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
Autonomous adaptation of transmit power
Phospholipid-based powders for drug delivery
Image output method and device, and image display
Sweetener compositions having enhanced sweetness and improved temporal and/or flavor profiles
Method for decoding a spatially multiplexed data signal using a maximum likelihood detection
Cryptography on a simplified elliptical curve
Method and system for coordinating client and host security modules
  Randomly Featured Patents
Monoclonal antibody specific for the adhesion function domain of a phagocyte cell surface protein
Crosslinkable compositions based on organosilicon compounds
Method and apparatus of measuring ultrasonic time travel information obtained from logging operations in a well borehole
Message screening system
Decorative lighting display with changeable shades and bulbs
Patient support systems for use with radiation therapy systems and other applications
Redundancy circuit and redundancy method for semiconductor memory device
Tape printer and tape creating method
Fan
Comparison of chemical-mechanical polishing processes