Front drum adjustment mechanism for a feederhouse on an agricultural combine

In an agricultural combine having a frame adapted for movement across a field of crop, threshing and separating mechanisms mounted on said frame to thresh and separate grain from crop material, a header for severing crop material from the field and consolidating it, a feederhouse interconnecting said frame and said header for supporting said header and transporting the crop material from said header to said threshing and separating mechanisms, and a motor and transmissions mounted on said frame for providing rotational movement to said wheels and operative power to said header, feederhouse, and threshing and separating mechanisms, the improvement comprising:

• said feederhouse includes two elongate opposing first and second side sheets, a top and an opposing floor fitted together to form a generally elongate box with opposing front and rear openings;
• said first side sheet having inside and outside surfaces, and a generally rectangular adjustment aperture therethrough;
• a crop conveyor supported within said feederhouse between a front drum and a rear drum, said front drum being adjacent said front opening of said feederhouse and said rear drum being adjacent said rear opening of said feederhouse and pivotably supported by said frame about a first axis generally perpendicular to the direction of movement of said combine;
• an elongate drum arm having first and second opposing ends;
• said front drum rotatably affixed to said drum arm adjacent said first end thereof;
• said second end of said drum arm pivotably affixed by a pivotable mounting to said first side sheet about a second axis generally parallel to said first axis such that said front drum may be moved toward and away from said floor;
• and
• an adjustment mechanism including an adjustment plate adjacent said outside surface and affixed to said pivot arm via a connector extending through and slidable within said adjustment aperture, said adjustment plate of such dimensions that it is larger than said adjustment aperture no matter what the position of said connector inside said adjustment aperture;
• and
• a cam adjustably affixed to said outside surface of said first side sheet adjacent to and in contact with said adjustment plate, said cam is polygon-shaped with multiple sides functioning as cam surfaces and is rotatably affixed to said first side sheet about an off-center axis such that rotation of said cam adjusts the position of said drum arm, whereby adjustment of said cam selectively moves said adjustment plate and said pivot arm.