Watch case, wristwatch and kit for assembling a wristwatch comprising same

Abstract

The invention relates to a watch case (2) for a wristwatch (1) comprising a case body (6); at least one support bar (7a, 7b) for the case body (6), the support bar (7a, 7b) extending beyond the space occupied by the case body (6); means (8) for the removable attachment of a strap (4) to the support bar (7a, 7b). The watch case (2) further comprises a device (13) for attaching the support bar(s) to the case body (6), the removable attachment means (8) being formed when said support bar (7b) is attached to the case body (6); and said fixing member (13) is provided with means (24) for detaching said stretcher (7b) from the frame (6), configured to allow tool-free release of the stretcher (7b) from the frame (6), said stretcher (7b) being removably fixed to the frame (6).

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to a watch case for a wristwatch.

[0002] The invention also relates to a wristwatch comprising the watch case and a strap attached to the watch case.

[0003] The invention further relates to an assembly kit for the wristwatch, comprising the wristwatch and several wristbands. STATE OF THE ART

[0004] In the field of mechanical or electromechanical wristwatches, it is known to provide, for a watch case fitted with a caseband, at least one caseband support stretcher.

[0005] Such a watch case is for example described in patent application EP 0 386 621 A1. In this watch case, two caseband support stretchers are arranged on either side of the caseband. The two stretchers extend beyond the space occupied by the caseband to serve as means of attaching a bracelet. To do this, two spring bars are fixed by their pivots in housings, generally formed of blind holes, made in opposite faces of the ends of the stretchers, the bars each being inserted into an eyelet provided at one end of each strand of the bracelet. The two stretchers are permanently fixed to the caseband, for example via screws. However, a disadvantage of the proposed watch case is that it does not allow the bracelet to be changed without tools.In fact, to change the strap, it is necessary to act on the pivots of the spring bars using a suitable tool, in order to retract them and release them from their housings to separate the strap from the watch case.

[0006] Patent application CH 513453 describes a wristwatch having a frame, a bracelet whose two ends are attached to the frame, and a watch case held between the elements of the frame. More specifically, the elements of the frame consist of two stretchers arranged on either side of the middle of the watch case, and two members for attaching the stretchers to the bracelet. According to a particular embodiment of this wristwatch, the two members for attaching the stretchers to the bracelet consist of two screws which connect the stretchers at their ends, and which each have at one end a knurled head which projects outside the stretchers. Each screw is inserted inside an eyelet made in one end of a strand of the bracelet, in order to ensure the bracelet is attached to the frame.By unscrewing the screws via their knurled heads, a user can separate all the elements of the frame, and thus release the bracelet from the watch case. This allows the bracelet or watch case to be changed without tools. However, such disassembly requires action on each of the screws, i.e. two disassembly operations in total. This complicates the bracelet changing operation. In addition, once the screws are removed, all the elements of the wristwatch are separated. This constitutes an additional disadvantage due to the risk of falling and breaking the elements. The disassembly operation is thus made cumbersome and impractical.

[0007] Also known from document CH 124 791 is a watch holder with a bracelet made of two or more pieces, provided with members fixed on one or more of these pieces and forming, when assembled, clasps to which the strap of the bracelet can be attached.

[0008] Document US2 559 238 describes fastening means for securing a bracelet to a watch case. These means comprise a groove provided at the periphery of the case and extending more than 180°; an arcuate spring element with re-entrant end portions; and recesses at the ends of said groove for receiving the end portions, the bracelet strands being threaded over these spring elements.

[0009] Document JP S63 99292 U discloses a wristwatch in which two stretchers are connected by lateral screws. SUMMARY OF THE INVENTION

[0010] The invention therefore aims to provide a watch case for a wristwatch which allows the strap to be changed without tools, in an easy and non-restrictive manner, and which overcomes the aforementioned drawbacks of the state of the art.

[0011] To this end, the invention relates to a watch case for a wristwatch, which comprises the features mentioned in independent claim 1.

[0012] Particular shapes of the watch case are defined in dependent claims 2 to 10

[0013] An advantage of such a watch case according to the invention lies in the fact that a support stretcher for the caseband is removably attached directly to the latter, and that the means for removably attaching the bracelet to the stretcher are formed when the stretcher is attached to the caseband.

