Device for adjusting the useful length of a bracelet and clasp comprising such a device

Abstract

Device (1) for adjusting the usable length of a bracelet comprising a cover (6) to which a first end (20a) of a bracelet is fixed and comprising at least two side walls (6a) extending along the longitudinal axis of the bracelet, two lateral racks (2) comprising at least two teeth (2a), the racks being integral with the side walls (6a) of the cover (6) and a carriage (3) configured to be made integral with the second end (20b) of the bracelet and capable of moving relative to the lateral racks (2), the carriage (3) comprising a locking element (4) configured to cooperate with the teeth (2a) of the lateral racks (2) to ensure that the carriage (3) is held in a predefined position relative to the racks (2), the locking member (4) being assembled to a push button (8) of the carriage (3) such that the locking member (4) is movable, with respect to the carriage (3),between at least a first position, locking, in which it cooperates with the teeth (2a) of the racks (2), and a second position, adjusting, in which it is out of reach of the teeth (2a) of the racks (2) to allow relative movement between the carriage (3) and the racks (2), the carriage (3) comprising at least one elastic member (5) acting on the push button (8) and tending to move the locking member (4) towards the bottom of the notches (2b) formed between the teeth (2a) of the racks (2), thus locking the locking member (4) in the notches (2b), wherein the profile of the teeth (2a) of the racks (2) is configured such that when a determined pushing force is exerted by a user on the carriage (3) or on the wrist strap connected to the carriage (3) in a longitudinal direction from the second end (20b) to the first end (20a),The force is transmitted to the locking member (4) in such a way as to disengage the locking member (4) from the teeth (2a) of the racks (2) and to generate a displacement of the carriage (3) in the longitudinal direction resulting in the shortening of the usable length of the bracelet.

Description

Technical field of the invention

[0001] The present invention relates to a device for finely adjusting the useful length of a bracelet, in particular a device for shortening the bracelet when the bracelet clasp is closed. The present invention also relates to a clasp comprising a device according to the present invention. State of the art

[0002] Wristwatches have been widely adopted around the world for their practical time-tracking functions and, more recently, for their health-tracking capabilities and mobile connectivity. A crucial aspect of a wristwatch's comfort and utility is how it fits the wearer's wrist. Traditionally, a watch's strap must be adjusted to fit the wearer's wrist size.

[0003] Currently, there are several methods for adjusting the size of watch straps. For example, some watches use a removable link system, allowing the user to add or remove links to adjust the size. However, this process is generally tedious and often requires the help of a specialist or the use of specific tools. Other types of watches use a rubber or silicone strap with a buckle, similar to a belt, but this does not allow for a fine adjustment and can cause discomfort if the strap is too tight or too loose.

[0004] Another method for adjusting the size of a watch strap is to use a folding clasp, which can be extended or retracted to fit the user's wrist size. However, these clasps can be complex to use, especially for the elderly or those with dexterity issues. Additionally, they usually cannot be adjusted while wearing the watch, which can be inconvenient for the user.

[0005] Current methods of adjusting watch strap size have several drawbacks. First, they are often laborious and require specialized tools or professional assistance, which may not be readily available to all users. Second, they do not allow for fine adjustment of the size, which can cause discomfort if the strap is too tight or too loose. Finally, they do not allow the user to adjust the strap size while wearing the watch, which can be inconvenient and hinder daily use of the watch.

[0006] In the field of watch straps, clasp systems with means for fine adjustment of the length are already known. These clasp systems offer the ability to slightly modify the length of a strap for a personalized fit, thus maximizing comfort when wearing the watch. These clasps generally include an end link, which connects one of the parts of the strap to the clasp cover. This end link is designed to slide along a longitudinal direction of the clasp to an extended position, where it disengages from the clasp. Therefore, the range of fine adjustment of the length is dictated by the movement of the end link between these two positions. To fix the position of the end link, a toothed element cooperates with a rack. For example, devices are known where the rack is attached to the clasp cover and the toothed element is located on the end link.These known devices are complicated to manufacture and are difficult to adapt to clasps of different widths. Finally, devices including a rack in the cover do not allow optimal guidance when finely adjusting the length.

