Patent attributes
A head shaft assembly has a center tube, an end tube, a collector sprocket and a collar. The center tube has drive and driven ends. The center tube has a center tube diameter. The end tube has a key extending longitudinally along an outer surface and inner and outer ends. The key defines a key length and the end tube has an end tube diameter. The collector sprocket is mountable to the end tube and rotationally secured to the end tube by the key. The collar is hollow between a first end and a second end. The center tube diameter is substantially the same as the end tube diameter and the drive end is proximate to the inner end. The drive end and the inner end are positioned within the collar between the first end and the second end. The collar fixes the center tube to the end tube.