Self-propelled windrower tailwheel non-zero caster for stability

A self-propelled agricultural crop harvesting machine comprising:

• a main frame extending along a longitudinal axis between front and opposing rear ends and adapted to support a removable crop-engaging header on said front end thereof;
• a transversely spaced-apart front wheel pair supporting the front end of the main frame;
• an engine and drive system supported by said main frame to supply motive power to drive said front wheel pairs at independently adjustable rates, differences thereof enabling control of direction of travel of the harvesting machine;
• laterally extending elongate beam portions connected to the main frame at a position spaced longitudinally from the front wheel pair, each having a distal end;
• a rear wheel pair supporting the rear end of the main frame, one of the rear wheel pair mounted on one of the respective distal ends of the beam by a caster assembly, each caster assembly having a pivot member defining a generally upstanding swivel axis mounted in a swivel support;
• and
• a caster angle adjuster assembly disposed in each of the laterally extending beam portions, each assembly having a fixed adjuster portion disposed toward a proximal end of the laterally extending beams portions and a moveable portion disposed toward the distal end of the laterally extending beams portions, the movable adjuster portion rotatable about the longitudinal axis of the beam portion enabling rotation of the swivel axis in a plane parallel to the longitudinal axis to a position angled from vertical;
• and
• wherein each caster angle adjuster mechanism further comprises an indexing structure wherein the fixed and movable adjuster portions may be selectively fixed in one of a plurality of angular positions corresponding to an angular displacement of the swivel axis from vertical.

A self-propelled agricultural crop harvesting machine Comprising:

• a main frame extending along a longitudinal axis between front and opposing rear ends and adapted to support a removable crop-engaging header on said front end thereof;
• first and second transversely spaced-apart drive wheels supporting the front end of the main frame;
• an engine and drive system supported by the main frame to supply motive power to drive the first and second drive wheels at independently adjustable rates, differences thereof enabling control of direction of travel of the harvesting machine;
• first and second non-driven caster wheels supporting the rear end of the main frame, the first and second caster wheels mounted on respective caster assemblies, each caster assembly having a pivot member mounted in a swivel support member defining a swivel axis, the swivel axis being angled from a vertical axis in a plane parallel to the longitudinal axis;
• laterally extending elongate beam portions connected to the main frame, each having a proximal end connected to the main frame and a distal end connected to a respective caster assembly;
• and
• a pair of caster angle adjuster assemblies, one disposed in each of the laterally extending beam portions, each assembly having a fixed adjuster portion disposed toward the proximal end and a moveable portion disposed toward the distal end, the movable adjuster portion rotatable about the longitudinal axis of the beam portion enabling rotation of the swivel axis in the plane parallel to the longitudinal axis to a position angled from vertical wherein each caster angle adjuster assembly has an indexing structure such that the fixed and movable adjuster portions may be selectively fixed in one of plurality of angular positions corresponding to an angular displacement of the swivel axis from vertical.