Impact resistant balance wheel plate for direct impulse escapement

Abstract

The invention relates to a balance plate (26) configured to engage with a direct impulse escapement (1), the balance plate being equipped with a first impulse pallet stone (30) designed to engage with an escape wheel (10) in the escapement, such that, in the impulse phase, the escape wheel gives a direct impulse to the balance plate to actuate a balance (20), the first impulse pallet stone being arranged radially to the axis of rotation (24) of the balance, the balance plate comprising a rigid portion (3) configured to be assembled to the balance, characterized in that the balance plate comprises a first elastically flexible portion (5) on which the impulse pallet stone is mounted, the first flexible portion being configured so that the impulse pallet stone can move, preferably substantially radially, along the axis of rotation of the balance in the event of a collision with the escape wheel. The invention also relates to a direct impulse escapement (1) and to a timepiece movement comprising such a direct impulse escapement (1).

Description

Technical Field

[0001] This invention relates to a shock-resistant balance plate for engagement with a direct impulse escapement. The invention also relates to a direct impulse escapement and a watch movement incorporating such an escapement. Background Technology

[0002] In mechanical watches, various types of escapement mechanisms are used, the most common being the Swiss fork escapement, which works by the indirect impact generated by the teeth on the escape wheel hitting the fork stone on the escape fork.

[0003] Other escapement mechanisms that utilize direct impact to function exist, such as the ratchet escapement, the natural escapement, the coaxial escapement, or the robin escapement.

[0004] In these escapements, the balance plate includes at least one impact escapement fork that engages directly with the escape wheel on the escapement.

[0005] The impact escapement fork receives an impact from the teeth on the escape wheel to restart the balance wheel. This impact is typically tangential to the escape wheel orientation.

[0006] However, when the balance plate is close to the escape wheel, there is a risk of collision between the escape fork and the escape wheel in the event of an impact on the retainer, because the balance wheel is easily moved. Summary of the Invention

[0007] The present invention aims to correct the above-mentioned problems by providing a balance wheel plate for a direct impact escapement mechanism that can withstand impacts.

[0008] For this purpose, the present invention relates to a balance plate configured to engage with a direct impact escapement mechanism, the balance plate being fitted with an impact escape fork designed to engage with the escape wheel in the escapement mechanism, such that during the impact phase, the escape wheel delivers a direct impact to the balance plate to actuate the balance wheel, the first impact escape fork being arranged radially to the axis of rotation of the balance wheel, and the balance plate including a rigid portion configured to be assembled to the balance wheel.

[0009] The significant feature of the invention is that the balance wheel plate includes a first flexible portion thereon on which an impact escapement fork is mounted, the first flexible portion being configured such that the impact escapement fork can move along the axis of rotation of the balance wheel upon impact with the escape wheel, preferably substantially radially.

[0010] Therefore, in the event of an impact between the escape wheel and the impact escape fork on the plate, the first flexible part twists to absorb the impact and prevent damage to the working components.

[0011] In fact, unlike the essentially tangential impact from the escape wheel, the collision between the plate and the escape wheel is essentially radial. Therefore, this flexible section allows for the absorption of impacts without affecting the function of the escapement mechanism in direct impact.

[0012] According to a particular embodiment of the invention, the flexible portion includes a translation platform on which the impact escapement fork is suspended. The translation platform includes at least one flexible blade configured to prevent the impact escapement fork from moving substantially tangentially relative to the axis of rotation of the balance wheel, particularly when an impact is delivered by the escapement wheel.

[0013] According to a specific embodiment of the invention, the translation stage includes at least two flexible blades, each flexible blade being arranged on a different side of the impact escape fork, each flexible blade connecting the impact escape fork to a rigid portion so that it can be moved by deflection of the flexible blade.

[0014] According to a specific embodiment of the invention, the translation stage includes at least a pair of flexible blades arranged on one side of the impact escape fork, each flexible blade connecting the impact escape fork to a rigid portion so that it can be moved by deflection of the flexible blade.

