Abstract: A finish topper for bulb crops having a plurality of longitudinal, parallel, generally horizontal, spaced-apart moving belts for conveying bulbs through the apparatus. Adjacent belts are driven at different linear speeds. In a preferred embodiment, alternate belts are replaced by stationary rails to maximize the speed differential. Below and adjustably close to the belts is a driven rotating blade for cutting the bulb stems and also exerting a downwards draft of air through the belts. Onions introduced onto the belts are conveyed through the apparatus by the belts, and the differential in speed between the moving belts and stationary rails causes the bulbs to rotate and gyrate randomly as they are being conveyed. Because the belts are spaced apart, the bulbs assume momentarily an attitude to permit the uncut stems of bulbs to extend downwardly between the belts. The bulbs are retained on their shoulders on the belts in inverted posture.

Abstract: A sickle bar cutter assembly for use on crop harvesting machines includes a mechanism for automatically adjusting the relationship of the cutter hold downs to the cutter knives to ensure that proper scissors action of the cutter knives produces a clean cut of the crop being harvested. The mechanism includes a member for biasing the cutter hold downs against the cutter knives and a member to which the cutter hold down is mounted and about which it pivots. At least those portions of the cutter hold downs contacting the cutter knives are hardened.

Abstract: A machine for harvesting onions utilizes a blower which provides a stream of air through a duct, having an opening across which the onions pass and are topped. The blower has a bladed fan in a cylindrical housing open at both ends. The fan blades are supported by arms which, with the blades, define a support truss for each blade in the form of a triangular structure, having arms meeting at an apex connected approximately midway of the end of the cylindrical housing and a base provided by the blade to which the arms are connected. A rigid support is provided together with an enlarged and substantially unobstructed intake passageway for air along the axis of rotation of the fan which is pressurized and forced through the duct, using less horsepower and fuel than conventional fans of like size and air flow.

Abstract: A harvesting machine is especially adapted for automatic topping and loading of crops, such as onions. The crops are gathered from the field and elevated on a conveyor to a region adjacent to which a topping device (a sickle) is disposed. The conveyor has openings to permit the passage of air which is blown from a blower. The openings are sufficiently narrow to support the crop while allowing rocks, clumps and other debris to drop therethrough. The blower is offset from the topping region. A duct extends tangentially and upwardly from the blower to direct a laminar (non-turbulent) flow of air through the conveyor openings for extending the tops. The duct has a wall at the bottom thereof which faces the region. This wall has a passage, preferably with louvers which extend generally vertically. A negative pressure is developed adjacent to these louvers and a generally laminar flow of air passes upwardly through the louvers and enhances the laminar flow through the conveyor in the region where topping occurs.