Optical safety shutoff for machine cover
US5216246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1992 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Feb 3, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/94068
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An interlock system for a machine cover including an optical sensor providing a cover open signal, a housing secured to the cover and defining a hollow cavity communicating with the optical path with the cover closed, a reflector fixed to one end of the cavity to reflect light to the sensor with the cover closed, a wall forming part of the housing and disposed in an interference relationship with the optical path for blocking light with the cover open, the length of the optical path with the cover open being less than the length of the optical path with the cover closed, and circuitry to trigger the optical sensor to provide light pulses at a predetermined frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.