CH707439B1 - Anti-retrograde display mechanism for a timepiece. - Google Patents

Abstract

The subject of the present invention is an anti-retrograde display mechanism intended to equip a timepiece, in particular an anti-retrograde display mechanism of the number of the week, comprising an indicator (2) cooperating with a graduation ( 1), the indicator (2) traversing a path between marks A and B of the graduation (1) in a dragging manner or in steps and passing from the marker B to the mark A of the graduation by an instant jump forward, for example by jumping from mark 53 to mark 1 in the case of the anti-retrograde display mechanism of the week number.

Description

Description: [0001] The present invention relates to an anti-retrograde display mechanism for a timepiece comprising an indicator, in particular a pointer, cooperating with a graduation. The present invention relates more particularly to a mechanism for displaying the number of the week.

In addition to the time display, it is usual for a timepiece to include the display of various functions such as moon phases, the time in another time zone, the date, the day of the week not to mention all the functions related to the chronograph. It is obvious that the more the number of functions to display is high plus the construction of the timepiece becomes complex and voluminous and the reading of the information on the dial becomes difficult.

A function less used daily than those listed above but can be very useful in planning and managing delays is the display of the number of the week. Such a display is intended to identify a week in a year. The number of the week is defined in ISO 8601. According to this standard, a year may be fifty-two or fifty-three weeks and the first week of the year is the year with at least four days or the first Thursday of the year. 'year.

[0004] It is known to display some of the functions recalled above in a retrograde manner. A retrograde display is a display in which the indicator does not perform a complete revolution, but only a path from a point A to a point B of a peripheral graduation. Once the measurement is made from A to B, the indicator goes back to point A. However, the retrograde display is a complex mechanism of rack, ratchets and springs that requires very precise design and fabrication.

Anti-retrograde mechanisms, that is to say in which the indicator passes from point B to point A by an instantaneous jump forward are known and in particular in the case of the display of the number of the week .

For example, the document EP 1 982 235 describes a mechanism for displaying the number of the week using the existing minute scale of the timepiece and in which the indicator hand of the number of the week makes a jump. snapshot at the end of the year for the transition from position 53 to position 1 of the minute graduation. To allow this jump forward, the mechanism comprises a hammer cooperating with a cam integral with the wheel bearing the indicator hand of the number of the week and control means for triggering the jump. This solution offers several advantages: a good readability of both the minutes and the number of the week, a saving of space on the dial by reusing an existing graduation, that of minutes, for a new display; and comfort for the user who, thanks to the instant jump at the end of the year, does not need to perform a manual time setting. However, like a retrograde display, the mechanism to perform this jump forward is complex and cumbersome.

The object of the present invention is to provide a timepiece display mechanism that allows the indicator of the display to make one (or more) instantaneous jump forward with respect to the graduation of a determined distance and which is simple and compact.

A particular object of the present invention is to provide a mechanism for displaying the number of the week using the graduation minutes and allowing the number indicator of the week to make an instant jump forward end of year from position 53 to position 1 of the minute graduation and which is less bulky and simpler than known mechanisms.

To do this, the present invention relates to a display mechanism according to claim 1. The invention also relates to a movement and a timepiece provided with such a display mechanism.

In general, the display mechanism according to the invention provides a display in which the indicator travels at least one path between two marks of the graduation and at least one jump forward between two marks of the graduation, the jump being larger than the angular pitch between two consecutive marks of said graduation. In particular, as in the case of a retrograde display, the mechanism according to the invention makes it possible to obtain a display in which the indicator does not go through a complete revolution but only a path from a marker A to a marker. B mark of a peripheral graduation and once the measurement of A to B carried out, returns to the mark A via an instantaneous forward jump. In a preferred embodiment of the invention, the display mechanism is a display mechanism of the number of the week intended to equip a timepiece and comprising an indicator cooperating with the graduation of the minutes of the timepiece to indicate the number of the current week, the indicator passing from the marker 53 to the marker 1 at the end of the year by an instantaneous jump forward.

In addition to its application to display the number of the week, the mechanism of the invention can be used for many displays.

