Cutter Having Customizable Ideal Mechanical Advantage at Each Point in the Cutting Stroke

摘要

A powered shearing mechanism or cutter is disclosed that comprises an asynchronous double class 1 lever and a linear actuator that uses two ganged wheels to pry the effort portion of both levers open and close the jaws. The wheels move linearly—with the distance between them kept constant—and roll along—and exert force against—parts of the levers called “bearing surfaces.” The bearing surfaces are non-planar and reflectively symmetric and their profile is customized to provide any desired ideal mechanical advantage for the cutter. In accordance with the illustrative embodiment, the profile of the bearing surfaces is a circular arc, which provides a bearing surface which is easy to precisely fabricate and that provides a fairly constant ideal mechanical advantage at each point as the cutter's blades cut through the material.