Harrisburg Telegraph

Measures Force Required
to Break Gear Tooth

Another triumph for automobile engineers is recorded in the development of a gear impact testing machine which actually determines the exact force required to break a gear tooth.

Heretofore, although tests of this nature have been conducted since the beginning of the industry, it has been possible to estimate only approximately the force expended, without taking into definite consideration the force left over. It is in its ability to record the latter that the machine recently perfected by the engineers of the Dodge Brothers physical laboratories differs from earlier designs. In this respect it is distinctly new and superior.

As indicated by the accompanying illustration, the gear under test is set in an iron base. A sharp steel blade is inserted between two teeth. The blade is at the end of a heavy steel arm which extends out into the path of a pendulum-like weight. When the weight falls, it drives the blade through the tooth. As the weight strikes the gear, the dial at the top to which it is attached, records the "left-over" energy. Since the force exerted by the falling mass is a known quantity, it is a simple problem in arithmetic to compute the total energy expended.

The development of this machine is characteristic of the Dodge Brothers policy of rigid tests for all materials, and dependable instruments for doing it.