HK1188303A - Device for attaching an interchangeable bracelet for a timepiece - Google Patents

Description

Strap-fastening device for a timepiece with interchangeable bands

Technical Field

The object of the present invention is a quick fastening device for an interchangeable bracelet of a wristwatch, comprising a body which acts as a push-button and is housed slidably in a watchcase, the body carrying a retaining bar arranged parallel to the plane of the watchcase and in the sliding direction of the body, so that the body can move parallel to the longitudinal axis of the retaining bar.

Background

Such devices are known in principle. For many years there have been a number of devices that allow the watchband to be removably fixed to a watch. However, most of these devices are too complex in design, require tools to perform the replacement of the bracelet, run the risk of accidental detachment of the bracelet, cannot be easily integrated in the existing watch case on an industrial scale, or have other drawbacks such as simply a less aesthetic appearance, which is of considerable importance in this field.

For example, patent document US5,914,913 discloses an interchangeable watchband system that uses a pair of pivots housed in two hinges, positioned laterally on the case, and able to be pulled by respective push-buttons to enable the pivots to be removed from respective housings arranged on connecting elements at the ends of the watchband, intended to be interposed between said hinges. This system is very difficult to integrate in most watchcases present on the market, since it requires two buttons that should be pulled outwards and is, for the same reason, complicated to use, while being less aesthetically pleasing.

A similar evaluation is also applicable to the device proposed in european patent application EP 1400875. In a way, this device implements a system that operates in contrast to the device from patent document US5,914,913, which has a pair of pivots housed in a single hinge positioned laterally on the case, these pivots being disengageable from the interchangeable bracelet around this hinge and receiving them in respective housings by pushing a push button, which acts on the pivots inside the hinge, allowing the disengagement of the bracelet. Although perhaps more suitable for use than the device from patent document US5,914,913, this system does not overcome the other drawbacks mentioned above and moreover has the risk of accidental actuation by the user of the watch, since the push-button is operated by pressing, rather than pulling.

Swiss patent application CH664663 relates to a bracelet clasp having two buttons arranged on either side of the clasp and each extended by a shaft of variable diameter, the two buttons being able to cooperate with two lugs fixed on the case and provided with a slit allowing the shaft to slide in the lugs when the button is pushed and to lock in the lugs when the button is released. As with the device from patent document EP1400875, this system is based on the principle of two external buttons actuated by pressing and thus has the same significant drawback of a high risk of loss of the wristband due to accidental actuation of the buttons. At the same time, the system does not overcome the other drawbacks mentioned above, in particular, it does not improve the aesthetics, since additional components of significant dimensions are added in the form of snap fasteners.

Patent document CH179155 discloses two embodiments of a fixing device for interchangeable watchbands. The first embodiment uses a push-button mounted perpendicularly with respect to the plane of the watch case and allowing the locking or unlocking of the corresponding interchangeable watch strap, this end being in the form of a large tongue of a particular shape. A second embodiment uses a locking shaft which is rotatably mounted in the watch case and cooperates with a tongue of the same particular shape, arranged on the end of the bracelet. If the two proposed devices therefore require a particular bracelet, in particular with a tongue of said particular shape, which does not allow the use of most of the bracelets on the market, the second proposed device also requires the use of a tool, such as a screwdriver, to perform a 90 ° rotation of the locking shaft to allow the re-pulling or fixing of the bracelet on the watch, which makes the use of this type of interchangeable bracelet rather unsuitable.

Other such devices are also disclosed in the patent documents JP2006/296544, US5,416,953, GB2264628, JPH0174813 and CH73121, however the proposed system does not overcome all the drawbacks mentioned above as well. The known prior art solutions are therefore not considered satisfactory in all respects as cited above.

There is therefore always a need for: a quick-action fastening device with an interchangeable bracelet of the type described above, which is relatively uncomplicated to construct, operates reliably, is not awkward or even requires the use of tools, and can be used with a large number of watchcases and bracelets existing on the market. Furthermore, it is desirable and important to achieve these objects while guaranteeing a moderate production cost and providing an attractive appearance to the watch in which the device is integrated.

The object of the present invention is therefore to overcome the drawbacks of the known devices and to achieve the aforementioned advantages, and in particular to allow the implementation of a quick fastening device for interchangeable watchbands, which is simple to design and use, reliable to operate, small, sturdy and aesthetically pleasing, while reducing the production costs of the device and improving the compatibility of the device with existing watchcases and watchbands.

