Adjustable bracelet clasp

Abstract

The invention relates to a clasp (100) for a watch strap comprising a cap (3) connected on one side to a first strap strand and on the other side to a second strap strand, connecting means being interposed between the second strap strand and the cap (3) of the clasp (1), these connecting means comprising an end link (10) sliding along a longitudinal direction of the clasp (1) between a frame (8) integral with the cap and the cap (3), from a first position in which the end link (10) is at least partially engaged in the cap (3) of the clasp (1), to a second position in which the end link (10) is disengaged from the cap (3) of the clasp (1), the clasp comprising a pressure-operated control member (6) for moving a toothed element (7) integral with the control member (6) from a first position in which the toothed element (7) is engaged with a rack tooth (11,11') integral with the terminal link (10) of the clasp, towards a second position in which the toothed element (7) is released from its engagement with the rack teeth (11, 11'), the clasp being characterized in that the control member (6) is accessible from the cap (3) through an opening (34) formed in the cap, the control member comprising at least one housing (62) in which a return spring (14) is disposed, this spring (14) bearing against the frame and in that it comprises at least one other spring (15) arranged in a housing of the cap to push the terminal link (10) into the second position where it is totally disengaged from the cap (3) when the control member is actuated.

Description

TECHNICAL FIELD

[0001] The present invention relates to a bracelet clasp, of the folding buckle type, which allows adjustment of the usable length of the bracelet.

[0002] The present invention also relates to a wristwatch equipped with such a clasp. EARLIER ART

[0003] The issue of the need to provide a mechanism for adjusting the usable length of a bracelet is well known.

[0004] On the one hand, in the case of link bracelets, the wearer's wrist circumference may fall between two bracelet configurations differing by only one link. Therefore, it is useful to include a mechanism for adjusting the bracelet's usable length, allowing for finer adjustments than simply removing or adding a link.

[0005] Furthermore, it is also known that wrist circumference varies with the seasons, generally reaching its maximum in summer and its minimum in winter. Wrist circumference can also vary throughout the day. Therefore, it is advisable to include a fine-tuning mechanism for the bracelet's length, allowing the wearer to adjust it for optimal comfort.

[0006] As an example, patent EP 0 350 785 B1 describes a clasp comprising a device for adjusting the usable length of the bracelet that can be operated without tools. The clasp described in this patent is of the folding buckle type, comprising two blades hinged together by means of a rod passing through both of them. Each blade has a strap attachment element at its free end. The first blade has a hook designed to engage in a hole in the second blade, where it engages with a trigger mechanism that locks the hook, and thus the clasp, in the closed position. The second blade comprises two parts that can slide relative to each other within a predefined range, defining an adjustment increment for the usable length of the bracelet. One of these two parts has the hinge connecting it to the first blade, while the second part has the locking trigger mechanism.The hole into which the hook engages to lock the clasp has a length, along the longitudinal direction of the bracelet, corresponding to the sliding range between the two parts of the second blade. The trigger has a central portion defining two positions for the hook, along the longitudinal direction of the bracelet, corresponding to two different usable lengths of the bracelet. A control mechanism, including a push button, allows the trigger to be activated to release the hook and open the clasp.

[0007] One drawback of this design is that the bracelet length setting is lost each time the clasp is opened. Therefore, the wearer must ensure that the clasp is inserted on the side of the central portion of the trigger corresponding to the desired bracelet length each time it is closed.

[0008] Adjustment devices incorporating a specific locking mechanism have also been proposed as an alternative to avoid this type of inconvenience. SUMMARY OF THE INVENTION

[0009] The present invention aims to remedy the aforementioned drawbacks and others by providing a clasp for fine-tuning the length of a watch strap, allowing the strap length setting to be maintained without risk of inadvertent loss, and providing a particularly simple and quick handling and adjustment.

[0010] To this end, the present invention relates to a watch strap clasp comprising a cap connected on one side to a first strap strand and on the other side to a second strap strand, with connecting means interposed between the second strap strand and the clasp cap, these connecting means comprising a sliding end link along a longitudinal direction of the clasp between the cap and a frame fixed to the cap, from a first position in which the end link is engaged in the clasp cap, to a second position in which the end link is disengaged from the clasp cap, the clasp comprising a pressure-operated control member for moving a toothed element fixed to the control member from a first position in which the toothed element is engaged with a rack tooth fixed to the end link of the clasp,towards a second position in which the toothed element is freed from its engagement with the rack teeth.

[0011] According to the invention, the control member is accessible from the cap through an opening formed in the cap, the control member comprising a housing in which at least one return spring is disposed, this spring bearing against the frame, the clasp also comprising at least one spring arranged in a housing of the cap to push the terminal link into the second position where it is totally disengaged from the cap when the control member is actuated.