[0015] According to a specific embodiment of the invention, the translation stage includes two pairs of flexible blades, each pair of flexible blades being arranged on different sides of the impact escape fork, each flexible blade connecting the impact escape fork to a rigid portion so that it can be moved by deflection of the flexible blade.

[0016] According to a particular embodiment of the invention, the movement of the escapement fork is substantially radial relative to the axis of rotation of the balance wheel.

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

[0018] According to a specific embodiment of the invention, the balance wheel plate includes a second flexible portion thereon on which a second impact escapement fork is mounted.

[0019] According to a particular embodiment of the invention, the second flexible portion is equipped with a second translation stage, which includes at least one flexible blade configured to prevent the impact escape fork from moving substantially tangentially relative to the axis of rotation of the balance wheel, particularly when impacted by the escape wheel.

[0020] According to a specific embodiment of the invention, the second translation stage includes at least two flexible blades, each flexible blade being arranged on a different side of the second impact escape fork or on the same side of the second impact escape fork, each flexible blade connecting the second impact escape fork to a rigid portion so that it can be moved by deflection of the flexible blade.

[0021] According to a particular embodiment of the invention, the rigid portion includes arms arranged perpendicularly to each other, and one or more impact escapement forks are arranged between the two arms on the rigid portion.

[0022] According to a specific embodiment of the invention, the rigid portion includes an enlarged arm fitted with a balance wheel pin.

[0023] According to a specific embodiment of the invention, the arm on the rigid portion forms a cross.

[0024] The present invention also relates to a direct impact escapement mechanism comprising at least one rotatable escape wheel, the escapement mechanism comprising a balance plate rotatably movable along the axis of rotation of the balance wheel, such that during the impact phase, the escape wheel delivers a direct impact to the balance plate to actuate the balance wheel.

[0025] According to a specific embodiment of the invention, the escapement mechanism is a natural escapement mechanism including a second escape wheel and an escape fork.

[0026] The present invention also relates to a watch movement that includes such a direct impact escapement, such as a natural escapement. Attached Figure Description

[0027] Other features and advantages of the invention will become clearer from the following detailed description of an embodiment of a balance wheel escapement fork for a natural escapement mechanism, which is given purely by way of non-limiting illustration only in conjunction with the accompanying drawings, in which: - Figure 1 This is a perspective view of a natural escapement mechanism including an impact-resistant balance wheel plate according to a first embodiment of the present invention; - Figure 2 yes Figure 1 Another perspective view of the natural escapement mechanism in the image; - Figure 3 yes Figure 1 A top view of the natural escapement mechanism in the image; - Figure 4 This is a top view of the impact-resistant balance wheel plate according to the first embodiment of the present invention; - Figure 5 This is a perspective view of a first embodiment of the impact-resistant balance wheel plate according to the present invention; - Figure 6 This is a top view of a second embodiment of the impact-resistant balance plate according to the present invention; and - Figure 7 This is a top view of a third embodiment of the impact-resistant balance plate according to the present invention. Detailed Implementation

[0028] The present invention relates to an impact-resistant balance plate 26, which is configured to engage the escape wheel in a direct impact escapement mechanism.

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

[0030] exist Figures 1 to 3 In the figure, referred to as a whole by general numeral reference numeral 1, the natural escapement is arranged to be driven by a drive mechanism (not shown) that engages with a pinion 4 fixed in a position on the axis 6 of the first escape wheel 10. The first escape wheel 10 then engages via a first drive tooth 12 with a second drive tooth 14 on a second escape wheel 16 that pivots about axis 18.

[0031] The natural escapement 1 also includes a balance wheel 20, which comprises a balance wheel 22 having a balance wheel plate 26 mounted on an axis 24. The balance wheel plate 26 carries the balance pin 28 and the first and second impact escapement forks 30 and 32, the respective functions of which will be described below. The impact escapement forks are preferably rigid.

