EP1727005A1 - Screwing crown and method to assembly such a crown on a watch case - Google Patents

Abstract

The crown has a tube (20) that is placed in a tube (30) which is formed of two parts. One of the parts of the tube (30) is fixed on a watchcase and the other part of the tube projects from the watchcase. A threaded ring (40) is provided for free rotation on the tube (30) and cooperates with a thread of an inner wall. A screw (46) is provided for blocking the rotation of the ring with respect to the tube (30). A sealing unit is constituted by a joint (42) and arranged between the tubes (20, 30). Independent claims are also included for the following: (1) a method for orienting a crown (2) a tool for mounting a crown by a crown orienting method.

Description

Technical area

The present invention relates to the field of watchmaking. More particularly, it relates to a screw-type watch crown, such as a winding crown. The invention also relates to a method of assembling such a crown on a watch case, for orienting the crown in a specific position.

State of the art

The manufacture and assembly of screw-on crowns on watch cases are well known. For aesthetic reasons, it is essential, when the external face of the crowns bears a mark or a logo, to be able to guarantee that the crown is brought back in a specific orientation relative to the box when it is in the target position.

Document is known WO 01/40881 a screwed crown comprising a first part formed of a head having a front face on which is affixed a logo or a mark which, in the screwed position of this ring, has a specific angular orientation relative to the box. This first part is connected to the movement in a conventional manner. The head is provided on the side opposite the front face, an annular groove which receives an internally threaded ring. This ring is positioned relative to the head using a template so as to index the tapping relative to the logo which has, therefore, a determined angular position and known with respect to the entry of the tapping.

The crown further includes a second portion connected to the watch case. This second part comprises an intermediate tube and a nut intended to immobilize the tube on the box in a position determined angle. The tube comprises two externally threaded sections which cooperate respectively with the nut and the indexed tapping of the ring gear.

The tube is freely mounted in a smooth through hole in the box. This tube is then wedged using a template to arrange the thread entry in an angular position such that, when the ring is screwed abutting on the tube, the logo is in a defined angular position relative to the box. Once this calibration operation is completed, the tube is immobilized by the nut.

In addition to a complex assembly, such a device has an additional disadvantage. Indeed, the positioning of the tube is performed according to the particular crown with which it is mounted, the relative positions of the two threaded portions being determined and very difficult to change. However, if the crown is inadvertently damaged during assembly or if, in use, it is damaged and a change of crown has to be made, it is then necessary to remove the tightness of the tube to be able to reposition it in relation to the box. The watchmaker who makes this repair must again seal and test, these operations being particularly tedious.

The present invention aims to provide a screw-in crown that can be oriented and reoriented easily in a manner defined with respect to the box, while ensuring a perfect seal at the interface between the crown and the box.

Disclosure of the invention

• une tête ayant une face frontale dotée d'un logo à géométrie non circulaire et une face latérale présentant une paroi intérieure munie d'un filetage, et
• un premier tube solidaire de la tête et destiné à être relié cinématiquement audit mouvement.

More specifically, the invention relates to a screw-in crown intended to take place on a watch case inside which a timepiece movement takes place, comprising:

• a head having a front face with a non-circular geometry logo and a side face having an inner wall with a thread, and
• a first tube secured to the head and intended to be kinematically connected to said movement.

• un deuxième tube, dans lequel prend place ledit premier tube, formé d'une première partie destinée à être monté à demeure sur la boite de montre et d'une deuxième partie dépassant de la boite,
• une bague filetée montée libre en rotation sur ladite deuxième partie et destinée à coopérer avec le filetage de ladite paroi intérieure, et
• un organe de blocage destiné à bloquer la rotation de ladite bague par rapport audit tube.

In order to guarantee a perfect seal while allowing to adjust the orientation of the logo, the screw-in crown comprises, in addition:

• a second tube, in which takes place said first tube, formed of a first portion to be permanently mounted on the watch case and a second portion protruding from the box,
• a threaded ring rotatably mounted on said second portion and intended to cooperate with the threading of said inner wall, and
• a locking member for locking the rotation of said ring relative to said tube.

According to a first embodiment, the locking member is formed of a nut cooperating with the threaded ring and intended to rest on the watch case. The second part of the second tube has a shoulder against which the nut pushes the ring.

