EP1151357B1 - Method for fixing a crown screwed on a watch case and watch case equipped with same - Google Patents

Abstract

The invention concerns a method for assembling a screwed crown on a watch case, characterized in that it includes the following steps: providing a crown with an inner threading the position of which is set with respect to the logo arranged on the front face of the crown; providing an intermediate tube including two threaded sections; mounting said intermediate tube in a smooth through hole passing through the case and wedging it on an assembling jig to arrange the thread start of the tube intended to accommodate the internal screw thread of the crown in an angular position such that when the crown is screwed as far as possible onto the tube said logo or said mark is located in a determined position; providing a nut and immobilizing the tube in said angular position.

Description

The present invention relates to a method of mounting a screwed crown, such as a winding crown, on a watch case.

More particularly, the invention relates to such a mounting method for indexing the position of a screwed crown on a watch case so that a logo affixed to the face of said crown is always easily returned to a position or orientation determined after have been unscrewed.

The manufacture and assembly of crown screwed on watch cases are well known. However, the methods of mounting these rings have a significant disadvantage. Indeed, known assembly methods do not make it possible to ensure that the crown is brought back in a specific orientation with respect to the box after unscrewing, which considerably affects the aesthetics of the box when a mark or a logo is affixed to one side of the crown. This situation is of course unacceptable when these crowns equip luxury and high quality products.

The patent CH 662 697 discloses a watch case comprising a passage for the rod of a manual movement control mechanism passing through a box tube screwed into the body thereof. The tube has, externally, a shoulder having a frustoconical bearing surface annularly supported on the box body in order to prevent untimely loosening of the tube.

The patent CH347 136 discloses a winding crown comprising a core for receiving the winding stem. A plate rests on the upper face of the core and a sleeve surrounds the core and closes against it the wafer, may carry an inscription, for example a trademark or trade.

The main object of the present invention is to overcome the drawbacks of the abovementioned prior art by providing a simple and economical method for mounting a crown comprising a logo or a mark which systematically allows the crown to be screwed back into a position where orientation determined after being unscrewed.

• se munir d'une couronne ayant un taraudage intérieur indexé par rapport au logo disposé sur la face avant de la couronne;
• se munir d'un tube intermédiaire comportant deux tronçons filetés,
• monter ledit tube intermédiaire dans un trou lisse traversant de la boite en le calant sur un gabarit pour disposer l'entrée de filet du tube destiné à recevoir le taraudage de la couronne dans une position angulaire telle que lorsque la couronne est vissée en butée sur le tube ledit logo se trouve dans une position déterminée,
• se munir d'un écrou et immobiliser le tube ladite position angulaire.

For this purpose, the subject of the invention is a method for mounting a screw-locked crown on a watch case, characterized in that it comprises the following steps:

• provide a crown with internal tapping indexed to the logo on the front face of the crown;
• provide an intermediate tube with two threaded sections,
• mounting said intermediate tube in a smooth hole passing through the box by wedging it on a template to arrange the thread inlet of the tube intended to receive the tapping of the ring in an angular position such that when the ring is screwed in abutment on the tube said logo is in a determined position,
• take a nut and immobilize the tube said angular position.

• se munir d'une bague taraudée;

According to an advantageous characteristic of the invention, the realization of the indexed tapped crown comprises the following steps:

• bring a threaded ring;

• se munir d'une bague taraudée;
• positionner à l'aide d'un gabarit ladite bague de manière à indexer ledit taraudage par rapport au logo ou à la marque porté sur la face de ladite couronne et
• immobiliser ladite bague sur ladite couronne dans ladite position indexée.

According to an advantageous characteristic of the invention, the mounting of the indexed tapped crown comprises the following steps:

• bring a threaded ring;
• positioning with said template said ring so as to index said tapping relative to the logo or the mark worn on the face of said crown and
• immobilizing said ring on said ring in said indexed position.

The invention also relates to a watch case comprising a screwed crown provided with an internal thread, the front face of said crown comprising a logo or a mark, an intermediate tube comprising a threaded outer portion for receiving said tapping, said intermediate tube being fixedly mounted in the box, the latter being characterized in that the inner thread of the ring is indexed relative to the logo or to the mark and in that the intermediate tube is mounted in the box in order to be angularly oriented relative to the box and fixed on the box in a determined angular position

According to an advantageous characteristic, the ring comprises on the opposite side to said front face an annular groove in which is fixedly mounted a ring provided with an internal thread. According to another characteristic, the ring is welded to the ring.

