Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
Horizontal aggregations in a relational database management system
Bus controller for handling split transactions
Anti-proliferative and anti-inflammatory agent combination for treatment of vascular disorders with an implantable medical device
Switchgear and method for operating switchgear
Laser receiver for detecting a relative position
Method for forming a semiconductor device using selective epitaxy of group III-nitride
Thermally efficient busway
  Randomly Featured Patents
Method and apparatus for imaging volume data using voxel values
Process for producing HOE's for use in combination to produce a telecentric beam
Decorative item
Ultrasonic sensor having transmission device and reception device of ultrasonic wave
Amplifier circuit for electret condenser microphone
Process for the preparation of sulfated alkanol oxethylates or alkylphenol oxethylates having a lowered content of 1,4-dioxane
Refrigerator dismantling method, compression equipment, and refrigerator dismantling device
Rotary connector
Mattress incorporating tourmaline
Rocking member apparatus