EP0820241A1

EP0820241A1 - Strap clasp

Info

Publication number: EP0820241A1
Application number: EP96937968A
Authority: EP
Inventors: Jacques Hubert Gay; Luigi Ferrario
Original assignee: Gay Freres Vente et Exportation SA; Gay Freres SA
Current assignee: Gay Freres Vente et Exportation SA; Gay Freres SA
Priority date: 1996-02-12
Filing date: 1996-11-27
Publication date: 1998-01-28
Also published as: US5829104A; JPH11503957A; AU7559396A; WO1997029660A1

Abstract

A clasp (1) for a strap (2) having two blades (6, 8) pivotably connected at one end via a common hinge (10). The clasp has a cover (3) and a base (9) releasably arranged around a common rod (11) guided by a transverse arm (6.4) that is solidly connected to the first blade (6). A first strap portion (2.1) is fastened to the second blade (8), and a projection (4) on the base (9) is used to attach a second strap portion (2.2). The connection is strengthened by folding the cover (3) down over the projection (4), and the folded cover (3) and the base (9) are pivotable together relative to the first blade (6) so that the clasp (1) may be opened and the strap (2) removed without undoing said connection.

Description

CLASP FOR BRACELET

The invention relates to closures which are specially used to provide a clasp closure for a bracelet according to the claims.

Closures are used in many different technical fields. They are for example used in security engineering (doors, windows, etc.), or in watchmaking (wristwatches). By way of example, the wristwatch wristwatches open and close using closing means known as a folding and snap-fastening clasp.

Such a bracelet clasp is usually provided with a bar and a stud for fixing the strands of the bracelet and it is provided with folding blades to be able to remove the wristwatch with closed bracelet. Said bar allows permanent attachment of a first strand of the bracelet to the clasp and said stud allows the temporary attachment of another strand of the bracelet to the clasp by introducing the stud into a hole in said free strand. The bar and the stud are attached to different blades, articulated with respect to each other through a common hinge, allowing an enlargement of the diameter of the bracelet by separating and pivoting the two blades so as to be able to remove the bracelet without undoing the temporary fixing of the strand. Thereafter, the discussion will be limited to the advantages and disadvantages of a foldable and snap-fastening closure of a wristwatch. Disadvantages will be presented which are linked to a stable fixing of the free strand to the nipple of a clasp blade, to a solid construction of the elements of the clasp and to the adjustment of the length of the bracelet which is safe and easy.

The attachment of the free end is unreliable when the nipple used is articulated with respect to a support blade and when this mechanism has modest dimensions that can be deformed and damaged under the effect of the tensile and torsional forces picked up by the bracelet. Opening the clasp and adjusting the length of the bracelet is carried out in several stages and requires a large number of elements on the one hand to unlock the clasp blades and on the other hand to undo the fixing of the free strand of the bracelet.

A solution allowing an easy fixing of the free strand of the bracelet is described by the Swiss patent N ° 661'186 by incorporating a stud in a massive cover articulated with respect to a first support blade allowing the fixing of a free strand in pivoting the cover towards said support blade and inserting the stud in a hole in said strand. The locking of the clasp blades is obtained by notching a second stud arranged on said first support blade in an opening of a second clasp blade.

This construction has the disadvantage that the tensile and torsional forces acting on the bracelet are captured by the hinge of the cover, which can deform and damage it, resulting in rapid wear. A solution making it possible to remove the bracelet without risk of undoing the fixing of the free bracelet strand is described by European patent N ° 607,726 having a stud arranged on a base plate connected in a removable manner with respect to a first blade, allowing fixing the free bracelet strand. A cover is mounted on said first blade and is articulated with respect to said blade and with respect to said base plate, allowing pivoting towards the base plate and notching with said base plate. Another strand bra¬ celet is permanently attached to a second blade of the clasp. The locking of the two blades is obtained by engaging two openers of the two blades on two rods mounted on a third clasp blade.

