Reciprocating sawing machine with toothed drive sectors - has return stroke faster than working stroke due to varying gear ratio

摘要

The reciprocating sawing machine has the blade moved at a uniform speed during the working stroke, and a higher speed on the return stroke, to give maximum output. The saw can be attached to a rocker lever equipped with an assembly of toothed sectors (3, 4) with which the driving pinion (7) meshes. The sector with the greatest radius is used on the working stroke and that with the smallest on the return stroke, thus speeding up the return stroke. The sector assembly can be slid along the rocker lever so as to reverse the drive, and it can be secured to it by two links forming a variable parallelogram with the minimum of friction.