EP3800512B1 - Device for on-demand display for a clock piece - Google Patents

Description

The invention relates to an on-demand display device for a timepiece comprising a cam arranged to be driven by the movement of the timepiece, a retrograde display member, a pinion kinematically connected to the member display, a rake arranged to mesh with the pinion so as to control the display member, elastic means arranged to return the rake and the display member towards a rest position, and a mechanism to manual control comprising a pusher and arranged to control the rake so as to allow the display member to be brought into an indication position from the rest position, the indication position being determined by the current position of drug.

PRIOR ART

We know of display devices which correspond to the definition above. The patent document EP 1 936 448 in particular describes a watch equipped with a device for displaying hours and minutes on demand. The hour and minute hands of this watch have the particularity of remaining stationary opposite the 12 o'clock indication on the dial, as long as the display device has not been activated. The wearer of the watch can cause the hours and minutes to be displayed at any time by pressing a pusher located on the left of the watch case. The hour display and the minute display are implemented in parallel using two very similar mechanisms. The latter each have a snail-shaped cam. These two cams are driven from the ground of the movement respectively at the speed of one revolution in 12 hours and one revolution per hour. The two display mechanisms also include two coaxial gears arranged in the center of the movement and which respectively carry the hour hand and the minute hand. They are also linked to means of reminder arranged so that each of the hands is recalled in the direction of its indication position. The two display mechanisms each include a rack arranged in engagement with the coaxial pinion of the mechanism, so that the hands are slaved to the racks. The latter also each include a feeler arranged to cooperate with the profile of the snail-shaped cam. It will therefore be understood that, when the display device is actuated, the positions in which the hands are respectively placed are determined by the current positions of the cams. It will also be understood that, as the rakes are connected to the return means via the needles, the return means also have the effect of lowering the feelers of the rakes against the two snail-shaped cams.

Each of the actuating mechanisms also includes an actuating lever controlled by the pusher. Each actuating lever is under the influence of a powerful return spring which is arranged to push it back towards the rake, as long as the pusher is not actuated. The pressure of the actuating levers maintains the rakes in their retracted angular positions, in which the feelers are moved away from the snail-shaped cams and the hands positioned at 12 o'clock on the dial. When the wearer of the watch activates the pusher, it causes the two actuating levers to tilt, so that the rakes are free to pivot, and their feelers lower against the profiles of the snail-shaped cams. It will be understood that the snail-shaped cams are dimensioned so that the hour and minute hands come to rest in positions indicating respectively the current hour and the current minute when the rakes are in the active position. Finally, as soon as the pressure on the pusher is released, the actuation rockers return to their initial position, which forces the rakes to pivot again, returning to their retracted angular positions.

In on-demand time display devices like the one just described, the control of the time display takes place strictly manually. The two mechanisms require the hands to follow the movements of the pusher without any delay and without any fancy. Thus, when the wearer of the watch exerts pressure on the pusher, it brings the hands into a position indicating the current time. The current time remains displayed as long as the watch wearer keeps the pusher pressed. Then, when he releases the pusher, it returns to its rest position, while the hands return to rest at 12 o'clock on the dial. One might think that displaying the time on demand would be visually more interesting if the manually operated mechanism were designed to automatically make the hands take some detour when they are operated using the pusher.

The patent document EP 2 615 505 A1 describes a time display mechanism on demand which comprises a timing cam arranged so as to introduce a time difference between the instant when the display of the time is requested and the instant when the indicator hand actually arrives in the indication position. The return of the indicator needle to the rest position also takes place after a predetermined time interval.

The patent document EP 2 159 652 A1 describes a mechanism for displaying the time on demand in which it is necessary to actuate a pusher a first time to cause the time to be displayed, and it is necessary to actuate the same pusher a second time for the indicator hands to return to rest position.

BRIEF STATEMENT OF THE INVENTION

An aim of the present invention is to remedy the disadvantages of the prior art which have just been explained. The present invention achieves this goal as well as others by providing an on-demand display device which conforms to the appended claim 1.

