Abstract: An actuating mechanism having three detented actuating positions. The actuating mechanism includes an arm having a roller rotatably mounted thereon. The roller bears against the sides of two juxtaposed coil springs which bias the arm into a neutral position when the roller is received between the springs, and an actuated position on either side of neutral when the roller rides past the centerline of one or the other of the springs. In accordance with one aspect of the invention, directional switches are actuated by the arm when the arm is moved to either side of neutral.

Abstract: An SCR which controls the speed of a battery powered vehicle is liquid cooled by a closed circuit cooling system utilizing an oscillating pump, a heat exchanging reservoir, and an SCR mounting block. The SCR mounting block forms a fluid chamber when the SCR is mounted thereto. The heat exchanging reservoir is mounted to the vehicle chassis above the oscillating pump and is connected by tubing to both the pump and to the fluid chamber of the SCR mounting block to allow the pump to recirculate the liquid through the closed cooling system. The oscillating pump is connected to the battery of the vehicle through a chopper circuit to provide pulsating liquid flow from the pump in response to the pulsating D.C. signal from the chopper circuit. The pump thus circulates the heated liquid from the fluid chamber of the semiconductor mounting block to the heat exchanging reservoir where it is cooled and circulated back to the fluid chamber.