Watches with vibration amplifiers

Abstract

The present invention relates to a timepiece (1) comprising a case, a movement and a vibration generator housed within the case adapted to generate at least one sound, a device (16) for amplifying the vibrations generated by the vibration generator, and a membrane adapted to receive the amplified vibrations and generate sound from the inside to the outside of the timepiece, the vibration amplifier device (16) being pivotally mounted on a support (22) in a pivot plane not parallel to the plane of the membrane and comprising a lever (20) adapted to be actuated by a transmission member which cooperates with the vibration generator to transmit vibrations to the lever (20), the lever (20) being translationally fixed to the membrane at least in the pivot plane so that a displacement of the transmission member, generated by vibrations of the transmission member connected to the vibration generator and transmitted to the membrane via the lever actuated by the transmission member, generates an amplified displacement of the membrane so as to generate an amplified sound.

Description

[Technical field]

[0001] The present invention relates to a timepiece comprising a case having a middle part, a back cover and a bezel, a movement and a vibration generator housed within said case adapted to generate at least one sound, a device for amplifying the vibrations generated by said vibration generator, and a membrane adapted to receive the amplified vibrations and generate a sound from the inside towards the outside of the timepiece. [Background technology]

[0002] Such a timepiece is, for example, a watch with a striking mechanism (minute repeater, grand sonnerie, petite sonnerie, alarm, etc.) in which the vibration generator is, for example, a gong arranged to be struck by a hammer when the striking is initiated in order to generate vibrations for the purpose of generating sound. The gong conventionally takes the form of a strip spring wound around the movement. The gong is integrally attached to the watch frame (bottom plate and bridge assembly) via a heel or a gong holder in order to transmit the vibrations of the gong to the whole watch (frame, movement, external parts). The vibrations of the gong are thus transmitted with maximum intensity to the wearer of the watch.

[0003] Since sound transmission is obtained by putting the entire watch into vibration, it has been proposed to strengthen the various elements of the watch in order to help them vibrate and thus improve said sound transmission.

[0004] Although this solution gives satisfactory results in terms of sound transmission quality, it gives rise to other problems, such as the appearance of undesirable sounds, because the greater the sound intensity, the more the movement vibrates, and due to the vibrations, the more noise the various movement components generate. These vibrations combine to produce undesirable noises.

[0005] One solution to amplifying the sound is to increase the force with which the hammer strikes the gong, which allows for an increased volume level but degrades the sound quality with unwanted noise.

[0006] The timepiece described in EP 3525045 A1 proposes to solve this problem by using a sound transmission bridge attached to the bottom plate or, more generally, to a frame element, said transmission bridge also being in contact with a membrane fixed to the middle part of the watch case. Thus, when the gong itself, which is attached integrally to the frame, vibrates, the sound transmission bridge also vibrates in the same way and transmits this same vibration to the membrane. Due to its rigidity and its surface area, the transmission bridge contributes to a significant air displacement, which improves the intensity and quality of the sound. Moreover, the transmission bridge can be integrated with frame elements other than the bottom plate, and therefore may transmit to the membrane vibrations originating from other frame elements around other movement components.

[0007] However, unwanted noise still occurs due to residual vibrations of the various movement components caused by frame vibration. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] European Patent Application Publication No. 3525045 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to overcome these drawbacks by proposing a timepiece comprising a vibration generating device adapted to generate at least one sound, and a device for amplifying these vibrations, enabling said generated sound to be greatly amplified.

[0010] A further object of the invention is to allow amplification of the generated sound without undesirable noise, or at least with suppression of said undesirable noise. [Means for solving the problem]

[0011] To this end, the invention relates to a timepiece comprising a case having a middle part, a back cover and a bezel, a movement and a vibration generator housed within said case adapted to generate at least one sound, a device for amplifying the vibrations generated by said vibration generator, and a membrane adapted to receive said amplified vibrations and generate a sound from the inside towards the outside of the timepiece.

[0012] According to the invention, the vibration amplification device comprises a lever pivotally mounted on a support in a pivot plane non-parallel to the plane of the membrane and configured to be actuated by a transmission member which cooperates with a vibration generator to transmit vibrations to the lever, and in addition, said lever is translationally integral with the membrane at least in the pivot plane, such that the movement of the transmission member generated by vibrations of said transmission member connected to the vibration generator and transmitted to the membrane via the lever actuated by said transmission member generates an amplified movement of said membrane so as to generate an amplified sound.

