Fixation of double conducting hairspring
US3934403A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 17, 1975 |
| Grant date | Jan 27, 1976 |
| Priority date | — |
| Expiry date | Mar 17, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49579
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention comprises an improved hairspring arrangement having a hairspring fixed in a groove of the hub in such a way that the hairspring protrudes from the groove, and furthermore, the protruding part of the hairspring should carry the electric conductor. The basic conception of the invention makes it possible to fix the hairspring, which has the customary shape of an upright standing metal strip, to the hub in the usual way. Normally one of the front surfaces of the hub is equipped with a straight or ring-shaped notch which reaches to the peripheral area of the hub and into which the inner end of the hairspring is inserted and then is fastened in the hub by deforming the notch-rims. Up to now the chosen depth of the notch was at least equal to the height of the metal strip forming the hairspring. According to the present invention, however, the height of the upright standing and hairspring-forming metal band is chosen larger than the depth of the notch arranged on one of the front surfaces of the hub, so that one longitudinal edge of the hairspring protrudes from the hub. If the electric conductor is then arranged on this longitudinal edge of the hairspring--naturally by inte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.