This construction has the disadvantage that the tensile and torsional forces acting on the bracelet are captured by the hinge of the cover and the base plate which can deform and damage it, resulting in rapid wear.

This is why the objective of the present invention is to provide a solution to these problems by creating a clasp closure, for general application, for example for a wristwatch, of a particularly compact construction, requiring a minimum number of elements for locking the clasp and adjusting the length of the bracelet, while being compatible with known and proven manufacturing techniques.

This object is achieved by the invention defined by the claims. The clasp according to the invention is the result of a detailed study of the mechanisms governing the fixing of the bracelet strands and the locking of the clasp blades. In particular, the invention relates to the tensile and torsional forces picked up by said bracelet. Said forces are directed towards solid and stable elements, making it possible to avoid any deformation and damage to the sensitive elements of the clasp, in particular means for locking the clasp and the hinge of the cover.

Said clasp comprises two blades articulated one inside the other by one of their ends, so that the two blades can be folded down, one included in the other. It is possible to perform a first locking of the blades by notching a pin of the blade inside a transverse branch of the outer blade.

- A bar mounted on the outer blade allows permanent attachment of a first strand of the bracelet to the clasp. A pin mounted on a base allows the attachment of another strand or free strand of the bracelet.

The base is removably mounted around a rod relative to the inner blade. Said rod is installed inside a transverse branch of the inner blade. The transverse branch has several aligned half-bushings serving as a guide for holding the rod along their axis. At least two half sleeves are spaced from each other, resulting in a small angle of thumping of the rod and serve as a robust and stable pendant to capture the pulling and torsional forces acting on the bracelet through the barb on the base and the base on the transverse branch and the transverse branch on the robust blade, thus avoiding deformation and damage to the more sensitive elements of the clasp. The cover is removably mounted around the rod relative to the inner blade allows a strengthening of the fixing of the free strand to the barb. Advantageously, a central part of the cover folds over the barb.

The cover allows a second locking of the battered blades of the clasp. Advantageously, it is possible that the lateral arms of the cover and the lateral branches of the outer blade are closed by notching.

The cover and the base have no direct connection, avoiding any propagation of tensile and torsional forces picked up by the base towards the cover, which can result in deformation and damage to the hinge of the lid.

The cover and the base of the barb are hinged jointly with respect to the inner blade and they are hinged in an individual manner with respect to one another. Said joint articulation of the cover and the base is effected by means of a friction force of the bracelet, connecting the cover and the base through the bracelet.

By using the clasp according to the invention, it is therefore possible to pivot the cover and the carrier base of the barb jointly with respect to the blades, lifting the second lock and giving access to the unlocking of the blades. The fixing of the free strand by the barb remains reinforced by the cover and is not affected by this joint pivoting, allowing the unlocking of the blades to remove the bracelet without risk of undoing the bracelet. In addition, it is possible to pivot the cover individually relative to the base carrying the barb to lift said reinforcement from the fixation of the free strand and to give access to the barb. The free strand of the bracelet fixed by the barb is released in a separate step, allowing the length of the bracelet to be adjusted quickly and easily by separating the free strand from the barb. In particular, it is possible to adjust the length of the bracelet without removing the bracelet from the arm.

The characteristics of the invention will be better understood on reading the following description and with reference to the accompanying drawings, in which:

- Figures la, lb and are a schematic view showing a preferred embodiment of a clasp according to the invention.

- Figure 2 is a perspective and exploding view of said preferred embodiment of a clasp according to Figures la, lb and.

- Figure 3 is a schematic of said preferred embodiment of a clasp according to Figures la, lb, le and 2, showing how the tensile and torsional forces are captured.