[0013] Thus, with the amplification device used in the present invention, the generated vibrations are collected by a lever configured to mechanically amplify said vibrations before transmitting them to the membrane, generating a first sound amplification.

[0014] Preferably, the vibration amplification device is separated from the movement so that the vibrations are not transmitted to the movement and / or frame elements (bottom plate and bridges). Furthermore, the membrane is preferably and advantageously arranged outside the movement, in particular in the bezel or back of the watch, so that the membrane itself is separated from the movement so that none of the vibrations transmitted to the membrane are dissipated in the movement. The watch according to the invention therefore generates little or no undesirable noises related to the vibrations of the movement elements and / or frame elements. Since all vibrations are directed to the membrane without being transmitted to one of the movement elements and / or frame elements, in the case of the striking mechanism, it is possible to modify the striking force on the gong without affecting the vibrations of the movement elements and / or frame elements.

[0015] Advantageously, a compression chamber is provided that is adapted to amplify the sound generated by the movement of the membrane before it emerges to the outside.

[0016] This allows a second amplification of the sound to occur.

[0017] Thus, the watch according to the invention is capable of producing a highly amplified sound with little or no unwanted noise. [Brief description of the drawings]

[0018] Other characteristics and advantages of the invention will become apparent from reading the following detailed description of various embodiments of the invention, given by way of non-limiting example, the description being made with reference to the accompanying drawings, in which:

[0019] [Figure 1] FIG. 2 is a view of the back cover of the watch according to the first embodiment of the present invention. [Diagram 2] FIG. 2 is a partial cross-sectional view of the back cover side of the watch of FIG. 1. [Diagram 3] FIG. 11 is a perspective view of the back cover of a timepiece according to a second embodiment of the present invention. [Figure 4]FIG. 2 is a diagram of a membrane and a vibration amplifier device according to a first embodiment of the invention. [Diagram 5] FIG. 2 is a cross-sectional view of the membrane and compression chamber. [Figure 6] FIG. 13 is a diagram of a means for adjusting the volume of the sound generated by the membrane. [Figure 7] FIG. 4 is a partial cross-sectional view showing the volume control means in a closed position. [Figure 8] FIG. 4 is a partial cross-sectional view showing the volume control means in an open position. [Figure 9] FIG. 2 is a perspective view of a timepiece according to the invention, showing the closure of the opening of the compression chamber outside the sound generation period. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present invention relates to a timepiece comprising a case having a middle part, a back cover and a bezel, a movement and a vibration generator housed within said case adapted to generate at least one sound, a device for amplifying the vibrations generated by said vibration generator, and a membrane adapted to receive the amplified vibrations and generate a sound from the inside towards the outside of the timepiece. According to the invention, the vibration amplification device comprises a lever pivotally mounted on the support in a pivot plane non-parallel to the plane of the membrane and configured to be actuated by a transmission member which cooperates with the vibration generator to transmit vibrations to the lever, the lever being additionally integral with the membrane translationally at least in the pivot plane, the actuation point of the lever, the pivot point of the lever and the connection point of the lever with the membrane being arranged such that the movement of the transmission member generated by vibration of the transmission member connected to the vibration generator is transmitted to the membrane via the lever actuated by the transmission member, amplified by the lever arm effect of the lever.

[0021] The vibration generating device may be a striking gong adapted to be struck by the striking hammer, said striking gong being integral with a transmission member, said transmission member being integral with the lever.

[0022] In another variation, the vibration generator may be a rotating disk with engraved grooves configured to generate sound, and the transmission member is a stylus integral with the lever and configured to follow the grooves on the disk.

[0023] In another variant, the vibration generating device may be a music box with a vibrating blade fixed by a stud, the transmission member being integral with said stud and lever.

[0024] In the following description, the vibration generating device is a striking gong struck by a striking hammer and the watch is equipped with a striking mechanism (alarm) for indicating the time (minute repeater, grand sonnerie, petite sonnerie) or for striking at a given moment of time. The watch is preferably a watch, more preferably a wristwatch adapted to be worn on the wrist of a user.

[0025] Unless otherwise stated, the rest of the description of the invention, and in particular the vibration amplifier device, applies equally to watches equipped with a rotating disk read by hands, or a music box.

[0026] With reference to Figures 1, 2 and 9, the watch 1 comprises a case 2 having an intermediate part 3, a back cover 4, a bezel 5 and a first crystal 6. The back cover 4 is annular and its central opening is closed by a second crystal 7, the function of which will be described below. The bezel and the intermediate part may be two distinct parts or may form a single monoblock piece. Similarly, the back cover and the intermediate part may be two distinct parts or may form a single monoblock piece.

