CH714615A2 - Mechanism for transmitting an arming force, movement and mechanical timepiece. - Google Patents

Abstract

The object of the invention is to propose an armature force transmission mechanism, a movement and a mechanical timepiece able to effectively reduce energy losses at the time of automatic winding. The armature force transmission mechanism comprises: a sliding transmission wheel (33) meshing with a crown wheel (20) rotated by means of a winding stem (17); a sliding wheel (34) which meshes with the sliding transmission wheel (33), which is provided to be tiltable about the axis (C) of the sliding transmission wheel (33) and which is movable into a meshing position, where it meshes with a ratchet (14), and a retracted position, where its meshing with the ratchet (14) is undone; and a tilt lever (40) able to keep the sliding wheel (34) in the retracted position.

Description

Description

BACKGROUND OF THE INVENTION

1. Field of the invention The present invention relates to a winding force transmission mechanism, a movement and a mechanical timepiece.

2. Description of the Related Prior Art [0002] As a mechanism for winding the barrel spring in a mechanical timepiece employing a barrel spring as a source of energy for driving the train, we sometimes use both a manual winding mechanism for winding, also called winding, by maneuvering a winding stem and an automatic winding mechanism carrying out winding by rotation of an oscillating weight.

In the manual winding mechanism, also called manual winding mechanism, a crown which is integral with the winding stem is manually rotated, whereby the rotation is transmitted to a transmission wheel via d '' a clutch wheel, a winding pinion, a crown wheel and an intermediate transmission wheel. Then, a röchet meshing with the transmission wheel is caused to rotate to arm the barrel spring.

In the automatic winding mechanism, also called automatic winding mechanism, a rotation of the oscillating mass is transmitted from an external wheel (first wheel), integral with the oscillating mass, to a first transmission wheel, and a feed element is driven by this first wheel, driving the transmission wheel in one direction by the drive of the feed element. As a result, the röchet meshing with the transmission wheel is caused to rotate to arm the barrel spring.

Here, in the automatic winding mechanism, the feed element rotates the transmission wheel in one direction, and this transmission wheel meshes with the intermediate transmission wheel forming part of the manual winding mechanism. In this constitution, the energy coming from the rotation of the oscillating mass of the automatic winding mechanism is consumed not only to wind the barrel spring, but also to turn the intermediate transmission wheel, the crown wheel and the pinion to wind up. In view of this, a technique has been proposed in which the intermediate transmission wheel is tiltable and in which the meshing between the intermediate transmission wheel and the transmission wheel is undone during an operation of the automatic winding mechanism.

In addition, this structure has a spring retainer to maintain the meshing between the intermediate transmission wheel and the transmission wheel for the duration of the automatic winding. As a result, during the duration of manual winding, the meshing between the intermediate transmission wheel and the transmission wheel is maintained. On the contrary, during the duration of the automatic winding, the meshing between the intermediate transmission wheel and the transmission wheel is released by an action against the restoring force of the retaining element, and the transmission wheel intermediate, the crown wheel and the winding pinion are not rotated. As a result, a reduction in energy losses from the automatic winding mechanism is obtained.

An example of the accompanying art includes document JP-A-2003-279 667.

However, it should be noted that, in the prior art described above, it is necessary to actuate the automatic winding mechanism against the restoring force of the retaining element for the duration of the automatic arming. Therefore, it cannot be said with certainty that the problem with the energy loss of the automatic winding mechanism could have been effectively or effectively resolved.

SUMMARY OF THE INVENTION One aspect of the present application is to propose a winding force transmission mechanism, a movement and a mechanical timepiece which are capable of effectively or efficiently reducing energy loss during automatic arming.

In order to achieve the above aspect, there is proposed, according to the present application, a mechanism for transmitting a winding force comprising:

a sliding transmission wheel meshing with a crown wheel rotated by an operation of a winding rod, a sliding wheel which meshes with the sliding transmission wheel, which is provided so as to be tiltable around an axis of rotation of the sliding transmission wheel which is movable to a meshing position, in which it meshes with a röchet, and to a retracted position, in which it does not mesh with the röchet, and holding means in the retracted position able to maintain the sliding wheel in the retracted position.

CH 714 615 A2 In this way, due to the means for holding in the withdrawn position, the sliding wheel is kept in the withdrawn position where its engagement with the röchet is undone. In other words, when the röchet rotates during automatic arming, the röchet and the sliding wheel do not mesh with each other, and this state is maintained. Thus, no excess load is applied to the röchet and it is possible to prevent the rotation of the röchet from being transmitted to the sliding transmission wheel and to the crown wheel. Thus, energy loss during automatic arming can be effectively reduced.

