Importance

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Abstract

An improvement in door activating control apparatus including a short delay between the time the door is stopped during its closing direction of travel and starts moving in the opening direction when any one of any switch or button for opening the door is activated, prevents the stress incurred when the door is required to instantly reverse its direction of travel while closing, demonstrates a distinct advantage especially when controlling large heavy doors, or for door openings that require a high volume of traffic and in emergency situations, includes a means to by-pass the delayed reversing when the door is in the closed position. Features a novel means of using a single pole double throw switch which will serve to defeat a safety edge device and by-pass the delayed reversing, embodied in a single enclosure along with the door closing limit switch, all actuated by a single mechanical actuating device at the door closed position, demonstrates distinct advantages in door operator design. Included in the circuit is an improved means to raise the door to a partial open position from a single momentarily actuated button, does not require a partial open limit switch and the height of the partial open position can be easily changed in the field. The improved circuit also provides door opening and closing pilot relays, eliminating the need for motor reversing contactors along with mechanical interlocks and self latching contacts, exhibits significant optional advantages in the selection of motor controlling relays.

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First Claim