EP1278108B1 - Device for adjusting the alignment of a back cover, which is screwed on the middle of a watchcase, with respect to an axis 12H-6H - Google Patents

Abstract

The intermediate assembly (1) which is a pressed fit within the watchcase consists of an elastic blocking ring (4) which contains a metallic threaded ring (2). The watchcase base (6) is screwed into the metallic ring using a threaded rim (8,10). If the alignment of any base markings is not satisfactory it may be rotated with complementary motion of first the metallic ring and then the blocking ring after engagement of lug (20). A case lug (67) facilitates unscrewing

Description

The present invention relates to a system for adjusting the alignment of a bottom screwing on the middle of a watch case with respect to a vertical axis 12 hours-6 hours.

It often happens that, when the face of a watchcase back on the middle of the case, it is found that when the bottom is completely screwed, the inscriptions or decorative patterns that may have been stamped for example or engraved on the face of the bottom located on the wrist side of the wearer of the watch, are not properly aligned with respect to the vertical axis 12 o'clock-6 o'clock of said watch, which, of course, damages the appearance aesthetic of this watch.

This lack of appearance, if it can be tolerated for cheap watches, is a disadvantage very troublesome for more expensive watches.

To remedy this drawback, the only known solution to date is to match a bottom with a watch case determined during machining, so that one is assured that once completely screwed, the bottom is perfectly aligned with the axis 12h-6h of the watch. This solution, however, is unsatisfactory because we are exposed to problems if the original background of the watch is lost or damaged and it is necessary to replace it with another background which is not sure that once screwed on the middle part, it always aligns appropriately with the vertical axis 12h-6h.

The present invention aims to overcome this disadvantage as well as others by proposing a system allowing, after screwing a bottom on the middle of a watch case, to simply and efficiently adjust the alignment of this bottom with respect to the axis 12h-6h of the watch, so as to ensure a suitable arrangement of the inscriptions and other decorative motifs that have been reported on the face of the watch bottom directed towards the wrist of the wearer of the this watch.

For this purpose, the present invention relates to a device for fixing a bottom to a middle part of a watch case, as defined by claim 1.

The document CH 333 257 discloses the preamble of claim 1.

The present invention provides a device for fixing a watchcase bottom which allows both to screw the bottom completely on the middle part of the watch so as to seal the latter and to avoid as much risk as possible to lose said bottom, then, although the bottom is screwed to block, to pivot this bottom relative to the middle part to catch any misalignment of the inscriptions or patterns applied to the visible face of said bottom relative to the axis 12h-6h of the watch.

The problems of the prior art are thus solved. In particular, we are no longer obliged to machine the backs and squares in pairs with great precision to be assured that the assembly, when a bottom is completely screwed on the middle that corresponds to it, ' background will be properly aligned with the vertical axis of the watch. By reducing the requirements related to the precision with which the backs and sides have to be machined, the present invention therefore makes it possible to significantly reduce manufacturing costs and to limit the number of parts that must be discarded because of machining defects. which has, of course, a favorable impact on the cost price of the finished watch.

According to another characteristic of the invention, the intermediate element comprises a resilient locking element and a metal element which is concentrically disposed inside the elastic locking element, the bottom being screwed onto the metal element. so that when the bottom is completely screwed onto said metal element, this metal element can be forced to pivot relative to the middle part of the watch by sliding on the elastic locking element which remains fixed to a stop point from which the metallic element becomes fixed again with respect to the elastic locking element which, in turn, can be forced to pivot by sliding on the middle part of the watch by being pivotally driven by said metal element, this making it possible to adjust the alignment of the bottom with respect to the vertical axis 12h-6h of said watch.

According to yet another characteristic of the invention, the adjustment torque of the alignment of the bottom relative to the vertical axis is less than the locking torque of the bottom on the intermediate element by which said bottom is mounted on the middle part.

It is thus ensured that the bottom is not likely to unscrew when it is rotated to adjust its vertical alignment.

