CH713437B1 - Jumping display mechanism. - Google Patents

Abstract

The invention relates to a display mechanism jumping by a unit of time for a timepiece comprising a star (1) positioned angularly by a jumper (2) so as to occupy predefined angular positions. The mechanism also comprises: a snail (3) comprising a progressive ascending profile and a steep descending profile and intended to be kinematically linked to the train of a watch movement, a control lever (5) comprising a finger (6) intended to follow the profile of the snail, a winding lever (14) comprising a unidirectional drive system arranged to drive the star (1) in rotation, an intermediate gear kinematically connecting the control lever (5) and the winding lever (14), an elastic return means (20) tending to keep the finger (6) in contact with the snail (3). A rotation of the snail (3) for a unit of time causes a progressive upward movement and an abrupt downward movement of the two rockers (5, 14) and of the intermediate gear, the driving of the star (1) by the rocker of winding occurring during the abrupt downward movement causing the star to rotate between two adjacent predefined angular positions.

Description

Technical area

The present invention relates to the field of watchmaking. It relates more particularly to a jumping display mechanism.

State of the art

We know many watch mechanisms arranged to display a time indication jumping, rather than continuously. The date is the most common of these mechanisms, but other units of time can be displayed in this way, such as for example hours or minutes.

[0003] Application EP2595006 describes such a display mechanism. An hours disc, a portion of which showing the current time appears in an aperture, is rotated discontinuously by a jumping mechanism. In the vicinity of the hour passing, the disc rotates 30 ° to display the next hour number.

However, this type of display has certain drawbacks: the passage of an hour does not take place instantaneously so that it is not possible to know the precise moment of the passage of the hour by observing the evolution of the display. Conversely, not knowing, near the passage of one hour, whether the time display has already changed or not, there may be a doubt about the time reading. This problem is summarized as follows in EP2595006: „There is no simple way for the user to instantly determine whether the jump has already been made or is in progress.“ To solve this problem, a display is proposed. additional in the form of an indicator of the passing state of the jumping hour. However, this solution is not completely satisfactory because it is complex to implement and does not make it possible to solve the problem of the display precision when the hour passes.

The present invention aims to provide a jumping display mechanism which overcomes the aforementioned drawbacks and which is easily adaptable to an existing movement.

Disclosure of the invention

[0006] More precisely, and according to a first aspect, the invention relates to a display mechanism jumping by one unit of time for a timepiece comprising a star positioned angularly by a jumper so as to occupy positions angular predefined. The mechanism also includes: a limaçon comprising a progressive ascending profile and a steep descending profile and intended to be kinematically linked to the cogwheel of a watch movement, a control lever comprising a finger intended to follow the profile of the snail, a winding lever comprising a unidirectional drive system designed to drive the star in rotation, an intermediate gear kinematically connecting the control lever and the winding lever, an elastic return means tending to keep the finger in contact with the snail. A rotation of the snail for a unit of time causes a progressive upward movement and an abrupt downward movement of the two rockers and of the intermediate gear, the star being driven by the winding rocker occurring during the abrupt downward movement causing the star to rotate between two adjacent predefined angular positions.

This arrangement allows the jumping display mechanism of the invention to instantly change the displayed value of the unit of time at the precise moment when this change takes place.

[0008] According to a first variant of the invention, the unidirectional drive system comprises a retractable pusher, movable with reference to the winding lever.

[0009] According to another advantageous variant of the invention, the winding lever comprises an anti-jump device cooperating with the teeth of the star.

This particular arrangement prevents a double jump of the star and reduces the energy consumed by limiting the braking torque of the jumper.

[0011] According to another advantageous variant of the invention, the intermediate train comprises a toothed wheel secured to a retrograde hand displaying a fraction of the unit of time.

[0012] This particular arrangement makes it possible to avoid reading errors in the vicinity of the passage of the unit of time.

[0013] According to another advantageous variant of the invention, the star and the retrograde hand are coaxial.

According to another advantageous variant of the invention, the finger is pivoted on the control rocker which makes it possible not to damage the mechanism if an attempt is made to delay the setting of the time indication

[0015] According to another particular variant of the invention, the unit of time is the hour.

[0016] The invention also relates to a timepiece or a timepiece movement comprising a jumping display mechanism as described above.

Brief description of the drawings

Other details of the invention will emerge more clearly on reading the following description, made with reference to the appended drawings in which: Figures 1, 3, 4, 5, 7, 8, 9 and 10 represent different successive positions of the mechanism during a cycle of one hour, Figures 2 and 6 show the mechanism seen from below, respectively in the positions shown in Figures 1 and 5, FIGS. 11 and 12 represent the mechanism and the minute hand during an hour backing action.

