Allis-Chalmers Texrope Drive Selector slide rule, used to determine the number of belts required for a drive system. This specific slide rule is a vintage tool produced by Allis-Chalmers Manufacturing Company, likely in the mid-20th century. It functions as a specialized calculator for engineers and technicians to design and troubleshoot Texrope V-belt drive systems, which were a popular power transmission method.
The various scales and tables on the slide rule allow users to input parameters like motor horsepower, belt speed, and sheave diameters to determine the correct number of belts needed for a specific application. Similar to other slide rules of its era, it provided a quick and efficient way to perform complex calculations without the need for modern electronic calculators.