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
Apparatus for electrographic printing or copying
Hydrofluorocarbon refrigerant compositions for heat pump water heaters
Process for preparing synthetic intermediates of peripherally-selective inhibitors of dopamine-.beta.-hydroxylase involving catalytic asymmetric hydrogenation
Semiconductor devices and methods for changing operating characteristics and semiconductor systems including the same
Circuit board and display panel assembly having the same
Semiconductor device and manufacturing method thereof
Bluetooth headset
  Randomly Featured Patents
PTC electrical devices for installation on printed circuit boards
Signal encoding apparatus, audio data transmitting method, audio data recording method, audio data decoding method and audio disc
Die-less drawing method and apparatus
Method and apparatus for monitoring multi-wavelength optical systems
Photomask material
System for preventing multiple instances of the same dynamic executable module
Ophthalmologic information processing apparatus and ophthalmologic examination apparatus
System and method for parsing, filtering, and computing the checksum in a host Ethernet adapter (HEA)
Applicator tool
Combined gas heater and table