Use of a non-magnetic coating to cover parts in a watch movement

• US 20040042349A1
• Filed: 08/27/2003
• Published: 03/04/2004
• Est. Priority Date: 02/28/2001
• Status: Abandoned Application

• Current Assignee: ETA SA Manufacture Horlogã¨Re Suisse (The Swatch Group AG)
• Original Assignee: ETA SA Manufacture Horlogã¨Re Suisse (The Swatch Group AG)
• Inventors: Burdet, Denis, Leuba, Frederic
• Application Number:
  US10/649,304
• Publication Number:
  US 20040042349A1
• Time in Patent Office: Days
• US Class Current: 368/204
• CPC Class Codes: G04C 10/00 Arrangements of electric power supplies in time pieces circuits G04G19/00; mounting, assembling of components of electromechanical watches G04C3/008, of electronic watches G04G17/00
• CPC Class Codes: G04C 3/008 Mounting, assembling of components

Abstract

The present invention proposes to improve the yield of a micro-generator (1) used for operating a timepiece. This micro-generator operates on the basis of the phenomenon of electromagnetic induction; it is thus desirable to limit the presence of magnetic masses in proximity to said generator as much as possible. Research carried out has shown that the finish coating covering the movement-blank parts (11, 12) arranged in proximity to the micro-generator brakes the latter when it is made of a magnetic material, and in particular a ferromagnetic material. Thus, the exclusive selection of non-magnetic materials for manufacturing the movement-blank and its coating is proposed.

Claims

1. Timepiece movement including in particular a micro-generator (1) including magnetised masses (5), said micro-generator (1) being surrounded at least partially by non-magnetic movement-blank parts (11, 12) coated with a finish coating, characterised in that the finish coating covering said movement-blank parts (11, 12) located in proximity to said micro-generator (1) has essentially non-magnetic properties.

2. Timepiece movement according to claim 1, characterised in that said coating includes at least two metallic layers of which at least the layer which is directly in contact with said movement-blank parts (11, 12) contains nickel as a non-magnetic alloy constituent.

3. Timepiece movement according to claim 1 or 2, characterised in that said micro-generator (1) includes a rotor (2) including two flanges (3) each substantially disc-shaped and each carrying, on its face opposite the other flange, an even number of magnetised masses (5), said micro-generator further including an electronic module (6) including at least a stator coil (4) partially inserted between the two flanges (3) and in that said micro-generator is at least partially located in a volume delimited by the orthogonal projections of said non-magnetic movement-blank parts (11, 12).

4. Timepiece movement including in particular an operating unit (1) including magnetised masses (5) and allowing the presence of an external magnetic field to be detected, said operating unit (1) being surrounded at least partially by non-magnetic movement-blank parts (11, 12) coated with a finish coating, characterised in that the finish coating covering said movement-blank parts (11, 12) located in proximity to said operating unit (1) has essentially non-magnetic properties.

5. Timepiece movement according to claim 4, characterised in that said operating unit has the function of a compass.