Leveling system for a wheeled implement

A wheeled implement including a leveling system, said implement having a frame adapted to support ground-engaging tools, a hitch structure pivotally connected to said frame for movement about a transverse axis and extending forwardly to a forward end connectible to a traction vehicle, and support wheels mounted on said frame and movable between transport and working positions, said leveling system comprising:

• (a) power means for raising and lowering said support wheels, said power means including at least two wheel lift cylinders connected in parallel;
• (b) fore-and-aft leveling means for stabilizing said frame during transport and for maintaining said frame substantially parallel to the ground during both transport and working positions, said fore-and-aft leveling means including a first support arm pivotally attached at one end to a front portion of said frame, a second support arm securely attached to a point on said frame rearward of said first support arm, a hydraulic cylinder coaxially aligned with a spring assembly, said hydraulic cylinder being pivotally attached at one end to said first support arm and having a cylinder rod extending out of an opposite end which extends into said spring assembly, said spring assembly being pivotally attached to said second support arm such that said hydraulic cylinder and said spring assembly cooperate to permit flexible movement of said frame while said implement traverses over uneven terrain;
• (c) a mechanical link connected between said first support arm and said hitch structure for angularly retaining said hitch structure relative to said front portion of said frame to accommodate a drawbar hitch which can be positioned at various heights on said traction vehicles;
• (d) fluid supply means for supplying pressurized fluid to said wheel lift-cylinders and to said fore-and-aft hydraulic leveling cylinder;
• and
• (e) flow dividing means for dividing the volume of said pressurized fluid equally between said wheel lift cylinders and said fore-and-aft hydraulic leveling cylinder such that said frame can be raised and lowered with respect to the ground in a substantially horizontal fashion.

A wheeled implement including a leveling system, said implement having a flexible three-piece frame adapted to support ground-engaging tools, a hitch structure pivotally connected to said frame for movement about a transverse axis and extending forwardly to a forward end connectible to a traction vehicle, and support wheels mounted on said frame and moveable between transport and working positions, said leveling system comprising:

• (a) four wheel lift cylinders attached to said frame for raising and lowering said support wheels;
• (b) fore-and-aft leveling means for stabilizing said frame during transport and for maintaining said frame substantially parallel to the ground during both transport and working positions, said fore-and-aft leveling means being located approximately in the middle of said three-piece frame and in a forward portion thereof, said leveling means including a first support arm pivotally attached at one end to a front portion of said frame, a second support arm securely attached to a point on said frame rearward of said first support arm, a hydraulic cylinder attached to said first support arm and being coaxially aligned with a spring assembly which is attached to said second support arm, said hydraulic cylinder being connected in parallel with at least two of said wheel lift cylinders to retain said frame substantially parallel to the ground during movement of said frame between said transport and working positions and to hold said frame stable during transport, and said spring assembly cooperating with said hydraulic cylinder to permit flexible movement of said frame while said implement traverses over uneven terrain;
• (c) a mechanical link connected between said first support arm and said hitch structure for angularly retaining said hitch structure relative to said front portion of said frame to accommodate a drawbar hitch positioned at various heights on said traction vehicle;
• (d) fluid supply means for supplying pressurized fluid to said wheel lift cylinders and to said fore-and-aft hydraulic leveling cylinder;
• and
• (e) flow dividing means for dividing the volume of said pressurized fluid equally between said wheel lift cylinders and said fore-and-aft hydraulic leveling cylinder such that said frame can be raised and lowered with respect to the ground in a substantially horizontal fashion.