EP1411400B1 - Fixation device for a coaxial wheel in a timepiece, in particular of a date display disc - Google Patents

Description

The present invention generally relates to the assembly of coaxial mobiles, in particular the mounting of indicator discs (eg day indicator discs, calendars, months or the like), in timepieces. The present invention relates more particularly to the mounting of such coaxial mobiles by their center on a central support member, and in particular the mounting of a coaxial mobile on a mobile timer of a timepiece.

Coaxial mobiles such as indicator discs mounted by their center are commonly retained axially by an additional element, namely a circlip engaged in a groove formed on the periphery of the central support member on which the disc is mounted (typically a shaft, an axis or the barrel of a timer mobile). This circlip is commonly in the form of an open or closed ring having elastic characteristics for insertion into the groove of the central support member.

The document US 3,659,412 shows for example the fixing of an indicator disc on the barrel of a mobile timer (in this case an hour wheel) and its axial retention by means of different examples of circlips open or closed. Note that the indicator disc is typically integral with a star collaborating with a suitable drive system and that the angular position of the indicator disc is indexed by means of a jumper spring being housed between two teeth of the star.

It will thus be noted that the axial retention of the indicator disc on its central support member is achieved by means of an additional element which increases the manufacturing costs of the timepiece and involves an additional assembly step consisting of the introduction circlip in the corresponding groove of the central support member.

An object of the present invention is to provide a solution to overcome the use of an additional retaining element and consequently to reduce manufacturing costs and limit the number of assembly steps of the workpiece. watchmaking.

The present invention thus has as its first object a device for fixing a coaxial mobile for a timepiece whose characteristics are set forth in independent claim 1, as well as in independent claim 19.

The present invention also relates to a timer mobile for receiving a coaxial mobile whose characteristics are set forth in independent claim 11.

Advantageous embodiments of the present invention are the subject of the dependent claims.

According to the invention, the coaxial mobile is thus retained axially on its support member via a plurality of resilient fingers. In this way, it eliminates the need to provide an additional axial retention element to maintain the coaxial mobile on the support member. These resilient fingers preferably form an integral part of the support member. As an alternative, these resilient fingers may be provided on the coaxial mobile itself.

The assembly of the coaxial mobile on its support member is also very simple in that it is sufficient to introduce the mobile on the support member parallel to its axis, the plurality of elastic fingers deforming radially to the passage of the mobile to return then in place is to ensure the axial retention.

• la figure 1 est une vue en coupe partielle, selon une ligne de coupe A-A, d'un mouvement d'une pièce d'horlogerie montrant un exemple de réalisation préféré d'un dispositif de fixation d'un disque indicateur des jours sur le canon d'une roue des heures ;
• la figure 2 est une vue en plan partielle, côté cadran, du dispositif de fixation illustré dans la figure 1 ;
• la figure 3a est une vue en coupe partielle, analogue à la vue en coupe de la figure 1, illustrant de manière détaillée le dispositif de fixation lors du montage du disque indicateur des jours sur le canon de la roue des heures ;
• la figure 3b est analogue à la figure 3a et illustre le dispositif de fixation après montage du disque indicateur des jours sur le canon de la roue des heures ; et
• les figures 4a et 4b sont deux vues isométriques, respectivement des parties supérieure et inférieure de la roue des heures à canon du mouvement des figures 1 à 3b.

Other characteristics and advantages of the present invention will emerge more clearly on reading the following detailed description of a preferred embodiment of the invention given solely by way of nonlimiting example and illustrated by the appended drawings in which:

• the figure 1 is a partial sectional view, along a line of section AA, of a movement of a timepiece showing a preferred embodiment of a device for fixing a disc indicating the days on the barrel of a hour wheel;
• the figure 2 is a partial plan view, on the dial side, of the fastener shown in FIG. figure 1 ;
• the figure 3a is a partial sectional view similar to the sectional view of the figure 1 , illustrating in detail the fixing device during assembly of the day indicator disc on the barrel of the hour wheel;
• the figure 3b is analogous to the figure 3a and illustrates the fixing device after mounting the indicator disk of the days on the barrel of the hour wheel; and
• the Figures 4a and 4b are two isometric views, respectively of the upper and lower parts of the clock wheel of the movement of the Figures 1 to 3b .

The figures show a preferred embodiment of a coaxial mobile attachment device according to the present invention. In this case, the fixing device illustrated is intended to ensure the fixing and retention of a day indicator disc, designated generally by the reference numeral 2, on the barrel 11 of a wheel hours 1 of a watch movement.