Disclosure of Invention

To this end, the invention proposes a quick-fastening device for an interchangeable strap of a watch of the aforementioned type, comprising a body which acts as a push-button and is housed slidably in a watch case, said body carrying a retaining bar arranged parallel to the plane of said watch case and in the sliding direction of said body, so that said body can move parallel to the longitudinal axis of said retaining bar, and a corresponding watch and interchangeable strap comprising such a device. In particular, in the device according to the invention, the body cooperates with a spring arranged substantially parallel to the retaining rod and exerting a prestress which restores the body acting as a push-button to the rest position, the retaining rod having a particular shape with a reduced thickness in at least one predetermined position along its longitudinal axis with respect to a reference thickness possessed by the rest of the retaining rod; and said quick fastening means comprise at least one fastening element able to be mounted on an end of said interchangeable watch strap and comprising a slot of complementary shape to that of the retaining bar able to cooperate with the fastening element or elements, depending on its position along said longitudinal axis, to allow said interchangeable watch strap to be fastened to or removed from the watch case.

In a preferred embodiment of the device according to the invention, the retaining rod comprises guide flanks in at least one predetermined position, preferably in two predetermined positions, such that the guide flanks are aligned with the slots of the fastening element when the body serving as the push button is actuated, and are at least partially offset with respect to these slots when the body serving as the push button is in the rest position.

By these measures, a device is obtained which is simple to use, since only a single button is used, and which is also particularly simple in design. The small size of the device allows integration in a large number of existing watchcases by machining provided with corresponding housings. Likewise, the presence of the fastening elements allows the device to be combined with a number of pre-stored watchbands without requiring major modifications to these watchbands.

Said body acting as a push-button is preferably arranged so as to have, in the rest position, an outer surface which is aligned and coincident with respect to the outer surface of the watch case for the integrated body, which makes the operation of such a device particularly safe and reliable, since accidental actuations can be almost excluded. At the same time, this arrangement makes the aesthetic appearance of the bracelet incorporating such a device particularly advantageous, the buttons being practically invisible on the watch case.

The invention also relates to a watch case and a corresponding interchangeable watch strap.

Drawings

Further features and corresponding advantages will appear from the independent claims and from the description which follows, which presents the invention in more detail.

The figures show an embodiment of the invention schematically and by way of example.

FIG. 1a is a schematic perspective view of an interchangeable watch strap mounted on a watch case by means of a quick fastening device according to the invention; FIG. 1b is a perspective view similar to FIG. 1a, with an interchangeable watch band removed from the watch case; FIG. 1c is an exploded perspective view of the quick fastening device according to the invention and the corresponding watch case and interchangeable watch strap; FIG. 1d is a side view of the interchangeable watch strap of FIG. 1a, the watch strap being fastened to the watch by means of a device according to the invention; figure 1e is a cross-section through the quick-fastening device according to the invention, respectively the corresponding watch case and interchangeable bracelet, along the line I-I indicated in figure 1d, the device being in the rest position.

FIG. 2a is a perspective view of one embodiment of a body used as a push button and a retaining bar of the quick hitch apparatus according to the present invention; FIG. 2b is an exploded perspective view of the body and the retaining rod prior to assembly; FIG. 2c is an enlarged view of area A indicated in FIG. 2a, with certain portions shown in transparency for better understanding; fig. 2d is a longitudinal cross-sectional view through a fastening element of the rapid fastening device according to the present invention, particularly illustrating the particular shape of the slit of the fastening element.

Figure 3a shows schematically, in a side view, a quick fastening device according to the invention, respectively a corresponding watch case and an interchangeable watch strap, in an assembled state when the quick fastening device is in a rest position, some parts being shown in transparency for a better understanding; FIG. 3b is a longitudinal cross-sectional view through the quick fastening device according to the present invention along the line II-II indicated in FIG. 3 a; FIG. 3c shows, by a side view similar to FIG. 3a, when the quick fastening device is in the actuated position, the quick fastening device according to the invention, respectively a watch case and an interchangeable watch strap, with parts shown in transparency for better understanding; fig. 3d shows a longitudinal section through the quick fastening device along the line III-III indicated in fig. 3 c.

Detailed Description

The invention will now be described in more detail with reference to the accompanying drawings, which show by way of example an embodiment of the invention.

The rapid fastening device 1 of the interchangeable bracelet 3 according to the invention is intended to be integrated in a watch piece, in particular a wristwatch 2. As this is illustrated schematically and by way of example in fig. 1a and 1b, which show a perspective view of an interchangeable bracelet 3 mounted on a watch case 2 by means of a quick-fastening device 1 according to the invention, respectively the same bracelet in a disassembled state detached from the case, this quick-fastening device 1 allows to fasten and detach the bracelet 3 to and from the watch case 2, the user hardly notices the difference between the interchangeable bracelet 3 and the usual bracelet in terms of the appearance of the watch fitted with this device.

