Movable parts with reduced inertia for timekeeping devices, especially for escapement mechanisms.

Abstract

The present invention provides a movable component for a timepiece that enables a traditional escapement mechanism to function efficiently, along with an adjustment mechanism fitted with a flexible guide. [Solution] One aspect of the present invention relates to a movable part (20, 30) for a timekeeping device, particularly for an escapement mechanism (50), which comprises a central hub (2) and a circumferential periphery gear row (14), the hub (2) being positioned inside the periphery gear row (14) and substantially in the same principal plane as the periphery gear row (14), and the movable part (20, 30) comprises a first group of blades (5, 15) connecting the hub (2) to the periphery gear row (4), the blades (5, 15) being distributed around the hub (2) in the principal plane, the blades (5, 15) being positioned substantially tangentially to the circumference of the hub (2), and the direction of the blades (5) forming an angle with respect to the tangential direction of the hub (2) within the range of -20° to +20°, preferably -10° to +10°, more preferably -5° to +5°.

Description

Technical Field

[0001] The present invention relates to a movable part for a timepiece with reduced inertia, particularly for a detent mechanism.

Background Art

[0002] In most mechanical portable timepieces (e.g., wristwatches, pocket watches), the energy required to rotate the hands (e.g., the minute hand and the hour hand) is stored in a barrel and consumed by a spring-type balance system. This is a combination of a flywheel called a balance and a spiral-shaped band spring called a balance spring.

[0003] The balance spring is attached at its inner end to a shaft that rotates with the balance. The balance spring is attached at its outer end to a balance spring stud attached to a stud holder, and this stud holder is attached to a fixed rod-shaped body (or cock).

[0004] The rotation of the balance is maintained by a detent mechanism including an anchor driven by a low-amplitude oscillatory motion, and the oscillations are counted. This mechanism includes two or three anchors that mesh with the teeth of a wheel. By meshing in this way, the wheel is made to perform a step-by-step rotational motion at a frequency determined by the oscillation frequency of the anchor. This anchor itself is set to the oscillation frequency of the spring-type balance.

[0005] In a traditional detent mechanism, this oscillation frequency is approximately 4 Hz, i.e., approximately 28,800 oscillations per hour (A / h). An excellent watchmaker aims to ensure that the spring-type balance oscillates isochronously and stably (i.e., the rate is kept constant).

[0006] Today, balance springs can be replaced by flexible guides that function as springs to form a virtual pivot. Thanks to flexible guides with virtual pivots, significant improvements can be made to the resonators of timepieces. The simplest is a cross-blade pivot, consisting of two guides containing intersecting straight blades. These two blades can be three-dimensional, extending into two different planes, or two-dimensional, extending into the same plane. In the latter case, the blades are soldered to each other at the intersection. However, there are also RCC (Remote Center Compliance) guides that contain non-intersecting straight blades. Such resonators are described in European patent documents EP14199039 and EP16155039.

[0007] However, such flexible guides must have a certain degree of rigidity to effectively guide the resonator, which results in a much smaller amplitude of the balance and a rotation angle of 10° to 40°. In contrast, with a balance spring, the rotation angle is 330°. Also, the balance vibrates at a much higher frequency than the balance attached to the balance spring.

[0008] As the amplitude of vibration decreases and the frequency increases, a new escapement mechanism configuration is being considered that functions in conjunction with a flexibly guided adjustment mechanism. For example, Swiss patent documents CH710524 and CH713150 describe specific escapement mechanisms for flexible guides.

[0009] However, these escapement mechanisms are inefficient and prone to stopping when subjected to shocks. Furthermore, they still occupy too much space, making them difficult to integrate into timekeeping movements.

[0010] The main reason why the performance of escapement mechanisms used with flexible guide resonators is limited is that losses occur because the last row, escape wheel, and anchor must be moved twice the frequency per second and then stopped.