The mechanism according to the invention may also be used to replace a traditional display in which the indicator sweeps, over part of its path, a sector of the dial of the timepiece occupied by a visual element and / or aesthetic such as a decoration worn by the dial or a component of the movement visible through the dial. In this case, the mechanism according to the invention may allow the indicator to jump forward to avoid scanning the sector of the dial in question and thus, not to hide all or part of the visual element.

The invention will be better understood on reading the detailed description of an embodiment of the invention which follows, given by way of example and with reference to the drawing in which:

Fig. 1 is a dial-side view of an embodiment of a display mechanism according to the invention for displaying the number of the week in its initial position.

Figs. 2 and 3 illustrate the mechanism of FIG. 1 in two different positions, the first in which the indicator of the number of the week is opposite the mark 5 of the graduation with which it cooperates and the second in which the indicator of the number of the week is opposite the mark 25 of said graduation.

Fig. 4 illustrates the mechanism of FIG. 1 in its final position, the indicator of the number of the week being opposite the mark of the graduation corresponding to the last week of the year.

Fig. 5 illustrates the return of the mechanism to its initial position after the number indicator has made an instantaneous forward jump between its position shown in FIG. 4 and its position illustrated in FIG. 1.

In the embodiment illustrated in the figures, the display mechanism according to the invention is a display mechanism of the number of the week, said mechanism being seen from above, dial side. This mechanism for displaying the number of the week is intended in particular to equip a timepiece comprising a clockwise display with hands. In particular, the figures illustrate the minute 1 graduation of the timepiece. As illustrated, the graduation minute 1 is carried by the dial (not shown) of the timepiece and is a peripheral graduation composed of sixty pins 1 to 60 also distributed and with which can cooperate in a traditional way a needle of minutes, an hour hand and possibly a second hand (not shown). The positioning of the time display with respect to the movement of the timepiece (in the center or off-center) does not matter and said movement can be mechanical or not.

For ease of understanding, the display mechanism described in the embodiment below is a step display mechanism. More generally, it is obvious that the display mechanism according to the invention can be dragging.

In the illustrated embodiment, the mechanism according to the invention comprises an indicator of the number of the week formed by a pointer hand of the number of the week 2 pivotally mounted coaxially with the axis of rotation of the needle minutes of the timepiece and intended to cooperate with the graduation minutes 1 to indicate the number of the week, said number being between 1 and 53. Preferably and to ensure better readability, the needle 2 will have a form or an aspect that distinguishes it from other needles (minutes, hours, seconds) of the timepiece that cooperate with the minute graduation 1.

The indicator hand of the number of the week 2 is carried by a first wheel 3 pivoted in this embodiment coaxially with the roadway of the movement of the timepiece. The first wheel 3 comprises fifty-two teeth 3a and a toothless sector 3b occupying the place of eight teeth. A second wheel 4 is rotated coaxially to the first wheel 3 and has fifty-three teeth evenly distributed around its circumference. In the illustrated embodiment, the second wheel 4 is placed under the first wheel 3. The reverse is of course possible.

The first and second wheels 3, 4 are free to rotate relative to each other but are nevertheless connected by a spring 6, a first end 6a is integral with the first wheel 3 and a second end 6b cooperates with a pin 7 fixed in the second wheel 4 and passing through a hole 8 made in the first wheel 3. In general, the spring 6, the pin 7 and the light 8 constitute elastic connecting means arranged to connect the first and second wheels 3, 4 with an angular clearance and constrain the first wheel 3 in rotation in the clockwise direction relative to the second wheel 4.

The second wheel 4 is rotated by the movement of the timepiece at a determined speed, in steps per unit of time, which corresponds to a speed of one step per week in this embodiment. The second wheel 4 drives the first wheel 3 by means of a pinion 5 in engagement with each of the first and second wheels 3, 4. Said pinion 5 is arranged to drive the first wheel 3 simultaneously and at the same speed in steps per unit. of the second wheel 4. Thus, each week, the first wheel 3 driven by the second wheel 4 and the pinion 5 takes a step and the indicator hand of the number of the week 2 moves a reference relative to the graduation minute 1. The gear connecting the second wheel 4 to the rest of the movement of the timepiece and allowing its training a step per week is within the reach of the skilled person and will not be described in detail here.

