Deployment mechanism for tarping system

A cover system for an open-topped container, said system comprising:

• a flexible cover wound about a spool at one end of the container, said cover sized to span at least a portion of the open-topped container when unwound from said spool;
• a bail member attached at one end to said flexible cover and pivotably mountable at an opposite end to the container, said bail member sized to unwind the cover from said spool as said bail member is rotated, wherein said bail member includes a pair of arms disposed at opposite sides of the container;
• a hydraulic rotary actuator mounted to the container between the opposite sides of the container and including:
• at least one rotatable shaft engaged to said bail member arms;
• a body defining a chamber having first and second fluid inlets;
• and
• a linearly movable piston disposed within said chamber between said first and second fluid inlets and operably coupled to said at least one rotatable shaft, whereby pressurized fluid provided at said first fluid inlet moves said piston away from said first inlet to thereby rotate said at least one rotatable shaft in one direction, and pressurized fluid provided at said second fluid inlet moves said piston away from said second inlet to thereby rotate said at least one rotatable shaft in an opposite direction;
• and
• a control valve system connected between said first and second fluid inlets and a source of pressurized fluid, wherein said control valve system includes a first flow control valve connected to said first fluid inlet and a second flow control valve connected to said second fluid inlet, said first and second control valves selectively and independently operable to differently control the flow rate of fluid through said corresponding first and second inlets.