JAMES D RHOADS
Engineers in Reading, PA

6002217, Dec 14, 1999

Aug 19, 1997

8/914450

James C. Stevens - Mooresville IN
Robert Utterback - Indianapolis IN
James D. Rhoads - Reading PA

Dorma Door Controls, Inc. - Reamstown PA

H02K 710

318 9

The present invention relates to a door operating system for controlling the movement of a door, the system having a motor with a motor shaft for providing rotational energy to the system and a gear chain assembly for receiving the rotational energy from the motor shaft and applying the received rotational energy to the door to move the door, comprising a sprocket rotatably mounted on the gear chain assembly for rotation around an axis of the gear chain assembly and fixedly coupled to the motor shaft for receiving and transmitting the rotational energy from the motor shaft; a drive pin fixedly disposed on the sprocket for rotational movement around the axis of the gear chain assembly as the sprocket rotates around the axis; a rotational energy receiving extension rotatably mounted on the gear chain assembly and drivingly coupled to the door for moving the door; a drive dog fixedly disposed on the energy receiving extension for rotational movement around the axis of the gear chain assembly as the energy receiving extension rotates around the axis; and the sprocket and the extension being disposed on the gear chain assembly such that rotational movement of the sprocket causes the drive pin to rotatably move into contact with the drive dog and apply rotational energy to the drive dog thereby transmitting rotational energy to the door when rotating in one direction and moving away from the drive dog when rotating in the other direction.

4375735, Mar 8, 1983

Apr 15, 1981

6/254425

James D. Rhoads - Reading PA

Dorma Door Controls Inc. - Reamstown PA

E06B 700

49 68

An air lock has a chamber and a pair of doors in respective walls of the chamber. Operators associated with the doors include closers normally biasing the doors to closed positions and fluid powered openers associated with the closers capable of overriding the bias of the closers. A control system, operation of which may be initiated by initial opening displacement of one of the doors or (in one embodiment of the invention) by manually operable remote switch means, provides for opening of one of the doors and latching of the other to prevent simultaneous opening of both doors. The latch means for the doors may be overriden by direct displacement of the doors for safety purposes. The control system also triggers air handling apparatus associated with the chamber.