Fig. 1c, which is an exploded perspective view of a quick-fastening device 1 of the type according to the invention, and of a corresponding watch case 2 and interchangeable watch strap 3, makes the main components of the device clearly visible. The watch itself is not essential to the invention and may be any type of watch, mechanical or electronic in motion and analog or digital in display, shown only by the case 2 on the drawings. The tie-down device 1 comprises a body 1.1, which acts as a push-button and is housed slidably in the case 2 of the corresponding watch, the movement being applied along an axis parallel to the spring catch lever, which is usually located on a conventional watch case. This body 1.1 carries a holding rod 1.2, which is arranged parallel to the plane of the watch case 2 and in the sliding direction of said body 1.1 in the assembled state assembled with the watch case 2. The body 1.1 and the retaining rod 1.2 can thus be moved parallel to the longitudinal axis of said retaining rod in a manner replacing the usual spring catch.

Furthermore, the body 1.1 cooperates with a spring 1.3, which is arranged substantially parallel to the retaining rod 1.2 and exerts a prestress which returns the body 1.1 serving as a push button to the rest position. This is particularly well visible on fig. 1e, which shows a cross-sectional view through the tie down device 1 along the line I-I indicated in fig. 1 d. Fig. 1e also shows that the spring 1.3 can be fastened, for example, to the free end of a pin 1.1.1 which is mounted on the body 1.1 serving as a push button and is arranged parallel to the retaining rod 1.2. Preferably, the spring 1.3 is a helical spring. Generally, the spring 1.3 is chosen such that its prestress allows avoiding accidental actions of the body 1.1 acting as a push button. Fig. 1a and in particular fig. 1e simultaneously show that the body 1.1 serving as a push button is arranged so as to have, in its rest position, an outer surface 1.1.2 aligned and coincident with the outer surface 2.1.1 of the casing 2.1 of the watch case 2, said body being intended to be integrated in the watch case. The risk of accidental action of the body 1.1 can thus be further reduced and since the push-button is integrated in a completely unobtrusive manner, this at the same time provides a particularly advantageous appearance to the corresponding watch.

The retaining bar 1.2 mounted on the body 1.1 has a particular shape and, in at least one predetermined position along its longitudinal axis, a reduced thickness 1.2.1 relative to a reference thickness 1.2.2 of the rest of the retaining bar 1.2. According to a preferred embodiment shown on the drawings, and as can be seen in particular on fig. 2a and 2c, the retaining bar 1.2 is made of a bar body of constant diameter and comprises a guide land 1.2.1.1, the length of which represents: a part of the length of the retaining bar 1.2 is at least one predetermined position, preferably at two predetermined positions, along its longitudinal axis. It is particularly preferred to arrange two guide lands 1.2.1.1 on opposite sides and parallel to each other in each of said predetermined positions, as is also illustrated from fig. 2c, which is an enlarged view of the area a indicated in fig. 2a, some parts being shown in transparency for a better understanding of the component structure. The retaining bar 1.2 thus has a reduced thickness 1.2.1 over the entire length of the predetermined position and viewed from a particular orientation, i.e. a direction perpendicular to the plane of the guide land 1.2.1.1, while over the remaining length thereof the retaining bar has a reference thickness 1.2.2 or a thickness between these two extremes in length of the predetermined position, although the thickness between these two extremes is measured in a direction outside the direction perpendicular to the plane of the land 1.2.1.1.

Fig. 2b shows schematically an exploded perspective view of the body 1.1 and the retaining rod 1.2 before their assembly, the body 1.1 having a blind hole able to receive an end of the retaining rod 1.2, the blind hole having a first indexing land 1.1.3 able to cooperate with a second indexing land 1.2.1.2 located on said end of the retaining rod 1.2, so as to allow, once the two components are assembled, the precise orientation of the guiding land 1.2.1.1 with respect to the body 1.1 to be guaranteed, or, once the body is inserted in the case 2, for example with reference to the upper face of the case 2 on the housing portion of the body 1.1, the precise orientation of the guiding land 1.2.1.1 with respect to the case 2. Furthermore, such assembly may be performed by a variety of methods, such as by welding, by brazing, by gluing, or any other suitable method. It is also possible to manufacture the body 1.1 and the retaining rod 1.2 as one piece.