[0007] The present invention aims to solve these problems and to provide a more convenient and efficient means of fine-tuning the length of a bracelet, for example a watch strap. The detailed description of the invention will be presented in the following sections of the patent application. Summary of the invention

[0008] The purpose of the present invention is to provide a more convenient and efficient means of finely adjusting the length of a bracelet, for example a watch strap.

[0009] According to the invention, these aims are achieved by the objects of the independent claims. The more specific aspects of the present invention are described in the dependent claims as well as in the description.

[0010] More specifically, an object of the invention is achieved by means of a device for adjusting the useful length of a bracelet comprising a cover to which a first end of a bracelet is fixed and comprising at least two side walls extending in the longitudinal axis of the bracelet, two lateral racks comprising at least two teeth, the racks being secured to the side walls of the cover and a carriage configured to be secured to the second end of the bracelet and capable of moving relative to the lateral racks, the carriage comprising a locking element configured to cooperate with the teeth of the lateral racks to ensure that the carriage is held in a predefined position relative to the racks, the locking member being assembled to a press button of the carriage in such a way that the locking member is movable, with reference to the carriage, between at least a first position,locking, in which it cooperates with the teeth of the racks, and a second, adjustment position, in which it is out of range of the teeth of the racks to allow relative movement between the carriage and the racks, the carriage comprising at least one elastic member acting on the push button and tending to move the locking member towards the bottom of the notches formed between the teeth of the racks, thus blocking the locking member in the notches, the profile of the teeth of the racks being configured such that when a determined pushing force is exerted by a user on the carriage or on the bracelet connected to the carriage in a longitudinal direction from the second end towards the first end,the force is transmitted to the locking member so as to disengage the locking member from the teeth of the racks and to cause the carriage to move in the longitudinal direction, resulting in the shortening of the useful length of the bracelet.

[0011] With such a device, it is possible to provide a clasp that allows the user to fine-tune the length of the clasp. When the clasp is closed, the user can easily shorten the bracelet by exerting force on the bracelet or the carriage in the direction of the first end. When the clasp is open, the user has access to the push button, which allows the user to easily shorten or lengthen the bracelet. In addition, thanks to the presence of the racks on both sides of the cover, the carriage is guided in the longitudinal direction during its movement, which allows precise movement. Thanks to the push button and the elastic member, it is guaranteed that the length of the bracelet cannot be changed inadvertently.

[0012] In a first preferred embodiment of the present invention, the carriage is configured to be secured to the last link of the second end of the bracelet. This allows the device to be used with a link bracelet, such as a metal link bracelet.

[0013] In another preferred embodiment of the present invention, the thrust force required to enable the carriage to move is determined at least in part by the profile and / or shape of the locking member and the notches intended to receive the locking member and / or by the spring constant of the elastic member. This makes it possible to provide devices which require different forces to enable the bracelet to be shortened when the clasp is closed.

[0014] In a preferred embodiment of the present invention, as seen in profile, the teeth comprise a first flank and a second flank, the first flank being oriented essentially perpendicular to the longitudinal axis of the bracelet and the second flank forming an angle with the longitudinal axis of the bracelet smaller than 90°, advantageously between 25° and 65°, even more advantageously between 35° and 55°, so that the second flank is inclined towards the first end of the bracelet. This makes it possible to provide a device with a handcuff effect. It is possible to shorten the bracelet by exerting a longitudinal force on the carriage but it is not possible to lengthen the bracelet by exerting a force in the opposite direction. This guarantees optimum safety. To lengthen the bracelet, it is necessary to open the clasp and act on the press button.

