EP3935449B1 - Mechanism for displaying the week number for a timepiece - Google Patents

Description

The subject of the present invention is a mechanism for displaying the number of the week intended to be fitted to a movement of a timepiece.

In general, the mechanisms for displaying the number of the week are arranged to drive a member for displaying the number of the week by one step per week on passing from the last to the first day of the week. The display component is generally carried by a star with 52 or 53 teeth which therefore makes a 1/52nd or 1/53rd turn each week. With this very low angular travel, it can be difficult to ensure the passage of the function in a safe and precise manner. We know, for example, the document CH 711 073 A2 .

The object of the present invention is therefore to produce a mechanism for displaying the number of the week intended to be fitted to a movement of a timepiece which is simple in design but which makes it possible to guarantee the safe and precise passage of the function .

The subject of the present invention is a mechanism for displaying the number of the week according to claim 1, as well as a movement for a timepiece according to claim 12 and a timepiece according to claim 13.

The appended figures illustrate schematically and by way of example only one embodiment of a mechanism for displaying the number of the week according to the invention.

There figure 1 illustrates the mechanism for displaying the number of the week according to the invention during the last day of the week.

There picture 2 illustrates the mechanism for displaying the number of the week according to the invention during the first day of the week.

The week number display mechanism according to the invention is intended to equip a movement of a timepiece. It comprises a week 1 star comprising 53 teeth and carrying a week number display member, preferably a needle (not shown). The week number display member can in particular cooperate with a scale comprising 53 markers and is arranged to advance by one step each week on passing from the last day of the week to the first day of the following week.

In the following, the last day of the week is considered to be Sunday and the first day of the week is Monday (which corresponds to the ISO 8601 standard for the numbering of the days of the week). Of course, other choices are possible (the week starts on Sunday in certain countries and cultures such as in the Hebrew calendar for example).

The week 1 star is driven one step (1/53rd of a turn) per week by a week 2 rocker pivoted on a bridge or the movement plate. The weeks 2 rocker comprises a flexible finger 3 arranged to cooperate with the teeth of the weeks 1 star when the weeks 2 rocker pivots. Preferably, the flexible finger 3 and the weeks rocker 2 came in one piece. A jumper of 13 weeks guarantees the positioning and angular displacement of the star of 1 weeks.

The week rocker 2 further comprises an active end 4, having the shape of an inclined plane in the illustrated embodiment, and intended to cooperate with a driving star wheel 5. Finally, the week rocker 2 is subjected to the action of a return spring 6.

Coach Star 5 is set up to do one round per week. To do this, it can be connected to the movement of the timepiece by an appropriate kinematic chain. The driving star 5 is also arranged to cooperate with the active end 4 of the weeks rocker 2 once a week, on the transition from Sunday to Monday, to cause said rocker to pivot weeks 2 against the action of its return spring 6 and thus rotate the star of weeks 1 by one step via the flexible finger 3 of rocker 2.

According to the invention, the driving star 5 comprises seven teeth, of which six so-called dumb teeth 51 correspond to days 1 to 6 of the week (Monday to Saturday) and are arranged not to cooperate with the active end 4 of the rocker weeks 2. Only the seventh tooth, called the drive tooth 52, is arranged to cooperate with the active end 4 of the weeks 2 rocker to cause said rocker 2 to pivot and thus cause the weeks 1 star to advance by a step. Preferably, the six dumb teeth 51 are the same size (short enough not to get in the way of the active end 4 of the weeks 2 rocker) while the drive tooth 52 is longer to be able to actuate the 4 active end of the 2 week rocker.

Thanks to this trainer star 5 and its particular shape, it is possible to manage easily and efficiently a very low angular stroke of the rocker of 2 weeks.

In the illustrated embodiment, the week number display mechanism cooperates with a day of the week display mechanism. In particular, the drive star 5 is driven one step per day by a day star 7 comprising seven teeth arranged to cooperate both with the dumb teeth 51 and the drive tooth 52 of the drive star 5.

The day star 7 is driven one step per day at or around midnight by a day finger 8 mounted on a drive wheel 9 itself driven at the rate of one revolution per day by the movement of the timepiece. In the illustrated embodiment, the drive wheel 9 is connected to the hour wheel 10 of the movement via a reference 11 and an intermediate wheel 12.

The day star 7 preferably carries a member for displaying the days of the week (not shown), for example a hand. The positioning and movement of the 7 days star is guaranteed by a 71 days jumper.

