Patent ID: 7647755

Claim:
A pull-type crop harvesting machine comprising: a frame mounted on ground wheels for movement across ground carrying a standing crop for harvesting; a header mounted across a front of the frame so that the frame carries the header into the standing crop for cutting the standing crop and converging the cut crop into a crop discharge; a hitch arm extending from the frame to a forward end of the hitch arm arranged for attachment to a hitch coupling of a tractor by which the frame and the header are towed across the ground; the hitch arm being connected to the frame by a pivot coupling arranged to provide pivotal movement about a generally upright axis so that the hitch arm is movable between a first position and a second position; and a hydraulic cylinder connected so as to actuate movement of the hitch arm relative to the frame between the first and second positions, the cylinder comprising: a cylinder body; a piston slidable within the cylinder body; a piston rod projecting from a first end of the cylinder body; a cylinder coupling at a second end of the cylinder body connected to one of the hitch arm and the frame; a rod coupling at an outer end of the piston rod connected to the other of the hitch arm and the frame such that movement of the piston in the cylinder body causes said movement of the hitch arm relative to the frame a first port arrangement adjacent the second end of the cylinder body connected to a first hydraulic supply line such that hydraulic fluid supplied through the first hydraulic supply line is communicated to the cylinder body through the first port arrangement on a side of the piston to drive the piston to the first end of the cylinder body; a second port arrangement adjacent the first end of the cylinder body connected to a second hydraulic supply line such that hydraulic fluid supplied through the second hydraulic supply line is communicated to the cylinder body through the second port arrangement on a side of the piston to drive the piston to the second end of the cylinder body; the rod coupling being adjustably mounted on the rod such that the position of the rod coupling on the rod can be moved to change the distance of the piston from the rod coupling and thus to change the position of the rod coupling relative to the cylinder coupling when the piston reaches the first end of the cylinder body; and a stop member mounted on the piston rod and arranged to engage the first end of the cylinder body when the piston approaches the second end of the cylinder body, the position of the stop member on the piston rod being adjustable independently of the rod coupling so as to change the position of the rod coupling relative to the cylinder coupling when the stop member reaches the first end of the cylinder body; the hitch arm and the frame being arranged such that the first position of the hitch arm is defined by the piston reaching the first end of the cylinder body and such that the second position of the hitch arm is defined by the stop member reaching the first end of the cylinder body.