In the illustrated embodiment, the first and second wheels 3, 4 have the same pitch diameter. They have a different module. However, in the example illustrated, the module difference is small and it is possible to play with the tolerances and with the pitch of each of the first and second wheels 3, 4 to allow the meshing of said wheels with a single pinion 5 In this embodiment, the pinion 5 has twenty-five teeth. The module of said pinion 5 must be chosen to allow to mesh simultaneously with the first and second wheels 3, 4. This solution has the advantage of reducing the number of parts and even if it implies a reduction in the efficiency of the gear, this does not really matter in this app.

It is obvious that, in general, the first and second wheels 3,4 could have different diameters and / or be connected by a suitable multiplicative gear which could for example comprise a first pinion engaged with the first wheel 3 and whose module is substantially equal to the module of the first wheel 3 and a second gear engaged with the second wheel 4 and whose module is substantially equal to the module of the second wheel 4, the gear being arranged so that the first wheel 3 it is driven at the same speed in steps per unit of time as the second wheel 4, ie at the speed of one step per week in the illustrated embodiment. Such a multiplicative cog is within the reach of those skilled in the art and will not be described in detail here.

In the illustrated embodiment, the second wheel 4 thus causes each week the first wheel 3 of a step via the pinion 5. However, the number of teeth of the first and second wheels 3,4 is different, each week, the second wheel 4 advance 1/53 of a turn, while the first wheel 3 advance 1 / 60th of a turn. Thus, each week, the second wheel 4 travels an arc larger than the first wheel 3.

In the initial position of the mechanism illustrated in FIG. 1 and corresponding to the first week of the year, the indicator hand of the number of week 2 points to the marker 1 of the graduation minute 1. In this initial position, • said indicator hand of the number of the week 2 is aligned with a tooth of the second wheel 4 which will be named reference tooth 4a in the following and which has been blackened in the figures to facilitate understanding; • the pin 7 is at a first end 8a of the slot 8 of the first wheel 3 and in a position in which the force exerted by the spring 6 on the first wheel 3 and tending to turn the latter in a clockwise direction is the weakest; The first tooth directly following the toothless sector 3b of the first wheel 3, hereinafter referred to as the first tooth 3c of the first wheel 3, is in contact and ready to mesh with the pinion 5.

From this initial position illustrated in FIG. 1, the movement of the timepiece will drive the second wheel 4 and the first wheel 3 via the pinion 5 one step per week. At each step, the reference tooth 4a of the second wheel 4 shifts a little more with respect to the indicator needle of the number of the week 2 carried by the first wheel 3 by taking a step ahead of it, since the second wheel 4 runs 1/53 turn with each step while the first wheel 3 runs 1/60 turn. This offset between the first and second wheels 3, 4 also causes the pin 7 to move in the slot 8: indeed, as for the reference tooth 4a of the second wheel 4 and the indicator hand of the number of the week 2, the pin 7 advances "faster" than the light 8. This shift between the pin 7 and the light 8 causes the winding of the spring 6 which tends to constrain the first wheel 3 in rotation in the clockwise direction. This shift is more particularly illustrated in FIGS. 2 to 4.

FIG. 2 illustrates the mechanism during the fifth week of the year. The second wheel 4 driven by the movement of the timepiece has therefore advanced four steps from its initial position. Simultaneously, the first wheel 3, driven by the pinion 5, has also advanced four steps and the indicator hand of the number of the week 2 now points to the mark 5 of the scale of minutes 1. However, the second wheel 4 has traveled a larger angular path, as shown by the position of the reference tooth 4a of the second wheel 4 relative to the indicator hand of the number of the week 2. The reference tooth 4a of the second wheel 4 is is thus more fully aligned with the indicator hand of the number of the week 2. This shift of the second wheel 4 relative to the first wheel 3 also implies that the pin 7 has advanced in the light 8, away from the first end 8a of said slot 8, and thus arming the spring 6. The force exerted on the pin 7 and the first wheel 3 by the spring 6 is greater than in the initial position of the mechanism.