• la figure 1 est une vue en perspective et en éclaté de l'ensemble intermédiaire par lequel un fond est monté sur la carrure de la montre, cet ensemble intermédiaire comprenant un élément élastique de blocage et un élément métallique concentrique à l'élément élastique de blocage et sur lequel est vissé le fond;
• la figure 2 est une vue en coupe effectuée au niveau de l'ergot de l'élément métallique d'une pièce d'horlogerie comprenant un ensemble intermédiaire de fixation du fond conforme à l'invention;
• la figure 3 est une vue à plus grande échelle de la région entourée d'un cercle sur la figure 2;
• la figure 4 est une vue en coupe de l'élément élastique de blocage selon l'axe IV-IV de la figure 1;
• la figure 5 est une autre vue en coupe selon l'axe V-V de la figure 1 de l'élément élastique de blocage;
• la figure 6 est une vue en plan du fond de la boîte de montre vissé à bloc sur l'élément métallique de l'ensemble intermédiaire, le fond n'étant pas convenablement aligné par rapport à l'axe vertical 12h-6h de la montre;
• la figure 7 est une vue analogue à celle de la figure 6 sur laquelle on voit que l'ensemble formé par le fond vissé sur l'élément métallique est pivoté par rapport à l'élément élastique de blocage jusqu'à venir dans une position dans laquelle un ergot de l'élément métallique vient en butée contre l'élément élastique de blocage, et
• la figure 8 est une vue analogue à celle de la figure 6 sur laquelle on voit que le fond vissé et l'ensemble intermédiaire par lequel ledit fond est fixé sur la carrure sont pivotés par rapport à la carrure jusqu'à venir dans la position dans laquelle le motif reporté sur la face visible du fond est convenablement aligné par rapport à l'axe vertical.

Other features and advantages of the present invention will emerge more clearly from the following description of an exemplary embodiment of the fixing device according to the invention, this example being given purely by way of illustration and not limitation in connection with the attached drawings in which:

• the figure 1 is a perspective and exploded view of the intermediate assembly by which a bottom is mounted on the middle part of the watch, this intermediate assembly comprising a resilient locking element and a metal element concentric with the elastic locking element and on which is screwed the bottom;
• the figure 2 is a sectional view taken at the lug of the metal element of a timepiece comprising an intermediate fixing assembly of the bottom according to the invention;
• the figure 3 is a larger-scale view of the region surrounded by a circle on the figure 2 ;
• the figure 4 is a sectional view of the elastic locking element along the axis IV-IV of the figure 1 ;
• the figure 5 is another sectional view along the VV axis of the figure 1 the resilient locking member;
• the figure 6 is a plan view of the bottom of the watch case screwed to the block on the metal element of the intermediate assembly, the bottom not being properly aligned with respect to the vertical axis 12h-6h of the watch;
• the figure 7 is a view similar to that of the figure 6 on which it can be seen that the assembly formed by the bottom screwed onto the metal element is pivoted relative to the elastic locking element until it comes into a position in which a lug of the metal element abuts against the elastic locking element, and
• the figure 8 is a view similar to that of the figure 6 on which it is seen that the screwed bottom and the intermediate assembly by which said bottom is fixed on the middle part are pivoted with respect to the middle part until coming into the position in which the pattern carried on the visible face of the bottom is suitably aligned relative to the vertical axis.

The present invention proceeds from the general inventive idea which consists in screwing a bottom not directly on the middle part of a watch case, but on an intermediate assembly forcibly engaged in the lower part of the middle part of the watch, so as to that the bottom, screwed to block on the intermediate assembly, remains captive while being able to be pivoted relative to the middle part of the watch to adjust its alignment with respect to the vertical axis 12h-6h of said watch. Thanks to these features, the present invention provides a timepiece whose middle and bottom do not need to be machined with high precision, which reduces manufacturing costs.

The intermediate assembly according to the invention for fastening a bottom to the middle of a watch is shown in perspective and in the dissociated state on the figure 1 . Designated as a whole by the general numerical reference 1, this set intermediate comprises a metal element 2 which is in the general form of a ring and which is arranged concentrically inside a resilient locking element 4 also substantially shaped ring.

A circular bottom 6 is screwed by a thread 8 which is provided with a ring 10 which is concentrically raised on the inner face of said bottom 6, on the metal element 2 which has to this effect on its inner periphery a screw thread complementary 12.

