Clutch device for a clock

Abstract

To provide a clutch device for timepieces for ensuring that component motion is not hindered in an open state or not prevented by excessive friction.SOLUTION: The clutch device for timepieces comprises: a clutch input wheel 1 capable of freely rotating on a shaft 2 and located to be displaceable in the axial direction; a clutch output wheel 6 firmly located on the shaft; a first clutch display 4 that freely rotates on the shaft and is located to be displaceable in the axial direction, and that comes into contact with the clutch input wheel by a spring force and loads the clutch input wheel so as to come into contact with a second clutch disk 3 in a frictional engagement manner; and further an annual groove 7 which is opened toward the radial outward on the outer circumferential surface in circumferential direction of the first clutch disk, in which a claw 8 engages with the inside of the annular groove, with the first clutch disk moving from a joining position at which the clutch input wheel is loaded to a non-joining position at which it is raised from the clutch input wheel, and the claw moving to the shaft 2 in the axial direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a clutch device for a timepiece. The clutch device includes a rotationally driven clutch input wheel that is freely rotatable on a shaft fixed in the axial direction and is displaceable in the axial direction, a clutch output wheel firmly arranged on the shaft, and a first clutch disk that is freely rotatable on the shaft and is displaceable in the axial direction. The first clutch disk can be loaded so as to abut against the clutch input wheel by a spring force, and can also be loaded so as to abut against a second clutch disk that is non-rotatable relative to the shaft and is firmly fixed in the axial direction in a frictionally engaging manner. The first clutch disk has an annular groove that is open radially outward on the outer circumferential surface in the circumferential direction. A claw engages radially in the annular groove. By this claw, the first clutch disk can move from a coupling position where it loads the clutch input wheel to a non-coupling position where it is lifted from the clutch input wheel. The claw is drivable to move in the axial direction with respect to the shaft.

Background Art

[0002] In such a clutch device for a timepiece, it is known that in the open state of the clutch device, the claw remains engaged with the first clutch disk. As a result, the movement of the components in the clutch device is obstructed or hindered by friction. For example, in a chronograph, there is a functional state where the clutch device must be opened but the components must be rotated under the influence of the claw and its operating elements. This applies, for example, when setting the hands of a chronograph to zero.

[0003] In this case, the functions and configurations of the clutch device are contradictory. This is because, on the one hand, the clutch spring must be strong enough to meet all the requirements for transmitting the clutch force. On the other hand, it is preferable that the zero setting of the chronograph hand can be smoothly performed with a slight force. The clutch spring that generates the clutch force when the clutch is closed also has an effect when the clutch is open, but it is biased more strongly by the axial path of the clutch. In the open state of the clutch, the claws are engaged and loaded by the force of the clutch spring. In this case, the clutch spring generates a frictional moment on the outer operating element and hinders the zero setting movement when zero-setting the chronograph hand. However, this contradicts the purpose of minimizing the force generated during zero setting. Depending on the moment to be transmitted by the clutch, the design of the operating element, and other requirements for the clutch device and the chronograph mechanism, the requirements are so contradictory that no satisfactory or practical solution can be found.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem of the present invention is to avoid the above-mentioned drawbacks in a clutch device for a watch of the type described at the beginning, and to prevent the movement of parts from being hindered or prevented by excessive friction in the open state.

Means for Solving the Problems

[0005] To solve this problem, the present invention is characterized in that the first clutch disk is composed of a friction disk region on the inner or outer radius and a clutch ring that surrounds or encloses this friction disk region in the radial direction and has an annular groove, and the inner friction disk region and the clutch ring are connected to each other in the radial direction by a rolling bearing.

[0006] Preferably, the watch is a chronograph.

[0007] Due to the configuration according to the present invention, in the released state of the clutch device, the friction against the pawl is at least significantly reduced. This is because the pawl no longer engages directly with the first clutch disk but engages with the rolling bearing. In the case of a chronograph, this means that the friction between the pawl and the clutch device is significantly reduced during zero setting.