[0032] The natural escapement 1 also includes an escape fork 34 that pivots about an escape fork pivot 36. The escape fork 34 includes an escape fork body 38 that carries a fork 40 formed by a first corner portion 42a, a second corner portion 42b, and a dart-shaped member 44. The dart-shaped member 44 engages with a balance wheel plate 26 to prevent the fork 40 from moving unintentionally outside a period commonly referred to as the residual arc, during which the balance wheel plate 26 approaches its locked position (referred to as the lift angle).

[0033] The escapement fork body 38 includes a first arm 46a and a second arm 46b, which are preferably, but not limitingly, symmetrically arranged on either side of the fork 40. The first link 48a and the second link 48b, pivoting about corresponding pivot axes 50 and 52, are connected to the first arm 46a and the second arm 46b on the escapement fork body 38 via pivot hinges 53. In this simplified embodiment, the first link 48a is made as a single piece and has a geometry that acts as a first stop escapement fork stone for temporarily locking the first escape wheel 10 when the natural escapement 1 is in an operating cycle, and the second link 48b has a geometry that acts as a second stop escapement fork stone for temporarily locking the second escape wheel 16 when the natural escapement 1 is in the same operating cycle.

[0034] First link 48a and second link 48b each carry a sergot 54 (correspondingly 56), which protrudes into a rectangular opening 58 (correspondingly 60) in the first arm 46a and the second arm 46b on the escapement fork body 38. Of course, sergots 54 and 56 can be carried by the first arm 46a and the second arm 46b, and rectangular openings 58 and 60 can be in the first link 48a and the second link 48b. Therefore, when sergots 54 and 56 are engaged in the rectangular openings 58 and 60, the first link 48a and the second link 48b can pivot relative to the first arm 46a and the second arm 46b on the escapement fork body 38.

[0035] exist Figure 4 and Figure 5 In the first embodiment of the balance wheel plate 26, a rigid portion 3 is included. In this example, the rigid portion 3 is cross-shaped and includes four arms 15, 17 arranged perpendicularly to each other.

[0036] The rigid part 3 includes a central opening 19, allowing it to be fitted onto the axis 24 of the balance wheel 20. The extended arm 15 includes a balance wheel pin 28. Each escapement fork stone 30, 32 is arranged between two of the three other arms 17.

[0037] According to the present invention, the balance wheel plate 26 includes a first elastic flexible portion 5 on which a first impact escapement fork 30 is mounted.

[0038] In addition, the balance wheel plate 26 includes a second elastic flexible portion 13 on which the second impact escapement fork 32 is mounted.

[0039] Each flexible part 5, 13 is arranged between two arms 17 on the rigid part 15 for use with the corresponding impact escapement forks 30, 32.

[0040] Each flexible section 5, 13 includes a translation platform 7, 21, on which impact escapement forks 30, 32 are suspended, and the translation platform includes flexible blades 9, 11.

[0041] The translation stages 7 and 21 include at least one flexible blade 9, which is arranged on either side of the impact escapement fork 30 and 32. Each flexible blade 9 connects a different arm 17 on the rigid portion 15 to the impact escapement fork 30 and 32. Preferably, when the flexible portions 5 and 13 are in the locked position, the flexible blade 9 is arranged substantially perpendicular to each impact escapement fork 30 and 32.

[0042] Preferably, each translation stage 7, 21 includes at least one pair of flexible blades 9, 11 arranged on each side of the escapement fork. The flexible blades 9, 11 are substantially parallel and arranged in the same plane as the balance wheel plate 26.

[0043] The impact escapement forks 30 and 32 are arranged radially and extend in the same plane as the translation stages 7 and 21. The impact escapement forks 30 and 32 are arranged perpendicular to each other.

[0044] Therefore, if the escape wheels 10 and 16 collide with the impact escape forks 30 and 32, the impact escape forks 30 and 32 will move radially along the rotation axis 24 of the balance wheel 20 due to the deflection of the flexible blades 9 and 11 on the translation platforms 7 and 21.

