Shock-absorbing balance plate for direct-pulse escapement mechanism

Abstract

The invention relates to a balance wheel plate (26) configured to cooperate with a direct impulse escapement mechanism (1), the balance wheel plate (26) being provided with a first impulse pallet (30) adapted to cooperate with an escape wheel (10) of the escapement mechanism (1), such that, during the impulse phase, the escape wheel (10) imparts a direct impulse to the balance wheel plate (26) to actuate the balance wheel (20), the first impulse pallet (30) being arranged radially to an axis of rotation (24) of the balance wheel (20), the balance wheel plate (26) comprising a rigid portion (3) configured to be assembled to the balance wheel (20), characterized in that the balance wheel plate (26) comprises a first elastically flexible portion (5) on which the impulse pallet (30) is mounted, the first flexible portion (5) being configured to allow movement of the impulse pallet (30) in the direction of the axis of rotation (24) of the pendulum (20),preferably substantially radial, in case of impact with the escape wheel (10). The invention also relates to a direct impulse escapement mechanism (1), and a clock movement comprising such a direct impulse escapement mechanism (1).

Description

Technical field of the invention

[0001] The present invention relates to a shock-resistant balance wheel for use with a direct impulse escapement mechanism. The present invention also relates to a direct impulse escapement mechanism and a watch movement comprising such an escapement mechanism. Technological background

[0002] In mechanical watchmaking, different kinds of escapement mechanisms are used, the best known being the Swiss lever escapement mechanism, which works with an indirect impulse produced by a tooth of the escape wheel against an impulse pallet of the anchor.

[0003] There are other escapement mechanisms that operate with a direct impulse, such as the expansion escapement, the natural escapement, the coaxial escapement, or the Robin escapement.

[0004] In these escapements, the balance wheel plate includes at least one impulse pallet cooperating directly with the escape wheel of the escapement mechanism.

[0005] The impulse pallet receives an impulse from a tooth of the escape wheel to restart the balance wheel. This impulse is generally oriented tangentially to the escape wheel.

[0006] However, as the balance wheel is close to the escape wheel, there is a risk of collision between the pallet and the escape wheel in the event of a shock during carrying, as the balance wheel is likely to move. Summary of the invention

[0007] The present invention aims to remedy the problems mentioned above by providing a balance wheel plate for a direct impulse escapement mechanism capable of withstanding shocks.

[0008] To this end, the present invention relates to a balance wheel plate configured to cooperate with a direct impulse escapement mechanism, the plate being provided with an impulse pallet adapted to cooperate with an escape wheel of the escapement mechanism, so that in the impulse phase, the escape wheel gives the balance wheel plate a direct impulse to actuate the balance wheel, the first impulse pallet being arranged radially to an axis of rotation of the balance wheel, the balance wheel plate comprising a rigid part configured to be assembled to the balance wheel.

[0009] The invention is remarkable in that the balance wheel plate has a first elastically flexible part on which the impulse pallet is mounted, the first flexible part being configured to allow a displacement of the impulse pallet in the direction of the axis of rotation of the balance wheel, preferably substantially radial, in the event of a shock with the escape wheel.

[0010] Thus, in the event of a collision between the escape wheel and the impulse paddle of the platter, the first flexible part deforms to absorb it and avoid damaging the elements involved.

[0011] Indeed, unlike the impulse of the escape wheel, which is essentially tangential, the collision between the plate and the escape wheel is essentially radial. Therefore, such a flexible part allows the shock to be absorbed without impairing the operation of the direct impulse escapement mechanism.

[0012] According to a particular embodiment of the invention, the flexible part comprises a translation table on which the impulse pallet is suspended, the translation table comprising at least one flexible blade configured to avoid a substantially tangential displacement of the impulse pallet with respect to the axis of rotation of the balance wheel, in particular when the impulse is given by the escape wheel.