[0014] Thanks to the means for detaching the stretcher, fitted to a member for attaching the stretcher to the caseband, a user can easily change the strap without tools. Indeed, since the removable attachment means for attaching the strap to the stretcher are formed when the stretcher is attached to the caseband, the strap detaches conversely very easily from the stretcher when the latter is detached from the caseband. This single disassembly operation is extremely simple for the user, who can then change the strap by detaching the initial strap from the stretcher(s) and replacing it with a new strap. The user can then regularly change the strap of his wristwatch, for example for aesthetic reasons or convenience.

[0015] Advantageously, the means for removable attachment of a bracelet to the stretcher comprise means for retaining the bracelet, capable of being inserted into an eyelet or a similar device provided in one end of a strand of the bracelet. This makes it easier to change the bracelet once the removable stretcher has been detached, by allowing easy release of the bracelet from the stretcher.

[0016] According to a particular embodiment of the invention, the watch case comprises two caseband support stretchers, arranged on either side of the caseband; one of the two stretchers forming the stretcher removably attached to the caseband, the other stretcher being secured, for example, permanently to the caseband.

[0017] Advantageously, each stretcher is provided with two L-shaped end portions, each L-shaped end portion of each stretcher forming one of said retaining means and comprising an axis capable of being inserted into an end strand of the bracelet. This makes it possible to further facilitate the bracelet changing operation once the removable stretcher has been detached, by allowing easy release of the bracelet by simply sliding along the end axes of the stretchers.

[0018] Advantageously, each stretcher came in one piece with its L-shaped end portions. This makes it easier to machine the stretchers and reduces their manufacturing cost.

[0019] Advantageously, the stretcher is attached to one side of the caseband. This reduces the cost of machining the watch case.

[0020] For this purpose, the invention also relates to a wristwatch comprising the watch case described above, which comprises the features mentioned in claim 8.

[0021] A particular form of the wristwatch is defined in claim 9.

[0022] For this purpose, the invention also relates to a kit for assembling a wristwatch, comprising the wristwatch described above, and which comprises the features mentioned in claim 10. BRIEF DESCRIPTION OF THE FIGURES

[0023] The aims, advantages and characteristics of the watch case, as well as of the wristwatch and the assembly kit comprising it, will appear better in the following description on the basis of at least one non-limiting embodiment illustrated by the drawings in which: there figure 1 is a top view of a wristwatch which comprises a watch case according to the invention; the Figures 2a and 2b are respectively a sectional view of a part of the watch case of the figure 1 , taken according to a section plane II-II; respectively III-III of the figure 1 ; and the Figures 3 and 4 are exploded perspective views of the wristwatch of the figure 1 . DETAILED DESCRIPTION OF THE INVENTION

[0024] There figure 1represents a wristwatch 1, which comprises a watch case 2 and a strap 4 removably attached to the watch case 2. The wristwatch 1 may for example belong to a kit (not shown) further comprising one or more additional strap(s). Such additional straps constitute interchangeable straps for the wristwatch 1, which can be removably attached to the watch case 2. By way of non-limiting example, the strap 4 and the additional straps may for example be made of articulated metal links, a plastic material, or a flexible material such as leather.

[0025] In the remainder of the description, without limitation, elements will be described as interior or exterior depending on their orientation relative to the watch case 2.

[0026] The watch case 2 comprises a case middle 6 and at least one stretcher 7a, 7b for supporting the case middle 6. In the particular embodiment illustrated in the figures 1 to 4 , the watch case 2 comprises two support stretchers 7a, 7b. The watch case 2 further comprises means 8 for removable attachment of the bracelet 4 to the stretchers 7a, 7b, and a member 13 for removable attachment of one of the stretchers 7a, 7b to the caseband 6.

[0027] The watch case 2 contains a movement (not shown) of usual construction, for example a mechanical movement of circular shape; as well as a dial 9 above which display means formed of hands 10 move. The movement comprises a winding crown 11 which extends outside the watch case 2, through an orifice provided in the caseband 6.

[0028] As illustrated in the figures, the caseband 6 is annular in shape and is closed by a back 12 in the lower part, by a crystal 18 whose peripheral edge rests on an upper annular rim 16. The crystal 18 is for example a sapphire crystal. In the watch case 2 taken as an example in figures 1 to 4 , the configuration of the watch case is substantially circular. However, the invention is in no way limited to such a configuration of the watch case, nor to the other arrangements described above for the caseband 6.

