Patent Application
20160132022
This application claims priority from European patent application No. 14192336.7 filed Nov. 7, 2014, the entire disclosure of which is hereby incorporated herein by reference.
The invention concerns a winding device with a unidirectional drive arrangement for a watch. This device may be used for winding a mainspring for driving a timepiece movement or for driving, for example, a date disc or time correction disc. The device includes at least one solar drive pinion mounted for free rotation about a central arbor disposed coaxially on a winding wheel, which may be connected to the mainspring barrel of the timepiece movement.
Usually, in a system for winding at least one barrel, or for setting the time or correcting the date, there is used a wheel with wolf teeth cooperating with two clicks. The two clicks are held by small springs against the wheel to prevent rotation in one direction and to allow free rotation in another direction. Another click must also be provided under the wheel of the frame to prevent the mainspring from being wound. This locking click under the wheel is difficult to access which makes disassembly difficult, especially of the barrel or parts connected to the barrel. This generally constitutes a drawback of such a winding system.
In EP Patent Application No. 0 278 338 A1, there is described a reverser mechanism for an automatic winding device using an oscillating weight of a watch movement. The mechanism includes a winding wheel, which is coaxially mounted with two wheels having wolf teeth, which are disposed on either side of the winding wheel. This winding wheel carries on each face thereof at least one click loaded by a spring and respectively cooperating with one of the wolf teeth wheels. This assembly is disposed in the kinematic chain of the movement, inserted between the oscillating weight and the mainspring barrel of the watch. These clicks are intended for the transmission of the rotation of the oscillating weight, and are arranged respectively hinged on pivoting members, which are integral with the winding wheel. Each pivoting member, which carries the click assigned to one direction of rotation of the oscillating weight, also serves as an anchoring member for the spring, which loads the click intended for the transmission of the other direction of rotation of said oscillating weight. However, this mechanism with the winding device includes too many parts, which makes maintenance of the watch difficult and constitutes a drawback.
EP Patent Application No. 2 221 676 A1 discloses a timepiece which includes a chronograph and a watch. The chronograph hands are driven by a first gear train, which in turn drives a first resonator. The watch hands are driven by a second gear train independent of the first gear train, which in turn drives a second resonator. The first and second gear trains are driven by a single energy source. The energy source is a barrel which rotates freely about an arbor and contains a mainspring. This mainspring may be wound by driving a wheel with wolf teeth mounted on the barrel arbor and impeded in one direction of rotation by clicks. However no unidirectional drive arrangement is defined in connection with the barrel.
CH Patent Application No. 173 803 A describes a device for winding a watch, which is a unidirectional drive arrangement. The device includes a solar drive pinion, which is mounted for free rotation about a central arbor coaxially secured to a winding wheel. It also includes a toothed planetary wheel for meshing with a toothing of the solar pinion. The toothed planetary wheel is mounted for free rotation about an offset arbor fixed to the wheel and parallel to the central arbor. It also includes a hook fixedly mounted to the winding wheel in order to mesh with the toothed planetary wheel in one direction of rotation. The device further includes a relatively complicated mechanical arrangement for allowing unidirectional driving, which is a drawback.
Reference may also be made to CH Patent Application Nos 308 939 A and 308 940 A, which describe a winding device, in a similar manner to CH Patent Application No. 173 803 A, and which also include a relatively complicated mechanical arrangement for allowing unidirectional driving, which is a drawback.
It is an object of the invention to overcome the aforementioned drawbacks of the state-of-the-art by providing a winding device with a unidirectional drive arrangement, which is of simple design and which can easily allow a part of the movement with the barrel to be maintained or disassembled for repair.
The invention therefore concerns a winding device with a unidirectional drive arrangement, for a watch, the device including at least one solar drive pinion mounted for free rotation about a central arbor integral with a winding wheel and arranged coaxially to said winding wheel,
Particular embodiments of the winding device with a unidirectional drive arrangement are defined in the dependent claims 2 to 16.
