EP1536300A1 - Calendar mechanism for a watch comprising two superposed date annuli - Google Patents

Abstract

The mechanism has two superposed respectively lower (6) and upper (4) date rings. A surface of the rings is divided into a set of sectors. The upper ring has sixteen sectors, and the lower ring has seventeen sectors. Each ring cooperates with a drive unit so that markings appear in a display zone (20). A jumper-effect stopping device (22) has two jumpers (24,26) to stop each ring in any desired position.

Description

The present invention relates to a date mechanism with a large date comprising two superposed date rings, respectively upper and lower, one of which carries fifteen successive markings of a cycle of 31 positions, while the other carries the other sixteen markings.

Counter metering and cyclic display devices used in calendar timepieces for displaying the date are already known. Usually, the analog display of the date is conventionally made using a date ring which comprises 31 sectors bearing the markings from 1 to 31. However, such a device has the disadvantage of not offering, for each sector, a field whose size corresponds to a 31 ^th of the circumference of the ring. Especially in small format wristwatches, the dimensions of this field are insufficient to allow an easily readable date display. The need for a device to display a "large date" on a field much wider than a 31 ^th circumference has been felt.

A first solution to this problem was provided by the Swiss patent application CH 660 941 in the name of Brandi, the purpose of which is to provide a counting device and cyclic display with a window for a watch date which, while being purely mechanical and a simple configuration, allows to give the date indication a large format, at least approximately double that of a 31 ^th of circumference.

For this purpose, the Brandi patent teaches a date mechanism comprising mainly a date ring greater than sixteen sectors, superimposed on a lower ring with seventeen sectors. The upper ring bears on fifteen of its sectors markings "17" to "31" while the last sector is equipped of a window. The lower ring has on sixteen of its sectors the markings "1" to "16", while the last sector is free of marking. The circumference inside of the two rings has teeth, a place for the upper ring and a place for the lower ring being toothless. A training finger of date, classically making a turn every twenty-four hours, coaching the calendar rings in a classical way, by action on their teeth. The driving position of the finger relative to the teeth of the rings is such that, when a ring has its free position (aperture for the upper ring and sector free of marking for the lower ring), at the display location of the shows, the finger drive is in front of the tooth-free position of the ring concerned.

The Brandi patent provides a date mechanism for a timepiece which advantageously makes it possible to give the date indication a large format, substantially double that of a conventional date mechanism. It arises nevertheless a problem in the positioning of the date rings. In effect, in accordance with the Brandi patent, two jumper devices act respectively on the teeth of the upper ring and on the teeth of the lower ring. But, considering the fact that a place of the teeth of each of these rings is toothless, these chokers must be double-pointed and press on the tips of three successive teeth. These jumpers must therefore be large dimensions and are therefore bulky. On the other hand, the characteristics mechanical restraint of the restraint exerted by the jumpers on the two rings of date are different depending on whether the missing tooth is in first, second or third position vis-à-vis said jumpers. So we have to find a compromise that ensure that whatever the position of the missing tooth, the jumper ensures satisfactory positioning of the ring concerned. Such jumpers are difficult to develop.

The present invention aims to overcome the disadvantages mentioned above and others by providing a date mechanism to give the date indication a large format, this mechanism comprising two superposed rings, respectively upper and lower, whose one carries fifteen successive markings of a cycle of 31 positions, while the other wears the other sixteen markings, a jumper device allowing to properly position the two rings.

For this purpose, the present invention relates to a date mechanism for timepiece such as a wristwatch comprising two rings of superposed date, respectively lower and upper, the surface of which divides into a plurality of sectors, the upper ring comprising sixteen sectors, fifteen of which respectively bear fifteen successive markings of a cycle of 31 positions and of which the sixteenth is a surplus sector with a window open or transparent, while the lower ring comprises seventeen sectors, of which sixteen respectively carry the other sixteen markings in the cycle of 31 positions and of which the seventeenth is a surplus sector, each of these rings being equipped with a peripheral toothing made of a succession of teeth regularly spaced apart and cooperating with training means in such a way that the markings of the lower ring appear successively in an area display through the window, the upper ring remaining stationary, then that, the lower ring being immobile, the markings of the upper ring appear successively in the display area, the upper ring covering the markings of the lower ring, the date mechanism further comprising a jumper device capable of stopping each ring in all desired position, the stopping device being adapted to the pitch of the particular ring concerned, said date mechanism being characterized in that a location of the upper ring and a place in the lower ring is provided with a thinned tooth located between two successive teeth of the teeth of the ring concerned, the position means of training with respect to the teeth of the rings being such that when a ring has its surplus sector at the location of the display area, the thinned tooth is located vis-à-vis the drive means so that said means of training drive only the other ring, the teeth thinned two rings do not interfere with the movement of the drive means and allowing stopping device to be constantly housed between two successive teeth of each of the rings.

