Patent Application
20180368540
This application claims priority of European patent application No. EP17177805.3 filed Jun. 26, 2017, which is hereby incorporated by reference herein in its entirety.
The present invention relates to a clasp for a wristwatch, as well as a wristband and a wristwatch per se comprising a suchlike clasp.
A plurality of solutions exist for the attachment of the two strands of a wristband around the wrist of its wearer. The first solution is simple and involves providing the extremities of each strand with means of cooperation, for example in the form of a simple buckle and a pin on the one hand cooperating with holes on the other hand. A suchlike solution exhibits the disadvantage that, in the course of opening the means of cooperation, the two strands of the wristband are immediately disassociated and entail a risk of the wristwatch falling.
In order to address this disadvantage, another solution involves the provision of an intermediate element of the clasp type, disposed between the two strands of the wristband, which element remains attached at all times to the extremities of said two strands. A suchlike clasp adopts two configurations: a closed configuration, intended for wearing the watch, in which the wristband and the clasp extend around the periphery of the wrist by exhibiting a total length permitting the wristwatch to be held securely, and an open or deployed configuration, which permits the length of the clasp, and therefore of the wristband, to be increased by moving apart the two extremities of the two strands of the wristband, but without detaching them from the clasp, in order to permit the passage of the hand and the removal of the watch. In this open configuration of the clasp, the two strands of the wristband are not disassociated, which minimizes the risk of the watch falling.
In a solution with a clasp, a first aim is to seek to ensure optimal comfort when wearing the wristband. In order to achieve this, it is advantageous for the clasp to conform as closely as possible to the contour of a wrist, including that of a small wrist, when the clasp is in its closed configuration. In parallel, a second aim is to obtain a large opening surface of the wristband in the deployed configuration of the clasp, in order to facilitate the passage of a hand, adapted for the passage of a hand having large dimensions. The two aforementioned aims may appear to be contradictory, since the blades of a clasp having small dimensions assist in the achievement of the first aim to the detriment of the second aim, which would instead require blades having larger dimensions. One difficulty encountered in the realization of a clasp is accordingly to define the compromise between the need to conform to the wrist of a person wearing a wristwatch in an adequate and comfortable manner and the need to offer a sufficiently large opening for the passage of the wearer's hand, irrespective of the dimensions of the hand and the wearer's wrist.
Document EP1654950 describes by way of example a clasp that is familiar from the prior art. A suchlike clasp is illustrated in
A suchlike solution that is familiar from the prior art meets the requirement for comfort by the two blades 1, 2, which exhibit a substantially identical curve r1, r2 in order for them to be able to overlap one another in the closed configuration, while conforming as closely as possible to the form of a wrist. The first blade is a movable blade 1, which performs a rotation of substantially 180 degrees about its axis of articulation A1 between the two configurations, closed and deployed, of the clasp. The length of the two blades 1, 2 is designed so that they are also able to conform to the form of a small wrist. Finally, a suchlike solution that is familiar from the prior art is advantageous in the sense that it utilizes a user-friendly, intuitive and secure locking device which is particularly effective.
The effect of the limited length of the blades of the clasp is to limit the opening surface offered by the clasp in the deployed configuration, which may impede the passage of a hand, in particular in the case of a large hand. An increase in the length of the blades would not be a satisfactory solution because it could compromise the comfort of the wearer, especially in the case of a small wrist. Furthermore, no universal correlation exists, of course, between the size of the hand and that of the wrist of the person wearing a wristwatch, and no rule exists for optimizing the length of the blades according to the size of the wrist or the size of the hand.
Other solutions that are familiar from the prior art meet the contradictory requirements described above by multiplying the number of blades. However, such solutions have the disadvantages of complicating the construction, increasing its overall dimensions and making operation of the clasp difficult.
It is for this reason that the invention seeks to define a solution for a clasp enabling an optimal compromise to be achieved between the wearing comfort and a satisfactory opening for the passage of a hand.
In addition, the invention seeks to define a clasp having small overall dimensions, user-friendly operation and/or an attractive appearance.
