HK1189135B - Fermoir a boucle deployante - Google Patents

Description

Hasp with unfolding type buckle

Technical Field

The present invention relates to a buckle with an unfolding buckle, and more particularly to a locking device for such a buckle.

Background

Wristwatches are generally distinguished by so-called "open" watchbands, which means that the two strips of the watchband can be separated from each other, and by so-called "closed" watchbands, which means that the two strips of the watchband are joined by a clasp with an unfolding buckle, which comprises a plurality of blades that can be crossed by the watchband in the unfolded position and are sufficient to be applied against the wrist in the closed position. The open band generally comprises two strips made of leather, a first strip having a buckle and a pin at its end, and a second strip comprising a series of through holes, one of which can be crossed by the pin according to the desired length of the band. Closed watchbands with unfolding buckles, which are usually made of steel, typically comprise a push button that can be actuated by a reverse movement against a rod spring, perpendicular and perpendicular to the blade. In this case, the length adjustment is made by removing a series of chain links.

In order to overcome the drawback of the closed watchband that it is not possible to finely adjust its length, and in order to overcome the drawbacks of the open watchband in terms of convenience of use and service life, there are hybrid solutions in the prior art for flexible watchbands having blades that constitute an unfolded buckle, with a projection being provided on the buckle, said projection being designed to pass through a through hole in one of the straps. Such a system allows fine adjustment of the length of the wristband when needed, for example when the size of the seasonal change clasp pin may vary due to temperature, and at the same time has the advantage of being able to be opened and closed conveniently and quickly every day with the clasp of the unfolding type buckle system.

For this type of snap, the fastening system between the blades usually employs notches projecting on said blades, said notches being adapted to receive a bar, or a bolt provided on one blade and passing through a through hole provided on the other blade. A disadvantage of this type of locking element is that on the one hand it breaks relatively quickly and on the other hand it runs the risk of being relatively fragile, since their construction makes it less stable.

There is thus a need for a buckle with an unfolding buckle that overcomes the deficiencies of the prior art.

Disclosure of Invention

The object of the present invention is to provide an alternative to the known buckles with unfolding buckles, which are structurally simple and whose locking is more secure.

These objects are achieved, inter alia, by a clasp (buckle, clasp) with an unfolding buckle, comprising a first blade (leaf) and a second blade hinged around a hinge, the first blade being attached to a first strip (band segment) of a watchband, the second blade being attached to a second strip of a watchband, the clasp further comprising locking means for securing the first blade to the second blade when the blades are folded (folded over, closed, rabattre) on each other in a closed position (locking position) of the clasp, the locking means comprising a first locking element of a male type and a second locking element of a female type, the first and second locking elements engaging each other when the clasp is in the closed position, characterized in that the first blade or the second blade exerts a locking force between the first locking element and the second locking element, to maintain the mutual engagement between the locking elements when the buckle is in the closed position.

One advantage of the proposed solution is that wear of the locking elements is reduced, since the locking elements do not have to be plastically deformed in order to fix the blades to each other.

Another advantage of the proposed solution is that it ensures that the hasp permanently achieves a good safety locking, in particular with a good resistance against impacts (shocks), since in the closed position of the hasp a locking force is applied that presses the leaves against each other and the locking elements remain engaged in a stable and durable manner.

Drawings

A preferred embodiment of the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is an exploded view of the various component parts of a clasp for a flexible wristband according to a preferred embodiment of the invention;

FIG. 2 is a top view of the buckle according to the preferred embodiment shown in FIG. 1, in an assembled position and closed;

FIG. 3 is a perspective view of the clasp according to the preferred embodiment of FIG. 1, with the blade in the deployed position and a strap of a watchband attached to the end of the blade;

FIG. 4A is a perspective view of the buckle according to the preferred embodiment shown in FIGS. 1-3, with the buckle in a locked position;

FIG. 4B is an enlarged view of FIG. 4A, showing more particularly the insertion of the male type locking element of the buckle into the female type locking element in accordance with a preferred embodiment of the present invention.

Detailed Description

In the following, a preferred embodiment of the invention will be described in detail, suitable for a flexible bracelet, but it will be understood that the blade locking system proposed by the invention can be used for other types of bracelet, for example made of metal.

