A control system for a continuously variable transmission for a motor vehicle has a transmission ratio control valve having a spool for controlling oil supplied to a cylinder of a drive pulley to change the transmission ratio. The transmission ratio control valve has chambers at both ends of the spool....http://www.google.es/patents/US4833944?utm_source=gb-gplus-sharePatente US4833944 - Transmission ratio control system for a continuously variable transmission
Transmission ratio control system for a continuously variable transmission