One advantage of the winding device lies in the fact that there is no longer a requirement for multiple small springs and clicks preventing winding in order to obtain a unidirectional drive arrangement, particularly to be used for winding a mainspring. This differs from winding systems of the prior art. In this case, the winding device allows the mainspring to be loaded or wound by an action directly on the central arbor connected to the centre of the barrel. The central arbor may be connected to an inner end of the mainspring. In a first direction of rotation of a solar pinion of the device, the winding wheel connected to the central arbor is driven in rotation to wind the spring. In a second direction of rotation of the solar pinion, uncoupling occurs without driving the winding wheel.
One advantage of the winding device lies in the fact a lower portion of the solar pinion includes truncated teeth to facilitate the locking of each toothed planetary wheel in contact with at least one hook in the first direction of rotation of the solar pinion. Each toothed planetary wheel is mounted with a certain play about an offset arbor fixed to the winding wheel. This makes it possible to obtain a locking position in a first direction of rotation of the solar pinion and an uncoupling or free rotation position in a second direction of rotation of the solar pinion.
To this end, the invention concerns an assembly for the winding of at least one mainspring of at least one barrel of a timepiece movement of a watch by means of a winding device,
A particular embodiment of the assembly is defined in the dependent claim 18.
The objects, advantages and features of the winding device with a unidirectional drive arrangement will appear more clearly in the following description, based on at least one non-limiting embodiment illustrated by the drawings, in which:
In the following description, reference is mainly made to the operation of the winding device with a unidirectional drive arrangement notably for winding a barrel mainspring of a mechanical watch. However, it is also possible to envisage using such a winding device to act on one or more date discs or time indicator hands.
Winding device 1 also includes at least one toothed planetary wheel 3 for meshing with a toothing of solar pinion 2. Toothed planetary wheel 3 is mounted for free rotation with a certain play 4 about an offset shaft or arbor 7 parallel to central arbor 22. This offset arbor 7 is fixed perpendicularly to winding wheel 5. The diameter of the opening of toothed planetary wheel 3 may be between 20% and 30%, and preferably close to 25%, of the diameter of offset arbor 7 to define the certain free rotational play.
Winding device 1 also includes at least one hook 9, fixedly mounted on winding wheel 5, in order to mesh with a tooth of toothed planetary wheel 3 according to the position of toothed wheel 3 about offset arbor 7. In a first direction of rotation of solar pinion 2 which is direction “a” shown in
In a second direction of rotation of solar pinion 2, which is opposite to the first direction of rotation and which is the direction “b” shown in
Preferably, as shown in
With the two toothed planetary wheels 3, 3′, winding device 1 may also include two hooks 9, 9′ fixedly mounted on winding wheel 5. A first hook 9 is opposite the first toothed planetary wheel 3, whereas a second hook 9′ is opposite the second toothed planetary wheel 3′. When solar pinion 2 is driven in rotation in the first direction of rotation, at least one of the toothed planetary wheels 3, 3′ meshes in a locking position with at least one of hooks 9, 9′. This allows winding wheel 5 to be driven in rotation. In the second direction of rotation of solar pinion 2, the tooth planetary wheels are uncoupled and do not drive winding wheel 5.
Winding device 1 preferably also includes a frame 6 fixedly mounted in a coaxial manner on winding wheel 5. This frame encloses in a housing toothed planetary wheel 3 or toothed planetary wheels 3, 3′. The housing includes an upper wall covering toothed planetary wheels 3, 3′ and two side walls parallel to each other and to the line joining central arbor 22 and offset arbors 7, 7′. The distance separating each side wall is substantially similar to the diameter of solar pinion 2. Preferably, the housing is open on two opposite sides allowing a portion of each planetary wheel 3, 3′ to pass. Frame 6 includes at least the first hook 9 for impeding rotation of toothed planetary wheel 3 in the first direction of rotation of solar pinion 2. According to the embodiment of
Since the two toothed planetary wheels 3, 3′ have the same diameter, the two hooks 9, 9′ are equidistant from central arbor 22. They are each made in the form of a portion that curves inwardly from one of the respective side walls of the housing of the frame, which encloses the two planetary wheels 3, 3′. The two hooks 9, 9′ are arranged at 180° from each other with respect to central arbor 22. One of the hooks is made at the periphery of frame 6 on one of the side walls of the housing, and the other hook is made at the periphery of frame 6 on the other side wall. With respect to the centre of central arbor 22, the two hooks 9, 9′ are offset by an angle comprised between 20° and 30°, preferably 25°, from the two toothed planetary wheels 3, 3′. They are offset by an angle of between 20° and 30° in the first direction of rotation of solar pinion 2.
