Abstract: Door operator for commercial and domestic use with swing-mounted doors are disclosed. Each operator employs a variable-speed d.c. motor as prime mover, and a vertically oriented door-driving operator output shaft journalled in a transmission having a compact transmission housing which includes shock mounts for mounting of the transmission housing and operator within structure associated with the door. The transmission provides speed reduction coupling of the motor drive shaft to the operator output shaft with substantially right-angled relationship between their axes of rotation. The transmission includes a drive gear, to which the motor drive shaft is coupled by miter gear arrangement of different types, with the drive gear in coaxial relation with the operator output shaft but independently rotatable about it.

Abstract: A door operator of electromechanical character for utilization with swing-mounted doors is provided in a self-contained unit for mounting as a part of a door frame or for attachment to existing doors and frames. The opener has a door driving shaft mounted for rotation about a vertical axis and connectable to a door for closing and opening of the door when rotated, and a transmission interconnecting a prime mover and door driving shaft for rotation to open the door upon selective delivery of power by the prime mover. A pinion interconnected with the shaft meshes with a rack gear for shifting of the rack gear about a longitudinal axis in response to rotation of the shaft. The unit includes a module of interchangeable character having a preloaded spring and configured for the intended direction(s) of rotation of the door for opening.

Abstract: A door operator with a reciprocable rack gear adapted to be actuated in opposite directions by an electric motor driven screw and a coaxial helical compression spring for rotating a drive gear of a door operating spindle in opposite directions for opening and closing a swinging door, the rack gear forming part of a spindle operator having lateral bearings engageable with the ends of the spindle and adapted to be mounted in either of two 180.degree. angularly spaced positions about the axis of the drive screw for rotating the spindle in opposite directions, and the coaxial compression spring being operable via the rack gear for biasing the spindle in both directions to an intermediate position thereof.

Abstract: A traffic door biased to the closed position and adapted to be swung to the open position when pushed manually or engaged by material handling equipment. The traffic door includes an inverted L-shaped frame and a spring loaded cam mechanism is associated with the upper horizontal frame section of the frame and acts to bias the door to the closed position. Both the vertical and horizontal frame sections include a hollow rail having longitudinal recesses in opposite edges. The door panels are secured within the inner recesses of the rails by wedge-shaped strips, while channel members are secured in the outer recesses and carry a pair of weather strips which engage the jamb and header of the doorway. The outer vertical edge of each door panel is clamped within an edge seal strip which includes an outer flexible hinge section and a pair of arms having teeth or serrations which are clamped to opposite faces of the respective panel.

Abstract: A door operator of electromechanical character for utilization with pivotally mounted doors, as by a center pivot, a butt hinge, or an offset pivot, comprising a prime mover, a driving shaft, adapted for rotation about a vertical axis and being secured through an arm to the door to be operated. A gear train interconnects said prime mover and said driving shaft wherein the gears are mounted as by a unique arrangement of needle roller and needle thrust bearings to permit said gear train to operate smoothly in door opening operation as a speed reducer and in door closing operation as a gear increaser. Energy storing means operatively connected to said driving shaft for storing energy during door opening operation and for energy releasing to drive said gear shaft during door closing operation. The said operator is adapted for compact disposition within the header of a door frame.

Abstract: An electromechanically operated dockboard. The dockboard includes a ramp hinged at its rear edge to a supporting frame and the ramp is adapted to be moved from a generally horizontal cross traffic position to an upwardly inclined position by operation of a recirculating ball screw unit, which is connected between the frame and the ramp and is driven by a permanent magnet motor. A lip is hinged to the front edge of the ramp and can be pivoted from a pendant, downwardly hanging position to an extended position where it forms an extension to the ramp. Deactivation of the ball screw unit, after the ramp is elevated, causes the ramp to fall by gravity, and as the ramp descends, the lip is lifted to the extended position where it will engage the bed of the truck. During the descent of the ramp the ball screw unit is driven in a reverse direction and the permanent magnet motor serves as a brake to control the speed of descent.

Abstract: An electronic door control system is disclosed having a d.c. motor rotatable in one direction for opening a door and in the opposite direction for closing the door. One or more semiconductor devices (preferably SCR's) supply d.c. power to the motor from an a.c. power source when rendered conductive. A polarity selecting circuit controls the polarity of d.c. power supplied to the motor and thus its rotational direction. A sensor (e.g. floor mat) senses body pressure near the door to enable conduction of the semiconductor device and provide a first d.c. power polarity for a predetermined period to open the door. A circuit reverses the polarity after the door is opened, thereby closing the door. A speed control circuit responsive to counterelectromotive force developed by the motor effectively controllably varies the conductivity of the semiconductor device in a sense tending normally to cause motor rotation, and thereby door movement, at a predetermined speed.

Abstract: An electromechanically operated dockboard. The dockboard includes a ramp hinged at its rear edge to a supporting frame and the ramp is adapted to be moved from a generally horizontal cross traffic position to an upwardly inclined position by operation of a recirculating ball screw unit, which is connected between the frame and the ramp and is driven by a permanent magnet motor. A lip is hinged to the front edge of the ramp and can be pivoted from a pendant, downwardly hanging position to an extended position where it forms an extension to the ramp. Deactivation of the ball screw unit, after the ramp is elevated, causes the ramp to fall by gravity, and as the ramp descends, the lip is lifted to the extended position where it will engage the bed of the truck. During the descent of the ramp the ball screw unit is driven in a reverse direction and the permanent magnet motor serves as a brake to control the speed of descent.