Resources Contact Us Home
Continuously monitored supplemental obstruction detector for garage door operator

Image Number 4 for United States Patent #5191268.

An automatic door operator with a continuously monitored supplemental obstruction detector. In a first embodiment, the obstruction detector is a radiant beam obstruction detector that transmits a beam of modulated radiant energy across the door opening. A safety signal generator produces an active safety signal only on unobstructed receipt of radiant energy by a receiver. Failure to receive the active safety signal when the motor is closing the door at least stops the door. A two wire cable, which carries both power and the active safety signal, connects the supplemental obstruction detector to the automatic door operator. Constant activation of a portable transmitter or of a local push button can override the supplemental obstruction detector to close the door. An alternative supplemental obstruction detector includes a safety edge having a compressible tube disposed on a leading end of the door. Plural conductors change their conductive state upon compression of the compressible tube. This embodiment may include a delay upon detection of compression of the compressible tube so that contact with the floor is not detected as an obstruction.

  Recently Added Patents
Tubular folding chair bag
Front bumper
Replaceable non-volatile memory apparatus with a plurality of pluggable electrical connectors
Coffee capsule
Single-phase and three-phase dual buck-boost/buck power factor correction circuits and controlling method thereof
Tool for predicting capacity demands on an electronic system
Nail dryer
  Randomly Featured Patents
Substrate selection for a catalyst
Integrated condenser/separator for fuel cell exhaust gases
Determining a subscriber device has failed gracelessly without issuing a DHCP release message and automatically releasing resources reserved for the subscriber device within a broadband networ
Direct digitally tunable microwave oscillators and filters
Thickeners having two ionic components and use thereof in aqueous compositions
Thermo-electric power generation using porous metal blocks having a plurality of thermocouples connected in series
Liquid logic structures for electronic device applications
Blank for a pair of nested containers
Method and apparatus for stimulating the healing of medical implants