Hairspring for a timepiece movement

Abstract

The hairspring (1; 1′) has a spring blade (11; 11′) and a connecting member (12; 12′) for fastening the hairspring (1; 1′) to a frame (5, 6, 8), the connecting member including first (13a; 13a′) and second (13b; 13b′) fastening element, a first arm (121; 121′) connecting the first fastening element (13a; 13a′) to the second fastening element (13b; 13b′), and a second arm (122; 122′) connecting the first arm (121; 121′) to the spring blade (11; 11′), the second arm (122; 122′) being connected to the spring blade (11; 11′) in a first joining zone (122a; 122a′), the hairspring (1; 1′) being configured or arranged so that a first displacement of a first amplitude of the first fastening element (13a; 13a′) relative to the second fastening element (13b; 13b′) does not cause any displacement of the second arm (122; 122′), particularly of the first joining zone (122a; 122a′), or causes a second displacement of a second amplitude of the second arm (122; 122′), particularly of the first joining zone (122a; 122a′), relative to the second fastening element (13b; 13b′), the second amplitude being less than 0.15 times or 0.1 times or 0.05 times the first amplitude.

Dependencies are inferred from the claim text.