Control of continuous reciprocation of a fluid power cylinder

A system for controlling the reciprocation of and the acceleration and deceleration of the extend and retract strokes of a double-acting fluid cylinder having opposing power ends, comprising:

• means connectable with a double-acting cylinder for supplying pressurized fluid alternately to opposite cylinder ends;
• said fluid supplying means including a direction control shiftable between extend and retract conditions to, respectively, extend and retract the rod of the cylinder;
• drive means, including a rotary hydraulic fluid motor, connected with said direction control for shifting said direction control;
• control means connected with said fluid motor for operating said fluid motor including:
• means including a speed control valve for supplying pressurized fluid to said motor;
• parallel connected start and stop valves connected between said fluid motor and said supplying means for controlling the passing of passing of fluid from said supplying means to said motor;
• means responsive to the extend and retract strokes of the rod acting to open and start valve when the rod is at the limit of either its extend or retract stroke, and to close said start valve during the operation of said rod between said limits;
• and stop valve operator means coupled with said motor for opening and closing said stop valve in timed relation with movement of said direction control, said stop valve operator means acting to close said stop valve when said direction control means is shifted to an extend or retract condition, and to open said valve during the shifting of said direction control between said conditions.