Patent GB-333272-A (GB)
Title: Improvements in or connected with auxiliary engines and controls for steam locomotives
IPC: F01B25/00
Filed: 1929-05-01
Abstract: 333,272. Stone & Co., Ltd., J., and Carroll, W. P. May 1, 1929. Hand, foot, and like gear.-Steam-operated control mechanism for a locomotive booster comprises a pilot valve controlling the admission of steam to a preliminary throttle valve and to a clutch cylinder for putting the booster in gear with the locomotive axle, combined with one of the following features :-(a) the mounting of the preliminary throttle valve and a stop cock control for the pilot valve as a unit on the boiler so that one boiler pad serves for the two, (b) the provision of an idler valve associated with the pilot valve for cutting off the supply of steam to the clutch cylinder when it is desired to run the booster for test or examination, and (c) the provision of a chambered steam chest, a controllable leak connection between the chambers for enabling pressure to build up slowly for operating a motor device to bring about closing of the drain valves of the booster cylinder, and a valve opening automatically for quick exhausting of the motor device when the drain valves are to be opened. The booster engine shaft 4 carries a gear wheel 3 gearing with a wheel 5 on a rocker 6 which can be moved about a pivot 7 to bring the wheel 5 into mesh with a gear wheel 2 on the locomotive axle 1. The rocker is normally held in the out of gear position by means of a spring 10 and is rocked to engage the gears by a power cylinder D. Steam is admitted to a pilot valve A by means of a hand-controlled stop cock B. The pilot valve is controlled by a latch b which is connected to the ordinary locomotive reversing gear and simultaneously closes a valve e<2> and opens a valve i, thus allowing steam to pass from the stop cock B through a pipe B' and valve i to pipes C', D' leading respectively to a preliminary throttle valve C and to the clutch cylinder D. The steam in the pipe C' acts on a piston p and opens a valve u, thus admitting a small quantity of boiler steam through a pipe w having a constriction z to the main steam pipe x of the booster cylinders y. The booster engine is thus warmed up and set going slowly, while at the same time the clutch cylinder D is operated by the steam from the pipe D' and puts the booster in gear with the axle 1. When the clutch piston has reached the end of its stroke a port 12 in its cylinder is uncovered and steam passes through a pipe 14<a> to a cylinder G thus operating a piston 15 which opens the main throttle alve 21 of the booster through rods 23, 26 and a lever 25. A drain valve 17<a> is provided for the clutch cylinder. In a modification the return of the gear rocker 6 to the out of gear position is assisted or effected by a separate power cylinder. In another modification an additional reversing pinion is provided on the gear rocker and the valve A is divided into three parts, one of which controls the stearn supply to the booster cylinder and is always operated by the latch b, while the other two are operated one at a time by the latch and control the admission of steam to either end of the clutch cylinder. The stop-cock B and the preliminary throttle valve C are mounted on the same boiler pad as shown. When the latch b is released the valve i is closed and the valve e<2> is opened thus connecting the pipes C<1>, D' to the exhaust pipe, k through the valve e<2> and a pipe m. If it is desired to test the booster while the locomotive is stationary an idler valve E is operated to close the inlet to the pipe D' so that steam can pass only to the preliminary throttle valve C. A small port 52 may be provided in the preliminary throttle valve to allow a small quantity of steam to pass from the boiler to the booster to keep the latter warm in cold weather.