[0029] Each stretcher 7a, 7b is preferably attached to a side of the middle 6. To do this, the middle 6 comprises, for example, at least one groove 20a, 20b for receiving a stretcher 7a, 7b, hollowed out in one of its sides. In the particular embodiment shown in figures 1 to 4 , the middle 6 comprises two grooves 20a, 20b. As illustrated in the figures 1 And 2a and 2b, the depth of each groove 20a, 20b is such that the corresponding stretcher 7a, 7b is housed flush with the case in the groove 20a, 20b. This makes it possible to reduce the machining costs of the watch, while improving the aesthetic appearance of the latter.

[0030] The stretchers 7a, 7b are arranged on either side of the middle 6 and are oriented in the direction of a longitudinal direction corresponding generally to the direction of extension of the bracelet 4. The longitudinal direction corresponds substantially to the 6 o'clock - 12 o'clock direction of the watch case 2 when the bracelet 4 is attached to the watch case 2. As illustrated in the figure 1 , the stretchers 7a, 7b protrude at 6 o'clock and 12 o'clock from the middle 6 so that they allow the bracelet 4 to be attached to the watch case 2, as will be described in more detail later.

[0031] A first stretcher 7a among the two stretchers is secured to the middle 6 and is not intended to be detached from the middle by the user as is the case for the second stretcher 7b for reasons which will appear below. To do this, the first stretcher 7a has a central portion pierced in its center with a passage hole for the winding crown 11. The hole (not shown) is aligned with the orifice of the middle 6, so that the winding crown 11 extends through the middle 6 and the first stretcher 7a. The latter further comprises at each of the ends of its part - arched in the example illustrated - coming to be housed in the groove 20a formed in the side of the middle, a threaded hole 7c extending in a direction perpendicular to the plane of the dial 9.The holes each receive a fixing screw 7d which passes through a hole 6a opening into the groove 20a of the case to secure the stretcher 7a to a right side of the case 6 (. Figure 2b ). The right flank is defined as the flank located on the side of the right half of dial 9, considered in relation to the 6 o'clock - 12 o'clock axis of watch case 2.

[0032] A second stretcher 7b is removably attached to the middle 6 via the fixing member 13. The fixing member 13 is provided with means 24 for detaching the second stretcher 7b from the middle 6. The detaching means 24 are configured to allow tool-free release of the second stretcher 7b from the middle 6, as will be detailed later. In the particular embodiment of the figures 1 to 4, the fixing member 13 is formed of a crown. The crown 13 comprises a head 26 extended by a fixing rod 28. The head 26 of the crown projects outside the watch case 2 and in this example forms the detaching means 24. The second stretcher 7b has a central portion 22b pierced in its center with a light 30 for the passage of the crown 13. Such a position of the light 30 in the center of the central portion 22b of the second stretcher 7b is however in no way limiting within the scope of the present invention.

[0033] As illustrated in the Figure 2a, the light 30 is aligned with an opening 32 provided on a left flank of the caseband 6. The opening 32 receives the fixing rod 28 of the crown 13, allowing firm fixing of the second stretcher 7b against the left flank of the caseband 6 when the crown 13 is engaged in the caseband 6, through the second stretcher 7b. In the particular embodiment shown in Figure 2a , the fixing rod 28 is a screw and the opening 32 is a threaded opening. In a variant not shown, the fixing rod 28 is a bayonet and the opening 32 is capable of cooperating with the bayonet to allow the fixing of the second stretcher 7b on the middle 6.

[0034] The central portion of each stretcher 7a, 7b is of a shape complementary to that of one of the grooves 20a, 20b of the caseband 6, so as to be received in the groove 20a, 20b. In the watch case 2 taken as an example in figures 1 to 4, the central portions of the stretchers 7a, 7b are of arcuate shape. However, the invention is in no way limited to such a shape for the central portions of the stretchers.

