MANUALLY OPERATED CONTROL MECHANISM FOR CLOCK

Description

[0001] The present invention relates to a control mechanism for a timepiece comprising a manually actuated member from outside the timepiece, a pivoting rocker mounted between a rest position and a tilted position, and a spring arranged to return the rocker to the rest position, the rocker having a first arm arranged to cooperate with the manually actuated member so as to bring the rocker into the tilted position when the member is actuated and having a second arm the end of which is arranged to come directly or indirectly into contact with the teeth of a star or a disc so as to allow it to be driven by actuating the control mechanism. EARLIER ART

[0002] Such mechanisms are well-known. They most commonly serve as correctors, allowing for the gradual advancement of certain indicator components in timepieces. A prime example is calendar watches, where the date, day of the week, or month indicators are very often either hands mounted on stars or discs. A calendar watch can, for instance, be equipped with correctors that allow for the individual adjustment of certain indicators without altering the other displayed time information. The ability to update the indicators of a timepiece independently can prove particularly useful when restarting a timepiece after several days of inactivity.

[0003] On the other hand, during the normal operation of a calendar watch, the date indicators are incremented by the movement at regular intervals. The incrementing of the various indicators is often achieved by fingers, each mounted on a driving wheel and arranged to engage the teeth of a star or disc with each rotation of the driving wheel. It should also be remembered that the date changes at midnight, and therefore it is when the hands of a calendar watch are around midnight that the indicators are incremented by the calendar mechanism. This is why the wearer of a calendar watch should absolutely not attempt to correct the calendar readings at this late hour.Indeed, a calendar indicator mounted on a star or disc cannot move freely during periods when the driving finger intersects the path of the teeth of the star or disc it is meant to drive. It is therefore understandable that if, in an attempt to correct an indicator, a user decides to activate the corresponding control mechanism during one of these periods, the opposing forces exerted by the driving finger and the manually operated part could cause a component of the mechanism to break.

[0004] Several solutions have been proposed to avoid problems when manually correcting the calendar readings at approximately midnight. One known solution is to arrange the finger on the drive wheel so that it can pivot freely concentrically with the wheel itself. A pin driven into the drive wheel's plate then drives the finger. With this arrangement, if one of the calendar readings is manually corrected while the drive wheel finger is in the path of the teeth of the star or disc, the teeth simply push the finger back in the opposite direction to the pin. It is therefore possible to correct the calendar readings forward without risk of breakage. However, this solution is not without its drawbacks. In particular, it causes the finger to become disengaged from the teeth.Document CH 714 372 A2 shows a mechanism for correcting a function of a movement of a timepiece and a corrector included in this mechanism. BRIEF SUMMARY OF THE INVENTION

[0005] One object of the present invention is to overcome the drawbacks of the prior art just described. The present invention achieves this object, as well as others, by providing a control mechanism for a timepiece that conforms to the attached claim 1.

[0006] According to the invention, the second arm is sufficiently elastically flexible to allow the rocker to move into the tilted position when the mechanism is actuated, even if the end of the second arm is held because the rotation of the star or disc is otherwise blocked. Thanks to this feature, a possible blockage of the star or disc does not prevent the first arm of the rocker from pivoting into the tilted position. It will also be understood that a blockage of the star or disc does not affect the travel of the manually operated component. In other words, the same movement performed by a user will advance the star or disc by one step when it is free to rotate, and will simply not advance it if it is blocked. Thanks to this feature, the force exerted by a user on the control mechanism is unlikely to cause any part to break. BRIEF DESCRIPTION OF THE FIGURES

[0007] Other features and advantages of the present invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which: THE figures 1A, 1B et 1C are schematic plan views illustrating three successive stages in the normal operation of a control mechanism conforming to a particular embodiment of the invention; figures 2A, et 2B are views similar to those of the figure 1 illustrating two successive moments in the operation of the same control mechanism when the rotation of the star is blocked by a driving finger. DETAILED DESCRIPTION OF A METHOD OF IMPLEMENTATION

[0008] The schematic plan views in the accompanying figures show a control mechanism conforming to an exemplary embodiment. The control mechanism shown comprises a manually operated control element from outside the timepiece (symbolized by an arrow labeled 1), a rocker (usually labeled 3), and a return spring (labeled 9). In addition to the control mechanism, the figures also show a star (labeled 11) with seven teeth. In this example, the star could carry a day-of-the-week indicator (not shown). The position of the star 11 is indexed by a jumper (labeled 13) which is returned against the teeth of the star by a jumper spring (labeled 15). The figures further show a driving wheel (labeled 17) forming part of a gear train (not shown) which is driven by a motor mechanism (not shown) of the timepiece.In the illustrated example, the gear train is arranged to rotate the drive wheel 17 at a rate of one revolution every 24 hours (clockwise in the drawings). It can be seen that the drive wheel 17 has a driving finger (referenced 19) which is arranged to rotate the star 11 by the angular value of one tooth with each pass.