The retaining bar 1.2 also comprises an end element 1.2.3, which is visible, for example, on fig. 1c and on the sectional view of fig. 1 e. This end element 1.2.3 is mounted on the free end of the retaining rod 1.2, opposite to its end fixed to the body 1.1, which acts as a push-button, and allows to protect this body 1.1 from any fall-off from the watch case 2. In fact, as can be seen in particular in fig. 1c, the body 2.1 of the respective watch case 2 comprises, on each of the opposite lateral edges, a housing 2.1.2 able to receive the body 1.1, the retaining bar 1.2 and the spring 1.3 of the tie-down device 1. When the quick fastening device 1 and the corresponding watch case 2 are assembled, the body 1.1, the retaining rod 1.2 and the spring 1.3 are inserted into the housing 2.1.2 from the side for receiving the body 1.1. The end element 1.2.3 is then inserted into the housing 2.1.2 from the opposite side and fixed on the free end of the retaining rod 1.2, for example by screwing or any other suitable method, to lock the body 1.1 in the housing 2.1 in the housing 2.1, while allowing a translational movement of the body 1.1 following the action of the user. This configuration is clearly visible in fig. 1 e.

The exploded perspective view of fig. 1c and the sectional view of fig. 1e show that the fastening device 1 according to the invention also comprises at least one fastening element 1.4 which can be mounted on one end 3.1 of an interchangeable watch strap 3. Such a tie element 1.4 comprises a slot 1.4.1 having a shape complementary to the shape of the retaining bar 1.2, so that the retaining bar 1.2 can cooperate with the one or more tie elements 1.4, depending on the position along said longitudinal axis, to allow fixing of said interchangeable watch strap 3 on the watch case 2 or removal of said interchangeable watch strap 3 from the watch case 2.

In particular and as can be seen in fig. 2d, a complementary shaped slot 1.4.1 on each fastening element 1.4 is formed by a groove 1.4.1.1, the height of which corresponds substantially to the reduced thickness 1.2.1 of the retaining bar 1.2. This groove 1.4.1.1 allows, in the actuated position of the body 1.1 acting as a push button, the passage and opening of the retaining rod 1.2 into a through slot seat 1.4.1.2, the diameter of which corresponds substantially to the reference thickness 1.2.2 of the retaining rod 1.2, this through slot seat 1.4.1.2 being able to receive the retaining rod 1.2 in the rest position of the body 1.1 acting as a push button. Furthermore, each tie element 1.4 is arranged, for example, by having a drilling 1.4.2 on the end of the tie element 1.4 opposite to the end comprising said slit 1.4.1 and allowing the fixing means 3.2 to be mounted on this end to receive the fixing means 3.2 of the bracelet 3. The fixing element 3.2 may be formed by screwing the stop levers 3.2.1, 3.2.2, by spring stop levers, by screws or any other suitable element. The fastening element 1.4 itself is preferably and as shown in the drawings implemented by a joint (plot) which is substantially cuboid and which is able to receive a screw stop at its end opposite the end comprising the slit 1.4.1.

It is still to be noted that, in view of the above description of the preferred embodiment of the quick fastening device 1 according to the invention, other alternative embodiments of such a device are within the ability of the person skilled in the art, without the need to describe all these embodiments in detail. For example, it is clear that the spring 1.3, arranged substantially parallel to said retaining bar 1.2, can be fixed inside the watch case 2 and acting on said free end of the pin 1.1.1 mounted on the body 1.1, instead of being mounted on this pin 1.1.1 and acting on the watch case 2. Likewise, the body 1.1 may not have the pin 1.1.1, so that the spring 1.3 is mounted directly on said retaining bar 1.2, even if this configuration is less preferred, since, in addition to the mounting for the spring 1.3, the pin 1.1.1 allows to guide the body 1.1 and to stabilize it in its translational movement. In general, the shape of the body 1.1 serving as a push button can be adapted to the desired shell in its outer shape and in a geometry allowing its movement and guidance.

