EP3070538A1 - Retrograde display mechanism for a clock movement - Google Patents

Abstract

The present invention relates to a display mechanism for a watch movement comprising a first display unit (66) carrying a first retrograde display member (18) and a retrograde drive device comprising a counting wheel (4) driven by a driving wheel (2), a transmitting mobile (16) cooperating, on the one hand, with the counting wheel (4) and an elastic return member (12), so as to move alternately in a first direction of movement, during a first phase of operation, and in a second direction of movement, opposite, during a second phase of operation, on the other hand, with the first display unit (66), via a first tooth sector. The transmission wheel (16) has at least one additional toothed sector having a kinematic linkage with an additional display wheel (68) for carrying an additional retrograde display member (20), so that display (18, 20) are synchronized.

Description

Technical area

The present invention relates to a display mechanism, for watch movement, comprising a first display unit for carrying a first retrograde display member and a retrograde drive device of the first display member comprising
a counting mobile intended to be driven by a driving mobile of the watch movement,
a cooperating transmission mobile,
on the one hand, with the counting wheel and an elastic return member, so as to be able to move alternately in a first direction of movement, during a first phase of operation, and in a second direction of movement, opposite , during a second phase of operation,
on the other hand, with the first display mobile, via a first toothed sector.

For toothed sector, within the meaning of the present invention, it is necessary to understand any type of toothing, whether it is a rake toothing, a wheel, or even a rectilinear rack.

State of the art

Retrograde type display mechanisms have been known for a long time. By retrograde display mechanism, it is necessary to understand a mechanism for driving a display member, from a starting position, in a first direction of movement during a first phase of operation, then in the opposite direction to during a second phase of operation to bring it back to its starting position. The return to the starting position during the second phase can be achieved with a speed similar to that of the first phase or, alternatively, with a much higher speed (it is called instantaneous return). Furthermore, the displacement may be a rotation or a translation, possibly rectilinear without departing from the scope of the present invention. It is also possible to plan the implementation non-periodic retrograde displays, for example to display the value of a power reserve. In this case, a display member moves in a first direction when the energy source of the watch movement is loaded and in the opposite direction when it is discharged.

Several approaches, in terms of construction, allow to drive a display member following a retrograde movement.

For example, the patent CH 694175 discloses an example of a retrograde display mechanism in which a display needle travels a sector graduated in a first direction of rotation before returning to its initial position by turning in the opposite direction of rotation with the same speed of rotation. This display mechanism involves a cooperation between a cam and a probe forced to follow the periphery of the cam under the effect of the action of an elastic return member. The probe is secured to a toothed sector arranged in engagement with the toothing of a mobile display carrying the display needle.

The patent CH 143441 illustrates a different construction to obtain the same visual result. The mobile display is in this case driven by a transmission mobile having a truncated toothing. When the truncated portion of the toothing reaches opposite the mobile display, the latter is free to be returned to a predefined position, under the effect of the action of an elastic return member.

Display mechanisms arranged to drive a plurality of retrograde display members are also known. The patent application EP 389739 A1 disclose an example. This document describes a watch having four retrograde display hands. A probe is associated with each display pointer, the four probes supported on a single cam to drive the display need in turn. Disclosure of the invention

A main object of the present invention is to propose a display mechanism, for a watch movement, having an alternative construction to the already known constructions and also making it possible to obtain a different display. The display mechanism according to the The present invention can be implemented to realize an animation in a timepiece but, preferably, it can be used to display information, preferably hourly.

For this purpose, the present invention relates more particularly to a display mechanism of the type mentioned above, characterized in that the transmission mobile comprises at least one additional tooth sector, arranged in a plane substantially parallel to that of the first toothed sector. and, having a kinematic linkage with an additional display movable for carrying an additional retrograde display member, such that the display members are synchronized.

As mentioned above, a retrograde display member travels a first path in a first direction of movement, from an initial position to a final position, before traveling the same path in the opposite direction. By "synchronized retrograde display members" within the meaning of the present invention, it should be understood that the display members may have different respective initial and final positions, but occupy them at the same times. Thus, for example, "synchronized display members" having periodic movements would all have the same period.

Thanks to these characteristics, it is possible to provide an indefinite number of retrograde display members in the same timepiece, these having synchronized movements to obtain a novel visual effect. In particular, this feature allows for an unprecedented animation while displaying a time information for example.

