CH719033A2 - Watch assembly made up of a case incorporating a movement and a removable outer casing. - Google Patents

Abstract

The watch assembly comprises a waterproof case (4), an outer covering part (6) configured to be able to surround the waterproof case and a removable assembly system for these two main parts which comprises an elastic element (8) formed by an elastomeric seal configured to be able to be arranged in a groove (30) machined in a side wall (32) of the waterproof casing or in an inner wall (36) of the outer trim part (6) and to present, once fitted in place in the groove, a protruding part out of this groove. The elastomer seal (8) is arranged to be able to undergo, during assembly or disassembly of the external trim part (6) and the sealed casing (4), an elastic deformation allowing the axial force to insert the sealed box in the outer trim part, so that the protruding part finally comes to be placed at least partly in a hollow (40) or behind a shoulder (38) of the inner wall of the outer trim part (6 ) respectively the side wall (32) of the waterproof case (4), to hold the two main parts of the watch assembly together.

Description

Technical field of the invention

The invention relates to a watch having a casing formed of two distinct parts (apart from the bracelet) which are arranged in such a way as to allow their assembly and their disassembly manually, without specific tools.

[0002] More particularly, the invention relates to a watch assembly which is formed by two main parts respectively forming a sealed case, in which is incorporated a watch movement and a time display, and a removable outer trim part which surrounds the waterproof case when the two main parts are assembled.

Technology background

[0003] Various watchmaking assemblies corresponding to the watchmaking assembly defined above have been proposed in the past for various reasons, in particular to allow the visible dressing of a watch to be varied or to favor a system for attaching a strap to the case allowing a user to easily change such a bracelet.

[0004] In particular, patent applications CH 5991/70 and FR 2,122,547 and patent CH 538,139 may be cited, in which an outer caseband-bezel is removably mounted on a sealed case by means of a spring. -thread which is introduced into a groove of one of the two parts from which it protrudes over certain angular sections by coming into axial abutment against an abutment of the other part. A similar assembly concept is proposed in the patent application CH 9337/72 in which there is provided a relatively complex leaf spring which is arranged in a groove of the internal middle part forming the sealed case and which has stamped portions coming from s insert slightly into a corresponding groove, machined inside the outer caseband-bezel. These achievements are relatively fragile. Indeed, the wire spring and the leaf spring must be handled with care because they can easily be deformed and even twisted before being introduced into the receiving groove and then during their introduction into such a groove. Once deformed or twisted, these springs are generally unusable. Then, several assembly and disassembly of the two main parts by a user is highly likely to damage such a wire spring or leaf spring. Moreover, for such a system to ensure a stable and sufficiently precise assembly, the elastic force of the spring to be overcome during assembly or disassembly of the two main parts must be relatively strong. Finally, no safety means prevents accidental dismantling of the two main parts.

Summary of the invention

The object of the present invention is to solve in particular the drawbacks of the embodiments of the prior art mentioned above. Next, the invention proposes to solve a problem relating to the management of the assembly and disassembly force that a user must exert, this force having to be neither too strong nor too weak to ensure a stable and sufficiently strong assembly. Another problem relates to maintaining the two main parts of the casing in a precise assembly position, in particular along the axial direction of the sealed case, and without radial play and axial play.

[0006] To this end, the present invention relates to a watch assembly comprising a waterproof case in which are housed a watch movement and an analog or digital time display device, an outer trim part configured to be able to surround the sealed casing, and an elastic element forming a removable assembly system of the outer trim part with the sealed casing. The removable assembly system allows axial mounting of the sealed casing in the outer trim part and axial removal of the sealed casing from the outer trim part by exerting axial pressure on this sealed casing, so to overcome an elastic force generated by an elastic deformation of the elastic element during such axial mounting, respectively such axial withdrawal. According to the invention, the elastic element is an elastomer seal configured to be able to be arranged in a groove machined in a side wall of the sealed casing or in an inner wall of the outer trim part and to present, once put in place in the groove, a projecting part out of this groove. Then, the elastomer seal is configured to be able to undergo, during assembly or disassembly of the outer trim part and the sealed casing, an elastic deformation allowing the sealed casing to be inserted by force into the outer trim part so that the protruding part comes to be placed at least partly in a hollow or behind a recess presented by the inner wall of the outer trim part or the side wall of the sealed casing depending on whether the groove is respectively machined in said side wall or in said inner wall.

