EP2875747A1 - Bracelet clasp comprising a device for adjusting the useful length of the bracelet - Google Patents

Abstract

The present invention relates to a clasp (1) for a bracelet, comprising a device (42, 52, 58, 60, 76) for adjusting the useful length of the bracelet, comprising a carriage (42) slidable inside a frame (26) in the longitudinal direction of the bracelet, the carriage (42) carrying a longitudinal locking member (52), arranged to cooperate with an indexing member (76) integral with the frame (26) and, assembled to the carriage (42) such that it is movable between a first locking position, in which it cooperates with the indexing member (76), and a second setting position, in which it is out of range of the indexing member (76) to allow movement of the carriage (42). The carriage (42) carries an elastic return member (60) arranged to exert a force on the longitudinal locking member (52) and tend to position it in the locking position.

Description

Technical area

The present invention relates to a clasp for a bracelet of the type comprising first and second free ends, the clasp comprising first and second bracelet fastening devices intended to be secured respectively to the first and second free ends of the bracelet, the fastening devices being movable relative to each other between at least one open configuration and one closed configuration, of service, in which they are closer to each other than in the open configuration, to close the bracelet and to define a useful length, the clasp also comprising means for locking the fastening devices of the bracelet in their closed configuration.

Clasps of this type are commonly referred to as "folding clasp" clasps and are typically associated with wristwatches.

State of the art

A folding clasp can be associated with a metal bracelet, or ceramic, and the latter generally has a fixed service length, defined by the number of links component. Alternatively, a clasp with folding clasp can be associated with a flexible bracelet, usually leather, rubber, or even synthetic material. In this case, the bracelet has a plurality of holes capable of cooperating with the clasp to adjust its useful length.

However, in either case, the possible settings of the useful length of the bracelet are quite coarse and it is possible that the perimeter of the wrist of the wearer of the corresponding watch is between two adjacent settings.

It is then preferable to provide the implementation of a fine adjustment device of the useful length of the bracelet.

According to the present invention, the first strap fastening device comprises a frame carrying a device for adjusting the effective length of the strap. bracelet comprising a carriage intended to be secured to the first free end of the bracelet and capable of sliding inside the frame in the longitudinal direction of the bracelet, the carriage carrying a longitudinal locking member arranged to cooperate with an indexing member secured to the frame, to maintain the carriage in a predefined position relative to the frame. In addition, the longitudinal locking member is assembled to the carriage so that it is movable, with reference to the latter, between at least a first locking position, in which it cooperates with the indexing member, and a second setting position, in which it is out of range of the indexing member to allow relative movement between the carriage and the frame.

The patent EP 1908366 B1 describes a clasp of this type. More specifically, this document discloses a clasp construction associated with a metal bracelet formed of a plurality of links. The carriage described in this patent is substantially in the form of a link having lateral guide members arranged in guide grooves formed in the lid of the clasp. The lateral guide members have an extended dimension, in the longitudinal direction of the bracelet, to limit the number of degrees of freedom of the carriage to one, that is to say that it can only slide to follow the curve guide grooves. The carriage carries a locking tooth oriented towards the inside of the lid of the clasp to cooperate with a rack formed in the corresponding wall of the lid. In a first embodiment, the locking tooth is carried by an additional link, linked to the carriage by a pivot type connection. Thus, the additional link can rotate between a locked position, maintained by notch, and a free position in which the tooth is no longer located opposite the rack, to allow movement of the carriage.

However, it should be noted that the construction of this clasp is relatively complex and has a limited ease of implementation when it comes to adjusting the useful length of the bracelet. Indeed, once the carriage released, the user must be very attentive to the amplitude of its sliding to achieve a fine adjustment of the useful length of the bracelet. Thus, it is likely that the user has to proceed by trial and error only to move the carriage of a single tooth rack. In particular, it is likely that the setting is changed at the time of the introduction of the additional link to lock the carriage in the desired position, since the user must hold both the bracelet, the clasp cover and the cart, while manipulating the extra link to rotate it in its notch. Note also that the useful length of the bracelet can be adjusted only when the clasp is in its open configuration, while it could be advantageous to adjust it in the direction of a decrease in its useful length while it is worn on the wrist, that is to say when the clasp is in its closed configuration.

