US1475432A - Valve for single-chamber air-pressure brakes - Google Patents

Description

NOV. 27, 192 1,475,432

W. HILDEBRAND VALVE FOR SINGLE CHAMBER AIR PRESSURE BRAKES Filed April 10 1923 Patented Nov. 27, 1923.

entree stares iavaisz WILHELM HILDEBBAND, or BERLIN, ensiannv, nssleno'a To HAIiTDEL-MAAT- SCHAPIPIJ' H. ALBERT DE BABY a 00., or AMSTERDAM, NETHERLANDS.

VALVE FOR SINGLE-CHAMBER AIR-PRESSURE BftfsKEs.

Application filed April 10, 1322. Serial No. 631,141,

To all whom it may concern Be it known that I, VVILHELM HILDE' BRAND, a citizen of the German Republic,

residing at 9-17, Neue Bahnhofstrasse, Lichtenberg O. 112, Berlin, Germany, have invented certain new and useful Improvements in Valves for Single-Chamber Air- Pressure Brakes, of which the following is a specification. c 1

This invention relates to valves for single chamber air pressure brakes, its object being to provide in addition to the graduated increase of the braking action means for obtaining a graduated reduction thereof, that is to say, a step by step release of the brake, while avoiding the difficulties arising from the division of the auxiliary air reservoir into two chambers by a braking piston of large diameter and frictional resistance as described in the prior United States patent specification No. 1325, 177.

According to this invention a regulating container divided into two chambers of variable capacity is inserted into the connection betweenthe train pipe and the auxiliary air reservoir, and in the said. container is provided an easily working piston mounted on a common piston rod with asmaller counter piston working in a guide tube or recess. The chamber in which the counter piston is located is connected with the chamber of the brake filling valve, and the other chamber of the regulating container is in direct communication with the auxiliary reservoir, and in communication through the sald filhng valve with the train pipe.

In order that the saidinvention may be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawings, in which Figure 1 shows diagrammatically the ap paratus in the release position.

Figure 2 shows the sameapparatus in the position assumed when applying the brake.

The reference letter 6 indicates the train auxiliary reservoir a when the valve 2' is in theposition shown in Figure 2 the valve 39 in the valve chamber (Z then closing the connection between the brake cylinder 0' and the open air through the recess a in the til) valve 2', the pipe m, and the recess 76 in the ferential piston comprising a larger piston g and a small counter piston h, this chamher 8 being constantly in communication with the interior of the casing (Z of the filling valve 29. In the normal position shown in Figure 1 pressure in the chambers s and t is equalized through a filling grooveadjacent to the piston g.

When 'the pressure in the train pipe 6 is reduced to applythe brake, the pistons of the valves 71 and 39 will pass into the posi-v tions shown in Figure 2, when air from the reservoir a acts on the piston in the brake cylinder 0, the connection between the pipes r and g is interrupted and the reduction of pressure in the reservoir a and chamber t allows the piston g to move to the left beyond its filling groove w, the counter piston h of course partaking in this movement. If

the pressure in the train pipe e has only been slightly reduced so that in these movements the pressure in the auxiliary reservoir 0 falls below that in the train pipe, the distributing slide valve 71 will be forced back into the release position, but the connection between the brake cylinderc and the open air is not reestablished because the filling slide valve p remains in the brake on position owing'to the pressure in the chamber 8 being maintained by the movement of the counter piston h at a higher level than that in the chamber t. By a further reduction of the pressure in the train pipe the slide valve 2' can again be brought into the brake on position to place the auxiliary reservoir in communication with the brake cylinder.

For the purpose of obtaining a graduated release of the brakes, the pressure in the train pipe is so much increased that it somewhat exceeds the pressure in the auxiliary rese voir. The dist hating valve 2' and fillin valve then pass into the release pesition, so that the air begins to escape from the brake cylinder, but at the same time the chamber 5' of the regulating container is connected with the train pipe 6 through the pipe 9, recess Z and pipe 1", hence the pres- E L1I'6 in the chamber at increases and forces the difierential piston g h to the right, causa pressure in the chamber .9 which, owing to the presence of the counter piston it errceeds the train pipe pressure and the valve 7) is thus forced downward, whereby the re leasing process is stopped and the release cut-off position induced. In order to effect the complete release oi the brake the full poise of pressure at both sides or the piston g.

What I claim and desire to secure by Letters Patent of the United States is 1.1n a single chamber compressed air brake, a train pipe, an auxiliary air reservoir, a brake cylinder, a connection between said reservoir and said cylinder, a connection between said cylinder and the atmosphere, a distributing valve controlling both said connections, a regulating container comprising two chambers of variable capac tween said cylinder and the atmosphere,

said piston being; adapted to control the movements of said filling valve. a

2. Distributing means'for sin le chambercompressed airbrakes characterized by the facts that controlling device is provided for applying and releasing the brake and another controlling device is provided for filling the brake, and thatfor the purpose of permitting a graduated release between the auxiliary air reservoir and the filling control device there is provid container having a diiierential piston, in which container the chamberat one side of the larger piston is connected with the said auxiliary air reservoir and with the traipipe, while this latter'connection is intere rupted by the filling control valve upon application of the brake, while the chamber at the other side of the separatingpiston of the regulating container situated towards the counter piston is connected with the distributin slide valve chamber of the filling control valve.

wiLnELM HILDEBRAN Q red a regulating 1

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