Self-cleaning sprocket

A self-cleaning sprocket for use with an endless belt having internal lugs for engaging said sprocket, comprising a body of material having a generally cylindrical outer periphery, said sprocket having a generally cylindrical central base portion and a plurality of circumferentially spaced lug receiving pockets above and below said central portion, said upper lug pockets being open to the axial end of the sprocket and having a bottom face sloping upwardly inwardly from its intersection with said outer periphery, a generally axial lug engaging side face intersecting said bottom face and parallel to a radial line within the portion of the sprocket between said side face and the next adjacent pocket, and a radially inner face intersecting the side and bottom faces and sloping radially inwardly from the bottom face toward the upper end of the sprocket, the intersections between said faces being filletted to round the corners thereof.

In a crop gathering unit of the type having at least one crop passageway and an endless gathering belt having internal lugs running adjacent said passageway, said belt being entrained about a sprocket adjacent the rear end of the passageway, said sprocket being mounted above its supporting structure, the improvement wherein said sprocket is self-cleaning and comprises a body of material having a base portion generally cylindrical about the rotational axis of said sprocket and a plurality of ribs extending axially upwardly from said base portion, said ribs converging radially from the outer periphery of said base portion to a hub portion and defining with said base portion a plurality of lug receiving pockets, said pockets opening upwardly to the axial end of the sprocket, the bottom face of said pockets comprising said base portion sloping upwardly from the outer periphery to said hub portion and said hub portion sloping radially inwardly from said base portion toward the open axial ends of said pockets, the intersections in said pockets between said base portion and said hub portion being filletted such that upon said belt lugs entering said pockets, the flow of debris from said base portion onto said hub portion is facilitated.

In a crop gathering unit of the type having at least one crop passageway and an endless crop gathering belt and running adjacent said passageway having internal lugs, said belt being entrained about a sprocket rotatably mounted adjacent the rear end of the passageway, the improvement wherein said sprocket is self-cleaning and comprises a body of material having a base portion generally cylindrical about the rotational axis of said sprocket and a plurality of ribs extending axially from said base portion, said ribs converging radially from the outer periphery of said base portion to a hub portion and defining with said base portion a plurality of lug receiving pockets opening axially of said sprocket and of a considerable larger size than said belt lugs, the bottom face of said pockets comprising said base portion sloping axially toward said open end from said outer periphery toward said base portion such that a relatively close fit of said pocket bottom face and said belt lug is provided, and the pitch of said pockets being slightly greater than the pitch of said belt lugs along the line of engagement of the belt and sprocket such that upon said belt being operated with no crop load, said belt is driven by frictional engagement with said base portion periphery and upon said belt being loaded by crops said belt is driven by the engagement of the ribs and lugs.