According to a preferred embodiment of the present invention, the display mechanism comprises at least one additional toothed sector integral with the first toothed sector and having a kinematic connection with an additional display mobile intended to carry an additional retrograde display member. so that the display members are all synchronized.

Advantageously, it can be provided that the display mobiles are rotatable and coaxial, and that the toothed sectors are defined by the transmission wheel teeth superimposed on the transmission mobile. Such a construction thus has a limited footprint while giving rise to an original display.

In a preferred embodiment, provision may be made for the first display unit to comprise a shaft carrying a toothed wheel, and for the additional display units to comprise hollow shafts, each of which is secured to a toothed wheel. hollow being coaxial with the shaft of the first mobile display and free to rotate relative to each other.

Preferably, it is expected that the respective kinematic links between the transmission wheels and the display mobiles associated therewith involve different respective gear ratios.

From the point of view of the construction of the transmission mobile, it can advantageously be provided that it comprises a central shaft having a shoulder adjacent to a first cylindrical portion and defining a bearing surface against which the transmission wheels are held in axial abutment. , the central shaft comprising a second portion, adjacent to the first portion and having a polarizer, a washer being engaged by a hole of complementary shape on the second portion, so as to be integral in rotation with the central shaft, a third threaded portion being arranged in the extension of the second portion to receive a nut ensuring the locking of the transmission wheels.

The invention also relates to a watch movement comprising a display mechanism meeting the characteristics just described and a timepiece provided with such a watch movement.

Also, thanks to the construction mentioned above, it can be provided, in a preferred embodiment, that the transmission comprises four transmission wheels arranged to drive four display mobiles in a retrograde movement, the timepiece having four retrograde display members associated with the display mobiles and each having substantially the shape of a blade, such that the display members define a fan-shaped structure, with a first phase during which the fan-shaped structure gradually opens up to a configuration of maximum relative spacing between two members adjacent display, and a second phase in which the fan structure closes rapidly to a configuration in which the display members are superimposed.

In general, it is advantageous to provide that the counting mobile comprises a cam and that the transmission mobile comprises a probe arranged to cooperate with the cam and define at each instant the angular orientation of the transmission mobile, the elastic member. being arranged to maintain the probe bearing against the cam at each moment.

In addition, it can also be provided that the cam has an annular shape and is arranged at the periphery of the watch movement.

According to a preferred embodiment, the watch movement comprises a driving wheel arranged in engagement with a toothing of the counting wheel to rotate it in such a manner that the cam makes a turn on itself in twelve hours. cam having twelve identical sectors, the width of which varies continuously between a minimum value and a maximum value and which can successively cooperate with the probe in such a way that each of the display mobiles has a retrograde movement whose period is one hour .

Brief description of the drawings

• la figure 1 représente une vue de face simplifiée d'un mécanisme d'affichage rétrograde selon un mode de réalisation préféré de l'invention;
• la figure 2 représente une vue en perspective éclatée d'une partie du mécanisme d'affichage de la figure 1;
• la figure 3 représente une vue en coupe d'une partie du mécanisme d'affichage de la figure 1, suivant un plan de coupe contenant la ligne III-III de la figure 1, et
• les figures 4a et 4b représentent des vues similaires à la vue de la figure 1, à des stades de fonctionnement différents du mécanisme.

Other features and advantages of the present invention will appear more clearly on reading the detailed description of a preferred embodiment which follows, made with reference to the accompanying drawings given by way of non-limiting examples and in which:

• the figure 1 represents a simplified front view of a retrograde display mechanism according to a preferred embodiment of the invention;
• the figure 2 is an exploded perspective view of a portion of the display mechanism of the figure 1 ;
• the figure 3 represents a sectional view of a portion of the display mechanism of the figure 1 following a sectional plane containing line III-III of the figure 1 , and
• the Figures 4a and 4b represent views similar to the view of the figure 1 , at different stages of operation of the mechanism.

Mode (s) of realization of the invention

The figure 1 represents a simplified top view of a retrograde display mechanism according to a preferred embodiment of the present invention.

In the description which follows, certain elements having no direct impact on the implementation of the present invention will not be described in detail for the sake of clarity.

The display mechanism according to the invention is intended to be combined with a basic watch movement to produce a timepiece having an original display.

