Method of manufacturing a one-piece hairspring
AssigneeMontres Breguet S.A.
InventorsPierre-André Bühler, Marco Verardo, Thierry Conus, Jean-Philippe Thiebaud, Jean-Bernard Peters, Pierre Cusin
Life of this patent
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Abstract
The invention relates to a one-piece hairspring (21, 21′) including, a balance spring (25, 25′) coaxially mounted on a collet (27, 27′), made in the same layer of silicon-based material. According to the invention, the hairspring includes an elevation device (2, 2′) for the outer coil of the balance spring above the layer of silicon-based material so as to improve the concentric development of the hairspring. The invention also relates to a timepiece including a hairspring of this type and the method of manufacturing the same. The invention concerns the field of timepiece movements.
Claims10
A method of manufacturing a one-piece hairspring with a raised terminal curve, the method including the following steps:
- a) providing a substrate including a top layer and a bottom layer of silicon-based materials,
- b) selectively etching at least one cavity in the top layer to form a first portion of an elevation element, made of silicon-based material, for the hairspring with the raised terminal curve,
- c) joining an additional layer of silicon-based material to the etched top layer of the substrate,
- d) selectively etching at least one cavity in the additional layer to form a second portion of the elevation element and to define patterns of a spiral-shaped balance spring having a thermo-elastic coefficient and a collet, made of silicon-based material, for the hairspring with the raised terminal curve,
- e) selectively etching at least one cavity in the bottom layer to form a third portion of the elevation element and to define a pattern of the raised terminal curve, made of silicon-based material, and
- f) releasing the one-piece hairspring with the raised terminal curve from the substrate so as to form the hairspring.
A method of manufacturing a one-piece hairspring with a raised terminal curve, the method includes the following steps:
- a) providing a substrate including a top layer and a bottom layer of silicon-based materials,
- b) selectively etching at least one cavity in the top layer to define a first portion of an elevation element, made of silicon-based material, for the hairspring with the raised terminal curve,
- c) joining an additional layer of silicon-based material to the etched top layer of the substrate,
- d) selectively etching at least one cavity in the additional layer to form a second portion of the elevation element and to define a pattern of the raised terminal curve, made of silicon-based material,
- e) selectively etching at least one cavity in the bottom layer to form a third portion of said elevation element and to define patterns of a spiral-shaped balance spring and a collet, made of silicon-based material, for the hairspring with the raised terminal curve, and
- f) releasing the one-piece hairspring with the raised terminal curve from the substrate so as to form the hairspring.
Dependencies are inferred from the claim text.