Revolving door system

  • US 4,475,308 A
  • Filed: 03/01/1982
  • Issued: 10/09/1984
  • Est. Priority Date: 03/01/1982
  • Status: Expired due to Term
First Claim
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1. A security door system for permitting passage of persons therethrough in one authorized direction while preventing persons from trying to pass therethrough in the other unauthorized direction, comprising:

  • a rotatable center shaft defining an upright axis capable of 360 degree rotation;

    a plurality of at least 3 wings circumferentially disposed about the shaft rotatable about the axis;

    a pair of upright opposing curved panels disposed in facing spaced apart relationship to define a partially enclosed region bounding the wings and defining opposing first and second openings;

    electrically operated means for rotating the shaft in first and second rotating directions;

    means for actuating the door to turn in a first rotating direction to permit an authorized person to pass through the system;

    means for detecting the presence of a person attempting to pass through the system in the opposite unauthorized direction;

    means responsive to said detecting means for automatically stopping the rotation of the door and reversing its rotating direction before the unauthorized passage is completed to back the person out toward their point of entry; and

    means for automatically re-enabling the rotation of the door in the first rotating direction when the unauthorized person is no longer detected, said stopping, reversing and re-enabling functions being performed by said system without human intervention.

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