FIGS. 1a, 1b and 1c are a schematic view showing the attachment of the strands of a bracelet to a preferred embodiment of a clasp according to the invention, as well as the mechanism for locking the blades of said clasp and the mechanism for strengthening said fixing and the two possible locks. Figure 2 is a perspective and exploding view of said preferred mode of execution of a clasp according to Figures la, lb and. The clasp 1 comprises two blades 6,8 articulated with respect to each other by one of their ends through a common hinge 10, so as to be able to pivot. According to Figure 2, said ends of the two blades 6,8 are pierced with holes aligned with each other serving as a guide sleeve for main¬ hold along their axis a rod 10 'of the hinge 10. The bracelet and the elements visible from the closure of the clasp are preferably metallic, they can be made by stainless steel and / or gold constructions.

A first blade or inner blade 6 is arranged inside a second blade or outer blade 8. The outer blade 8 comprises a notch 8.1 of shape and dimensions corresponding to those of the inner blade 6, so that the last either partially or entirely included in this notch 8.1 when the clasp is in the closed position. The two longitudinal branches 8.2, 8.3 of the outer blade 8 have support surfaces 8.20, 8.30 to support corresponding surfaces of the inner blade 6 when the clasp is closed. It is possible to carry out a first locking of the blades by notching a pin 6.5 of the inner blade 6 to a transverse branch 8.4 of the outer blade 8. As the two blades 6,8 directly capture the tensile and torsional forces acting on the bracelet 2, this reciprocal engagement of the two blades 6,8 one inside the other results in a closed clasp 1 particularly reliable by its stability and rigidity.

A bar 5.5 ′ mounted on the outer blade 8 allows permanent attachment of a first strand 2.1 of the bracelet 2 to the clasp 1. It consists of two detachable side parts 5.5 ′ which can, for example, be screwed separately into tapped holes in a central part 50, securely attached with a transverse branch 8.4 of the outer blade 8. This bar 5.5 'allows particularly easy and rapid assembly of the first strand bra¬ celet 2.1 by fixing said first strand 2.1 using a slot 2.Î0 against the central part 50 and by screwing the two lateral parts 5.5 'through said first strand 2.1 in tapped holes of a central portion 50. Those skilled in the art, knowing the present invention, can achieve other embodiments of this type of bar using other means and other techniques for connecting the lateral and central parts and the first strand with a clasp blade.

The barb 4 mounted on the inner blade 6 allows the attachment of another free strand 22 of the bracelet 2. It is mounted on a base 9, attached with the transverse branch 6.4 of the inner blade 6. The barb 4 and the base 9 are fixed, preferably, by welding, by screwing or even by milling in one piece. The transverse branch 6.4 and the inner blade 6 are preferably fixed by welding. Other connection techniques are of course possible. Those skilled in the art, knowing the present invention, can of course make other fixing means for other basic materials, for example thermofusion for synthetic hot-melt materials, etc.