[0027] In the following description, the vibration amplifier and the membrane are configured to generate sound through the back of the watch, and more particularly through the second crystal 7. Naturally, the vibration amplifier and the membrane may also be configured in a similar but reverse manner to generate sound from the dial side of the watch, and more particularly through the first crystal 6.

[0028] 1, 2 and 4, the watch 1 also comprises a movement (not shown) and a striking mechanism 9 constituting a vibration generating device adapted to generate at least one sound. The movement and the striking mechanism 9 are housed in the middle part 3 of the case 2 and are attached to a frame 10 (bottom plate and bridge). The striking mechanism 9 comprises a hammer 12 arranged in known manner to strike a striking gong 14, in this case a wire or strip spring gong wound around the movement.

[0029] In order to amplify the sound produced by the gong 14, in addition to a device 16 for amplifying the vibrations generated by the gong 14, a membrane 18 is provided which is adapted to receive said amplified vibrations and generate sound from the inside to the outside of the watch. In this case, the sound is transmitted from the back cover side, and the membrane 18 is attached to said back cover 4 parallel to said back cover 4, between the movement and the second crystal 7. When transmitting sound from the dial side, the membrane is attached to the inside of said bezel 5 parallel to said bezel 5, between the movement and the first crystal 6.

[0030] According to the invention, the vibration amplifier device 16 comprises a lever 20 connected to a support 22 by a joint along a single axis of rotation, such that the lever 20 is tiltably or pivotably mounted to the support 22 about the axis of rotation in a pivot plane non-parallel to the plane of the membrane 18.

[0031] More preferably, the lever 20 is pivotally mounted on its support 22 so as to tilt in a pivot plane perpendicular to the plane defined by the membrane 18 .

[0032] According to a first embodiment, shown in figures 1, 2 and 4, the lever 20 is pivotally attached to the support 22 via a flexible ball joint 24. The flexible ball joint makes it possible to change the direction of vibration if necessary. In particular, in the case of a striking gong, the support 22 tends to vibrate radially, in the direction in which the hammer strikes the hour. Preferably, the position of the flexible ball joint 24 of the lever 20 makes it possible to change the direction of the radial vibration of the gong by 90° and convert it into a movement perpendicular to the plane of the membrane 18 by pivoting said lever 20.

[0033] According to a second embodiment, shown in figure 3, the lever 20 is pivotally mounted to the support 22 by means of a pin 26 which is attached laterally to the support 22 and which constitutes the pivot axis of the lever 20. A spring 27 acts on the support 22.

[0034] The lever 20 is configured to be actuated by a transmission member 28 which cooperates with the gong 14 to transmit vibrations to the lever 20. The transmission member 28 is preferably integral with the lever 20. The transmission member 28 consists, for example, of a heel or a gong holder which is integral with the lever 20, the gong 14 being attached to the lever 20, for example by embedding, screwing or brazing. For this purpose, the transmission member 28 comprises an orifice 30 into which the gong 14 is inserted. The gong 14 is thus integral with the lever 20 and is not fixed to the frame of the watch via the heel. The transmission member 28 may be attached to the lever 20 or may be integral with the lever 20. If the lever 20 is made of steel, the gong 14, the transmission member 28 and the lever 20 may be made in a single piece.

[0035] The lever 20 is also integral with said membrane 18 translationally at least in the pivot plane of the lever, in order to be able to move said membrane 18 in the pivot plane of the lever 20 when the lever 20 is tilted. It is the linear movement of the membrane 18 moved by the lever 20 that produces the sound.

[0036] More specifically, the lever 20 is pivotally mounted on the support 22 and comprises a first end 20a integral with the transmission member 28 and a second end 20b translationally integral with the membrane 18, at least in the pivot plane of said lever 20.

[0037] Preferably, in the case of striking mechanisms in which the transmission member 28 is fixed relative to the gong 14, the lever 20 is translationally fixed and fixedly connected to the membrane 18, i.e. the lever 20 is rotationally and translationally integral with the membrane 18. The lever 20 can be fixed to the membrane 18, for example, by means of a screw 32 threaded into a hole 34 in the membrane 18 and a hole 36 in the lever 20, or by gluing, welding etc.

[0038] In the case of a stylus-read disk, the lever and stylus are configured to allow translational movement of the lever and stylus in the plane of the membrane, and when the lever is tilted, the lever remains translationally integral in the pivot plane of the membrane 18 so as to allow the membrane 18 to move in the pivot plane of the lever.

