Timepiece regulating member comprising an index-assembly system provided with locking means
A regulating member for a horological movement including an inertial mass, for example a balance, a balance spring, and an index-assembly system for adjusting the rate of the balance spring, the index-assembly system including a stud-holder including a first portion and a second portion, the first portion being movable relative to the second portion, wherein the regulating member includes locking device configured to block the second portion of the stud-holder in one position with respect to a plate of the movement.
1 . A regulating member for a horological movement comprising:
a balance, a balance spring, and an index-assembly system for adjusting a rate of the balance spring, the index-assembly system comprising a stud-holder comprising a first portion comprising a first stud and a second portion comprising a second stud, the first portion being movable relative to the second portion to be able to set a rate of the regulating member, wherein the regulating member comprises a locking device configured to block the second portion of the stud-holder in one position with respect to a plate of the movement,
wherein the balance spring comprises a coiled strip and an adjustment device for adjusting a rigidity of the balance spring fitted with a resilient element arranged in series with the coiled strip, the stud-holder being mechanically linked to the resilient element,
wherein the adjustment device comprises a prestressing device for applying a variable force or torque on the resilient element, and
wherein the resilient element and the prestressing device are arranged between the first stud and the second stud, the first stud being movable relative to the second stud to actuate the prestressing device, a movement of the first stud modifying the rigidity of the balance spring.
2 . The regulating member according to claim 1 , wherein the locking device comprises an eccentric mounted on a balance bridge of the regulating member.
3 . The regulating member according to claim 2 , wherein the second portion comprises a protrusion having a circle-arc shape cooperating with the eccentric.
4 . The regulating member according to claim 1 , wherein the locking device comprises a locking plate and a locking screw for assembling the locking plate on the second portion and locking the second portion in the one position.
5 . The regulating member according to claim 4 , wherein the locking plate has a shape cooperating on one side with a balance bridge of the regulating member, and on an other side with a bearing of the regulating member to block the second portion.
6 . The regulating member according to claim 4 , wherein the locking screw is arranged so as to cross the locking plate to be screwed in a balance bridge of the regulating member.
7 . The regulating member according to claim 1 , wherein the index-assembly system comprises a cam and a spring, exerting a force between the first portion and the second portion to hold an arm of the first portion against the cam.
8 . The regulating member according to claim 1 , wherein the prestressing device includes a lever connected to the resilient element, the first stud being secured to a free end of the lever.
9 . The regulating member according to claim 8 , wherein the prestressing device includes a semi-rigid structure, the lever being connected to the semi-rigid structure.
10 . The regulating member according to claim 1 , wherein the resilient element is connected to a rigid support, the second stud being secured to the rigid support.
11 . The regulating member according to claim 1 , wherein the first portion and the second portion are superimposed.
12 . The regulating member according to claim 1 , wherein the first portion is movable in rotation relative to the second portion.
13 . A horological movement, comprising the regulating member according to claim 1 .
14 . A timepiece, comprising the horological movement according to claim 13 .
15 . The timepiece according to claim 14 , wherein the timepiece is a watch.