In accordance with the invention, the manually operated mechanism is arranged to, on the one hand, when the pusher is actuated, cause a movement of the display member against the elastic means from the rest position until a predefined position, and on the other hand, when the pusher is then released, allow the elastic means to push the display member from the predefined position towards the rest position. In other words, the display member begins by moving from the rest position to the predefined position, then leaves in the opposite direction, before finally stopping in the indication position. It will be understood that the additional movement associated with the indirect path followed by the display member constitutes a form of animation capable of drawing the eye to the display member of the timepiece.

According to the invention, the on-demand display device comprises a stop rocker which is movable between a retracted position and an active position in which it cooperates with the cam, so that its active position is determined by the position current of the cam. In addition, when the stop rocker is in the active position, it is arranged to interrupt the stroke of the rake when the display member returns from its predefined position towards its rest position, so that the member d The display stops in its indication position. The indication position is therefore determined by the active position of the stop rocker, this active position itself being determined by the current position of the cam. It will also be understood that the indication position of the display member is an intermediate position which is located between the two extreme positions constituted by the predefined position and the rest position.

In accordance with the invention, the display device further comprises timing means arranged to switch the stop switch to retracted position so as to release the display member, so as to allow the return spring to push it back from the indication position to the rest position at a determined instant after the wearer of the coin watchmaker released the pusher. It will be understood that the presence of the timing means allows the display member to remain in the indication position for a certain time even though the wearer has already released the pusher.

BRIEF DESCRIPTION OF THE FIGURES

• les figures 1 à 6 sont six instantanés successifs au cours du fonctionnement d'un dispositif d'affichage à la demande conforme à un mode de réalisation particulier de l'invention.

Other characteristics and advantages of the present invention will appear on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

• THE figures 1 to 6 are six successive snapshots during the operation of an on-demand display device according to a particular embodiment of the invention.

DETAILED DESCRIPTION OF AN EMBODIMENT

THE figures 1 to 6 are six plan views schematically showing the same time display device on demand, at six successive times during its operation. The display device shown conforms to an exemplary embodiment of the invention, and it is intended to be integrated into a wristwatch (not shown). Referring to the figures, it can be seen that the on-demand display device shown comprises a retrograde hand 5 which is arranged to cooperate with a scale graduated from 1 to 12 to indicate the hours (the scale is generally referenced 7) . The figures also show a cam 3 in the form of a spiral with twelve steps, which is arranged to be driven by the movement (not shown) of the timepiece at the rate of one revolution in twelve hours. We can also see a three-arm lever 9 which is part of a manually operated mechanism which also includes a pusher (not shown). Lever 9 is pivotally mounted on an axis 10, so as to be able to selectively occupy an active position ( figure 2 ) when the wearer of the watch presses the pusher, and a rest position ( figures 1 And 3 to 6 ) when the wearer releases the pusher. A return spring (referenced a) is also provided to bias lever 9 towards its rest position. We can further see a rake 11 which is arranged to pivot around an axis 12 and which is kinematically connected to the retrograde needle 5 via a cog formed of a first toothed mobile 15, a intermediate mobile comprising a wheel 19 and a pinion 21, and finally a wheel 13 which carries the needle 5 in the coaxial position. The rake 11 also includes a control arm 17 which is arranged to cooperate with one of the three arms of the lever 9 so that the rake 11 is caused to pivot counterclockwise when the wearer of the watch activates the pusher (not shown) . The figures also show a stop lever 23 which is pivotally mounted on an axis 24 and which comprises a first arm ending in a beak (or feeler) 25 arranged to cooperate with the cam, or hour cochlea, 3 and a second arm 27 arranged to cooperate with the rake 11. The stop rocker is arranged to pivot between a retracted position (illustrated in the figures 1 And 6 ) in which the feeler is kept away from the hour cochlea, and an active, or reading, position (illustrated in the figures 2 to 5 ) in which the feeler 25 cooperates with the cochlea 3. We can finally see a locking rocker 29 pivotally mounted on an axis 30, a locking lever 35 carrying a beak 37, and an unlocking mobile 41 which has the shape of a disc fitted with a finger 43. The unlocking mobile is arranged to be rotated by the movement. The locking rocker 29 is intended to selectively occupy a locked position (illustrated in the figures 1 And 6 ) and an unlocked position (shown in the figures 2 to 5 ). It comprises a nose 31 arranged to cooperate with the stop lever 23, so as to retain the stop lever 23 in its retracted position when the locking lever 29 is itself in the locked position. We can still see that the nozzle 37 of the locking lever 35 is recalled in the direction of the locking rocker 29 by a spring e. The locking lever 29 further comprises a stop catch 33 which is arranged to cooperate with the nose 37 of the blocking lever 35 so as to retain the locking lever 29 in the unlocked position. Finally, in the present example, the unlocking mobile 41 is arranged to be driven at a speed of one revolution per minute (counterclockwise). Once per revolution, the finger 43 of the unlocking mobile pushes the blocking lever 25 so as to release the nose 37 of the catch 33 of the locking lever.

