Eta Sa Fabriques D'ebauches

Eta A.g. Ebauches-fabrik

Eta Sa Manufacture Horlogere Suisse

Eric Favre

Friedrich Perrot

Philippe Marmy

Pierre-Alain Vuille

Christoph Schlencker

Christoph Schlenker

A method for manufacturing a balance-spring for a clockwork movement wherein a spring is formed by winding, from a wire or metal strip, said spring including an inner end intended to be fixed to a balance and a outer end zone intended to be fixed to the balance-spring stud and wherein the whole spring is subjected to a first heat treatment subsequent to the winding step of said wire. The method of the invention is characterized in that it further includes an additional step consisting in subjecting at least said outer end zone to a second heat treatment. This method improves in particular the shock resistance of the balance-spring.

Method for manufacturing a balance-spring obtained according to said

A hairspring and collet assembly for timepieces in which the collet has a base having an opening and a stud integral from the base in a direction parallel to the axis of the opening. The hairspring comprises an inner turn ending in a bend. The stud occupies a portion of the base extending between the opening and the periphery of the base. The non-deformed portion of the inner turn of the hairspring is secured to the stud and the bend extends freely away from the stud about the opening.

Hairspring and collet assembly for timepieces

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Grenchen, Switzerland

Eric Favre