[0007]According to an advantageous embodiment, the elastomeric seal has a cross section of which a first part, located in said groove, is oblong and defines a longitudinal axis which is parallel to a central axis of the sealed casing, said projecting part forming a second part of the cross section which has, in a middle zone of the groove, a convex external curvature and whose extreme point is the point of the external profile of the cross section furthest from said longitudinal axis.

According to a preferred variant, the groove has at its bottom a surface defining a median channel bordered by two shoulders against which the first part of the elastomeric seal rests at least when the two main parts, namely the sealed housing and the part of cladding, are assembled. This preferred variant is particularly useful for making it possible to manage an axial force that a user must apply to assemble and disassemble the two main parts. Indeed, the median channel allows, in addition to a certain compression of the elastomeric seal, a transverse bending of this elastomeric seal which can bend, in any transverse plane, by penetrating into the median channel during the passage of a zone projection of relatively high pressure which is located axially upstream of said hollow or said recess.

Brief description of figures

The invention will be described below in more detail using the accompanying drawings, given by way of non-limiting examples, in which: FIG. 1 is a perspective view of one embodiment of the timepiece assembly according to the invention, with the sealed case and the outer casing part disassembled; Figure 2 is a top view of the watch assembly of Figure 1 where the waterproof case and the outer casing part are assembled; Figure 3 is a partial cross section of the watch assembly of Figure 2 along section line III-III; Figures 4A, 4B and 4C are localized sections showing the configurations of the groove for receiving the elastomeric seal and of this unconstrained and constrained elastomeric seal; Figures 5A and 5B show another, less advantageous, embodiment of the elastomeric seal and receiving groove; And Figures 6 and 7 are two partial cross sections of the watch assembly of Figure 2 respectively along section lines VI-VI and VII-VII.

Detailed description of the invention

With reference to Figures 1 to 4C, 6 and 7, there will be described below a preferred embodiment of a watch assembly 2 according to the invention.

[0011] The watch assembly 2 comprises a waterproof case 4 in which are housed a watch movement 28 and an analog display device 12, an outer covering part 6 configured to be able to surround the waterproof case, and an elastic element 8 which forms a removable assembly system of the outer trim part with the waterproof casing. The waterproof case 4 comprises a caseband 10 defining an internal caseband in the watch resulting from the assembly of the two distinct main parts that are this waterproof case and the outer trim part. The sealed case further comprises a glass 20 mounted on the inner caseband 10 and covering the analog display, and it defines a central axis 11 perpendicular to the glass.

[0012] A crown 14 is connected to the watch movement via a control rod and is thus secured to the waterproof case. The outer covering part 6 forms an outer middle part 16, an outer bezel 18 surmounting the outer middle part and a device for fixing a bracelet to the outer middle part, this fixing device comprising four lugs 22. It will be noted that the expressions middle part external' and 'external bezel' are used by analogy with the terms 'middle' and 'bezel' well known in watchmaking, because their respective visual aspects correspond to these two terms even though the external bezel does not carry glass and no back is not fixed to the outer middle.

[0013] The removable assembly system is provided to allow axial mounting, in the direction of the central axis 11, of the sealed casing 4 in the outer trim part 6 and also an axial removal of this sealed casing from the exterior trim part by exerting axial pressure on this sealed casing, so as to overcome an elastic force generated by an elastic deformation of the elastic element during such axial mounting, respectively such withdrawal axial. This elastic element 8 is an elastomer seal configured to be able to be arranged in a groove 30 machined in the side wall 32 of the sealed casing, or alternatively in an inner wall 36 of the outer trim part (first variant not shown) and to present , once placed in the groove, a projecting part 44 out of this groove. In general, the elastomer seal is configured to be able to undergo, during assembly or disassembly of the outer trim part 6 and the sealed casing 4, an elastic deformation allowing the sealed casing to be inserted by force into the part external covering so that the protruding part finally comes to be placed at least partly in an annular hollow 40 or alternatively above a shoulder / recess, for example defined by an internal protruding zone, (second variant not shown) presented by the inner wall 36 of the outer trim part or the side wall 32 of the sealed casing depending on whether the groove 30 is respectively machined in the side wall or in the inner wall (case of the first variant). In the second variant, a cylindrical zone above the shoulder has a height such that the protruding part 44, once the sealed case is assembled to the outer covering part, is not pressed on the top. In particular in the case where only a shoulder is provided to retain the elastomer seal below (by exerting pressure axially on a lower zone of the projecting part 44), it is then provided that the sealed casing has a surface which comes to bear axially against a corresponding surface of the outer trim part in the assembly position, in particular an inner surface of the outer bezel, so as to ensure precise axial positioning of the sealed case in the outer trim part by machining this last. In all cases, it is advantageous for the sealed casing 10 to bear against an axial abutment defined by the external covering part when these two parts are assembled, in particular because a certain axial force is generally exerted on the bottom of the waterproof case when the watch assembly, forming a wristwatch, is worn on the wrist of a user.