[0008] In the so-called principle of connected sub-zero setting, the second hand counter is also set to zero from the minute counter via a closed gear train.

[0009] The clutch device rotates multiple times as part of this gear train. In this case, the friction against the pawl has a particularly adverse effect. This friction and the increased wear in the pawl and the first clutch disk are avoided.

[0010] Preferably, the first clutch disk and the clutch ring are connected to each other radially by a ball bearing.

[0011] If the pawl is axially displaceable between a non-operating position and an operating position relative to the shaft, the clutch ring is also axially loaded. In this case, no radial force acts on the clutch.

[0012] In this case, the pawl can be moved by a manually operable reset pusher from a non-operating position where the first clutch disk is not loaded to an operating position where the first clutch disk is lifted.

[0013] For this purpose, in a simple configuration, the pawl is arranged on a guide shaft that is displaceable parallel to the shaft, and this guide shaft is movable directly or indirectly by the reset pusher.

[0014] In a simple configuration, the first clutch disk can be loaded by a compression spring so as to be in frictional engagement with the clutch input wheel.

[0015] When the present invention is applied to a chronograph, the shaft fixed in the axial direction can support a clutch output wheel engaged with the second counter wheel in a non-rotatable manner relative to each other.

[0016] A further clutch output wheel supported non-rotatably by the shaft can be engaged with the minute counter wheel.

[0017] Hereinafter, an embodiment of the present invention in the drawings will be described in more detail.

Brief Description of the Drawings

[0018]

Figure 1

Mode for Carrying Out the Invention

[0019] The illustrated clutch device includes a clutch input wheel 1, which is rotatably mounted on a shaft 2, freely rotatable and displaceable in the axial direction, and is rotatably driven by a movement (not shown) of the chronograph.

[0020] On the shaft 2, below the clutch input wheel 1, a lower clutch disk 3 is arranged in a non-rotatable and axially fixed state.

[0021] On the clutch input wheel 1 on the side away from the lower clutch disk 3, an upper clutch disk 4 is arranged on the shaft 2, freely rotatable and displaceable in the axial direction, and is loaded in the direction of the clutch input wheel 1 by the spring force of a compression spring 5.

[0022] The upper end of the shaft 2 supports a firmly arranged clutch output wheel 6.

[0023] The claw 8 region protruding radially from the annular groove is firmly connected to a guide shaft 9 parallel to the shaft 2, and the guide shaft 9 is guided axially displaceably within an axial bearing 10 with respect to the shaft 2.

[0024] The upper clutch disk 4 has an annular groove 7 that is open radially outward and downward on its circumferential outer peripheral surface.

[0025] A claw 8 engages radially within the annular groove 7. The claw 8 is axially movable with respect to the shaft 2. By loading the upper side wall 15 of the annular groove 7 with the claw 8, the upper clutch disk 4 can move from a coupling position where it loads the clutch input wheel 1 to a non - coupling position where it is lifted from the clutch input wheel 1.

[0026] The claw 8 region protruding from the annular groove 7 is firmly connected to a guide shaft 9 parallel to the shaft 2, and the guide shaft 9 is guided axially displaceably within an axial bearing 10 with respect to the shaft 2.

[0027] The upper clutch disk 4 is composed of a radially inner friction disk region 11 and a clutch ring 12 that radially surrounds this friction disk region 11. The friction disk region 11 and the clutch ring 12 are connected to each other by a ball bearing 13. In this case, the friction disk region 11 forms the inner ring, the clutch ring 12 forms the outer ring, and the balls 14 of the ball bearing 13 are arranged between them.

[0028] The clutch ring 12 has an annular groove 7 that is open radially outward on its circumferential outer peripheral surface. This annular groove 7 has a radially directed side wall 15.

[0029] Within the annular groove 7, a claw 8 firmly arranged on a guide shaft 9 parallel to the shaft 2 protrudes radially.