For this purpose, the invention is based on a clasp having deployant blades for a wristband, wherein the clasp comprises at least two blades, one movable blade being articulated on a second blade in the area of first extremities, the clasp being able to adopt a first closed configuration, in which:
The invention is defined precisely by the claims.
These aims, characterizing features and advantages of the present invention are explained in detail in the following description of individual embodiments that is made without limitation in relation to the accompanying figures, among which:
It has been established that, in a solution that is familiar from the prior art, such as that illustrated in
The invention notably makes an improvement to a suchlike clasp that is familiar from the prior art by making it possible for at least one movable blade to exhibit a second predefined form, which is conducive to the passage of a hand. A suchlike movable blade in its second predefined form defines a favorable overall form of the clasp its deployed configuration, but without necessarily increasing the length of the blades of the clasp. This length is advantageously between 20 and 60 mm. However, a suchlike solution is based on at least one movable blade of a clasp, which exhibits a first predefined form adapted to the closed configuration of the clasp, and which may exhibit a second, different predefined form in a deployed configuration of a clasp in order to be conducive to the passage of a hand. A suchlike solution thus makes it possible to maintain the optimal comfort of the clasp in its closed configuration, while optimizing the surface for the passage of a wrist in the deployed configuration.
Three individual embodiments of a suchlike clasp are now described in a detailed manner without limitation. For the sake of simplicity, the same references are used to designate identical or equivalent elements in the different embodiments.
In a first variant of the first embodiment, represented by
In fact, the movable blade 1 comprises two parts 11, 12 of substantially the same length that are interconnected in an articulated manner by an articulation A11. This articulation is angularly delimited by abutments 11a, 11b of the first part 11, cooperating with corresponding abutments 12a, 12b of the second part 12. These abutments define in an unambiguous manner first and second forms of the movable blade 1, in which the two parts 11, 12 occupy different respective positions.
The movable blade 1 may, in fact, adopt a first form C1 adapted to the closed configuration of the clasp. This first form thus approaches closely to the form of the second blade 2, on which the movable blade 1 rests in the closed configuration of the clasp, as illustrated in particular by
According to this embodiment, however, the movable blade 1 may exhibit a different predefined form C2, illustrated by
The amplitude of the respective rotation of the two parts 11, 12 of the movable blade, as well as their two extreme positions, are perfectly predefined by the abutments provided on the parts 11, 12. In the second form C2 of the movable blade, the second abutments 11b, 12b of the parts 11, 12 respectively bear against one another, as illustrated in
The operation of a suchlike clasp according to the embodiment described above takes place in a similar manner to that of the clasp that is familiar from the prior art illustrated by
Conversely, closing of the clasp includes the rotation of the movable blade 1 about the axis of articulation A1 as far as an intermediate configuration, of which an example is illustrated by
In this embodiment, the second blade 2 advantageously exhibits a hollow surface forming a housing 2a to accommodate the central articulation A11 of the movable blade 1, as can be seen in
In the major part of this operation of the clasp, in particular during rotation of the movable blade 1 relative to the axis of articulation A1, the two parts 11, 12 of the movable blade 1 continue to make contact via respective abutments, or have a reduced displacement, and the additional articulation A11 of the movable blade 1 compared to the prior art does not cause any obstruction in the operation.
It should be noted that the clasp according to the embodiment of the invention is equipped with a locking device, which makes it possible to keep the two blades 1, 2 secured to each other, in the closed configuration of the clasp, as depicted by
It should be noted that the two forms C1, C2 of the movable blade are predefined forms, in the sense that they are reached in a unique manner by a voluntary movement of the person wearing the watch until reaching an abutment. One or both of the predefined forms may or may not be stable forms. A stable form may be obtained, for example, by the combination of a certain resistance that is voluntarily imposed in the area of the articulation between the two parts 11, 12 about the axis of articulation A1 and the abutments.
The two parts 11, 12 of the movable blade have been selected to be of approximately the same length, their axis of articulation A11 being positioned substantially in the middle of the movable blade 1. As a variant, these parts could exhibit a different length.
Naturally, the embodiment is not limited to the example illustrated above. More particularly, the movable blade 1 may comprise more than two articulated parts. By way of example,
Thus, the movable blade 1 according to this variant of embodiment may also exhibit two predefined forms, depending on whether each articulation A11, A12, A13 is in a position defined by the first abutments or by second abutments.