A training mobile 2 of the watch movement is visible on the figure 1 it serves as a PTO to operate the retrograde display mechanism.

For this purpose, the driving wheel 2 is arranged in permanent engagement with a counting wheel 4 of the display mechanism. The counting wheel 4 advantageously has a diameter substantially corresponding to the diameter of the watch movement to which the display mechanism is to be assembled. It comprises a crown 6 with internal teeth cooperating with the driving wheel 2, as well as a cam 8 also having a generally annular shape and integral with the crown 6.

The rotational speed of the driving wheel 2 and the gear ratio held between it and the ring gear 6 are such that the counting wheel 4, and therefore the cam 8, turns on itself in twelve hours.

The cam 8 has twelve identical sectors, the width of each of which varies continuously and slowly from a minimum value to a maximum value, while the junction between one sector and the next is relatively steep, or almost in a radial direction.

A feeler 10 is associated with the cam 8, being held in abutment against its periphery under the effect of the action of an elastic return member 12.

The probe 10 is integral with a central shaft 14 of a transmission wheel 16 arranged to transmit the movement of the cam 8 to retrograde display members 18, 20, 22 and 24.

These display members 18, 20, 22 and 24 here each have substantially the shape of a blade and are intended to be pivoted along an axis of rotation 26 with reference to the watch movement.

A bridge 28 is provided to mount the transmission mobile 16 and the display members 18, 20, 22 and 24 directly on a base of the watch movement base.

The figure 2 illustrates the construction of the transmission mobile 16 and allows to better understand the operation.

The central shaft 14 of the transmission unit 16 is pivoted between the stage of the watch movement and the bridge 28.

A cylindrical support portion 32 is provided on the central shaft 14, on the side of the bridge 28, to arrange the probe 10 so that it is integral in rotation with the shaft.

The support portion 32 is adjacent to a shoulder 34, itself being adjacent to a first cylindrical portion 36, followed by a second portion 38 formed by the provision of two flats 40 acting as a polarizer, which is itself followed. a third threaded portion 42 and a pivot 44, arranged at the end of the central shaft 14.

First 46, second 48, third 50 and fourth 52 transmission wheels are engaged on the first portion 36 of the central shaft 14, with the interposition of intermediate washers 54.

An additional washer 56, whose hole has a shape complementary to that of the second portion 38, is arranged against the first wheel 46.

Finally, a nut 58 is put in place, by cooperation with the third threaded portion 42 of the central shaft 14, to flatten the wheels. against the others, with the interposition of the washers 54, and to press the fourth wheel 52 against the shoulder 34, the latter thus acting as a bearing surface for the wheels.

Thanks to this construction, in particular because the washer 56 is integral in rotation with the central shaft 14, the nut 58 can be tightened against it with a sufficiently high torque to guarantee that all the wheels are integral in rotation with each other. the central shaft 14, without rotating the wheels during the clamping operation. Indeed, thanks to the presence of the polarizer, only the axial component of the force exerted by the nut 58 is transmitted to the transmission wheels.

It is also apparent from the illustration of figure 2 that the transmission wheels 46, 48, 50 and 52 do not all have the same diameter.

Indeed, the transmission wheels are arranged in engagement with display mobiles carrying the display members 18, 20, 22 and 24, as it appears more clearly from the figure 3 which is a sectional view along a plane containing line III-III of the figure 1 .

According to the present preferred embodiment of the invention, each transmission wheel 46, 48, 50 and 52 is associated with a display unit 66, 68, 70 and 72.

The first display mobile 66 comprises a shaft whose end 74 is pivoted in the turntable of the watch movement. The shaft carries a toothed wheel 76 arranged in engagement with the first transmission wheel 46.

The second display unit 68 comprises a hollow shaft resting on the wheel 76 of the first display unit 66 and a wheel 78 arranged in engagement with the second transmission wheel 48.

Similarly, the third and fourth display mobiles 70 and 72 comprise hollow shafts resting respectively on the wheels of the second and third display mobiles, while they also comprise wheels 71 and 73 respectively engaged with the third wheels. and fourth transmission wheels 50 and 52.

The fourth display unit 72 is pivoted in a bearing 80 carried by the bridge 28.

Furthermore, each of the shafts of the display mobiles carries the display member 18, 20, 22 and 24 corresponding to its end remote from the watch movement, that is to say the one located on the ice side of the watch. corresponding timepiece.