Thanks to these features, the present invention provides a mechanism for timepiece calendar comprising an arresting device jumper simple to manufacture and allowing an adequate positioning of the two rings of date. Indeed, unlike the prior art where, because of the fact that place of the toothing of each of the calendar rings was toothless, the jumpers had to be double top and press between the points of three teeth successive, the jumpers according to the invention are constantly housed between two teeth successive teeth of each of the rings even during the passage of the tooth thinned. The jumpers according to the invention thus end classically by two inclined planes that support between the tips of two teeth immediately successive steps to keep the relevant date ring in the desired position. These jumpers are therefore of classic design and exert on the rings of date a holding force of constant intensity, whatever the position said rings.

• la figure 1 est une vue de dessus d'une boíte de montre comprenant un mécanisme de quantième conforme à l'invention;
• la figure 2 est une vue en perspective de l'anneau de quantième supérieur;
• la figure 3 est une vue en perspective de l'anneau de quantième inférieur;
• la figure 4 est une vue analogue à celle des figures 2 et 3, les anneaux de quantième inférieur et supérieur étant superposés;
• la figure 5 est une vue éclatée du mécanisme de quantième, et
• la figure 6 est une représentation schématique des dentures périphériques des anneaux de quantième inférieur et supérieur.

Other features and advantages of the present invention will emerge more clearly from the detailed description which follows of an embodiment of the date mechanism according to the invention, this example being given purely by way of illustration and not only in connection with the appended drawing in which:

• Figure 1 is a top view of a watch case comprising a date mechanism according to the invention;
• Figure 2 is a perspective view of the upper date ring;
• Figure 3 is a perspective view of the lower date ring;
• Figure 4 is a view similar to that of Figures 2 and 3, the lower and upper date rings being superimposed;
• FIG. 5 is an exploded view of the date mechanism, and
• Figure 6 is a schematic representation of the peripheral teeth of the lower and upper date rings.

The present invention proceeds from the general inventive idea of provide a date mechanism for a timepiece whose device jumping device includes two space saving jumpers, simple to to manufacture and guarantee an adequate positioning of the date discs. This result is achieved because, unlike the prior art where, because of the that a place in the toothing of each of the date rings is devoid of tooth, the jumpers must cooperate with three successive teeth of the teeth of each of the rings to ensure the positioning of these rings, even during the passage of the missing tooth, according to the invention the missing tooth is replaced by a thinned tooth. This thinned tooth plays the same role as the missing tooth, know how to define an extended rest position for the relevant date ring when it presents its free position at the display location of the watch, but ensures that the jumper will be constantly housed between two teeth immediately consecutive teeth of said ring. These jumpers are therefore classic type and exercise on the calendar rings a restraining force constant, even when passing the thinned tooth.

FIG. 1 is a view from above of a watch movement comprising a date mechanism according to the invention. Designated as a whole by the general numerical reference 1, the movement is mounted in a circle 2. The date mechanism according to the invention comprises mainly an upper date ring 4 superimposed on a ring of lower date 6. The upper date ring 4 has sixteen sectors, while the lower date ring 6 has seventeen sectors. As we can see in Figure 1 and even better in Figure 2 and Figure 3, the upper ring 4 covers fifteen of its sectors markings "17" to "31" while the last sector is provided with an open or transparent window 8. The lower ring 6 has meanwhile on sixteen of its sectors the markings "1" at "16" while the last sector is free of marking.

The inner circumference of the rings 4 and 6 has formed toothing a succession of regularly spaced teeth designated by 10 for the ring upper 4 and by 12 for the lower ring 6. A place of the teeth of the rings upper 4 and lower 6 is provided with a thinned tooth designated respectively by 14 and 16. The term "thinned tooth" means a tooth whose height, considered according to the direction perpendicular to the plane in which the date rings 4 extend and 6, is smaller than those of the teeth that precede and follow it.

A training wheel of date 18, classically making a lap every twenty-four hours, causes the rings of date 4 and 6 in a way conventional, by action on the teeth 10 or 12. The position of the drive wheel 18 relative to the teeth of the rings 4 and 6 is such that when one of these rings presents its free position (window 8 for the upper ring 4 and sector free of marking for the lower ring 6) at the display location 20 of the movement of shows 1 (aperture of the dial supposedly removed and which occupies the position where we see the number "16"), the drive wheel 18 is in front of the thinned tooth 14 or 16 of the ring concerned.

