Timing belt for disc cutterbars

Abstract

A disc cutterbar for use on a harvesting implement, such as a disc mower-conditioner, is driven by an endless timing belt entrained around toothed sprockets corresponding to each disc cutter within the transmission casing. The positive engagement between the toothed timing belt and the corresponding toothed sprocket provides a means for timing the rotation of adjacent disc cutters to minimize the possibility of interference between rotating knives. The toothed timing belt, however, is capable of movement relative to the toothed sprocket should the corresponding disc cutter become restricted in its rotation, such as by impact with a substantial object. To provide overlapping paths of travel of knives on adjacent disc cutters, yet prevent interference therebetween, alternating disc cutters are obliquely mounted on the transmission casing so that the path of travel of the knife thereon is within a plane space vertically within the overlap area relative to the path of rotation of the knives on the adjacent disc cutters. A spring-loaded guide urges the timing belt into engagement with the toothed sprocket under conditions where the timing belt is attempting to move away from the toothed sprocket.