[0045] However, since the flexible blades 9 and 11 are arranged tangentially to the axis of rotation 24 of the balance wheel 20, these flexible parts 5 and 13 essentially prevent the impact escapement forks 30 and 32 from moving tangentially relative to the axis of rotation 24 of the balance wheel 20.

[0046] Therefore, the flexible parts 5 and 13 do not twist in this direction or only twist slightly, so that the direct impact of the impact escapement forks 30 and 32 given by the first escapement wheel 10 or the second escapement wheel 16 is transmitted to the balance wheel 20 with minimal energy loss.

[0047] Figure 6 A second embodiment of a balance wheel plate 29 with two flexible sections 5, 13 is shown, each flexible section including a translation platform 39 with a single flexible blade 41, on which each escapement fork stone 30, 32 is suspended.

[0048] The rigid part 43 is cross-shaped and includes a central opening 19, two lateral arms 37 (one on each side of the central opening 19), a rear axial arm 45 fitted with an elliptical portion, and a front axial arm 49.

[0049] Each individual flexible blade 41 connects the escapement fork stones 30, 32 to a lateral arm 37 on a different rigid portion 35. Each individual flexible blade 41 is connected at one end to one end of the lateral arm 37 and includes a movable free end 53 on the other side. The blade is oriented from the lateral arm 37 toward the front axial arm 49.

[0050] Escapement forks 30 and 32 are arranged in the middle of a single flexible blade 41.

[0051] The front axial arm 49 is equipped with a lateral stop 51 to block the free end 53 of the flexible blade 41 in order to prevent the flexible blade 41 from deflecting outward. However, the flexible blade can be twisted toward the central opening 19.

[0052] The flexible blade 41 can be twisted by moving its free end 53 closer to the central opening 19. Thus, in the event of an impact, the twisting of the single flexible blade 41 pushes the escapement forks 30, 32 backward toward the axis of rotation 24 of the balance wheel.

[0053] Figure 7 The third embodiment shows a balance wheel plate 25, which includes two escapement forks 30, 32 suspended by two flexible portions 5, 13. Each of the flexible portions 5, 13 includes a translation platform 39, which includes a pair of flexible blades 31 arranged on one side of the first impact escapement fork 30. The rigid portion 33 includes two lateral arms 47 extending on either side of the central opening 19, and a rear portion 35 including an elliptical portion 28.

[0054] Each escapement fork 30, 32 is held on one side by only two flexible blades 31 in the pair. The flexible blades 31 connect one end of the impact escapement fork 30, 32 to the free end of the lateral arm 47 at the other end of the different rigid parts 33, so that it can be moved by the deflection of the flexible blades 31.

[0055] Therefore, in the event of a radial impact, the escapement forks 30 and 32 are pushed backward toward the axis of rotation 24 of the balance wheel 20 by the twisting of the blades 31 in the pair of flexible blades.

[0056] Of course, the invention is not limited to the plate embodiments described with reference to the accompanying drawings, and variations are conceivable without departing from the scope of the invention. For example, in one particular embodiment, the balance wheel plate includes a single impact escapement fork configured to engage with an escapement comprising a single escape wheel. Such an escapement is, for example, a pawl escapement, a coaxial escapement, or a robin escapement, for which a single impact escapement fork is required on the plate.

Claims

1. A balance plate (25, 26, 29) configured to engage with a direct impact escapement (1), the balance plate (25, 26, 29) being fitted with a first impact escapement fork (30) designed to engage with an escape wheel (10) in the escapement (1), such that, during the impact phase, the escape wheel (10) directly impacts the balance plate (25, 26, 29) to actuate the balance wheel (20), the first impact escapement fork (30) being arranged radially to the axis of rotation (24) of the balance wheel (20), the balance plate (25, 26, 29) comprising a rigid portion (3) configured to be assembled to the balance wheel (20), characterized in that, The balance wheel plate (25, 26, 29) includes a first flexible portion (5) on which the impact escapement fork (30) is mounted, the first flexible portion (5) being configured such that the impact escapement fork (30) can move along the rotation axis (24) of the balance wheel (20) upon impact with the escapement wheel (10).

