Monobloc elevated curve spiral and method for manufacturing same

摘要

The hairspring (21) has a silicon dioxide part, and a spiral spring (25) coaxially mounted on a ferrule (27) formed in a layer made of silicon. A lifting device (2) lifts an external turn of the spring above the layer to improve the concentricity of development of the hairspring. The lifting device comprises a terminal curve (23) e.g. Phillips(RTM: screwdriver) type curve, connected to a lifting unit (4). A metal cylinder receives an axle by pressing. An independent claim is also included for a method for fabricating a monoblock hairspring.