Hand setting device for watch movements

Abstract

To eliminate any risk of damage to a horological movement when watch hands are set.SOLUTION: A hand-setting device 10 for a watch includes a winding stem 11. The winding stem 11 is configured to occupy a hand-setting position in which the winding stem 11 is engaged with a hand-setting gear train 20 kinematically connected to a time display 30 and a 24-hour wheel 31. The 24-hour wheel 31 is engaged with a barrel 40 including a main spring 40 for supplying energy for displaying a time value, the barrel 40 includes a click mechanism 41, and the click mechanism 41 is configured to permit rotation of the barrel 40 through more than one revolution when the winding stem 11 is rotated in a first direction, and to limit rotation of the barrel 40 to an angular amplitude corresponding to less than one revolution when the winding stem 11 is rotated in a second direction.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Wristwatch hand setting devices are incorporated into watch movements and are well known to those skilled in the art.

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

[0004] When the watch movement includes one or more watch complications, the hand setting device can be designed to comply with a certain number of constraints.

[0005] The present invention fits within this context. More particularly, the present invention aims to eliminate the risk of damage to the watch movement when the wristwatch hands are set.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] To this end, the present invention relates to a wristwatch hand setting device, the device including a winding stem configured to occupy a hand setting position that meshes with a hand setting gear train kinematically connected to a time indicator and a 24-hour wheel. The 24-hour wheel engages with a barrel containing a mainspring that provides energy for displaying the time value. The barrel includes a click mechanism, which is configured to allow rotation of the barrel more than one revolution when the winding stem rotates in a first direction, and to limit the rotation of the barrel to an angular amplitude corresponding to less than one revolution when the winding stem rotates in a second direction.

[0008] In certain embodiments, the present invention may further include one or more of the following features. These features should be considered individually or in any technically possible combination.

[0009] In a particular embodiment, the needle setting gear train includes a set of friction wheels configured to prevent motion from being transmitted from the winding stem to the 24-hour wheel when the winding stem rotates in a second direction and the mainspring barrel is forced to a stop position by a click mechanism.

[0010] In certain embodiments, the needle setting gear train includes a transmission wheelset kinematically interposed between a friction wheelset and a time indicator.

[0011] In a particular embodiment, the transmission wheelset is in a meshing relationship with the 24-hour wheel and the hour wheel.

[0012] In a particular embodiment, the barrel is configured such that the mainspring receives pre-energization when the winding stem rotates in a second direction and the click mechanism prevents the barrel from rotating.

[0013] In a particular embodiment, the click mechanism includes a projection eccentrically positioned on the barrel and extending parallel to the axis of rotation of the barrel, and a lever intended to cooperate with the projection, the lever swinging when the winding stem rotates in a first direction and contacting the lever when the winding stem rotates in a second direction.

[0014] In a particular embodiment, the friction wheel set includes two wheels, each wheel positioned at one end of a spindle including a platform, and one of the wheels, referred to as the "first wheel," has a pipe that applies a deformable force to an elastic member, the elastic member which applies pressure to a flange, the flange which, in combination with the platform, applies a clamping force to the other wheel, referred to as the "second wheel."

[0015] In a particular embodiment, the elastic member is composed of a component that is flat in a static state and curved when stressed.

[0016] In a particular embodiment, the elastic member is formed by a disc having a plurality of radial lobes on its periphery, the lobes being intended to abut against a flange. As a result, the flange is rigidly attached to the elastic member, and they rotate together as a single unit. [Brief explanation of the drawing]

[0017] Other features and advantages of the present invention will become apparent from the following detailed description, which is given by illustration with reference to the accompanying drawings and is not limiting.

[0018] [Figure 1] A perspective view of the kinematic chain of a needle setting device according to a preferred exemplary embodiment of the present invention is shown. [Figure 2] Figure 1 shows a cross-sectional view of the friction wheel set of the needle setting device. [Figure 3] Figure 1 is a perspective bottom view of the kinematic chain of the needle setting device shown.

[0019] Please note that the diagrams are not necessarily drawn to scale for clarity. [Modes for carrying out the invention]

[0020] Figure 1 shows a hand setting device 10 for a wristwatch. This device is intended to be incorporated into the watch movement of the wristwatch. In the preferred exemplary embodiment of the invention shown in the figure and described in the text, the hand setting device 10 can set both the time and date of the wristwatch.

[0021] The hand setting device 10 includes a winding stem 11 that is operated by the user of the wristwatch to set the time and optionally the date. Specifically, the winding stem 11 is configured to occupy a hand setting position that meshes with a hand setting gear train 20 kinematically connected to a time display 30 and a 24-hour wheel 31. The time display 30, in the preferred exemplary embodiment of the invention, is composed of an hour hand and a minute hand.

