Wristwatch case
US4473306A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 31, 1983 |
| Grant date | Sep 25, 1984 |
| Priority date | — |
| Expiry date | May 31, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04B47/042
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A crystal (1) of a wristwatch case contains a sapphire base plate (2) which, in front view, entirely covers the body (3) of the case. That plate (2) is in turn entirely covered by a second sapphire plate (4) which is glued (5) to plate (2) very rigidly. The crystal (1) is fastened to the body (3) by screws engaged from the back side of the body (3) in sockets (7), a head (9) of which is captured between the two plates (2, 4) of the crystal (1). The position of the sockets (7) is exactly determined by a conical seat (10) of housings hollowed out in plate (2), at the bottom of which rests the conical head (9) of the sockets (7). Flats (14) are formed on the heads (9), so that the glue forms packings (15) preventing the sockets (7) from turning while screwing the crystal (1). The upper face (6) of the square (3) and the heads (9) of the sockets (7) are masked by a metal coating (12) deposited by vacuum spraying on the other side of plate (4). The crystal (1) is, furthermore, decorated with semicylindrical colored sapphire baguettes (16) glued in corresponding grooves (19) of plate (4).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.