Patent ID: 9285773
Filing Date: 2016-03-15
CPC Classification: G04B

Claim Text:
1. A timepiece movement including at least one combined unit formed of a sprung balance assembly and a pallet lever, said sprung balance assembly including an equipped balance having a balance hub of which is mounted on an equipped staff, said equipped staff includes a roller sleeve which carries an impulse pin and at least one notch, and said roller sleeve being driven onto a roller shoulder of a timepiece balance staff, said staff including, about a main pivot axis: a main shoulder for the radial centring of said balance, and, adjacent to said main shoulder, a first lateral bearing surface extending substantially radially and receiving said balance in axial abutment; a collet shoulder for the radial centring of a balance spring collet comprised in said sprung balance assembly, said collet shoulder and said main shoulder being at a distance from each other and arranged to maintain a distance from each other, said collet being mounted on said collet shoulder, and said balance being mounted on said main shoulder, said staff forming a stepped hub including at both ends thereof, in proximity to end pivots, on the one hand, said roller shoulder, which is adjacent to a first radial shoulder, and on the other hand, said collet shoulder, which is adjacent to a second lateral surface, said first radial shoulder and said second lateral surface defining together a collar, said collar in turn including said main shoulder which is adjacent to said first lateral bearing surface for the axial bearing of said balance, and said first lateral bearing surface facing the same side as said first radial shoulder, and said balance shoulder being separated from said collet shoulder via a peripheral portion forming a seat which forms the largest diameter of said collar and of said staff the balance hub being mounted via a bore comprised in said hub on said main shoulder and also mounted bearing, via a first bearing surface comprised in said balance, on said first lateral bearing surface, said hub being held, on a second surface of said balance axially opposite to said first bearing surface, via a sharp rivet edge resulting from local deformation of a lip of said staff, said balance being confined between said first lateral bearing surface and said sharp rivet edge, the abutment limit of the balance being located on the opposite side to said roller shoulder, and said sleeve being driven in on the opposite side to said balance relative to said sharp rivet edge, said balance spring collet, to which is attached at least one balance spring, being mounted by clamping on said staff, and bearing in abutment on said second lateral surface, and said pallet lever being arranged to cooperate with said impulse pin and said notch, and said pallet lever including a lever whose pivot defines a pallet lever pivot axis parallel to said main axis, said lever carrying a dart in the alignment thereof, and a set of horns arranged to cooperate with said impulse pin as close as possible to said main shoulder, said dart being arranged to cooperate with said notch as far as possible from said main shoulder, and said set of horns being arranged in a substantially parallel plane to a plane defined by said lever and said dart, wherein said movement includes a bottom plate carrying a first pallet stone, and a pallet bridge carrying a second pallet stone, said pallet lever being pivotally guided between said pallet stones, said bottom plate carrying a first shock resistant balance guide member including first means of pivotally guiding said staff about said main axis, and said movement including a balance bar carrying a second shock resistant balance guide member including second means of pivotally guiding said staff about said main axis, said sprung balance assembly is pivotally guided between said shock resistant guide members, and in that said dart is closer than said horns to said shock resistant guide member which is farthest from said balance spring.