2. The balance wheel plate according to claim 1, characterized in that, The first flexible portion (5) includes a translation platform (7, 39) on which the impact escapement fork (30) is suspended. The translation platform (7) includes at least one flexible blade (9) configured to prevent the impact escapement fork (30) from moving substantially tangentially relative to the axis of rotation (24) of the balance wheel (20), particularly when the impact is delivered by the escapement wheel.

3. The balance wheel plate according to claim 2, characterized in that, The translation stage (7, 39) includes at least two flexible blades (9), each flexible blade being arranged on a different side of the impact escape fork (30), each flexible blade (9) connecting the impact escape fork (30) to the rigid part (3) so that it can be moved by the deflection of the flexible blade (9).

4. The balance wheel plate according to claim 2, characterized in that, The translation stage (7, 39) includes at least a pair of flexible blades (31) arranged on one side of the impact escape fork (30), each flexible blade (31) connecting the impact escape fork (30, 32) to the rigid part (3) so that it can be moved by the deflection of the flexible blade (9).

5. The balance wheel plate according to claim 2, characterized in that, The translation stage (7) includes two pairs of flexible blades (9, 11), each pair of flexible blades being arranged on different sides of the impact escape fork (30), and each flexible blade (31) connecting the impact escape fork (30, 32) to the rigid part (3) so that it can be moved by the deflection of the flexible blade (9).

6. The balance wheel plate according to any one of the preceding claims, characterized in that, The movement of the escapement fork (30) is substantially radial relative to the axis of rotation (24) of the balance wheel (20).

7. The balance wheel plate according to any one of the preceding claims, characterized in that, The balance wheel plate includes a second impact escapement fork (32) extending in the plane of the balance wheel plate (25, 26, 29).

8. The balance wheel plate according to claim 7, characterized in that, The balance wheel plate includes a second flexible portion (13) on which the second impact escapement fork (32) is mounted.

9. The balance wheel plate according to claim 8, characterized in that, The second flexible portion (13) is equipped with a second translation stage (21, 39), which includes at least one flexible blade (9) configured to prevent the second impact escapement fork (32) from moving substantially tangentially relative to the axis of rotation (24) of the balance wheel (20), especially when the impact is delivered by the escapement wheel.

10. The balance wheel plate according to claim 9, characterized in that, The second translation stage (21, 39) includes at least two flexible blades (31), each flexible blade being arranged on a different side or the same side of the second impact escape fork (30), each flexible blade (9) connecting the second impact escape fork (30) to the rigid part (3) so that it can be moved by the deflection of the flexible blade (9).

11. The balance wheel plate according to any one of the preceding claims, characterized in that, The rigid part (3) includes arms (15, 17) arranged perpendicularly to each other, and one or more impact escapement forks (30, 32) are arranged between the two arms (17) on the rigid part (3).

12. The balance wheel plate according to claim 11, characterized in that, The rigid part (3) includes an enlarged arm (15) fitted with a swing pin (28).

13. The balance wheel plate according to claim 11 or 12, characterized in that, The arms on the rigid part (3) form a cross.

14. A direct impact escapement mechanism (1), said escapement mechanism comprising at least one rotatable escape wheel (10), characterized in that, The direct impact escapement includes a balance wheel plate (25, 26, 29) according to any one of the preceding claims, the balance wheel plate (25, 26, 29) being rotatably movable along the rotation axis (24) of the balance wheel (20) such that, during the impact phase, the escape wheel (10) directly impacts the balance wheel plate (25, 26, 29) to actuate the balance wheel (20).

15. The direct impact escapement mechanism according to claim 14, characterized in that, The direct impact escapement is a natural escapement that includes a second escape wheel (16) and an escape fork (34).

16. A watch movement, characterized in that, The watch movement includes the direct impact escapement (1) as described in claim 14 or 15.

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