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US 11,982,977 B2Granted
Method of manufacturing a timepiece shaft
AssigneeRolex SA
InventorVannina Linck
Life of this patent
Estimating the term…
Abstract
The method of manufacturing a timepiece shaft (1) includes grinding a ceramic piece, especially to form a balance shaft (1), having a functional portion (2a; 2b) including at least one part (221a; 221b) of a pivot-shank (22a; 22b) and/or at least one part (211a; 211b) of a pivot (21a; 21b), the first functional portion being made of ceramic and a first outer diameter (D1) of the first functional portion being less than 0.5 mm, or less than 0.4 mm, or less than 0.2 mm, or less than 0.1 mm.
Claims20
A method of manufacturing a timepiece shaft, comprising:
- forming a ceramic piece entirely made in a homogeneous ceramic by extruding a ceramic thread, by injection molding a ceramic, or by pressing a ceramic preform,
- the ceramic having a hardness in a range of 1100-1600 HV1, and
- grinding the ceramic piece to form a first functional portion having a surface of revolution including at least one part of a pivot-shank and at least one part of a pivot,
- the first functional portion formed by the grinding having at least one dimension of greater than 20 μm, and a maximum diameter forming an outer diameter of the shaft of less than 0.5 mm,
- wherein the ceramic piece has a second functional portion,
- wherein the ceramic piece having the first and second functional portions forms the timepiece shaft without subjecting the first functional portion to a heat treatment nor rolling.
3 more elements
Dependencies are inferred from the claim text.