A nut 82 is screwed onto the free end of the shaft of the first display unit 66 to ensure the axial retention of the display members 18, 20, 22 and 24. A cover 84 is put in place on the nut. 82.

It can be seen that, due to variable wheel diameters, the gear ratios differ between the different transmission wheels 46, 48, 50, 52 and the corresponding display mobiles 66, 68, 70 and 72.

Thus, even though the transmission wheels 46, 48, 50 and 52 are driven together with a single angular speed of rotation, it is otherwise with the display mobiles 66, 68, 70 and 72, and therefore display members 18, 20, 22 and 24 which they carry.

The figures 1 , 4a and 4b illustrate the operation of the display mechanism according to the present preferred embodiment of the invention, which can for example be used to achieve an original display of the current minutes, illustratively non-limiting.

The figure 4a represents the configuration of the display mechanism at the zero minute of each hour; the display members 18, 20, 22 and 24 are then perfectly superimposed.

The cam 8 rotating continuously, because of its cooperation with the driving wheel 2, it has the probe 10 a periphery increasingly close to the center, causing a rotation of the probe 10 in the anti-clockwise direction of rotation.

The rotation of the probe 10 is directly reflected on the transmission wheels 46, 48, 50, 52 which, in turn, cause the display mobiles 66, 68, 70 and 72 to rotate in a clockwise direction this time.

After thirty minutes, the probe 10 has made half of its total path, for a given sector of the cam 8, as well as the display members 18, 20, 22 and 24. However, because of the gear ratios different, the display members 18, 20, 22 and 24 are offset progressively relative to each other and show a partial overlap, as illustrated on the figure 4b .

Thirty minutes later, the final position of the display members 18, 20, 22 and 24 is reached, as shown in FIG. figure 1 .

Compared with the known retrograde display mechanisms, a particular effect is obtained here. Reading the minute is no longer only by reading a discrete position of a display member, here for example the most advanced clockwise corner of the first display member 18, but is more striking being because it is related to the surface covered by the display organs at a given moment.

By way of non-limiting example, the display members here have a total opening of the order of sixty degrees when they are fully deployed.

Note that the display mechanism according to the present invention is preferably associated with a graduated sector carried by a dial not shown here for clarity (or directly on the platen of the watch movement). In addition, other alternatives are of course possible to accurately read the current minute, such as the affixing of a specific index to the free end of one of the display members.

A moment later, the first phase of the forward motion ends, the probe 10 crosses the top of the sector it was traveling and falls into a hollow of the cam 8, turning clockwise, during the second phase of displacement return. At the same time, the display members return to their position corresponding to the zero minute display, as shown in FIG. figure 4a .

Furthermore, the particular construction of the transmission mobile according to the present preferred embodiment of the invention offers an additional advantage because it makes it possible to simplify the adjustment of the display mechanism, in particular the relative angular positions of the organs. display.

Indeed, it may be desirable to have for example all the display members 18, 20, 22 and 24 perfectly superimposed in their positions respective initials. In this case, the probe 10 can be immobilized in the position it occupies when it is located opposite a recessed portion of the cam 8. It is then sufficient to loosen the nut 58 to allow adjustment of the orientations relative to the display members, this setting causing relative rotations of the transmission wheels 46, 48, 50, 52, which is not possible when the nut 58 is tightened. Then simply tighten the nut 58 once all the display members 18, 20, 22 and 24 are superimposed to a satisfactory extent, here in their respective initial positions. A fixed stop may advantageously be provided to identify the initial positions.

The foregoing description attempts to describe a particular embodiment by way of non-limiting illustration and the invention is not limited to the implementation of certain particular features which have just been described, for example the forms illustrated and described for the counting mobile, for the display members and their number, or the structure of the retrograde drive device. Furthermore, the transmission wheels can be replaced by toothed sectors without departing from the scope of the present invention.

Indeed, those skilled in the art will not encounter any particular difficulty in adapting the content of the present disclosure to their own needs and implement a retrograde display mechanism comprising at least two synchronously driven display members, without depart from the scope of the present invention. The implementation of other technical solutions adapted for the implementation of the retrograde drive device has no impact on the present invention. For example, it can be envisaged that the display members travel the return path at the same speed as the forward path or, as described herein in connection with the preferred embodiment, at high speed in a near instantaneous motion.

