Automatic transmission for automobiles

摘要

Automatic transmission for automobiles including a hydraulic torque converter and a transmission gear mechanism which has a plurality of friction devices such as clutch and brakes whereby a plurality of different driving stages can be provided through selective actuation of the friction devices. Trimmer valve is provided for each actuator of the friction device to provide a supply of gradually increasing hydraulic pressure. The trimmer valve is applied at its return port with a pressure corresponding to the engine throttle valve position so that the initial pressure to be applied to the actuator is determined in accordance with the engine throttle valve position.