Novel design for the adjustable knock-out mechanism with a Roberts linkage

This article presents a new adjustable knock-out mechanism of a bolt former with a Roberts linkage and an adjustable crank-rocker linkage. The design requirements of the new mechanism are based on the analysis of an existing adjustable knock-out mechanism. The new adjustable knock-out mechanism mainly consisting of a Roberts linkage, and an adjustable crank-rocker linkage is proposed to meet the specified requirements. The path of the knock-out screw is approximately a straight line and the method presented is illustrated by an example.