	US 11,898,225 B2
	Spiral spring for a horological movement
Christian Charbon, Chézard-St-Martin (CH); Lionel Michelet, Fleurier (CH); and Marco Verardo, Les Bois (CH)
Assigned to Nivarox-FAR S.A., Le Locle (CH)
Filed by Nivarox-FAR S.A., Le Locle (CH)
Filed on Mar. 15, 2022, as Appl. No. 17/654,870.
Claims priority of application No. 21162933 (EP), filed on Mar. 16, 2021.
Prior Publication US 2022/0298610 A1, Sep. 22, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C22C 27/02 (2006.01); G04B 17/06 (2006.01)

CPC C22C 27/02 (2013.01) [G04B 17/066 (2013.01)]

17 Claims

1. A spiral spring configured to equip a balance of a horological movement, wherein the spiral spring is made of an alloy consisting of:

Nb in a range of from 40 to 84 wt. %;

Ti in at least 15 wt. %; and

Zr and/or Hf;

optionally, W;

optionally, Mo; and

optionally, O, H, Ta, C, Fe, N, Ni, Si, Cu, and/or Al,

wherein a total content of the Ti, Zr, and Hf is in a range of from 16 to 55 wt. %,

wherein a W content is in a range of from 0 to 2.5 wt. %,

wherein a Mo content is in a range of from 0 to 2.5 wt %,

wherein a content for each of the O, H, Ta, C. Fe, N, Ni, Si, Cu, and Al is in a range of from 0 to 1600 ppm,

wherein sum of the O, H, Ta, C, Fe, N, Ni, Si, Cu, and Al is less than or equal to 0.3 wt. %, and

wherein the spiral spring has a modulus of elasticity of at least 110 GPa.