A brake is a contrivance for retarding or arresting motion by means of friction. In machinery it generally consists of a simple or compound lever, that may be pressed forcibly upon the periphery of a wheel, fixed upon a shaft or axis. A similar contrivance is attached to motor vehicles and railway carriages, but continuous brakes applied to every pair of wheels in a railway train, and operated by air either by the compression or vacuum method, are now generally used on railways. By the compression method, of which the Westinghouse brake is an example, the air is compressed by a pump on the locomotive and conveyed by pipes and tubes to cylinders which are under each car, and the pistons of which act on the brake-levers. In the vacuum method, exemplified in the Loughridge brake, the air is exhausted from the device beneath the car, and the pressure of the atmosphere operates the brake-levers. Research Brake
Abbreviations
SciTech
Research Brake