Extendable clasp for a bracelet in particular for a watch

Abstract

The present invention concerns a clasp with an extensible buckle for a bracelet enabling the length of the bracelet to be adjusted. This clasp comprises: a central support ( 1 ); a first and second pivoting strip ( 2 a, 2 b ) articulated at the respective ends of the central support ( 1 ) and capable of being closed on the latter; means for closing and opening ( 14, 16, 17, 19, 22 ) the clasp arranged in such a way as to lock the first and second pivoting strip ( 2 a, 2 b ) against the central support ( 1 ) and to unlock said first and second pivoting strip (2 a, 2 b ) of the central support ( 1 ) so they can be extended; at least one first attachment ( 6 a ) solid with the first pivoting strip ( 2 a ), and arranged to be connected to a first strand of the bracelet and a second attachment ( 6 b ) solid with the second pivoting strip ( 2 b ) and arranged to be able to be linked to a second strand of the bracelet. The clasp according to the invention also comprises an attachment body ( 4 ) arranged on at least one of the first and second pivoting strips ( 2 a, 2 b ), the attachment or each first and second attachment ( 6 a, 6 b ) being connected to the corresponding attachment body ( 4 ), which latter is capable of being displaced in the longitudinal direction of the corresponding pivoting strip ( 2 a, 2 b ) to be locked in various positions along said strip ( 2 a, 2 b ).

1 . Clasp with an extensible buckle for a bracelet enabling the length of the bracelet to be adjusted, said clasp comprising:
 a central support ( 1 ),   a first and second pivoting strip ( 2   a,    2   b ) articulated at either end of the central support ( 1 ) and capable of being closed on the latter,   means for opening and closing ( 14 ,  16 ,  17 ,  19 ,  22 ) the clasp arranged in such a way as to lock the first and second pivoting strip ( 2   a,    2   b ) against the central support ( 1 ) and to unlock said first and second pivoting strip ( 2   a,    2   b ) from the central support ( 1 ) so they can be extended,   at least one of a first attachment ( 6   a ) solid with the first pivoting strip ( 2   a ) and arranged so as to be connected to a first strand of the bracelet and a second attachment ( 6   b ) solid with the second pivoting strip ( 2   b ), and arranged so as to be connected to a second strand of the bracelet;
 characterised in that 
   
       the clasp furthermore comprises an attachment body ( 4 ) arranged on at least one of the first and second pivoting strips ( 2   a,    2   b ), the attachment or each first and second attachment ( 6   a,    6   b ) being connected to the corresponding attachment body ( 4 ), which latter is capable of being displaced in the longitudinal direction of the corresponding pivoting strip ( 2   a,    2   b ) to be locked in various positions along said strip ( 2   a,    2   b ). 
     
     
         2 . Clasp according to  claim 1 , characterised in that at least one of the pivoting strips ( 2   a,    2   b ) is provided with an elongated hollow ( 5 ), the corresponding attachment body ( 4 ) being capable of sliding inside the hollow ( 5 ) along the longitudinal edges ( 2 ,  2 ′) of the corresponding pivoting strip ( 2   a,    2   b ), then being locked in translation in one of the various indexed positions in relation to said strip ( 2   a,    2   b ). 
     
     
         3 . Clasp according to  claim 1 , characterised in that the pivoting strip or each pivoting strip ( 2   a,    2   b ) comprises a bolt ( 7 ) arranged to operate in conjunction with the corresponding attachment body ( 4 ), the bolt ( 7 ) being capable of assuming respectively a first and a second axial position so that the attachment body or each attachment body ( 4 ) can be locked in one of the various indexed positions when the bolt ( 7 ) is situated in one of the first and second axial positions, and in such a way that the attachment or each attachment body ( 4 ) can be unlocked in order to be able to slide inside the corresponding hollow ( 5 ) to assume another indexed position when the bolt ( 7 ) is situated in the other of the first and second axial positions. 
     
     
         4 . Clasp according to  claim 3 , characterised in that the bolt ( 7 ) is arranged to cross the longitudinal edges ( 2 ,  2 ′) of the pivoting strip or each pivoting strip ( 2   a,    2   b ) as well as the attachment body ( 4 ) along a perpendicular axis in the direction of displacement of the said body ( 4 ). 
     
     
         5 . Clasp according to  claim 3 , characterised in that the attachment body or each attachment body ( 4 ) comprises an opening ( 8 ), the lower and/or upper edge of the opening ( 8 ) comprising several recesses ( 9   a,    9   b,    9   c ) spaced in the direction of displacement of the attachment body ( 4 ) and in that the bolt ( 7 ) comprises a bulge ( 7   a ) arranged to come to be accommodated in one of the recesses ( 9   a,    9   b,    9   c ) in order to lock the attachment body or each attachment body ( 4 ) in one of the various indexed positions while the bolt ( 7 ) is situated in one of the first and second axial positions. 
     
     
         6 . Clasp according to  claim 1 , characterised in that a pawl ( 10 ) is arranged in at least one of the longitudinal edges ( 2 ,  2 ′) of the pivoting strip or each pivoting strip ( 2   a,    2   b ) to operate in conjunction with several recesses ( 11 ) situated on the corresponding attachment body ( 4 ) in order to pre-position said body ( 4 ) in one of the various indexed positions before displacing the corresponding bolt ( 7 ) from any one of its two axial positions in order to lock said body ( 4 ). 
     
     
         7 . Clasp according to  claim 3  characterised in that the central support ( 1 ) of the clasp comprises two side structures ( 12 ,  12 ′), the internal flanks of which comprise notches ( 13 ) for accommodating any one end of the corresponding bolt ( 7 ) when the first and second pivoting strips ( 2   a,    2   b ) are closed on said support. 
     
     
         8 . Bracelet comprising the clasp according to  claim 1 . 
     
     
         9 . Watch comprising the bracelet according to  claim 8 .