Oscar E. Perrigo Change Gear Devices

Annotation

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. There were one hundred and sixty-four patents examined, and out of this mass, twenty-nine were selected as bearing directly upon the Change Gear problem; the others being for forms of variable speed devices and similar inventions, not properly coming under the head of the Evolution of the Change Gear. These twenty-nine patents have been very carefully considered and described, their special or distinguishing features illustrated and compared in a conscientious and disinterested manner, which it is hoped, will prove both instructive and useful to those who may be interested in this field of mechanical development.