defined space between the plates. Based on the vibration of each plate, it can be determined whether one plate is in contact with another plate. Figure 3a The situation is illustrated. The mechanical impact occurs at time T = 0. After the mechanical impact, each plate 4, 5 vibrates or oscillates at a frequency depending on the size, shape, and material of the plate. It can be seen that the first metal plate oscillates at a frequency slightly higher than 1 kHz, while the second sapphire plate oscillates at a frequency higher than the first plate and slightly higher than, for example, 2 kHz, where the vibration of either plate decays over time. It can be seen that due to these differences in vibration, the second plate is in direct contact with the first plate ( Figure 3a (The deeper part), and then through single-point contact indicated by the point, this can create a fracture point on the second plate made of fragile material. After frequency analysis of the vibration of each plate by the testing device, a correction means can be determined for each plate, or at least one of the plates, so that the two vibrating plates vibrate in phase. In this case, as Figure 3b As shown, once these plates vibrate at substantially equal frequencies, they are therefore in phase according to at least the inherent mode of the first vibration, and will not come into contact with each other.

[0035] It should be remembered that, Figure 3a Following this step of the method shown, when the plates are in contact with each other, at least one of the plates must be constructed. At least one of the plates must be constructed or adapted to vibrate at the frequency of at least the first inherent mode of vibration of the other plate. Therefore, after the mechanical impact on plates 4 and 5, the two plates (whose vibration frequencies are matched, in particular, according to at least the first inherent mode of vibration) will no longer be in contact with each other, which allows the second plate 5, made of a fragile material, to be protected, such as... Figure 3b As shown in the image.

[0036] To match the vibration frequencies of these plates, actions can be performed on at least one of the plates (by adding a weight to at least one of the plates at a predetermined location, such as its center) to give it the same phase deformation as the other vibrating plate. The added weight can be hammered into the center of the second plate. Alternatively, multiple small inertial blocks can be added at different locations on the plates.

[0037] The stiffness or limiting conditions of the plates, or at least one of them, can also be altered to prevent any contact between the plates due to mechanical impact. It goes without saying that, instead of adding weight or changing stiffness, action can be taken on at least one of the plates: using a laser to locally etch or remove material to change the vibration frequency until a vibration frequency of at least a first vibration mode equal for both plates is obtained. This allows the two plates to be spaced a short, defined distance, such as 0.1 mm, while ensuring that the two plates do not contact each other due to mechanical impact.

[0038] It should be noted that for the construction of either of the two plates 4 and 5, the developed digital model implemented in the test apparatus can be used. Figure 4 Furthermore, the digital model is capable of determining the matching means for frequency tuning of one of the plates. It goes without saying that several successive steps of examining the vibration frequencies of each plate can be considered to progressively manage and construct at least one of the plates, thereby obtaining two plates vibrating in phase at the end of the method.

[0039] The inherent frequencies of the dial and sapphire plate must be characterized (because they depend on the manufacturing tolerances of these components) in order to adjust the weight added to the center of the sapphire plate according to the specific circumstances.

[0040] The frequency testing apparatus used for frequency tuning in this method will not be described in detail, as the components of the apparatus are already known in other fields.

[0041] As mentioned above, the plates that form the dial can also be used as acoustic radiation membranes for chiming or musical watches, and for chiming or musical watches, the goal is to tune the plates or membranes so that they vibrate in phase without contacting each other.

[0042] As an explanation, Figure 2 Only a cross-section of the deformation of at least the first inherent mode of the first dial plate 4 is shown. It goes without saying that deformations of the first or higher inherent modes of the group of plates 4 and 5 could also be shown.

[0043] Based on the foregoing, those skilled in the art can conceive of several alternative embodiments of the method for frequency tuning of a set of plates of a meter without departing from the scope of the invention as defined by the claims.

Claims

1. A method for frequency tuning of a set of plates (4, 5) of table (1), said plates being arranged such that one is on top of the other and a space is defined between said plates, wherein, A mechanical impact is applied to the assembly of plates, and the vibration frequency of each plate is checked. The assembly of plates forms the dial of the table (1). The assembly of plates has at least a first plate (4) and a second plate (5), the second plate (5) being located on top of the first plate (4) and spaced apart from the first plate (4). The assembly is characterized in that if the vibration frequency of at least one of the plates is different from that of the other plate, a vibration frequency matching operation is performed on at least one of the plates to obtain the same vibration frequency for each plate, thereby tuning the plates at least according to a first vibration inherent mode to avoid any contact between the plates due to any mechanical impact.

2. The method for frequency tuning of a set of plates (4, 5) of table (1) according to claim 1, wherein, The second plate is made of a fragile, brittle material, characterized in that the set of plates (4, 5) forming the dial are tested in a testing device that applies a mechanical impact to the set of plates (4, 5), wherein the vibration frequency of each plate is determined, and wherein a vibration frequency matching operation is performed on one of the plates to tune the two plates to the same vibration frequency so that the two plates are in phase, thereby avoiding any contact between the plates due to any future mechanical impact.

3. A method for frequency tuning of a set of plates (4, 5) in Table (1) according to any one of the preceding claims, wherein, The first plate (4) and the second plate (5) are spaced apart. The distance is 0.1 mm or less, characterized in that the vibration frequency of the second plate (5) is at least matched with the first vibration inherent mode of the first plate (4), which is made of a metallic material.

4. The method for frequency tuning of a set of plates (4, 5) of table (1) according to claim 3, characterized in that, Multiple frequency determination and matching operations are performed until the same vibration frequency relative to at least one first vibrational inherent mode is obtained, the at least one first vibrational inherent mode being caused by a mechanical impact on the plate.

5. The method for frequency tuning of a set of plates (4, 5) of table (1) according to any one of claims 1 to 2, characterized in that, In order to match the vibration frequency of one of the plates to be in phase with the vibration frequency of the other plate, a weight is added to one of the plates, the vibration frequency of which is greater than that of the other plate.

6. The method for frequency tuning of a set of plates (4, 5) of table (1) according to claim 5, characterized in that, The weight was knocked into the center of the second plate.

7. The method for frequency tuning of a set of plates (4, 5) of table (1) according to any one of claims 1 to 2, characterized in that, In order to match the vibration frequency of one of the plates to make it in phase with the vibration frequency of the other plate, the stiffness or limit condition of the plate group or at least one of the plates is changed.

8. The method for frequency tuning of a set of plates (4, 5) of table (1) according to any one of claims 1 to 2, characterized in that, To match the vibration frequency of one of the plates to make it in phase with the vibration frequency of the other plate, a laser is used to locally etch or remove material so as to obtain the same vibration frequency of the two plates with respect to at least a first vibrational intrinsic mode.

9. The method for frequency tuning of a set of plates (4, 5) of table (1) according to any one of claims 1 to 2, characterized in that, The digital model developed in the test setup was used to frequency tune the board (4, 5), with frequency matching performed for each test.

10. The method for frequency tuning of a set of plates (4, 5) of table (1) according to any one of claims 1 to 2, characterized in that, The two plates (4, 5) forming the dial of the clock are frequency matched as the acoustic radiation diaphragm of the clock or music clock.

11. The method for frequency tuning of a set of plates (4, 5) of table (1) according to claim 2, wherein, The second plate is made of sapphire.

12. A table (1) comprising a set of plates (4, 5) forming the dial of the table, and tuned based on a method for frequency tuning of the set of plates (4, 5) of the table (1) according to any one of the preceding claims.

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