Horological assembly comprising a balance spring and a stud
An assembly ( 1 ) for attaching a free end ( 8 ) of an outer last coil ( 10 ) of a balance spring ( 12 ) for a horological movement, this attachment assembly ( 1 ) including a stud ( 2 ) and a blocking element ( 14 ), the stud ( 2 ) being provided with a groove ( 6 ) in which the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ) is engaged, the blocking element ( 14 ) also being engaged in the groove ( 6 ), in contact with the outer last coil ( 10 ) of the balance spring ( 12 ), the attachment assembly ( 1 ) further including a clamping member ( 16 ) which presses the blocking element ( 14 ) against the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ), such that the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ) is immobilised in the groove ( 6 ) of the stud ( 2 ).
1 . An assembly ( 1 ) for attaching a free end ( 8 ) of an outer last coil ( 10 ) of a balance spring ( 12 ) for a horological movement, the attachment assembly ( 1 ) comprising a stud ( 2 ) and a blocking element ( 14 ),
the stud ( 2 ) being provided with a groove ( 6 ) in which the balance spring ( 12 ) is engaged at a point along its length, and a bottom ( 46 ) that is separated by the groove ( 6 ) in a first direction (Z) that is perpendicular to a plane in which a winding of the coils lies,
the blocking element ( 14 ) being elastically engaged with the stud ( 2 ) in the groove ( 6 ), and being in contact with the balance spring ( 12 ),
the attachment assembly ( 1 ) further comprising a clamping member ( 16 ) which presses the blocking element ( 14 ) in the first direction (Z) against the balance spring ( 12 ) and the bottom ( 46 ), such that the balance spring ( 12 ) is immobilised in the groove ( 6 ) of the stud ( 2 ) in the first direction (Z).
2 . The attachment assembly ( 1 ) according to claim 1 , wherein the balance spring ( 12 ) is engaged within the groove ( 6 ) of the stud ( 2 ) via the free end ( 8 ) of its outer last coil ( 10 ).
3 . The attachment assembly according to claim 2 , wherein the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ) is immobilised by mechanical clamping and blocking in a direction perpendicular to the plane in which this free end ( 8 ) of the balance spring ( 12 ) extends.
4 . The attachment assembly ( 1 ) according to claim 1 , wherein the groove ( 6 ) extends from an outer wall ( 4 ) of the stud ( 2 ) towards the inside thereof.
5 . The attachment assembly ( 1 ) according to claim 4 , wherein the groove ( 6 ) has a height and the blocking element ( 14 ) a thickness such that, once the blocking element ( 14 ) is engaged in this groove ( 6 ), enough space remains to be able to engage the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ) within the groove ( 6 ).
6 . The attachment assembly ( 1 ) according to claim 5 , wherein the space in which the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ) is engaged extends between the blocking element ( 14 ) and the bottom ( 46 ) of the groove ( 6 ).
7 . The attachment assembly ( 1 ) according to claim 6 , wherein the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ) terminates in a plate ( 50 ) which is attached to this free end ( 8 ) or which is made in one piece with this free end ( 8 ).
8 . The attachment assembly ( 1 ) according to claim 1 , wherein a hole ( 22 ) in which the clamping member ( 16 ) is engaged is formed in the stud ( 2 ) such that the clamping member ( 16 ) extends into the groove ( 6 ) and presses against the blocking element ( 14 ), pressing the latter against the free end ( 8 ) of the outer last coil ( 10 ) of the balance spring ( 12 ).
9 . The attachment assembly ( 1 ) according to claim 8 , wherein the clamping member ( 16 ) is a threaded rod ( 18 ) and wherein the hole ( 22 ) is tapped.
10 . The attachment assembly ( 1 ) according to claim 8 , wherein the blocking element ( 14 ) is a clamp ( 28 ) provided with two jaws ( 30 a , 30 b ) connected to one another at a distal end ( 32 a , 32 b ), these two jaws ( 30 a , 30 b ) defining therebetween a space ( 34 ) that is open on their proximal end ( 36 a , 36 b ) side.
11 . The attachment assembly ( 1 ) according to claim 10 , wherein the stud ( 2 ) comprises a wall ( 38 ) which delimits the groove ( 6 ).
12 . The attachment assembly ( 1 ) according to claim 11 , wherein the inner face of one of the jaws ( 30 a , 30 b ) of the clamp ( 28 ) has a surface ( 40 ) which extends away from the wall ( 38 ) of the stud ( 2 ) in the direction of engagement of the clamp ( 28 ) on the stud ( 2 ).
13 . The attachment assembly ( 1 ) according to claim 11 , wherein the inner faces of the jaws ( 30 a , 30 b ) of the clamp ( 28 ) are provided with recesses ( 42 a , 42 b ), the shapes of the recesses are complementary and match a shape of the wall ( 38 ), allowing the clamp ( 28 ) to grip the wall ( 38 ) and hold it.
14 . The attachment assembly ( 1 ) according to claim 1 , wherein the balance spring ( 12 ) is configured to be immobilised in the groove ( 6 ) of the stud ( 2 ) in the first direction (Z) without any adhesive.
15 . The attachment assembly ( 1 ) according to claim 1 , wherein the blocking element ( 14 ) is a clamp ( 28 ) provided with two jaws ( 30 a , 30 b ) and formed with elasticity, these two jaws ( 30 a , 30 b ) defining therebetween a space ( 34 ) that is open on their proximal end ( 36 a , 36 b ) side, and
wherein the two jaws ( 30 a , 30 b ) elastically are engaged with the stud ( 2 ) in the groove ( 6 ).
16 . The attachment assembly ( 1 ) according to claim 15 , wherein the stud ( 2 ) comprises a wall ( 38 ) which delimits the groove ( 6 ) along the first direction (Z) between the stud ( 2 ) and the bottom ( 46 ), and
wherein the two jaws ( 30 a , 30 b ) are engaged with the wall ( 38 ) of the stud ( 2 ).