ESSENTIAL PARTS OF THE WESTINGHOUSE AUTOMATIC AIR-BRAKE.
The prominent features of the Westinghouse automatic air-brake consist of the following leading parts: An air-pump, placed on the locomotive, is operated by a steam cylinder, which forces air into an iron drum or reservoir placed under the deck, or in any other convenient part about the engine. The air is compressed to the density considered necessary for the kind of train the locomotive usually pulls.
In the cab, located conveniently to the hand of the engineer, is the engineer’s brake-valve, commonly called the “three-way cock,” which regulates the flow of air from the main reservoir into the main brake-pipes for supplying the auxiliary reservoirs with air. This valve applies the train-brakes by letting the air escape from the main brake-pipes, and releases them by again admitting the pressure of air into the pipes.
From the main reservoir, the main brake-pipe connects with the engineer’s valve, and thence along the train, supplying all the brakes with the air required.
Under the floor of each car is fastened an auxiliary reservoir, which holds a supply of air necessary for operating the brakes on that car. So each car carries its own supply of air.
Connected with each car-truck is a brake-cylinder, in which is operated a piston that applies the brake. The brake-levers connect with the piston-rod in such a manner, that, when the piston is forced out by the air-pressure, the brake is applied.
Attached to the auxiliary reservoir is the triple valve, whose action connects the air-cylinder with the auxiliary reservoir.