According to the present application, there is provided a winding force transmission mechanism, further comprising means for holding in the engagement position capable of maintaining the sliding wheel in the engagement position.

Thanks to this constitution, it is possible to keep the sliding wheel and the röchet meshing during manual winding. Thus, it is possible to reduce as much as possible the number of times that noises and shocks are produced during an engagement between the röchet and the sliding wheel. Thus, it is possible to propose a winding force transmission mechanism having greater ease of use.

According to the present application, there is provided a winding force transmission mechanism, further comprising a sliding wheel bridge which supports the sliding wheel and which has an opening along a tilting trajectory of the wheel sliding, while the sliding wheel is fixed to one end of a sliding wheel shaft inserted into the opening, that, at a proximal end of the sliding wheel shaft through the sliding wheel bridge, there is provided a flange portion in contact with the sliding wheel bridge, and that the means for holding in the retracted position and the means for holding in the engagement position are made of an elastic member urging the flange portion against the sliding wheel bridge.

Thanks to this constitution, it is possible to maintain the sliding wheel in the retracted position and in the engagement position by using a friction resistance generated when the flange portion is pressed against the sliding wheel bridge. Thus, the means for holding in the retracted position and the means for holding in the engagement position can have a simple construction and a size as small as possible.

According to the present application, there is provided a winding force transmission mechanism, in which the elastic member is a leaf spring, a distal end of which is located between the sliding wheel bridge and the sliding wheel, a proximal end of the leaf spring being carried so as to be rotatable about an axis of rotation of the sliding transmission wheel.

Thanks to this constitution, the elastic member can be arranged in a way that saves space, so that a further reduction in the size of the winding force transmission mechanism can be obtained.

According to the present application, there is provided a winding force transmission mechanism, in which the elastic member has a C-shaped support portion formed to surround a pivot carrying the sliding transmission wheel, and a lever portion extending from both ends of the support portion to the sliding wheel, the lever portion being tiltable by an elastic deformation relative to the support portion, in the axial direction of the wheel shaft sliding.

Thanks to this constitution, the elastic member can be configured so as to have a simple constitution and to save space. In addition, by adjusting the angle between the support portion and the lever portion, one can easily adjust the biasing force with which the sliding wheel shaft is pressed against the flange portion. Thus, it is possible to provide a small armor power transmission mechanism with excellent ease of use.

According to the present application, there is provided a movement comprising a winding force transmission mechanism as defined above.

Thanks to this constitution, it is possible to propose a movement allowing an effective reduction of the loss of energy during automatic arming.

According to the present application, there is provided a mechanical timepiece comprising a movement as defined above.

Thanks to this constitution, it is possible to propose a mechanical watch allowing an effective reduction of the loss of energy during automatic winding.

According to the present application, thanks to the means for holding in the withdrawn position, the sliding wheel is kept in the withdrawn position where this sliding wheel does not mesh with the röchet. In other words, when the röchet rotates during automatic winding, the röchet and the sliding wheel do not mesh with each other and this state is maintained. Thus, no excess load is applied to the röchet and it is possible to prevent a rotation of the röchet from being transmitted to the sliding transmission wheel and to the crown wheel. Thus, energy loss during automatic arming can be effectively reduced.

CH 714 615 A2

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an external plan view of a mechanical timepiece according to an embodiment of the present invention.

Fig. 2 is a plan view, from the front side, of a movement according to an embodiment of the present invention.

Fig. 3 is a detail view, in plan, on the periphery, from the front side, of a winding stem and of a winding force transmission mechanism according to an embodiment of the present invention.

Fig. 4 is a section along line l-l of FIG. 2.

Fig. 5 is a plan view of a tilting lever according to an embodiment of the present invention.

Fig. 6 is a side view, in the free state, of a tilting lever according to an embodiment of the present invention.

Fig. 7 is an explanatory view showing how a tilting lever in the free state is mounted in a movement according to an embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS We will now describe an embodiment of the present invention, with reference to the drawings.

Mechanical timepiece [0027] FIG. 1 is an external plan view of a mechanical timepiece 1.