[0015] In another preferred embodiment of the present invention, the device is arranged to allow for shortening of length when the clasp is closed and the bracelet is worn by a user.

[0016] In another preferred embodiment of the present invention, the push button comprises a guide pin arranged to cooperate with notches in the side walls of the carriage. This allows the movement of the push button to be precisely guided.

[0017] In a preferred embodiment of the present invention, the side walls of the carriage comprise a cantilever arranged to cooperate with the upper edges of the racks so that the carriage can slide on these edges. This allows optimal guidance of the carriage during its movement and prevents dirt from entering the space between the carriage and the racks.

[0018] In another preferred embodiment of the present invention, the width of the carriage essentially corresponds to the distance between the racks. This allows the longitudinal movement of the carriage to be guided optimally.

[0019] In another preferred embodiment of the present invention, the racks are directly produced in the side walls of the cover. This allows for more space between the walls of the cover.

[0020] In another preferred embodiment of the present invention, the racks are secured to the cover by means of pins welded to the cover or by means of screws. This has the advantage that the racks are removable from the cover, which allows easier repair or service of the device.

[0021] In a preferred embodiment of the present invention, the locking member is arranged cylindrical and pivotable about its longitudinal axis. This allows, when the locking member is advantageously cylindrical, that the locking member can pivot on itself during the shortening movement, which guarantees that the wear of the teeth of the racks is very low over time.

[0022] Clasp for a bracelet comprising a bracelet length adjustment device according to one of the preceding claims. Such a clasp allows fine adjustment of the bracelet length. The bracelet can be shortened when the clasp is closed by acting on the bracelet itself by applying a longitudinal force in the shortening direction. It is possible to lengthen and shorten the bracelet when the clasp is open by acting on a push button which allows the locking member to be disengaged from the teeth of the racks and the carriage to be moved in the desired direction. Brief description of the drawings

[0023] The features and advantages of the present invention will appear in more detail in the context of the description which follows with an example of embodiment given for illustrative and non-limiting purposes with reference to the attached drawings which represent: There Figure 1is a perspective view of a clasp comprising a device according to one embodiment of the present invention; The Figure 2 is a perspective view of the same clasp as the Figure 1 but without the cover; The Figure 3 is a first perspective view of the racks and the carriage of the device of the present invention attached to the last link of the bracelet; The Figure 4 is a perspective view of the carriage of the device of the present invention attached to the last link of the bracelet; The Figure 5 is a perspective view of the carriage of the device of the present invention; The Figure 6 is a perspective and sectional view of the carriage of the device of the present invention in order to show the elastic members; and The Figure 7 is a first side view of the racks and carriage of the device of the present invention attached to the last link of the bracelet. Detailed description

[0024] There Figure 1shows a first perspective view of a device 1 for adjusting the useful length of a bracelet according to an embodiment of the present invention. This device comprises a cover 6 to which a first end 20a of a bracelet is fixed. The cover 6 comprises two side walls 6a extending in the longitudinal axis of the bracelet. The Figure 2 has the same device as the Figure 1 but without the cover 6. A device 10 can then be distinguished for opening a folding clasp. Such a device is known to those skilled in the art and will not be described in more detail here. A carriage 3 can also be distinguished comprising a locking member 4 which cooperates with the teeth 2a of the lateral racks 2 which are configured to be made integral with the lateral walls 6a of the cover 6 by means of pins 2c. As can be understood from the Figure 2, the carriage 3 is designed to be made integral with the second end 20b of the bracelet, here in the form of the last link of the bracelet. By comparing the Figures 3 to 5 , it is understood that the last link 20b is fixed to the carriage 3 by means of a cylindrical pin 3b in a manner similar to the fixing of the different links of a bracelet.