Furthermore, the holding rods 1.2 can also be arranged differently. In fact, it is clear to the person skilled in the art that, as described above, a guide land 1.2.1.1 of a given length at least one predetermined position along the longitudinal axis of the retaining bar 1.2 forms only one possibility of implementing one of several other possibilities along its longitudinal axis with a predetermined position of reduced thickness 1.2.1 relative to the reference thickness 1.2.2 that the rest of the retaining bar 1.2 has. In alternative further embodiments, it is also possible to implement these predetermined positions along the longitudinal axis of the retaining rod 1.2 with a reduced thickness 1.2.1 by means of a cylindrical rod section which nevertheless has a smaller diameter than the rest of the retaining rod 1.2, by means of a rod section with a square, hexagonal cross section, so that the thickness of this part of the retaining rod 1.2 is smaller than the reference thickness of the rest of the retaining rod 1.2 at least in a particular orientation, all these further variants not being shown in the figures. These explanations also make the arrangement of the two guide flanks 1.2.1.1, which are located on opposite sides and parallel to each other, at each of said predetermined positions of the particularly preferred retaining bar 1.2 clearer, since, in addition to the simplicity of manufacture of such a bar body, this also allows to define a specific orientation, i.e. a direction perpendicular to the plane of the guide flanks 1.2.1.1, which should have a normal in the plane of the slot 1.4.1 of the tie element 1.4, to allow the interchangeable bracelet 3 to be removed from the quick-action tie device 1 even if the body 1.1 serving as a push-button is actuated. This achieves an additional safety protection against any accidental removal of the bracelet 3. Furthermore, depending on the arrangement of the interchangeable watch strap 3 and thus also on the number of fastening elements 1.4 desired, the retaining bar 1.2 will be fitted at one, two, three or more predetermined positions at suitable lengths along the longitudinal axis with these portions of reduced thickness 1.2.1.

Likewise, the fastening element 1.4 may take a considerably different shape without the device leaving the scope of the invention. In the case of interchangeable watch straps 3 made of mutually articulated elements made of metal, so as to be similar to a conventional metal watch strap, each tie element 1.4 is preferably implemented by means of a joint, substantially cubic, as shown in the attached figures. In this case, it is only necessary to mount the respective end of the bracelet 3 on the end of the joint opposite to the end comprising the slot 1.4.1, for example by inserting the screw-on bar 3.2.1 into the bore 1.4.2 and fixing the bar 3.2.1 by means of the nut 3.2.2, as schematically shown on fig. 1 c. Alternatively, the fastening element 1.4 may be implemented by a single piece, substantially T-shaped or H-shaped, the foot of the T-shaped piece, respectively one side of the H-shaped piece, forming the end of the fastening element 1.4 comprising the slit or slits 1.4.1, while the stem of the T-shaped piece, respectively the other side of the H-shaped piece, forms the opposite end comprising a hollow portion capable of receiving the spring catch stem. These alternative embodiments are particularly suitable for fastening interchangeable watch straps 3 made of leather, rubber or synthetic material, which are equipped with the usual snap-catch levers on the quick fastening device 1 according to the invention. Thus, the quick fastening device 1, comprising the body 1.1 acting as a push-button, the retaining bar 1.2, the spring 1.3 and one or more fastening elements 1.4 as proposed, forms a firm, reliable, aesthetic and easy to manufacture and use connection between the watch case 2 and the interchangeable bracelet 3, which is moreover quite flexible in its arrangement to adapt to watch cases of various shapes, and in particular to watch bracelets of various types.

As briefly mentioned above, the present invention relates to a corresponding case 2 for a watchband, which can be fitted with a quick fastening device 1 as described above. Fig. 1c shows that such a watch case 2 generally comprises a case 2.1, the opposite sides of which are arranged to receive interchangeable watch straps. In particular, the casing 2.1 comprises, on each of the two opposite (oppos) sides, a housing 2.1.2 able to receive the body 1.1, the retaining bar 1.2 and the spring 1.3 of said quick fastening device 1, and at least one hollow 2.1.3 able to receive the fastening element or elements 1.4 of said quick fastening device 1. Said housing 2.1.2, which can receive the body 1.1, the holding rod 1.2 and the spring 1.3, is parallel to the plane of the watch case 2 and has an elongated overall shape, the longitudinal axis of which is parallel to the longitudinal axis of the spring catch lever, which is common in watch cases. The first portion of the socket 2.1.2 for receiving the body 1.1 is larger than the second portion of the socket 2.1.2 for receiving the retaining rod 1.2. This second part passes through the casing body 2.1 in its entirety and has a shoulder which forms a support for the end element 1.2.3 of the retaining rod 1.2, so that the tie-down device 1, once mounted in the housing body 2.1.2 of the casing body 2.1, is safely protected in this housing 2.1.2, while allowing a translational movement of the body 1.1 after the action of the user, as is schematically shown on fig. 1 e. The exact shape of the pocket 2.1.2 may vary and of course corresponds to the shape of the body 1.1 and the retaining rod 1.2.