[0030] The guide shaft 9 is displaceable from a non - operating position to an operating position by a manually operable reset pusher (not shown).

[0031] When the guide shaft 9 is in its normal lower non-operating position (not shown), the claw 8 is not axially in contact with the side wall 15 of the annular groove 7. Therefore, the compression spring 5 presses the upper clutch disk 4 having the friction disk region 11 against the clutch input wheel 1, and thus the clutch device is held in the engaged position.

[0032] When the guide shaft 9 and, accordingly, the claw 8 are moved from the lower non-operating position to the upper operating position, the claw 8 abuts against the side wall 15 of the annular groove 7 and lifts the upper clutch disk 4 having the friction disk region 11 against the spring force of the compression spring 5 from the clutch input wheel 1, whereby the clutch device is positioned in the disengaged position.

[0033] As a result, the rotational connection state that has existed until then between the clutch input wheel 1 and the clutch output wheel 6 is also released.

Explanation of reference numerals

[0034] 1 Clutch input wheel 2 Shaft 3 Lower clutch disk 4 Upper clutch disk 5 Compression spring 6 Clutch output wheel 7 Annular groove 8 Claw 9 Guide shaft 10 Axial bearing 11 Inner friction disk region 12 Clutch ring 13 Ball bearing 14 Ball 15 Side wall

Claims

1. A clutch device for a timepiece, comprising: a rotationally driven clutch input wheel (1) arranged freely rotatable and axially displaceable on an axially fixed shaft (2); a clutch output wheel (6) rigidly mounted on said shaft (2); a first clutch disc (4) arranged freely rotatably and axially displaceably on the shaft (2), which can be loaded by a spring force into abutment against the clutch input wheel (1), and which can be loaded into frictionally engaging abutment against a second clutch disc (3) fixed rigidly axially and non-rotatably on the shaft (2); an annular groove (7) that is open radially outward on the circumferential outer surface of the first clutch disc (4), and a pawl (8) radially engages with the annular groove, and the first clutch disc (4) is movable from an engaged position in which the first clutch disc (4) applies load to the clutch input wheel (1) to a non-engaged position in which the first clutch disc (4) is lifted from the clutch input wheel (1) by the pawl (8); Equipped with 1. A clutch arrangement in which the pawl (8) is drivable for axial movement relative to the shaft (2), 1. A clutch device according to claim 1, wherein the first clutch disc (4) is composed of a radially inner or outer friction disc area (11) and a clutch ring (12) radially surrounding or encircling the friction disc area and having the annular groove (7), the inner friction disc area (11) and the clutch ring (12) being radially connected to each other by a rolling bearing.

2. 2. The clutch device according to claim 1, characterized in that the inner friction disc area (11) and the clutch ring (12) are radially connected to each other by means of ball bearings (13).

3. 2. A clutch device according to claim 1, characterized in that the pawl (8) is displaceable relative to the shaft (2) between an inoperative position and an operative position.

4. 4. The clutch device according to claim 3, characterized in that the pawl (8) is movable by a manually operable reset pusher from a non-operating position in which the first clutch disc (4) is not loaded to an operating position in which the first clutch disc (4) is lifted.

5. 5. The clutch device according to claim 4, characterized in that the pawl (8) is arranged on a guide shaft (9) displaceably guided parallel to the shaft (2), the guide shaft being directly or indirectly movable by the reset pusher.

6. 2. The clutch arrangement of claim 1, wherein the first clutch disc (4) is loaded into frictionally engaging contact with the clutch input wheel (1) by a compression spring (5).

7. 2. A clutch device according to claim 1, characterized in that the axially fixed shaft (2) supports a clutch output wheel which engages with a seconds counter wheel in a non-rotatable manner relative thereto.

8. 2. A clutch arrangement according to claim 1, characterized in that a further clutch output wheel, supported by the shaft so as not to rotate relative thereto, is engaged with the minute counter wheel.

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