The mechanical assembly including the drive part of the mechanical timepiece 1 is generally called a "movement 10". A dial 4 and hands (an hour hand 5, a minute hand 6 and a second hand 7) are assembled with movement 10, and the assembly is placed in a timepiece box 3 in order to obtain a complete set, which is called the complete mechanical timepiece. Among the two sides of the plate 11 forming the support plate of the mechanical timepiece 1, the side where there is the crystal 2 of the timepiece case 3 (the side where there is the dial) is called the “rear side” of the movement 10. Among the two sides of the plate 11, the side where there is the bottom of the timepiece case 3 (the side opposite to the dial) is called the “front side »Of movement 10. Each of the wheels described below has an axis of rotation extending in the front-rear direction of movement 10.

As shown in fig. 1, the complete mechanical timepiece 1 comprises, inside the timepiece case 3 consisting of a rear case body (not shown) and the crystal 2, the movement 10, the dial 4 carrying a graduation or the like for indicating at least one piece of information relating to time, as well as indicator needles comprising an hour hand 5 to indicate the hours, a minute hand 6 to indicate the minutes and a second hand 7 to indicate the seconds. Mechanical timepiece 1 is what is commonly known as an automatic winding wristwatch. During the duration of automatic winding, the mechanical timepiece 1 sees its oscillating mass (not shown) rotate due to a movement of the user, whereby the barrel spring (not shown, also called a motor spring) ) which is the source of energy is armed via an automatic winding train (including a röchet 14 described below). In addition, in the mechanical timepiece 1, it is also possible to manually wind the barrel spring (not shown) by means of the röchet 14. In the mechanical timepiece 1, a crown is rotated 8 during manual winding, whereby a barrel spring 23 is armed via a winding force transmission mechanism 30 (manual winding cog) (the operation of the force transmission mechanism reinforcement 30 will be described in detail below).

Movement [0030] FIG. 2 is a plan view of the movement 10 as seen from the front side.

As shown in fig. 2, the movement 10 comprises the plate 11, a winding rod 17 fitted to the plate 11, a gear train bridge 12 disposed on the front side of the plate 11, a movement barrel 13 supported so as to be rotatable between the plate 11 and the gear train 12, the röchet 14 mounted coaxially with the movement barrel 13, a finishing train (not shown), an exhaust / regulation mechanism 18, etc. The gear train (not shown) is a power transmission mechanism transmitting the energy from the movement barrel 13 to the exhaust / regulation mechanism 18 and it has a center mobile, an average mobile and a seconds mobile. (not shown), etc. The exhaust / regulating mechanism 18 has a balance spring 15, a

CH 714 615 A2 mobile exhaust 16, etc., and it oscillates in a fixed cycle due to the energy of the movement barrel 13 transmitted via the gear train.

[0032] FIG. 3 is a detail view, in plan, from the front side, of the periphery of the winding rod 17 and of the winding force transmission mechanism 30, the plate 11 and the gear train 12 of FIG. 2 being omitted.

The winding stem 17 equips the plate 11 so as to be sliding in a direction orthogonal to the direction of the axes of rotation of the finishing train and so as to be rotatable. The position of the winding stem 17 in the axial direction is determined by a switching mechanism (not shown) having an adjustment lever, a rocker, a rocker spring, etc. In addition, a winding pinion 24 is provided on the portion forming a guide shaft of the winding rod 17 so as to be rotatable relative to this winding rod 17 and so as to be stationary in the axial direction.

The crown 8 is provided at the proximal end of the winding stem 17, so as to be integral with the latter. When the crown 8 is turned, the winding stem 17 rotates.

In addition, on the portion of the winding stem 17 located on the side of the distal end relative to the winding pinion 24, there is provided a clutch wheel 19 (sliding pinion) mounted so as to be axially movable relative to the winding stem 17 and so as to be non-rotatable. The winding pinion 24 and the clutch wheel 19 are arranged so as to be able to mesh with each other. In addition, the clutch wheel 19 is formed so as to be able to mesh with an adjustment wheel (not shown) used when setting the time. Furthermore, a crown wheel 20 meshes with the winding pinion 24. The crown wheel 20 is rotatably carried by a crown wheel shaft 22 (see FIG. 4) provided on the gear train bridge 12.

In this constitution, when the mechanical timepiece 1 must be armed manually, the winding stem 17 is, in the axial direction, at a first position of the winding stem (step 0) most inwardly movement 10. At this first winding stem position, the winding pinion 24 and the clutch wheel 19 mesh with each other. When the winding rod 17 is rotated in this state, the winding pinion 24 rotates by the rotation of the clutch wheel 19. Due to the rotation of this winding pinion 24, the crown wheel 20 meshing with this one turns. And due to the rotation of the crown wheel 20, the röchet 14 rotates by means of the winding force transmission mechanism 30. By the rotation of the röchet 14, the barrel spring (not shown) housed in the movement barrel 13 is armed.