Furthermore, the body 2.1 of such a watch case 2 comprises at least one hollow 2.1.3 capable of receiving the one or more tie elements 1.4, each hollow 2.1.3 being oriented substantially perpendicularly with respect to the housing 2.1.2 and opening into the housing to provide access to the movable retaining bar 1.2. The position of the hollow portions 2.1.3 is chosen such that, in the actuated position of the body 1.1, each reduced thickness 1.2.1 portion of the retaining rod 1.2 appears entirely in the respective hollow portion 2.1.3, whereas, in the rest position, a portion of the retaining rod 1.2 having the reference thickness 1.2.2 appears in the respective hollow portion 2.1.3. It is clear that the number of hollow portions 2.1.3 formed in the case body 2.1 depends on the number of desired tie elements 1.4 or on the number of predetermined positions of the reduced thickness 1.2.1 portion on the retaining bar 1.2, which in turn depends mainly on the desired arrangement of the interchangeable band 3 to be tied to the watch case 2. It is evident that the above-described variants of the members 1.1, 1.2, 1.3, 1.4 forming the rapid tie device 1 can be combined according to and according to the specific constraints imposed in the specific case of the case 2 and of the interchangeable bracelet 3.

Finally, the invention also relates to an interchangeable bracelet 3 arranged to be mounted on a quick fastening device 1 as described above. As mentioned above, the bracelet can be made of various materials, for example of any type of metal, such as steel, gold, titanium or aluminium, leather, rubber, or other synthetic materials, such as plastic, the appearance of the interchangeable bracelet 3 being chosen as desired. In order to be suitable for use in any combination with the quick fastening device 1 according to the invention, it is only necessary that, as can be seen, for example, in fig. 1c and 1e, the corresponding bracelet has a suitable fixing element 3.2 on the end intended to be fastened to the watch case 2. The fixing element may for example consist of a screw stop 3.2.1 comprising a nut 3.2.2, a spring stop, a screw or any other similar element.

In view of the above detailed description of the structure of the quick-fastening device 1 according to the invention, or of the structure of the corresponding watch case 2 and interchangeable watch band 3, the operation of the device is easily understood by means of figures 3a to 3d, which figures 3a to 3d schematically show, by means of a side view and a longitudinal section, the two main operating conditions of the device, namely when the device is in its rest position and its actuated position.

Fig. 3a is a side view of the quick fastening device 1 according to the invention, respectively the corresponding watch case 2 and interchangeable watch strap 3, in its assembled state, when the quick fastening device 1, in particular the body 1.1 serving as a push-button, is in its rest position, and fig. 3b is a longitudinal section through the quick fastening device 1 along the line II-II indicated in fig. 3 a. These figures show, in particular on the area B of fig. 3B, that the edge surface 1.2.1.1, respectively generally the portion of the retaining rod 1.2 with the reduced thickness 1.2.1, is at least partially offset with respect to the slot 1.4.1 arranged on the fastening element 1.4 when the body 1.1 serving as the push button is in the rest position. The bracelet 3 can be exchanged so as to be rigidly connected to the watch case 2 by means of the quick fastening device 1, with a certain freedom of articulation around the longitudinal axis of the retaining bar 1.2.

Fig. 3c is a side view similar to fig. 3a of the quick fastening device 1, respectively the corresponding watch case 2 and interchangeable watch strap 3, when the quick fastening device, in particular the body 1.1 serving as a push-button, is in its actuated position. Fig. 3d is a longitudinal section through the quick-action fastening device 1 along the line III-III indicated in fig. 3c, the spring 1.3, not visible in this figure, being compressed after the user has actuated the body 1.1, thereby displacing the retaining rod 1.2 inwardly of the housing 2.1 in the recess 2.1.2. In this position, when the body 1.1 serving as a push-button is actuated, the facets 1.2.1.1, respectively the portions of the holding rod 1.2 generally having the reduced thickness 1.2.1, are aligned with the slits 1.4.1 of said fastening elements 1.4, as can be seen in particular on the region D of fig. 3D. The arrow E indicated in the figure indicates that the body 1.1 is actuated.