A jumper device 22 comprising two jumpers 24 and 26 acts on the teeth 10 of the upper ring 4 and on the teeth 12 of the ring 6. Unlike the prior art where, because of the fact that a place in the tooth of each of the calendar rings is toothless, the chokers must cooperate with three successive teeth of the teeth of each of the rings to ensure the positioning of these rings even when passing the tooth missing, the present invention proposes to replace the missing tooth with a tooth thinned, that is to say less high than the other teeth arranged along the inner periphery of the upper and lower 4 date rings. will see in detail below, the thinned tooth according to the invention plays the same role as the missing tooth according to the prior art, namely to define an extended rest position for the date ring concerned when it presents its free position to the display area 20 of the watch, but makes it possible to guarantee, by its presence, that the jumper will be constantly housed between two immediately consecutive teeth of the toothing of said ring.

At their outer circumference, the date rings 4 and 6 present each a stop, respectively 28 and 30. Figures 2 and 3 show the detail of this arrangement. The stop 28 extends perpendicular to the plane of the ring of upper date 4, while the stop 30 extends radially out of the perimeter outside the lower date ring 6.

In the situation shown in FIG. 4, the upper date ring 4 presents its window 8 at the display location 20, and simultaneously its thinned tooth 14 vis-à-vis the drive wheel 18. It will be understood that the height of the tooth thinned 14 is such that the wheel 18 can not mesh with this tooth and drives only the lower date ring 6 which, to reach the represented position, will have been conducted successively by the drive wheel 18 in situations where he exhibited markings "11", "12", ..., "15" and finally "16". At the moment when the marking "16" appears, the stop 30 comes to bear against the stop 28. At that time, when the advance will be imparted to the lower ring 6 by the wheel 18, the upper ring 4 will also be driven, so that the window 8 will disappear from the display area 20, to make room for the marking "17" of the upper ring "4". At this moment, it will be the lower ring 6 which will present its thinned tooth 16 in front of the drive wheel 18. As for the ring upper 4, the height of the thinned tooth 16 is such that the drive wheel 18 can not meshing with this tooth 16 and drives only the date ring 4. Thus, at each turn of the drive wheel 18, only the ring 4 will advance one step, showing successively the markings "17", "18", ..., "30" and "31". When displaying the marking "31", the situation between two stops 28 and 30 will be the opposite of that described above, that is to say that the stop 28 of the upper date ring 4, abutting against the stop 30 of the lower date ring 6, will cause simultaneously, during the advance of the upper ring 4, the advance of the lower ring 6, which will cause the appearance marking "1" under the window 8, at the display location 20. All the time where the upper ring 4 moved while the lower ring 6 was at rest extended, it is the mark-free area of this one that was in the of display 20, this having no effect since, in this case, the window 8 has no effect. never been at the display location and therefore never let see the lower ring 6. Then, the sixteen markings of the lower ring 6 scroll successively until return to the situation shown in Figure 4. The cycle is repeated then.

FIG. 5 is an exploded view of the movement 1 provided with the mechanism date according to the invention. This movement 1 comprises a plate 32 which supports and guides in rotation the two lower date rings 6 and higher. center of platinum 32 stands classically the axis of the hour wheel 34 on which is engaged the hour wheel 36. A bridge 38 carries the locking device 22 equipped with its two jumpers 24 and 26 which act respectively on the ring of upper date 4 and the lower date ring 6. The wheel 18 includes a wheel 40 driven, via a mobile gear reducer not shown, by the hour wheel 34 so as to perform a complete turn in twenty-four hours. Two fingers 42 and 44 are fixed, for example by welding, on the wheel 40. These two fingers 42 and 44 drive the date rings, respectively upper 4 and lower 6, by action on teeth 10 or 12 of these rings. If the thinned tooth 14 of the upper date ring 4 is located opposite of the drive wheel 18, it will have no effect on said upper ring 4 and will train only by its finger 44 the lower date ring 6 of a step every day. Conversely, if the thinned tooth 16 of the lower date ring 6 is next to the drive wheel 18, the finger 44 can not come into engagement with this tooth 16 of said lower ring 6, and only the upper ring 4 will advance one step each day.

The drive wheel 18 is mounted freely on an axis 46 of the bridge 38. Finally, the date mechanism according to the invention is held axially on the plate 32 by means of a holding plate 48 fixed with screws 50.

