Hydraulic controls for agricultural implements

An agricultural implement for working the ground comprising:

• a hitch adapted for connection to a prime mover;
• a drawbar movably attached to said hitch for movement between a working position and a raised transport position;
• a plurality of subframes movably attached to said drawbar, said subframes carrying ground engaging tools movable between a working position and a raised transport position relative to said drawbar, each said subframe having a hydraulic actuator connected to said drawbar to effect movement of each respective said subframes relative to said drawbar, said actuators being arranged in at least two groups;
• a hydraulic circuit including a reservoir, a pump to provide a flow of hydraulic fluid under pressure to said hydraulic actuators, and hydraulic lines interconnecting said hydraulic actuators to said reservoir and said pump;
• and
• a depth control valve associated with each said group of actuators, each said depth control valve being operable to close said hydraulic circuit for the corresponding said group of hydraulic actuators, the hydraulic actuators in each group being connected in parallel in a circuit such that said hydraulic actuators remain in communication with each other when said circuit is closed;
• wherein at least two of said subframes in each respective said group are connected to an averaging link which is operably associated with the corresponding said depth stop valve for actuation thereof according to an average depth of said connected subframes;
• and
• wherein a central portion of said averaging link abuts a depth control crank which is connected to an adjustable stop member to engage said depth stop valve when the average position of said connected subframes reaches said predetermined working position.

An agricultural implement for working the ground comprising:

• a hitch adapted for connection to a prime mover;
• a drawbar movably attached to said hitch for movement between a working position and a raised transport position;
• a plurality of subframes movable attached to said drawbar, said subframes carrying ground engaging tools movable between a working position and a raised transport position relative to said drawbar, each said subframe having a hydraulic actuator connected to said drawbar to effect movement of each respective said subframes relative to said drawbar, said actuators being arranged in one or more groups;
• a hydraulic circuit including a reservoir, a pump to provide a flow of hydraulic fluid under pressure to said hydraulic actuators, and hydraulic lines interconnecting said hydraulic actuators to said reservoir and said pump, said hydraulic circuit further including a depth control valve associated with each said group of actuators, each said depth control valve being operable to close said hydraulic circuit for the corresponding said group of hydraulic actuators;
• and
• an averaging linkage interconnecting at least two of said subframes in each respective group to define an average depth with respect to said interconnected subframes, said averaging linkage being cooperable with the corresponding said depth stop valve for actuation thereof when said average depth corresponds to said working position for said subframes.