[0025] There Figure 3 shows a perspective view of the carriage 3, the racks 2 and the link 20b and allows the operation of the device of the present invention to be understood. As can be seen, the carriage 3 comprises a push button 8 to which the locking member 4 is fixed which allows the position of the carriage 3 to be fixed relative to the racks 2. In the various figures presented here, the carriage 3 is in the most extreme position corresponding to the shortest bracelet length which is adjustable by the device 1. In the position illustrated in the Figure 3, the locking member 4 is located at the bottom of a notch 2b formed by the teeth 2a of the racks 2. In order to be able to extend the length of the bracelet, it is easily understood that it is necessary to disengage the locking member from the teeth 2a. This is possible by means of the press button 8 which is accessible to the user when the clasp is open. When the locking member 4 is disengaged from the teeth 2a, it is possible for the user to move the carriage 3 and therefore the link 20b in order to extend the length of the bracelet. In order to allow good ergonomics, the press button comprises ridges 8a. So that the locking member 4 cannot disengage from the teeth 2a by itself, the carriage comprises elastic members 5 (see Figure 6), here in the form of spiral springs, which are compressed between the push button 8 and the cover 3a of the carriage 3. Thus, the springs 5 ​​push the locking member 4 to the bottom of the notches 2b of the racks 2 in order to fix the position of the carriage 3 and therefore of the link 20b.

[0026] As can be seen in the Figures 4 And 5, the push button also comprises a guide pin 8a which cooperates with notches provided on each side of the carriage 3 in order to guide the movement of the push button when the locking member of the teeth 2a is disengaged. It is also apparent from these figures that the carriage 3 comprises on each side a cantilever 3c configured to cooperate with the upper edges of the racks so that the carriage during movement slides on the racks which makes it possible to guide the movement of the carriage. Note that the presence of the cantilever 3c is optional. In addition, the width of the carriage 3 is chosen to be essentially equal to the lateral distance between the racks which guarantees that the movement of the carriage is only a movement along the longitudinal direction of the bracelet.

[0027] In reference to the Figure 7, the profile of the teeth 2a of the racks is, seen in profile, asymmetrical. The first flank 2a1 is oriented essentially perpendicular to the longitudinal axis B of the bracelet. This ensures that, even if the user exerts a tensile force in the direction D1 on the carriage 3 or on the link 20b without disengaging the locking member via the push button 8, the length of the bracelet cannot be extended. As explained above, to extend the bracelet, it is necessary to disengage the locking member 4 from the teeth 2b and then to exert a force in the direction D1. The second flanks 2a2 of the teeth 2 are inclined towards the first end of the bracelet. They therefore form with the longitudinal axis B of the bracelet an angle A which is smaller than 90°. This angle is advantageously between 25° and 65°, even more advantageously between 35° and 35°.The inclination of the second flanks 2a2 allows that when a determined pushing force is exerted by a user on the carriage 3 or on the link 20b in the direction D2, the force is transmitted to the locking member 4 so as to disengage the latter from the teeth 2a of the racks 2 and to cause a movement of the carriage 3 in the longitudinal direction resulting in the shortening of the useful length of the bracelet. The profile of the teeth 2a of the racks 2 therefore makes it possible to achieve a handcuff effect, that is to say that when the clasp is closed, it is possible for the user to shorten the length of the bracelet by exerting a pushing force along the direction D2 but it is not possible to lengthen the bracelet by exerting a pulling force in the direction D1. To extend the bracelet, it is necessary to open the bracelet to gain access to the push button 8 in order to disengage the locking member 4 from the teeth 2a.

[0028] The thrust force required to enable the carriage 3 to move is determined by the shape and profile of the teeth 2a, the shape of the locking member 4 and by the spring constancy of the springs 5.

[0029] Advantageously, the locking member 4 is provided to be cylindrical and pivotable along its longitudinal axis. This allows the locking member to pivot during the shortening movement in the direction D2 and guarantees minimal wear of the teeth of the racks 2 over time.