Embodiment of the invention

Figures 1 and 2 respectively show top and bottom views of a jumping hour display mechanism according to the invention, at the start of a cycle just after the passage of one hour. This mechanism is intended to be mounted on a watch movement or integrated into such a movement in order to produce a timepiece such as a wristwatch provided with a jumping time display. In the appended figures, neither the watch movement to which the inventive mechanism relates, nor the display means with which the mechanism of the invention is intended to cooperate are shown for the sake of clarity of representation. Said display means may in particular consist essentially of an hours disc bearing on its periphery the inscription of the hour digits numbered from one to twelve and of a dial provided with a window showing one of the inscriptions of the disc. corresponding to the current time.

The mechanism of the invention comprises firstly a star 1, mounted to pivot about an axis A1 with reference to the movement. This star 1 cooperates in practice directly with the aforementioned display means, and in particular carries, for example, the hour disc so as to cause the latter to pivot with respect to an aperture of the dial. Star 1 has twelve teeth in the shape of wolf teeth, the usefulness of which will appear later. Star 1 is positioned angularly using a jumper 2 coming to rest between two adjacent teeth of star 1, defining for star 1 predefined angular positions corresponding to twelve regularly spaced stable equilibrium positions. thirty degrees.

The input of the mechanism consists of a limaçon 3 in the form of a spiral having a progressive ascending profile and a steep descending profile. The snail 3 is mounted to pivot around an axis A2 with reference to the movement and is kinematically connected to the movement finishing train. To do this, the snail 3 is secured to a pinion 4 engaged with the movement finishing gear and dimensioned so that the snail 3 performs exactly one rotation in one hour.

A control rocker 5 is also pivoted with reference to the movement about an axis A3. The control lever 5 comprises a finger 6 pivotally mounted on the control lever 5 about an axis A4 and whose function is to follow the spiral cam profile of the snail 3. The finger 6 is positioned with reference to the lever control 5 using a stopper and a leaf spring 8. The control lever 5 further comprises a rack.

An intermediate gear 10 is composed of a small pinion 11 engaged with the rack 9, a large pinion 12, integral with the small pinion 11 and a toothed wheel 13 meshing with the large pinion 12. The wheel toothed 13 is positioned coaxially with the star 1, the toothed wheel 13 and the star 1 however not being integral in rotation or coupled to one another.

A winding lever 14 is pivoted on the plate or on a bridge of the movement about an axis A5. The winding lever 14 comprises a toothed sector 15 in engagement with the toothed wheel 13. The winding lever 14 further comprises a retractable pusher 16 pivoted on the lever 14 about an axis A6 and tending to return and remain , under the action of an elastic blade 17, in a thrust position, fixed with reference to the winding lever 14 and defined angularly by a pusher stop 18. The winding lever 14 also includes an anti-winding device. jump 19, the operation of which will be explained later. An elastic return means 20 having the shape of a leaf spring, opposes the rotation of the winding lever 14 in the counterclockwise direction with reference to FIG. 1.

The control lever 5 and the winding lever 14 are kinematically linked by the intermediate gear 10 so that the elastic return means 20 tends to keep the finger 6 in contact with the snail 3 by opposing the rise of finger 6 on the cam of the snail.

The rotation of the snail 3 for a unit of time causes a progressive upward movement and a steep downward movement of the two rockers 5, 14 and of the intermediate gear 10.

The limaçon 3 is driven continuously by the movement and performs clockwise rotations with reference to Figure 1, at an angular speed of one revolution per hour. Figure 3 shows the mechanism about fifteen minutes after the passage of an hour, at the start of the retraction of the pusher 16. The snail 3 has started to gradually lift the finger 6 against the action of the elastic return means 20 which caused a clockwise rotation of the control lever 5, the rotation of the pinions 11, 12 and of the toothed wheel 13 and the counterclockwise rotation of the winding lever 14. The pusher 16 is still in its position. thrust position with reference to the winding lever 14, resting against its stop 18. Under the effect of the rotation of the winding lever 14, the side of the tip of the pusher 16 comes into contact and begins to slide against the flank of a tooth of star 1.

Figure 4 shows the mechanism at the end of the retraction of the pusher 16, about fifty minutes after the passage of the hour. In this position, the levers 5, 14 have continued to pivot and the pusher 16 is about to jump a tooth of the star 1 and to resume its pushing position resting on the stop 18.