[0022] The 24-hour wheel 31 meshes with a barrel 40 that includes a mainspring 40 intended to supply the energy required to display time values, specifically the date. Specifically, the 24-hour wheel 31 meshes with a ratchet 401 of the barrel 40. The barrel 40 may be the one described in Patent Document 1. The watch movement may include other barrels intended to supply the energy required to rotate the time display 30.

[0023] The barrel 40 includes a click mechanism 41. The click mechanism 41 is configured to allow the barrel 40 to rotate over an angular amplitude corresponding to a rotation exceeding one revolution when the winding stem 11 rotates in a first direction, and to limit the rotation of the barrel 40 to an angular amplitude corresponding to a rotation less than one revolution when the winding stem 11 rotates in a second direction.

[0024] Due to the features of the present invention, while avoiding completely releasing the main spring 40, the user can set the hands by moving the time display 30 in both rotational directions. More specifically, setting the hands in the first direction has the effect of winding up the main spring 40. That is, the main spring 40 is released until the click mechanism 41 locks it so that the main spring 40 does not rotate. It should be noted that when the click mechanism 41 locks the casket 40 so that it does not rotate, the time display 30 also becomes immobile.

[0025] In a preferred exemplary embodiment of the present invention, the click mechanism 41 includes, for example, a protrusion 410 formed by a pin. The protrusion 410 is eccentrically arranged on the casket 40 and extends parallel to the rotation axis of the casket 40. That is, when the casket 40 rotates, the protrusion 410 is driven along a circular orbit around the rotation axis of the casket 40.

[0026] The click mechanism 41 further includes a lever 411. Since one end of the lever 411 is arranged in the path of the protrusion 410, when the casket 40 rotates, the protrusion 410 cooperates with the lever 411. More specifically, the protrusion 410 swings the lever 411 when the winding drum 11 rotates in the first direction and abuts against the lever 411 when the winding drum 11 rotates in the second direction. The latter case is shown in FIG. 1.

[0027] When the casket 40 is locked by the click mechanism 41 so that it does not rotate, that is, when the protrusion 410 is arranged to abut against the lever 411, the friction wheel set 50 advantageously enables avoiding damage to the timepiece movement, particularly damage to the components of the motion chain of the hand setting device 10. Specifically, such damage is likely to occur when the winding drum 11 is rotationally driven in the second direction while the casket 40 is locked so that it does not rotate.

[0028] As shown in Figure 1, the friction wheel set 50 is positioned on the needle setting gear train 20 and is configured such that motion is not transmitted from the winding stem 11 to the 24-hour wheel 31 when the winding stem 11 is rotating in the second direction and the mainspring barrel 40 is forced to the stop position by the click mechanism 41.

[0029] In a preferred exemplary embodiment of the present invention, the friction wheelset 50, as seen in the cross-sectional view in Figure 2, includes a driven wheel 51 coupled without a degree of freedom to one end of a spindle 52, the spindle 52 including a platform 53 at the other end. The driven wheel 51 has a pipe 510 extending toward the platform 53. The platform 53 preferably has an annular shoulder 530 that houses a drive wheel 54. The drive wheel 54 is mounted to rotate freely relative to the platform 53. The drive wheel 54 is meshed with one of a plurality of intermediate wheels 21, as seen in Figure 1.

[0030] The friction wheelset 50 further includes a flange 55 that is immobile relative to the spindle 52. The flange 55 includes an upper annular lip 550 that faces and abuts against the drive wheel 54, and a lower annular lip 551 that extends axially and faces 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 stress is applied to the elastic member 56 by the lower annular lip 551 and the pipe 510.

[0031] In a preferred exemplary embodiment of the present invention, the elastic member 56 is composed of a component that is flat in a static state and curves under stress. The elastic member is formed, for example, by a disc having a plurality of radial lobes on its periphery, the lobes intended to abut against the lower annular lip 551. The fact that the elastic member 56 is formed of a component that is flat in a static state facilitates manufacturing and ensures compliance with manufacturing tolerances. Advantageously, the mechanical stress is evenly distributed by these lobes. To facilitate the assembly of the friction wheelset 50, pins 57 may be engaged with corresponding holes in the platform 53 and the flange 55 to ensure that they rotate as a unit.

[0032] Stress is applied to the elastic member 56 in such a way that it applies pressure to the lower annular lip 551 of the flange 55. This causes the drive wheel 54 to be tightened between the upper annular lip 550 of the flange 55 and the platform 53. That is, the drive wheel 54 transmits rotational motion to the driven wheel 51 up to a predetermined friction torque, but beyond that friction torque, the upper annular lip 550 and the platform 53 slide against the drive wheel 54. This friction torque is generated when the barrel 40 is locked in place by the click mechanism 41 and the winding stem 11 rotates in the second direction.

