Patent ID: 8955297
Filing Date: 2015-02-17
Classification: A01D

Abstract:
1. A snapping unit for heads of harvesting machines, comprising a pair of counter-rotating snapping rolls and a support and motion transmitting unit with which the snapping rolls are associated so as to cooperate with each other when placed into rotation around their longitudinal axis, each snapping roll comprising a body wherein a cylindrical rear portion and a frustoconical front portion are defined, a side wall of the body being provided on its outer surface with longitudinal helical grooves defining helical protrusions ending in corresponding helical ridges capable of penetrating the helical groove defined between the helical ridges of the adjacent roll during rotation of the two snapping rolls, wherein the helical grooves and correspondingly the helical protrusions and the respective helical ridges have a pitch at least equal to a total length of the corresponding roll and extend on at least part of the frustoconical portion, wherein small grooves having a substantially “U” shaped cross section are provided at the base of the snapping roll close to its rear end and inside the longitudinal helical grooves, said small grooves being arranged substantially in the middle of at least some of the longitudinal helical grooves so that the ridges of the adjacent snapping roll enter between the legs of the “U” shaped small grooves during rotation of the two snapping rolls.