Figures 5 and 6 show the mechanism at the end of the progressive upward movement, just before the abrupt downward movement corresponding to the passage of the hour and the fall of the finger 6 from the high level to the low level of the snail 3. The mechanism has accumulated energy thanks to the elastic deformation of the elastic return means 20 during the upward movement of the finger 6 and is about to release it suddenly.

Figures 7 to 10 show different instants of the abrupt downward movement corresponding to the fall of the finger 6 which occurs when the hour passes. Once the finger 6 has left the upper part of the profile of the snail, the two rockers 5, 14 and the intermediate gear 10 accelerate abruptly under the effect of the elastic return means 20. The tip of the pusher 16 strikes a tooth of l 'star 1 and drives it in an anti-clockwise direction with reference to FIG. 7. The action of the push-button continues at least until the position shown in FIG. 8 where a tooth of star 1 exceeds the jumper 2. The finger 6 comes to a stop on the low level of the snail track 3 and the star continues its rotation slightly under the action of the jumper 2 until it reaches a new position of stable equilibrium adjacent to that it. just left. In the display, the change of the hour digit in the window is almost instantaneous. The display mechanism according to the invention thus makes it possible to know the precise moment of the passage of the hour.

The retractable pusher 16 constitutes a unidirectional drive system of the ratchet type, which does not modify the position of the star 1 during the progressive upward movement of the winding lever 14 and which drives the star 1 in rotation counterclockwise with reference to Figure 1, to an adjacent predefined angular position, during the steep downward movement. The wolf-tooth profile of the toothing of star 1 makes it easier to retract the pusher during the progressive upward movement and offers a radial bearing surface perpendicular to the pushing force of the pusher as well as increased resistance shear.

When the impulse given to the star by the pusher, there is a risk that the jumper 2 will allow two teeth to pass instead of just one, which would cause the display to advance by one hour. This phenomenon can appear and increase over time because of the wear of the teeth and the relaxation of the elastic stresses in the jumper 2. It can also result from exceptional circumstances linked to the wearing of the watch. Indeed, the winding 14 and control 5 rockers not being balanced on their axis of rotation, they are sensitive to the movements of the watch. If the watch undergoes a strong acceleration at the precise moment of the passage of the hour, it is possible that the impulse transmitted by the push-button 16 to the star 1 is appreciably stronger than that resulting from the sole release of the elastic return means 20 It is therefore advantageous to provide an additional anti-jump device 19 which secures the advance of the star by preventing a double jump. The anti-jump device 19 consists of a cylindrical portion having an axis of revolution substantially coincident with the axis of rotation of the winding lever 14. When the finger 6 drops and the star is driven via the pusher 16, the anti-jump device 19 is placed between two teeth of star 1, tangentially to the side of a tooth of star 1 as can be seen in FIGS. 7 to 10. If the braking torque of jumper 2 is insufficient to stop star 1 after the passage of a tooth, a tooth of star 1 comes up against the cylindrical surface against the anti-jump device 19 which stops the rotation of star 1 and allows star 1 to return to the equilibrium position that it should not have exceeded.

In the absence of an anti-jump device, there would be no other solution than to increase the force of the jumper 2 and of the elastic return means 20 to secure the advance of the star 1. The anti-jump device 19 therefore also makes it possible to improve the performance of the jumping display mechanism by making it possible to reduce the braking torque of the jumper 2 and the force of the elastic return means 20, and therefore to reduce the energy consumption. .

In one embodiment shown in Figures 11 and 12, the jumping hour display mechanism of the invention is associated with the minute display mechanism by retrograde hand 21, secured to the intermediate gear 10 by the wheel toothed 13. The toothed wheel 13 carries the barrel of the minute hand 21 and is coaxial with the star 1, the axis of the hand passing through a recess in the center of the star 1. The minute hand 21, mounted on the toothed wheel 13, rotates regularly in the clockwise direction during the progressive upward movement then suddenly returns to zero concomitantly with the change of the time display during the abrupt downward movement corresponding to the drop of the finger 6.

In such an embodiment, a difficulty may present itself to the user when the latter wishes to make a correction of the time setting in the counterclockwise direction. Indeed, the jumping hour display mechanism of the invention does not allow the hours display to be returned back but only an incremental adjustment of the hours, by making the hours jump one after the other until reach the correct setting time. Such an adjustment constraint can prove to be particularly tedious when the adjustment to be carried out consists of going back in the current hour, in particular to identify where the last instant of the time jump is located.

