Automatic door opener and closer

An electric door operator operably connected with a door mounted for horizontal swinging movement of the door in a door opening below a transom bar, comprising:

• motor means above said transom bar including a reversible drive motor having the axis of its pulley equipped drive shaft vertically disposed;
• linkage means including a door moving shaft extending vertically through the transom bar and connected with the door;
• drive train means including a series of horizontal angularly rotating motor speed reducing torque increasing pulleys and cog belts connecting said drive motor with said door moving shaft;
• circuit means including a normally open pedestrian closed circuit activating switch and a series of current switching relays selectively applying current to said drive motor in a door opening or closing direction in accordance with the open or closed position of the circuit activating switch;
• a source of electrical energy connected with said circuit means;
• transformer means providing a direct current potential,
• one said relay having contacts interposed in wires connecting the positive potential with the respective terminal of said drive motor for door opening or closing movement in accordance with the energized or de-energized coil of said one relay;
• door opened and closed limit switches interposed in the positive potential wires;
• door opened and closed limit switch operating cams mounted on said door moving shaft;
• electrical resistance means connected with the negative terminal of said direct current potential,
• a pair of relays of said series of relays each having at least one pair of contacts interposed in the drive motor negative potential circuit and connected with said resistance means for applying a predetermined resistance value to the drive motor circuit;
• a door movement slowing switch in the coil circuit of each relay of said pair of relays for energizing the respective relay during the opening and closing movement, respectively, of said door;
• and,
• other slowing switch operating cams mounted on said door moving shaft.