• un premier élément de forme globale tubulaire, se terminant par une première extrémité dont le profil est dimensionné pour s'adapter sur l'écrou et par une deuxième extrémité présentant une structure, qui permet d'agir sur sa rotation,
• un deuxième élément de forme globale tubulaire de diamètre légèrement inférieur au diamètre intérieur du premier élément, et se terminant par une première extrémité qui peut se visser sur la bague filetée, et par une deuxième extrémité présentant une structure, qui permet d'agir sur sa rotation l'élément, ladite première extrémité laissant un espace libre entre la bague et elle, et
• un troisième élément de forme globale cylindrique de diamètre légèrement inférieur au diamètre intérieur du deuxième élément, et se terminant par une première extrémité qui peut se visser sur la bague filetée dans l'espace laissé libre par ledit deuxième élément, et par une deuxième extrémité qui présente une structure qui permet d'agir sur sa rotation.

A tool is proposed for mounting a crown obtained according to this first embodiment. It comprises:

• a first element of overall tubular shape, terminating in a first end whose profile is sized to fit on the nut and in a second end having a structure, which makes it possible to act on its rotation,
• a second element of overall tubular shape of diameter slightly smaller than the inside diameter of the first element, and terminating in a first end which can be screwed onto the threaded ring, and by a second end having a structure, which makes it possible to act on its rotating the element, said first end leaving a free space between the ring and it, and
• a third element of cylindrical overall shape with a diameter slightly smaller than the inside diameter of the second element, and terminating in a first end which can be screwed onto the threaded ring in the space left free by said second element, and by a second end which has a structure that allows to act on its rotation.

According to a second embodiment, the ring comprises, at its base supported against the box, a flange. The locking member is a plate tight against the box, provided with an opening whose diameter is slightly greater than that of the threaded ring, so as to let the latter while resting on the edge.

According to a third embodiment, the second part of the second tube comprises a shoulder, a space being left free between the threaded ring and the shoulder. The locking member is formed of a ring gear fixed relative to the box and a toothing which is provided with the threaded ring. The toothing may move between a first position in which it cooperates with the ring gear and a second position in which it is free relative to this ring gear.

• montage de la couronne, la bague filetée étant maintenue par l'organe de blocage,
• définition de l'orientation initiale de ladite bague filetée par rapport audit deuxième tube,
• démontage de la couronne, la bague filetée restant maintenue par l'organe de blocage,
• libération de la bague filetée de l'organe de blocage,
• orientation de la bague filetée par rapport audit deuxième tube,
• maintien de la bague filetée par l'organe de blocage dans la position obtenue lors de l'étape précédente, et
• montage de la couronne.

The invention also relates to a method of orienting a screw-in crown as defined above, comprising the following steps:

• mounting of the ring, the threaded ring being held by the locking member,
• defining the initial orientation of said threaded ring with respect to said second tube,
• disassembly of the ring, the threaded ring remaining held by the locking member,
• release of the threaded ring from the locking member,
• orienting the threaded ring with respect to said second tube,
• maintaining the threaded ring by the locking member in the position obtained in the previous step, and
• mounting of the crown.

Brief description of the drawings

• les figures 1 et 2 sont des vues en coupe, respectivement assemblée et éclatée, d'une couronne à visser selon l'invention,
• la figure 3 illustre un procédé d'assemblage selon l'invention, et
• les figures 4 et 5 représentent différentes variantes de l'invention.

Other details will appear more clearly on reading the description which follows, made with reference to the appended drawing, in which:

• FIGS. 1 and 2 are sectional views, respectively assembled and exploded, of a screw-in crown according to the invention;
• FIG. 3 illustrates an assembly method according to the invention, and
• Figures 4 and 5 show different variants of the invention.

Mode (s) of realization of the invention

FIGS. 1 and 2 show a screw-in crown 10 mounted in a watch case 12 intended to receive a clockwork movement.

Conventionally, the crown according to the invention comprises a head 14 having a front face 16 with a pattern or logo. This mark or logo has a non-circular geometry. It is therefore preferable that the crown, in the screwed-in position, has an angular orientation determined with respect to the box 12.

