Lowering upender design and synthesis

A rigorous mechanism design approach was used to optimize a six-bar linkage fulfilling the task of lowering a 5-ton roll of paper from one elevation to another while changing its orientation by 90 degrees. This problem was motivated by a need in paper mills to improve upon the poor space and efficiency attributes of the current mechanism. The design approach used the problem statement to develop explicit design specifications. A formal type synthesis process was used to determine the optimal class of mechanism to meet the defined design specifications. This process yielded two classes of advantageous mechanisms, the Watt I and Stephenson III, which were further developed by dimensional synthesis. Using different approaches to the dimensional synthesis technique allowed three different mechanisms to be created that all moved the paper roll through the design positions. Distinguishing the best suited mechanism required a performance evaluation of static and dynamic states in addition to geometric evaluation. This work resulted in the optimization of a Stephenson III six-bar mechanism, generated by creating a path with prescribed timing base four-bar and an auxiliary motion control dyad, that met all of the design specifications.