[0013] According to a particular embodiment of the invention, the translation table comprises at least two flexible blades arranged each on a different side of the impulse paddle, each flexible blade connecting the impulse paddle to the rigid part to allow it to move by bending the flexible blades.

[0014] According to a particular embodiment of the invention, the translation table comprises at least one pair of flexible blades arranged on one side of the impulse paddle, each flexible blade connecting the impulse paddle to the rigid part to allow it to move by bending the flexible blades.

[0015] According to a particular embodiment of the invention, the translation table comprises two pairs of flexible blades arranged each on a different side of the impulse paddle, each flexible blade connecting the impulse paddle to the rigid part to allow it to move by bending the flexible blades.

[0016] According to a particular embodiment of the invention, the displacement of the pallet is substantially radial with respect to the axis of rotation of the rocker arm.

[0017] According to a particular embodiment of the invention, the balance wheel plate includes a second impulse pallet extending in the plane of the balance wheel plate.

[0018] According to a particular embodiment of the invention, the balance wheel plate includes a second flexible part on which the second impulse pallet is mounted.

[0019] According to a particular embodiment of the invention, the second flexible part is provided with a second translation table comprising at least one flexible blade configured to avoid a substantially tangential displacement of the second impulse pallet with respect to the axis of rotation of the balance wheel, in particular when the impulse is given by the escape wheel.

[0020] According to a particular embodiment of the invention, the second translation table comprises at least two flexible blades arranged either on a different side of the second impulse paddle or on the same side of the second impulse paddle, each flexible blade connecting the second impulse paddle to the rigid part to allow it to move by bending the flexible blades.

[0021] According to a particular embodiment of the invention, the rigid part comprises arms arranged perpendicularly to each other, the impulse paddle(s) being arranged between two arms of the rigid part.

[0022] According to a particular embodiment of the invention, the rigid part comprises an enlarged arm equipped with the rocker arm pin.

[0023] According to a particular embodiment of the invention, the arms of the rigid part form a cross.

[0024] The invention also relates to a direct impulse escapement mechanism, the escapement mechanism comprising at least one rotating escape wheel, the escapement mechanism comprising such a balance plate, the balance plate being rotating about the axis of rotation of the balance wheel, so that in the impulse phase, the escape wheel gives the balance plate a direct impulse to actuate the balance wheel.

[0025] According to a particular embodiment of the invention, the escapement mechanism is a natural escapement comprising a second escape wheel and an anchor.

[0026] The invention further relates to a clock movement comprising such a direct impulse escapement mechanism, for example a natural escapement mechanism. Brief description of the figures

[0027] Other features and advantages of the present invention will become clearer from the following detailed description of an embodiment of a balance wheel pallet for a natural escapement mechanism, this example being given purely for illustrative purposes and not as a limitation, only in connection with the accompanying drawing in which: there figure 1 is a perspective view of a natural escapement comprising a shock-resistant balance wheel according to a first embodiment of the invention; the figure 2 is another perspective view of the natural escape of the figure 1 ; there figure 3 is a top view of the natural exhaust of the figure 1 ; there figure 4 is a top view of the shock-absorbing balance plate according to the first embodiment of the invention; the figure 5 is a perspective view of the first embodiment of the shock-resistant balance plate according to the invention; the figure 6is a top view of a second embodiment of a shock-resistant balance plate according to the invention; and the figure 7 is a top view of a third embodiment of a shock-absorbing balance plate according to the invention. Detailed description of the invention

[0028] The invention relates to a shock-resistant balance wheel 26 configured to cooperate with an escape wheel in a direct impulse escapement mechanism.

[0029] In the description below, the balance wheel plate 26 is configured to operate in a natural escapement mechanism, the operation of which is described in detail in patent EP4105731.

[0030] On the figures 1 to 3, designated as a whole by the general numerical reference 1, the natural escapement is arranged to be driven by a mobile driving wheel, not shown in the figures, which meshes with a pinion 4 fixedly mounted on an axis 6 of a first escape wheel 10. This first escape wheel 10 meshes in turn via a first drive tooth 12 with a second drive tooth 14 of a second escape wheel 16 which pivots around an axis 18.