Claims (12)

Display mechanism, for a watch movement, comprising a first display unit (66) for carrying a first retrograde display member (18) and a retrograde drive device of said first display member (18) comprising
a counting wheel (4) intended to be driven by a driving wheel (2) of the watch movement,
a transmitting mobile (16) cooperating,
on the one hand, with said counting wheel (4) and an elastic return member (12), so as to be able to move alternately in a first direction of movement, during a first phase of operation, and in a second direction of movement, opposite, during a second phase of operation,
on the other hand, with said first display unit (66), via a first tooth sector,
characterized in that said transmission wheel (16) comprises at least one additional tooth sector arranged in a plane substantially parallel to that of said first tooth sector and having a kinematic connection with an additional display wheel (68) for carrying an organ additional retrograde display (20), such that said display members (18, 20) are synchronized. Display mechanism according to claim 1, characterized in that it comprises at least one additional toothed sector integral with said first toothed sector and having a kinematic connection with an additional display unit (70, 72) intended to carry a toothed member. further retrograde display (22, 24) such that said display members (18, 20, 22, 24) are all synchronized. Display mechanism according to claim 1 or 2, characterized in that said display mobiles (66, 68, 70, 72) are rotary and coaxial and in that said toothed sectors are defined by the transmission wheel teeth. (46, 48, 50, 52) superimposed said transmission mobile (16). Display mechanism according to claim 3, characterized in that said first display unit (66) comprises a shaft carrying a gear wheel (76), and in that said additional display mobile (68, 70, 72) comprise hollow shafts, each of which is integral with a toothed wheel (71, 73, 78), said hollow shaft being coaxial to said shaft said first display mobile (66) and free to rotate relative to each other. Display mechanism according to claim 3 or 4, characterized in that the respective kinematic links between said transmission wheels (46, 48, 50, 52) and said display mobiles (66, 68, 70, 72) which are associated involve different gear ratios. Display mechanism according to claim 5, characterized in that said transmission wheel (16) comprises a central shaft (14) having a shoulder (34) adjacent to a first cylindrical portion (36) and defining a bearing surface against which are held in axial abutment said transmission wheels (46, 48, 50, 52), said central shaft (14) comprising a second portion (38), adjacent to said first portion (36) and having a polarizer (40), a washer (56) being engaged by a hole of complementary shape on said second portion (38), so as to be rotationally integral with said central shaft (14), a third threaded portion (42) being arranged in the extension of said second portion (38) for receiving a nut (58) for locking said transmission wheels (46, 48, 50, 52). Display mechanism according to one of the preceding claims, characterized in that said counting mobile (4) comprises a cam (8) and, in that said mobile transmission (16) comprises a probe (10) arranged to cooperate with said cam (8) and defining at each instant the angular orientation of said transmission wheel (16), said elastic return member (12) being arranged to maintain said feeler (10) bearing against said cam (8) at each moment. Watch movement comprising a display mechanism according to one of the preceding claims. Watchmaking movement comprising a display mechanism according to claim 7, characterized in that said cam (8) has an annular shape and is arranged at the periphery of the watch movement. Clock movement according to claim 9, characterized in that it comprises a driving wheel (2) arranged in engagement with a toothing (6) of said counting wheel (4) to rotate it in such a manner that said cam (8) to make a turn on itself in twelve hours, said cam (8) having twelve identical sectors, the width of which varies continuously between a minimum value and a maximum value and, successively able to cooperate with said probe (10) of such that each of said display mobiles (66, 68, 70, 72) has a retrograde movement whose period is one hour. Timepiece comprising a watch movement according to one of claims 8 to 10. Timepiece comprising a movement according to claim 9 or 10, characterized in that said transmission wheel (16) comprises four transmission wheels (46, 48, 50, 52) arranged to drive four display mobiles (66, 68, 70, 72) in a retrograde movement, the timepiece comprising four retrograde display members (18, 20, 22, 24) associated with said display mobiles (66, 68, 70, 72) and each of which has substantially the shape of a blade, such that said display members (18, 20, 22, 24) define a fan-shaped structure, with a first phase during which said fan-shaped structure opens progressively to a maximum relative gap configuration between two adjacent display members, and a second phase in which said fan structure is rapidly closed to a configuration in which said display members (18, 20, 22 , 24) are Bunk.

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