US 12,481,248 B2
Method for manufacturing horological balance springs
Geoffrey Chassin, Morteau (FR); and Pierre Cusin, Villars-Burquin (CH)
Assigned to NIVAROX-FAR S.A., Le Locle (CH)
Filed by NIVAROX-FAR S.A., Le Locle (CH)
Filed on Nov. 8, 2024, as Appl. No. 18/941,193.
Claims priority of application No. 23217974 (EP), filed on Dec. 19, 2023.
Prior Publication US 2025/0199476 A1, Jun. 19, 2025
Int. Cl. G04B 17/06 (2006.01); G04D 7/10 (2006.01)
CPC G04B 17/066 (2013.01) [G04D 7/10 (2013.01); Y10T 29/49579 (2015.01); Y10T 29/49609 (2015.01)] 12 Claims
OG exemplary drawing
 
1. A method for manufacturing a batch of horological balance springs (2a), comprising an average stiffness within a predetermined range, which method comprises the following steps of:
a) forming, in a wafer (1), horological balance springs (2b, 2c), of the batch of horological balance springs (2a), with dimensions that differ from dimensions required to obtain the batch of horological balance springs (2a) comprising the average stiffness within said predetermined range;
b) forming, in the wafer (1), systems (3) for indicating a reference stiffness for determining stiffnesses of the batch of horological balance springs (2a);
c) determining the stiffnesses of said systems (3) formed;
d) computing a dimensional correction to be applied to the horological balance springs (2b, 2c) formed, on the basis of the determined stiffnesses of said systems (3); and
e) modifying the dimensions of the horological balance springs (2b, 2c) formed, on the basis of a dimensional correction computed to obtain the batch of horological balance springs (2a), the average of whose stiffnesses lies within said predetermined range,
wherein the systems (3) comprise a first system (3) and a second system (3),
wherein the horological balance springs (2b, 2c) comprise a first horological balance spring (2b, 2c) and a second horological balance spring (2b, 2c), and
wherein forming, in the wafer (1), the systems (3) comprises:
arranging the first system (3) closer to the first horological balance spring (2b, 2c) than to any other of the horological balance springs (2b, 2c), and
arranging the second system (3) closer to the second horological balance spring (2b, 2c) than to any other of the horological balance springs (2b, 2c).