As already mentioned, the device illustrated in the figures has a number of return springs which are only shown in the figure 1 . The five springs illustrated (and referenced respectively a , b, c, d and e) are each represented by a pictogram schematically reproducing the shape of a leaf spring. It will be understood, however, that these springs are not necessarily of the leaf spring type, but can be of any type that those skilled in the art deem appropriate. Referring to the figure 1 , we can see that a first return spring, referenced a (already mentioned), is arranged so as to bias the lever 9 with three arms in a counterclockwise direction so as to return it to its rest position against the pusher (not shown), that a second return spring, referenced b, is arranged so as to return the rake 11 in a clockwise direction, that a third return spring, referenced c, is arranged so as to return the rocker stop 23 in the clockwise direction towards its reading position, that a fourth return spring, referenced d, is arranged so as to return the locking rocker 29 in the clockwise direction towards its locked position, and that a fifth return spring, referenced e (already mentioned), is arranged so as to return the nose 37 of the locking lever 35 towards the locking rocker 29.

We will now explain the operation of the on-demand display device illustrated by referring successively to the different figures. There figure 1 illustrates the display device at rest. The pusher (no shown) is not actuated and the three-arm lever 9 is held in its rest position by the first return spring a. It will be noted that in the rest position, the lever 9 does not interact with the control arm 17 of the rake 11. Under these conditions, the second return spring b keeps the rake 11 completely rotated in the clockwise direction, and we can see that the retrograde hand 5 is immobilized in an off-scale position which is located beyond the indication “12” corresponding to the maximum value of the scale 7 in an arc of a circle. It will be understood that this position which gives no time indication is the “rest” position of the hand 5. In the configuration illustrated by the figure 1 , the lever 9 does not interact with the locking rocker 29 either. Under these conditions, the locking rocker is held in its locked position by the fourth return spring d. It can be seen that in the locked position, the beak 31 of the locking lever 29 retains the stop lever 23 in its retracted position, the feeler 25 then being held away from the hour snail 3. It will be noted that the return spring d is chosen more powerful than the return spring c, so that it has the necessary force to maintain the stop lever 23 in the retracted position.

In accordance with the invention, the manually operated mechanism is arranged to cause a movement of the display member against the elastic means, from the rest position to a predefined position when the pusher (not shown) is activated. Referring now to the figure 2 , we can see that the actuation of the pusher caused the pivoting of the lever 9 with three arms in the clockwise direction against the spring a. By pivoting, one of the arms of the lever 9 pushed back the control arm 17 of the rake 11, so that the latter pivoted counterclockwise (in other words, against the return spring b), and that the retrograde hand 5 is now immobilized in an off-scale position which precedes the indication “1” corresponding to the minimum value of the fixed scale 7. It will be understood that this position which gives no time indication is the “predefined position” of the needle 5.

