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.

Abstract: The invention relates to a Breguet overcoil balance spring (1) that includes a hairspring (3) mounted in a single part, made of micro-machinable material, and coaxially with a collet (5). According to the invention, the balance spring has a terminal curve (7) made of micro-machinable material and an elevation device (9) made of micro-machinable material between the outer coil (15) of the hairspring and the terminal curve to improve the concentric development of the balance spring. The invention also relates to the method of manufacturing the balance spring. The invention concerns the field of timepiece making.

Abstract: The tool, which can be adapted to a bracket for fitting hands on a dial by driving them in, including a lower rod (11) which slides in a tubular part (13a) of an intermediate cylindrical element (13) compressing a spring (33) abutting against first tension adjustment means (43) and with an overlap that can be checked by a movement indicator (34) for a first force F1, said intermediate cylindrical element (13) itself sliding in the upper tube (15) compressing a second spring (35) abutting against second tension adjustment means (45) and with an overlap that can be checked by a movement indicator (36) for a second force F2.

Abstract: The tool, which can be adapted to a bracket for fitting hands on a dial by driving them in, including a lower rod (11) which slides in a tubular part (13a) of an intermediate cylindrical element (13) compressing a spring (33) abutting against first tension adjustment means (43) and with an overlap that can be checked by a movement indicator (34) for a first force F1, said intermediate cylindrical element (13) itself sliding in the upper tube (15) compressing a second spring (35) abutting against second tension adjustment means (45) and with an overlap that can be checked by a movement indicator (36) for a second force F2.