[0037] FIG. 4 is a section along line l-l of FIG. 2.

As shown in fig. 4, the movement barrel 13 comprises a barrel drum 21 receiving the barrel spring (not shown), a barrel shaft supported by the plate 11 and a barrel bridge (not shown), etc. By rotation of the röchet 14, the barrel shaft rotates and the barrel spring is armed. When the barrel spring disarms (unwinds), the restoring force rotates the barrel drum 21, which causes the gear train.

Reinforcement force transmission mechanism [0039] As shown in figs. 3 and 4, the winding force transmission mechanism 30 mainly comprises a sliding wheel bridge 32 fixed on the front side of the gear wheel bridge 12 by means of a fixing screw 31, a sliding transmission wheel 33 supported by the sliding wheel bridge 32 so as to be rotatable, a sliding wheel 34 carried by the sliding wheel bridge so as to be tiltable, as well as a tilting lever 40 generating in the sliding wheel 34 a frictional force of resistance with respect sliding wheel bridge 32.

The sliding wheel bridge 32 is a plate-shaped element, extending from a position of the external peripheral portion of the barrel drum 21 somewhat at a distance from the crown wheel 20 so as to be elongated when it reaches the outer peripheral portion of the crown wheel 20. The proximal end of the sliding wheel bridge 32 located on the external peripheral side of the barrel drum 21 in the longitudinal direction is fixed to the gear train 12 by the fixing screw 31. In addition, at the distal end of the sliding wheel bridge 32 located on the side of the crown wheel 20 in the longitudinal direction, there is a through hole 32a in which a cylindrical portion 35 of the gear train 12 can be inserted.

The cylindrical portion 35 of the gear train 12 is formed so as to protrude towards the front side. The distal end of the cylindrical portion 35 is inserted into the through hole 32a of the sliding wheel bridge 32. A support screw 36 is inserted into the cylindrical portion 35. A head 36a of the support screw 36 has a disc shape . The distal end of the support screw 36, on the side opposite to the head 36a, is inserted from the front side of the cylindrical portion 35, and the head 36a is forced to be in abutment against the sliding wheel bridge 32, whereby the gear bridge 12 and the portion with the distal end of the sliding wheel bridge 32 are fixed to each other.

In addition, between the gear train bridge 12 and the sliding wheel bridge 32, the internal peripheral surface of a flanged bearing 37 is in adjusted engagement (flushing) with the external peripheral surface of the cylindrical portion 35. The flange bearing 37 has an outer flange 37a directed towards the side of the sliding wheel bridge 32. Thanks to the flange bearing 37, a space is obtained between the gear train bridge 12 and the sliding wheel bridge 32. At this space excluding the flange 37a, a sliding transmission wheel 33 is carried by the peripheral surface

CH 714 615 A2 external of the flanged bearing 37, so as to be rotatable. The sliding transmission wheel 33 meshes with the crown wheel 20.

The sliding wheel bridge 32 has an opening 38 substantially between the fixing screw 31 and the support screw 36. The opening 38 has an arcuate shape around an axis C of the support wheel 36 when the we look from the front side. A sliding wheel shaft 39 is inserted into the opening 38.

The sliding wheel shaft 39 has a main shaft body 41 and a head 42, which is disc-shaped, which is integral with the main shaft body 41 and which is located at level of the proximal end of this main shaft body 41. The width of the opening 38 in the transverse direction allows the insertion of the main shaft body 41 and does not allow the passage of the head 42, which forms a flanged portion. Opposite the head 42, the distal end of the sliding wheel shaft 39 is inserted from the front side of the sliding wheel bridge 32, and the head 42 is forced to abut against a surface on the front side. 32b of the sliding wheel bridge 32. In this way, the sliding wheel shaft 39 is tiltable along the opening 38, that is to say tiltable around the axis C of the support wheel 36.

Significantly at its center in the axial direction, the main shaft body 41 has a thinned portion 43 whose entire periphery is reduced by a shoulder. The distance W between the thinned portion 43 and the head 42 is chosen so as to be approximately somewhat greater than the thickness of the sliding wheel bridge 32. The sliding wheel 34 is fixed by adjusted engagement (driving) on the main body shaft 41, on the side of the distal end relative to the thinned portion 43. Thus, the sliding wheel 34 and the sliding wheel shaft 39 rotate together while being integral.