[0009] The rocker 3 is mounted to pivot about an axis (referenced 21), and it comprises two arms that extend outwards from the pivot axis. The first arm (referenced 5) is the thicker of the two. In the example shown, it has a proximal portion oriented substantially radially with respect to the rocker's pivot axis 21, and a distal portion (referenced 25) with an oblong opening (referenced 27) oriented tangentially with respect to the pivot axis 21. These features give the first arm 5 an approximate T-shape. The second arm (referenced 7) is thinner and terminates in a beak (referenced 23). The beak forms an approximately 90° bend at the end of the second arm. In the illustrated example, the head of a screw (referenced 29) protrudes from the oblong opening 27 made in the distal part 25 of the first arm.It can be understood, firstly, that the oblong shape of the opening 27 allows the screw 29 to slide within the opening when the rocker 3 pivots around the axis 21, and secondly, that the angular position of the rocker is always between a first extreme position in which the screw 29 butts against one end of the opening 27, and a second extreme position in which the screw butts against the other end of the opening. The distal part 25 of the first arm 5 also carries a pin (not shown) against which the end of the return spring 9 rests. The spring 9 is arranged to return the rocker 3 to its first extreme position, known as the rest position. It can be noted that, in the drawings, the direction in which the spring 9 returns the rocker 3 is counterclockwise.

[0010] THE figures 1A, 1B et 1C illustrate three successive stages in the normal operation of the control mechanism that is the subject of this description. In the figure 1A The rocker 3 is in the rest position, while the star 11 is indexed by the jumper 13, which is lowered between two consecutive teeth of the star. In the figure 1B The control mechanism is being activated, and we can see that the rocker 3 is in an intermediate position in which the star 11 has been driven just enough for one of its teeth to have lifted the jumper 13. We can see that at the moment shown, the jumper is balanced on the tip of the tooth. Finally, in the figure 1C , the rocker 3 is in its second extreme position, called the rocker position, while the star 11 has now advanced by the angular value of one tooth and the jumper 13 is again lowered between two consecutive teeth.

[0011] The operation of the control mechanism illustrated in the figures 1A, 1B et 1C is as follows. When the rocker 3 is in its rest position ( figure 1A ) and that a user of the timepiece manually operates the organ 1, he rotates the rocker 3 clockwise against the return spring 9. The beak 23 of the second arm 7 is thus brought to meet one of the teeth of the star 11 and to drive the latter counterclockwise. In doing so, the teeth of the star 11 lift the jumper 13 against the jumper spring 15 ( figure 1B ). Once the jumper 13 has passed over the tip of the star tooth by which it was lifted, it can descend into the next gap under the action of the jumper spring 15 ( figure 1C Finally, when the user releases component 1, the rocker 3 is returned to its rest position by the return spring 9. The control mechanism is then once again in the configuration illustrated by the figure 1A It will be understood in particular that the presence of the jumper 13 ensures that the star 11 advances exactly by the angular value of one tooth each time a user operates the control mechanism.

[0012] As already mentioned, if the control mechanism is activated when star 11 cannot move freely, the force exerted by the user on the manually operated part may cause a component of the mechanism to break. figure 2A This illustrates, by way of example, such a blocking situation. Referring to this figure, we can see that, following the activation of the control mechanism, a tooth of the star wheel 11 became lodged against the end of the finger 19, causing the star wheel to jam before it could advance a full step counterclockwise. It can be seen that any counterclockwise rotation of the star wheel 11 is now impossible. Furthermore, since the star wheel 11 is jammed, it is holding the beak 23 and therefore also the end of the second arm of the rocker arm 3. Under these conditions, if the second arm 7 were rigid, the jamming of the star wheel 11 would necessarily have caused the rocker arm 3 to jam in the position illustrated in the figure. figure 2A Finally, the jamming of the rocker arm would itself have caused the jamming of the manually operated component. It is therefore understandable that if rocker arm 3 was rigid, a user who caused the jamming situation illustrated in the... figure 2A He would not have failed to notice. He might then have made things worse by trying to unblock the mechanism by forcing it.

