Anti-slip device for compressed air brakes, particularly for rail vehicles

Claim 1

An antiskid device for a compressed air brake of a railroad vehicle, comprising a brake cylinder, a control distribution valve for filling and emptying said brake cylinder, a deceleration sensor responding to the deceleration of a wheel during braking on a slippery rail, a compressed air holding valve, means closing said holding valve when the air pressure drops to a predetermined value, a relay valve having a first chamber connected to said brake cylinder, a second chamber in said relay valve connected to said holding valve, a valve disk in said relay valve actuated by said deceleration sensor, said valve disk in a first position separating said first chamber from said second chamber and in a second position separating said brake cylinder from said control distribution valve and connecting it to said second chamber for a rapid lowering of air pressure in said brake cylinder to the air pressure predetermined by said holding valve in the case of a brief response of said deceleration sensor during the braking action on a slightly slippery rail, an exhaust pipe connecting said relay valve and said holding valve, and a throttling constriction in permanent communication with the atmosphere positioned in said exhaust pipe, so that when said holding valve closes to said predetermined value some pressure remains in the brake cylinder prior to the re-application of the brakes, said residual pressure being exhausted through said throttling constriction in the case of a long response of said deceleration sensor during the braking action on a very slippery rail.