The ring 10 is kinematically connected to a movement control rod, in particular a winding stem, via a part 18 called piston. Conventionally, the head 14 is connected to this piston 18 by connecting means comprising a first tube 20 secured to the head 14 and sliding on the piston 18, and a spring member 22 which ensures the engagement of the head 14 and the control rod when the ring 10 is in the unscrewed position.

The head 14 also has a side face 24 which extends on the end of the tube 20, parallel to it, and whose outer wall is provided with grooves. The side face 24 defines, between the tube 18 and its inner wall, a space 26 whose role will appear later. This inner wall is provided with a threading 28 intended, as will be better understood hereinafter, to screw the crown 10.

To assemble the ring 10 to the box 12, a second tube 30 is driven into a smooth hole 32through the middle of the box 12 and defining an edge 36. Conventionally, the tube 30 can also be screwed into the box, the hole 32 then having a thread. The tube 30 is permanently positioned, perfectly sealed, by usual techniques, in particular by welding or gluing.

A part of this tube 30, said external, protrudes from the box and has a first shoulder 34 intended to rest on the middle, at the edge 36. The end of the outer portion also comprises a second shoulder 38 whose role will appear later. The outer part is smooth and has no threading.

A threaded ring 40 is freely fitted on the outer portion of the tube 30. Advantageously, the ring 40 occupies the entire zone delimited by the second shoulder, that is to say the zone between the two shoulders 34 and 38. It is and perfectly positioned in the axis of the rod 18, between the edge of the middle and the second shoulder 38.

In order to guarantee the tightness of the device, sealing means are positioned between the first 20 and the second 30 tubes. More specifically, a seal 42 is housed in a groove 44 formed inside the second tube 30.

The ring 40 is free to rotate on the outer portion of the tube, it can be oriented freely relative to the latter. In particular, the entry of its thread can be positioned precisely. It is then necessary to be able to maintain the position of the ring 40 in position.

Thus, a locking member is arranged to position and maintain the ring relative to the tube 30. In the embodiment of Figures 1 and 2, this locking member is constituted by a nut 46 which is screwed on the thread of the ring 40, on the side of the middle part. When the nut 46 is tightened, it pushes the ring 40 against the second shoulder 38, thus keeping it in position.

When the ring 10 has been assembled on the rod 18 in a conventional manner, the threading 28 can then collaborate with the threaded ring 40 to screw or unscrew the ring 10 which can drive the rod when it is in the unscrewed position.

Advantageously, the smooth hole 32 opens, outside the box, in an annular housing 48 of diameter greater than that of the ring 10. Thus, the first shoulder 36 is at depth relative to the edge of the middle part 12 and the nut 46 rests on the bottom of the housing 48. Thus, the prominence of the assembly is decreased.

In a variant not shown, the ring 40 has two portions of different threads. The threading of the portion on which the crown 10 is screwed has a greater pitch than that of the portion cooperating with the nut 46. Thus, the unscrewing of the crown is easily done for the wearer, with a small rotation of the order of one or two turns, while the Tightening torque of the nut can be precisely controlled.

When the crown 10 has been mounted, it is necessary to adjust the orientation of the logo. To do this, a three-element tool 50, 52, 54, 56 is illustrated in FIG. 3, which includes an enlarged view of the essential elements. This tool and its use are described below.

The first step in adjusting the orientation of the logo of the crown is to define the initial orientation of the threaded ring 40. The ring 10 is mounted on the rod 18 and screwed completely, as would the user. The angular deviation of the logo from the desired position is then raised. The ring 10 is then dismounted. The ring 40 being blocked by the nut 46, these operations are done without it moving.

The second step is to orient the threaded ring 40 in the desired position. We understand the difficulty of this operation, since in a small space, it must be possible to release the ring of the locking member, orient it accurately and block it again without turning. The tool mentioned above aims to solve this problem.

The first element 52 of the tool is of tubular overall shape. It is hollow and ends with a first end 52a whose profile is sized to fit on the nut. If the case has a housing 48, this end 52a adapts, in addition, to the shape of the housing. At its second end 52b, the element has a wider portion, possibly knurled, which keeps it rotating. The first element 52 is mounted on the nut.