[0035] Preferably, the second stretcher 7b comprises at least one element 34 for guiding and positioning the stretcher on the middle 6, visible in Figures 3 and 4 . In the particular embodiment shown in figures 1 to 4 , the second stretcher 7b comprises two guide and positioning elements 34. Each guide and positioning element 34 is for example formed of a stud projecting from an inner face of the central portion 22b of the stretcher. The middle 6 comprises on its left side, for example in the groove 20b formed on this side, two orifices 36 for receiving the elements 34. In the particular embodiment shown in figures 1 to 4, each element 34 is arranged at one end of the central portion 22b of the second stretcher 7b, and each receiving orifice 36 is arranged at a corresponding position on the middle 6. However, this location of the elements 34 and the orifices 36, as well as their number, is in no way limiting within the scope of the present invention.

[0036] Preferably, the means 8 for removable attachment of the bracelet 4 to the stretchers 7a, 7b comprise means 42 for retaining the bracelet 4, inserted into eyelets 40a provided in the ends 40 of the bracelet 4 intended to be fixed to the case. In the example illustrated, the bracelet is a flexible bracelet whose eyelets 40a conventionally define a through passage extending from one lateral edge to the other of the bracelet strand, but it goes without saying that according to a variant the passage defining the eyelets 40a of the bracelet is not through, since its length is capable of receiving the bracelet retaining means.

[0037] In the particular embodiment of the figures 1 to 4 , each stretcher 7a, 7b is provided with two “L” shaped end portions. According to this exemplary embodiment, the retaining means 42 are thus formed from the “L” shaped end portions. Preferably, each stretcher 7a, 7b comes in one piece with its two “L” shaped end portions 42.

[0038] Each “L”-shaped end portion 42 comprises an axis 44 inserted into the eyelet 40a provided in the ends 40 of the bracelet 4. Each axis 44 is substantially parallel to the 3 o'clock - 9 o'clock axis of the watch case 2 when the corresponding stretcher 7a, 7b is fixed to the middle 6. In this way, each strand 40 of the bracelet 4 receives in its eyelet 40a two opposite axes 44 each belonging to one of the stretchers 7a, 7b. This configuration of the axes 44 in the strands 40 thus provides a removable attachment 8 of the bracelet 4 to the stretchers 7a, 7b, the attachment 8 being formed when the second stretcher 7b is fixed to the middle 6.

[0039] As illustrated in the figure 1, the opposite axes 44 inside the same eyelet 40a of a strand of the bracelet 4 have a length such that a small space 46 is provided between the free ends of the axes 44 when the second stretcher 7b is fixed to the middle 6 while maintaining a penetration length of the axes sufficient to ensure a reliable hold of the bracelet 4 on the retaining means when the bracelet 4 is subjected in particular to a tensile force along the longitudinal axis of the bracelet. It will be noted in this regard that in the case where the material of the bracelet is flexible, the eyelets 40a of the bracelet will be advantageously equipped with rigid reinforcing tubes.

[0040] Preferably, the external surface of the pins 44 is treated so as to obtain a coefficient of friction such that it allows a predetermined clearance of the pins 44 in the eyelets 40a of the strands of the bracelet 4. Such a treatment is for example obtained via the deposition of a coating layer on the pins 44, such a coating layer being able for example to be a layer of polytetrafluoroethylene (PTFE). This makes it possible to further facilitate the operation of mounting and dismounting the bracelet 4.

[0041] The strap changing operation in the wristwatch 1 comprising the watch case 2 according to the invention will now be described with reference to Figures 3 and 4 .

[0042] When a user wishes to detach the strap 4 from the watch case 2, for example to change the strap, he begins by actuating the means 24 for detaching the second stretcher 7b. In particular, as illustrated in the figure 3, the user first unscrews the head 26 of the crown 13, which allows the second stretcher 7b to be disengaged from the groove 20b in the direction of the arrow F1. This operation allows the second stretcher 7b to be separated from the middle 6. In doing so, the means 8 for removable attachment of the bracelet 4 to the stretchers 7a, 7b are partially undone, by sliding the end pins 44 of the second stretcher 7b out of the strands 40 of the bracelet 4.

[0043] In a second step, as illustrated in the figure 4 , the user simply has to slide the bracelet 4 along the end axes 44 of the first stretcher 7a in the direction of the arrows F2 to allow easy extraction of the bracelet 4. The bracelet 4 is then completely separated from the rest of the watch.

[0044] The user can then advantageously replace the bracelet 4 with a new bracelet, then attach the latter to the stretchers 7a, 7b by reversing the sequence of operations described above.

