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
Cognitive radio cooperative spectrum sensing method and fusion center performing cognitive radio cooperative spectrum sensing
High purity diphenyl sulfone, preparation and use thereof for the preparation of a poly(aryletherketone)
Sensing during magnetic resonance imaging
Negative electrode material for non-aqueous electrolyte secondary battery, method for manufacturing negative electrode material for non-aqueous electrolyte secondary battery, non-aqueous elect
Digital display
Low drop-out regulator providing constant current and maximum voltage limit
Application authentication system and method
  Randomly Featured Patents
Method and arrangement for actuating an automatic transmission of a motor vehicle
Data-aware SRAM systems and methods forming same
Method and apparatus for armament control
Continuous web winding method and device with suction-induced winding start of empty core mandrels
Transmitting/receiving device and transmitting/receiving method
Systems and methods for detecting line flapping in optical networks
Manufacturing method of a semiconductor device having wirings
Backbone modified oligonucleotide analogs
Electrochemical power cells and method of improving electrochemical power cell performance
Injection device with tensioning spring and tensioning element