Fig. Figure 3 illustrates the mechanism during the twenty-fifth week of the year. The second wheel 4 driven by the movement of the timepiece has therefore advanced twenty-four steps from the initial position illustrated in FIG. 1. Simultaneously, the first wheel 3, driven by the pinion 5, has also advanced twenty-four steps and the indicator hand of the number of the week 2 now points to the mark 25 of the graduation minutes 1. The second wheel 4 has nevertheless traveled a larger angular path. The offset between the reference tooth 4a of the second wheel 4 and the indicator hand of the number of the week 2 increases further. As for the pin 7, it still advances in the light 8 by increasing the tension of the spring 6.

Thus, as the weeks go by, the offset between the first and second wheels 3,4 increases and the spring tension 6 also.

FIG. 4 illustrates the mechanism in the last week of the year for a year comprising fifty-three weeks. The second wheel 4 driven by the movement of the timepiece has advanced fifty-two steps from the initial position shown in FIG. 1. Simultaneously, thanks to the pinion 5, the first wheel 3 has also advanced fifty-two steps and the indicator hand of the number of the week 2 points to the mark 53 of the graduation minute 1. The reference tooth 4a of the second wheel 4 has almost returned to its original position. The pin 7 has reached the second end 8b of the light 8 and the spring 6 is forced to its maximum.

In this position, the last tooth of the first wheel 3 before the toothless sector 3b, hereinafter called trigger tooth 3d is engaged with the pinion 5.

As the transition from the last week of the year to the first week of the following year, it would be desirable for the indicator hand of the number of the week to go from marker 53 to marker 1 of the minute scale 1 and this in an instant so as not to disturb the user. Unlike the retrograde mechanism which returns the needle to its initial position by a counterclockwise rotation, the anti-retrograde display mechanism according to the invention allows the passage of 53 to 1 in the clockwise direction.

In the transition from the last week of the year to the first week of the next year, the second wheel 4 pivots a step to resume its original position. Driven by the pinion 5, the first wheel 3 also pivots a step. Thus, the trigging tooth 3d gives way to the toothless sector 3b of the first wheel 3 thus releasing the first wheel 3 of the pinion 5. Under the force of the spring 6, the first wheel 3 then pivots clockwise until that the first tooth 3c of the first wheel 3 comes into contact with the pinion 5 and that the mechanism returns to its initial position as illustrated in FIG. 5. The first wheel 3, the toothless sector 3b, the spring 6, the pin 7 and the lumen 8 are in particular shaped so that this pivoting of the first wheel 3 under the action of the spring 6 returns the indicator needle of the number of the week 2 opposite the mark 1 of the graduation minute 1. Thus, the mechanism according to the invention makes it possible to make the indicator hand of the number of the week 2 a jump forward at the end of the year for go from mark 53 to mark 1.

In the illustrated embodiment, to allow the jump and in particular to allow the release of the first wheel 3, the tripping tooth 3d is truncated. In general, the tripping tooth 3d of the first wheel 3 must be shaped to let out the first wheel 3 of the pinion 5 or of the gear connecting said first wheel 3 to the second wheel 4 at the passage of the last week of the year to the first week of the following year. In particular, depending on the shape of the pinion 5 or the gear connecting the first wheel 3 to the second wheel 4, the tripping tooth 3d must be truncated or not.

The display mechanism of the week number described above with reference to the figures can equip any timepiece including a display of the minute hands, regardless of the position of this display, centered or not. In addition, said mechanism above may be associated with a mechanism for manual or automatic correction of the number of the week for cases where the year has only fifty-two weeks. The said correction mechanism could for example be arranged so that, when the year is only fifty-two weeks old, to make two successive steps to the first and second wheels 3, 4: the first step for the passage from the 52 to the 53 and thus bring the trigger tooth 3d in contact with the pinion 5 and the second step for the jump forward 53 to 1.

For ease of understanding, the display mechanism described in the embodiment above is a step display mechanism. More generally, it is obvious that the display mechanism according to the invention can be dragging.

The mechanism for displaying the number of the week described above thus makes it possible to display the number of the week using the graduation of the minutes. In addition to its small size and simplicity, said mechanism allows a clear, readable and intuitive display of the number of the week. Indeed, this mechanism allows a quick visual interpretation of the position of the indicator hand of the number of the week by analogy with the reading of minutes.

It is possible to generalize the example described in detail above for displaying the number of the week to another display in which the indicator cooperates with a peripheral graduation of n marks separated by a substantially equal angular pitch at 3607k. Note A the first mark of the graduation and B the last mark of the graduation. The indicator does not make a complete turn but goes through n-1 successive steps an arc between A and B substantially equal to (n-1) * 3607k.

