Keyswitch
US4255635A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1979 |
| Grant date | Mar 10, 1981 |
| Priority date | — |
| Expiry date | Sep 17, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H13/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A keyswitch includes a tubular plunger with a rectangular body slidably mounted in a rectangular housing that has a bottom wall provided in its top with a circular recess receiving the lower end of a coil spring extending up around a pair of upright spring contact strips, the lower ends of which are press fitted in the bottom wall. The inside of the plunger is provided with a cross member that normally separates the upper ends of the contact strips, but permits them to engage each other when a keycap on the upper end of the plunger is pushed down to lower the plunger. The plunger body has legs extending downwardly from its lower corners which engage the area of the housing between the plunger body and bottom wall of the housing while the plunger is in its upper position. The corners of the bottom walls are provided with downwardly extending sockets for receiving the plunger legs when the keycap is depressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.