Fail-safe relay system
US4280164A · kind A · utility
15Cited by
9References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1979 |
| Grant date | Jul 21, 1981 |
| Priority date | — |
| Expiry date | Jul 24, 1999 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16P3/144
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A fail-safe relay system for use in infrared security barriers or other apparatus producing a sensing signal so as to control the de-activation and permit the re-activation of an interconnected device; such as a machine press. The relay system uses two relays with contacts in series in conjunction with electronic circuitry. Safe-start operation for preventing reactivation of the interconnected device if any unsafe condition exists, including failure of either pair of relay contacts to open when an unsafe condition is sensed, is also accomplished.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.