GB190500209A - Improvements in Electro-magnetically Controlled Fluid-pressure Motors. - Google Patents

Abstract

209. Malan, E. de M. Jan. 4. Valves and valve-gear.-The auxiliary valves of the fluid-actuated valve-gear of motors which may be used to operate signals and points on railways are electro-magnetically controlled, an arrangement being provided for preventing the reversal of the main valve should the idle electro-magnet become accidentally energized. The main valve 5 is connected to pistons 6, 7, which move in cylinders 8, 9 communicating with the atmosphere and with the valve chest 10 by passages 36, 37 and with the cylindrical chamber 15 by pipes 26, 27. The fluid supply to the cylinders 8, 9 is controlled by electromagnetically-actuated valves 11, 12. The chamber 15 contains a double piston 17, 18 which is normally held in the central position by springs 24, 25. Leakage grooves 22, 23 put the outer ends of the cylinders in communication with the atmosphere when the piston is in either end position. In Fig. 1, the valve 11 is shown raised. The motive fluid passing through passages 36, 26 presses the piston to the right. Should the magnet become accidentally energized, the fluid would not press on the piston 7 but would flow away to the atmosphere through the pipe 27 and the groove 23. In a modification, the chamber 15 is dispensed with and extensions are provided to chambers 8, 9 in which slide plates pressed inwardly by springs. The nuts on the pistons 6, 7 press on these plates when the pistons are held in the central position. Leakage grooves are provided in the cylinders 8, 9, the action being as described above. In another arrangement, the pistons 6, 7 are held in the central position by fluid-actuated pistons contained in the extension chambers. According to the Provisional Specification, the desired exhaust to the atmosphere or return pipe may be provided by electromagnetically-operated valves, the magnets being connected up in series or in parallel with the other electro-magnets.