As is visible on the figure 1 as well as Figures 2 and 3 , the metal element 2 has on its outer periphery an annular shoulder 14 on the upper surface 16 of which bears a flange 18 which extends all along the inner periphery of the elastic locking element 4.

The metal element 2 also comprises a pin 20 which, as will be described in more detail later, is able to pivot by an angle α ( figure 7 ) along a rim 22 in an arc defined by a rim 23 formed on the inner periphery of the resilient locking element 4. The resilient locking element 4 also comprises, formed on its outer periphery, a second flange 24. This outer rim 24 also forms, in the zone where the inner rim 22 does not exist, an arc of circle which is substantially the complement of that formed by said inner rim 22. In other words, the rim 24 angle β ( figure 8 ) which intercepts the arc formed by the second flange 24 has a value such that added to the angle α it produces a sum of 360 °. In the example shown in the figures, the angle α preferably has a value of 270 °, which corresponds to three quarters of the perimeter of a circle, and the angle β thus has a value of 90 ° corresponding to the last quarter of circle. It goes without saying, however, that the angles α and β can assume arbitrary values as long as their sum remains equal to 360 °. This condition on the value of the sum of the angles α and β is imposed by the fact that there may be cases where it is necessary to be able to rotate the bottom 6 of a complete revolution to the extent that it is totally misaligned with respect to the vertical axis 12h-6h of the watch.

The timepiece, for example of the wristwatch type, which is provided with the intermediate assembly 1 according to the invention by which the bottom is mounted on the middle part of the case of the watch is partially shown on the Figures 2 and 3 . Designated as a whole by the general reference numeral 26, this timepiece comprises in particular a middle part 28 surmounted by a telescope 30 which can be screwed on the middle part 28 and which serves to hold a mirror 32. The assembly formed by the bezel 30 and the ice 32 is sealed by the interposition of a seal 34. The middle 28 also has a bore 36 for the passage of a rod 38 on which is fixed in a crown 40. In the example shown in Figures 2 and 3 the wristwatch 26 is of the analog time display type and includes for this purpose a set of hands 42 hours and minutes (a single needle has been shown in the drawing) moving over a It is obvious that the present invention could equally well be applied to a digital time display watch comprising, for example, a liquid crystal cell.

As will be understood from the foregoing, the present invention can be applied to any type of timepiece having a circular bottom and requires, to be able to be implemented, only minor modifications which essentially relate to the shape to be given to the middle part 28 at its lower part where is made the junction with the intermediate assembly 1 fixing the bottom 6 according to the invention.

The elastic locking element 4 forms at its center an annular recess in which the metal element 2 can be engaged. It must then be able to mount this set 1 in the watch 26.

For this purpose, the intermediate assembly 1 formed by the metal element 2 and the elastic locking element 4 is force-fed from the bottom of the watch 26. To facilitate this movement of engagement, the elastic element 4 presents along the entire length of its upper edge 46 located on the outside of the watch 26 an inclined plane 48 which slides on a corresponding inclined plane 50 formed in the lower part of the caseband 28.

The metal element 2 and the elastic element 4 are dimensioned such that, when they are forced into the middle part 28, the metal element 2 radially presses the elastic element 4 against said middle part 28, which has in order to compress said elastic element 4. This elastic element 4 comprises in particular a base 51 which extends all along its lower part and which, in response to the compressive force, will firmly apply the metal element 2 against the bottom 6, ensuring a good maintenance of the constructive assembly. A compression ratio of the base 51 of the order of 20% is preferred. Such a rate causes an increase in frictional forces between the metal element 2 and the elastic element 4 on the one hand, and between the latter and the middle part 28, on the other hand, and therefore determines the torques involved for the adjusting the alignment of the bottom 6 relative to the vertical axis 12h-6h of the watch 26 as will now be described in connection with the Figures 6 to 8 .

For its axial retention, the elastic element 4 comprises all over its outer periphery a projection 52 which penetrates into a groove 54 arranged opposite in the middle 28. The groove 54 has an upper return 56 which overhangs the elastic element 4 and the metal element 2 and which serves as abutment surface.

