Patent ID: 8297924

Claim:
An actuation system comprising: a pump assembly including a pump chamber; an actuator having first and second chambers and a movable member and configured to convert pressures applied to said first and second chambers into a movement of said movable member; a valve section; and a controller configured to control said valve section to: (i) open a first flow path between said pump chamber and said first chamber and close a second flow path between said pump chamber with said second chamber, during a discharge period during which said pump chamber is pressurized, in a first mode; (ii) close said first flow path and open said second flow path during an intake period during which said pump chamber is depressurized, in the first mode; (iii) close said first flow path and open said second flow path during the discharge period in a second mode; and (iv) open said first flow path and close said second flow path during the intake period in the second mode, wherein said valve section has a plurality of positions set by said controller, and wherein the plurality of plurality of positions includes: (i) a first position in which said valve section opens said first flow path and closes said second flow path; (ii) a second position in which said valve section closes said first flow path and opens said second flow path; and (iii) a neutral position in which said valve section closes said first and second flow paths.