To overcome this problem, the latch 5 is advantageously configured so as to include a protuberance in the form of a boss 22 located substantially to the right of the finger 6. After a clockwise jump, the latch 5 drops abruptly and the finger 6 then falls. in a “dead” zone of snail 3, in which it loses contact with said snail. The minute hand 21 is then in position “0”, at its starting point as shown in Figure 11.

If one wishes to adjust the time counterclockwise the user actuates the winder of the movement so that the tip of the snail 3, which is in kinematic connection with the movement finishing cog, moves in counterclockwise until it comes to rest against the boss 22, which causes the lever 5 to rise, causing the needle 21 to rise, as shown in FIG. 12. This rise of the needle 21 constitutes the marker for the user of the last time change in a counterclockwise direction.

The continuation of the rotation of the snail 3 in the counterclockwise direction generates the retraction of the finger 6 which is pivotally mounted on the control lever 5 and is held in position by the leaf spring 8 via the stop 7 resting on this spring 8.

The hand 21 then does not continue its ascent but on the contrary returns to its "0" position as the finger 6 is retracted since the snail 3 is configured to transmit the time information to said hand 21 only in its clockwise movement, which dictates the jumping passage of the hours via rocker 5 and intermediate gear 10. The user then knows that the limaçon 3 travels in the opposite direction the previous 60 minutes without being able to view in direct in which position is the snail 3. In order to be able to precisely adjust the needle 21, it suffices for him to continue the rotation in the opposite direction until the next lifting of the needle 21, which then indicates the end of the course. in the opposite direction and thus reaching the „0“ of the previous hour. It then suffices to resume a normal rotation of the snail clockwise to reach the desired minute setting from this “0” position.

[0039] Advantageously, the display mechanism according to the invention allows a modular construction and can easily be adapted to existing movements. To do this, simply connect the limaçon 3 to the minute wheel of the movement.

[0040] The invention also relates to a timepiece movement comprising a jumping display mechanism as well as to a timepiece comprising such a mechanism.

Those skilled in the art will know how to make multiple variations from the embodiments presented without departing from the scope of the claims. In particular, the unit of time may be different from the hour and the profile of the snail may present several jumps over a lap.

Claims (10)

1. Display mechanism jumping by a unit of time for a timepiece comprising a star (1) positioned angularly by a jumper (2) so as to occupy predefined angular positions characterized in that the mechanism further comprises : - a limaçon (3) comprising a progressive ascending profile and a steep descending profile and intended to be kinematically linked to the train of a watch movement, - a control lever (5) comprising a finger (6) intended to follow the profile of the snail (3), - a winding rocker (14) comprising a unidirectional drive system arranged to drive the star (1) in rotation, - an intermediate gear (10) kinematically connecting the control lever (5) and the winding lever (14), - an elastic return means (20) tending to keep the finger (6) in contact with the snail (3), in that a rotation of the snail (3) for a unit of time causes a progressive upward movement and an abrupt downward movement of the two rockers (5, 14) and of the intermediate gear (10) and in that the driving of the The star (1) by the winding lever (14) intervenes during the abrupt downward movement and causes the rotation of the star (1) between two adjacent predefined angular positions. 2. Mechanism according to claim 1, characterized in that the unidirectional drive system comprises a retractable pusher (16), movable with reference to the winding lever (14). 3. Mechanism according to the preceding claim, characterized in that the winding lever (14) comprises an anti-jump device (19) cooperating with the teeth of the star (1). 4. Mechanism according to one of the preceding claims characterized in that the intermediate gear (10) comprises a toothed wheel (13) integral with a retrograde hand (21) displaying a fraction of the unit of time. 5. Mechanism according to the preceding claim characterized in that the star (1) and the retrograde needle (21) are coaxial. 6. Mechanism according to one of the preceding claims characterized in that the finger (6) is pivoted on the control lever (5). 7. Mechanism according to one of claims 4 to 6, characterized in that the control lever (5) comprises a bearing surface (22), arranged to cooperate with the snail (3) during movement in a counterclockwise direction of said snail (3) so as to induce a lifting of the control lever (5) and a movement of the hand (21) intended to indicate to a user a passage of time in the opposite direction. 8. Mechanism according to claim 7, characterized in that the bearing surface is a boss (22) forming a cam surface such that the control lever (5) pivots clockwise when the snail (3) is supported. on said boss (22) by moving counterclockwise. 9. Timepiece comprising a jumping display mechanism according to one of claims 1 to 7. 10. Timepiece movement comprising a jumping display mechanism according to one of claims 1 to 7.