Abstract: A safety reverse arrangement is disclosed for reversing the direction of the powered operation of a door upon encountering an obstacle during its opening and closing movement. The arrangement includes a piston fit within a vented cylinder, which is stroked by the opening and closing movement of the door, while a pair of air flow detector switches receive the resulting air outflow developed during stroking of the piston. The air flow detector switches are integrated with a control circuit for the door powering arrangement such that, after an initial short delay period, any interruption in the flow to the flow detector results in a reversing of the direction of the door movement. Such interruption of air flow occurs upon the door encountering an obstacle during its opening or closing movement.

Abstract: A telephone hook-up box for providing dockside telephone line hook-up to a mating connector plug. The hook-up box incorporates all of the connections necessary for hooking up the telephone lines and the respective line protectors and line continuity checking resistor. The box is formed of a two-piece body and cover portion of molded plastic. The cover is adapted to receive a locking type connector plug with a corresponding mating spring finger contact set disposed in a bore formed in the body element aligned with the cover openings. The spring contacts are integral with three molded-in-place contact-terminal elements which provide the terminal tab portions for both the telephone line and ground hook-ups and connection of the lines to a continuity checking resistor mounted in the body element. The ground contact-terminal elements are also formed with contact seat portions providing a grounding connection to the respective line terminal tab portions.