The bar 5.5 'and the barb 4 are mounted on the other ends of the two blades 6,8, that is to say being located on the opposite side of the arrangement of the hinge 10. The bar 5 , 5 'and the barb 4 are fixed with the two blades 6,8 through a central part 50 and a base 9. These parts 50,9 are intended to capture the tensile and torsional forces exerted on the bracelet 2 and acting through the strands 2.1, 2.2.2 of the bracelet 2 on the bar 5.5 'and the barb 4 of the clasp 1. These parts 50, 9 are of massive construction, having a certain thickness and rigidity. The cover 3 and the base 9 of the barb 4 are pivotally mounted and attached to the same transverse branch 6.4 of the inner blade 6. A rod 11 is installed inside the transverse branch 6.4 of the inner blade 6. Preferably, the transverse branch 6.4 having at least two half bushings 6.4 ', 6.4 "aligned with one another serving as a guide bushing to hold said rod 11 along their axis. The half bushings 6.4', 6.4" are spaced from each other, is that reduces the backlash of the rod 11. Thus, the half sockets 6.4 ', 6.4 "serve as a pendant to the rod 11 of the base 9, which allows to capture the tensile and torsional forces exerted from the brace-bret 22 on the barb 4, and then from the base 9 on the rod 11, without deforming and damaging other more sensitive elements of the clasp 1. This protection of the sensitive elements relates in particular to the locking means of the clasp and the hinge d u cover 3. For this purpose, the at least two half-sockets 6.4 ′, 6.4 "are arranged so as to prevent any propagation of the forces picked up by the base 9 towards the cover 3. The base 9 is attached to a central part of the rod 11 and it is set so as to be between the two half sockets 6.4 ′, 6.4 ", allowing the base 9 to transmit the forces captured to the rod 11 while generating a minimum moment. The cover 3 is attacked through two lateral arms 3.2, 3, 3 at the ends of the rod 11, that the cover 3 and the base 9 are separated by the two half sockets 6.4 ′, 6.4 ", allowing the base 9 to transmit the captured forces to the rod 11 and by preventing them from affecting the cover 3. The elastic flexion curve (deformation) of the rod 11 is limited in such a way by the two half sockets 6.4 ′, 6.4 ", that there is no danger of deformation and damage. Said particular construction according to the invention is shown in detail in FIG. 3. Any force F of traction and torsion acting on the rod 11 is captured by the half sockets 6.4 ′, 6.4 ", there is no components of said forces acting through the rod 11 on the cover 3. Unlike the fer¬ moir described in European Patent No. 60T726, the rod rests in two half sockets distant from each other, serving as a stable guide sleeve . The transmission of tensile and tension forces picked up by the barb through the rod towards the cover is not possible, the cover is separated from the lines of forces picked up by the bracelet. According to European Patent No. 607,726, said forces picked up by the bracelet act on the rod and under the effect of the elastic bending curve of the rod directly on the relatively sensitive hinge of the cover.

The cover 3 and the base 9 are not in direct connection. The base 9, being located inside the cover 3 and inside a notch 6.1 of the inner blade 6, is mounted between the two half sockets 6.4 ', 6.4 ". The two half sockets 6.4' , 6.4 "are arranged at the edges of the inner blade 6. The base 9 is attached to a central part of the rod 11 and between the two half sockets 6.4 ', 6.4", allowing pivoting at any angle C. The neck - ring 3 is mounted outside the two half sockets 6.4 ', 6.4 ". The cover 3 is attached through two lateral arms 32, 3, 3 to the ends of said rod 11, allowing pivoting by an angle C. Unlike the clasp described in European patent N ° 60T726, where the cover and the base plate are connected by notching, the cover does not have a direct and fixed connection with the base, separating the cover from the lines of force picked up by the bracelet, so that said tensile and torsional forces cannot damage the charm of the cover .

Advantageously, the cover 3 and the base 9 can perform a joint pivoting under the effect of a friction force transmitted by the bracelet 2. During such a joint pivoting, the cover 3 and the base 9 do not change their position reciprocal, allowing the bracelet 2 to be opened and closed without the risk of undoing the fixing of the free strand 22 by the barb 5. In the context of this invention, numerous embodiments of such a joint pivoting are possible. By way of example, the free strand 22 having a certain stiffness and by being fixed by the barb 5, exerts a slight friction force on the internal walls of the cover 3. A similar friction force can be generated by pressing the cover 3 against the free strand 22 during the opening of the cover 3. Unlike the clasp described in European Patent No. 607,726, the joint pivoting is carried out without requiring a direct connection between a cover and a base plate. Said clasp comprises a cover and a base fixed by notching. Such a fixed connection by notching the cover with the base represents a complication, requiring additional elements. The solution according to the invention fulfills the same function and it constitutes a simplification of the construction of the clasp. Those skilled in the art, knowing the present invention, can achieve other embodiments of such joint pivoting by using other means and other techniques.

The cover 3 is capable of controlling, that is to say of freeing or preventing access to the barb 4 by pivoting relative to the base 9. Likewise, the cover 3 is capable of controlling, that is to say to release or to em¬ catch the unlocking of the blades 63 by pivoting relative to the closed blades 6,8. Advantageously, the cover 3 and the base 9 pivot jointly to perform a second unlocking and / or to free access to the first unlocking of the blades 6,8.