Always referring to the figure 2 , we can see that another arm of the lever 9 has pushed back the locking rocker 29, so that the latter has pivoted counterclockwise against the return spring d and is now in the unlocked position. As shown in the figure, the arm of the three-arm lever 9 holds the locking toggle 29 in the fully pivoted position, as long as the pusher (not shown) is held down. There figure 2 further shows that following the disengagement of the beak 31 from the locking lever 29, the return spring could return the stop lever 23 to the reading position (with the feeler 25 resting against the profile of the hour snail 3) .

In accordance with the invention, the manually operated mechanism is arranged to allow the elastic means to push the display member from the predefined position towards the rest position when the pusher (not shown) is released. There Figure 3 illustrates the device for displaying the time on demand following the release of the pusher (not shown). It can be seen that, under the action of the first return spring a, the three-arm lever 9 has returned to its rest position by pushing back the pusher. As already explained, when the lever 9 is in its rest position, it interacts neither with the rake 11 nor with the locking rocker 29. It will be understood, however, that the cooperation of the beak 37 of the locking lever 35 with the notch stop 33 of the locking rocker 29 prevents the fourth return spring d from pushing the rocker 29 clockwise. Thus, the locking rocker is retained in its unlocked position and the stop rocker 23 is free to remain in the active position. For its part, the rake 11 pivoted clockwise under the impulse of the return spring b. By pivoting, the rake 11 drove the retrograde needle 5 which also pivoted clockwise.

According to the invention, when the stop rocker is in the active position, it is arranged to obstruct the movement of the rake when the display member returns from its predefined position towards its position of rest, so that the display member stops in the indication position, the indication position of the display member thus being determined by the active position of the stop rocker. Always referring to the Figure 3 , we can see that it is the second arm 27 of the stop rocker 23 which is arranged to be on the trajectory of the rake 11 when the stop rocker is in the active position. In other words, it is the second arm 27 which stops the pivoting of the rake 11 in the clockwise direction. It will also be understood that the exact position in which the needle 5 comes to rest, when the rake 11 abuts against the second arm 27 of the stop rocker 23, is determined by the inclination of the stop rocker. Furthermore, as the stop rocker is in the active position, the feeler 25 is supported against the profile of the hour snail 3, so that it is the current position of the latter which determines the inclination of the rocker stop. The ratio between the lengths of the arms of the stop rocker 23, as well as the profile of the side of the rake 11, are chosen so that the indication position in which the retrograde needle 5 stops, when the rake 11 abuts against the second arm 27, corresponds to the time to be displayed. The needle 5 then remains in its indication position until the locking lever 35 is actuated so as to release the nozzle 37 from the stop notch 33.

In accordance with the invention, the on-demand display device further comprises timing means arranged to, at a determined instant after the wearer of the timepiece has released the pusher, switch the stop toggle to retracted position so as to release the display member, so as to allow the elastic means to push the display member from the indication position to the rest position. As already mentioned, in the example illustrated, the timing means comprise an unlocking mobile which is rotated by the movement. As shown in the figures 4 to 6 , once per revolution of the unlocking mobile 41, the finger 43 pushes the blocking lever 35 so as to make it pivot around its axis 39 against the fifth return spring e. This movement has the effect to release the nozzle 37 from the catch 33. The Figure 4 shows the finger 43 at the moment when it comes into contact with the locking lever 35. The Figure 5 shows the situation a few seconds later. It can be seen that by turning, the finger 43 has forced the locking lever 35 to tilt, so that its nose 37 is now clear of the stop 33 of the locking lever 29, the latter now being free to pivot . It will be understood, however, that at the moment illustrated in the Figure 5 , the return spring d has not yet had time to bring the rocker 29 into the locked position.

