HK1144842B - Device that assists in maintaining the position of a date indicator disc for a timepiece - Google Patents

Description

Device for assisting in maintaining the position of a date indicator disc for a timepiece

Technical Field

The present invention relates to a device for helping to maintain the position of a date indicator disc for a timepiece.

Background

One exemplary embodiment of a date indicator mechanism is shown in the perspective view of FIG. 1, which is attached to this patent application. A mechanism of this type, generally designated by the general reference numeral 1, is intended to be mounted in the bottom plate (bottom plate) of a watch (not shown), usually a wristwatch), to display the date of the month. Date mechanism 1 comprises a top date ring 2 and a bottom date ring 3. Top date ring 2 is superimposed on bottom date ring 3. Top date ring 2 is regularly distributed with sixteen sectors on its circumference. These sixteen sectors comprise successive markings "17" to "31" on the upper surface of ring 2 and a window 21, which in the example shown is a through hole arranged in top date ring 2. The bottom date ring 3 is also regularly distributed with sixteen sectors on its circumference. These sixteen sections include successive markings "1" to "16" on the upper surface of the ring 3. The watch typically has an opening through which the indicia on top date ring 2 and bottom date ring 3 are visible.

Fig. 2 and 3 show more in detail the constituent parts of top date ring 2 and bottom date ring 3. Teeth 22 project radially towards the inside of top date ring 2 from an inner periphery 23 of top date ring 2. Similarly, tooth 32 protrudes radially towards the inside of bottom date ring 3 from inner periphery 33 of bottom date ring 3. Teeth 22 and 32 are regularly spaced along inner peripheries 23 and 33 of date rings 2 and 3, respectively. Each tooth 22 is associated with a marking 24 or window 21 of top date ring 2. Similarly, each tooth 32 is associated with a marking 34 of bottom date ring 3.

Date indicator mechanism 1 also comprises a control wheel 4 for driving top date ring 2 and bottom date ring 3. The control wheel 4 completes one revolution in 31 days. The control wheel 4 is driven by a pinion 61 on the hour wheel and by gears 62 and 63, which will not be described further here.

Fig. 4, which is attached to the present patent application, is a detailed perspective view of the control wheel 4. As best shown in fig. 4, the control wheel 4 has first and second stacked layers of ring gears 41 and 42. Each of the ring gears 41 and 42 has on its periphery a portion fitted with continuously adjoining teeth and a portion without any teeth. The teeth are regularly spaced at an angle of 2 pi/31 at the respective toothed portions of the first and second-layer ring gears 41 and 42.

As shown in fig. 4, each tooth of toothed rings 41 and 42 is marked with a reference number to indicate which sector of top date ring 2 and bottom date ring 3 it controls. First-tier toothing 41 thus comprises teeth controlling sections "17" to "31" of top date ring 2 and window 21. The portion of the first-layer toothing 41 without teeth therefore extends between the teeth of the control section corresponding to the window 21 and the teeth of the control section "17". Second-tier ring gear 42 includes the teeth of control sections "1" through "16". The portion of second-tier ring gear 42 without teeth therefore extends between the teeth of control section "16" and the teeth of control section "1". The portion of one layer having teeth is disposed perpendicular to the portion of the other layer having no teeth. Thus, the teeth of the first-layer ring gear 41 that control the marks "17" to "31" of the top ring 2 are arranged perpendicular to the portion of the second-layer ring gear 42 that does not have teeth. The portion of the first-layer ring gear 41 without teeth is perpendicular to the teeth of the second-layer ring gear 42 that controls the marks "2" to "16" of the bottom ring 3. In particular, the teeth of first-level toothing 41, which control sector "1" of bottom date ring 3, are arranged perpendicularly to the teeth of second-level toothing 42, which control the sector corresponding to window 21 of top date ring 2.

First and second-tier toothed rings 41 and 42 are coupled in rotation so that a simple rotation of control wheel 4 in one revolution drives one or the other of both top date ring 2 and bottom date ring 3. First and second ring gears 41 and 42 are arranged to drive top date ring 2 and bottom date ring 3, respectively, through their toothed portions. Multiplier (multiplier) wheel sets 11, 13 form respective kinematic connections between first and second layers of toothed rings 41 and 42 and top and bottom date rings 2 and 3. Multiplier wheel sets 11 and 13 ensure that a daily rotation of control wheel 4 means that a date ring moves one step forward from one date in the month towards the next.

