Auger with tapered flighting

In a agricultural harvesting header for severing crops from the ground, the header having generally opposing first and second side walls, a crop severing apparatus at a front edge of the header extending between the side walls, and a discharge zone having a width being defined by first and second edges, the discharge width being considerably less than that of the crop severing apparatus, and a crop conveying apparatus for transversely converging severed crop material from the width of the severing apparatus through the discharge zone and move the crop without conditioning, unobstructed rearward of the header, the improvement in the conveying apparatus comprising

• an elongate auger with a first end and a second end, said auger being rotatably connected to and supported by the header and extending generally between the first and second side walls;
• a left-hand flighting portion of said auger extending substantially between said first end and a point at least midway between said first and second edges of the discharge zone;
• a right-hand flighting portion of said auger extending substantially between said second end and at point at least midway between said first and second edges of the discharge zone;
• wherein said left-hand and right-hand flighting portions have a generally constant first outside diameter in an axial zone extending along the auger length from said first end to said first edge and from said second end to said second edge, and a variable outside diameter extending along the auger length from said first and second edges to at least a point mid-way between said first and second edges creating a tapered region between said first and second edges with a minimum diameter defined by the extension of the flighting occurring generally midway between said first and second edges.

A method for forming a windrow of a specialty, seed-bearing crop using a cutting header propelled by a crop harvesting machine comprising the steps

• providing a cutterbar transversely disposed across a forward edge of the header to sever standing crop material, the cutterbar defining a cutting width;
• providing a discharge opening in the header for rearwardly ejecting severed crop material onto the ground, the discharge opening having a discharge width substantially less than the cutting width;
• providing a transverse crop conveying auger for converging severed crop material from the cutting width to the discharge width, the transverse auger further comprising:
• an elongate central core supported by the header for rotation about an axis, the central core having a first end and a second end;
• a first portion having left-handed flighting radially extending from the central core to define an outer diameter, the first portion axially extending along the core from a position adjacent to the first end and continuing inwardly along the central core;
• a second portion having right-handed flighting radially extending from the central core to define an outer diameter generally equal to the outer diameter of the first portion, the second portion axially extending along the core from a position adjacent to the second end and continuing inwardly along the central core;
• a central portion disposed axially along the central core between the first and second portions and generally co-extensive with the width of the discharge opening, the flighting from said first portion and the second portion axially extending inwardly along the core to a central intersection, the radial extension of the flighting in the central portion being tapered as the flighting approaches the central intersection;
• propelling the harvester across the ground to sever a standing crop, and
• rotating the auger to gently convey severed crop material toward the discharge opening whereby the crop is deposited on the ground directly from the auger in the form of a generally uniform windrow.