Disclosure of the invention

A main object of the present invention is to provide an alternative to known clasps of the prior art, by providing a bracelet clasp comprising a device for adjusting the useful length of the bracelet structure and simple handling.

To this end, the present invention relates more particularly to a bracelet clasp of the type mentioned above, characterized in that the carriage carries a resilient return member arranged to exert a force on the longitudinal locking member and tend to position it. in the locking position.

Thanks to these characteristics, the clasp according to the invention allows easier handling than the clasps of the state of the art, in particular by virtue of the fact that it is sufficient to release the longitudinal locking member so that it resumes its position. locked. Thus, it is particularly easier to make a stepwise adjustment of the useful length of the bracelet with the clasp of the prior art mentioned above.

Preferably, the frame has the shape of an elongated lid, in the longitudinal direction of the bracelet, having two walls lateral, located on either side of an upper wall and, each of which comprises a guide groove of the carriage.

In addition, it can advantageously be provided in this case that the carriage has a central portion delimited by two lateral portions, each of which comprises a guide pad arranged in the corresponding guide groove.

With these additional features, the manipulation of the useful length adjustment device is simplified insofar as the possibilities of movement of the carriage are limited.

In addition, it is also possible that the longitudinal locking member is preferably pivotally mounted on the carriage, a rod being arranged transversely between the lateral portions, being housed through a suitable hole in the longitudinal locking member. to define an axis of rotation for the latter.

According to a preferred embodiment, the longitudinal locking member comprises at least one tooth cooperating with at least one rack formed in the elongate lid. In addition, an additional groove may advantageously be formed in the cover being arranged to cooperate with a maximum travel finger assembled to the carriage detachably.

In this case, it can also be provided that the additional groove is formed in the upper wall of the cover, the maximum stroke finger being assembled to the central portion of the carriage.

According to a preferred embodiment, the rack has an asymmetrical toothing, so that the useful length of the bracelet can be reduced by the exclusive and simultaneous exercise of forces on the first and second fixing devices of the bracelet to bring them closer to each other. one of the other, regardless of the open or closed configuration of the clasp.

Thanks to these characteristics, the bracelet can be shortened easily while the corresponding watch is worn on the wrist.

Furthermore, it can also be provided that the longitudinal locking member has a bearing surface, accessible to a user when the clasp is in its open configuration and arranged in such a way that a pressure exerted on it is likely to move the longitudinal locking member from its locking position to its adjustment position.

The present invention also relates to a bracelet with a clasp according to the characteristics that have just been exposed.

Brief description of the drawings

Other features and advantages of the present invention will appear more clearly on reading the detailed description of a preferred embodiment which follows, made with reference to the accompanying drawings given by way of non-limiting examples and in which:

- the figure 1 is an exploded perspective view of a bracelet clasp according to a preferred embodiment of the present invention;

- the figure 2 represents a simplified perspective view, in partial transparency, of a construction detail of the clasp of the figure 1 ;

- the figure 3 represents a simplified longitudinal sectional view of the clasp of the figure 1 in a first configuration;

- the figure 4 represents a simplified longitudinal sectional view of the clasp of the figure 1 in a second configuration, and

- the figure 5 represents a simplified longitudinal sectional view of the clasp of the figure 1 in a third configuration.

Mode (s) of realization of the invention

The clasp illustrated in a nonlimiting manner in the figures corresponds to a preferred embodiment of the present invention. In particular, the clasp 1 is of the clasp type and is particularly intended to close a wristwatch timepiece.

It should be noted more specifically that the conventional part of the clasp illustrated by way of example, that is to say outside fine adjustment device of the useful length of the bracelet, is described in detail in the patent. EP 0 913 106 B1 , issued in the name of the Applicant.

The clasp 1 is intended to be connected to two free ends of a bracelet (not shown) in a known manner.