Once the intermediate assembly 1 according to the invention engaged in the middle 28 of the watch 26, the bottom 6 can be screwed onto the metal element 2. For this purpose, the bottom 6 comprises on its outer surface 58 turned on the side the wrist of the wearer of the watch 26 notches 60 which serve to introduce the tenons of a wrench (not shown) which will allow to completely screw said bottom 6 in the metal element 2.

Note that the bottom 6 advances under the middle 28 of the watch 26 so as to mask the metal element 2 and the elastic element 4 in the view of an observer. The advance 62 of the bottom 6 also serves as abutment surface against the metal element 2 at the end of the screwing of said bottom 6.

On the figure 6 , we see that a pattern 66 (in this case, it is the Greek capital letter omega) carried on the outer surface 58 visible with respect to the bottom 6 by any appropriate technique such as stamping stamping or by engraving is totally misaligned with respect to the vertical axis 12h-6h of the watch 26. The problem therefore consists in straightening the pattern 66 so that it is properly aligned and that the aesthetic appearance of the watch 26 is improved. .

The present invention solves the problem mentioned above. At first, the bottom 6 has been completely screwed by means of the wrench into the metal element 2. It is indeed possible to screw the bottom 6 to a high locking torque because the spigot 20 of the metal element 2 abuts against the inner edge 23 of the elastic element 4 which itself abuts with its outer edge 25 against a pin 67 forcibly engaged in the middle part 28 of the watch 26 (see figure 6 ).

Screwing the bottom 6 is done by turning it in the direction of clockwise. The pattern 66 being misaligned with respect to the axis 12h-6h, we will now rotate, still with the help of the wrench, the assembly formed by the bottom 6 and the metal element 2 on which said bottom 6 is screwed counterclockwise along arrow A ( figure 7 ). The bottom 6 and the metal element 2 which are stationary relative to each other pivot relative to the elastic locking element 4.

Of course, it is necessary that the torque that is necessary to exert to pivot the bottom assembly 6 / metal element 2 is less than the locking torque of said bottom 6 on said metal element 2, otherwise the bottom 6 would risk to unscrew. The adjustment torque of the alignment of the bottom 6 with respect to the vertical axis 12h-6h of the watch 26 is essentially determined by the friction forces which are exerted between the metal element 2 and the elastic element 4 at the base 51 of the latter. As already mentioned above, a compression ratio of the base 51 of the order of 20% is preferred because it has been found that such a rate leads, by the friction forces that it induces between metal element 2 and the elastic element 4, at a base alignment adjustment torque 6 sufficiently high for said bottom 6 is not likely to move unintentionally, but also low enough for turning the bottom 6 counterclockwise, it does not unscrew.

We see on the figure 7 the bottom assembly 6 / metal element 2 has pivoted by an angle α substantially equal to 270 ° relative to the elastic locking element 4 which remains fixed. During this movement, the lug 20 which protrudes from the outer periphery of the metal element 2 has slid along the upper surface of the inner rim 22 of the elastic element 4. The end position of the assembly formed by the bottom 6 and the metal element 2 is determined by the point where the lug 20 abuts against a vertical face 68 of the inner edge 23 which delimits the inner rim 22 of the elastic element 4 ( figure 7 ).

Of course, if, during this movement, the pattern 66 passes through a position in which it is aligned with the vertical axis 12h-6h of the watch 26, it will stop turning the bottom.

In the case shown in the drawing, it is found that arrived in abutment against the elastic locking element 4, the bottom 6 is still not properly aligned. It is therefore necessary to continue to pivot the bottom 6 with the same tightening key that used in the previous step. During this new pivoting movement, the elastic locking element does not remain stationary. Indeed, it is pivoted by the lug 20 of the metal element 4 which abuts against the vertical face 68 of said elastic element 4. Of course, the torque that must be exercised to drive the bottom assembly 6 / element 2 / resilient locking element 4 according to the arrow B ( figure 8 ) counterclockwise must be less than the locking torque of the bottom 6 on the metal element 2 so as not to risk unintentionally unscrewing said bottom 6. This new adjustment torque of the alignment of the bottom 6 relative to the 12h-6h vertical axis of the watch 26 is essentially determined by the frictional forces exerted between the elastic locking element 4 and the middle 28 of the watch 26 at the base 51.

