CH718703A2 - Wristband attachment device. - Google Patents

Abstract

A bracelet attachment system comprising a spring bar (20) with two coaxial pivots (26, 27), one of which slides relative to a cylindrical body (28). The bar has a groove (25) that can accommodate a removable actuation button. When the bar is mounted in a last bracelet strand has an eyelet on the inside face allowing the insertion of the button. In this way the bracelet can be detached and changed without tools, and the strip (20) is held in position by the button.

Description

Technical area

The present invention relates to the field of watchmaking and, more particularly, to a system for attaching a watch strap to a watch or to a strap clasp or buckle.

State of the art

[0002] A large number of systems are known from the state of the art for attaching a bracelet to a watch, to a clasp or to a bracelet buckle. Some of them allow assembly and disassembly without using a tool, which is particularly advantageous when the bracelets are interchangeable by the user of the watch who can, for example, change the style or color of the bracelet according to his will, without complicated manipulations and without the risk of damaging or scratching the watch by the clumsy use of a tool.

[0003] For example, document US 2014250637 describes a spring bar comprising two coaxial pivots which engage, pushed by an internal spring, in openings made in the opposite internal faces of two horns, as well as a lug making it possible to push against the spring, temporarily reducing the length of the clip so that it can be removed from the openings. This simple solution, however, presents the risk that the ergot clings to jewelry or clothing and that untimely retraction ensues. The ergot is also very small and must be pushed with a fingernail, which can be uncomfortable.

[0004] Another disadvantage of conventional fastening systems is that their hooking power is dependent on a very exact dimensioning of the pivots which must correspond to the dimensions of the box or the loop with which they are intended to be attached. interact. Manufacturers are then obliged to provide and match a large number of bars with pivots of different diameters and must respect very strict tolerances.

Brief summary of the invention

[0005] An object of the present invention is to provide a fastening system that can be used to attach a bracelet to a watch, but also to a piece of jewelry or to another accessory, free from the limitations of known devices.

[0006] According to the invention, these objects are achieved by means of the subject of the appended claims, and particularly by a strap attachment system for connecting a watch strap to a timepiece, comprising a bar with in first pivot and a second pivot arranged to take place between two opposite surfaces of said case or of said clasp or of said buckle, said surfaces comprising concavities or protuberances configured to cooperate with protuberances or housings of complementary shape on the pivots thus fixing the bar between the two opposite surfaces by the action of a spring, characterized by a housing and by a button housed in the housing, the bar being able to be released and moved away from the opposite surfaces by an external force applied to the button which, acting against an elastic force of the spring, causes the first pivot to slide towards the second pivot.

[0007] The dependent claims relate to useful and advantageous, but not essential, features of the invention; for example the fact that the timepiece is a watch case or a bracelet clasp or a bracelet buckle, for example a watch case with two lugs on which the two opposite surfaces are located.

[0008] Advantageously, the bar may have a rod sliding in an assembly body, a first pivot united with the rod and a second pivot united with the assembly body, the groove being formed in the rod, the assembly body comprising an opening vis-à-vis the groove allowing the button to be housed in the groove. In this way, the strip of the invention is in the form of an unremovable assembly, because the assembly body is stamped so as to prevent the stem and the spring which are inside from coming out, while allowing the sliding of the rod. This embodiment can advantageously be housed in a transverse hole at one end of a bracelet strand, the pivots protruding from both sides. In this case, the bracelet has an eyelet through which the button can be passed to fix it by pressing the button in the groove. One thus obtains a bracelet strand which can be attached and detached easily without tools by acting with a finger on the head of the button, which remains accessible thanks to the eyelet.