[0045] The preceding description of the watch case according to the invention was made with reference to two caseband support stretchers. However, this particular number of stretchers is in no way limiting within the scope of the present invention as defined by the claims. In particular, according to an alternative embodiment not shown, the watch case may comprise only one caseband support stretcher, which then forms the removable stretcher.

Claims

1. A watch case (2) for a wristwatch (1) comprising: - a middle (6); - at least one lug (7a, 7b) for supporting the middle (6), the lug (7a, 7b) extending beyond the space occupied by the middle (6); - means (8) for detachably attaching a wristlet (4) to the lug (7a, 7b); the watch case (2) further comprising an organ (13) for attaching the or one of the lugs to the middle (6), the detachable attachment means (8) being formed when said lug (7b) is attached to the middle (6); in which said attachment organ (13) is provided with means (24) for detaching said lug (7b) from the middle (6), configured to enable tool-free release of the lug (7b) from the middle (6), said lug (7b) being detachably attached to the middle (6), in which the means (8) for detachably attaching a wristlet (4) to the lug (7a, 7b) comprise means (42) for holding the wristlet (4) that can be inserted into end sections (40) of the wristlet (4) and in which the lug (7a, 7b) is attached to a flank on the middle (6); said case further comprising a crown comprising a head (26) extended by an attachment arbor (28), the crown forming the attachment organ (13), the head (26) of the crown projecting outside the watch case (2) and forming the means for disengaging (24) the lug (7b) from the middle (6) and in which the attachment arbor (28) is a screw, the detachably attached lug (7b) is provided with a through-hole (30) for the screw and the middle (6) is provided with a threaded opening (32) suitable for receiving the screw or in which the attachment arbor (28) is a bayonet, the detachably attached lug (7b) is provided with a through-hole for the bayonet and the middle (6) is provided with an opening suitable for receiving the bayonet.

2. The watch case (2) according to claim 1, characterised in that the middle (6) further comprises at least one groove (20a, 20b) for receiving a lug, the groove (20a, 20b) being recessed in a flank of the middle (6), having a complementary shape to that of a central portion (22b) of the lug (7a, 7b) and receiving said central portion (22b) of the lug (7a, 7b), the groove (20a, 20b) having a depth such that the lug (7a, 7b) is embedded in the groove (20a, 20b) flush with the case.

3. The watch case (2) according to any of the preceding claims, characterised in that the watch case (2) is substantially circular in shape, and in that the lug (7a, 7b) comprises an arched central portion (22b).

4. The watch case (2) according to any of the preceding claims, characterised in that the detachably attached lug (7b) further comprises at least one element (34) for guiding and positioning the lug (7b) on the middle (6), and in that the middle (6) further comprises at least one receiving orifice (36) arranged to engage with said guiding and positioning element (34).

5. The watch case (2) according to any of the preceding claims, characterised in that it comprises two lugs (7a, 7b) for supporting the middle (6), arranged on either side of the middle (6), one of the two lugs forming the lug (7b) detachably attached to the middle (6), the other lug (7a) being permanently attached to the middle (6).

6. The watch case (2) according to claims 1 and 5 taken together, characterised in that each lug (7a, 7b) is fitted with two L-shaped end portions (42), each L-shaped end portion (42) of each lug (7a, 7b) forming one of said holding means (42) and comprising a pin (44) designed to be inserted into an end section (40) of the wristlet (4).

7. The watch case (2) according to claim 6, characterised in that each lug (7a, 7b) is made in one piece with its L-shaped end portions (42).

8. A wristwatch (1) comprising a watch case (2) and a wristlet (4) attached to the watch case (2), characterised in that the watch case (2) is consistent with any of the preceding claims, the lug (7a, 7b) being oriented in the longitudinal direction of the wristlet (4), the wristlet (4) being detachably attached to the lug (7a, 7b).

9. The wristwatch (1) according to claim 8 when the watch case (2) is according to claim 6, characterised in that the wristlet (4) is fitted with two end sections (40), the pin (44) of each L-shaped end portion (42) of each lug (7a, 7b) being inserted into one of the end sections (40) of the wristlet (4), said pin (44) being substantially parallel to a three o'clock - nine o'clock axis of the watch case (2).

10. A wristwatch assembly kit comprising a wristwatch (1) and at least one wristlet (4), characterised in that the wristwatch (1) is consistent with claim 8 or 9.

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