As can be seen from the figure 8 , the pattern 66 carried on the visible face of the bottom 6 is finally suitably aligned with the vertical axis 12h-6h of the watch 26. To obtain this result, it was necessary to rotate again the bottom assembly 6 / metal element 2 / element elastic 4 of a fraction of the angle β.

The problem now arises of how to unscrew the bottom 6 when necessary. For this purpose, the bottom 6 and the intermediate assembly 1 according to the invention are continuously rotated, by which said bottom 6 is mounted on the middle part 28 of the watch case 26 until the elastic element 4 comes to a stop. by a vertical face 70 of its edge 25 which delimits its outer rim 22 against the pin 67 driven into the middle part 28 of the watch 26. The elastic element 4 is thus immobilized, as well as the metal element 2 which stops as to it by its lug 20 against the vertical face 68 of the inner edge 23 of said elastic element 4. The two elements forming the intermediate assembly 1 now being perfectly immobilized relative to the middle part, they oppose sufficient force to the locking torque of the bottom 6 on the metal element 2, which allows to unscrew the bottom 6 by pivoting it in the opposite direction of the operation of the clockwise. This avoids an endless screw effect.

Note that an O-ring 74 is conventionally inserted in an annular groove 76 made at the base of the middle part 28 to ensure the seal between the bottom 6 and said middle part 28.

The metal element 2 may be made of brass. As for the elastic locking element 4, it can be made of a natural or synthetic elastomer, or a thermoplastic material whose compression afterglow rate is well suited to the needs of the present invention.

It goes without saying that the invention is not limited to the embodiment which has just been described and that various modifications and simple variants can be envisaged without departing from the scope of the invention.

In particular, the elastic locking element 4 and the metal element 2 can be introduced into the watch 26 on the ice side, at an early stage of the manufacture of the watch 26, whereas neither the watch movement, neither the switch nor the ice has yet been fitted.

Claims (21)