In the preferred embodiment shown in the drawings, the user can thus orient interchangeable watch band 3 in the particular orientation mentioned above, i.e. in a direction such that: the direction perpendicular to the plane of the guide arris 1.2.1.1 is substantially aligned with the normal on the plane of the slit 1.4.1 of the tie element 1.4 to release the interchangeable watch strap 3 and thus allow the interchangeable watch strap 3 to be removed from the quick tie device 1, respectively from the watch case 2, and optionally to be tied to the watch case 2 or another interchangeable watch strap 3. During manufacture, the guide rib 1.2.1.1 has the required orientation relative to the slot 1.4.1 of the fastening element 1.4 by having the orientation, as in a predetermined position of the bracelet 3 relative to the watch case 2, of the slot 1.4.1 relative to the fastening element 1.4, by means of the first indexing rib located on the body 1.1 and the second indexing rib 1.2.1.2 on said end of the retaining bar 1.2 described above, since this predetermined position is visible to the user-the retaining bar 1.2 can be mounted on the body 1.1. As schematically indicated by the arrow C on fig. 3C, the longitudinal axis of the bracelet is preferably parallel to a portion of the watch case, for example to the upper surface of the lateral portion of the case body 2.1 for the integrated body 1.1, in the required orientation allowing the removal of the bracelet or the tie-down top strap. The designer can thus select an additional safety criterion preventing any accidental removal of the bracelet 3 by correspondingly adapting the orientation angle between the interchangeable bracelet 3 and the watch case 2, which allows the upper bracelet 3 to be removed and tied. This measure reinforces the arrangement described above with respect to the force of the prestressing spring 1.3 and by integrating the body 1.1 serving as a push button in the housing 2.1 while aligning the outer surfaces 1.1.2, 2.1.1 of the body 1.1 with the housing 2.1. Thus, the disengagement of the interchangeable bracelet 3 is only produced after the user presses on the body 1.1 when the user orients the bracelet 3 at a predetermined angle with respect to the case 2, whereas the accidental actuation of the body 1.1 integrated in the case 2.1 is unlikely, since the spring 1.3 restores and holds the body 1.1 or the mobile retaining bar 1.2 in the rest position, for which the particular orientation of the bracelet 3 with respect to the case 2 is necessary, at least in a preferred embodiment of the device, the unintentional or accidental disengagement of the bracelet 3 from the case 2 can be almost excluded. In other, less preferred embodiments of the device, for example comprising cylindrical swivelling levers 1.2 with two different diameters, it is not necessary to specifically orient the bracelet in order to remove it or to tie it down.

The quick fastening device according to the invention can comprise many variants, being structurally strong and relatively simple with respect to the prior art and retaining small dimensions. Due to the less complex structure of the device and the smaller space occupied by it compared with similar devices of the prior art, the device is very easy to implement industrially, allowing to reduce the production costs of such quick-fastening devices, respectively of watches equipped with such devices. Furthermore, the device allows for a simple, safe and reliable use. In fact, it is clear that the quick fastening device comprising the features described above is actuated solely by pressing, alternatively orienting the interchangeable watch strap in a specific direction to allow the removal of the watch strap or the fastening of the watch strap, while accidental actuation of the push-button, respectively the unintentional or accidental detachment of the interchangeable watch strap, can be almost excluded. The guiding of the translational movement by the body forming the push-button and the two rods tied to the body and the absence of complex kinematics make the operation of the device reliable. The device has the important advantage of being easier to integrate in existing timepieces than the systems of the prior art, without requiring excessive adjustments or significant modifications to the design of these timepieces. In summary, the quick fastening device according to the invention allows the user to intuitively replace the interchangeable bracelet fastened to the watch case, according to his preferences and/or considering the conditions of use of his watch, without having to have tools or particular skills.

Claims (16)

1. Quick-fastening device (1) for an interchangeable bracelet (3) for a watch, comprising a body (1.1) which acts as a push-button and is slidably housed in a watch case (2), said body (1.1) carrying a retaining bar (1.2) arranged parallel to the plane of said watch case (2) and in the sliding direction of said body (1.1) so that said body (1.1) can move parallel to the longitudinal axis of said retaining bar (1.2),

characterized in that said body (1.1) cooperates with a spring (1.3) arranged substantially parallel to said retaining rod (1.2) and exerting a prestress which restores said body (1.1) acting as a push button to a rest position;

said retaining bar (1.2) having a particular shape, having, in at least one predetermined position along its longitudinal axis, a reduced thickness (1.2.1) reduced with respect to a reference thickness (1.2.2) possessed by the remainder of said retaining bar (1.2);

and comprising at least one fastening element (1.4) able to be mounted on one end (3.1) of the interchangeable bracelet (3) and comprising a slot (1.4.1) of complementary shape to that of the retaining bar (1.2), the retaining bar (1.2) being able to cooperate, according to its position along the longitudinal axis, with the at least one fastening element (1.4) to allow the interchangeable bracelet (3) to be fastened to or removed from the watch case (2).