In the following, the term "step" is used in general to designate the angular distance traveled by a mobile in a certain time interval (minute, second, day, week, hour, ...) or by a jump be so dragging.

In this general case, the indicator is carried by a first wheel comprising a first toothed sector with n-1 teeth and a second toothless sector occupying the place of m teeth, where m is greater than one and with n 1 + m = k. The mechanism further comprises a second wheel rotated coaxially with the first wheel and having n teeth equally distributed on its circumference. The first and second wheels are free to rotate relative to each other but are connected by elastic connecting means for connecting them with an angular clearance and tending to constrain the first wheel in rotation in a clockwise direction relative to at the second wheel.

The second wheel is driven at a predetermined speed, in steps per unit of time (one step per week / day / hour ...) by a suitable drive train connected kinematically to the movement of the timepiece. The first wheel is driven by the second wheel via a link gear connecting it to said second wheel and arranged to drive said first wheel at the same speed in steps per unit time as said second wheel. At each step of the second wheel, it travels at an angle of 3607n while the first wheel travels at an angle of 3607k, where k = n-1 + m and the indicator moves a mark on the graduation.

We have 360%> 3607k since k = n-1 + m> n with m> 1.

Thus, at each step, the second wheel travels an angular path greater than the first wheel and said wheels are shifted relative to each other, the second ahead of the first. The first and second wheels and the elastic connecting means are arranged so that at each step, the first and second wheels move relative to each other so as to further constrain the first wheel in rotation in the clockwise with respect to the second wheel.

After n-1 step of the second wheel, the indicator carried by the first wheel now points to the mark B. At the next step of the second wheel, the link gear meshing with the last tooth of the toothed sector the first wheel rotates said first wheel clockwise so that the toothless sector of the first wheel co-operates with the connecting gear. The first wheel, which is no longer held by said linkage gear, then rotates clockwise under the action of the elastic connecting means until the toothed sector of the first wheel returns to contact with the gear link. The indicator carried by said first wheel has therefore made an instantaneous forward jump to move from the B mark to the A mark.

In the detailed example described above for displaying the number of the week using the graduation of the minutes, one = 53 m = 8 k = 60 A is the mark 1 of the graduation of minutes, B is the mark 53 of the minute graduation.

In general, the A mark does not necessarily indicate the starting point of the graduation (0 or 1 for example) and the B mark does not indicate the end of the graduation, but these marks may designate any pair of marks. consecutive in the graduation.

As already mentioned above, the first and second wheels may have different pitch diameters and the appropriate drive train capable of driving the second wheel at the desired speed, in steps per unit time, (one step). parsemaine / mois / heure ...) as well as the appropriate link gear capable of driving the first wheel at the same speed in steps per unit of time and simultaneously with the second wheel are within the reach of those skilled in the art . The above embodiment has been described by way of example only. Alternatively, the mechanism could be arranged so that the indicator makes several paths in steps or trailing each interspersed with a jump forward, said jumps can be of equal or variable amplitude. For example, the indicator could travel a first path between the A and A1 marks and then jump forward between the A1 and A2 marks, then travel a second path between A2 and B and return to the A mark by another jump forward. between B and A, the jumps between A1 and A2 or B and A may be of the same amplitude or not.

In general, the display mechanism according to the invention is intended to equip a timepiece and comprises an indicator arranged to cooperate with a graduation, the position of the indicator with respect to this graduation being significant of the function to display.

The display mechanism further comprises a first mobile bearing the indicator and having at least one toothed sector and at least one toothless sector occupying the place of at least one tooth.

The display mechanism according to the invention further comprises a second mobile coaxial with the first mobile, free in rotation relative to the first mobile and arranged to be driven by the movement of the timepiece at a determined speed, in steps per unit of time.

The display mechanism according to the invention further comprises a link gear connecting the first mobile to the second mobile and for driving said first mobile simultaneously and at the same speed in steps per unit time that the second mobile .

The second mobile is further connected to the first mobile by elastic connecting means for connecting the first and second mobiles with an angular clearance greater than or equal to the angular distance of the toothless sector of the first mobile and arranged to constrain the first mobile in rotation clockwise.