[0011] Thus, the inertia of the anchor, the escape wheel, and the moving parts in the final row near the escape wheel are extremely important for achieving acceptable performance. [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] One of the objectives of the present invention is to provide a novel type of movable component that enables a traditional escapement mechanism to function efficiently, particularly in conjunction with an adjustment mechanism to which a flexible guide is attached. [Means for solving the problem]

[0013] Therefore, the present invention relates particularly to a movable part for a timekeeping device, for an escapement mechanism. The aforementioned movable part for the timekeeping device includes a central hub and a circumferential periphery of teeth, The hub is positioned inside the peripheral dentition and in substantially the same principal plane as the peripheral dentition. The movable part includes a first group of blades that connect the hub to the peripheral tooth row, The blades are distributed around the hub within the main plane.

[0014] The present invention relates to the arrangement of the blade substantially tangentially with respect to the circumference of the hub, The blade's orientation is groundbreaking in that it forms an angle with respect to the tangential direction of the hub that is within the range of -20° to +20°, preferably -10° to +10°, and more preferably -5° to +5°.

[0015] This blade configuration improves the rigidity of the moving parts, thereby avoiding the risk of the blades buckling, especially when these moving parts mesh with other moving parts in the gear system. It also eliminates the need for many blades, as was the case with the wheels of early spoked bicycles where the spokes were arranged radially to the hub.

[0016] In fact, by selecting the appropriate direction of rotation, the blade is effectively pulled longitudinally, reducing shear stress.

[0017] This invention significantly reduces the inertia of the moving parts because the blade is much lighter and thinner than the arm that connects the hub to the peripheral teeth in conventional moving parts.

[0018] In a particular embodiment of the present invention, the rotational inertia of the movable part for the timekeeping device is 5 mg·mm 2 Less than 3 mg / mm 2 Less than, more preferably 2 mg·mm 2 It is less than.

[0019] In a particular embodiment of the present invention, the thickness e of the blade is e ≤ h / 3, preferably e ≤ h / 5, Here, h is the height of the blade.

[0020] In a particular embodiment of the present invention, each blade of the first group of blades is arranged to face a direction that forms an angle α = 2π / N with the direction of the preceding blade, Here, N is the number of blades in the first group.

[0021] In a particular embodiment of the present invention, the first group of blades are evenly distributed around the hub.

[0022] In a particular embodiment of the present invention, the blade is straight.

[0023] In a particular embodiment of the present invention, the movable part for the timepiece includes a second group of blades connecting the hub to the peripheral tooth row in the main plane, Thereby forming an array of blades that intersects the first group of blades.

[0024] In a particular embodiment of the present invention, the second group of blades is arranged substantially tangentially with respect to the circumference of the hub.

[0025] In a particular embodiment of the present invention, the array forms a star-shaped structure.

[0026] In a particular embodiment of the present invention, the second group of blades is in a bent shape.

[0027] In a particular embodiment of the present invention, the peripheral tooth row has a plurality of teeth, Each of those teeth is arranged at the junction of the free end of the first group of blades and the free end of the second group of blades.

[0028] In a particular embodiment of the present invention, the peripheral tooth row has an annular rim on which a plurality of teeth are arranged.

[0029] In a particular embodiment of the present invention, the annular rim is hollow.

[0030] The present invention further relates to an escapement mechanism including an anchor and a movable part for a timepiece with reduced inertia, such as a gang wheel, and this escapement mechanism is configured to engage with an adjustment mechanism in a timepiece movement.

[0031] In a particular embodiment of the present invention, the adjustment mechanism includes a flexible guide.

[0032] In a particular embodiment of the present invention, the escapement mechanism includes a second movable part with reduced inertia as an intermediate movable part between the seconds wheel and the gang wheel, and this second movable part meshes with the first movable part.

[0033] The present invention further relates to a timekeeping movement including such an escapement mechanism.

