Garage door opener
US6181095A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1999 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Sep 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2009/00928
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A power actuated door opener is disclosed with a beam break system for detecting obstructions in a door opening. A transmitter includes a beam emitter and emitter drive circuit for transmitting a train of emitter pulses to a receiver. The receiver includes a pulse detector circuit with a beam detector for producing detector pulses in response to emitter pulses impinging on the detector. The emitter drive circuit and the pulse detector circuit are synchronously coupled with each other and the pulse detector circuit produces a normal output signal only if the detector receives a pulse which is in synchronism with an emitter pulse. The receiver includes an annunciator which produces an audible and a visible warning signal when the pulse detector circuit produces a fault output signal. The audible annunicator is a piezoelectric crystal mounted in the receiver housing with a cover plate operating as a sounding board.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.