To open the closed clasp 1, it suffices to place for example a fingernail on the tab 3.1 and to lift the cover 3. Advantageously, the cover 3 and the base 9 perform a joint pivoting. Under the effect of an opening force, the cover 3 is raised and the elastic lateral arms 3, 2, 3 of the cover 3 regain their initial structure and lose the slight deformation when snapping onto the outer blade 8. To separate the cover 3 from the base 9, it suffices to continue the pivoting at any angle C. It is for example possible, to delimit the pivoting of the base 9 at a lower angle relative to the cover 3. This separation angle can be fixed at 30 ° or 40 °.

Thus it is possible to adjust the length of the bracelet 2. Referring to the views according to Figures la, lb and 2, showing a clasp 1 with cover 3 lifted and separated from the base 9, the second bracelet strand 22 is insertable into a space 7 delimited on one side by two rods 11,12 of the cover 3, respectively by a transverse branch 6.4 of the first blade 6, and on the other side by a central portion of said cover 3. Said second bracelet strand 22 inserted is guided by the two rods 11,12 in the space 7 allowing a controlled fixation and an unlimited adjustment of the length of the free strand 22 by positive engagement of the free strand 22 with the barb 4. Preferably, the second bracelet strand 22 is fixed by insertion of the barb 4 into one of the holes of the free strand 22, thus preventing longitudinal movement of the bracelet 2. The barb 4 has a curved end so that the free strand 22 can be maintained by friction. Advantageously, a central part of the cover 3 is mé¬ swam to be able to rest on said curved end of the barb 4.

To close the open clasp 1, it suffices to close the cover 3 on the ar¬ dillon 4 and push the cover 3 and the base 9 in the direction of the two blades 63 until one of the two or both systems notches snap into place. It is possible to carry out a first locking of the blades by notching a pin 6.5 of the inner blade 6 to a transverse branch 8.4 of the outer blade 8. It is possible to carry out a second locking of the blades 6,8 by engagement with notch of the lateral arms 3233 of the cover 3 with external parts of the two longitudinal branches 8.2,8.3 of the external blade 8. Under the effect of a locking force, the lateral arms 3.2,3.3 of the cover 3 are pushed onto the longitudinal branches 8.2, 83 of the outer blade 8. The lateral arms 3.2, 3.3 are provided with a certain elasticity. The reciprocal distance of the two longitudinal branches 8.2, 8.3 is chosen so that the lateral arms 3233 are slightly deformed during latching.

It is understood by itself that the first locking performed by the pin 6.5 of the inner blade 6 and the transverse branch of the outer blade 8 and the second locking effected by the cover 3 of the inner blade 6 and the longitudinal branches 8.2,8.2 of the outer blade 8 are optional. Those skilled in the art, knowing the present invention, can carry out executions of a clasp 1 according to the invention which is closed either only by said first lock or either only by said second lock or by a combination of the first and of the second lock.

Claims

1. Clasp (1) for bracelet (2), comprising a first and a second blade (6,8) articulated relative to each other, allowing an enlargement of the diameter of the bracelet (2) to remove the bracelet ( 2), a first bracelet strand (2.1) anchored to a second blade (8) and a second free bracelet strand (22), characterized in that a pin (4) forming part of a base (9), allows an attachment of the second bracelet strand (22) by positive engagement with the barb, that the base (9) is removable around a rod (11) and that a transverse branch (6.4) is securely attached to the first blade (6) having at least two half bushings (6.4 ', 6.4 ") serving as a guide for the rod (11), making it possible to capture the tensile and torsional forces exerted by the second bracelet strand (22) on the barb ( 4), the base (9) on the rod (11) and the rod (11) on the first blade (6) without deforming and damaging other more sensitive elements of the clasp (1).