As described in the patent EP 0 913 106 B1 mentioned above, the clasp comprises a base 2, elongated in the longitudinal direction of the bracelet and slightly curved over at least a portion of its length to better fit the shape of the wrist of a wearer. The base 2 comprises two longitudinal members 4 spaced from each other by being integral with a transverse spacer 6 disposed at a first end of the longitudinal members 4. The spacer comprises a cylindrical bore 8 intended to house a bar 10, itself even housed in a hollow tube 12, to ensure the attachment of the base 2 to a terminal link 14, via a suitable hole 13 thereof. The latter is itself a fixing device intended to be connected to a first free end of the bracelet, via a bar or rod (not visible) intended to be housed in a hole 15 adapted to the end link 14.

A folding arm 16 formed by two branches 18, 20 is pivotally mounted at the opposite end of the longitudinal members 4, in a conventional manner.

The opposite ends of the branches 18, 20 have guns 22, each provided with a hole 24.

The pair of holes 24 is provided to ensure the assembly of the folding arm 16 to a lid 26 of the clasp, by means of two lateral pushers 28 each of which is secured to a rod 30 engaging in the corresponding hole 24, with interposition of a socket 32.

Springs 34 are interposed between the cover 26 and each of the pushers 28 to exert on them a force tending to keep them away from each other.

The pushers 28 are arranged to act on the branches 18, 20 to bring them closer to each other when they are actuated by a user wishing to open the clasp 1. The relative approximation of the branches 18, 20 has the effect to release claws 36 formed on the branches 18, 20 and inserted in complementary recesses 38, formed in the base 2, as has been described in detail in the patent EP 0 913 106 B1 .

Washers 40 defining stable bearing surfaces on either side of the springs 34 are also provided, by way of nonlimiting illustration.

The device for adjusting the useful length of the bracelet according to the invention is associated with the basic structure of the clasp 1, being housed in particular under the lid 26.

The adjusting device comprises a carriage 42 slidably mounted inside the lid 26.

The carriage 42 has a central portion 44 delimited by two lateral portions 46.

The lateral portions 46 are substantially elongated in the longitudinal direction of the bracelet. They are provided with holes 48 intended to cooperate with a strip for fixing a bracelet strand (not shown), near a first of their ends. They furthermore comprise additional holes 50, near the other end, intended to allow the assembly of a longitudinal locking member 52, so that the latter is pivotally mounted on the carriage 42. locking 52 is thus assembled to the carriage 42 by use of a rod 54 housed in a sleeve 56, by way of example.

The longitudinal locking member 52 comprises two locking teeth 58 located opposite the central portion 44 of the carriage 42, the return springs 60 being interposed between the teeth 58 and the central portion 44 of the carriage 42, so that they exert a repulsive force on the teeth 58 tending to move them away from the carriage 42, to define a locking position of the longitudinal locking member 52, as will emerge more clearly from the detailed description of the following figures.

The central portion 44 of the carriage 42 furthermore comprises a support 62 to which is assembled a maximum travel finger 64, by means of a screw 66.

The figure 2 represents a simplified perspective view, in partial transparency, of the lid 26.

The cover has two side walls 68 inside which are formed guide grooves 70, each of which has a curvature identical to that of the lid 26 and is open at one of its ends coinciding with one end of the side wall 68 corresponding.

Each guide groove 70 is intended to cooperate with a guide pad 72 (one of which is visible on the figure 1 ) provided on the corresponding lateral portion 46 of the carriage 42.

Thanks to these characteristics, the carriage 42 can be engaged under the cover 26, by engagement of the guide pads 72 in the guide grooves 70, to be able to slide there. The guiding shoes 72 preferably have an elongate shape in the longitudinal direction of the wristband, so that the trolley 42 can move only by sliding along the guide grooves 70.

The lid 26 has an upper wall 74 inside which are provided indexing members, namely here two racks 76 with asymmetrical teeth.

Each of these racks 76 is located facing one of the teeth 58 of the longitudinal locking member 52 to cooperate with it and to index the carriage 42 with reference to the cover 26.

Furthermore, an additional groove 78 is formed inside the upper wall 74, between the two racks 76, the latter being closed at both ends. The additional groove 78 is intended to cooperate with the maximum stroke finger 64 carried by the carriage 42 to define a maximum stroke amplitude for the latter. Thus, once the carriage 42 is inserted under the cover, the maximum travel finger 64 is screwed onto its central portion 44 to secure it to the cover 26 and prevent it from sliding to the point of escaping out of the guide grooves 70.

