초록 ▼

An agricultural implement, having ground engaging tools mounted on subframes that are movable through hydraulic actuators between raised transport and lowered working positions, is provided with a hydraulic circuit in which the actuators are connected in parallel with one another within a grouping o

An agricultural implement, having ground engaging tools mounted on subframes that are movable through hydraulic actuators between raised transport and lowered working positions, is provided with a hydraulic circuit in which the actuators are connected in parallel with one another within a grouping of the actuators. The positioning of the ground engaging tools into a lowered working position closes the hydraulic circuit for the group of actuators. The subframes are arranged to float over ground undulations to maintain a common working depth for the ground engaging tools. The vertical movement of any one of the actuators in the common group will force a displacement of a corresponding amount of hydraulic fluid, which will then be shared by all of the remaining actuators in the corresponding group. A depth averaging control for the ground engaging tools and a mechanical headland stop apparatus are also provided for the agricultural implement.

대표청구항 ▼

[ Having thus described the invention, what is claimed is:] [1.]1. In an agricultural implement having 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, said drawbar having a pair of wing

[ Having thus described the invention, what is claimed is:] [1.]1. In an agricultural implement having 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, said drawbar having a pair of wings movable relative to one another; a plurality of subframes movably attached to said drawbar, said subframes being arranged in groups corresponding to said wings, each respective said subframe carrying ground engaging tools; a hydraulic actuator interconnecting said drawbar and each of said subframes to effect movement of each respective said subframe relative to said drawbar, the improvement comprising:a hydraulic circuit including a pump, a reservoir, and hydraulic lines interconnecting said hydraulic actuators in parallel, said actuators being operable to raise said subframes from a working position to a transport position, said hydraulic circuit further including a depth stop valve for each respective group of actuators, said depth stop valves being operable when said subframes of the corresponding group reach said working position to close said hydraulic circuit for the subframes of the corresponding group such that said hydraulic actuators of the corresponding group remain in communication with each other without hydraulic fluid entering or leaving said corresponding group of actuators;wherein the movement of said drawbar relative to said hitch actuates said depth stop valves when said subframes reach said working position.