2. Quick fastening device according to claim 1, characterized in that the retaining lever (1.2) comprises a guide land (1.2.1.1) in at least one predetermined position, such that, when the body (1.1) serving as a push button is actuated, the guide land (1.2.1.1) is aligned with the slot (1.4.1) of the at least one fastening element (1.4), whereas, when the body (1.1) serving as a push button is in its rest position, the guide land (1.2.1.1) is at least partially offset with respect to the slot (1.4.1).

3. Quick fastening device according to claim 1, characterized in that the retaining lever (1.2) comprises guide lands (1.2.1.1) in two predetermined positions, such that, when the body (1.1) serving as a push button is actuated, the guide lands (1.2.1.1) are aligned with the slit (1.4.1) of the at least one fastening element (1.4), and, when the body (1.1) serving as a push button is in its rest position, the guide lands (1.2.1.1) are at least partially offset with respect to the slit (1.4.1).

4. Quick fastening device according to claim 1, characterized in that said retaining bar (1.2) comprises an end element (1.2.3) mounted on the free end, opposite to the end of the retaining bar fixed on said body (1.1) acting as a push-button and allowing to protect said body (1.1) from any disengagement from said watch case (2).

5. Quick fastening device according to claim 1, characterized in that the spring (1.3) arranged substantially parallel to the retaining bar (1.2) is fixed on the free end of a pin (1.1.1) mounted on the body (1.1) acting as a push button and arranged parallel to the retaining bar (1.2).

6. Quick fastening device according to any one of claims 1 to 5, characterized in that the spring (1.3) arranged substantially parallel to the retaining bar (1.2) is a helical spring.

7. Quick fastening device according to any one of claims 1 to 5, characterized in that the complementary shaped slot (1.4.1) on each fastening element (1.4) is formed by a groove (1.4.1.1) having a height corresponding to the reduced thickness (1.2.1) of the retaining bar (1.2), the groove (1.4.1.1) enabling the retaining bar (1.2) to pass and open, in the actuated position of the body (1.1) acting as a push button, to a through slot seat (1.4.1.2) having a diameter corresponding to the reference thickness (1.2.2) of the retaining bar (1.2), the through slot seat (1.4.1.2) being able to receive the retaining bar (1.2) in the rest position of the body (1.1) acting as a push button.

8. Quick fastening device according to any one of claims 1 to 5, characterized in that each fastening element (1.4) is arranged to receive a fixing part (3.2) of a bracelet (3), said fixing part (3.2) being mounted on the end of said fastening element (1.4) opposite to the end thereof comprising said slit (1.4.1).

9. Quick fastening device according to claim 8, characterized in that the fixing part (3.2) is selected in the group of fixing elements comprising screw bars (3.2.1, 3.2.2), spring bars, screws.

10. Quick fastening device according to any one of claims 1 to 5, characterized in that said at least one fastening element (1.4) is made by a substantially square-shaped joint able to receive a screwing bar on its end opposite to the end comprising said slit (1.4.1).

11. Quick fastening device according to any one of claims 1 to 5, characterized in that the at least one fastening element (1.4) is made by a single piece substantially T-shaped, the foot of which forms the end of the fastening element (1.4) comprising the slit (1.4.1), while the crossbar of the single T-shaped piece forms the opposite end and comprises a hollow capable of receiving a spring bar.

12. Quick fastening device according to any one of claims 1 to 5, characterized in that said body (1.1) acting as a push-button is arranged so as to have, in said rest position, an outer surface (1.1.2) aligned and coincident with respect to an outer surface (2.1.1) of said watch case (2) for integrating said body.

13. A watch case (2) for a watch, comprising a case body (2.1) two opposite sides of which are arranged to receive interchangeable watch straps,

characterized in that said shell (2.1) comprises, on each of said two opposite sides, a housing (2.1.2) able to receive the body (1.1), the retaining bar (1.2) and the spring (1.3) of the quick tie-down device (1) according to any one of claims 1 to 12, and at least one hollow (2.1.3) able to receive said at least one tie-down element (1.4) of the quick tie-down device.

14. Watch case (2) according to claim 13, characterised in that said housing (2.1.2) able to receive the body (1.1), the retaining bar (1.2) and the spring (1.3) is oriented substantially perpendicularly with respect to said at least one hollow (2.1.3) able to receive said at least one tie element (1.4).

15. An interchangeable watch strap (3), characterized in that it is arranged to be mounted on a quick fastening device (1) according to any one of claims 1 to 12.

16. The interchangeable watch band (3) according to claim 15, made in a material chosen in the group comprising: metals, such as steel, gold, titanium or aluminium, leather, rubber, synthetic materials, such as plastics.