Fig. 5, to which this patent application is attached, is a side view of the date indicator corrector mechanism, as shown in which a first-tier ring gear 41 is kinematically coupled to a top date ring 2 by a first multiplier gear set 11, a third multiplier gear set 13 and a top gear of a corrector gear train 9. Multiplier gear set 11 includes a pinion gear 112 driven by the toothed portion of first-tier ring gear 41. Multiplier gear set 11 also includes a wheel 111 secured to pinion gear 112. Multiplier gear set 13 includes a pinion 131 driven by wheel 111. Multiplier gear set 13 also includes a wheel 132 fixed to pinion 131 and driving the top gear of corrector gear train 9.

During the rotation of the control wheel 4, the operation of the date indicator mechanism 1 is as follows. It is assumed that the window 21 and the indicia "1" are initially located below the opening in the watch. Thus, the person wearing the watch can see the first day of the month. When a change is made from the first to the second, then from the second to the third of the month, and so on, under the control of the control wheel 4, up to "16":

the portion of first-layer toothing 41 without teeth is opposite first wheel set 11. Thus, top date ring 2 is not actuated, and window 21 remains stationary and is located below the opening of the watch;

the teeth of second-tier toothing 42, which control the movement of the marks "2" to "16", will successively mesh with second multiplier gear set 12, driving bottom date ring 3 through teeth 32 of bottom date ring 3. Thus, the dates "2" to "16" are displayed successively in the opening of the watch through the window 21.

When changing from date "16" of the month marked on bottom date ring 3 to date "17" of the month marked on top date ring 2, and then changing in sequence from date "17" to "31", under the control of wheel 4:

the portion of the second tier ring gear 42 without teeth is opposite the second multiplier gear set 12. So that bottom date ring 3 is not driven and date "16" remains stationary below the opening;

the teeth of first-tier toothing 41, which control the movement of the marks "17" to "31", will successively engage with wheel set 11, driving top date ring 2 through teeth 22 of top date ring 2. Thus, dates "17" to "31" will be displayed in succession in the opening.

When the date "31" carried by the top ring 2 is changed to the date "1" carried by the bottom ring 3, the teeth of the first-layer toothing 41 controlling the movement of the window 21 and the teeth of the second-layer toothing 42 controlling the movement of the indicia "1" mesh simultaneously with the wheel sets 11 and 12, respectively, with the teeth of the first-layer toothing 41 superposed on the teeth of the second-layer toothing 42. Thus, top date ring 2 pivots to place window 21 below the aperture, while bottom date ring 3 pivots to place indicia "1" below the aperture.

As can be seen from a study of fig. 1, the position of top date ring 2 and bottom date ring 3 is indicated by a jumper spring 50, which jumper spring 50 is held by a spring 51. This jumper spring 50 serves to hold date rings 2 and 3 in position and prevent these date rings from undesired rotation due to the action of, for example, shocks, other than during the correction of the date indication. When one wishes to obtain a date mechanism with a jump duration that is as short as possible, the multiplication ratio between the relevant control wheel and the date ring must be as high as possible. The torque available at the output of the gear train connecting the control wheel to the date ring is therefore low, so that the force exerted by the jumper spring on said date ring must be as small as possible in order to be overcome when moving the date ring one step forward. However, if the retention force exerted by the jumper spring on the date ring is low, there is a serious risk of jumping the date ring in the event of shocks and incorrect date indication.

Disclosure of Invention

The present invention aims to overcome these and other drawbacks by providing a date indicator mechanism having a high level of shock resistance outside the date indicator correction period, and only a low resistance torque during the date indicator correction phase.

The invention therefore concerns a device for assisting in maintaining the position of a date-indicator disc for a timepiece, the position of which is marked by a jumper spring, said device being characterized in that it comprises a locking member which keeps the jumper spring locked except during the correction of the date indication, and said locking member is moved aside during the correction of the date indication in order to release the jumper spring.

Thanks to these features, the invention provides a date indicator mechanism whose date disc remains locked outside the date indication correction phase, is released during the date indication correction phase and remains marked by a jumper spring. Thus, it is ensured that during normal operation of the watch, the date indicator disc is held firmly and is not prone to undesired pivoting under the effect of, for example, shocks. Thus, the date indication provided by the watch equipped with the date mechanism according to the invention is always reliable. However, when the date indication has to be changed near midnight, the date disc is held only by the jumper spring with low resisting torque. Thus, the available torque at the output of the gear train connecting the control wheel to the date ring does not need to be very high, so that the multiplication ratio between the control wheel and the date ring can be large. A date mechanism having a faster jump than the drag mechanism and close to the instantaneous jump mechanism is thus obtained.

