Multi-pole momentary membrane switch
US4987275A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1989 |
| Grant date | Jan 22, 1991 |
| Priority date | — |
| Expiry date | Jul 21, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2225/006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A membrane keyboard is comprised of a dielectric substrate and an overlying deflectable membrane layer separated by a spacer. A plurality of contact poles are located on the dielectric substrate with an electrically conductive common contact area located on the flexible membrane. A portion of the flexible membrane is locally stiffened and, in a preferred embodiment, provided with a ridge extending away from a portion of the membrane towards the contact poles. Upon actuation of the switch, the stiffened portion of the membrane ensures simultaneity of contact between the common contact area on the membrane and the contact poles on the substrate. Preferred embodiments utilize a generally circular ridge in the deflectable membrane cooperating with interdigitated contact poles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.