The sliding wheel 34 meshes with the sliding transmission wheel 33. The sliding wheel 34 is integral with the sliding wheel shaft 39 rocking along the opening 38 of the sliding wheel bridge 32, so that when 'it tilts, its engagement with the sliding transmission wheel 33 is maintained.

In addition, the tilting direction of the sliding wheel 34 is a direction in which it is moved in the direction or away from the röchet 14. The sliding wheel 34 is arranged so as to be also able to 'be engaged with the röchet 14. Thus, when it rocks, the sliding wheel 34 comes into a position of engagement with the röchet 14 or out.

[0048] FIG. 5 is a plan view of the tilting lever 40.

As shown in Figs. 3 to 5, the tilt lever 40 is placed along the sliding wheel bridge 32, at a position corresponding to the thinned portion 43 of the sliding wheel shaft 39.

The tilt lever 40 is a leaf spring consisting of an elastic metal plate. The tilting lever 40 comprises a support portion 44 cooperating in an adjusted and sliding manner with the external peripheral surface of the external flange 37a of the flange bearing 37. As seen from the front side, the support portion 44 has a shape of C and is arranged with its opening towards the side of the sliding wheel shaft 39. At the two ends of the support portion 44, there are a pair of lever portions 45a and 45b, which are in one piece and which extend towards the shaft side of the sliding wheel 39.

The distal ends of these lever portions 45a and 45b are mounted on the thinned portion 43 of the sliding wheel shaft 39. In positions corresponding to the thinned portion 43, the lever portions 45a and 45b have notches 46a and 46b able to receive the thinned portion 43. The notches 46a and 46b have a substantially arcuate shape when viewed from the front side. The radius of curvature of the notches 46a and 46b is chosen so as to be substantially equivalent to the radius of the thinned portion 43.

The lever portions 45a and 45b are formed so that the distance K between them outside the notches 46a and 46b is smaller than the shaft diameter of the sliding wheel shaft 39. The thinned portion 43 of the sliding wheel shaft 39 is held by and between the lever portions 45a and 46b thus formed.

In addition, at their distal ends, the lever portions 45a and 45b have inclined portions 47a and 47b such that the distance between the lever portions 45a and 45b gradually increases as one moves towards the distal ends. The inclined portions 47a and 47b act as a guide when the sliding wheel shaft 39 is inserted from the distal end side of the lever portions 45a and 45b.

In other words, when the sliding wheel shaft 39 is inserted between the lever portions 45a and 45b, the sliding wheel shaft 39 is gently guided between the lever portions 45a and 45b, by the inclined portions 47a and 47b. In addition, when the lever portions 45a and 45b are urged inwards towards the sliding wheel shaft 39, the lever portions 45a and 45b are pushed and opened by the sliding wheel shaft 39 while undergoing a elastic deformation. After that, when the sliding wheel shaft 39 reaches the notches 46a and 46b of the lever portions 45a and 45b, these lever portions 45a and 45b approach each other due to the restoring force of the portions lever 45a and 45b. In this way, the lever portions 45a and 45b hold between them the sliding wheel shaft 39 so as to fix this shaft by clipping.

[0055] FIG. 6 is a side view of the tilting lever 40 in its free or natural state (simply called in what follows the free state) before it is mounted on the thinned portion 43. FIG. 7 is an explanatory view showing how the tilt lever 40 in its free state is mounted in the mechanical timepiece (movement 10).

CH 714 615 A2 Here, as shown in fig. 6, the tilting lever 40 in its free state is bent so that the lever portions 45a and 45b form a predetermined angle 0 with the support portion 44.

As shown in fig. 7, when the tilting lever 40 is going to be mounted in the mechanical timepiece 1 (or its movement 10), it is first of all caused that the lever portions 45a and 45b of the tilting lever 40 hold the shaft sliding wheel 39. In other words, the lever portions 45a and 45b are arranged between the sliding wheel bridge 32 and the sliding wheel 34. At this moment, the tilting lever 40 is mounted by these lever portions 45a and 45b so that the support portion 44 moves away from the sliding wheel bridge 32. After that, the tilting lever 40 is forced to undergo an elastic deformation so that the support portion 44 is lifted towards the sliding wheel bridge 32. Then, the support portion 44 is brought into flush with the (in the plane of) lever portions 45a and 45b (see arrow Y1 in fig. 7).