This first form is convex, when viewed from the wrist, in the deployed configuration, similar to the form in
In a general manner, the absolute value of the radius of curvature of the movable blade 1 or of a portion of the movable blade 1 may vary, or may even vary significantly, when the movable blade 1 passes from its first form C1 to its second form C2. In the variant embodiment in
These couplings thus form necks, of which the behavior resembles that of an articulation A11, A12, A13 of the preceding embodiment. As a variant, other zones of reduced thickness could also form a coupling of the flexible pivot type. In this embodiment, the selected geometry is therefore based on two half circles having a radius r. This radius r of the half circles is preferably at least greater than four times the minimum thickness e of the movable blade 1. This condition allows the stresses to be distributed as effectively as possible and, in particular, allows any concentration of stresses in the middle of the neck to be avoided.
The movable blade 1 may be made advantageously from a super-elastic alloy, such as a nickel-titanium alloy like Nitinol, in order to maximize the thickness e and accordingly to optimize the resistance to traction and to torsion of the movable blade 1 for a given maximum angular displacement of the different blade portions.
Similarly to the first embodiment, a suchlike articulation is angularly delimited by abutments, so as to define the first and second predefined forms of the movable blade 1 in an unambiguous manner by the relative positioning of the different parts 11, 12, 13, 14 of the movable blade 1. These abutments are formed by lateral walls of each part of the blade in the area of each of the necks. In this particular construction, the necks advantageously do not cover the entirety of the transverse section of the movable blade 1, which retains lateral walls of unchanged thickness, although sectioned in order to permit pivoting and to form abutments. As a variant, the abutments could be eliminated, and the angular displacement could be limited by the actual rigidity of the necks. As a variant, the zones of reduced thickness could exhibit a different form, causing deformation of the blade enabling it to distance itself from a pure pivoting movement.
In this second embodiment, the movable blade 1 may accordingly exhibit a first predefined form C1 depicted in
In the embodiment in
Of course, it is possible to combine the preceding embodiments and variants. For example, it is possible to envisage a movable blade 1 comprising different types of articulations combining, for example, at least one articulation as proposed in the first embodiment, and at least one articulation as proposed in the second embodiment.
The movable blade 1 thus makes it possible to optimize the passage of a hand in the course of positioning the wristwatch on the wrist or in the course of removing the wristwatch from the wrist. In particular, the first part 11 of the movable blade 1 of substantially concave or rectilinear form thus offers an additional passage for the hand of the person wearing the watch compared to the solution that is familiar from the prior art depicted in
In the course of closing the clasp, the movable blade 1 pivots towards the second blade 2 about the axis of articulation A1, until the movable blade 1 comes into abutment with the blade 2 in the area of the respective abutment surfaces B1, B2. This intermediate configuration in abutment is illustrated by
The person wearing the watch then continues the closing movement of the clasp, which brings about the displacement of the movable blade 1 towards the second blade 2 and an elastic deformation of the movable blade 1. This elastic deformation of the movable blade 1 takes place primarily at the level of the part 11, for example, and can take place in particular at the level of the zone of inflection Z1. The movement continues until closure of the clasp, that is to say until the movable blade 1 has been secured to the second blade 2 of the clasp, for example, by an appropriate locking device 4, 5, 6. The movable blade 1 is thus deformed in such a way as to exhibit a first form C1, in which its curve is substantially constant and is intended to conform as closely as possible to the curve of the blade 2, as well as a wearer's wrist. The first form C1 of the movable blade is illustrated in
As a variant, this third embodiment could be obtained by any geometry of the movable blade 1 exhibiting at least one zone of inflection. It could, therefore, include a plurality of zones of inflection.
Advantageously, in this embodiment, the first part 11 exhibits a thickness e1 that is less than the thickness e2 of the second part 12, such that the first part 11 may be flexible, in particular in comparison with the second part, and may exhibit an optimized bending moment. On the other hand, the second part 12 is considered to be rigid and dimensionally stable in this embodiment, under the influence of the conventional operations of the person wearing the wristwatch.