1. Device for securing a back cover (6) to a middle part (28) of a watchcase (26), the back cover (6) having a screw thread (8) on its outer periphery, this device including an intermediate element (1) forcibly driven in the lower part of the middle part (28) of the watch (26), the back cover (6) being screwed via its screw thread (8) onto the intermediate element (1) which has, for this purpose, on its inner periphery, a complementary screw thread (12), this device being characterized in that this intermediate element (1) is capable of being forced to pivot with respect to the middle part (28) of the watch (26) to adjust the alignment of said back cover (6) with respect to the vertical 12 o'clock - 6 o'clock axis of said watch (26) when the back cover (6) is completely screwed onto this intermediate element (1).
2. Securing device according to claim 1, characterized in that the intermediate element (1) includes a resilient blocking element (4) which is compressed transversely, and a metal element (2) which is arranged concentrically inside of the resilient blocking element (4), the back cover (6) being screwed onto the metal element (2) so that, when the back cover (6) is completely screwed onto said metal element (2), this metal element (2) can be forced to pivot by an angle of less than 360° with respect to the middle part (28) of the watch (26), by sliding on the resilient blocking element (4) which remains fixed up to a point where the metal element (2) abuts against said resilient element (4).
3. Securing device according to claim 2, characterized in that the resilient blocking element (4) can be forcibly pivoted by an angle of less than 360° by sliding on the middle part (28) of the watch (26) and being driven to pivot by said metal element (2).
4. Securing device according to any one of claims 2 or 3, characterized in that the alignment adjustment torque of the back cover (6) with respect to the vertical 12 o'clock - 6 o'clock axis of the watch (26), which is determined by the compression set of the resilient blocking element (4) is less than the screwing torque of said back cover (6) on the metal element (2).
5. Securing device according to any one of claims 2 to 4, characterized in that the metal element (2) is able to pivot by an angle (α) with respect to the resilient blocking element (4) and in that said metal element (2) and said resilient blocking element (4) are able to pivot together by an angle (β) whose value is such that, when added to that of the angle (β) it produces a sum of 360°.
6. Securing device according to claim 5, characterized in that the angle (α) is equal to 270° and the angle (β) is equal to 90°.
7. Securing device according to any one of claims 6 or 7, characterized in that the resilient blocking element (4) has a first rim (22) in the shape of an arc of a circle arranged on its inner periphery and a second rim (24), also in the shape of an arc of a circle, arranged on its outer periphery which is complementary to that formed by the inner rim (22).
8. Securing device according to claim 7, characterized in that the metal element (2) includes a snug (20) which projects from its outer periphery and which is able to pivot by the angle (α) along the inner rim (22) of the resilient blocking element (4).
9. Securing device according to any one of claims 2 to 8, characterized in that the resilient blocking element (4) includes a base (51) which extends along its lower part and which is compressed between the metal element (2) and the middle part (28) of the watch (26) when the back cover (6) is screwed onto said metal element (2).
10. Securing device according to any one of claims 2 to 9, characterized in that, in order to hold it axially, the resilient element (4) includes a projecting portion (52) which penetrates an opposite groove (54) arranged in the middle part (28).
11. Securing device according to claim 10, characterized in that the groove (54) has a return portion (56) which overhangs the resilient element (4) and the metal element (2) so as to prevent the latter from moving axially upwards.
12. Securing device according to any one of claims 2 to 11, characterized in that the metal element has on its outer periphery an annular shoulder (14) on the upper surface (16) of which a collar (18), which extends along the inner periphery of the resilient element (4) abuts.
13. Securing device according to any one of claims 2 to 12, characterized in that, in order to facilitate the forcible introduction of the intermediate assembly (1) from the bottom of the middle part (28) of the watch (26), the resilient element (4) has over the entire length of its upper edge (46) located on the outer side of the watch (26), a sloping plane (48) which slides on a corresponding sloping plane (50) arranged in the lower part of the middle part (28).
14. Securing device according to any one of claims 2 to 13, characterized in that the back cover (6) moves forward under the middle part (28) of the watch (26) so as to act as a support surface for the metal element (2) in order to prevent the latter from moving axially downwards.
15. Securing device according to any one of claims 2 to 14, characterized in that the resilient blocking element (4) is able to abut against a pin (67) forcibly driven in the middle part (28) of the watch (26).
16. Securing device according to any one of claims 1 to 15, characterized in that the back cover (6) includes, on its outer surface (58) turned to the side of the wrist of the person wearing the watch (26), notches (60) which are used for introducing the studs of a chuck key.
17. Securing device according to any one of claims 1 to 16, characterized in that an O ring (74) is inserted into an annular groove (76) made at the base of the middle part (28) to guarantee sealing between the back cover (6) and said middle part (28).
18. Assembly method for a back cover (6) by means of the securing device according to any one of the preceding claims, characterized in that, after the back cover (6) has been completely screwed in the clockwise direction onto the metal element (2), the assembly formed by the back cover (6) and the metal element (2) is pivoted in the anticlockwise direction in order to adjust the alignment of said back cover (6) with respect to the vertical 12 o'clock - 6 o'clock axis of the watch (26).
19. Assembly method according to claim 18 depending of any one of claims 2 to 17, characterized in that the assembly formed by the back cover (6) and the metal element (2) is pivoted by at least a fraction of the angle (α) by sliding on the resilient blocking element (4) which remains fixed, and in that, if the back cover (6) is still not properly aligned with respect to the vertical 12 o'clock - 6 o'clock axis of the watch (26) when said assembly has pivoted by the angle (α), it drives to pivot the resilient blocking element (4), which slides on the middle part (28) by at least a fraction of the angle (β), which is the complement over 360° of the angle (α).
20. Method according to any one of claims 18 or 19 depending of any one of claims 8 to 18, characterized in that the metal element (2) drives the resilient blocking element (4) to pivot via its snug (20) which abuts against said resilient element (4).
21. Method according to claim 20, characterized in that, in order to unscrew back cover (6), the assembly formed by said back cover (6), the metal element (2) and the resilient blocking element (4), is pivoted in the anticlockwise direction until the resilient element (4) is immobilised against a pin (67) forcibly driven into the middle part (28) of the watch (26), the metal element (2) being immobilised in turn by abutting via its snug (20) against said resilient element (4), so that the back cover (6) can then be unscrewed.

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