Pointer setting device for timepiece movement

Abstract

The invention relates to a hand setting device (10) for a watch, the hand setting device (10) comprising a winding stem (11) configured to occupy a hand setting position in which it engages with a hand setting gear train (20) kinematically connected to a time display (30) and a 24 hour wheel (31), the winding stem (11) being configured to take up a hand setting position in which it engages with a hand setting gear train (20), the hand setting gear train (20) being kinematically connected to the time display (30) and the 24 hour wheel (31), the 24-hour wheel (31) is engaged with a barrel (40) providing energy to display a time value, the barrel (40) comprising a pawl mechanism (41) configured to allow the barrel (40) to rotate more than one turn when the winding stem (11) is rotated in a first direction and to allow the barrel (40) to rotate more than one turn when the winding stem (11) is rotated in a second direction. The pawl mechanism limits the rotation of the barrel (40) to an angular amplitude corresponding to less than one turn.

Description

Technical Field

[0001] The present invention relates to the field of watchmaking, and more particularly to a device for setting the hands of a watch. Background Art

[0002] The device for setting the hands of a watch is integrated into the watch movement and is well-known to those skilled in the art.

[0003] For example, a commonly used device for setting the hands includes one or more intermediate wheels that kinematically connect the winding stem, which is intended to be operated by the user, to a minute wheel train that is connected to the time display.

[0004] When the watch movement incorporates one or more complications, the device for setting the hands can be designed to comply with multiple constraints.

[0005] The present invention is suitable for this background. Specifically, the present invention aims to eliminate any risk of damaging the watch movement when setting the hands of the watch. Summary of the Invention

[0006] To this end, the present invention relates to a device for setting the hands of a watch, said device for setting the hands comprising a winding stem configured to occupy a hand-setting position in which the winding stem engages with a hand-setting gear train that is kinematically connected to a time display and a 24-hour wheel. The 24-hour wheel engages with a barrel that includes a mainspring that provides the energy for displaying the time value, and the barrel includes a ratchet mechanism configured such that when the winding stem is rotated in a first direction, the ratchet mechanism allows the barrel to rotate more than one full turn, while when the winding stem is rotated in a second direction, the ratchet mechanism limits the rotation of the barrel to an angular amplitude corresponding to less than one full turn.

[0007] In a particular embodiment, the present invention may further include one or more of the following features, which may be considered individually or in any technically feasible combination.

[0008] In a particular embodiment, the hand-setting gear train includes a friction wheel train configured such that when the winding stem is rotated in the second direction and the barrel is forced into a stop position by the ratchet mechanism, the friction wheel train prevents movement from being transmitted from the winding stem to the 24-hour wheel.

[0009] In a particular embodiment, the hand-setting gear train includes a transmission wheel train kinematically interposed between the friction wheel train and the time display.

[0010] In a particular embodiment, the transmission wheel train is in meshing relationship with the 24-hour wheel and the hour wheel.

[0011] In a particular embodiment, the barrel is configured such that when the winding arbor is rotated in a second direction and when the ratchet mechanism prevents the barrel from rotating, the mainspring is preloaded.

[0012] In a particular embodiment, the ratchet mechanism includes a projection and a lever. The projection is eccentrically arranged on the barrel and extends parallel to the axis of rotation of the barrel. The lever is intended to cooperate with the projection such that when the winding arbor is rotated in a first direction, the projection pivots the lever, and when the winding arbor is rotated in a second direction, the projection abuts against the lever.

[0013] In a particular embodiment, the friction wheel pair includes two wheels. Each wheel is arranged at one end of a mandrel including a platform. One of the wheels, referred to as the "first wheel", has a pipe fitting that applies a deforming force to an elastic member, thereby forcing the elastic member to apply a pressure to a flange such that the flange applies a clamping force to the other wheel, referred to as the "second wheel", in combination with the platform.

[0014] In a particular embodiment, the elastic member consists of a part that is straight in the rest state and bent in the stressed state.