Fig. 1 is an exploded view of the component parts of a buckle 100 according to a preferred embodiment of the invention, comprising a first central leaf 1 which is flattened (like a stretcher) between first and second legs 21, 22 in the closed position of the buckle 100 to minimize the height of the assembly. The first and second blades 1, 2 are hinged at one of their ends by a hinge 3, the hinge 3 being constituted for example by a tube 31 whose end is closed by a plug 32, the first central blade 1 comprising at its end a head 14 for fixing, which is connected to a tie (attachment) 6 of a first strap 101 of the bracelet, as shown in figure 3, so that the stretcher component is connected at its other end to a first fixing bar 4 of a buckle 5, the upper bridge 51 of the buckle 5 comprising a nose 54, here constituted by a tapped tube (threaded tube) 541 and a head screw 542, which is designed for insertion in a hole (through hole, eyelet) 10 of the end of a second strap 102 of the bracelet, as shown in figure 3 and as will be explained below. The tie fastener 6 comprises a central claw 61 to centre the first strip 101.

The central blade 1 comprises a first transverse hole 12 for the passage of a pin constituting a first locking element 7 of the male type, the end of which protrudes from both sides of the central blade 1, and a second hole 13 for the passage of a nose 54, thus allowing the buckle 5 to be completely folded over said blade when the latter is in the closed position. At the upper surface 15 of the central blade 1 there is a first recess (hollowed-out portion) 11, preferably cylindrical, for the first fixed bar 4 to pass through, and there are second and third recesses, see recess 211 in the first leg 21 and recess 221 in the second leg 22 of the stretcher, respectively. The second recess 211 and the third recess 221 constitute an accommodating portion for accommodating the protruding end portion of the pin. These two recesses 211 and 221 are provided at the lower surface 24 of the stretcher part-visible in fig. 4A and 4B-and constitute the female-type second locking element 8 of the clasp. This arrangement of the male and female type locking elements 7, 8 not only reduces the height dimension of the buckle in the closed position, but also partially conceals the locking elements so that they are not visible from the upper part of the buckle 100.

In order to increase the width of the buckle 5, which must be able to pass a strap of a watchband and which therefore must be greater than the width between the lateral surfaces 20 of the stretcher part, a widening tube 9 can be provided at the end of the first securing bar 4 of the buckle 5. It is noted that, in fact, the space between the first branch 52 and the second branch 53 of the buckle 5 is greater than the space between the lateral surfaces 20 of the stretcher.

At the second and third recesses 211 and 221, bosses are also provided to enhance retention of the pin in the closed position of the buckle, and the inclined contact surfaces reduce deformation of the central leaf when the first and second legs 21, 22 of the stretcher member are pivotally overlapped. The first boss provided on the first leg 21 of the stretcher member is referenced 212 and the second boss provided on the second leg 22 of the stretcher member is referenced 222. Similarly, the first support surface provided on the first leg 21 of the stretcher member is designated 213 and the second support surface provided on the second leg 22 of the stretcher member is designated 223. A detailed view of the boss and the inclined face is shown in fig. 4B and will be described in detail later.

Fig. 2 is a top view of buckle 100 with all of the components of fig. 1 assembled. The clasp is shown in the figure in the locked Position (PV) in which the first central blade 1 is between the first and second legs 21 and 22 of the stretcher member to which the buckle 5 is attached by means of the first fixing bar 4 and the widening tube 9, the buckle being superposed on the first central blade 1 and the nose 54 being intended to engage in the second hole 13. It should be pointed out that the arm of the pin constituting the first locking element 7 of the male type of the locking device according to the invention extends parallel to the axis of the hinge 3, which hinge 3 is constituted by a tube 31 and a plug 32 and is adjacent to the fixed bar 4, so that the tie fastener 6 is coupled to the fixed head 14 of the first central blade 1.