Then, due to the return force of the rocking lever 40, the sliding wheel 34 is pushed towards the rear side (downwards in fig. 7) (see arrow Y2 in fig. 7). Then, the sliding wheel shaft 39, to which the sliding wheel 34 is attached, is also pushed to the rear side. When the sliding wheel shaft 39 is pushed, its head 42 is pushed against the front side surface 32b of the sliding wheel bridge 32. As a result, the friction resistance between the front side surface 32b of the sliding wheel bridge 32 and the head 42 of the sliding wheel shaft 39 is increased.

Operation of the winding force transmission mechanism We will now describe the operation of the winding force transmission mechanism 30 with reference to FIG. 3.

First we will describe the operation during manual arming, also called manual winding.

During manual winding, the winding stem 17 is placed, in the axial direction, in the first winding stem position (step 0) which is the most inward of the movement 10. In the first winding stem position, the winding pinion 24 and the clutch wheel 19 mesh with each other. When, in this state, the winding rod 17 is rotated, the winding pinion 24 rotates by the rotation of the clutch wheel 19. Due to this rotation of the winding pinion 24, the crown wheel 20 meshing with this one turns anticlockwise in fig. 3 (in the direction of arrow Y3 in fig. 3).

Then, meshing with the crown wheel 20, the sliding transmission wheel 33 of the winding force transmission mechanism 30 rotates clockwise in FIG. 3 (in the direction of arrow Y4 in fig. 3). As a result of this, the sliding wheel 34 meshing with the sliding transmission wheel 33 rotates counterclockwise in FIG. 3 (in the direction of arrow Y5 in fig. 3).

Here, the sliding wheel 34 is carried by means of the sliding wheel shaft 39 so as to be tiltable relative to the sliding wheel bridge 32. In other words, the sliding wheel 34 rocks in a direction along which it is moved towards or away from the röchet 14. In addition, when a rotational force is transmitted from the sliding transmission wheel 33, the sliding wheel 34 is biased by this rotational force of so as to move towards röchet 14 (see arrow Y6 in fig. 3).

In addition, the support portion 44 of the rocking lever 40 of the winding force transmission mechanism 30 cooperates in an adjusted and sliding manner with the outer flange 37a of the flange bearing 37. Thus, the sliding wheel 34 moves towards the röchet 14, and the tilting lever 40 follows the sliding wheel 34 by pivoting around the axis C of the support screw 36. As a result, the sliding wheel 34 meshes with the röchet 14 (engagement position). Then, the röchet 14 rotates clockwise in FIG. 3 (in the direction of arrow Y7 in fig. 3). Due to the rotation of the röchet 14, the barrel spring (not shown) housed in the movement barrel 13 is armed.

In the winding force transmission mechanism 30, due to the elastic force of the rocking lever 40, the friction resistance between the front side surface 32b of the sliding wheel bridge 32 and the head 42 of the sliding wheel shaft 39 is increased. Due to this friction resistance, during manual winding, the sliding wheel 34 is held in a position where it meshes with the röchet 14. In other words, during a manual winding operation, the meshing between the röchet 14 and the sliding wheel 34 are not undone, and the manual winding operation is carried out smoothly.

Now we will describe the operation at the time of automatic arming, also called manual winding.

During automatic winding, the winding stem 17 is placed in the first winding stem position (step 0), and the winding pinion 24 and the clutch wheel 19 mesh one with the other.

In this state, a rotational force is applied to the röchet 14 by the oscillating mass via an outer wheel (none is shown). Then the röchet 14 rotates clockwise in fig. 3 (in the direction of arrow Y7 in fig. 3). Due to the rotation of the röchet 14, the barrel spring (not shown) housed in the movement barrel 13 is armed.

CH 714 615 A2 At this time, the rotational force of the röchet 14 is transmitted to the sliding wheel 34 meshing with this röchet 14. Due to this rotational force, a force urging the sliding wheel 34 away from röchet 14 is applied (see arrow Y8 in fig. 3). Thus, the sliding wheel 34 moves away from the röchet 14 and the tilting lever 40 follows the sliding wheel 34 by pivoting about the axis C of the support screw 36. As a result, the engagement between the röchet 14 and the sliding wheel 34 no longer exists (retracted position).

