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EP-4740071-A1 - ACOUSTIC DEVICE FOR A STRIKING TIMEPIECE

EP4740071A1EP 4740071 A1EP4740071 A1EP 4740071A1EP-4740071-A1

Abstract

The present invention relates to an acoustic device (10) for a striking timepiece, including an acoustic membrane (20), at least one piezoelectric element (30; 30a, 30b; 30c; 32) arranged to cooperate with the acoustic membrane (20) and at least one electric circuit (40a, 40b) incorporating the piezoelectric element. The acoustic device (10) further includes at least one gong (12, 14) that can be struck by a hammer. The assembly comprising the piezoelectric element (30; 30a, 30b; 32) and the electric circuit (40a, 40b) is configured to adjust resonant frequencies of the acoustic membrane (20) according to the resonant frequencies of the at least one gong (12, 14). The invention also relates to a striking timepiece, in particular a clock or watch, comprising the acoustic device (10).

Inventors

  • Robuschi, Nicolò
  • THUET, Arnaud
  • PINA, Aurélien

Assignees

  • Manufacture d'Horlogerie Audemars Piguet SA

Dates

Publication Date
20260513
Application Date
20240618

Claims (15)

  1. 1. Acoustic device (10) for a striking piece, comprising an acoustic membrane (20), at least one piezoelectric element (30; 30a, 30b; 30c; 32) arranged to cooperate with the acoustic membrane (20) and at least one electrical circuit (40a, 40b) integrating the piezoelectric element, characterized in that the acoustic device (10) further comprises at least one gong (12, 14) which can be struck by a hammer and in that the assembly comprising the piezoelectric element (30; 30a, 30b; 32) and the electrical circuit (40a, 40b) is configured to adjust resonance frequencies of said membrane (20) as a function of the resonance frequencies of said at least one gong (12, 14).
  2. 2. Acoustic device (10) according to claim 1, in which each piezoelectric element (30; 30a, 30b) is arranged directly in contact with the acoustic membrane (20) and preferably has a shape at least partially complementary to that of the acoustic membrane (20).
  3. 3. Acoustic device (10) according to claim 2, wherein the acoustic membrane (20) is circular in shape, said at least one piezoelectric element (30a, 30b, 30c) being circular or partially circular in shape.
  4. 4. An acoustic device (10) according to claim 3, wherein said at least one piezoelectric element (30c) has an at least partially annular shape and is arranged along at least a portion of the periphery of the acoustic membrane (20) to modulate its resonance frequencies when said membrane (20) is radially stressed by said at least one piezoelectric element (30c). AUDEMA-29-PCT
  5. 5. Acoustic device (10) according to one of claims 1 to 3, in which at least one face of the acoustic membrane (20) is covered by at least one piezoelectric element to occupy at least 70% of its surface, preferably at least 80%, or even at least 90% of its surface.
  6. 6. Acoustic device (10) according to one of the preceding claims, comprising at least one piezoelectric element (30; 30a, 30b; 30c; 32) configured to be powered by an electrical source (60) integrated into the electrical circuit (40a, 40b) in order to operate in an active mode.
  7. 7. Acoustic device (10) according to the preceding claim, in which the electrical source (60) is one or more other piezoelectric elements of the device (10).
  8. 8. Acoustic device (10) according to claim 1 or 2, further comprising a peripheral element (50) in contact with the acoustic membrane (20) by its periphery, the piezoelectric element (32) being integrated into the peripheral element (50) so that any expansion or retraction of the piezoelectric element (32) exerts a voltage variation on the acoustic membrane (20) to modulate its resonance frequencies.
  9. 9. Acoustic device (10) according to one of the preceding claims, comprising several timbres (12, 14), in which an electrical circuit is assigned to each timbre and has its own characteristics making it possible to adjust the resonance frequencies of said membrane (20) as a function of the resonance frequencies of the timbre to which the electrical circuit is assigned.
  10. 10. Acoustic device (10) according to one of the preceding claims, comprising several timbres (12, 14), in which a piezoelectric element (30a, 30b) is assigned to each timbre and has specific characteristics making it possible to adjust the resonance frequencies of said membrane (20) as a function of the resonance frequencies of the AUDEMA-29-PCT timbre to which the piezoelectric element (10a, 30b) is assigned.
  11. 11. Acoustic device (10) according to one of the preceding claims, in which at least one electrical circuit (40a, 40b) comprises a switch (70) making it possible to open or close the electrical circuit in order to respectively activate or disconnect said at least one piezoelectric element integrated therein.
  12. 12. Acoustic device (10) according to one of the preceding claims, in which the assembly comprising the piezoelectric element and the electrical circuit is configured to further distance the resonance frequencies of the membrane and the timbre.
  13. 13. A striking timepiece comprising the acoustic device (10) according to one of claims 1 to 8 and a hammer arranged to strike the gong (12, 14) of the acoustic device (10).
  14. 14. A striking timepiece comprising the acoustic device (10) according to claim 9 or 10 and according to claim 11, and several hammers arranged to strike the respective gongs and in which the switch (70) is actuated by a movement of a hammer or by a striking trigger member.
  15. 15. A striking timepiece according to claim 13 or 14, wherein said at least one piezoelectric element (30; 30a, 30b; 30c; 32) is arranged on a face of the acoustic membrane (20) located opposite a gong (12, 14). AUDEMA-29-PCT