We can consider several systems to fix the button in the groove. In a preferred embodiment, the button is connected to the pivot by an irreversible mechanical connection. According to the variant shown in the figures, the groove has a shoulder and the button comprises a split rod that can be engaged in the groove and two attachment hooks configured to interact with the shoulder so that the button can be clipped into the groove or released of the groove without tools by simple pressure. Preferably, the groove crosses the bar or the rod to simplify the execution. The button can have a head with a rough, grooved or notched surface, on which one can easily operate with a finger. The texture allows the button to be felt by touch when pressed with the tip of a finger and generates friction which greatly aids actuation. This "tactile" mode of operation is an important advantage of this invention compared to known solutions that are operated with a fingernail.

In the examples presented, the pivots are terminated at the ends by studs of essentially cylindrical or conical shape configured to engage in also cylindrical housings formed in the opposite surfaces, but the invention also includes the so-called strips "Inverted" in which the pivots carry at the ends cylindrical housings configured to accommodate studs on the opposite parallel surfaces.

[0011] The disclosed examples and embodiments illustrate a straight bar with aligned coaxial pivots intended to engage between two substantially parallel opposite surfaces, which is the most common arrangement in watchmaking. The invention, however, is not limited to this variant and also includes curved strips whose profile is supposed to match the contour of the caseband. In these embodiments, the pivots are not strictly parallel, and the surfaces between which engage will be slightly divergent. The rod, suitably shortened, slides in an internal straight chamber which occupies only part of the assembly body.

Another inventive solution is a bracelet attachment device arranged to connect a watch bracelet to a timepiece, comprising a bar with a first pivot and a second pivot configured to take place between two opposite surfaces of the said timepiece, said opposite surfaces comprising concavities configured to cooperate with the pivots thus fixing the bar between the two opposed surfaces by the action of a spring, the device being characterized in that the pivots are conical. This attachment device can be advantageously combined with a watch case with two lugs carrying misaligned concavities to accommodate the pivots. The angle at the top of the conical pivots will be chosen according to the use and the geometry of the lugs, but its choice is not particularly critical. Angles between 10° and 20° have given very favorable results in the majority of cases.

[0013] This solution may comprise a housing and a button secured in the housing, the bar being able to be released and moved away from the opposite surfaces by an external force applied to the button which, acting against an elastic force of the spring, causes the first pivot to slide towards the second pivot. Preferably the button and housing are configured to snap together without tools. As above, the timepiece may be a watch case or a bracelet clasp or a bracelet buckle.

[0014] In the same inventive solution, the strip may include a sliding rod in an assembly body, the second pivot being joined to the rod and the first pivot to the assembly body, the groove will then be formed in the rod and the assembly body will have an opening vis-à-vis the groove allowing the button to be housed in the housing. Optionally, the groove can pass through the strip or the rod.

Brief description of figures

[0015] Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which: sectional. • Figures 2 and 3 show an element (the rod) of the bar of Figure 1 side view and in perspective. • Figure 4 shows a rolled assembly body used in the invention. • Figures 5A-5D and 6 illustrate a possible execution of a removable button cooperating with the strip of the previous figures • Figures 7 and 8 show a watch strap attached to a watch by the fastening system of the invention. • Figure 9 illustrates a variant with conical pivots.

Example(s) of embodiment of the invention

[0016] Figure 1 shows a bar 20 according to one embodiment of the invention, partially in section. The bar 20 has an elongated body of essentially cylindrical shape and comprises a first pivot or cylindrical stud 26 at one end, and a second pivot or stud 27 at the opposite end. The pivots are coaxial and, conventionally, the pivot 27 can slide inside the bar 20 so as to be able to attach and detach the bar 20 between two opposite surfaces 51, 52 of a timepiece which have openings 56, 57 to accommodate the pivots.

To simplify the description, all the examples presented here will relate to this type of bar, in which the pivots end in studs provided to engage in openings of complementary shape of the surfaces51,52. This is not the only configuration envisaged in the invention. The invention includes, for example, so-called “inverted” bars which have coaxial openings at the ends of the pivots and complementary pads in the timepiece.

