When lever 1 is turned clockwise about fixed axis A, tie-rod 2 turns lever 3 about axis O. A projection of lever 3 fits with a certain lengthwise clearance in a slot of link 10. Valve spool 4 is shifted to the right. At this, a part of the fluid, admitted under pressure into the body of valve spool 4, is delivered through rotary valve 5 to the top end of power cylinder 6. Piston 7 moves downward so that elevator 8 is inclined upward. Fluid from the bottom end of cylinder 6 is drained through the valves to the tank. At the same time, a part of the fluid under pressure is admitted to the right end of spool 4. This pressure is transmitted to the control lever. As elevator 8 is raised, turning about fixed axis B, tie-rod 9 turns lever 10 about fixed axis C. At the same time, lever 3 with axis O is displaced, enabling control lever 1 to continue to turn in the same direction. If control lever 1 is turned counterclockwise, the elevator is lowered.
$3960$LHP,Co$