Spiral spring made of athermal glass for clockwork movement and method for making same
US7753581B2 · kind B2 · utility
8Cited by
4References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2006 |
| Grant date | Jul 13, 2010 |
| Priority date | — |
| Expiry date | Jun 22, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04D3/0089
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The balance spring is made from a photostructurable glass plate by UV irradiation, thermal treatment and etching, said glass having a Young's modulus thermal coefficient CTE0. The value CTE0 of selected zones of the balance spring are altered to a value CTEi by UV irradiation through one or several masks, possibly completed by a thermal treatment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.