The two hooks 9, 9′ in frame 6 may also be arranged offset at an angle of between 20° and 30° in the second direction of rotation of solar pinion 2 in the embodiment of
Frame 6 is fixed on winding wheel 5, which is a wheel with wolf teeth 15, by two screws 8 inserted in openings 6a of the frame and screwed into threaded openings 5a of winding wheel 5. Openings 6a are made in a solid part of the frame and are arranged in a perpendicular direction to the direction of offset arbors 7, 7′ of toothed planetary wheels 3, 3′. Frame 6 also includes two passage openings 6b for offset arbors 7, 7′ in order to hold toothed planetary wheels 3, 3′ locked between winding wheel 5 and the interior of the housing of frame 6.
The frame also includes an upper opening 14 for the passage of an upper portion 2a of solar pinion 2. This upper portion 2a of solar pinion 2, which projects from frame 6 fixed to winding wheel 5, is capable of being driven in rotation in the first direction of rotation and the second direction of rotation by a toothed drive wheel (not shown). This toothed drive wheel is connected to an oscillating mass (not shown) of a timepiece movement of the watch. Solar pinion 2 also includes a lower portion 2b for meshing with the toothed planetary wheel or wheels 3, 3′. The teeth of lower portion 2b of solar pinion 2 are truncated to facilitate the locking of at least one tooth of the toothed planetary wheel or wheels 3, 3′ between two teeth of lower portion 2b. The locking of at least one of toothed planetary wheels 3, 3′ occurs in the first direction of rotation of solar pinion 2.
It is also to be noted that winding wheel 5 includes a central opening 16, which is of rectangular section for cooperating with a complementary-shaped portion of central arbor 22. This makes central arbor 22 integral with winding wheel 5 during the rotation of winding wheel 5. A low portion (not shown) of central arbor 22 is intended to be connected to one end of a mainspring 23 of the barrel 21, shown in
To define certain dimensions of the components of winding device 1, the external diameter of each toothed planetary wheel 3, 3′ could be between 1.3 and 1.5 times smaller than the external diameter of solar pinion 2. For example, the external diameter of each toothed planetary wheel 3, 3′ could be on the order of 3 mm and the external diameter of solar pinion 2 on the order of 4 mm. The diameter of tubular opening 12 of solar pinion 2 could be on the order 1.5 mm. The diameter of each offset arbor may be on the order of 0.7 mm, whereas axial opening 4 of each toothed planetary wheel 3, 3′ may be on the order of 0.9 mm. Each hook 9, 9′ may be on the order of 2.6 mm from the centre of central arbor 22. With such dimensions, toothed planetary wheels 3, 3′ may comprise 7 teeth, whereas solar pinion 2 may comprise 10 teeth.
Referring to
The lower portion of central arbor 22 of the device is connected to an inner end of mainspring 23. The attached end of mainspring 23 is on the centre side of the spiral spring. Mainspring 23 can thus be wound during the rotation of solar pinion 2, particularly in the first direction of rotation. To achieve this, the upper portion 2a of solar pinion 2 can mesh with a toothed drive wheel (not shown) connected to an oscillating weight of a timepiece movement.
Assembly 10 also includes a locking click 20, which is normally mounted on an assembly bridge or plate of the timepiece movement, which is not shown. One tooth 25 of looking click 20 impedes the rotation, in one direction of rotation, of winding wheel 5, which is a wheel with wolf teeth 15.
Tooth 25 impedes the rotation of the wheel with wolf teeth 15 in the second direction of rotation of the winding device 1 shown with reference to
In a more developed embodiment of assembly 10, it is possible to provide a first mainspring 23 of a first barrel 21, which can be wound by means of a first winding device 1 shown in
From the description that has just been given, several variant embodiments of the winding device can be devised by those skilled in the art without departing from the scope of the invention defined by the claims. More than two toothed planetary wheels may be provided, respectively cooperating with more than two hooks. The winding device may also be used for setting the time and activated by means of a stem crown of the watch.
| Number | Date | Country | Kind |
|---|---|---|---|
| 14192336.7 | Nov 2014 | EP | regional |