The barrette20de the invention can be used, as discussed below, to attach a strap to a watch, clasp or buckle. The invention is not limited to watchmaking either, but also applies to all related fields in which bracelets or straps must be attached to various parts, for example to the fields of jewelry, leather goods and shoemaking.

In the example shown, the first pivot26est joined to the closed base of a metal assembly body28, inside which can slide the rod21qui carries at one end the second pivot27qui engages in the opening56. The open end of the assembly body 28 has a stamped lip limiting the movement of the rod 21 which is free to slide inwards without being able to come out. Only the second pivot27 goes beyond the assembly body and engages in the opening57.

Inside the assembly body 28, the rod 21 comprises a part of reduced diameter 29 around which is a spring 40 which rests on the internal base of the assembly body 28 and pushes the rod 21 and the pivot 27 to the left. Notably, the stem 21 includes a groove 25 in which a button can be accommodated, as will be seen below. The assembly body 28 also includes an opening 80 vis-à-vis the groove 25 (visible in FIG. 4) allowing the insertion of the button.

The shape of the groove25illustré in the figures is only one of several possible variants of opening that can accommodate a button that are possible within the scope of the invention. The shape of the opening 25 will be determined with that of the button, as will be seen later, so as to give an assembly which can be assembled properly and solidly. Preferably, the opening 25 and the button 30 are configured so as to be able to be secured together by an irreversible mechanical connection. By irreversible is meant here a connection which can be obtained easily, for example by simple pressure, but which is difficult to disassemble, or can be dismantled only with special tools, or is completely unremovable unless parts are cut or broken.

Figures 2 and 3 show the insulated rod 21. You can see the pivot27, the groove25 with the shoulder 28 and the section of reduced diameter29. Advantageously, this structure can be obtained by conventional machining techniques, for example by turning a metal blank in brass, steel, stainless steel, or another suitable material. Other production techniques are however possible. The assembly of the strip 20 is made by stamping and crimping the assembly body 28 on the rod 21, with the prior insertion of the spring 40 inside.

[0023] Figure 4 shows a preferred embodiment of the assembly body 28 suitable for flexible bracelets, for example leather, fabric or rubber. As already mentioned, this element has a part of cylindrical shape in which the rod 21 can slide, and ends in a pivot 26 which is cylindrical or conical. The opening 80 which allows the assembly between the button 30 and the rod 21 is preferably surrounded by a projecting lip 82 which engages in a similarly shaped eyelet in a bracelet strand, as can be seen in Figures 7 and 8. When the bar of the invention is used in a leather or fabric bracelet, the lip 82 prevents contamination of the internal cavity or the external surface by the adhesive used in the assembly. In the construction of rubber wristbands, the lip 82 is a sealing barrier to confine the rubber prior to vulcanization or crosslinking.

Remarkably, the assembly body 20 has a substantially flat tongue 23 which fits into the plane of the bracelet. The flat tongue 23 increases the solidity of the assembly between the bar and the bracelet and defines the angle α between the plane of the bracelet and the axis of the opening 80, and consequently of the button 30. Preferably this angle α is less than a right angle and its value is chosen to prevent any contact between button 30 and the bottom of the watch case.

The assembly body 28 lends itself to manufacture by deformation of a flat metal part, by bending, rolling and stamping operations. This technique advantageously makes it possible to produce light and resistant assembly bodies, at a contained cost. The material used for the manufacture of the assembly body 28 can be a stainless steel.

Another unillustrated variant of the invention is a fastening device for a watch strap with articulated metal links. In this embodiment, the assembly body may be a machined part carrying a pivot and enclosing inside the spring 41 and the rod 21. The assembly body will provide an opening for the insertion of the button 30, in the same way than in the examples shown; its shape, the material used and the finish of its surface will be designed to integrate harmoniously with the links of the bracelet.