[0031] The natural escapement 1 also includes a balance wheel 20, which has a balance wheel 22 on an axle 24, to which a balance plate 26 is fitted. This balance plate 26 carries a balance pin 28 as well as a first and second impulse pallet 30 and 32, the respective roles of which will be described below. Preferably, the impulse pallets are rigid.

[0032] The natural escapement 1 also includes an anchor 34 pivoted around an anchor stem 36. This anchor 34 has an anchor body 38 which carries a fork 40 formed of a first and a second horn 42a and 42b as well as a dart 44. This dart 44 cooperates with the balance wheel plate 26 in order to prevent accidental displacements of the fork 40 outside of the periods commonly called supplementary arcs, periods during which the balance wheel plate 26 is close to its rest position called the lift angle.

[0033] The anchor body 38 comprises a first and a second arm 46a and 46b which are preferably, but not exclusively, arranged symmetrically on either side of the fork 40. First and second levers 48a, 48b, pivoted about respective pivot axes 50 and 52, are connected to the first and second arms 46a, 46b of the anchor body 38 via a pivot joint 53. In this simplified embodiment, the first lever 48a is made of a single piece and has a geometry that ensures the function of a first stop pallet to temporarily block the first escape wheel 10 during one operating cycle of the natural escapement 1, and the second lever 48b has a geometry that ensures the function of a second stop pallet to temporarily block the second escape wheel 16 during the same operating cycle of the natural escapement 1.

[0034] The first and second levers 48a, 48b each have a lug 54, respectively 56, which protrudes into an oblong opening 58, respectively 60, formed in the first and second arms 46a, 46b of the anchor body 38. Of course, the lugs 54 and 56 could be carried by the first and second arms 46a, 46b, and the oblong openings 58, 60 could be formed in the first and second levers 48a, 48b. Thus, by engaging the lugs 54, 56 in the oblong openings 58, 60, the first and second levers 48a, 48b are able to pivot relative to the first and second arms 46a, 46b of the anchor body 38.

[0035] On the Figures 4 and 5 , the first embodiment of the balance wheel plate 26 includes a rigid part 3. The rigid part 3 here has a cross shape, and includes four arms 15, 17 arranged perpendicularly to each other.

[0036] The rigid part 3 includes a central opening 19 so that it can be mounted on the axis 24 of the balance wheel 20. An enlarged arm 15 includes the balance wheel pin 28. Each pallet 30, 32 is arranged between two of the three other arms 17.

[0037] According to the invention, the balance wheel plate 26 comprises a first elastically flexible part 5, on which the first impulse pallet 30 is mounted.

[0038] In addition, the balance wheel plate 26 includes a second elastically flexible part 13, on which the second impulse pallet 32 ​​is mounted.

[0039] Each flexible part 5, 13 is arranged between two arms 17 of the rigid part 15, for the corresponding impulse paddle 30, 32.

[0040] Each flexible part 5, 13 includes a translation table 7, 21 on which an impulse paddle 30, 32 is suspended, and which includes flexible blades 9, 11.

[0041] The translation table 7, 21 includes at least one flexible blade 9 arranged on each side of the impulse paddle 30, 32. Each flexible blade 9 connects a different arm 17 of the rigid part 15 to an impulse paddle 30, 32. Preferably, the flexible blades 9 are arranged substantially perpendicular to each impulse paddle 30, 32 in the rest position of the flexible part 5, 13.

[0042] Preferably, each translation table 7, 21 comprises at least one pair of flexible blades 9, 11 arranged on each side of the pallet. The flexible blades 9, 11 are substantially parallel and arranged in the same plane, that of the rocker plate 26.

[0043] The impulse paddles 30, 32 are arranged radially and extend in the same plane as that of the translation table 7, 21. The impulse paddles 30, 32 are arranged perpendicularly to each other.