[0039] The point of actuation of lever 20 by transmission member 28, the pivot point of lever 20 and the connection point of lever 20 with membrane 18 are arranged so that movement of transmission member 28, caused by vibration of said transmission member 28 connected to gong 14, transmitted to membrane 18 via lever 20 actuated by said transmission member 28, produces an amplified movement of said membrane 18 by a mechanical lever arm effect, thereby producing an amplified sound.

[0040] Preferably, the flexible ball joint 24 is located at the centre of mass of the gong / lever / membrane assembly.

[0041] Preferably, the connection point between the lever 20 and the membrane 18 is located at a distance from the center of the membrane 18 that is less than 40%, preferably less than 20%, of the width of the membrane 18. More preferably, the connection point between the lever 20 and the membrane 18 is located at the center of the membrane 18 to maximize the lever arm effect.

[0042] In another variation, the attachment points can be located on the periphery of the membrane, taking advantage of the elasticity of the fixed points and the torsion of the membrane.

[0043] Advantageously, the vibration amplifier, and more particularly the support 22 of the lever 20, is separated from the movement, from the striking mechanism 9 and from the frame 10. For this purpose, the support 22 of the lever 20 may be attached to an external part, more particularly to the bezel 5, if the sound is transmitted from the dial side, or to the back cover 4, if the sound is transmitted via the back cover. The striking gong 14 is embedded in a transmission member 28 integral with the lever 20, so that said gong 14 is not fixed to the frame via a heel, as is conventional, but appears to float around the movement.

[0044] The support 22 of the lever 20 may also be attached to the movement or even to the intermediate part 3, provided via a separating element 35, such as a polymer, in order to ensure separation of the support 22 from the movement, the intermediate part and the frame.

[0045] When the support 22 of the lever 20 is attached to one of the elements of the case (bezel 5, middle part 3, back cover 4), it is also possible to separate the movement from the rest of the watch by placing a separation device on the movement between the movement and said element of the case that supports the support 22 of the lever 20. Such a separation device may for example be a brass ring associated with a flat gasket, or a separation ring of carbon-filled polyetheretherketone (PEEK). For example, to separate the movement, said element of the case may be flanged to a PEEK separation ring that is itself screwed into the case middle part.

[0046] When the support 22 of the lever 20 is attached to the bezel 5 or to the back cover 4, said bezel 5 or said back cover 4 may be assembled directly to the intermediate part 3 as is conventional. However, to ensure that undesired vibrations do not reach the intermediate part 3, and thus the movement, said bezel 5 or said back cover 4 is assembled to the intermediate part 3 via a separating element, such as a polymer.

[0047] The membrane 18 is attached to the back cover 4 if the sound is transmitted through the back cover, or to the bezel 5 if the sound is transmitted from the dial side. The membrane 18 is therefore also separated from the movement and the striking mechanism 9.

[0048] As a result, the vibration amplifier and the membrane are isolated from the movement and the frame in such a way that all vibrations of the gong picked up by the lever 20 are directed and transmitted to the membrane 18 without being transmitted to the movement, frame and intermediate parts.

[0049] The lever 20 is preferably made from a very light and very stiff material, for example, the lever 20 may be made from steel, titanium, aluminum, magnesium, composites, carbon, glass, sapphire and ceramics.

[0050] The membrane 18 must be able to vibrate freely. It is preferably made of a very light and rigid material in order to have a large dynamic response and not deform when in motion. The membrane 18 is preferably made of a transparent material. For example, the membrane 18 may be made in the form of a plate of sapphire, mineral glass, Plexiglas®, etc. The membrane 18 may thus be constituted by a third, internal glass placed under the second glass 7 (or, where appropriate, the first glass 6). The membrane 18 may also be made of a composite material of safety glass type, cellulose, or composite glass. Naturally, the membrane 18 may also be made of a material that is not completely transparent, such as a translucent or opaque material, such as metallic glass, titanium, silicon, ceramic, carbon fiber composite, cellulose or Kevlar.

[0051] The membrane 18 should be as stiff and light as possible, and to this end, the thickness of the membrane is less than 1 mm, preferably less than 0.5 mm, and more preferably less than 0.3 mm.

[0052] More specifically, referring to Figure 5, the membrane 18 is preferably mounted on a suspension to allow it to vibrate freely whilst ensuring tightness. The suspension may be provided between said membrane 18 and the back cover 4 (or bezel 5, as appropriate) by a moulded gasket placed around the membrane 18, or by an O-ring gasket placed around the periphery of both sides of the membrane 18. It is also possible to texture the membrane 18 to improve its flexibility, for example by grooves 38 on its periphery. It is also possible to exploit the thickness of the membrane 18.

