Image Number 4 for United States Patent #4424965.
Paper sheet products are conveyed in shingled array at speeds up to 60,000 pieces per hour in the grasp of individual normally closed clamps precisely spaced on a chain link drive and timed for on-line processing at various stations. Thus, clamp tractor units have wheels mating with a U-channel track and rolling at low friction along the track, which may be bent and twisted to conform to a desired pathway in a plant between processing stations. Entrance and exit stations along the transit path provide mating cam surfaces at the station and on the clamp for opening the clamps to receive the products or to discharge them on further processing or transit equipment. Simplified equipment with more reliable pickup and release controls assuring individual product timing and positioning is accomplished by spring biased jaws pivotable by simple cams into open product receiving and closed product gripping and registration positions.