Watch crystal bonded to watch case with low temperature solder material
US4433921A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1982 |
| Grant date | Feb 28, 1984 |
| Priority date | — |
| Expiry date | May 18, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04B39/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The watchcase essentially comprises a crystal 1, or other transparent part visible from the outside of the case, assembled to the body 2 or a bezel exclusively by way of a layer 3 of low-temperature solder, in the nature of a silver or tin solder. A layer of barrier coating 5, chromium for example, serves to avoid diffusion of solder in the liquid state to the surface of the crystal. The zone of junction may be masked by a metallic coating 4, and the grip of the solder may be improved with a supplementary junction layer 6. It is thus possible to make watchcases of distinguished appearance, comprising junction areas of narrower width than those required when cement is used for the assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.