There Figure 6 illustrates the display device at the next moment. It can be seen that the locking rocker 29 has pivoted clockwise under the action of the spring d and that it has thus passed into the locked position. The pivoting of the locking rocker caused the nose 31 to lift the stop rocker 23, so that the latter pivoted counterclockwise against the return spring c. In accordance with what has already been explained in relation to the figure 1 , the nozzle 31 now retains the stop lever 23 in its retracted position, and the feeler 25 is therefore away from the hour snail 3. The passage of the stop lever 23 in the retracted position also led to its second arm 27 to move away from the trajectory of the rake 11 which is now free to pivot. We saw that the retrograde needle 5 was kinematically connected to the rake via a gear train. Under these conditions, the rake 11 and the retrograde needle 5 no longer being blocked in the indication position, the retrograde needle 5 has returned to the rest position under the action of the second return spring b .

It will further 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 the present description without departing from the scope of the present invention defined by the appended claims.

Claims (8)

1. On-demand display device for a timepiece comprising a cam (3) arranged to be driven by the movement of the timepiece, a retrograde display member (5), a pinion (15) kinematically connected to the display member, a rake (11) arranged to mesh with the pinion so as to control the display member, elastic means (b) arranged to return the rake (11) and the display member (5) towards an inoperative position, and a manual control mechanism (9) comprising a push-piece and arranged to control the rake (11) so as to make it possible to bring the display member (5) into an indicating position from the inoperative position, the indicating position being determined by the current position of the cam (3); wherein the manual control mechanism (9) is arranged, on the one hand, to cause a displacement of the display member (5) against the elastic means (b) from the inoperative position to a pre-defined position when the push-piece is actuated and, on the other hand, to allow the elastic means to repel the display member (5) from the pre-defined position towards the inoperative position when the push-piece is then released, the display device further comprising a stopping lever (23) which can move between a retracted position and an active position in which it cooperates with the cam (3) so that its active position is determined by the current position of the cam, the stopping lever (23) being arranged to be in the active position and to be an obstacle to the travel of the rake (11) when the display member (5) returns from its pre-defined position towards its inoperative position so that the display member is immobilised in the indicating position, the indicating position of the display member (5) being determined by the active position of the stopping lever (23), the display device further comprising count-down means (35, 37, 41, 43) arranged to switch the stopping lever (23) to the retracted position so as to release the display member (5) so as to allow the elastic means (b) to repel the display member from the indicating position to the inoperative position at a specified time after the push-piece has been released.
2. On-demand display device as claimed in claim 1, characterised in that the rake (11) and the stopping lever (23) comprise contact zones, the profile of the contact zone of the rake being arranged to come to bear against the profile of the contact zone of the stopping lever under the action of the elastic means when the stopping lever is in the active position and the push-piece is released.
3. On-demand display device as claimed in claim 1 or 2, characterised in that it comprises a locking lever (29) arranged to be able to selectively occupy a locked position in which it keeps the stopping lever (23) in its retracted position and an unlocked position in which the locking lever (29) is disengaged from the stopping lever (23), the locking lever being further arranged so as to be elastically returned towards the locked position.
4. On-demand display device as claimed in claim 3, characterised in that the manual control mechanism (9) is arranged to cause the locking lever (29) to pivot from its locked position to its unlocked position when the push-piece is actuated.
5. On-demand display device as claimed in claim 3 or 4, characterised in that it comprises a blocking lever (35) comprising a beak (37) biased against the locking lever (29) so as to make it possible to immobilise this locking lever in the unlocked position.
6. On-demand display device as claimed in claim 5, characterised in that the count-down means (35, 37, 41, 43) comprise a release mobile (41) driven by the timepiece movement and arranged to control the blocking lever (35) so as to release the locking lever (29) at the specified time in order to allow the locking lever to toggle towards the locked position.
7. On-demand display device as claimed in any one of the preceding claims, characterised in that the stopping lever (23) comprises a first arm ending in a feeler (25) elastically biased towards the periphery of the cam (3), the feeler (25) being arranged to cooperate with the cam when the stopping lever (23) is in the active position and to be held away from the cam when the stopping lever is in the retracted position.
8. On-demand display device as claimed in any one of the preceding claims, characterised in that the stopping lever (23) comprises a second arm (27) arranged to be located on the trajectory of the rake (11) when the stopping lever is in the active position and to be located spaced away from the trajectory of the rake when the stopping lever is in the retracted position.

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