[0044] Therefore, if an escape wheel 10, 16 collides with a pulse pallet 30, 32, the pulse pallet 30, 32 moves radially in the direction of the axis of rotation 24 of the balance wheel 20 due to the bending of the flexible blades 9,11 of the translation tables 7, 21.

[0045] On the other hand, as the flexible blades 9,11 are arranged tangentially to the axis of rotation 24 of the balance wheel 20, these flexible parts 5, 13 substantially avoid a tangential displacement of the impulse paddles 30, 32 with respect to the axis of rotation 24 of the balance wheel 20.

[0046] Thus, the flexible part 5, 13 does not deform or hardly deforms in this direction, so that the direct impulse given by the first 10 or the second escape wheel 16 to an impulse pallet 30, 32 is transmitted to the balance wheel 20, with minimal energy loss.

[0047] There figure 6shows a second embodiment of a balance plate 29 equipped with two flexible parts 5, 13 each comprising a translation table 39 equipped with a single flexible blade 41 on which each pallet 30, 32 is suspended.

[0048] The rigid part 43 has a cross shape and includes a central opening 19, two lateral arms 37, one on each side of the central opening 19, a rear axial arm 45 equipped with the ellipse, and a front axial arm 49.

[0049] Each single flexible blade 41 connects a pallet 30, 32 to a different lateral arm 37 of the rigid part 35. Each single flexible blade 41 is connected at one end to one end of a lateral arm 37, and includes a movable free end 53 on the other side. The blades are oriented from the lateral arms 37 towards the front axial arm 49.

[0050] The pallets 30, 32 are arranged in the middle of the single flexible blade 41.

[0051] The front axial arm 49 is equipped with lateral stops 51 to retain the free ends 53 of the flexible blades 41 in order to prevent outward bending of the flexible blades 41. However, the flexible blades can deform in the direction of the central opening 19.

[0052] The flexible blades 41 can deform by bringing their free end 53 closer to the central opening 19. Thus, in the event of a shock, the pallet 30, 32 is pushed towards the axis of rotation 24 of the balance wheel by the deformation of the single flexible blade 41.

[0053] The third embodiment of the figure 7shows a balance wheel platform 25 comprising two pallets 30, 32 suspended by two flexible parts 5, 13. The flexible parts 5, 13 each comprise a translation table 39 having a pair of flexible blades 31 arranged on one side of the first impulse pallet 30. The rigid part 33 has two lateral arms 47 extending on either side of the central opening 19 and a rear portion 35 comprising the ellipse 28.

[0054] Each paddle 30, 32 is held on one side by the two flexible blades 31 of the pair. The flexible blades 31 connect the impulse paddle 30, 32 at one end to the free end of a lateral arm 47 of the rigid part 33 at the other end, so as to allow it to move by bending of the flexible blades 31.

[0055] Thus, in the event of a radial shock, the pallet 30, 32 is pushed towards the axis of rotation 24 of the rocker 20 by the deformation of the blades 31 of the pair of flexible blades.

[0056] Naturally, the invention is not limited to the balance wheel embodiments described with reference to the figures, and variations could be envisaged without departing from the scope of the invention. For example, in one particular embodiment, the balance wheel comprises a single impulse pallet configured to cooperate with an escapement mechanism comprising a single escape wheel. Such an escapement mechanism is, for example, a detent escapement, a coaxial escapement, or a Robin escapement, for which only one impulse pallet is required on the balance wheel.

Claims

1. Balance wheel plate (25, 26, 29) configured to cooperate with a direct impulse escapement mechanism (1), the balance wheel plate (25, 26, 29) being provided with a first impulse pallet (30) adapted to cooperate with an escape wheel (10) of the escapement mechanism (1), so that in the impulse phase, the escape wheel (10) gives the balance wheel plate (25, 26, 29) a direct impulse to actuate the balance wheel (20), the first impulse pallet (30) being arranged radially to a rotation axis (24) of the balance wheel (20), the balance wheel plate (25, 26, 29) having a rigid part (3) configured to be assembled to the balance wheel (20), characterized in thatthe balance wheel plate (25, 26, 29) has a first elastically flexible part (5) on which the impulse pallet (30) is mounted, the first flexible part (5) being configured to allow a displacement of the impulse pallet (30) in the direction of the axis of rotation (24) of the balance wheel (20), in case of impact with the escape wheel (10).