FIG. 6 is a developed representation of the teeth of the rings of upper 4 and lower 6. As can be seen from the examination of this figure, the upper date ring 4 has sixteen teeth identified by the numbers 1,2, ...., 15 and 16, while the lower date ring 6 comprises seventeen teeth identified by the numbers 1, 2, ..., 16 and 17. The upper ring 4 comprises therefore 16 divisions, while the lower ring 6 has 17 divisions. Teeth 10 and 12 rings respectively upper 4 and lower 6 are therefore shifted one against the other. The positions of the thinned teeth 14 and 16 of the rings upper 4 and lower 6 are marked with circles in solid lines. The position of the drive wheel 18 vis-à-vis the teeth of the upper 4 and lower rings 6 is marked by the line segment A-A. Finally, the two jumpers 24 and 26 are materialized by two rectangles bearing the same numerical references. As can be seen from the drawing, the height of the two jumpers 24 and 26 is equal to the thickness of the teeth 10 and 12.

In the situation shown in FIG. 6, the upper date ring 4 has its thinned tooth 14 next to the drive wheel 18. This position corresponds to the situation in which the upper ring 4 has its window 8 to the display place 20 of the movement and reveals the number "16" carried by the ring lower (see also Figure 4). At the moment when the marking "16" appears, the stop 30 of the lower date ring 6 abuts against the stop 28 of the upper ring 4. Thus, during the advance which will be imparted to the lower ring 6 by the drive wheel 18, the upper ring 4 will also be driven. It will be then the lower ring 6 which will present its thinned tooth 16 next to the wheel 18, while the thinned tooth 14 of the upper ring 4 will have advanced one step.

As already mentioned above, the height of the two jumpers 24 and 26 is substantially equal to the thickness of the teeth 10 and 12, so that even during passage of the thinned tooth, respectively 14 or 16, said jumpers always remain engaged between two teeth immediately consecutive teeth of the disks upper and lower, ensuring proper positioning of these discs.

It goes without saying that the present invention is not limited to the embodiment which has just been described, and that various modifications and simple variants can be contemplated by those skilled in the art without departing from the scope of the present invention. In In particular, the upper date ring could have seventeen sectors, while the lower ring would count only sixteen.

Claims (3)

Timepiece mechanism for a timepiece such as a wristwatch comprising two superposed, respectively lower (6) and upper (4) superposed date rings, the surface of which is divided into a plurality of sectors, the upper ring (4) ) comprising sixteen sectors, fifteen of which respectively carry fifteen successive markings of a cycle of 31 positions, and the sixteenth of which is a surplus sector having an open or transparent window (8), whereas the lower ring (6) comprises ten seven sectors, of which sixteen carry respectively the other sixteen markings of the cycle of 31 positions, and the seventeenth of which is a surplus sector, each of these rings (4, 6) being provided with a peripheral toothing made of a succession of teeth, respectively (10) and (12), regularly spaced and cooperating with drive means so that the markings of the lower ring (6) appear successively in a zone of display (20) through the window (8), the upper ring (4) remaining stationary, and that, the lower ring (6) being immobile, the markings of the upper ring (4) appear successively in the display area (20), the upper ring (4) covering the markings of the lower ring (6), the date mechanism further comprising a stop device (22) by jumper effect able to stop each ring (4, 6) in any desired position, the stop device being adapted to the pitch of the particular ring (4, 6) concerned, said date mechanism being characterized in that a location of the upper ring ( 4) and a location of the lower ring (6) is provided with a tapered tooth, respectively (14) and (16), located between two successive teeth (10) or (12) of the toothing of the ring ( 4) or (6), the position of the drive means relative to the teeth of the rings (4, 6) being such that when a ring (4) or (6) pr extends its surplus sector at the location of the display area (20), the thinned tooth (14) or (16) is opposite the drive means so that said drive means only drive the other ring, the thinned teeth (14, 16) not impeding the movement of the drive means and allowing the stop device (22) to be constantly housed between two successive teeth (10) or (12) of each of the rings (4, 6). Date mechanism according to claim 1, characterized in that the stop device (22) comprises two jumpers (24) and (26) whose height is substantially equal to the thickness of the teeth (10, 12). Date mechanism according to any one of claims 1 or 2, characterized in that the drive means comprises a wheel (18) which rotates in 24 hours and which is provided with two fingers (42) and (44) which respectively cause the calendar rings (4) and (6) by action on their teeth (10, 12).

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