Keyboard assembly
US4468542A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1983 |
| Grant date | Aug 28, 1984 |
| Priority date | — |
| Expiry date | May 16, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H13/7006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A keyboard assembly including a plurality of key operated switches, each of which includes a dome associated with contacts on a printed circuit board which when triggered upon being subjected to a triggering force closes the switch and upon being released opens the switch and a keycap or push button for operating the dome and a transmission system for transmitting a force from the keycap to the dome which includes an actuator extending from the keycap and a conically shaped helical spring between the actuator and the dome with the small end of the spring in working engagement with the dome. The underside of the dome is vented to the atmosphere through a vent in the printed circuit board which is sealed against contamination of dust by a perforated adhesive backed plastic film or sheet over the underside of the printed circuit board.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.