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Automatic door safety system

  • US 4,914,859 A
  • Filed: 09/23/1988
  • Issued: 04/10/1990
  • Est. Priority Date: 04/16/1987
  • Status: Expired due to Fees
First Claim
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1. An automatic door structure having doorway comprising a door mounted for movement in said doorway, a plurality of stationary and moving object presence sensing detectors arranged to produce stationary and moving object presence sensing beams in overlapping relation to one another such that the beams, in alignment, fully span the doorway along the path of movement of the door and extend at least a predetermined distance on each side of the doorway, power means for actuating the door, and means arranged on the door operative upon movement of the door to open position to successively switch on each detector as it passes along its path to open position and effective upon reverse movement of the door to closed position to successively shut off each detector.

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