[0034] Further understanding of other features and advantages of the present invention can be gained by reading the following description of specific embodiments of the present invention while referring to the attached drawings. These are given merely as examples. [Brief explanation of the drawing]

[0035] [Figure 1] A schematic top view of a movable part for a timekeeping device according to the first embodiment of the present invention is shown. [Figure 2] A schematic top view of a movable part for a timekeeping device according to a second embodiment of the present invention is shown. [Figure 3] Figure 2 schematically shows a perspective view of a second embodiment of the movable component for the timekeeping device. [Figure 4] Figure 2 schematically shows a top view of a variant of the second embodiment of the movable component for the timekeeping device. [Figure 5] A schematic top view of a movable part for a timekeeping device according to a third embodiment of the present invention is shown. [Figure 6] A schematic top view of an escapement mechanism including a movable part according to a third embodiment of the present invention is shown. [Figure 7] Figure 6 shows a schematic, enlarged top view of a portion of the escapement mechanism. [Figure 8] A schematic top view of the escapement mechanism, including two movable parts, according to the present invention is shown. [Figure 9] Figure 8 shows a schematic top view of the adjustment mechanism related to the escapement mechanism. [Figure 10] Figure 9 schematically shows a cross-sectional view of the adjustment mechanism related to the escapement mechanism, without the flexible guide. [Modes for carrying out the invention]

[0036] Figures 1-5 show different embodiments of the timekeeping movable parts 1, 10, 20, and 30, particularly for the escapement mechanism 50.

[0037] Each movable part 1, 10, 20, and 30 includes a hub 2 and a periphery tooth row 4. The hub 2 is positioned inside the periphery tooth row 4, preferably in substantially the same principal plane as the periphery tooth row 4.

[0038] In Figures 1-3, the peripheral dentition 4 includes annular rims 9 and 19 with teeth 8 and 18, and in the embodiment shown in Figure 4, the peripheral dentition 14 has a rim 19 and hollow teeth 18. The peripheral dentition 4 is composed of two overlapping sine waves.

[0039] In these embodiments, the movable parts 1, 10, 20, and 30 further include a shaft 7 and a pinion 3, the shaft 7 being configured to pass through the hub 2, and the pinion 3 being attached to the shaft 7 above the hub 2.

[0040] In Figure 1, the movable component 1 for the timekeeping device includes a first group of blades 5 that connect the hub 2 to the peripheral tooth row 4.

[0041] The blades 5 of the first group are evenly distributed around the hub 2 in the main plane. Preferably, the blades 5 of the first group are straight. Alternatively, the blades 5 of the first group are curved.

[0042] According to the present invention, the blades 5 of the first group are arranged substantially tangentially with respect to the hub 2. For example, the orientation of the blades 5 forms an angle with respect to this tangential direction that is within the range of -20° to +20°, preferably -10° to +10°, and more preferably -5° to +5°.

[0043] The blades 5 of the first group are arranged to face in a direction that forms an angle α = ±2π / N with respect to the direction of the previous or next blade 5, where N is the number of blades 5 in the first group. For example, in Figure 1, the movable part 1 for the timer includes 10 blades 5. Each blade 5 is arranged to face in a direction that forms an angle of 36° with respect to the direction of the next blade 5 or the direction of the previous blade 5. The blades 5 are arranged in a clockwise direction.

[0044] In the embodiments shown in Figures 2-5, the movable parts 10 and 20 include a second group of blades 6 that connect the hub 2 to the peripheral tooth row 4 in the main plane.

[0045] The blades 6 of the second group are arranged in the same main plane. Therefore, the blades 5 of the first group and the blades 6 of the second group form an array of intersecting blades.

[0046] In the embodiments shown in Figures 2, 3, and 4, the blades 6 of the second group are arranged substantially tangentially to the hub 3, similar to the blades 5 of the first group, and are the same in nature as the blades 5 of the first group, but are arranged counterclockwise.