[0012] In accordance with other advantageous variants of the invention: The toothed element translates between a locked position and an unlocked position, the toothed element having teeth arranged to cooperate with the rack teeth of the terminal link and form distinct adjustment positions; the spring passes through the toothed element and bears against the frame and the control member; the cap has a general U-shaped cross-section and is provided with two facing wings, each wing having an opening to receive the first and second pushers; the pushers have a head and a body, the head of each pusher resting in one of the openings and the body comprising a hook arranged to cooperate with the first blade and hold the clasp in the closed position on the blades; the frame has machining on part of its thickness to delimit the stroke length of the control member and the locking means;The frame includes two through holes arranged for the passage of the pusher hooks; the control member includes at least one cavity arranged to receive a spring; the sliding tip includes stop means preventing the sliding tip from dislodging from the cap; the toothed sector has a plurality of teeth, each tooth defining an indexed position of the sliding tip; the toothed sector has a plurality of teeth, each tooth defining an indexed position of the sliding tip; the toothed sector includes teeth of asymmetrical shape such that a first portion of the tooth is perpendicular to the direction of movement of the sliding tip, and the second portion of the tooth has a slope; the toothed element of the lever has a shape complementary to the asymmetrical shape of the teeth of the toothed sector. BRIEF DESCRIPTION OF THE FIGURES

[0013] Other features and advantages of the present invention will become clearer from the following detailed description of an embodiment of the watch strap or belt clasp according to the invention, this example being given purely for illustrative purposes and not as a limitation, only in connection with the accompanying drawing in which: there figure 1 is a perspective view of the clasp of the figure 1 in its assembled state; the figure 2 is an exploded perspective top view of the clasp of the figure 1 ; there figure 3 is an exploded perspective view of the underside of the clasp of the figure 1 . DETAILED DESCRIPTION

[0014] The invention will now be described in connection with a watch strap. figure 1 is an assembled perspective view of the clasp according to the invention, while the figures 2 And 3 are exploded perspective views of the same clasp.

[0015] The clasp according to the invention comprises a cap 3 connected on one side to a first strap strand (not shown in the figures) with an interposed folding clasp system comprising first and second blades 1, 2, the structure of which is known per se and will therefore not be described further here. It should be noted that the folding clasp system can be omitted and that the cap 3 can be connected directly to the first strap strand. The cap 3 is connected on a second side to a second strap strand (not shown in the figures) via a terminal link 10 for fine-tuning the strap length.

[0016] As can be seen at the figure 1The cap 3 has a general U-shaped section and is provided with two facing wings 30, each of these wings 30 having an opening 31 arranged to receive a pusher 4, 5. The pushers 4, 5 each have a head 40, 50 and a body 41, 51) the head of each pusher resting in one of the openings 30 and the body 41, 51 comprising a hook 42, 52 arranged to cooperate with the first blade 1 and to hold the clasp in the closed position on the blades 1, 2.

[0017] Furthermore, two housings 32 are provided in the bottom of the cap 3 to receive return means 43, 44 exerting a return force on the pushers.

[0018] The cap 3 also includes lateral guide surfaces to guide the end link 10 as it slides within the cap 3 between the base of the cap 3, the wings 30, and a frame 8 attached to the cap and closing the U-shaped section of the cap 3. The end link 10 is able to slide along a longitudinal direction of the clasp 1 between a first position in which the end link 10 is engaged in the cap 3, and a second position in which the end link 10 is completely disengaged from the cap 3 of the clasp 1. The length available for adjusting the bracelet is thus determined by the stroke of the end link 10 between its first and second positions.

[0019] The cap 3 further includes at least one groove and preferably two grooves 33, in each of which is arranged a helical spring 15, these springs 15 extending in the direction of the length of the clasp and being constrained by the terminal link 10 when it is mounted in the cap 3.

[0020] The terminal link 10 also includes at least one, and preferably two segments with a rack and pinion toothing 11, 11', the segments extending into corresponding housings in the cap 3. These segments with a rack and pinion toothing are intended to engage with a toothed element 7 having teeth 70, the toothed element 7 being actuated by a control member 6 accessible from the cap 3 by the carrier.

[0021] As can be seen in the figures, the control member 6 is in the form of a push button accessible from the upper face of the cap 3 via an opening 34. The push button 6 is attached to the toothed element 7 via a screw 72 but could also be welded, so as to move the toothed element 7 simultaneously with the push button 6.

[0022] The push button 6 has an actuation surface 60 and a body 61, the push button being linked to the toothed element 7 via its body 61. The body 61 includes two blind holes 62 arranged to receive at least two springs 14 passing through the toothed element 7 via holes 72 formed in the toothed element 7, and bearing against the frame 8. Once the clasp is assembled, the segments having the rack teeth 11, 11' move between the push button 6 and the toothed element 7 on either side of the body 61 of the push button 6, the height of the body 61 allowing a space for the passage of the rack teeth.

[0023] Thus, when the wearer presses (or pushes) on the push-button 6 against the elastic return force of the springs 14, the toothed element 7 is released from its engagement with the rack teeth 11, 11', and the terminal link 10 is also moved and totally disengaged from the cap 3 under the effect of the pair of springs 15.