2. Balance plate according to claim 1, characterized in that the first flexible part (5) includes a translation table (7, 39) on which the impulse pallet (30) is suspended, the translation table (7) including at least one flexible blade (9) configured to avoid a substantially tangential displacement of the impulse pallet (30) with respect to the axis of rotation (24) of the balance wheel (20), particularly when the impulse is given by the escape wheel.

3. Balance plate according to claim 2, characterized in thatthe translation table (7, 39) includes at least two flexible blades (9) arranged each on a different side of the impulse paddle (30), each flexible blade (9) connecting the impulse paddle (30) to the rigid part (3) to allow it to move by bending the flexible blades (9).

4. Balance plate according to claim 2, characterized in that the translation table (7, 39) includes at least one pair of flexible blades (31) arranged on one side of the impulse paddle (30), each flexible blade (31) connecting the impulse paddle (30, 32) to the rigid part (3) to allow it to move by bending the flexible blades (9).

5. Balance plate according to claim 2, characterized in thatthe translation table (7) includes two pairs of flexible blades (9, 11) arranged each on a different side of the impulse paddle (30), each flexible blade (31) connecting the impulse paddle (30, 32) to the rigid part (3) to allow it to move by bending the flexible blades (9).

6. Balance wheel according to any one of the preceding claims, characterized in that the displacement of the pallet (30) is substantially radial with respect to the axis of rotation (24) of the rocker (20).

7. Balance wheel according to any one of the preceding claims, characterized in that it includes a second impulse pallet (32) extending in the plane of the balance wheel plate (25, 26, 29).

8. Balance plate according to claim 7, characterized in that it includes a second flexible part (13) on which the second impulse paddle (32) is mounted.

9. Balance plate according to claim 8, characterized in thatthe second flexible part (13) is provided with a second translation table (21, 39) comprising at least one flexible blade (9) configured to avoid a substantially tangential displacement of the second impulse pallet (32) with respect to the axis of rotation (24) of the balance wheel (20), particularly when the impulse is given by the escape wheel.

10. Balance plate according to claim 9, characterized in that the second translation table (21, 39) includes at least two flexible blades (31) arranged either on a different side of the second impulse paddle (30) or on the same side of the second impulse paddle (30), each flexible blade (9) connecting the second impulse paddle (30) to the rigid part (3) to enable it to move by bending the flexible blades (9).

11. Balance wheel according to any one of the preceding claims, characterized in thatthe rigid part (3) includes arms (15, 17) arranged perpendicularly to each other, the impulse paddle(s) (30, 32) being arranged between two arms (17) of the rigid part (3).

12. Balance plate according to claim 11, characterized in that the rigid part (3) includes an enlarged arm (15) equipped with a rocker arm pin (28).

13. Balance wheel according to claim 11 or 12, characterized in that the arms of the rigid part (3) form a cross.

14. Direct impulse escapement mechanism (1), the escapement mechanism comprising at least one rotatable escape wheel (10), characterized in thatit includes a balance wheel plate (25, 26, 29) according to any one of the preceding claims, the balance wheel plate (25, 26, 29) being movable in rotation about the axis of rotation (24) of a balance wheel (20), so that in the impulse phase, the escape wheel (10) gives the balance wheel plate (25, 26, 29) a direct impulse to actuate the balance wheel (20).

15. Direct impulse escape mechanism according to claim 14, characterized in that It is a natural escapement comprising a second escape wheel (16) and an anchor (34).

16. Clockwork movement, characterized in that it includes a direct impulse escapement mechanism (1) according to claim 14 or 15.

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