[0053] Advantageously, the timepiece further comprises a compression chamber 40 configured to amplify the sound generated by the movement of the membrane, already amplified in the first place, before it emerges to the outside.

[0054] The compression chamber 40 is closed by a wall arranged downstream of the membrane 18 and having at least one opening 42 directed towards the outside of the watch. The dimensions of the opening 42 are selected in relation to the surface area of ​​the membrane 18 as a function of the desired sound amplification.

[0055] Preferably, when the membrane 18 is arranged on the back cover 4, said wall is constituted by a second glass 7. Said second glass 7 must be strong and scratchproof. The second glass 7 is preferably made of sapphire.

[0056] A wall placed downstream of the membrane 18 allows a volume of air to be generated in the compression chamber 40. This air is compressed by the movement of the membrane 18. The ratio of the surface area of ​​the moving membrane 18, which defines the volume of air, to the size of the opening allows a second amplification of the sound.

[0057] The opening 42 may take various forms, such as a hole in the wall, in this case the center of the second glass 7, several transverse holes, a number of micro-holes, etc. The shape of the outlet opening may be conical in order to further amplify the sound. Advantageously, the opening 42 may take the form of one or more longitudinal grooves, extending around the intermediate part, parallel to the movement plane, and obtained, for example, by leaving a space between the back cover 4 and the intermediate part 3, when the membrane 18 is arranged on the back cover 4, as shown in FIG. 9. Such a transverse opening 42 advantageously makes it possible to redirect the sound generated by the membrane 18 towards the arm of the watch wearer, giving said wearer a sensation of further amplified sound.

[0058] With reference to Figures 6 to 8, the timepiece advantageously comprises adjustable closure means 44 of the opening 42 of the compression chamber 40, which are configured to allow adjusting the volume of the sound generated by the membrane 18. These closure means 44 are configured to be movable between a closed position in which the opening 42 is completely closed and an open position in which the opening 42 is at its maximum, the intermediate positions allowing a greater or lesser obstruction of the opening 42 in order to adjust the volume. For example, in the case where the opening 42 is a lateral opening, the closure means 44 may comprise a rotating element, such as a ring, rotatably attached to the back cover 4 and configured to rotate between a closed position in which the opening 42 is completely closed, as shown in Figure 7, and an open position in which the opening 42 is at its maximum, as shown in Figure 8.

[0059] Advantageously, the opening 42 may be protected by a breathable and waterproof filter to prevent impurities from entering the compression chamber 40. Such filters are known to those skilled in the art.

[0060] Advantageously, and with reference to FIG. 9, the timepiece may comprise a mechanism for closing said opening 42 of the compression chamber 40 after the sound has been generated, for example outside the striking time. Such a mechanism makes it possible to prevent the ingress of impurities when the vibration generator is not in use. In particular, when the opening 42 is a side opening, the closing mechanism may comprise a closing member 46, such as a ring, controlled by the striking mechanism so as to automatically close the opening 42 after the striking has been completed. Such a mechanism is described, for example, in Swiss Patent No. 704940, which is incorporated herein by reference.

[0061] If the membrane 18 is arranged on the back cover 4 and the sound is generated from the back cover side, it is also possible to provide a reflector configured to enable the generated sound to raise the side of the watch. Such a reflector is, for example, arranged on the outside of the back cover, surrounding the back cover and having a conical outer wall directed towards the watch.

[0062] The watch according to the invention allows a significant sound amplification: the first amplification ratio, achieved via the lever 20, is of the order of 10 to 16, and the second amplification ratio, due to the ratio between the moving surface area of ​​the membrane 18 and the opening 42 (surface area ratio of 20 to 30), is of the order of 1.5. The total amplification ratio achieved by the watch according to the invention can obtain a sound of more than 80 dB, or even 90 dB, compared to 60 dB for a standard minute repeater.

[0063] Furthermore, the construction and mounting of the amplifier makes it possible to isolate the vibration generator and the membrane from the movement, the frame and the intermediate part, so that all vibrations are directed to the membrane through the lever without passing through the movement, and therefore little or no undesirable sounds are obtained, which are generally associated with the vibrations of the movement components.

[0064] Furthermore, the striking force on the gongs may be increased without affecting the vibration of the movement components.