In the specific variant shown, the inner wall 36 comprises an internal protruding zone 38 of high stress for the elastomeric seal during assembly or disassembly of the outer trim part on the sealed casing, this internal protruding zone being located at the - below the annular hollow 40 in which it is intended to finally house the projecting part 44 of the elastomer seal. This protruding part and the annular hollow 40 are dimensioned so that the elastomeric seal remains a little constrained, that is to say a little elastically deformed, when the protruding part is at least partly, preferably for the most part located in the annular hollow and centered relative to the latter, that is to say in its final assembly position before locking the assembled timepiece assembly (which will be explained later). Thus, the elastomer seal 8 ensures a relatively stable assembly, without clearance, of the sealed case and the external covering part already before locking of the assembled watch assembly, and therefore a relatively precise axial positioning of the sealed case in the part. exterior trim. In particular, as shown, the projecting part 44 is formed by a central annular bead.

In the preferred embodiment shown in the figures, the elastomeric seal 8 has a cross section of which a first part 46, located in the groove 30, is oblong and defines a longitudinal axis 47 which is parallel to the central axis 11 of the sealed casing 4 before mounting the outer trim part on the sealed casing. The projecting part 44 forms a second part 48 of the cross section which is located outside the groove 30 and which has, in a middle zone of this groove, a convex external curvature whose extreme point 50 is the point of the external profile of the cross-section farthest from said longitudinal axis. Next, the groove 30 has at its bottom a transverse profile defining a median channel 34 bordered by two shoulders 55 and 56 against which two zones 53 and 54 of the first part 46 of the elastomer seal bear. Preferably, the inside diameter of the unstressed elastomer seal is provided smaller than the diameter of the groove 30 at the level of the two support zones 55, 56. In an advantageous variant shown in FIGS. 4A to 4C, the elastomer seal has a rounded profile at both ends of its cross section. This makes it possible to increase the manufacturing tolerances of the removable assembly system while ensuring that the elastomer seal is correctly positioned in the groove, with no axial play. To this end, provision is made for the elastomer seal to have a height between the two vertices of the two rounded ends which is slightly greater than the height of the groove 30. A certain axial deformation force is therefore exerted on the elastomer seal when it is introduced into the groove

For example, the support zones 55, 56 each have a height between 0.2 and 0.4 mm and the median channel 34 has a height between 0.8 and 1.2 mm (height means the axial dimension). By varying the height of the median channel, the stiffness of the elastomer seal can be adjusted. The elastomeric seal advantageously has a high capacity for elastic deformation. It may consist of a flexible elastomer of the NBR or TPU type. Preferably, the elastic modulus of the elastomer gasket is between 5 and 20 MPa. The configuration of the elastomer seal 8 and its constitution make it possible to ensure good resistance of the seal to deformation. According to a preferred variant, the dimension of the median channel 34 along said central axis 11, namely the height of this median channel, is substantially equal to the dimension of the central bead 44.

The configuration of the elastomer seal 8, its construction and the profile of the groove 30 have many advantages. Firstly, they make it possible to control the force of deformation during assembly and disassembly of the two main parts of the casing (sealed casing and exterior casing part). Thus, it is possible in particular to select the deformation force during this assembly and this disassembly so that the force to be applied to the waterproof case and, in the opposite direction, to the external display part is included in a certain range of given values. , in particular between 50 and 150 Newton. Then, as already mentioned, the median channel 34 makes it possible to better adjust the force of deformation of the elastomer seal during assembly and also during disassembly of the two main parts, without having to reduce the manufacturing tolerances. This median channel allows less crushing of the bead 44 during the passage of the protruding zone 38, because in addition to an elastic compression the joint also undergoes an elastic bending. There are therefore two main elastic deformation modes. The elastic bending allows a greater radial displacement of the bead 44 while limiting its compression and that of the material of the first part 46 located behind this bead, and therefore makes it possible to have a lower maximum deformation force during the passage of the protruding zone 38 of the outer trim piece than that which would be necessary in the absence of such a channel. It follows from this characteristic that the elastomeric seal can retain a certain stiffness and therefore good resistance for a relatively small given maximum deformation force, while making it possible to provide a fairly deep annular hollow 40, which is filled by the bead when the latter finally takes place in this annular hollow.

