This application claims priority from European Patent Application No. 07105765.7 filed Apr. 5, 2007, the entire disclosure of which is incorporated herein by reference
The present invention concerns bracelets with hinged or articulated links, particularly watch bracelets. In other words, the invention concerns bracelets whose links are assembled using pins defining pivoting axes for the links. The pins each pass through at least two partially interlocking or overlapping links.
The bracelet pins are inserted into cylindrical passages arranged in the links. In order to ensure assembly of the links, the various pins must be held in place, i.e. to prevent the pins moving transversely to the bracelet once the bracelet links are assembled. Various techniques are known to those skilled in the art for fixedly holding the pins in the respective bracelet passages. Moreover, particularly in order to adjust the length of the bracelet in accordance with the diameter of the wearer's wrist, it is desirable to be able to remove or add at least one link without damaging the bracelet and in an efficient manner, if possible by the user himself.
The present invention proposes in particular providing a reversible system for assembling the links of a bracelet with hinged links, the assembly being provided such that at least one link can easily be added to or removed from the bracelet in order to vary its length.
A watch bracelet formed of several links hinged by means of alternately arranged long pins and short pins is known from GB Patent No. 2 227 155. Each long pin is permanently secured by the first end thereof to a first link. This pin is secured in a reversible manner by the second end thereof to a second link. A screw that partially passes through the passage provided in the second link to allow the second end of the pin to pass forms the reversible securing device. The second end of the pin has a circular groove, which is penetrated by the securing screw. Thus, using a screwdriver, it is possible to assemble the bracelet links by screwing in small screws which block the long pins.
The bracelet link assembly device proposed in GB Patent No. 2 227 155 is advantageous in that the assembly system is relatively simple and allows links to be added or removed by unscrewing the securing screws provided at the second ends of the long pins. However, this solution has some drawbacks. First of all, the securing screws are very small. A watchmaker is trained to screw and unscrew such small screws, but this is relatively difficult for a mere user. Because of their dimensions, the securing screws are easily lost as soon as they come out of the threaded holes of the second links. Moreover, when the bracelet is worn these screws may become partially unscrewed with the risk of one of the long pins being released and the bracelet then being partially dismantled. For a wristwatch, this solution is to be avoided at all costs.
It is therefore an object of the present invention to propose a bracelet with hinged links assembled in a simple and efficient manner while ensuring that none of the bracelet elements can be lost particularly when alterations are made to the length of the bracelet by adding or removing some links. It is another object of the invention to provide a reversible link assembly device wherein the securing element cannot be loosened by stresses exerted on the bracelet when it is being worn on the wrist.
The invention therefore concerns a bracelet formed of a plurality of links assembled such that at least a first link of this plurality of links can be separated from the others, this first link being assembled with at least a second link by means of a transverse pin, which is associated with means for locking its transversal position in the bracelet. These locking means are arranged in a reversible manner to allow the pin to be released and the first and second links to be separated. The bracelet is characterized in that said locking means include a locking element which ensures the transversal position of the pin in a first angular position of the locking element and releases the pin along the longitudinal direction thereof in a second angular position, the locking element being arranged in one of the first and second links so that it can be rotated about its axis of rotation, and in that the locking element has a non cylindrical portion, relative to said axis of rotation, one external part of which is located at least partially in a recess arranged at the cylindrical surface of the pin when the locking element is in said first angular position, this non cylindrical portion remaining opposite said pin without penetrating said recess when the locking element is in said second angular position.
According to a particular embodiment of the invention, a truncated cylinder portion forms the non-cylindrical portion of the locking element at least along a plane parallel to the axis of rotation of the locking element.
Preferably, the recess provided in the pin is formed by a groove, in the surface of the pin, centered on the longitudinal axis of the pin.
In a preferred embodiment, the first position of the locking element is ensured by means for locking the angular position thereof, a user being able to activate these locking means in order to allow him to rotate the locking element from the first position to the second position thereof in which the pin is released.
The first position of the locking element thus corresponds to a closed position or locking position of the pin, whereas the second position corresponds to an open position or detached position of the pin and the link in which the locking element is arranged.
According to a preferred variant, the locking element is held in a cavity of the link in which it is arranged by a structure forming a stop member on the side of the external surface of the link.
According to the invention, the locking element forms a sort of lock or cam which remains associated with the link in which it is arranged. This locking element cannot thereof be lost since it cannot be separated from the link concerned.
Other features and advantages of the present invention will also appear from the following detailed description, made with reference to the annexed drawings, given by way of non limiting example, in which:
a and 3b are cross-sections of
a and 4b are cross-sections respectively along two orthogonal planes showing the reversible locking device, shown in
a and 5b are respectively side and top views of an external ring of the locking device shown in
a, 6b and 6c show a locking element in various views, and
With reference to
In the variant shown in
Locking device 10 essentially includes three elements, one of which is associated with a recess made in pin 8. Before explaining the operation of the reversible locking device, we will described each of the constituent parts of the device.