In a later variant of the invention, the attachment device does not have the shape of a straight bar but is curved, for example to match the profile of a round watch case. The assembly body will then have a curved shape and the two pivots will be slightly divergent rather than coaxial and aligned. The assembly body encloses an essentially cylindrical cavity in which can slide a rod carrying a pivot, as in the examples already illustrated. The rod, suitably sized, may have a straight stroke inside the curved assembly body.

[0028] Figures 5A-5C and 6 show one possible embodiment of a button 30 configured to engage mechanically and irreversibly with the rod 21. It consists of a head31and a slotted stem35configured for insertion into the groove25. The split shank has two hooks 37 which engage with a correspondingly sized shoulder 28 in the shank 21, stabilizing the position of the button in the groove. The head 31 protrudes outside the bar and has a rough, notched or grooved surface to allow actuation with a finger. The button can also be made by machining or by any suitable implementation technique, for example by stamping a precious metal blank. The button 30 could also be made of a technical polymer or a composite.

[0029] The invention allows several variations of the shape of the split rod 35 which are mechanically compatible with the housing 25 and, preferably, allows a stable assembly without tools of the button in the housing. In the example illustrated the housing 25 is a rounded groove, and the rod 35 is a tenon whose section matches that of the groove. It is possible to conceive variants in which the opening 25 has a different shape, for example cylindrical or rectangular, and the rod 35 the corresponding male shape. It would also be possible, without departing from the scope of the invention, to arrange on the stem 21 several openings and several studs of compatible shape on the button. For example, two cylindrical holes could be made in the rod 21 which interact with two parallel cylindrical studs of the button 30.

The shape of the tête31n is not limited to that of the example shown and could assume other shapes, for example round or square, provided that its dimensions allow actuation with a finger. The accessible surface of the head 31 has a texture which makes it possible to feel the button with a finger and to operate it easily. Ideally, the texture of the button head is aggressive enough to generate the friction required for 'touch' actuation without however snagging on clothing or jewelry. In the figures, this texture is achieved by parallel grooves of shallow depth, but many other executions are possible.

[0031] Lesfigures 7et8montrent a possible use of the strip of the invention to attach a watch strap. The bracelet strand 60 has, conventionally, an essentially flat shape with a through hole 68 at one end capable of receiving the bar 20. The strand 60 is made of a flexible material, for example leather, fabric or rubber, or by an assembly of rigid or metal links. The strand 60 is configured to be fixed between two horns 50 in which openings 56, 57 are made for the pins 26, 27 of the bar 20. The bracelet strand 60 has an elongated eyelet 62 opposite the groove 25, allowing the insertion of the button 30 in the strip when it is housed in the hole 68. Thanks to this arrangement, the bar 20 can be attached and detached easily and without tools by acting with a finger on the button 31. It goes without saying that the same arrangement could be used at the other end of the strand to attach a buckle or a bracelet clasp.

[0032] Advantageously, this invention provides bracelets that can be assembled and disassembled without tools and have a neat aesthetic, because the only visible part of the fastening system is the tête31du bouton30. This system avoids all the snagging hazards that come with conventional spigot systems, and is easier to handle because the button can be operated with the tip of a finger, rather than a fingernail. This product can also be easily personalized and declined in several variants to match various watches and accessories, by simply modifying the button30.

[0033] The figure 9 illustrates a variant of the invention with two conical pivots66,67, with a relatively acute vertex angle. This arrangement is advantageous because it is compatible with watches with variability in the dimension of the cavities56,57. It is common, for example, for the opposing housings 56, 57 in the horns 50 of the watches to be slightly offset to simplify the drilling operations. This misalignment reduces the gripping power of the usual cylindrical pivots, because the contact between pivot and housing becomes punctual. Very tight tolerances must be used to achieve the desired tensile and torsional strength. The contact between the conical pivots66,67and the housings56,57, on the other hand, substantially approaches a generatrix of the conical surface.