The elastic force of the rocking lever 40 of the winding force transmission mechanism 30 is also exerted in the retracted position (also called the stowed position) of the sliding wheel 34. In other words, resistance by friction is exerted between the front side surface 32b of the sliding wheel bridge 32 and the head 42 of the sliding wheel shaft 39. Thus, during automatic winding, when the sliding wheel 34 is temporarily moved to the retracted position , the sliding wheel 34 is held in this retracted position. Thus, during an automatic arming operation, the röchet 14 and the sliding wheel 34 are not allowed to mesh with each other, and the automatic arming operation is carried out smoothly.

In this way, the winding force transmission mechanism 30 described above comprises the sliding transmission wheel 33 meshing with the crown wheel 20, the sliding wheel 34 meshing with the sliding transmission wheel 33, which is designed to be tiltable around the center of rotation of the sliding transmission wheel 33 (i.e. around the axis C of the support wheel 36) and which moves into position d 'engagement and until in the retracted position, as well as the tilting lever 40 able to retain the sliding wheel 34 in the engagement position and in the retracted position. Means for holding the sliding wheel 34 in the retracted position are made of an elastic member which is the tilting lever 40. Means for holding the sliding wheel 34 in the engaging position are made of this same elastic member, c that is to say of the tilt lever 40.

Thus, during manual winding, the mesh between the röchet 14 and the sliding wheel 34 can be maintained. Thus, it is possible to reduce as much as possible the number of times where noises and shocks are produced during the meshing between the röchet 14 and the sliding wheel 34, which makes it possible to propose a mechanism for transmitting winding force 30 having greater ease of use.

Suppose, for example, that the sliding wheel 34 is constantly biased towards the engagement position or the retracted position. In this case, in one of the armaments among manual and automatic arming, the röchet 14 and the sliding wheel 34 are caused to mesh with each other each time the arming operation takes place. As a result, impacts and collision noises during the meshing between the röchet 14 and the sliding wheel 34 are produced each time the winding operation takes place. In the present embodiment, however, due to the winding force transmission mechanism 30, the sliding wheel 34 is retained in the engagement position or in the retracted position, so that it is possible to reduce as much as possible the number of times noises and shocks are generated during the meshing between the röchet 14 and the sliding wheel 34.

When the röchet 14 is rotated during automatic winding, the röchet 14 and the sliding wheel 34 do not mesh with each other, and this state is maintained. Also, no excess load is applied to the röchet 14, and it is possible to prevent the rotation of the röchet 14 from being transmitted to the sliding transmission wheel 33 and to the crown wheel 20. Thus, it is possible to effectively reduce energy losses during automatic arming.

Even retaining the sliding wheel 34 in the engagement position and in the retracted position, the disc-shaped head 42 equips the sliding wheel shaft 39, fixing the position of the sliding wheel 34, and this head 42 is elastically pushed by the tilt lever 40. As a result, a friction resistance is produced between the sliding wheel bridge 32 and the head 42. By means of this friction resistance, the sliding wheel 34 is maintained in the engagement position and in the retracted position. In this way, the sliding wheel 34 can be kept in the engagement position and in the retracted position by means of a simple constitution, which makes it possible to reduce the size of the winding force transmission mechanism 30 as much as possible. .

The tilt lever 40 is a leaf spring formed from a metal plate having elasticity. In addition, the support portion 44 cooperates in an adjusted and sliding manner with the external peripheral surface of the external flange 37a of the flange bearing 37. Thus, it is possible to place an arrangement producing a friction resistance in the reduced space between the sliding wheel bridge 32 and the head 42 of the sliding wheel shaft 39, and causing the tilting lever 40 to follow the tilting of the sliding wheel 34. Thus, it is not necessary to provide an elastic member for pushing the sliding wheel shaft 39 into each of the two positions which are the engagement position and the retracted position of the sliding wheel 34. Thus, the size of the winding force transmission mechanism 30 can be reduced so More reliable.

In addition, the tilting lever 40 consists of the C-shaped support portion 44 and lever portions 45a and 45b extending from the two ends of the support portion 44. In its free state, the tilt lever 40 is bent so that the lever portions 45a and 45b make a predetermined angle 0 with the support portion 44. This tilt lever 40 is made to undergo elastic deformation so that the support portion 44 and the lever portions 45a and 45b are flush with one another (are in the same plane) to

CH 714 615 A2 the assembly of the winding force transmission mechanism 30. And a friction resistance is produced between the sliding wheel bridge 32 and the head 42.

