Universal door safety system

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 to provide opening and closing movement to the door relative to a door frame opening, comprising, in combination;

• a transmitter and a receiver of a beam of energy;
• means mounting said transmitter and receiver to project an energy beam transversely of the door movement to be responsive to an interruption of the beam by an obstruction to door closing movement;
• a safety control circuit;
• an output from said safety control circuit for connection to the main control circuit of the existing garage door opener;
• controllable switch means connected to said safety control circuit to initiate at least two of four modes of operation of door opening, door stopped open, door closing, and door stopped closed;
• door movement responsive means responsive to actual movement of the door and connected to said safety control circuit;
• and
• determining means in said safety control circuit connected to said responsive means and to said energy beam receiver to determine if the door is closing and to determine the presence of an obstruction to door closing movement to apply a signal to the main control circuit to stop the door in its closing movement.

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 to provide opening and closing movement to the door relative to a door frame opening, comprising, in combination:

• monitor means responsive to an obstruction to door closing movement;
• a safety control circuit responsive to said monitor means to be responsive to an obstruction to door closing movement;
• controllable switch means normally connected to the main control circuit to initiate at least two of four modes of operation of door opening, door stopped open, door closing, and door stopped closed;
• means to disconnect said controllable switch means from said main control circuit;
• and
• means connecting said safety control circuit between said controllable switch means and the main control circuit, whereby said safety control circuit is adapted to stop the door in its closing movement upon said monitor means determining the presence of an obstruction to door closing movement.