Safety switch system with photooptical and capacitance detection
US5410148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1993 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | May 14, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/960705
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A switch system for an industrial machine is described which combines both optical and capacitance switches in a switch assembly. A photo-optical switch is positioned in each assembly to provide an output signal upon the introduction of a human hand into an opening formed therein, and a capacitance sensitive touch plate switch is positioned within the opening to provide an output signal upon contact by a human hand. Circuitry responds to the substantially simultaneous activation of both the optical and capacitance switches within the switch assembly and produces an output signal. Typically two of such switch assemblies are used to control power to an industrial machine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.