Patent ID: 8840522

Claim:
An apparatus for controlling a variator having at least one roller between a first toroidal disk coupled to an input of an automatic transmission and a second toroidal disk coupled to an output of the transmission, the apparatus comprising: at least one actuator responsive to fluid pressure at separate high side and low side fluid inlets thereof to control torque applied by the at least one roller to the first and second toroidal disks, and first and second variator switching valves each receiving a first fluid at a first pressure and a second fluid at a second pressure less than the first pressure, the first and second variator switching valves together defining four different operational states and supplying the first fluid to the high side fluid inlet of the at least one actuator and the second fluid to the low side fluid inlet of the at least one actuator during each of two of the four different operational states and supplying the second fluid to the high side fluid inlet of the at least one actuator and the first fluid to the low side fluid inlet of the at least one actuator during each of the remaining two of the four different operational states.