The angle of the cone will preferably be chosen according to the angle between the axes of the housings 56, 57, for example an angle between 10° and 20°. The inventors have however found through tests that the gripping power of the conical pivots 66, 67 is relatively insensitive to sizing faults. In contrast, tapered pivots66,67 retain their effectiveness even in the presence of diameter and alignment errors that would cause conventional cylindrical pivots to fail.

Reference numbers used in the figures

[0035] 20bar21rod23tongue25groove261st pivot272nd pivot28assembly body29reduced diameter section30button31head of button35split rod37hooks40spring50horns51surface52surface56housing57housing60bracelet strand62eyelet661st tapered pivot672nd tapered pivot68through hole80opening82chimney

Claims (13)

1. Bracelet attachment device arranged to connect a watch bracelet to a timepiece, comprising a bar (20) with a first pivot (26) and a second pivot (27) configured to take place between two opposite surfaces (51, 52) of said timepiece, said opposite surfaces comprising concavities (56, 57) or protuberances configured to cooperate with protuberances or concavities of complementary shape on the pivots (26, 27) thus fixing the bar (20) between the two opposite surfaces by the action of a spring (40), the device being characterized by a housing (25) and by a button (30) secured in the housing (25), the bar being able to be released and moved away from the opposite surfaces by an external force applied to the button which, acting against an elastic force of the spring (40) causes the first pivot to slide towards the second pivot. 2. Bracelet attachment device according to one of the preceding claims, wherein said pivots (26, 27) are coaxial and said opposite surfaces (51, 52) are parallel. 3. Bracelet attachment device according to the preceding claim, wherein the button (30) and the housing (25) are configured to snap into each other without tools. 4. Bracelet fastening device according to the preceding claim, wherein the housing (25) is a groove having a shoulder (28) and the button (30) comprises a split rod (35) engageable in the groove (25) and two attachment hooks (37) configured to interact with the shoulder (28) so that the button can be snapped into the groove (25) without tools. 5. Bracelet attachment device according to one of claims 2 or 3, wherein the engagement of the button (30) in the groove (25) is irreversible. 6. Bracelet fastening device according to one of the preceding claims, in which the timepiece is a watch case or a bracelet clasp or a bracelet buckle. 7. Wristband fastening device according to one of the preceding claims, wherein the strip comprises a rod (21) sliding in an assembly body (28), the second pivot (27) being joined to the rod (21 ) and the first pivot (26) being joined to the assembly body, the groove (25) being made in the rod (21), the assembly body (27) having an opening facing the groove (25 ) for accommodating the button (30) in the housing (25). 8. Strap fastening device according to the preceding claim, wherein the groove (25) passes through the strip (20) or the rod (21). 9. Bracelet fastening device according to one of claims 7 or 8, wherein the assembly body comprises a cylindrical section enclosing the rod (21) and a flat tongue (23). 10. Bracelet fastening device according to one of the preceding claims, the button comprising a head (31) with a rough, grooved or notched surface. 11. Bracelet fastening device according to one of the preceding claims, in which the pivots are terminated at the ends by studs of essentially cylindrical or conical shape configured to engage in concavities (56, 57) formed in the surfaces opposites. 12. Bracelet fastening device according to one of claims 1 to 7, in which the pivots are terminated at the ends by cylindrical concavities configured to accommodate essentially cylindrical studs on the opposite surfaces. 13. Bracelet attachment device according to one of the preceding claims, attachable to a watch case with two horns (50) on which are the two opposite surfaces (51, 52), the bar (20) and the spring (40) fit into a transverse hole at one end of a bracelet strand (60) the pivots (26, 27) protruding from both sides to engage in concavities (56, 57) made in the horns ( 50), the bracelet having an eyelet (37) allowing the button (30) to be fixed by pressure in the groove (25), the rod (35) of the button (30) passing through the eyelet (37) to engage in the groove (25), the head (31) of the button (30) being accessible with a finger to receive the external force making it possible to release one of the pivots (26, 27) from the respective housing and detach the bracelet strand (60 ).