[0065] Furthermore, since the amplifier with the membrane is integrated into the back or bezel, the movement and gongs can be easily accessed and adjusted by simply dismantling the back or bezel.

[0066] Finally, the construction of the amplifier with the membrane is such that the tightness of the case does not affect the sound volume, unlike the principle of all other minute repeaters, for example. This is because the membrane, together with its suspension, makes the system leakproof, except for the compression chamber 40, which may be made leakproof by a filter system.

Claims

1. A timepiece (1) comprising a case (2) having an intermediate part (3), a back cover (4) and a bezel (5), a movement and a vibration generator housed in said case (2) adapted to generate at least one sound, a vibration amplifier (16) for amplifying the vibrations generated by said vibration generator, and a membrane (18) adapted to receive said amplified vibrations and generate a sound from the inside towards the outside of the timepiece, said vibration amplifier (16) being pivotally mounted on a support (22) in a pivot plane non-parallel to the plane of said membrane (18) and cooperating with said vibration generator to generate vibrations. A timepiece (1), comprising a lever (20) configured to be actuated by a transmission member (28) transmitting to the lever (20), characterized in that the lever (20) is integral with the membrane (18) so as to translate together with the membrane (18) at least in the pivot plane, such that a movement of the transmission member (28) generated by the vibrations of the transmission member (28) connected to the vibration generating device and transmitted to the membrane (18) via the lever (20) actuated by the transmission member (28) generates an amplified movement of the membrane (18), thereby generating an amplified sound.

2. 2. Timepiece according to claim 1, characterized in that the vibration amplifier (16) is separate from the movement.

3. 3. Timepiece according to claim 1 or 2, characterized in that the support (22) of the lever (20) is attached to the bezel (5) or to the back cover (4) or to the movement via a separating element (35) between the movement and the support (22).

4. 4. Timepiece according to claim 1, characterized in that, when the support (22) of the lever (20) is attached to the bezel (5) and to the back cover (4), respectively, the bezel (5) and the back cover (4) are respectively assembled to the intermediate part (3) via a separating element.

5. Timepiece according to any one of the preceding claims, characterized in that the pivot plane of the lever (20) is perpendicular to the plane of the membrane (18).

6. 6. Timepiece according to any one of the preceding claims, characterized in that the lever (20) is pivotally attached to the support (22) via a pin (26) or a flexible ball joint (24).

7. 7. Timepiece according to any one of claims 1 to 6, characterized in that the lever (20) is pivotally mounted on the support (22) and has a first end (20a) integral with the transmission member (28) and a second end (20b) integral with the membrane (18) so as to translate at least in the pivot plane.

8. 8. Timepiece according to any one of claims 1 to 7, characterized in that the connection point between the lever (20) and the membrane (18) is located at a distance from the centre of the membrane that is less than 40% of the width of the membrane.

9. A watch as described in claim 8, characterized in that the connection point is positioned at a distance from the center of the membrane that is less than 20% of the width of the membrane.

10. A watch as described in claim 9, characterized in that the connection point is arranged in the center of the membrane (18).

11. Timepiece according to any one of the preceding claims, characterized in that it comprises a compression chamber (40) configured to amplify the sound generated by the movement of the membrane (18) before it emerges to the outside.

12. Timepiece according to claim 11, characterized in that said compression chamber (40) is closed by a wall arranged downstream of said membrane (18) and having at least one opening (42), the dimensions of which are chosen in relation to the surface area of ​​said membrane (18) as a function of the desired sound amplification.

13. 13. Timepiece according to claim 12, characterized in that it comprises adjustable closure means (44) of the opening (42) of the compression chamber (40), configured to make it possible to adjust the volume of the sound generated by the membrane.

14. 13. Timepiece according to claim 12, characterized in that it comprises a mechanism (46) for closing said opening (42) of said compression chamber (40), configured to close said opening (42) after said sound has been generated.

15. A timepiece according to any one of claims 1 to 14, characterized in that the vibration generating device is a striking gong (14) configured to be struck by a striking hammer (12), the striking gong (14) being integral with the transmission member (28), and the transmission member (28) being integral with the lever (20).

16. 15. Timepiece according to any one of claims 1 to 14, characterized in that the vibration generating device is a rotating disk with engraved grooves configured to generate sound, and the transmission member (28) is a hand that is integral with the lever (20) and is configured to follow the grooves of the disk.

17. 15. A timepiece according to any one of claims 1 to 14, characterized in that the vibration generating device is a music box with a vibrating blade fixed by a stud, and the transmission member is integral with the stud and with the lever (20).

Images