The figures 3 , 4 and 5 represent a simplified longitudinal sectional view of the clasp 1, in first, second and third respective configurations and allow to better illustrate the operation of the clasp 1 according to the present invention.

The figures 3 and 4 represent the clasp 1 while it is in its closed configuration and illustrate how the useful length of the bracelet can be decreased without opening it.

The mode of cooperation between the locking teeth 58, carried by the carriage 42, and the racks 76 is more clearly visible in these figures, as is the asymmetrical nature of the toothings of the racks 76.

Thus, it appears that when the user exerts a force on the strap strand secured to the carriage 42, in the direction indicated by the arrow F on the figure 3 the cover being held in a fixed position, this force is transmitted to the teeth 58 via the racks 76. This force, opposing the force exerted by the springs 60 on the teeth 58, causes a pivoting of the longitudinal locking member 52 in the clockwise direction, passing it in the state illustrated on the figure 4 , in which the teeth 58 are out of reach of the racks 76.

In this state, the carriage 42 is free to slide stepwise along the guide grooves 70, towards the left on the figures 3 and 4 , in a direction of shortening of the bracelet.

On the contrary, it is clear from figures 3 and 4 that traction of the same bracelet strand, integral with the carriage 42, in the opposite direction to that indicated by the arrow F has no effect, the teeth 58 cooperating with the racks 76 to ensure the locking of the carriage 42. Thus, the bracelet can not be lengthened when the clasp 1 is in its closed configuration.

Advantageously, the length of the guide grooves 70 is adjusted so that when the guide shoes 72 arrive at the end of the stroke, the teeth 58 are engaged in the last hollow of the corresponding rack.

The figure 5 represents the clasp 1 while it is in its open configuration and illustrates how the bracelet can then be lengthened. Specifically, the clasp is illustrated on the figure 5 in a configuration corresponding to a useful length of the minimum bracelet.

To allow the carriage 42 to slide, it is necessary to rotate the longitudinal locking member 52 in the clockwise direction. For this purpose, it has a bearing surface 80 located in the extension of the central portion 44 of the carriage 42, in the longitudinal direction of the bracelet.

When the clasp 1 is in its open configuration, the bearing surface 80 is accessible to the user as is apparent from the view of the figure 5 .

It can then exert pressure on the bearing surface 80, as shown schematically by the arrow F on the figure 5 , to overcome the force exerted by the springs 60 on the teeth 58, and to pivot the longitudinal locking member 52. The latter then finds itself in a configuration similar to that illustrated in FIG. figure 4 , allowing the carriage 42 to slide along the guide grooves 70 to lengthen the bracelet.

Note that, if the adjustment of the useful length of the bracelet can be achieved extremely accurately when it is shortened, because the carriage 42 necessarily moves step by step, it is also possible for the user to play on the inclination of the locking member 52 and feel the teeth of the racks 76 when extending the bracelet.

Thanks to these characteristics, the clasp 1 according to the present invention offers a possibility of fine adjustment of the useful length of a bracelet reliably, robustly and accurately, while its construction remains relatively simple and inexpensive with reference to certain clasps known in the state of the art.

It will be noted that, advantageously, the upper wall 74 of the lid 26 also comprises a transverse groove 82 into which is inserted a protective pad 84 intended to prevent the links of the bracelet from contacting the lid, when the bracelet is shortened, which could cause the appearance of scratches. Also, the protective pad 84 may be made of rubber, teflon or any other suitable material.

The foregoing description attempts to describe a particular embodiment by way of non-limiting illustration and the invention is not limited to the implementation of certain particular features which have just been described, for example the forms specifically illustrated and described for the cover, the pushers or the fastening devices of the bracelet. It will also be recalled that the clasp according to the present invention can be associated just as much with a flexible bracelet, leather, rubber or textile, as with a rigid type of bracelet, such as a metal bracelet, or even ceramic.

The skilled person will not encounter any particular difficulty to adapt the content of the present disclosure to his own needs and implement a clasp, especially for a timepiece, without departing from the scope of the present invention. It will be noted, for example, that the adaptation of the present teaching for the construction of a conventional folding clasp of the type with three superimposed Z-blades will not pose any particular difficulty to the person skilled in the art, as well as for the construction of a clasp having different locking means.

