Agricultural implement with hitch control

Claim 1

A ground-working implement having a fore-and-aft frame including front and rear ends, wheel means disposed below the frame rearwardly of the front end, cranked axle means journaling the wheel means and including an arm rockable on the frame, power means connected between the frame and cranked axle means arm for raising and lowering the frame between raised and lowered modes, a hitch member connected to the front end of the frame on a transverse axis and extending forwardly for connection to and support on a draft vehicle for vertical movement relative to the vehicle, and linkage means operatively connected between the hitch member and the cranked axle means for controlling relative movement between the frame and hitch member about the aforesaid axis, characterized in that the linkage includes a lever arm having upper and lower terminal ends and pivoted on a transverse axis at its lower terminal end to the front end of the frame, stop means cooperative between the frame and lever to limit forward movement of the lever in the raised mode of the frame, a compression link connected between the upper end of the lever arm and the arm of the cranked axle means and a second compression link connected between the hitch member and a portion of the lever arm above its pivot to the frame, the connection of the first link to the arm of the cranked axle means being so constructed as to enable only relative pivoting between said link and arm about a transverse axis, the connection of the first link to the lever arm including a one-way lost-motion device having an abutment effective to engage the lever arm only during the raised mode of the frame so as to lock out relative movement between the frame and cranked axle means and also between the frame and hitch member about the aforesaid transverse axes.