[0015] In a particular embodiment, the elastic member is formed by a disk having radial ridges on its periphery. These ridges are intended to abut against the flange in order to rigidly attach the flange to the elastic member such that the flange rotates integrally with the elastic member. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features and advantages of the present invention will become apparent from the following detailed description given by way of example and not limitation with reference to the accompanying drawings, in which:

[0017] - Figure 1 A perspective view of the kinematic chain of a pointer setting device according to a preferred exemplary embodiment of the present invention is shown;

[0018] - Figure 2 Shows Figure 1 A cross-sectional view of the friction wheel pair of the pointer setting device shown;

[0019] - Figure 3 Shows Figure 1 A perspective bottom view of the kinematic chain of the pointer setting device shown.

[0020] It should be noted that, for clarity, these drawings are not necessarily to scale. DETAILED DESCRIPTION

[0021] Figure 1There is shown a hand setting device 10 for a watch, which is intended to be integrated into the watch movement. In the preferred exemplary embodiment of the invention shown in the figures and described herein, the hand setting device 10 is capable of setting the time and date of the watch.

[0022] The hand setting device 10 includes a winding stem 11, which a watch user is intended to operate in order to set the time and optionally the date. Specifically, the winding stem 11 is configured to assume a hand setting position, in which it engages with a hand setting gear train 20, which is kinematically connected to a time display 30 and a 24-hour wheel 31. In this preferred exemplary embodiment of the invention, the time display 30 consists of an hour hand and a minute hand.

[0023] The 24-hour wheel 31 meshes with a barrel 40, which includes a mainspring 40 for providing the energy required to display the time value (in particular the date). Specifically, the 24-hour wheel 31 meshes with a ratchet 401 of the barrel 40. The barrel 40 may be as described in European patent EP3540524. The watch movement may include another barrel for providing the energy required to rotate the time display 30.

[0024] The barrel 40 includes a pawl mechanism 41, which is configured to: when the winding stem 11 is rotated in a first direction, allow the barrel 40 to rotate over an angular amplitude corresponding to more than one turn, while when the winding stem 11 is rotated in a second direction, limit the rotation of the barrel 40 to an angular amplitude corresponding to less than one turn.

[0025] Due to these features of the invention, the user can set the hands by moving the time display 30 in two rotational directions while avoiding completely unwinding the mainspring 40. More specifically, setting the hands in the first direction has the effect of winding the mainspring 40. Thus, setting the hands in the second direction unwinds the mainspring 40 until the pawl mechanism 41 locks it to prevent rotation. It should be noted that when the pawl mechanism 41 locks the barrel 40 to prevent rotation, the time display 30 is also immobilized.

[0026] In this preferred exemplary embodiment of the invention, the pawl mechanism 41 includes a projection 410, which is formed, for example, by a pin, is eccentrically arranged on the barrel 40, and extends parallel to the axis of rotation of the barrel 40. Thus, when the barrel 40 rotates, the projection 410 is driven along a circular path centered around the axis of rotation of the barrel 40.

[0027] The ratchet mechanism 41 further includes a rod 411, one end of which is arranged in the path of the protrusion 410 such that when the barrel 40 rotates, the protrusion 410 cooperates with the rod 411. More specifically, when the winding arbor 11 is rotated in the first direction, the protrusion 410 pivots the rod 411, and when the winding arbor 11 is rotated in the second direction, the protrusion 410 abuts against the rod 411. The latter case is shown in Figure 1 as shown.

[0028] When the barrel 40 is locked by the ratchet mechanism 41 and cannot rotate, that is, when the protrusion 410 is arranged to abut against the rod 411, the friction wheel pair 50 advantageously makes it possible to avoid any damage to the watch movement, in particular to the components of the motion chain of the pointer setting device 10. Specifically, such damage is likely to occur if the winding arbor 11 is rotatably driven in the second direction when the barrel 40 is locked and cannot rotate.