In figure 1 and more mainly in figure 4A described below, according to a preferred embodiment of the invention, in the closed position the radius of curvature of the first blade 1 is the same as that of the second blade 2; however, in fig. 3, the first radius of curvature C1 of the first central leaf 1 is greater than the second radius of curvature C2 of the second leaf 2, that is to say, in the rest position, the curvature of the first leaf 1 is less than that of the second central leaf 2, as shown in the unlocked position (D) of the clasp 100 in fig. 3, in which the male locking element 7 is visible, the first and second straps 101 and 102 respectively carry respective fixing elements for fixing them to said leaves, i.e. the first strap carries the tie 6 and the second strap carries the buckle 5, while the nose (not visible in the figures) is located on the lower face of the bridge 51 and penetrates into an aperture 10 of the second strap 102 to adjust the length of the strap. On the tie-down 6, a central claw 61 is visible, which can be inserted into the slot at the end of the first strip 101 and ensures that it is centred around the fixing bar (not visible in the figures).

The locking element 7 of the male type may be not only pin-shaped as described above, but may also consist of an arm integral with the first central blade 1. According to a variant, it is also possible to provide on one of the blades a portion of the male locking element 7 and a portion of the female locking element 8, while on the other blade another portion of the first and second locking elements 7, 8 is provided. The preferred solution is a pin which preferably fits tightly in the first hole 12 of the first central blade 1, because the material of the pin can be chosen to be harder than the blade, which has to be sufficiently deformable to allow the user to fix the blade without great force. It is also possible to choose a harder material for the blade 2 than for the blade 1, in which blade 2 the locking element 8 of the female type (second and third recesses 211 and 221) is made, and it is further preferable to choose a harder material than for the pin, so that the pin is used as a wear part, i.e. a part to be replaced after a certain time, since replacing it is much cheaper than completely replacing the bracelet. According to a variant, the pin can be welded after insertion in the first hole 12 of the first central blade 1, in order to increase the retention and to permanently prevent it from moving laterally along the axis of the hole.

Whatever the material chosen for the first and second locking elements 7, 8, the locking device proposed according to the invention has a better durability than the usual snap-action, which uses locking elements fixed with respect to the blade and a snap-action with the male part inserted into the female part, since this fixing method requires plastic deformation of the locking elements each time the snap-action is opened and closed. Furthermore, the plastic deformation needs to be large in order to ensure the safety of the locking in the closed position, which on the one hand results in inconvenience of use in view of the force that has to be applied to engage and disengage the locking elements from each other and on the other hand results in rapid wear of the parts used in the locking.

In contrast, according to the present invention, there is no need to plastically deform the locking elements, because only one blade needs to be deformed to engage and disengage the locking elements from each other. In addition to the advantage of facilitating assembly, the method proposed by the invention does not require the use of additional elastic members to exert a return force, the conventional transverse push bar remaining protruding from the cover of the clasp to allow the metal bracelet to be removed.

Fig. 4A shows the buckle 100 of the preferred embodiment of the present invention shown in the previous figures in a top view, with the buckle in the locked Position (PV). On the left side of fig. 4A, the tie buckle 6 and the buckle 5 can be seen, as well as a locking element 7 of the male type, and also a widening tube 9 on an extension along the axis of the first bar 4 (not visible in the figure). The lower surface of the blade, in particular the lower surface 24 of the second blade, is visible in the figures, where the locking element 8 of the female type, i.e. the recess for receiving the locking element 7 of the male type, is provided, and the second hole 13 of the central blade is also visible. On the right side of the figure, the hinge for fixing and hinging the first leaf 1 to the second leaf, here the central leaf and the stretcher member, can be seen.

Fig. 4B is an enlarged view of the locking element of fig. 4A. Here can be seen the locking force F exerted by the central blade, the coupling of the locking element 7 of the male type to the second element 8 of the female type of the bottom, the second part 8 of the female type, i.e. the second and third recesses 211 and 221. In this figure, it is to be explained that the fitting takes place only between one arm of the pin and the second recess 211 on the first leg 21 of the stretcher member, which second recess 211 is the only female-type second member 8 visible in this figure. The locking force F is exerted in a direction corresponding to the direction towards the central blade which, in the closed position of the clasp, is restrained so as to have the same radius of curvature as the stretcher member and can return so as to resume its rest position with a significantly smaller radius of curvature. This locking force F corresponds according to this embodiment to a restoring force returning the first blade 1 to the rest position, which locking force extends to the left in a direction at 45 ° with respect to the vertical direction, i.e. to the left bottom of the second recess 211, so that in the locked position both blades can be held pressed against each other in a stable manner.