Finally, it will be noted that the elastomer seal 8 has an aesthetic advantage because the groove 30 is almost filled by this elastomer seal. It is possible to provide a depth of the groove 30 so that only the bead 44 substantially emerges from the general cylindrical shape of the side wall 32.

In Figures 5A and 5B is shown another embodiment of the removable assembly system of the two main parts forming the watch assembly according to the invention. This embodiment does not have all the advantages of the embodiment described above, although it can also be functional with smaller tolerances and a little increased assembly and disassembly force. The elastomer seal 8A has a cross section which is circular and it is inserted for the most part into a groove 30A of the internal middle part 10A which has a rectangular cross section. The depth of the groove 30A is provided so that the O-ring seal 8A (O-Ring seal) has a protruding part out of the side wall of the inner middle part 10A. When assembling and disassembling the two main parts, the elastomeric seal essentially undergoes here a crushing, however with a small displacement of material in the inner corners of the rectangular cross section. The profile of the inner wall 36 of the outer caseband 16 is substantially identical to that of the previous embodiment. However, the protruding zone 38 is provided a little lower.

[0020] According to an advantageous embodiment, the watch assembly according to the invention further comprises a locking device for holding the sealed case 4 and the outer covering part 6 together in the event that an untimely axial pressure is exerted down on the waterproof case 10 (that is to say on the glass 20). In general, this locking device is arranged so as to be able, in a first configuration, to ensure the maintenance of the sealed box in the outer trim part. Then, the locking device is arranged to allow a user to actuate it manually between the first configuration and a second configuration in which the waterproof casing is released to allow its removal from the outer trim piece by this user.

As shown in Figure 6, the locking device comprises a control crown 14 provided to control functions of the watch movement 28 and also to allow, if necessary, the winding of a barrel. This control crown 14 is integral with the sealed case 4 and it has a thread 62 allowing it to be screwed onto the sealed case, which for this purpose also has a corresponding thread 64. The crown is arranged so that, when it is screwed towards the sealed case, an inner surface 66 of this crown presses against a side surface 68 of the outer trim piece. This blocks the axial position, on the side of the control crown, of the exterior trim part 6. In an advantageous variant, it is provided that the control crown does not press against a surface of the exterior caseband, but that an internal part of this control crown is housed in a recess of the outer caseband when the control crown is in its retracted axial position, this recess having a shape limiting possible axial movement for this control crown (as is also already the case in the variant shown). It will be noted that this advantageous variant is particularly suitable for an embodiment in which the control crown is not screwed down. The advantageous variant makes it possible to prevent the control crown 14 from decentering the waterproof case 10 when it is retracted or screwed down. Its retracted or screwed position serves, in the locking device, to prevent disassembly of the sealed casing and of the outer covering part by limiting a possible relative axial movement between these two parts.

As shown in Figure 7, the locking device advantageously further comprises a locking element 26 which is mounted on the outer trim part 6 and arranged so as to be able to be actuated by a user between a locking position , in which an internal part 72 is inserted into a groove 74 machined in the side wall 36 of the sealed casing 4, and an unlocking position where the internal part 72 is located outside the groove and sufficiently far from the side wall 36 of the sealed casing to allow the axial withdrawal of this sealed casing from the outer trim part. In the variant shown, the locking element 26 is formed by a locking ring which has an internal thread 78 allowing this ring to be screwed onto a threaded tube 76 which is fixed to the outer trim part 6. It will be noted that the groove 74 preferably has a frustoconical transverse profile and the internal element 72 is formed by a screw having such a frustoconical head. Thus, it is possible to position the outer covering part 6 very precisely axially relative to the sealed casing 4. It will be noted that, in an advantageous variant, it is provided that the internal element 72, in its locking position, does not press against the sealed casing 10, but that it limits a relative axial displacement between this sealed casing and the outer trim part 6.