[0047] The blades 5 of the first group and the blades 6 of the second group are paired and joined at the periphery of the dentition 4. This forms a star-shaped array of blades 5 and 6.

[0048] Figure 5 shows another movable part 30 for a timekeeping device that is particularly suitable for the escapement mechanism 50 shown in Figures 6-8.

[0049] In this embodiment, the movable part 30 includes a hub 3 and two groups of blades 5 and 16, but the peripheral tooth row 24 does not have an annular rim. The peripheral tooth row 24 has teeth positioned at the junction between the free end of the first group of blades 5 and the free end of the second group of blades 16. The second group of blades 16 is also curved.

[0050] Preferably, in order to minimize the inertia of the movable parts 1, 10, 20, and 30, the thickness e of each blade 5, 6, and 16 corresponds to the following formula: e ≤ h / 3, Here, h is the height of the blade, and preferably e ≤ h / 5.

[0051] With these configurations and parameters, the rotational inertia of the movable parts is less than 5 mg·mm, preferably less than 3 mg·mm, and more preferably less than 2 mg·mm.

[0052] Preferably, the movable parts 1, 10, 20, and 30 for the timekeeping device are made of the same material, such as NiP or silicon, and obtained by deep photolithography methods such as UV-LIGA or DRIE.

[0053] For example, these moving parts with reduced inertia are used in the escapement mechanisms of timekeeping movements.

[0054] In Figures 6-8, the escapement mechanism 50 includes a first clock wheel 30, which is an escape movable part, and a lever 21, according to the configuration of Figure 5.

[0055] Ankle 21 is fitted with two arms 11 and 12, the two ends of these arms 11 and 12 forming two anchor stones that mesh with the teeth 18 of the first movable part 30.

[0056] The arms 11 and 12 of the ankle 21 engage with the first movable part 30, which has reduced inertia, and interact alternately with the teeth 18 of the first movable part 30 to adjust the rate.

[0057] The ankle 21 further has a longitudinal portion 14 that extends laterally, at which a fork 22 is provided, and the ellipse 23 is linked with the inertial element 26.

[0058] To further reduce inertia and improve the responsiveness of the escapement mechanism 50, the escapement mechanism 50 further includes a second movable part 20, which meshes with the first movable part 30, such as a second movable wheel. In this example, the second timekeeping movable part 20 corresponds to the embodiment shown in Figure 4.

[0059] The teeth 14 of the second movable part 20 mesh with the pinion 3 of the first movable part 30.

[0060] In Figures 9 and 10, such an inertia-reduced escapement mechanism 50 is associated with an adjustment mechanism 60. The adjustment mechanism 60 includes a balance 35 and an elastic means 32 for returning the balance 35 to its original position.

[0061] The balance 35 has a bone-like shape with a longitudinal portion 36 and a transverse portion 37, the transverse portion 37 being in the form of an arc at each of the two ends of the longitudinal portion 36. The balance 35 further includes a stopper mounted in the center of the longitudinal portion 36 and concentric with a virtual axis of rotation, and a screw 39 located in the transverse portion 37 for setting the balance's inertia.

[0062] The balance 35 is attached to the elastic return mechanism 32 and configured to perform rotational oscillating motion around a virtual center of rotation. The elastic return mechanism 32 is directly connected to the balance 35.

[0063] The elastic return mechanism 32 consists of a system of flexible blades 37, in which a series of intersecting pairs of two flexible blades 37 are arranged in series to form a double pivot, thereby improving the rotation angle of the balance 35.

[0064] Below the balance 35, the ellipse 23 extends from the longitudinal portion 36 and engages with the fork 22 on the ankle 21. The ellipse is integrally attached to the balance 35.

[0065] Such adjustment mechanism 60 has a high frequency. Therefore, the inertia-reduced escapement mechanism 50 according to the present invention can function optimally at this frequency.