Preferably, the two thicknesses e1, e2 of each part 11, 12 respectively verify:
e1<e2/2, or e1<e2/3;
e2˜e3, that is to say that the thicknesses e2 and e3 are substantially equal, where e3 is the constant thickness of the blade 2;
e1˜0.3 mm and e2˜1 mm.
The thickness e1 of the first part 11 may be constant for the entire length of the first part 11. Similarly, the thickness e2 of the second part 12 may be constant for the entire length of the second part 12. Alternatively, these thicknesses e1 and/or e2 may vary, in a continuous or discontinuous manner, in such a way as to propose a movable blade 1 that is deformable in flexion, while being sufficiently resistant to tension and resistant to torsion with respect to predefined criteria. The cross section of each of the parts may likewise vary in such a way as to meet these criteria.
According to a variant of the third embodiment, not depicted here, the movable blade 1 may simply exhibit a variable thickness over its length, without a zone of inflexion. This variable thickness forms a compromise which allows it to achieve sufficient flexibility for it to deform elastically between two different forms, while preserving sufficient mechanical rigidity for its operation.
Advantageously, the movable blade 1 may be made from a super-elastic alloy, for example a nickel-titanium alloy such as Nitinol.
Preferably, the elastic potential energy accumulated by the elastic deformation of the movable blade 1 in its first form, in the closed configuration of the clasp, may be utilized in order to contribute to the locking and/or unlocking function of the movable blade 1, in cooperation with a locking device 4, 5, 6 of the two blades 1, 2 of the clasp. In particular, the elastic potential energy accumulated by the elastic deformation of the movable blade 1 in its first form may be utilized in order to facilitate the opening of the clasp, namely to permit the distancing of the movable blade 1 relative to the second blade 2, by its pivoting about the axis A1 of articulation, without a significant contribution by the person wearing the wristwatch.
The invention is illustrated in the context of a clasp having deployant blades comprising two blades 1, 2. As a variant, the clasp could exhibit any architecture other than that depicted in the figures. It could comprise a greater number of deployant blades. For example, it could comprise three blades, of which two blades are movable blades arranged respectively at the two extremities of a third central blade and are locked in the central part of this third blade in the closed configuration of the clasp. In this case, one movable blade or the two movable blades could comprise a plurality of parts that are movable in relation to one another in order to obtain two predefined forms.
The movable blade is illustrated as being folded back onto another blade in the closed configuration, its closed position being fixed by a locking device. As a variant, a simple retaining device, for example by a simple snap-fit, and/or any other locking device may be provided for the temporary and releasable attachment of the movable blade to the clasp in the closed configuration of the clasp. As a variant, this movable blade could occupy a different position in the closed configuration of the clasp, for example totally interlocked or partially interlocked in another blade. More generally, the movable blade thus extends in a continuous manner on its entire length substantially along the surface of a second blade in the closed configuration of the clasp.
According to the architecture of the clasp, the movable blade may adopt a plurality of geometries. A movable blade of a clasp is defined in the sense of the invention as a blade comprising an articulation in the area of a first extremity, about which it pivots in relation to another blade of the clasp for the passage from a closed configuration to a deployed configuration of the clasp, or vice versa, and which extends continuously from its first extremity towards a second extremity in the closed configuration of the clasp.
This movable blade comprises two predefined forms, that is to say that these forms may be obtained in a repeated and reliable manner, in an automatic manner or under the effect of a given actuation by a person wearing the clasp. These forms may be predefined in different ways, by the geometrical and/or mechanical properties of the movable blade. In addition, a predefined form may or may not be stable: a form is stable when it is maintained automatically once it has been reached, in the absence of any stress exerted by a wearer.
The invention is illustrated on the basis of a clasp intended for a bracelet, said bracelet being intended for a wristwatch. The invention thus also relates to a bracelet and to a wristwatch as such, comprising a suchlike clasp. As a variant, the clap may be associated with any other bracelet, for any object other than a watch to be secured on a wrist or any other part. This object may be a “Smart” watch, an underwater diving accessory such as a depth gauge or an underwater diving computer, for example, or even a jewelry component.
| Number | Date | Country | Kind |
|---|---|---|---|
| 17177805.3 | Jun 2017 | EP | regional |