[0023] In a variant where it is provided that the internal element 72 bears against the sealed casing 10 in the locking position and that the control ring 14 also bears against this sealed casing in its retracted position, it is it is therefore advantageous to put the crown 26 in its locking position before retracting the control crown 14 in order to be able to precisely center the waterproof case in the outer trim part. By finely adjusting the radial position of the head of the internal element 72, it is in fact possible to perfectly center the waterproof case in the outer trim part, in particular so that the glass 20 is well centered in the outer bezel 18.

Finally, in an alternative not shown, the locking element is formed by a bistable plunger having a first stable position corresponding to the unlocking position and a second stable position corresponding to the locking position.

Claims (10)

1. Watch assembly (2) comprising: ¿ a waterproof case (4) in which are housed a watch movement and a time display device, ¿ an outer covering part (6) configured to be able to surround the waterproof casing, and ¿ an elastic element (8, 8A) forming a removable assembly system of the outer trim part with the waterproof casing; the removable assembly system being provided to allow axial mounting of the sealed casing in the outer trim part and axial removal of the sealed casing from the outer trim part by exerting axial pressure on this sealed casing , so as to overcome an elastic force generated by an elastic deformation of said elastic element during such axial mounting, respectively such axial withdrawal; characterized in that the elastic element is an elastomeric seal (8, 8A) configured to be able to be arranged in a groove (30, 30A) machined in a side wall (32) of the sealed casing or in an interior wall (36) of the exterior trim part and to present, once placed in the groove, a protruding part (44) outside this groove; and in that the elastomer seal (8, 8A) is configured to be able to undergo, during assembly or disassembly of the outer trim part and the sealed casing, an elastic deformation allowing the sealed box in the outer trim part so that the projecting part comes to be placed at least partly in a hollow (40) or behind a shoulder presented by the inner wall (36) of the outer trim part or the wall side (32) of the sealed casing depending on whether the groove is respectively machined in said side wall or in said inner wall. 2. Watch assembly according to claim 1, characterized in that the elastomeric seal (8) has a cross section of which a first part (46), located in said groove (30), is oblong with a rounded profile at its two ends, the first part defining a longitudinal axis (47) which is parallel to a central axis (11) of the sealed casing, the said projecting part (44) forming a second part (48) of the said cross section which presents, in a median zone of the groove, a convex external curvature and whose extreme point (50) is the point of the external profile of the cross section farthest from said longitudinal axis. 3. Watch assembly according to claim 2, characterized in that the groove (30) has at its bottom a surface defining a median channel (34) bordered by two shoulders (55, 56) against which two zones (53, 54) bear. of the first part (46) of the elastomer seal at least when the sealed casing (4) and the outer covering part (6) are assembled. 4. Watch assembly according to claim 3, characterized in that the dimension of the median channel (34) along said central axis is substantially equal to the dimension of a central bead (44) forming the projecting part and defining the end point of said cross section. 5. Watch assembly according to claim 4, characterized in that said bead (44) is mostly located in said hollow (40) when the sealed case and the outer covering part are assembled. 6. Watch assembly according to any one of the preceding claims, characterized in that it further comprises a locking device for holding the sealed case (4) and the outer covering part (6) together, this locking device being arranged so as to be able, in a first configuration, to limit an axial movement of the sealed casing in the outer trim part once assembled; and in that the locking device is arranged to allow a user to actuate it manually between the first configuration and a second configuration in which the sealed casing is released to allow its removal from the outer trim piece by this user. 7. Watch assembly according to claim 6, characterized in that the locking device comprises a control crown (14) for said watch movement (28) and integral with the sealed case (4), this control crown having a screw pitch (62) allowing it to be screwed onto the waterproof case. 8. Timepiece assembly according to claim 6 or 7, characterized in that the locking device comprises a locking element (26) mounted on the outer covering part (6) and arranged so as to be able to be actuated by a user between a locking position, in which an internal part (72) is inserted into a groove (74) machined in the side wall (36) of the sealed case, and an unlocking position in which said internal part is located outside the groove and far enough from the side wall to allow said axial withdrawal of the sealed casing (4) from the outer trim part. 9. Timepiece assembly according to claim 8, characterized in that the locking element (26) is formed by a locking crown which is mounted screwed onto a threaded tube which is fixed to the outer trim part. 10. Timepiece assembly according to claim 8, characterized in that the locking element is formed by a bistable pusher having a first stable position corresponding to the unlocking position and a second stable position corresponding to the locking position.