Furthermore, the clasp according to the present invention is not limited to the implementation of two racks in the lid or the fact that they are formed in the upper wall of the lid, as well as the additional groove of delimitation of the maximum race. In addition, the longitudinal locking member may be movable in translation on the carriage, alternatively, being for example actuated via a lever arm without departing from the scope of the present invention.

Claims (12)

Clasp (1) for a bracelet of the type comprising first and second free ends, the clasp (1) comprising
first and second fixing devices (14, 15, 26, 42, 48) of the bracelet intended to be secured respectively to said first and second free ends of the bracelet, said fixing devices (14, 15, 26, 42, 48). being movable relative to one another between at least one open configuration and one closed service configuration, in which they are closer to one another than in the open configuration, to close the wristband and to define a useful length,
locking means (36, 38) of said fasteners (14, 15, 26, 42, 48) of the bracelet in their closed configuration,
the first fastening device of the bracelet comprising a frame (26) carrying a device (42, 52, 58, 60, 76) for adjusting the useful length of the bracelet comprising a carriage (42) intended to be secured to said first end free bracelet and slidable within said frame (26) in the longitudinal direction of the bracelet, said carriage (42) carrying a longitudinal locking member (52) arranged to cooperate with an indexing member (76) solidaire said frame (26) for maintaining said carriage (42) in a predefined position relative to said frame (26), said longitudinal locking member (52) being assembled to said carriage (42) in such a manner that it is movable, with reference to the latter, between at least one first locking position, in which it cooperates with said indexing member (76), and a second setting position, in which it is out of reach of said index member ion (76) to allow relative movement between said carriage (42) and said frame (26),
characterized in that said carriage (42) carries an elastic return member (60) arranged to exert a force on said longitudinal locking member (52) and tend to position it in said locking position. Clasp (1) according to claim 1, characterized in that said frame has the shape of a lid (26) elongate, in the longitudinal direction of the bracelet, having two side walls (68), located on either side of 'a upper wall (74) and each of which comprises a guide groove (70) of said carriage (42). Clasp (1) according to claim 2, characterized in that said carriage (42) has a central portion (44) delimited by two lateral portions (46), each of which comprises a guide pad (72) arranged in said guide groove (70) corresponding. Clasp (1) according to claim 3, characterized in that said longitudinal locking member (52) is pivotally mounted on said carriage (42). Clasp (1) according to claim 4, characterized in that a rod (54) is arranged transversely between said lateral portions (46), being housed through an adapted hole in said longitudinal locking member (52) to define an axis of rotation for the latter. Clasp (1) according to any one of claims 3 to 5, characterized in that said lateral portions (46) further comprise holes (48) for fixing a bracelet strand. Clasp (1) according to any one of claims 2 to 6, characterized in that said longitudinal locking member (52) comprises at least one tooth (58) cooperating with at least one rack (76) formed in said cover (26). ). Clasp (1) according to claim 7, characterized in that an additional groove (78) is formed in said cover (26) being arranged to cooperate with a maximum travel finger (64) assembled to said carriage (42) so as to removable. Clasp (1) according to claim 8, characterized in that said additional groove (78) is formed in said upper wall (74) of said cover (26), said maximum stroke finger (64) being assembled to said central portion (44). ) of said carriage (42). Clasp (1) according to any one of claims 7 to 9, characterized in that said rack (76) has an asymmetrical toothing, so that the useful length of the bracelet can be reduced by the exclusive and simultaneous exercise of forces on said first and second fixing devices (14, 15, 26, 42, 48) of the bracelet to bring them closer to each other, regardless of the open or closed configuration of the clasp (1). Clasp (1) according to any one of the preceding claims, characterized in that said longitudinal locking member (52) has a bearing surface (80) accessible to a user when the clasp (1) is in its open configuration and arranged such that pressure exerted thereon is capable of moving said longitudinal locking member (52) from its locking position to its adjustment position. Wristwatch comprising a bracelet with a clasp (1) according to any one of the preceding claims.

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