[0029] As Figure 1 shown, the friction wheel pair 50 is arranged in the pointer setting gear train 20 and is configured to prevent the transmission of motion from the winding arbor 11 to the 24-hour wheel 31 when the winding arbor 11 is rotated in the second direction and when the barrel 40 is forced into the stop position by the ratchet mechanism 41.

[0030] In a preferred exemplary embodiment of the present invention, the friction wheel pair 50 (visible in the cross-sectional view of Figure 2 ) includes a driven wheel 51 connected to one end of a spindle 52 without any degree of freedom. The spindle 52 includes a platform 53 at its other end. The driven wheel 51 has a pipe fitting 510 extending towards the platform 53. The platform 53 preferably has an annular shoulder 530 in which a driving wheel 54 is received, and the driving wheel 54 is mounted to rotate freely relative to the platform 53. The driving wheel 54 is in meshing relationship with one of the intermediate wheels 21, as Figure 1 shown.

[0031] The friction wheel pair 50 further includes a flange 55 which is non-rotatably fixed relative to the spindle 52 and includes an upper annular lip 550 facing the driving wheel 54 and resting on the driving wheel 54, and a lower annular lip 551 extending axially and facing the driven wheel 51. An elastic member 56 is interposed between the flange 55 and the driven wheel 51, the spindle 52 extends through the elastic member 56, and the elastic member 56 is stressed by the lower annular lip 551 and the pipe fitting 510.

[0032] In this preferred exemplary embodiment of the invention, the elastic member 56 is composed of a component that is straight in the rest state and bent in the stressed state. The elastic member is formed, for example, by a disk having radial protrusions on its periphery, the protrusions being intended to bear against the lower annular lip 551. The fact that the elastic member 56 is formed by a component that is straight in the rest state makes it particularly easier to manufacture and ensures compliance with manufacturing tolerances. Advantageously, the protrusions allow a uniform distribution of mechanical stresses. To facilitate the assembly of the friction wheel pair 50, the pin 57 can be engaged in corresponding holes in the platform 53 and the flange 55 to ensure that they rotate together.

[0033] The elastic member 56 is stressed so as to exert a pressure on the lower annular lip 551 of the flange 55, whereby the driving wheel 54 is clamped between the upper annular lip 550 of the flange 55 and the platform 53. Thus, the driving wheel 54 transmits a rotational movement to the driven wheel 51 until a certain frictional torque is reached, beyond which the upper annular lip 550 and the platform 53 will slide relative to the driving wheel 54. Such a frictional torque is generated when the barrel 40 is locked against rotation by the ratchet mechanism 41 and when the winding stem 11 is rotated in the second direction.

[0034] By stressing the elastic member 56, in particular a disk having radial protrusions, the frictional torque can be controlled, and it is advantageous for the manufacture and assembly of the friction wheel pair 50.

[0035] Furthermore, the interface surfaces of the platform 53 and the driving wheel 54 advantageously have inclined sections, and the interface surface of the lower annular lip 551 of the elastic member 56 that is intended to receive the abutment also has an inclined section. This special arrangement of the surfaces allows better control of the frictional torque.

[0036] As Figure 1 and 3 shown, the pointer setting gear train 20 includes a plurality of intermediate wheels 21, thereby allowing the winding stem 11 and the friction wheel pair 50 to be kinematically interconnected. The pointer setting gear train 20 also includes a transmission wheel pair 60, which is kinematically interposed between the friction wheel pair 50 and the time display 30. The transmission wheel pair 60 is, for example, in meshing relationship with the driven wheel 51 by means of an intermediate wheel, as Figure 1 shown.

[0037] As Figure 3 shown, the transmission wheel pair 60 is in meshing relationship with the 24-hour wheel 31, the minute shaft 32, and the hour wheel 33 via a 24-hour pinion 61, a minute wheel 62, and a minute pinion 63, respectively.