The second element 54 of the tool is also tubular. For the most part, its outside diameter is slightly smaller than the inside diameter of the first element 52. It is hollow and ends with a first end 54a which can be screwed onto the threaded ring. This first end leaves a free space between the ring and the element 54. its second end 54b, the element has a wider portion, optionally knurled, which keeps it rotating. The second element is introduced into the first, and is screwed onto the threaded ring 40, to the vicinity of the nut 46 leaving a gap.

The third element 56 of the tool is of cylindrical overall shape. Its outside diameter is slightly less than the inside diameter of the second element 54. It ends with a first end 56a which can be screwed onto the threaded ring 40 in the space left free by the second element 54. At its second end 56b, the element has a structure, possibly a knurling, which allows its screwing on the ring. The third element 56 is inserted into the second 54, screwed onto the ring 40 while the element 54 is retained in rotation, until the element 56 is locked on the element 54. In this way, the threaded ring 40 and the second 54 and third 56 elements are made integral.

By action on the first element 52 and thanks to the game left during the mounting of the second element 54, the nut 46 is unscrewed. The threaded ring 40 is thus released. It is then easy to orient it by rotating the raised angle in the first step, the assembly consisting of the threaded ring 40 and the second 54 and third 56 elements.

The nut 46 is then screwed and locked by action on the first element 52. The position of the threaded ring 40 is ensured during this operation by maintaining the assembly formed by the ring 40 and the second 54 and third 56 elements.

The elements 54 and 56 can then be unscrewed, then the first element 52 is removed. The crown 10 is then raised and screwed and its orientation is controlled. If necessary, the aforementioned operations are repeated.

Figure 4 shows a first variant of the locking member of the threaded ring 40. The housing 48 formed in the middle occupies a more important place. The ring 40 comprises, at its base supported against the middle part, a flange 60 which extends on the bottom of the housing 48. A plate 62 whose contour is adjusted, is disposed in the housing 48. It is provided with an opening whose diameter is slightly greater than that of the ring 40, so as to let the latter while bearing on the flange 60. Two screws 64 cooperate with two tapped holes in the middle part to press the plate on the flange 60, thus keeping the ring 40 rotating.

As above, to adjust the orientation of the ring 40, its initial orientation is raised. Then, after disassembly of the ring, the plate 62 is loosened to properly orient the ring 40. The latter is again locked and the crown is raised.

The screws 64 could also bear directly on the flange 60 of the ring, preferably without passing through it, simply by crushing the edge of the flange 60 between a portion of the head of the screw and the middle part. In this way, it is not necessary to completely remove the screws 60 to allow rotation of the ring 40.

Figure 5 illustrates an additional variant for the locking member of the threaded ring 40 and has an enlarged view of a portion of this member. The threaded ring 40 is lower than in the above versions and does not occupy the entire area between the shoulders 36 and 38. A space 68 is thus left free between the ring and the second shoulder. It is intended to receive a resilient split ring 70, circlip type. The threaded ring 40 has an internal toothing 72 located at one of its ends.

The tube 30 is not smooth and has on its outer periphery a ring gear 74 juxtaposed along the axis of the rod 18 to a groove 76, located between the ring gear 74 and the space 68. The ring gear 74 can also be directly juxtaposed to the space 68, which then plays the role of the groove 76.

The threaded ring 40 is positioned on the tube 18. When the teeth of one and the other cooperate, the ring 40 is kept rotating. The circlip 70 is then placed in the space 68, resting on the second shoulder 38 to hold the ring 40 in the direction of the axis of the tube. The teeth are kept engaged and the ring is locked.

To unlock the ring 40, simply remove the circlip 70. It can then be moved axially, so that its toothing 72 is engaged in the groove 76 or in the space 68. The ring 40 is oriented and repositioned so that its toothing 72 is again engaged with that 74 of the tube 40. The circlip 70 is then put back in place to maintain the whole.

As above, to adjust the orientation of the ring 40, its initial orientation is raised. Then, after disassembly of the crown, the circlip 70 is removed in order to properly orient the ring 40. The latter is again blocked by raising the circlip 70 and the crown is raised.

The toothed portion 72 which is provided with the threaded ring could also extend on the outside and cooperate with a toothing formed directly in the box 12, disposed in the housing 48.