[0024] To prevent the terminal link 10 from dislodging from the cap 3, stop and guide means 13 are provided on the latter and cooperate with a machining 33 formed on the bottom of the cap 3. This machining forms both a stop and the available stroke length for the terminal link.

[0025] We also observe upon examination of the figure 3 that a machining 80 is provided on part of the thickness of the frame 8 to delimit the stroke length of the control member 6 and of the toothed element 7, and at least one stud 81 is formed in the machining 80 for the centering of the spring 14.

[0026] The frame 8 also includes two through holes 82, adjacent to the machining 80, and arranged for the passage of the hooks 42, 52.

[0027] Thus, to adjust the clasp, the user presses the push-button 6 accessible from the cap 3, which causes the toothed element 7 to move and allows the toothed element 7 to be disengaged from the rack teeth 11, 11'.

[0028] When the toothed element 7 is disengaged, the terminal link 10 is free and moves in translation until it reaches its stop under the action of the spring pair 15, the terminal link 10 is then totally free from the cap 3 and the user can release the push button.

[0029] Finally, to adjust the desired bracelet length, the user manipulates the bracelet strand attached to the terminal link 10 to partially retract the latter into the cap 3 in the desired position, the association of the toothed element 7 with the rack teeth 11, 11' forming a disengageable click and allowing the user to feel the passage from one tooth to the next during the adjustment.

[0030] It is understood that the present invention is not limited to the embodiment just described and that various simple modifications and variants may be envisaged by a person skilled in the art without departing from the scope of the invention as defined by the attached claims.

Claims

1. Watch strap clasp (100) comprising a cap (3) connected on one side to a first strap strand and on the other side to a second strap strand, connecting means being interposed between the second strap strand and the cap (3) of the clasp (1), these connecting means comprising an end link (10) sliding along a longitudinal direction of the clasp (1) between a frame (8) integral with the cap and the cap (3), from a first position in which the end link (10) is at least partially engaged in the cap (3) of the clasp (1), to a second position in which the end link (10) is disengaged from the cap (3) of the clasp (1), the clasp comprising a pressure-operated control member (6) for moving a toothed element (7) integral with the control member (6) from a first position in which the toothed element (7) is engaged with a rack toothing (11, 11') integral with the link terminal (10) of the clasp,to a second position in which the toothed element (7) is released from its engagement with the rack teeth (11, 11'), the clasp being , characterized in that The control member (6) is accessible from the cap (3) through an opening (34) formed in the cap, the control member comprising at least one housing (62) in which a return spring (14) is disposed, this spring (14) bearing against the frame and in that it includes at least one other spring (15) arranged in a housing in the cap to push the terminal link (10) into the second position where it is totally disengaged from the cap (3) when the control member is actuated.

2. Clasp (100) according to claim 1, characterized in thatthe toothed element (7) translates between a locked position and an unlocked position, the toothed element (7) having teeth (70) arranged to cooperate with the rack teeth (11, 11') of the terminal link (10) and form distinct adjustment positions.

3. Clasp (100) according to claim 1 or 2, characterized in that the springs (14) passing through the toothed element (7) and bearing on the frame (8) and the control member (6).

4. Clasp (100) according to any one of the preceding claims, characterized in that the headgear (3) has a general U-shaped section and is provided with two wings (30) facing each other, these wings (30) each having an opening (31) to receive the first and second pushers (4, 5).

5. Clasp (100) according to any one of the preceding claims, characterized in thatthe pushers (4, 5) have a head (40, 50) and a body (41, 51), the head of each pusher resting in one of the openings (30) and the body (41, 51) comprising a hook (42, 52) arranged to cooperate with the first blade (1) and hold the clasp in the closed position on the blades (1, 2).

6. Clasp (100) according to any one of the preceding claims, characterized in that the frame (8) has a machining (80) on part of its thickness to delimit the stroke length of the control element and the locking means.

7. Clasp (100) according to claim 5 or 6, characterized in that the frame (8) includes two through holes (82) arranged for the passage of the hooks (42, 52).

8. Clasp (100) according to any one of the preceding claims, characterized in that the control member (6) includes at least one cavity (60) arranged to receive a spring (14).

9. Clasp (100) according to claim 4, characterized in thatthe sliding tip (10) includes stop means (13) preventing the sliding tip (10) from dislodging from the cap (3).

10. Clasp (100) according to any one of the preceding claims, characterized in that the toothed sector (15) has a plurality of teeth, each tooth defining an indexed position of the sliding tip.

11. Clasp (100) according to any one of the preceding claims, characterized in that the toothed sector (15) includes teeth of asymmetrical shape such that a first portion of the tooth is perpendicular to the direction of movement of the sliding tip, and the second portion of the tooth has a slope.

12. Clasp (100) according to claim 11, characterized in that the toothed element (62) of the lever (6) has a shape complementary to the asymmetrical shape of the teeth of the toothed sector.

Images