[0038] The barrel 40 is configured such that when the winding arbor 11 is rotated in the second direction and when the ratchet mechanism 41 prevents the barrel 40 from rotating, the mainspring 40 is pre-loaded. This feature prevents the mainspring 40 from being fully unwound, thus storing a certain amount of energy in the barrel 40. Specifically, this pre-loading enables the angular position of the barrel 40 to be controlled.

[0039] More generally, it should be noted that the implementations and embodiments considered above are described as non-limiting examples, and thus other alternatives are also feasible.

[0040] Specifically, in other exemplary embodiments of the present invention, the driven wheel 51 and the driving wheel 54 can be interchanged without changing the operation of the friction wheel pair 50. In other words, herein and Figure 2 the wheel referred to as the "driven wheel 51" can be the driving wheel, and the wheel referred to as the "driving wheel 54" can be the driven wheel.

Claims

1. A pointer setting device (10) for a watch, characterized in that: The hand setting device (10) comprises a winding stem (11) configured to occupy a hand setting position, in which the winding stem is engaged with a hand setting gear train (20), the hand setting gear train (20) being kinematically connected to a time display (30) and a 24-hour wheel (31), the 24-hour wheel (31) being engaged with a barrel (40), the barrel (40) comprising a spring (40) providing energy for displaying a time value, the barrel (40) comprising a pawl mechanism (41), the pawl mechanism being configured such that when the winding stem (11) is rotated in a first direction, the pawl mechanism allows the barrel (40) to rotate more than one revolution, and when the winding stem (11) is rotated in a second direction, the pawl mechanism limits the rotation of the barrel (40) to an angular amplitude corresponding to less than one revolution.

2. The pointer setting device according to claim 1, wherein: The hand setting gear train (20) comprises a friction wheel set (50) configured to prevent the transmission of motion from the winding stem (11) to the 24 hour wheel (31) when the winding stem (11) is rotated in the second direction and when the barrel (40) is forced into a stop position by the pawl mechanism (41).

3. The pointer setting device according to claim 2, wherein: The hand setting gear train (20) comprises a transmission wheel set (60) which is kinematically interposed between the friction wheel set (50) and the time display (30).

4. The pointer setting device according to claim 3, wherein: The transmission wheel set (60) is in meshing relationship with the 24-hour wheel (31) and the hour wheel (33).

5. The pointer setting device according to any one of claims 1 to 4, wherein: The mainspring barrel (40) is configured such that when the winding stem (11) is rotated in a second direction and when the pawl mechanism (41) prevents the mainspring barrel (40) from rotating, the mainspring (40) is preloaded.

6. The pointer setting device according to any one of claims 1 to 5, wherein: The pawl mechanism (41) includes a protrusion (410) and a rod (411), wherein the protrusion (410) is eccentrically arranged on the barrel (40) and extends parallel to the rotation axis of the barrel (40), and the rod (411) is used to cooperate with the protrusion (410) so that when the winding stem (11) is rotated in a first direction, the protrusion causes the rod (411) to pivot, and when the winding stem (11) is rotated in a second direction, the protrusion abuts against the rod (411).

7. The pointer setting device according to any one of claims 2 to 4, wherein: The friction wheel pair (50) comprises two wheels (51, 54), each wheel being arranged at one end of a spindle (52), the spindle (52) comprising a platform (53), wherein one of the wheels (51, 54) is referred to as the first wheel (51), the first wheel (51) having a tube (510), the tube applying a deformation force to an elastic member (56) to force the elastic member (56) to apply pressure to a flange (55), so that the flange (55) in combination with the platform (53) applies a clamping force to another wheel, referred to as the second wheel (54).

8. The pointer setting device according to claim 7, wherein: The elastic member (56) consists of a part which is straight in a resting state and curved in a stressed state.

9. The pointer setting device according to claim 8, wherein: The elastic member (56) is formed by a disk having radial lobes at its periphery, the lobes being intended to abut against the flange (55) in order to rigidly attach the flange to the elastic member (56) so that the flange rotates integrally with the elastic member.

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