In order to enhance the retention of the fixation, the second locking element 8 of the female type preferably defines a housing having a depth greater than or equal to the size of the first locking element 7 of the male type, here the diameter of the projecting arm of the pin, the first and second legs 21 and 22 of the stretcher member comprising respectively the first and second bosses 212, 222. Although only the first boss 212 is visible in fig. 4B, it should be understood that the second boss 222 may preferably be identical to the first boss, obviously only one boss is sufficient to achieve the function of retaining the pin by one of the arms. The first boss 212 is located in a lower portion of the first recess 211 to constitute a convex boundary of the receiving portion in which the arm of the pin is inserted to perform a snap-lock. The lower portion of the boss is formed by an inclined first support surface 213 (note: preferably a second support surface 223 is similarly formed on the second leg 22 of the stretcher member, but not shown in the figures). Locking and unlocking of the catch can be made easier by sliding the pin more easily up to the boss, i.e. with less deformation of the central vane. The inclination of the bearing surface may preferably be about 45 degrees in order to not deform the central blade too much when the pin slides on the surface, but it is also possible to configure an intermediate deformation threshold on the boss before the pin engages in the respective housing. The vertical arm, i.e. the left part of the housing, is obviously also within the scope of protection of the present invention, but it has the drawback of causing a large initial force threshold for the mutual engagement between the locking elements; furthermore, the absence of a projection is disadvantageous in terms of locking security, since the central blade is moved downward with force, for example in the event of a crash, as a result of which the pin is relatively easily removed from the receptacle. The support surface preferably extends upwards, or at most 1 to 2 mm, and preferably a distance which is at most equal to the radius of the pin.

In fig. 4B it is noted that the arm of the pin extends as far as the outer side wall 20 of the first leg 21 of the stretcher part, which enables the user to easily see whether the clasp is in an effective closed position by looking across the clasp in a lateral direction, i.e. parallel to the axis of the hinge 3, and the locking means is not visible from above, since it is hidden by the buckle 5 according to the preferred embodiment. Furthermore, the extension of the arm corresponding to the pin to be flush with the outer side wall enhances retention of the fixation. The length of the arm of the pin is preferably such that no part of the arm protrudes beyond the side wall, in order to avoid hooking or scratching external elements (such as the skin or the supporting shell of a watch strap).

Also visible in fig. 4B is a first fixed end 210 of the first leg 21 of the stretcher member, which first fixed end 210 defines the axis of the first fixed bar 4 of the buckle 5 and of a second fixed end 220 of said second leg 22 of the stretcher member, which is not visible in this figure, with the axis of the pin in their vicinity. The first and second fixed ends 210, 220 are located at the ends of the first and second legs 21, 22 of the stretcher member, preferably at most 5 mm from the pins. In order to maximize the moment and leverage effect exerted by the locking force F in the closed position of the buckle, a spacing of at most 2-3 mm may be chosen between the axis of the pin and the axis of the bar, as described according to the preferred embodiment shown.

The provision of said first and second recesses on the lower surface 24 of the stretcher member and the cylindrical recess 11 on the upper surface 15 of the central blade not only allows to cover the locking system, but also facilitates unlocking the system by exerting a pressure on the tie-down 6, which causes the central blade to bend downwards and generate an unlocking force opposite to the locking force F. Conversely, it should be pointed out that the bridge 51 of the buckle 5 constitutes a dedicated support surface to perform the locking of the buckle when the blade is in contact with the user's wrist. The lever effect facilitates the locking of the buckle, which on the one hand enhances the movement of the bridge 51 relative to the axis of the fixed bar 4 and on the other hand increases the size of the fixed end 14 of the tie 6, which further creates a support point further away from the axis of the fixed bar, thus increasing the moment of the force applied at the support point.

According to the above embodiment, the pin and more generally the first locking element 7 of the male type are configured to extend in a direction perpendicular to the locking force F, so as to maximize the total contact area with the element of the female type. Furthermore, the provision of the pins makes it possible to avoid machining elements of the male type extending along the curvature of the blade to be fixed.

