Two conductor hairspring-hub arrangement for electric watches
US3950938A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1975 |
| Grant date | Apr 20, 1976 |
| Priority date | — |
| Expiry date | Feb 24, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04C3/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The two conductor hairspring-hub arrangement comprises a metallic and substantially conventional hairspring which is fastened to a unitary hub, i.e. a metallic washer-like hub, to form a core or inner conductor. This inner conductor is sheathed with an insulating mantle or layer which is, in turn, coated with an electrical conductive mantle, i.e. an outer conductor insulated from the inner conductor. The insulating and conductive mantles have openings so that separate electrical connection can be made to the inner and outer conductors at each end of the hairspring-hub arrangement. In this manner, a two conductor hairspring-hub arrangement is provided which in an electric watch is capable of coupling drive pulses to a balance wheel drive coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.