GB382642A - Improvements relating to regulator valve apparatus for locomotives - Google Patents

Abstract

382,642. Locomotive regulator valve apparatus. SUPERHEATER CO., Ltd. and ROBINSON, E. A., Bush House, Aldwych, London. June 29, 1931, Nos. 18718/31 and 7705/32. [Class 79 (i).] Comprises the combination, in locomotive regulator valve apparatus, with a pilot valve 4 adapted to be opened to supply steam from a supply chamber 1 to a balancing chamber 3 of the valve housing to place the main valve or valves 5 in balance as to steam pressures, of means whereby a small quantity of steam can be supplied directly to the engine valve chests or cylinders without opening a main valve, such quantity being capable of regulation by manipulation of the regulator lever. Steam can thus be supplied for " drifting " purposes to prevent the formation of a vacuum in the engine cylinders ; where a superheater is fitted the steam thus supplied may pass through the superheater and prevent overheating of the elements. In the construction shown in Fig. 1 the valve housing is provided with a " drifting " chamber 9 and the pilot valve 4 is formed with a piston 12 adapted to seal the upper part of a partition 10 between the chambers 9, 3. When the pilot valve is raised slightly by means of the actuating shaft 6 steam is admitted from the supply chamber 1 to the chamber 9 but is prevented by the piston 12 from passing to the balancing chamber 3. Steam can then pass from the chamber 9 through a pipe 13 and branch pipes 14 to the main steam pipes 15 leading to the engine cylinders, The ends 16 of the pipes 14 are turned in the direction of the flow of steam in the main pipes 15 and are located near the ends of pipes 17 leading from the force feed of the lubricator, so that the drifting steam supplied by the pipes 16 tends to atomize or emulsify the oil supplied by means of the pipes 17. When it is desired to open the main valve or valves 5 the pilot valve is raised by the shaft 6 until the piston part 12 is clear of the partition 10, and steam can pass along channels 11 in the pilot valve stem to the balancing chamber 3 thus balancing the pressures on the main valve ; further operation of the shaft 6 then lifts the main valve in the usual manner, and admits steam to the delivery chamber 2 leading to the main steam pipes. In the construction shown in Fig. 4 the pilot valve 4 works in a sleeve 26 having ports 27, 28 leading respectively to the balancing chamber 3 and the delivery chamber 2. When the pilot valve is raised slightly a small amount of steam enters the sleeve 26 and passes through the ports 27, 28 to the chambers 3, 2 ; the steam thus admitted to the chamber 2 passes through the main steam pipes to the cylinder. When the main valve (not shown) has been opened the pilot valve will have been lifted to such an extent that a piston head 12a thereon will have closed the ports 28. Means may be provided in the driver's cab to indicate the position to which the regulator lever should be moved to raise the pilot valve only sufficiently to supply steam for drifting purposes, e.g. a catch or trigger may co-operate with a recess in the regulator quadrant. A modification is described in which the invention is applied to an existing valve housing, the drifting steam pipe 13 being connected to a chamber formed by a sleeve surrounding the pilot valve. Specifications 296,513, 330,346, [both in Class 135, Valves &c.], and 351,088, [Group XXIX], are referred to.