The timepiece movement of the type with second in the center is visible in part on the section of the figure 1 and the plan view of the figure 2 (Note that the cuts are made according to the cut line AA reported on the figure 2 ). It distinguishes including a bridge gear 8 and a plate 9 defining a cage in which is the essence of the movement. There is in particular a second mobile 3 in the center, pivotally mounted on the gear train 8, with its second axis 30, second gear 31 and its second wheel 32, a roadway 4 disposed directly on the axis 30 of the second mobile 3 and a drive wheel 42 frictionally mounted on the roadway 4. This drive wheel 42 is typically engaged with a pinion of average (not shown) integral with a medium wheel (not shown ) which meshes with the second pinion 31. The roadway 4 typically transmits its rotational movement to a timer wheel (not shown) which meshes in its end part, on the dial side, with the hour wheel 1 via its timer pinion (not shown) The outer face of the plate 9 further comprises an annular shoulder 91 serving as a radial positioning guide to the hour wheel 1, itself provided in its base with a corresponding recess for accommodating this shoulder 91. Finally, note that the hour wheel 1, freely mounted rotationally on the roadway 4, also incorporates a reference 12 of a drive wheel 5 actuating an inner toothed date disc 6 and the indicator disc of the days 2.

The indicator disc of the days 2 comprises meanwhile a star 21 days integral with a disc 22 bearing the inscriptions of the days of the week, which are typically intended to appear successively in a window of the dial (not shown). For the sake of clarity, the disk 22 is not shown in the plan view of the figure 2 , only the star of days 21 being represented. The indicator disk of the days 2 is typically operated every day (once every 24 hours), around midnight, through the drive wheel 5 by means of a finger 51 which is secured thereto. This drive wheel 5 is of a specific type of which a further description can be found in the document EP 0 548 659 , also in the name of this Depositor.

The position of the indicator disc of the days 2 can further be corrected by means of a correction mechanism (typically driven by a stem-crown). A correction wheel 25 forming part of this correction mechanism is illustrated in the figures 1 and 2 . It will also be noted that the angular position of the indicator disk of the days 2 is indexed by means of a jumper spring 72, a part of which appears on the section of the figure 1 . This spring jumper 72 is part of a plate of 7 which is secured to the plate 9 and which also incorporates, as illustrated in the figure 2 , a jumper spring 76 for indexing the date disc 6.

We will now focus more particularly on the structure of the wheel hours 1 and its barrel 11 which are strictly speaking the central support member of the indicator disk days 2 to ensure the fixing and the axial retention. The figures 3a and 3b show enlarged views of the cup of the figure 1 , respectively during assembly and after mounting the indicator disc 2 on the barrel 11 of the hours wheel 1. The Figures 4a and 4b show in turn isometric views of the hour wheel 1 and its barrel 11. According to the invention, the barrel 11 of the hour wheel 1 thus carries a plurality, here three, of elastic fingers 15 extending radially towards the outside of the barrel 11 and intended to ensure axial retention of the indicator disc 2 on the barrel 11. These elastic fingers 15 are preferably arranged symmetrically around the barrel 11 (in this example 120 ° from each other).

In the illustrated configuration, the elastic fingers 15 are arranged to deform elastically towards the inside of the barrel 11 to allow axial insertion of the indicator disc 2, through its central mounting hole 2a, on the barrel 11 of the wheel of the hours 1. The figures 3a and 3b to highlight what has just been mentioned. Indeed, as illustrated in the figure 3a when the indicator disk 2 is inserted, the star of the days 21 comes into contact with the end of the fingers 15 so that they are forced to deform radially toward the axis of the hour wheel 1. Once the disc 2 has been inserted, as shown in figure 3b , the fingers 15 return to their rest position to axially retain the disc 2 by its star of days 21. In this position, it will be understood that the indicator disc 2 is free to rotate around the barrel 11.

It will be further understood that when mounting the indicator disc 2 on the hour wheel, it will be necessary to ensure that the star of the days 21 meshes well with its drive wheel 5, its correction wheel 25 and with the end of jumper spring 72.