According to a variant, it is possible to choose the blades to have the same radius of curvature at rest, and to have a small change in their respective radii of curvature when the male element is engaged in the female element, the first radius of curvature of the first blade increasing and the second radius of curvature of the second blade slightly increasing.

The clasp 100 described within the scope of the invention is particularly suitable for a watch bracelet, but it will be understood that it can also be applied to various types of wristbands, with or without a buckle for removable attachment to one of the straps.

Claims (12)

1. Clasp (100) with unfolding buckle, comprising a first blade (1) and a second blade (2) hinged around a hinge (3), said first blade (1) being attached to a first strip (101) of a watchband and said second blade (2) being attached to a second strip (102) of a watchband, said clasp further comprising locking means for fixing said first blade (1) to said second blade (2) when these blades are folded onto each other in the closed position of the clasp, said locking means comprising a first locking element (7) of the male type and a second locking element (8) of the female type, said first and second locking elements engaging each other in the closed position of the clasp, characterized in that: one of said first blade (1) and said second blade (2) exerts a locking force (F) between said first locking element (7) and said second locking element (8) so as to maintain the mutual engagement between these locking elements in the closed position of the clasp, wherein said first locking element (7) is a pin inserted in a first transverse hole (12) of said first blade (1), said pin extending parallel to the axis of said hinge (3) to both sides of said first blade (1), wherein said first blade (1) is a central blade, said second blade (2) is a stretcher comprising a first leg (21) and a second leg (22), the first and second legs (21, 22) of said stretcher comprising a first and a second inclined contact surface (213, 223), respectively.

2. The buckle (100) with the expansion buckle according to claim 1, characterized in that: the first locking element (7) of the male type is fixed with respect to the first blade (1) or the second blade (2).

3. The buckle (100) with the expansion buckle according to claim 1 or 2, characterized in that: the first locking element (7) of the male type extends in a direction perpendicular to the locking force (F).

4. The buckle (100) with the expansion buckle according to claim 1, characterized in that: the second locking element (8) is formed by a first recess (211) provided in the first leg (21) of the stretcher part and a second recess (221) provided in the second leg (22) of the stretcher part.

5. The buckle (100) with the expansion buckle according to claim 4, characterized in that: the first and second legs (21, 22) of the stretcher are coupled to a first fixing bar (4) of a buckle (5) provided with a nose (54) for fixing the second strap (102), the central first blade (1) comprising a cylindrical recess (11) for the passage of the fixing bar (4) and a second hole (13) for the passage of the nose (54).

6. The buckle (100) with the expansion buckle according to claim 5, characterized in that: the first and second recesses (211, 221) are arranged on the lower surface (24) of the stretcher member and the cylindrical recess (11) is arranged on the upper surface (15) of the central blade.

7. The buckle (100) with the expansion buckle according to claim 6, characterized in that: the first fixed bar (4) is fixed to a first end (210) of a first leg (21) of the stretcher member and to a second fixed end (220) of a second leg (22) of the stretcher member, and the axis of the first fixed bar (4) is spaced from the axis of the pin by a maximum of 5 mm.

8. The buckle (100) with the expansion buckle according to claim 1, characterized in that: the second locking element (8) of the female type defines a housing having a depth greater than or equal to the size of the first locking element (7) of the male type, the first and second legs (21, 22) of the stretcher member comprising a first and a second boss (212, 222), respectively.

9. The buckle (100) with the expansion buckle according to claim 1, characterized in that: the pin extends to an outer side wall (20) of the first and second legs.

10. The buckle (100) with the expansion buckle according to claim 1 or 2, characterized in that: the first blade (1) comprises a fixing end (14) of a fastener (6) provided with a central claw (61) for fixing the first strap (101).

11. The buckle (100) with the expansion buckle according to claim 1 or 2, characterized in that: in the unlocked position (D) of the clasp, the first blade (1) and the second blade (2) in the rest state have different radii of curvature (C1; C2).

12. The buckle (100) with the expansion buckle according to claim 1 or 2, characterized in that: the first locking element (7) of the male type is made of a material that is harder than the material of which the second locking element (8) of the female type is made.