Description

Acoustic device for ringing room Technical field [0001] The present invention relates to an acoustic device for a striking part, comprising a membrane whose resonance frequencies are adjustable by piezoelectric effect. The invention also relates to a striking part, in particular a timepiece, comprising such an acoustic device. State of the art [0002] Striking parts and in particular striking timepieces, for example of the grand strike or minute repeater type, are well known. CH714635 and EP2942675 for example disclose a striking timepiece comprising a watch case housing an acoustic membrane and a watch movement provided with a striking mechanism. This mechanism comprises at least one gong and a hammer for striking the gong. The sound produced by the impact of the hammer on the gong causes the gong and the membrane to vibrate, which contributes to the sound transmission between the inside and the outside of the watch case. [0003] The disadvantage of the above-mentioned timepiece is that the acoustic membrane operates in forced mode and does not resonate. The membrane is therefore not used to its full potential. [0004] There are also watches comprising an acoustic membrane associated with a piezoelectric element in order to adjust the resonance frequency of the acoustic membrane. For example, FR2466903 discloses a mechanical watch equipped with an assembly consisting of a AUDEMA-29-PCT acoustic membrane and a piezoelectric element. The piezoelectric element is, according to one method of operation, controlled by an electronic circuit in order to vibrate the acoustic membrane to produce an audible sound. The watch further comprises a mechanism for adjusting the resonant frequency of the acoustic membrane. This mechanism is mounted in the bottom of the case and comprises a rotating arm in contact with the membrane and movable to adjust its resonant frequency. This makes it possible to modify the frequency of the membrane-piezoelectric element assembly in order to amplify the sound. [0005] The disadvantage of the above-mentioned mechanical watch lies in the quality of the sound emitted which depends partly on the characteristics of the acoustic membrane. [0006] An object of the present invention is therefore to provide an acoustic device for a ringing piece so that the latter can emit a sound of better quality. [0007] Another object of the present invention is to provide an acoustic device for a ringing piece which allows the latter to attenuate the sound amplitude to obtain a mute mode. Brief summary of the invention [0008] At least some of these aims are achieved in particular by an acoustic device for a striking piece, comprising an acoustic membrane, at least one piezoelectric element arranged to cooperate with the acoustic membrane and at least one electrical circuit integrating the piezoelectric element, in particular by its electrodes which, typically, can be constituted by its larger faces. The acoustic device further comprises at least one gong which can be struck by a hammer. The assembly comprising the piezoelectric element and the electrical circuit is AUDEMA-29-PCT configured to adjust resonance frequencies of said membrane as a function of the resonance frequencies of said at least one timbre. [0009] According to one embodiment, each piezoelectric element is arranged directly in contact with the acoustic membrane and preferably has a shape at least partially complementary to that of the acoustic membrane. [0010] According to one embodiment, the acoustic membrane is circular in shape. The piezoelectric element is circular or partially circular in shape. [0011] According to one embodiment, at least one piezoelectric element has an at least partially annular shape. The piezoelectric element is arranged along at least a portion of the periphery of the acoustic membrane. This makes it possible to modulate the resonance frequencies of the membrane when the latter is radially stressed by the piezoelectric element. [0012] According to one embodiment, at least one face of the acoustic membrane is covered by at least one piezoelectric element to occupy at least 70% of its surface, preferably at least 80%, or even at least 90% of its surface. [0013] According to one embodiment, the acoustic device comprises at least one piezoelectric element configured to be powered by an electrical source integrated into the electrical circuit in order to operate in an active mode. [0014] According to one embodiment, the electrical source consists of one or more other piezoelectric elements of the acoustic device. AUDEMA-29-PCT [0015] According to one embodiment, the acoustic device further comprises a peripheral element in contact with the acoustic membrane by its periphery. The piezoelectric element is integrated into the peripheral element so that any expansion or retraction of the piezoelectric element exerts a voltage variation on the acoustic membrane to modulate its resonance frequencies. [0016] According to one em