As illustrated in the figures, the configuration of the barrel 11 of the hour wheel 1, according to the preferred embodiment, is such that this barrel 11 has an end portion 11a intended for the introduction of an hour hand (no shown), a first middle portion 11b where the elastic fingers 15 are arranged, a second middle portion 11c of substantially similar (but smaller) diameter to the diameter of the mounting hole 2a of the indicator disc of days 2 and around which rests radially this indicator disc, and a range 11d on which axially rests the indicator disc of days 2 (this range 11 d is here formed by the face of the reference 12 of the date wheel).

In this preferred embodiment, it will be noted that the second middle portion 11c accommodating the indicator disc of the days 2 comprises a plurality of radial recesses 16, in number equivalent to the number of elastic fingers, formed in positions corresponding angularly to the positions of the fingers. In this way, once assembled, the disc of the days 2 rests directly on the second middle portion 11c, rigid, the elastic fingers 15 returning to their rest position once the indicator disc 2 inserted to ensure its restraint axial. It should of course be noted that the elastic fingers 15 extend radially from the barrel 11 over a distance slightly greater than the corresponding radius of the mounting orifice 2a of the indicator disc 2 so as to ensure, in the rest position, the axial retention of the disc 2. These elastic fingers 15 must also be flexible enough to deform during insertion of the disc and allow the passage of the latter.

Note that the radial recesses 16 extend as illustrated towards the base of the hour wheel 1. In fact, the hour wheel, or generally the central support member of the indicator disc, is preferably made of a synthetic material like a plastic. The illustrated configuration of the radial recesses 16 makes it possible, for this reason, to simplify the construction of the mold of the hour wheel 1. However, it should be noted that the use of a plastic material is not obligatory, any material having sufficient elastic characteristics for the desired goal can be used.

Note also that the first middle portion 11b of the barrel 11 of the hour wheel 1 furthermore preferably comprises a plurality of radial guides 17 (also three in number in this example) arranged between the elastic fingers 15 to guide the indicator disk. 2 during its insertion on the hour wheel 1. These guides 17 make it possible to ensure good radial positioning of the indicator disk 2 during its insertion and also protect the elastic fingers 15 of the hour wheel so that they do not undergo that minimal deformation during the insertion of the indicator disc 2. Preferably, these radial guides 17 are arranged so that they are the first to come into contact with the indicator disc 2 during its insertion. More exactly, the radial guides 17 and the elastic fingers 15 have, in their upper part, a chamfer whose angle differs. In this case, the angle of the chamfer practiced on the radial guides 17 is less important (with respect to a perpendicular to the axis of insertion of the indicator disc) than the angle of the chamfer practiced on the flexible fingers. In this way, the disc indicator is first guided and centered on the axis by the guides 17 (cf. figure 3a ) before actually making contact with the elastic fingers 15. Other configurations can obviously be envisaged. The guides 17 can thus simply be placed higher in the barrel 11 of the hour wheel 1.

It will be understood in general that various modifications and / or improvements obvious to those skilled in the art can be made to the embodiment described in the present description without departing from the scope of the invention defined by the appended claims. In particular, the present invention is not limited solely to the fixing of a disc of the days and its star on the barrel of an hour wheel, but applies in a similar manner to allow the attachment of any other mobile coaxial to be mounted on a central support member such as a timer or any other support element, whether it is fixed or mobile. The solution described remains however particularly advantageous for the application presented above.

Note also that the invention is not limited to the fixing of a disc indicator days, but can be applied to any other type of indicator disc mounted by its center on a central support member, such for example a record of dates, months, or even moon phases.

As an alternative to the embodiment presented above, it will be noted that it is conceivable to spare the elastic fingers, not on the central support member, but on the coaxial mobile itself. In this case, the plurality of elastic fingers would extend radially inwardly of the coaxial mobile (that is to say in the direction of the axis of rotation of the assembly), these elastic fingers being similarly arranged to elastically deform to allow axial insertion of the coaxial mobile on the central support member and to return to a rest position to ensure axial retention of the coaxial mobile.