[0030] It is obvious that the present invention is subject to numerous variations as to its implementation. Although a non-limiting embodiment has been described by way of example, it is understood that it is not conceivable to exhaustively identify all possible variations. It is of course possible to replace a means described by an equivalent means without departing from the scope of the present invention. All these modifications are part of the common knowledge of a person skilled in the art in the field of bracelets.

Claims

1. Device (1) for adjusting the useful length of a bracelet comprising a cover (6) to which a first end (20a) of a bracelet is fixed and comprising at least two side walls (6a) extending in the longitudinal axis of the bracelet, two lateral racks (2) comprising at least two teeth (2a), the racks being integral with the side walls (6a) of the cover (6) and a carriage (3) configured to be made integral with the second end (20b) of the bracelet and capable of moving relative to the lateral racks (2), the carriage (3) comprising a locking element (4) configured to cooperate with the teeth (2a) of the lateral racks (2) to ensure the maintenance of the carriage (3) in a predefined position relative to the racks (2), the locking member (4) being assembled to a press button (8) of the carriage (3) in such a way that the locking member (4) is movable, with reference to the carriage (3),between at least a first, locking position, in which it cooperates with the teeth (2a) of the racks (2), and a second, adjustment position, in which it is out of reach of the teeth (2a) of the racks (2) to allow relative movement between the carriage (3) and the racks (2), the carriage (3) comprising at least one elastic member (5) acting on the push button (8) and tending to move the locking member (4) towards the bottom of the notches (2b) formed between the teeth (2a) of the racks (2), thus blocking the locking member (4) in the notches (2b), , characterized in thatthe profile of the teeth (2a) of the racks (2) is configured such that when a determined pushing force is exerted by a user on the carriage (3) or on the bracelet connected to the carriage (3) in a longitudinal direction from the second end (20b) towards the first end (20a), the force is transmitted to the locking member (4) so as to disengage the locking member (4) from the teeth (2a) of the racks (2) and to cause a movement of the carriage (3) in the longitudinal direction resulting in the shortening of the useful length of the bracelet.

2. Device (1) according to claim 1 in which the carriage (3) is configured to be made integral with the last link of the second end (20b) of the bracelet.

3. Device (1) according to one of claims 1 or 2, characterized in thatthe thrust force required to enable the carriage (3) to move is determined at least in part by the profile and / or shape of the locking member (4) and the notches (2b) and / or by the spring constant of the elastic member (5).

4. Device (1) according to one of the preceding claims, in which, seen in profile, the teeth (2a) comprise a first flank (2a1) and a second flank (2a2), the first flank being oriented essentially perpendicular to the longitudinal axis of the bracelet and the second flank (2a2) forming an angle (A) with the longitudinal axis of the bracelet smaller than 90°, advantageously between 25° and 65°, even more advantageously between 35° and 55°, so that the second flank (2a2) is inclined towards the first end (20a) of the bracelet.

5. Device (1) according to one of the preceding claims, the device (1) being arranged to allow the length to be shortened when the clasp is closed and the bracelet is worn by a user.

6. Device (1) according to one of the preceding claims, the press button (8) comprising a guide pin (8a) arranged to cooperate with notches in the side walls of the carriage (3).

7. Device (1) according to one of the preceding claims, in which the side walls of the carriage (3) comprise a cantilever (3c) arranged to cooperate with the upper edges of the racks (2) so that the carriage (3) can slide on these edges.

8. Device (1) according to one of the preceding claims, wherein the width of the carriage (3) essentially corresponds to the distance between the racks (2).

9. Device (1) according to one of the preceding claims, wherein the racks (2) are directly produced in the side walls (6a) of the cover (6).

10. Device (1) according to one of claims 1 to 8, in which the racks (2) are made integral with the cover (6) by means of pins welded to the cover (6) or by means of screws.

11. Device (1) according to one of the preceding claims, in which the locking member (4) is arranged cylindrical and pivotable around its longitudinal axis.

12. Clasp for bracelet comprising a device for adjusting the length of the bracelet according to one of the preceding claims.

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