According to yet another feature, the intermediate tube is mounted in a smooth hole in the box and is secured to the box by means of a nut.

• la figure 1 montre une vue en coupe de la couronne montée selon le procédé de l'invention, et
• la figure 2 montre une vue éclatée de la couronne avant la mise en oeuvre du procédé de l'invention.

Other features and advantages of the present invention will appear in the following description of a preferred embodiment, presented by way of non-limiting example with reference to the accompanying drawings, in which:

• the figure 1 shows a sectional view of the crown mounted according to the method of the invention, and
• the figure 2 shows an exploded view of the crown before the implementation of the method of the invention.

Will be described below in connection with Figures 1 and 2 the method of mounting a screwed crown 1 on a watch case 2 which is only partially shown in the drawing. The screwed crown 1 comprises a first portion formed of a head 3 having a front face 4 on which is affixed a logo or a mark 5 which, in the screwed position of this ring, has a defined angular orientation with respect to the box 2 This first part is connected to the movement in a conventional manner. The head 3 is provided on the opposite side to the end face 4 of an annular groove 7 which receives a ring 8 internally threaded 9. The ring 8 is positioned in the groove 7 with the help of a template (not shown) in a way to indexing said tapping 9 relative to the logo 5 and is immobilized in the groove 7 in said indexed position. The indexing operation is preferably performed using a camera and the immobilization is performed by a welding operation for example a laser welding. The logo 5 therefore has a determined angular position and is known with respect to the entry of the tapping 9. The ring further comprises a second part connected to the box 2. This second part comprises an intermediate tube 10 and a nut 11 intended to immobilize the tube 10 in a defined angular position on the box 2. The tube 10 comprises two externally threaded sections 12 and 13 which cooperate respectively with the nut 11 and the indexed tapping 9. The tube 10 is freely mounted in a through hole 14 smooth of the box. The tube 10 is then wedged using a template (not shown) to arrange the inlet of the thread 13 in an angular position such that when the ring 1 is screwed in abutment on the tube 10, said logo 5 is located in an angular position determined with respect to the box. Once this calibration operation is completed, the tube 10 is immobilized by the nut 11.

Note that the crown can be already screwed fully on the tube 10 during its positioning, the indexing was then not on the entry of the thread 13 but directly on the orientation of the logo before the locking of the tube 10 to using the nut 11.

Claims (6)

1. Method of assembling a screw-in crown (1) on a watchcase (2), characterized in that it includes the following steps:

   - taking a crown (1) that has an inner thread (9) indexed relative to a logo (5) or sign made on the front face (4) of the crown;

   - taking an intermediate tube (10) that includes two external threaded sections (12, 13),

   - assembling said intermediate tube (10) in a smooth hole (14) passing through the case (12) by abutting it against a template, so as to arrange the thread start of the tube that receives the crown thread (9) in an angular position, such that, when the crown is screwed into the tube said logo is in a determined position, and

   - taking a nut (11) and immobilising the tube (10) in said angular position.
2. Assembly method according to claim 1, characterized in that the assembly of the crown with an indexed inner thread includes the following steps:

   - taking a threaded ring (8),

   - positioning said ring (8) using a template so as to index said thread relative to said logo (5) or to said sign carried on the face of said crown, and

   - immobilising said ring (8) on said crown in said indexed position.
3. Watch case including:

   - a screw-in crown (1) with an inner thread (9), the front face (4) of said crown (1) including a logo or sign (5),

   - an intermediate tube (10) including an external threaded section (13) for receiving said thread, said intermediate tube (10) being fixedly assembled in said case (2),

   characterized in that the inner thread of the crown (9) is indexed relative to the logo or sign (5) and in that the intermediate tube (10) is mounted on the case such that said tube can be angularly oriented relative to the case and secured thereto in a determined angular position.
4. Watch case according to claim 3, characterized in that, on the opposite side to said front face, the crown (1) includes an annular groove (7) in which a ring (8), provided with said inner thread (9), is fixedly assembled.
5. Watch case according to claim 4, characterized in that said ring (8) is welded to said crown (17).
6. Watch case according to any of claims 3 to 5, characterized in that said intermediate tube (10) is assembled in a smooth hole (14) arranged in said case (2) and in that it is secured to said case in the determined angular position by means of a nut (11).

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