According to a supplementary feature of the invention, in the date-indication correction phase, the locking member is moved away from the jumper spring locking position of the locking member by an actuating member, which is in turn driven by a gear train kinematically connecting the control wheel and the date-indicator disc.

Thanks to this feature, the jumper spring is released from its locking position only at the moment when the date indication corrector train starts to operate, which occurs only once during a very short period of time close to midnight every twenty-four hours and during the manual date correction phase. Thus, for most of the time, the date disc is preferably stationary and is therefore less prone to undesired jumps in the case of, for example, shocks.

According to a further feature of the present invention, the locking member is locked between the jumper spring and the actuating member outside the date indication correction phase.

Drawings

Other characteristics and advantages of the invention will appear more clearly from the following detailed description of an embodiment of the date mechanism according to the invention, given as a non-limiting example only with reference to the accompanying drawings, in which:

FIG. 1, to which reference has been made, is a perspective view of an exemplary embodiment of a date indicator mechanism;

FIG. 2, already referenced, is a perspective view of the top date ring;

FIG. 3, already referenced, is a perspective view of the bottom date ring;

FIG. 4, to which reference has been made, is a perspective view of the control wheel;

FIG. 5, to which reference has been made, is a side view of a multiplication mechanism coupled to a control wheel;

FIG. 6 is a perspective view of the date indicator mechanism shown in FIG. 1 equipped with a locking device according to the present invention; and

fig. 7A to 7F illustrate the operating principle of the locking device according to the present invention.

Detailed Description

The invention proceeds from the general inventive idea of taking into account the two objects that at first sight appear to be contradictory, namely providing a date mechanism whose date-indicator disc is held firmly in order to prevent it from pivoting in the event of shocks and to provide incorrect date indications, while having the lowest possible resisting torque during correction, so that it can be moved forward by one step in a shorter time due to the gear train having a higher multiplication ratio. These two objectives are achieved by using a member that: this member locks the date indicator disc by acting on the jumper spring of the date indicator disc outside the date indication correction period. The member is moved away from the position where the member locks the date indicator plate during the time that the date indication is corrected.

The invention is described below in connection with a date indicator mechanism comprising two superposed date discs. It goes without saying that the invention can be applied in the same way to a date-indicator mechanism having only one date-indicator disc divided into 31 sectors, on which date indications from "1" to "31" are marked.

For the sake of clarity, the locking mechanism according to the invention will be described in connection with the top date ring 2. Obviously, the locking mechanism associated with bottom date ring 3 is the same as that of top date ring 2.

As described above, top date ring 2 and bottom date ring 3 are kinematically connected to control wheel 4 by a date indication correction train comprising multiplier wheel sets 11, 13 and 12, 14, respectively, and corrector wheel set 9. More specifically, top date ring 2 is driven by first-level toothed ring 41 of control wheel 4 via first multiplier wheel set 11, third multiplier wheel set 13 and the top gear of corrector wheel set 9. Multiplier gear set 11 includes a pinion gear 112 driven by the toothed portion of first-tier ring gear 41. Wheel 111, coaxially fixed to pinion 112, drives pinion 131 of third multiplier wheel set 13. Finally, wheel 132, coaxially fixed to pinion 131, drives the top gear of corrector wheel set 9, which in turn drives top date ring 2. As can be seen from a study of fig. 6, the position of top date ring 2 is indicated by jumper spring 50, which jumper spring 50 is held by an arm 51a of spring 51.

People are seeking to obtain the most rapid date indication jump possible from one given date to the next. Therefore, via first multiplier wheel set 11, third multiplier wheel set 13 and the top gear of corrector wheel set 9, the multiplication ratio between control wheel 4 and top date ring 2 must be as high as possible. Assuming this condition is met and the angle of the two date steps is 22.5-which is the value for the date indicator mechanism for the two discs-then the date change occurs in about 40 minutes. This is the conventional jump period of a semi-instantaneous date indicator mechanism with a single disc, which is reduced to 20 minutes thanks to the present invention. Thus, the date mechanism of the present invention can be ascribed to the type of semi-instantaneous date mechanism between the drag-type date mechanism and the instantaneous date mechanism. Thus, a date mechanism can be obtained in which the date change is faster than in the past by making the date indication correction train wheel to an appropriate size, but as a result the torque available at the tip of the correction train wheel of the top gear of the corrector wheel set 9 is small. It is therefore necessary to select a jumper spring 50 that exerts a sufficiently weak retaining force on top date ring 2 so that it can be overcome by the top gear of corrector wheel set 9 during the date indication correction phase. It will be readily appreciated that in this case the retaining action exerted by jumper spring 50 on top date ring 2 is not entirely reliable, with a serious risk of date ring jumps in the event of large shocks.

