US 11,703,804 B2
Method for manufacturing timepiece thermocompensated hairsprings of precise stiffness
Frédéric Maier, Neuchâtel (CH); and Sylvain Jeanneret, Colombier (CH)
Assigned to PATEK PHILIPPE SA GENEVE, Geneva (CH)
Appl. No. 16/980,124
Filed by PATEK PHILIPPE SA GENEVE, Geneva (CH)
PCT Filed Mar. 15, 2019, PCT No. PCT/IB2019/052107
§ 371(c)(1), (2) Date Sep. 11, 2020,
PCT Pub. No. WO2019/180558, PCT Pub. Date Sep. 26, 2019.
Claims priority of application No. 18162723 (EP), filed on Mar. 20, 2018.
Prior Publication US 2021/0003971 A1, Jan. 7, 2021
Int. Cl. G04B 17/06 (2006.01); G04D 3/00 (2006.01)
CPC G04B 17/066 (2013.01) [G04D 3/0041 (2013.01); G04D 3/0069 (2013.01)] 12 Claims
OG exemplary drawing
 
1. Method for manufacturing timepiece hairsprings comprising the following successive steps:
a) forming hairsprings in a wafer,
b) forming a thermal compensation layer on the hairsprings,
c) identifying the hairsprings having a stiffness within a predetermined range,
d) optionally, detaching the hairsprings identified in step c) from the wafer,
e) modifying the other hairsprings so that the stiffness of at least some of them is within the predetermined range,
f) detaching from the wafer these other hairsprings and, if they have not been detached in step d), the hairsprings identified in step c).