The second mobile has an angular pitch strictly greater than the angular pitch of any toothed sector of the first mobile, so that at each step of the first and second mobiles (driven simultaneously via the link gear), the second mobile traverses an angular path bigger than the first mobile. Thus, at each step, the second mobile moves relative to the first mobile, the elastic connecting means ensuring the angular play between said mobile and constraining the first mobile rotation in the clockwise direction relative to the second mobile, so that, when a toothed sector gives way to a toothless sector of the first mobile, said first mobile is rotated clockwise by the elastic element and the indicator makes an instantaneous jump forward with respect to the graduation of an angular distance which corresponds essentially to the angular distance of the toothless sector.

Thus, an "anti-retrograde" display mechanism is provided which offers numerous advantages because of its simplicity and small size and which allows a wide variety of applications, in particular the clear and readable display of the number of the week.

Claims (7)

claims 1. Anti-retrograde display mechanism for equipping a timepiece comprising a movement, the anti-retrograde display mechanism comprising: an indicator (2) arranged to cooperate with a peripheral graduation (1) belonging to the piece timepiece or said anti-retrograde display mechanism, the position of the indicator (2) with respect to this peripheral graduation (1) being significant of the function to be displayed, • a first mobile (3) bearing the indicator (2), having at least one tooth sector (3a) and at least one toothless sector (3b) occupying the place of at least one tooth, • a second mobile (4) coaxial with the first mobile (3), free in rotation relative to the first mobile (3) and arranged to be driven by the movement of the timepiece, and • a link gear (5) arranged to allow the driving of the first mobile (3) by the second mobile ( 4) at the same speed, in no time r time unit, and simultaneously with said second mobile (4); characterized in that the second mobile (4) is further connected to the first mobile (3) by elastic connecting means (6, 7, 8) arranged to constrain the first mobile (3) in clockwise rotation by relative to the second mobile (4); in that the second mobile (4) has an angular pitch strictly greater than the angular pitch of any toothed sector (3a) of the first mobile (3), so that at each step of the first and second mobiles (3, 4) the resilient connecting means (6, 7, 8) are reinforced, so that when a toothless sector (3b) of said at least one toothless sector (3b) of the first movable (3) co-operates with the linkage gear (5), said first mobile (3) is rotated clockwise with respect to the second mobile (4) under the action of the elastic connecting means (6, 7, 8) which disarm and the indicator (2) jumps with respect to the peripheral graduation (1) which essentially corresponds to the angular distance of said toothless sector (3b). 2. anti-retrograde display mechanism according to claim 1, characterized in that the peripheral graduation (1) belongs to the anti-retrograde display mechanism and comprises n pins separated by an angular pitch substantially equal to 3607k; in that the first mobile consists of a first wheel (3) comprising a toothed sector (3a) with n-1 teeth and a toothless sector (3b) occupying the place of m teeth, where k = n-1 + m; and in that the second mobile is constituted by a second wheel having n teeth, where n and m are integers greater than 1. 3. An anti-retrograde display mechanism according to claim 2, characterized in that n is equal to 53 and m is equal to 8, the anti-retrograde display mechanism thus making it possible to display the number of the week. 4. anti-retrograde display mechanism according to one of claims 2 and 3, characterized in that the first and second wheels (3, 4) have the same pitch diameter and the angular pitch of each of the wheels is adapted to allow simultaneous driving of said wheels by a single mobile (5) forming said linkage gear. 5. anti-retrograde display mechanism according to one of the preceding claims, characterized in that the elastic connecting means consist of an elastic element (6), a first end (6a) is fixed to the first mobile (3). ) and a second end (6b) cooperates with a pin (7) carried by the second mobile (4) and passing through an opening (8) of the first mobile (3), the elastic element (6) being arranged to constrain the first movable (3) in rotation clockwise with respect to the second movable (4) and the opening (8) extending over an angular distance greater than or equal to the angular distance of the largest toothless sector (3b) from the at least one toothless sector (3b) of the first mobile (3). Clock movement with an anti-retrograde display mechanism according to one of claims 1 to 5. 7. Timepiece provided with an anti-retrograde display mechanism according to one of claims 1 to 5.