2. Clasp (1) according to claim 1, characterized in that the base (9) is attached to a central part of the rod (11) and between two half sockets

(6.4 ', 6.4 "), allowing the base (9) to transmit the captured forces to the rod (11) without being able to deform and damage said rod (11). Clasp (1) according to claim 1, characterized in that a cover (3) is attached through two lateral arms (3233) to the ends of the rod (11), the base (9) being attached to a central part of the rod (11) and that the cover (3) and the base (9) are separated by two half sockets (6.4 ', 6.4 "), allowing the base (9) to transmit the forces picked up to the rod (11 ) and preventing them from affecting the cover (3).

4. Clasp (1) according to claim 1, characterized in that a cover (3) is removable around the rod (11), allowing the reinforcement of said fixing of the second bracelet strand (22) by positive engagement with the barb by folding back on the barb (4).

5. Clasp (1) according to claim 4, characterized in that the barb (4) has a curved end to be able to keep the free strand (22) by friction and that a central part of the cover (3) is mena¬ gée to be able to rest on said curved end of the barb (4).

6. Clasp (1) according to claim 3 or 4, characterized in that the folded neck (3) and the base (9) are connected to each other under the effect of a friction force through the bracelet strand (22), allowing them to be articulated jointly with respect to the first blade (6) and the opening of the clasp (1) in order to remove the bracelet (2) without undoing said fixa ¬ tion.

7. Clasp (1) according to one of claims 3 to 6, characterized in that the second bracelet strand (22) is insertable in a space (7) delimited by two rods (11,12) of the cover (3) and by the transverse branch (6.4) and that said second bracelet strand (22) inserted is guided in the space (7) allowing controlled fixing of the second bracelet strand (22) by the barb (4).

8. Clasp (1) according to claim 1, characterized in that a pin (6.5) is arranged on the first blade (6) and a transverse branch

(8.4) is arranged on the second blade (8), allowing a first ver¬ rusting of the blades (6,8) by notch engagement by folding the first blade (6) on the second blade (8).

9. Clasp (1) according to one of claims 1 to 8, characterized in that the first blade (6) is mounted inside the second blade (8) and that the second blade (8) comprises a notch (8.1 ) of shape and dimensions corresponding to those of the first blade (6), so that the latter is partially or entirely included in this notch

(8.1) when the clasp (1) is in the closed position.

10. Clasp (1) according to one of claims 1 to 9, characterized in that the second blade (8) has two longitudinal branches (82,83) having bearing surfaces (820,830) to support corresponding surfaces of the inner blade (6) when closing the clasp, making this rigid and stable clasp.

11. Clasp (1) according to one of claims 1 to 10, characterized in that a bar (5.5 ') is mounted on a central part (50) securely attached to one end of the second blade (8), achieving anchoring the first bracelet strand (2.1) to the second blade (8), so that the tensile and torsional forces picked up by the bracelet (2) act through the bar¬ rette (5,5 ') on the central part (50) and on the second blade (8).

12. Clasp (1) according to claim 11, characterized in that the bar (5.5 ') consists of two detachable side parts (5.5') which can be screwed separately into tapped holes in the central part (50 ), securely attached with a transverse branch (8.4) of the second blade (8), allowing particularly easy and rapid assembly of the first bracelet strand (2.1) by fixing said first strand (2.1) using a slot (2.10) against the central part (50) and by screwing the two lateral parts

(5,5 ') through said first strand (2.1) in tapped holes in a central part (50).

13. Clasp (1) according to one of claims 1 to 12, characterized in that the cover (3) comprises lateral arms (3233), allowing a second locking of the blades (6,8) by notch engagement of the lateral arms ( 3233) with outer parts of two longitu¬ dinales branches (82,83) of the outer blade (8).

14. Clasp (1) according to claim 13, characterized in that the lateral arms (3233) having a certain elasticity and that the reciprocal distance of the two longitudinal branches (82,83) is chosen so that the lateral arms (3233) are slightly deformed when the cover (3) is snapped onto the outer blade (8).

15. Clasp (1) according to one of claims 8 or 13, characterized in that it closes with said first lock and / or by said second lockil¬ lage.