First of all, pin 8 includes a recess 22 defined by a circular groove made in the cylindrical surface of the pin and centered on the longitudinal axis 20 thereof.
Locking device 10 includes three elements 12, 14 and 16 arranged in a cavity 18 provided in particular in link 4 for locking the transversal position of pin 8 in a reversible manner, forming an articulated assembly between link 4 and the adjacent link 5.
Locking element 12 includes a circular head 24, visible and accessible from the back face of link 4. This head includes a central groove 26 for actuating the locking device in rotation using a screwdriver. Next, element 12 includes a central body formed by a non-cylindrical portion. A truncated cylinder portion forms this non-cylindrical portion 28 at least along a plane parallel to the axis of rotation 30 of element 12. In the present case, the cylinder is machined along two parallel planes defining two diametrically opposite plane surfaces 33 and 34. These surfaces 33 and 34 are set back relative to the axis of rotation 30 and relative to the two cylindrical surfaces 35 and 36 remaining between these two plane surfaces. The lateral wall of the non-cylindrical portion is thus formed of four distinct surfaces, namely set back two plane surfaces and two cylindrical surfaces defining two external parts 35 and 36 of the locking element. Finally, this element 12 includes an end part 40. This end part is circular with a lateral surface whose radius at the center corresponds to that of the external parts 35 and 36. A recess 42 is made in element 12 from the end part 40 to house therein a spring 16 for pressing the element against structure 14 partially closing cavity 18.
It will be noted first of all that, within the scope of the present invention, a single surface 34 set back from another lateral surface 36 relative to axis of rotation 30 is sufficient for the operation of the locking device described here. However, the presence of the two diametrically opposite plane surfaces 33 and 34 facilitates manipulation of the device for a user. In order to ensure that locking element 12 works in association with groove 22 made in pin 8, the non cylindrical portion of the locking element only needs to have a lateral wall that has a maximum distance relative to a first geometrical plane X-X, including axis of rotation 30, which is less than the maximum distance from this lateral wall relative to a second geometrical plane Y-Y also including axis of rotation 30 (see
Structure 14 is used for partially closing aperture 18 in link 4 so as to hold locking element 12 in the cavity. It therefore forms a stop member for two shoulders 37 and 38 of the locking element defined by the external parts 35 and 36 whose radius at the center is greater than the radius of head 24. Structure 14 forms a ring whose central aperture has a radius adjusted to the radius of head 24 of element 12. Structure 14 is formed of an annular base 44 on which two projecting parts 45 and 46 are mounted diametrically opposite relative to the central axis of the structure which is identical to axis of rotation 30 of the locking element. Structure 14 defines two bottom steps 47 and 48 and two top steps 49 and 50. For shoulders 37 and 38 of the locking element, structure 14 thus defines four different angular positions, shifted by 90°. It will be noted that the structure, axially forming a stop member for the locking element, only needs to have two steps at the periphery of the locking element and located at two different levels along the axis of rotation of the locking element. These two steps must be arranged to allow one shoulder of the locking element to be pressed by spring 16 against the bottom step when it is in the closed position, whereas it is pressed against the top step when the locking element is in the open position, such that a user has to exert pressure on the locking element to bring it from the closed position, where the pin is locked, to the open position, where the pin is released.
With reference to
Cavity 18 opens out onto the bottom surface of the link in which it is machined. This cavity 18 thus defines a blind hole in which locking element 12 is arranged with spring 16 placed in its central hole 42. Spring 16 thus pushes element 12 in the direction of the external aperture of cavity 18. To prevent element 12 being able to leave the latter, the annular structure 14 is arranged on the side of the opening of cavity 18 at the periphery of the locking element such that its head 24 is located in the central aperture of structure 14 and that at least one external shoulder of element 12 is stopped against a horizontal surface of structure 14, whatever the angular position of the locking element. More specifically, in the situation where the locking element has an angular position corresponding to the open position of the locking device, as shown in
In order to pass from the open position of
Generally, the means used for locking the pin locking element are formed by the arrangement of a structure in cavity 18 defining at least two steps at the periphery of the locking element, which are located at two different levels along axis of rotation 30 of the locking element, and by a spring 16 used to press one shoulder of the locking element against the bottom step when the locking element has an angular position corresponding to the closed position, i.e. in a position preventing the pin from moving along its longitudinal axis.
It will also be noted that the term “link” used must be understood in the widest sense to include any intermediate element between other links and elements of the bracelet that are not visible on the top thereof.
In another particular embodiment of the invention, a single locking device placed between two close passages is used to lock or release two neighbouring pins respectively arranged in these two passages. Thus, the invention is not limited to the single embodiment shown in the Figures.
Number | Date | Country | Kind |
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07105765.7 | Apr 2007 | EP | regional |