The object of the present invention is to overcome this problem by providing a device that helps to maintain the position of the date ring, which ensures good shock resistance of the date ring in the normal operating phase of the watch, i.e. outside the period in which the date indication is corrected, while allowing the date indication to be corrected with a minimum of torque. Thus, the present invention teaches the addition of a locking member to the date indicator mechanism. The locking member keeps the jumper spring locked except during the date indication correction period, and moves away to release the jumper spring in the date indication correction period. In the exemplary embodiment shown in fig. 6, this locking member, generally designated by the general reference numeral 52, takes the form of a lever, the pivot axis and the central symmetry axis of which coincide. More specifically, locking lever 52 has two diametrically opposed arms 53a and 53b by which locking lever 52 abuts both jumper spring 50 and an actuating member 54, which is itself actuated by the date indication correction train. In the example shown in the figure, this actuating member 54 is formed by a wheel 132 of the third multiplier wheel set 13. Of course, this example is given only as an example, it is also possible to envisage locking lever 52 abutting, directly or via an intermediate element, against the other wheels of the date-indicating corrector wheel set.

It can be seen that the arm 53b of the locking lever 52 is held against the teeth of the wheel 132 by the arm 51b of the spring 51, which spring 51 is integral with its arm 51 b. Of course, it is contemplated that two separate springs may be provided for retaining jumper spring 50 and locking bar 52, respectively. It can also be seen that jumper spring 50 includes a recess 56 that facilitates the abutment of arm 53a of locking lever 52.

The operation of the device for helping to maintain the position of the date ring according to the present invention will be studied with reference to fig. 7A to 7F. During normal operation of the watch, i.e. outside the phase in which the date indication is corrected, locking lever 52 is locked between wheel 132 of third multiplier wheel set 13 and jumper spring 50, locking lever 52 keeping jumper spring 50 firmly pressed against top date ring 2. Since multiplier wheel set 13 and top date ring 2 are both stationary, there is no risk of top date ring 2 moving in the event of a shock. Shortly before midnight the watch enters the date indication correction phase and the control wheel 4 starts to rotate (fig. 7A). Since locking lever 52 is held by arm 51b of spring 51 against wheel 132 of third multiplier wheel set 13, there is no clearance between lever 52 and wheel 132. However, there are clearances between wheel 132 and the top gear of corrector wheel set 9 and between the top gear of corrector wheel set 9 and top date ring 2, and these clearances are superimposed on each other. In this way, when control wheel 4 and therefore wheel 132 of third multiplier wheel set 13 start to rotate, said wheel 132 first drives locking lever 52 before driving corrector wheel set 9 and date ring 2. In this way, wheel 132 will move lever 52 away from its locked position against the return force of arm 51B of spring 51 and thereby release jumper spring 50 (fig. 7B). Wheel 132 immediately begins to rotate date ring 2 via the top gear of corrector wheel set 9, immediately after lever 52 has been moved from its position in which it locks jumper spring 50. From this point on (see fig. 7C), jumper spring 50 becomes the control member for locking lever 52. At this stage it can be observed that arm 53a of locking lever 52 has exited from a recess 56 provided on jumper spring 50 and slides against a straight side 58 of said jumper spring 50, this side 58 being in the extension of said recess 56. Thus, when date ring 2, driven by the top gear of corrector wheel set 9, starts to rotate, jumper spring 50 in turn pivots so as to move from the gap between the two teeth 22 of the top toothing of date ring 2, in which it is located, to the next gap, beyond the tooth 22 separating the two gaps. Upon pivoting, jumper spring 50 causes locking lever 52 to pivot in the clockwise direction, i.e. in the same direction as wheel 132 caused it to pivot, against the return force of arm 51b of spring 51, which tends to return lever 52 to the position in which lever 52 locks jumper spring 50.

In fig. 7D, the date mechanism according to the present invention is shown in a position just before the date indication changes from a given date of the month (in this case date "16") towards the next date (here "17"). As can be seen from this figure, jumper spring 50 rests with its heel (heel) against a tooth 22 of the ring gear of date ring 2, said tooth 22 separating the space between two teeth 22 in which jumper spring 50 is located from the next space into which jumper spring 50 will fall. In addition, jumper spring 50 keeps rod 52 out of the equilibrium position where rod 52 locks jumper spring 50.