In this way, it is possible to produce a friction resistance between the sliding wheel bridge 32 and the head 42 by means of a simple construction and in a space-saving manner. In addition, by adjusting the bending angle 0 formed by the support portion 44 and the lever portions 45a and 45b in the free state, the force urging the head 42 towards the sliding wheel bridge 32 can be easily adjusted. In other words, it is possible to easily adjust the amplitude of the friction resistance between the sliding wheel bridge 32 and the head 42. Thus, it is possible to provide a winding force transmission mechanism 30 which is small and easier to use.

The present invention is not limited to the embodiment described above, but includes various modifications thereof within the scope of the invention.

For example, in the embodiment described above, the sliding wheel 34 is retained by the tilting lever 40 both in the engagement position and in the retracted position, relative to the röchet 14. This should not, however, be designed restrictively. It is only necessary that the sliding wheel is able to be retained at least in the retracted position. Because of this constitution, it is possible to reliably reduce energy losses during automatic arming.

In the embodiment described above, the tilt lever 40, which is a leaf spring, is provided as a means for retaining the sliding wheel 34 in the engagement position and in the retracted position. However, this should not be seen as restrictive. It is only necessary that the winding force transmission mechanism 30 be of a constitution allowing the sliding wheel 34 in the engagement position and in the retracted position. For example, instead of the tilt lever 40, a helical spring can be provided in the positions corresponding to the engagement position and the retracted position. Due to the helical spring, the head 42 of the sliding wheel shaft 39 is urged resiliently towards the sliding wheel bridge 32, whereby it is possible that the sliding wheel 34 is retained in the engagement position and in the retracted position.

In addition, in the embodiment described above, the sliding wheel bridge 32 is fixed to the gear train 12, and the sliding transmission wheel 33 and the sliding wheel 34 are supported by this sliding wheel bridge 32 so as to be rotatable. However, this should not be seen as restrictive. It is also possible that the sliding transmission wheel 33 and the sliding wheel 34 are supported by the gear train 12 so as to be rotatable. In this case, the opening 38 of the sliding wheel bridge 32 is formed in the gear bridge 12.

Description of Reference Numbers and Signs [...] 1 ... mechanical timepiece, 10 ... movement, 14 ... röchet, 17 ... winding stem, 20 ... crown wheel,

30.. . winding force transmission mechanism, 32 ... sliding wheel bridge, 33 ... sliding transmission wheel,

34 ... sliding wheel, 38 ... opening, 39 ... sliding wheel shaft, 40 ... tilting lever (means for holding in the back position, means for holding in the engagement position), 41 ... main body d 'shaft, 42 ... head (flanged portion),

44 ... support portion, 45a, 45b ... lever portion, C ... shaft (center of rotation)

Claims (7)

claims 1. Armament force transmission mechanism comprising: a sliding transmission wheel meshing with a crown wheel rotated by an operation of a winding rod, a sliding wheel which meshes with the sliding transmission wheel, which is provided so as to be tiltable around an axis of rotation of the sliding transmission wheel which is movable to a meshing position, in which it meshes with a röchet, and to a retracted position, in which it does not mesh with the röchet, and holding means in the retracted position able to maintain the sliding wheel in the retracted position. 2. winding force transmission mechanism according to claim 1, further comprising means for holding in the engagement position able to maintain the sliding wheel in the engagement position. 3. A winding force transmission mechanism according to claim 2, further comprising a sliding wheel bridge which supports the sliding wheel and which has an opening along a tilting trajectory of the sliding wheel, in which the wheel sliding is fixed to one end of a sliding wheel shaft inserted in the opening, in which, at a proximal end of the sliding wheel shaft through the sliding wheel bridge, there is a flange portion in contact with the sliding wheel bridge, and in which the means for holding in the retracted position and the means for holding in the engagement position are made of an elastic member urging the flange portion against the sliding wheel bridge. 4. A winding force transmission mechanism according to claim 3, in which the elastic member is a leaf spring, one distal end of which lies between the sliding wheel bridge and the sliding wheel, and CH 714 615 A2 one proximal end of the leaf spring being carried so as to be rotatable about an axis of rotation of the sliding transmission wheel. 5. A winding force transmission mechanism according to claim 4, wherein the elastic member has a C-shaped support portion formed to surround a pivot carrying the sliding transmission wheel, and a lever portion extending from the two ends of the support portion to the sliding wheel, the lever portion being resiliently tiltable relative to the support portion, in the axial direction of the axis of the sliding wheel. 6. Movement comprising a winding force transmission mechanism according to one of claims 1 to 5. 7. Mechanical timepiece comprising a movement according to claim 6.