[0066] Naturally, the present invention is not limited to the embodiments described with reference to the drawings, and variations can be considered without departing from the scope of the present invention. [Explanation of Symbols]

[0067] 1, 10, 20, 30 moving parts 2 hubs 4, 14, 24 Peripheral dentition 5, 15, 6, 16 blades 8, 18, 28 teeth 9, 19 ring rim 20 Moving parts 21 Uncle 24 Peripheral dentition 50 Escapement mechanism

Claims

1. Movable parts (1, 10, 20, 30) for a timekeeping device, particularly for an escapement mechanism (50), The aforementioned movable parts (1, 10, 20, 30) include a central hub (2) and a circumferential periphery of teeth (4, 14, 24), The hub (2) is positioned inside the peripheral dentition (4, 14, 24) and in substantially the same main plane as the peripheral dentition (4, 14, 24). The movable parts (1, 10, 20, 30) include a first group of blades (5, 15) that connect the hub (2) to the peripheral tooth row (4), The blades (5, 15) are distributed around the hub (2) within the main plane. The blades (5, 15) are arranged substantially tangentially with respect to the circumference of the hub (2). The direction of the blade (5) forms an angle within the range of -20° to +20°, preferably -10° to +10°, and more preferably -5° to +5°, with respect to the tangential direction of the hub (2). Movable parts for timekeeping devices.

2. The rotational inertia of the aforementioned movable part is 5 mg·mm ２ Less than 3 mg / mm², preferably 3 mg / mm² ２ Less than 2 mg / mm², more preferably 2 mg / mm² ２ Less than, A movable part for a timekeeping device as described in claim 1.

3. The thickness e of the blades (5, 15) is e ≤ h / 3, preferably e ≤ h / 5, And, Here, h is the height of the blades (5, 15). A movable part for a timekeeping device as described in claim 1.

4. Each blade (5, 15) of the first group of blades is positioned to face in a direction that forms an angle α = 2π / N with the direction of the preceding blade. Here, N is the number of blades (5, 15) in the first group. A movable part for a timekeeping device as described in claim 1.

5. The blades (5, 15) of the first group are evenly distributed around the hub (2). A movable part for a timekeeping device as described in claim 1.

6. The blades (5, 15) of the first group are straight. A movable part for a timekeeping device as described in claim 1.

7. The hub (2) includes a second group of blades (6, 16) that connect to the peripheral teeth (4, 14, 24) in the main plane, This forms an array of blades (5, 15, 6, 16) that intersect with the blades (5, 15) of the first group. A movable part for a timekeeping device as described in claim 1.

8. The blades (6, 16) of the second group are arranged substantially tangentially to the hub (2). The movable part for a timekeeping device according to claim 7.

9. The array forms a star-shaped structure. The movable part for a timekeeping device according to claim 7.

10. The blades (16) of the second group are curved. The movable part for a timekeeping device according to claim 7.

11. The aforementioned peripheral dentition (24) has multiple teeth (28), Each of these teeth (28) is positioned at the joint between the free end of the first group of blades (15) and the free end of the second group of blades (16). The movable part for a timekeeping device according to claim 7.

12. The aforementioned peripheral dentition (4, 14) has an annular rim (9, 19) on which multiple teeth (8, 18) are arranged. A movable part for a timekeeping device as described in claim 1.

13. The aforementioned annular rim (19) is hollow. The movable part for a timekeeping device according to claim 12.

14. An escapement mechanism (50) comprising an anchor (21) and a first movable part, which is the movable part (30) described in claim 1, The first movable part (30) forms the escape wheel of the escapement mechanism (50). Escapement mechanism (50).

15. The second movable part is a movable part (20) according to any one of claims 1 to 13, The second movable part (20) engages with the first movable part (30) and functions as an intermediate movable part between the second movable part and the escape movable part. The escapement mechanism according to claim 14.

16. A timekeeping movement comprising the escapement mechanism (50) described in claim 14.

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