When going from fig. 7D to fig. 7E, the top gear of corrector wheel set 9 has finished moving top date ring 2 forward, and jumper spring 50 has fallen into the gap between the two rear teeth 22 under the action of the elastic return force of arm 51a of spring 51. During the jump of jumper spring 50, jumper spring 50 becomes the driving element of date ring 2, date ring 2 completes pivoting and is restrained from forward movement by heel 60 of said jumper spring 50, the inclined surface of jumper spring 50 coming into contact with the two rear teeth 22. Simultaneously, locking lever 52 rises up side 58 of jumper spring 50. In fig. 7F, which shows the date mechanism according to the invention after a date jump, the end of arm 53b of locking lever 52 has returned into recess 56 of jumper spring 50, locking it again.

From the above it can be seen that top date ring 2 is stably locked, and therefore has a high level of resistance to shocks and is not susceptible to unwanted jumps. More specifically, during the normal operating phase of the watch, top date ring 2 is held in the locking position by locking lever 52, and during the date indication correction phase, date ring 2 is held by the top gear of corrector wheel set 9.

Discussed above is top date ring 2. The invention can be applied in the same way to the bottom date ring 3. Thus, the locking bar 52' may be arranged below the locking bar 52 and be pivotally mounted about the same axis as the locking bar 52. This locking lever 52 ' cooperates with the wheel 122 of the fourth multiplier gear set 14 and with a jumper spring 50 ', which jumper spring 50 ' is mounted below the jumper spring 50 and pivots about the same axis as the jumper spring 50. Locking lever 52 ' is held against wheel 122 by spring 51b and jumper spring 50 ' is held in position marking bottom date ring 3 by spring 51a '. The two springs 51b 'and 51 a' may be separate from or integral with each other. It is also conceivable to make the four springs 51a, 51a ', 51b and 51 b' as a single member in the form of pairs of parallel elastic pieces, as shown in fig. 6.

Claims (6)

1. A device for assisting in maintaining the position of a date ring (2; 3) for a timepiece, the position of the date ring (2; 3) being indicated by a jumper spring (50; 50 '), the device comprising a locking member (52; 52 ') arranged to keep the jumper spring (50; 50 ') locked outside a date indication correction period, the locking member (52; 52 ') itself being locked between the jumper spring (50; 50 ') and a toothed wheel (132; 122) of a gear train (11, 13, 9; 12, 14, 9) kinematically connecting the control wheel (4) and the date ring (2; 3), the control wheel (4) being arranged to complete one revolution in 31 days, the locking member (52; 52 ') being arranged to be moved away from a position in which it locks the jumper spring (50; 50 ') by the toothed wheel (132; 122) during the date indication correction period, the toothed wheel (132; 122) is itself driven by a gear train (11, 13, 9; 12, 14, 9), the device being characterized in that the locking member (52) is a locking lever comprising two diametrically opposed arms (53a, 53b) via which the locking lever abuts against a jumper spring (50) and the toothed wheel (132), respectively.

2. The device according to claim 1, characterized in that the locking lever (52; 52 ') is held against the toothed wheel (132; 122) by an arm (51 b; 51 b') of a spring (51; 51 ') so that there is no play between the lever (52; 52') and the toothed wheel (132; 122).

3. Device according to claim 2, characterized in that said jumper spring (50; 50 ') is held in a position in which it indicates the date ring (2; 3) by a resilient arm (51 a; 51 a') of a spring (51; 51 '), which is integral with an arm (51 b; 51 b') of the spring (51; 51 ') holding the locking lever (52; 52').

4. Device according to claim 3, characterized in that the spring (51; 51 ') holding the two locking levers (52; 52 ') and the two jumper springs (50; 50 ') is made as a single part.

5. Device according to claim 1, characterized in that, in the normal operating mode of the timepiece, the end of the arm (53b) of the locking lever (52) abuts against the jumper spring (50) within a recess (56) formed in the jumper spring (50).

6. The device according to claim 5, characterized in that during the date indication correction, the locking lever (52) is driven in rotation by a toothed wheel (132) against the return force of a spring (51) and is moved away from the position in which it locks the jumper spring (50) so as to slide, via its arm (53a), along a straight side (58) of the jumper spring (50) which is in the extension of a recess (56), so that the jumper spring (50) forced to pivot by the date ring (2) becomes the control member of the locking lever (52).