Hydraulic control system for automatic gearbox of vehicle

摘要

A hydraulic control system for the automatic gearbox of a motor vehicle, has a control valve (e) to prevent an attempted engagement of reverse gear at a time when the vehicle is moving forwards. The valve (e) can take up either of two positions, the first of which results in the coupling of connections (a, d) or alternatively a second position which couples connections (b, d) dependent upon pressure being exerted on the valve stem or not by an electromagnetic armature and coil (f). Forward motion of the vehicle causes the valve (e) to adopt the first positon (a, d) when oil pressure is withdrawn from the friction-operated element (c).