Switch with conical spring actuator
US4529848A · kind A · utility
19Cited by
6References
30Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 22, 1983 |
| Grant date | Jul 16, 1985 |
| Priority date | — |
| Expiry date | Aug 22, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2235/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A capacitive or a membrane switch is provided with a coil spring which has a conical base and a top cylindrical portion. The spring biases a switch key to its rest position. When the key is pressed, the conical base is compressed to provide an exponentially increasing counter-force and to actuate the switch at a predetermined actuation point. After the switch is actuated, the key continues to move and compresses the cylindrical portion of the spring to provide a linearly increasing counter-force which indicates overtravel operation of the switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.