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Universal door safety system

  • US 4,922,168 A
  • Filed: 05/01/1989
  • Issued: 05/01/1990
  • Est. Priority Date: 05/01/1989
  • Status: Expired due to Term
First Claim
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1. A safety system for universal attachment to existing garage door openers having a door operator with a main control circuit, an electric motor and a reversible drive train connected from the motor to the door, the main control circuit providing any one of four modes of operation of door opening, door stopped open, door closing, and door stopped closed, comprising, in combination:

  • a safety control circuit;

    monitor means responsive to an obstruction to door closing movement and connected to said safety control circuit;

    an output from said safety control circuit for connection to the main control circuit of the existing garage door opener;

    door movement responsive means including a flexible member connectable for movement with actual movement of the door and connected to said safety control circuit; and

    determining means in said safety control circuit connected to be responsive to actual movement of said flexible member to determine if the door is closing and connected to said monitor means to be responsive to an obstruction to door closing movement to apply a signal to the main control circuit to at least stop the door in its closing movement.

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