Thus is proposed a device for defining precisely the orientation of a screw-in crown, without prejudice to its sealing with the watch case. The device which has just been described can be easily adapted to any type of screw-in crown, in particular that of the internal screw-type type, the essence of the invention being to dissociate the member ensuring the tightness of the device and that ensuring screwing the crown.

Claims (12)

Screw-in crown (10) intended to take place on a watch case (12) inside which a timepiece movement takes place, comprising: a head (14) having a front face (16) provided with a non-circular geometry logo and a lateral face (24) having an inner wall provided with a thread, and a first tube (20) integral with the head (14) and intended to be kinematically connected to said movement, characterized in that it further comprises: - a second tube (30), in which takes place said first tube (20), formed of a first portion intended to ensure its permanent attachment to the watch case and a second portion protruding from the box, a threaded ring (40) rotatably mounted on said second portion (30) and intended to cooperate with the threading of said inner wall, and - A locking member for locking the rotation of said ring relative to said tube. Screw-in crown according to claim 1, characterized in that said locking member is formed of a nut (46) cooperating with said threaded ring (40) and intended to rest on the watch case (12), said second part of the second tube (30) having a shoulder (38) against which said nut (46) pushes said ring (40). Screw-in crown according to claim 2, characterized in that said ring (40) is sized to occupy the entire area of the second portion of said second tube (30) delimited by said shoulder (38). Screw-in crown according to one of claims 2 and 3, characterized in that said ring has two portions of different threads. Screw-in crown according to claim 1, characterized in that said ring (40) comprises, at its base supported against the box (12), a flange (60) and in that said locking member is a plate (62) pressed against the box (12), said plate (62) being provided with an opening whose diameter is slightly greater than that of the ring (40), so as to let it pass while bearing on said flange (60). Screw-in crown according to claim 1, characterized in that said second portion of the second tube (30) has a shoulder (38), a space (68) being left free between said ring (40) and said shoulder (38), and in that said locking member is formed of a ring gear (74) fixed relative to the box (12), and a toothing (72) which is provided with said threaded ring (40), said toothing (72) being able to evolve between a first position in which it cooperates with said ring gear (74) and a second position in which it is free relative to said ring gear (74). Screw-in crown according to claim 6, characterized in that an elastic split ring (70) can be removed from said gap (68) to allow passage of said toothing (72) from its first to its second position, and can be inserted in said space (68) to allow passage of said toothing (72) from its second to its first position. Screw-in crown according to one of claims 6 and 7, characterized in that said ring gear (74) is disposed on said second tube, juxtaposed with a groove (76). Screw-in crown according to one of claims 6 and 7, characterized in that said ring gear (74) is arranged on the box (12). Screw-in crown according to one of Claims 1 to 9, characterized in that sealing means (42) are arranged at the interface between said first and second tubes. Method for orienting a screw-in crown according to one of claims 1 to 10, characterized in that it comprises the following steps: - mounting of the ring (10), the threaded ring (40) being held by the locking member, defining the initial orientation of said threaded ring (40) with respect to said second tube (30), - disassembly of the ring (10), the threaded ring (40) remaining held by the locking member, - release of the threaded ring (40) of the locking member, - orientation of the threaded ring (40) relative to said second tube, - Holds the threaded ring (40) by the locking member in the position obtained in the previous step, and - mounting of the crown (10). Tool for mounting a ring according to one of claims 2 to 4 by the method according to claim 11, characterized in that it comprises: a first element (52) of tubular overall shape, ending in a first end (52a) whose profile is sized to fit on the nut (46) and a second end (52b) having a structure, which allows to act on its rotation, a second element (54) of tubular overall shape with a diameter slightly smaller than the inside diameter of the first element (52), and terminating in a first end (54a) which can be screwed onto the threaded ring (40), and by a second end (54b) having a structure which makes it possible to act on its rotation to maintain it in rotation, said first end leaving a free space between the ring and it, and - A third element (56) of cylindrical overall shape with a diameter slightly smaller than the inside diameter of the second element, and ending with a first end (56a) which can be screwed onto the threaded ring (40) in the space left free by said second element, and by a second end (56b) which has a structure which makes it possible to act on its rotation.

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