Preferably, the day finger 8 is arranged to be disengageable, that is to say that it is driven by the drive wheel 9 and actuates the day star 7 when the drive wheel 9 rotates in a first direction ( counterclockwise in the figures), but does not actuate said day star 7 when drive wheel 9 rotates in a second direction (time setting backwards). Traditionally, for such a day finger to be disengageable, it is pivotally mounted on the drive wheel, cooperates with a pin driven into said drive wheel and is subjected to the action of a return spring. Said return spring is fixed at one of its ends to the driving wheel while its other end cooperates with the finger of the days. The return spring is usually attached to the wheel by means of two pins surrounding a screw. However, fixing and guiding the return spring on the wheel are often problematic, particularly given the thinness of the wheel which does not always guarantee sufficient axial hold of the pins or a tapping with a sufficient number of threads for the hold. of the screw.

To solve this problem, the day finger 8 of the illustrated embodiment is pivotally mounted on the driving wheel 9 and comprises a return blade 81 that is monolithic or assembled with said day finger 8. The day finger 8 cooperates with a pin 91 fixed to the drive wheel 9 so that, when said drive wheel 9 pivots in a first direction, counterclockwise in the figures, the pin 91 comes into abutment against the day finger 8 and drives the latter which cooperates with the 7 days star to make it step by step. The return blade 81 is shaped so that, when the driving wheel 9 rotates in a second direction (the clockwise direction in the figures), the return blade 81 comes to cooperate with the pin 91 so that the finger of the days 8 coming to the contact of a tooth of the 7-day star pivots under the action of its return blade 81 without driving said 7-day star while maintaining a position in which it can resume driving the 7-day star , i.e. return in abutment against the pin 91, when the drive wheel 9 resumes its rotation in the first direction.

With the finger of the days 8 according to the present embodiment, the manufacture of the driving wheel 9 is simplified and the assembly of the finger of the days 8 on the driving wheel 9 is facilitated, while ensuring the disengageable function of the finger of the days 8 .

In the illustrated embodiment, the week number display mechanism further comprises a week number correction device operable by a user and comprising a week corrector lever 14 associated with a return spring 15 and arranged to actuate the week 2 rocker and thus advance the week 1 star step by step at the request of a user. The week 2 rocker, in particular its active end 4, together with the week 14 corrector lever are arranged so that when the week 2 rocker is actuated by the week corrector 14 lever, it does not actuate the star trainer 5.

The day of the week display mechanism also preferably comprises a day of the week correction device operable by a user and comprising a day corrector 16 controlled by a lever 17 and subjected to the action of a recall 18. The day corrector 16 is arranged to actuate the day star 7 step by step at the request of a user. During such a correction of the day of the week, the rotation of the day star 7 does not drive the driving wheel 9 since the day finger 8 is disengageable (that is to say that the day finger 8 will pivot against the action of its leaf spring 81 into a position where it is no longer in abutment against the pin 91). In the illustrated embodiment, the day corrector 16 is also arranged to rotate the day finger 8 out of the path of the day star 7 when, during the day of the week correction, the relative position of the day finger 8 and of the day star 7 could lead to a position of buttress between said finger 8 and a tooth of said star 7. Thus, the day corrector 16 makes it possible to guarantee optimum operation and avoid any position of buttress between the finger of days 8 and a tooth of the star of days 7 which could lead to blockage or breakage of the mechanism.

Alternatively, the star of weeks 1 could only include 52 teeth: the years at 53 weeks being very rare, we thus eliminate the need to correct the number of the week every year at 52 weeks, to keep only one correction in rare years at 53 weeks.

In general, the mechanism for displaying the number of the week according to the invention comprises a week star comprising 52 or 53 teeth and intended to carry a member for displaying the number of the week, a rocker of the weeks comprising a finger flexible arranged to cooperate with the toothing of the star of the weeks and a driving mobile arranged to be driven one step per day and to actuate the rocker of the weeks once every seven days on passing from the last to the first day of the week , the flexible finger of said week rocker then cooperating with the teeth of the week star to advance the latter by one step. According to the invention, the driving wheel set is a driving star comprising seven teeth including six dumb teeth which are arranged not to cooperate with the week rocker and one driving tooth arranged to cooperate with said rocker once a week.

Preferably, the six dumb teeth are of the same length and the driving tooth is longer than said dumb teeth.

Preferably, the flexible finger of the week rocker is made in one piece with said rocker.

Preferably, the driving star is driven by a day star comprising seven teeth arranged to cooperate with the mute teeth and the driving tooth of the driving star, able to be driven in rotation by one step per day, and subjected to the action of a day jumper to guarantee its angular positioning.