[0033] The application of stress to the elastic member 56, particularly to the disc having radial lobes, allows for a controlled friction torque, thus facilitating the manufacture and assembly of the friction wheelset 50.

[0034] Furthermore, the interface between the platform 53 and the drive wheel 54 advantageously has a tapered cross-section. The same applies to the interface of the lower annular lip 551, which is intended to receive the elastic member 56 in contact. The specific arrangement of these surfaces allows for greater control over friction torque.

[0035] As shown in Figures 1 and 3, the needle setting gear train 20 includes a plurality of intermediate wheels 21 that allow the winding stem 11 and the friction wheelset 50 to be kinematically connected to one another. The needle setting gear train 20 further includes a transmission wheelset 60 kinematically interposed between the friction wheelset 50 and the time indicator 30. The transmission wheelset 60 meshes with the driven wheel 51, for example, via an intermediate wheel, as shown in Figure 1.

[0036] As shown in Figure 3, the transmission wheelset 60 is meshed with the 24-hour wheel 31, cannon pinion 32, and hour wheel 33 via the 24-hour pinion 61, minute wheel 62, and minute pinion 33, respectively.

[0037] The barrel 40 is configured such that the mainspring 40 receives pre-biasing when the winding stem 11 is rotating in the second direction and the click mechanism 41 is preventing the barrel 40 from rotating. This feature prevents the mainspring 40 from completely unwinding, and a predetermined amount of energy is stored in the barrel 40. In particular, this pre-biasing makes it possible to control the angular position of the barrel 40.

[0038] In general, it should be noted that the implementation examples and embodiments considered above are described as non-limiting examples, and that other alternative examples are also possible.

[0039] More specifically, in other exemplary embodiments of the present invention, the driven wheel 51 and the drive wheel 54 may be reversed without changing the operation of the friction wheel set 50. In other words, the wheel referred to as "driven wheel 51" in this text and shown in Figure 2 may be the drive side, and the wheel referred to as "drive wheel 54" may be the driven side.

Claims

1. A device (10) for a wristwatch for setting hands, comprising a winding stem (11) configured to occupy a hand setting position in which the winding stem (11) engages with a hand setting gear train (20) kinematically connected to a time indicator (30) and a 24-hour wheel (31), the 24-hour wheel (31) engaging with a barrel (40) including a mainspring (40) that supplies energy for displaying time values, the barrel (40) comprising a click mechanism (41), the click mechanism (41) configured to allow the barrel (40) to rotate more than one revolution when the winding stem (11) rotates in a first direction, and to limit the rotation of the barrel (40) to an angular amplitude corresponding to less than one revolution when the winding stem (11) rotates in a second direction for the purpose of setting the hands.

2. The device according to claim 1, wherein the needle setting gear train (20) includes a friction wheelset (50), the friction wheelset (50) is configured such that no motion is transmitted from the winding stem (11) to the 24-hour wheel (31) when the winding stem (11) rotates in the second direction and the mainspring barrel (40) is forced to the stop position by the click mechanism (41).

3. The device according to claim 2, wherein the needle setting gear train (20) includes a transmission wheelset (60) kinematically interposed between the friction wheelset (50) and the time indicator (30).

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

5. The device according to claim 1, wherein the barrel (40) is configured such that the mainspring (40) receives pre-energization when the winding stem (11) rotates in the second direction and the click mechanism (41) prevents the barrel (40) from rotating.

6. The device according to claim 1, wherein the click mechanism (41) includes a projection (410) eccentrically positioned on the barrel (40) and extending parallel to the axis of rotation of the barrel (40), and a lever (411) intended to cooperate with the projection (410), the lever (411) swings when the winding stem (11) rotates in the first direction and contacts the lever (411) when the winding stem (11) rotates in the second direction.

7. The device according to claim 2, wherein the friction wheel set (50) includes two wheels (51, 54), each wheel positioned at one end of a spindle (52) including a platform (53), one of the wheels (51, 54), referred to as the "first wheel" (51), has a pipe (510) that applies a deformable force to an elastic member (56), the elastic member (56) applies pressure to a flange (55), the flange (55) combines with the platform (53) to apply a clamping force to the other wheel, referred to as the "second wheel" (54).

8. The device according to claim 7, wherein the elastic member (56) is made of a component that is flat in a stationary state and curves when stress is applied.

9. The device according to claim 8, wherein the elastic member (56) is formed by a disc having a plurality of radial lobes on its periphery, and these lobes are intended to abut against the flange (55) such that the flange is rigidly attached to the elastic member (56) so that they rotate together as a unit.

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