Breguet overcoil balance spring made of silicon-based material
AssigneeMontres Breguet S.A.
InventorsAlain Zaugg, Christophe Bifrare, Sacha Vorpe, Jean-Philippe Thiebaud, Marc Lippuner
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Abstract
The invention relates to a silicon-based Breguet overcoil balance spring (1, 31) that includes a hairspring (3, 33) made integral coaxially with a collet (5, 35), a terminal curve (7, 37) and an elevation device (9, 39) between the outer coil (15, 45) of the hairspring and the terminal curve. According to the invention, the balance spring has two single parts secured to each other to increase the development precision of the balance spring. The invention also relates to the method of manufacturing the balance spring. The invention concerns the field of timepiece movements.
Claims25
A Breguet overcoil balance spring made of silicon-based material, wherein the balance spring includes:
- (a) a hairspring made integral coaxially with a collet so as to form a hairspring-collet assembly;
- (b) a terminal curve;
- and
- (c) an elevation device disposed between an outer coil of the hairspring and the terminal curve, wherein the elevation device includes at least one first post that connects one end of the outer coil to one end of the terminal curve integral with the hairspring-collet assembly.
A Breguet overcoil balance spring made of silicon-based material, wherein the balance spring includes:
- (a) a hairspring made integral coaxially with a collet so as to form a hairspring-collet assembly;
- (b) a terminal curve;
- and
- (c) an elevation device disposed between an outer coil of the hairspring and the terminal curve, wherein the elevation device includes one or more posts that connect one end of the outer coil to one end of the terminal curve made in a single piece with the terminal curve, and wherein each post is secured in a recess made in an end of the hairspring-collet assembly.
A method of manufacturing a Breguet overcoil balance spring, wherein the method includes the following steps:
- (a) providing a first substrate that includes a top layer and a bottom layer that are silicon-based and connected to each other via an intermediate layer;
- (b) selectively etching at least one cavity in the top layer in order to define a terminal curve;
- (c) selectively etching at least one cavity in the bottom layer in order to define at least one post that connects one end of the terminal curve;
- (d) providing a second substrate that has a silicon-based layer;
- (e) selectively etching at least one cavity in the layer of the second substrate in order to define a collet made integral and coaxially with a hairspring whose outer coil includes at least one recess;
- and
- (f) assembling the at least one post in the at least one recess to form a Breguet overcoil balance spring.
A method of manufacturing a Breguet overcoil balance spring, wherein the method includes the following steps:
- (a) providing a first substrate that includes a top layer and a bottom layer that are silicon-based and connected to each other via an intermediate layer;
- (b) selectively etching at least one cavity in the top layer in order to define a collet made in a single piece coaxially with a hairspring;
- (c) selectively etching at least one cavity in the bottom layer in order to define at least one post that connects an outer coil of the hairspring;
- (d) providing a second substrate that has a silicon-based layer;
- (e) selectively etching at least one cavity in the layer of the second substrate to define a terminal curve, wherein one end of the terminal curve has at least one recess;
- and
- (f) assembling the at least one post in the at least one recess to form a Breguet overcoil balance spring.
Dependencies are inferred from the claim text.