Claims (19)

1. Device for securing a wheel set for a timepiece, including a central support member (1, 11) and a coaxial wheel set (2) mounted to rotate freely on said central support member (1,11),
   characterized in that said central support member (1, 11) carries a plurality of elastic fingers (15) that extend radially towards the exterior of said central support member (1, 11), each of said elastic fingers (15) being arranged to deform elastically, enabling said coaxial wheel set (2) to be axially inserted on said central support member (1, 11) and to return to an idle position so as to ensure axial retention of said coaxial wheel set (2).
2. Securing device according to claim 1, characterized in that in said axial insertion direction of the coaxial wheel set, said central support member (1, 11) has an end part (11 a), a first median part (11 b) where said elastic fingers are arranged, a second median part (11c) around which said coaxial wheel set (2) rests radially, and a shoulder (11d) on which said coaxial wheel set (2) rests axially.
3. Securing device according to claim 2, characterized in that said second median part (11c) of the central support member (1, 11) has a plurality of radial recesses (16), in an equivalent number to the number of elastic fingers (15), arranged in radial positions that conform to the positions of said elastic fingers (15).
4. Securing device according to claim 2, characterized in that said first median part (11b) of the central support member (1, 11) also has a plurality of radial guides (17) arranged between said elastic fingers (15) for guiding said coaxial wheel set when said wheel set is inserted onto the central support member (1, 11).
5. Securing device according to claim 4, characterized in that the chamfer angle on said radial guides (17) is smaller than the chamfer angle on said elastic fingers (15) so that the radial guides (17) are the first to enter into contact with the coaxial wheel set (2) when said wheel set is inserted.
6. Securing device according to claim 4, characterized in that the radial guides (17) are placed higher than said elastic fingers (15) so that the radial guides (17) are the first to enter into contact with the coaxial wheel set (2) when said wheel set is inserted.
7. Securing device according to any of the preceding claims, characterized in that said elastic fingers (15) are arranged symmetrically around the axis of said central support member (1, 11).
8. Securing device according to any of the preceding claims, characterized in that said central support member (1, 11) is a motion wheel set of the timepiece, such as an hour wheel.
9. Securing device according to any of the preceding claims, characterized in that said coaxial wheel set (2) is a disc indicating the days of the week or month, the months, or the phases of the moon.
10. Securing device according to any of the preceding claims, characterized in that said central support member (1, 11) is made of a synthetic material, such as plastic.
11. Motion wheel set (1), particularly an hour wheel, for a timepiece for mounting a coaxial wheel set (2), such as an indicator disc, which rotates freely relative to said motion wheel set (1), wherein said motion wheel set includes a pipe (11), characterized in that said pipe carries a plurality of elastic fingers (15) which extend radially towards the exterior of said pipe (11) and which are arranged to deform elastically when said coaxial wheel set (2) is inserted onto the pipe (11) and to return to an idle position to ensure axial retention of said coaxial wheel set (2).
12. Motion wheel set according to claim 11, characterized in that in said axial insertion direction of the coaxial wheel set (2), said pipe (11) has an end part (11 a) for receiving a hand, a first median part (11 b) where said elastic fingers (15) are arranged, a second median part (11c) for supporting said coaxial wheel set (2) radially, and a shoulder (11d) for supporting said coaxial wheel set (2) axially.
13. Motion wheel set according to claim 12, characterized in that said second median part (11c) of the pipe (11) has a plurality of radial recesses (16), in an equivalent number to the number of elastic fingers (15), arranged in positions that conform radially to the positions of said elastic fingers (15).
14. Motion wheel set according to claim 12, characterized in that said first end part (11b) of the pipe (11) further includes a plurality of radial guides (17) arranged between said elastic fingers (15) for guiding said coaxial wheel set (2) when said wheel set is inserted onto the pipe.
15. Securing device according to claim 14, characterized in that the chamfer angle on said radial guides (17) is smaller than the chamfer angle on said elastic fingers (15) so that the radial guides (17) are the first to enter into contact with the coaxial wheel set (2) when said wheel set is inserted.
16. Securing device according to claim 14, characterized in that the radial guides (17) are placed higher than said elastic fingers (15) so that the radial guides (17) are the first to come into contact with the coaxial wheel set (2) when said wheel set is inserted.
17. Motion wheel set according to any of claims 11 to 16, characterized in that the elastic fingers (15) are arranged symmetrically around the axis of said pipe (11).
18. Motion wheel set according to any of claims 11 to 17, characterized in that said pipe (11) of the motion wheel set (1) is made of a synthetic material, such as plastic.
19. Securing device for a timepiece wheel set including a central support member (1, 11) and a coaxial wheel set (2) mounted to rotate freely on said central support member (1, 11),
    characterized in that said coaxial wheel set (2) carries a plurality of elastic fingers that extend radially towards the interior of said coaxial wheel set (2), each of said elastic fingers being arranged to deform elastically, enabling said coaxial wheel set (2) to be axially inserted onto said central support member (1, 11), and to return to an idle position to ensure axial retention of said coaxial wheel set (2).

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