Improvements in pneumatic motors for actuating means for vehicle windscreen wipers

摘要

683,145. Pneumatic motors and valve gear. LUCAS. Ltd., J. Feb. 22, 1951 [Feb. 28, 1950], No. 5051/50. Classes 122(ii) and 122(iii) A pneumatic motor suitable for actuating a windscreen wiper comprises a valve plate a, a cylinder c formed on or secured at one end to one side of the valve plate. a piston f reciprocable in the cylinder and having a piston rod g extending through the valve plate, an air control valve carried by the valve plate on the opposite side of the cylinder and actuated in response to piston movements to supply air to the opposite ends of the cylinder alternately, a detachable enclosure d surrounding the cylinder and effecting communication between the valve plate and the end of the cylinder remote therefrom, and a detachable cover v enclosing the valve. A passage m in the valve plate is connected to a suction source by a pipe band is alternately placed in communication with one end of the cylinder c through a port n and a port o and a passage p whilst the other end of the cylinder is open to atmosphere, by a spring-loaded pivoted member i oscillated by a bell-crank lever j actuated alternately by a tappet r attached to the piston rod g and a second tappet u operated either by the piston f or by a tappet attached to the piston rod.