[0013] According to the invention, the rocker 3 is not rigid since its second arm 7 is sufficiently elastically flexible to allow the first arm 5 to come into a fully rocked position when the mechanism is actuated, even if the beak 23 is held because the star 11 is blocked from rotating. The second arm 7 of the rocker can, for example, essentially consist of a leaf spring that connects the pivot axis 21 to the beak 23. Now, referring to the figure 2B , we can see that the control mechanism is illustrated with the star 11 blocked by the driving finger 19 in a configuration identical to that of the figure 2A Beak 23 also remained unchanged. However, the figure 2B The first arm 5 of the rocker 3 has pivoted clockwise to its second extreme position, known as the tilted position. It can be seen, in particular, that the screw 29 is butted against the corresponding end of the opening 27. It will be understood that the flexibility of the second arm 7 of the rocker makes this configuration possible. Indeed, one can see that, in the figure 2B , the second arm 7 is curved whereas it is straight in the figure 2A Thus, according to the invention, when actuation of the control mechanism prevents the star wheel 11 from advancing by one step because the latter is blocked, the second arm 7 of the rocker can flex to allow the first arm 5 to move into the tilted position as if the mechanism had operated normally. It will be understood that the length of the stroke traveled by the first arm 5 of the rocker 3 is the same in the event of a blockage as in normal operation, and that the same is true for the length of the stroke of the manually actuated component. The user's perception when activating the control mechanism can therefore also be the same.

[0014] Finally, when the control mechanism is in the configuration illustrated in the figure 2B Following its activation by the user and the release of component 1, the return spring 9 returns the rocker 3 to its rest position, so that the beak 23 moves away from the tooth of the star 11 against which it was resting. Since the star 11 is no longer held by the beak 23, it is free to pivot clockwise. Under these conditions, the pressure exerted by one of the two inclined faces of the jumper 13 on the tip of one of the star's teeth may be sufficient to return the star to its initial position. The control mechanism is then again in the configuration illustrated by the figure 1A , without star 11 having been incremented.

[0015] It is also worth noting that the second arm 7 must not be too flexible. Indeed, the second arm 7 of the rocker 3 must have sufficient rigidity to allow it to push one of the teeth of the star 11 with enough force to overcome the holding torque generated by the pressure of the jumper 13 on the star 11 teeth. It will be understood that the second arm of the rocker in a control mechanism according to the invention always fulfills this condition, provided that the jumper spring 15 is not chosen to be too strong.

[0016] It will also be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the embodiments which are the subject of this description without departing from the scope of the present invention as defined by the attached claims.

Claims

1. Control mechanism for a timepiece comprising a member (1) which can be actuated manually from outside the timepiece, a lever (3) mounted to pivot between a first extreme position, referred to as the inoperative position, and a second extreme position, referred to as the tilted position, and a spring (9) arranged to return the lever to the inoperative position, the lever (3) comprising a first arm (5) arranged to cooperate with the manually actuatable member (1) and a second arm (7), the whole being arranged so that the actuation of said member (1) makes it possible to cause the lever (3) to pivot from its inoperative position towards its tilted position and thus to cause the end of said second arm to come directly or indirectly to push one of the teeth of the tooth arrangement of a starwheel (11) or of a disc so as to make it advance by one step, said control mechanism being characterised in that the second arm (7) is sufficiently elastically flexible to enable the lever (3) to pivot from its inoperative position to its tilted position when the mechanism is actuated, even if the end of the second arm (7) is restrained because the rotation of the starwheel (11) or of the disc is otherwise blocked.

2. Control mechanism for a timepiece as claimed in claim 1, characterised in that the timepiece comprises means (13, 15) for indexing the starwheel (11) or the disc, the indexing means (13, 15) being arranged to produce a holding force orientated so as to return the starwheel (11) or the disc towards an indexed angular position when the starwheel or the disc moves away from said angular position, and in that the second arm (7) of the lever (3) has sufficient stiffness to enable it to push one of the teeth of the tooth arrangement of the starwheel (11) or of the disc with sufficient force to overcome the holding force produced by the indexing means (13, 15).

3. Control mechanism for a timepiece as claimed in claim 1 or 2, characterised in that the end of the second arm (7) has a beak (23) arranged to cooperate with one of the teeth of the starwheel (11) or of the disc in order to repel the latter.

4. Control mechanism for a timepiece as claimed in any one of claims 1, 2 and 3, characterised in that the second arm (7) is arranged substantially radially with respect to the pivot axis (21) of the lever (3).

5. Control mechanism for a timepiece as claimed in claims 3 and 4, characterised in that the beak (23) forms a bend of about 90° at the end of the second arm (7).

6. Control mechanism for a timepiece as claimed in any one of the preceding claims, characterised in that the second arm (7) is formed by a spring blade.

7. Control mechanism for a timepiece as claimed in any one of the preceding claims, characterised in that the first arm (5) comprises a proximal part orientated substantially radially with respect to the pivot axis (21) of the lever (3) and a distal part (25) which is pierced by an oblong aperture (27) orientated tangentially with respect to the pivot axis (21), a tenon or a screw (29) fixedly attached to the frame of the timepiece being arranged to slide in the oblong aperture (27) so that the angular position of the lever (3) is always between a first extreme position (referred to as the inoperative position), in which the tenon or the screw (29) abuts against one of the ends of the aperture (27), and a second extreme position (referred to as the tilted position), in which the tenon or the screw (29) abuts against the other end of the aperture (27).