Other alternatives for driving the driving star are possible: for example, the driving star could be driven by a finger arranged to make one revolution per day. A star with seven teeth mounted integral and coaxial with the driving star and subjected to the action of a jumper could be arranged to make it possible to guarantee the angular positioning of the driving star.

A mechanism for displaying the number of the week is thus produced which is simple in its design but which makes it possible to ensure safe and precise operation despite the low angular travel of the week rocker and of its flexible finger. In addition, the mechanism is easily associated with a day-of-the-week display mechanism as well as with conventional correction devices.

As a variant, it is possible to adapt the display mechanism as described above to allow the display of other information such as the month.

Claims (13)

1. Mechanism for displaying the number of the week intended to be fitted to a
   movement of a timepiece and comprising a starwheel (1) for the weeks comprising 52 or 53 teeth, a rocker (2) for the weeks comprising a flexible finger (3) arranged to cooperate with the toothing of the weeks starwheel (1) upon actuation of said rocker (2) by a driving mobile (5), said one driving mobile (5) being arranged to be driven by one step per day by the movement of the timepiece and to actuate the weeks rocker (2) once every seven days upon passing from the last day of the week to the first day of the week, characterised in that the driving mobile is a driving starwheel (5) comprising seven teeth, of which six teeth are so-called silent teeth (51) which are arranged not to cooperate with the weeks rocker (2) and one tooth is a driving tooth (52) arranged to actuate said rocker (2) once per week upon passing from the last day of the week to the first day of the week.
2. Mechanism as claimed in claim 1, characterised in that it further comprises a
   starwheel with seven teeth subject to the action of a jumper and arranged to cooperate with the driving starwheel (5) to ensure the angular positioning thereof.
3. Mechanism as claimed in claim 2, characterised in that the starwheel with seven teeth is mounted fixedly attached to, and coaxial with, the driving starwheel (5).
4. Mechanism as claimed in any one of the preceding claims, characterised in that it further comprises a starwheel (7) for the days able to be caused to rotate by one step per day by the movement of the timepiece, and subject to the action of a jumper (71) for the days to ensure its angular positioning, the days starwheel (7) comprising seven teeth arranged to cooperate with the silent teeth (51) and the driving tooth (52) of the driving starwheel (5) for driving the latter by one step per day.
5. Mechanism as claimed in any one of the preceding claims, characterised in that the six silent teeth (51) of the driving starwheel (5) are the same length, and in that the driving tooth (52) is longer than said silent teeth (51).
6. Mechanism as claimed in any one of the preceding claims, characterised in that the flexible finger (3) of the weeks rocker (2) is made in one piece with said rocker (2).
7. Mechanism as claimed in any one of the preceding claims, characterised in that an active end (4) of the weeks rocker (2) cooperating with the driving tooth (52) of the driving starwheel (5) has the shape of an inclined plane.
8. Mechanism as claimed in any one of claims 4 to 7, when they depend on claim 4, characterised in that the days starwheel (7) is driven by one step per day by a finger (8) for the days borne by a driving wheel (9) able to be driven at the rate of one rotation per day by the movement of the timepiece.
9. Mechanism as claimed in the preceding claim, characterised in that the days finger (8) is arranged to be disengageable, i.e. it actuates the days starwheel (7) and causes it to advance by one step when the driving wheel (9) rotates in a first direction, but does not actuate said days starwheel (7) when the driving wheel (9) rotates in a second direction.
10. Mechanism as claimed in the preceding claim, characterised in that the finger (8) of the days is arranged to cooperate with a pin (91) fixed in the driving wheel (9) such that, when the driving wheel (9) rotates in a first direction, said finger (8) abuts against the pin (91) in a position in which it can actuate the days starwheel (7); and in that the days finger (8) comprises a return strip (81) which is of one piece with, or assembled with, said days finger (8) and is shaped such that, when the driving wheel (9) rotates in a second direction, the return strip (81) cooperates with the pin (91) such that the days finger (8) - coming into contact with one tooth of the days starwheel (7) - pivots under the action of its return strip (81) without driving said days starwheel (7) whilst staying in a position in which it can resume driving of the days starwheel (7), and thus its position in abutment against the pin (91), when the driving wheel (9) resumes its rotation in the first direction.
11. Mechanism as claimed in any one of the preceding claims, characterised in that it further comprises a member for displaying the number of the week, preferably a hand, borne by the weeks starwheel (1).
12. Movement for a timepiece comprising a mechanism for displaying the number of the week as claimed in any one of the preceding claims.
13. Timepiece comprising a movement as claimed in the preceding claim.

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