Abstract: A mechanism for forcing apart the upper and lower rolls in a crop conditioning apparatus is disclosed wherein the torsion bar operably associated with the upper conditioning roll to assert a biasing force thereon to urge the upper roll toward engagement with the lower roll is anchored against one of the lift arms pivotally supporting the crop gathering header for generally vertical movement relative to the ground. The anchor is in the form of a connecting link pivotally interconnecting one of the lift arms and an anchoring arm forming a portion of a hub assembly engaged with the torsion bar to effect rotation thereof to create the biasing forces exerted on the upper roll. The movement of the lift arms to raise the crop gathering header relative to the ground causes a reverse rotation of the hub assembly and the engaged torsion bar to lessen the biasing force exerted thereby.

Abstract: An improved knife section for reciprocating mower is disclosed wherein the improved knife section is constructed from less material than a standard knife section. The thickness of the improved knife section is made substantially equal to the thickness of the material of a standard knife section by forming convolutions in the body. A reinforcing ridge parallel to the cutting edge further improves the rigidity and strength of the improved knife section. The reinforcing ridge extends rearwardly beyond the cutting edge to encircle the rivet holes to allow for the inclusion of countersunk areas permitting the rivet heads to fit within the plane of the knife section, thereby producing a substantially uniform top surface. An extension of the countersunk area below the bottom surface of the knife section can interfit an embossed depression formed around the rivet hole in the support bar, resulting in an interlock between the knife section and support bar to reduce shearing stresses within the rivet.