Keyboard switch assembly
US4527021A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1984 |
| Grant date | Jul 2, 1985 |
| Priority date | — |
| Expiry date | Feb 3, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2217/024
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A key-board switching unit for electronic instruments is constructed with a printed circuit board provided with a plural number of pairs of fixed contact points on the surface and an insulating covering sheet member mounted on or above the printed circuit board and provided on the bottom surface with movable contact points to face the fixed contact points. Different from conventional units in which exact correspondence in the positions of the fixed and movable contact points is required with time- and labor-consuming assembling works, the movable contact points in multiple numbers distributed over the whole bottom surface of the covering sheet member in such a manner that, when the covering sheet member is pushed and depressed at the switching position, the fixed contact points forming a pair of the counter-electrodes are contacted and electrically connected with at least one movable contact point even without exact positioning of the covering sheet member and the printed circuit board to give a great advantage of the increased productivity in the works of assembling. In particular, the movable contact points are formed of a pressure-sensitive electroconductive rubber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.