8526. Mackenzie, J. W., [Poe, D. A.]. April 16. Gas and explosive - vapour engines.- The invention relates to engines for marine and land locomotion, in which the components of the explosive mixture are supplied at the required temperature and in constant proportions irrespective of the speed of the engine. In the compound engine shown in Fig. 6, a pair of high-pressure two-strokecycle single-acting cylinders a<1>, all discharge into a low - pressure doubleacting cylinder a3, in tandem with which is a double - acting low - pressure air-pump a<2> having oscillating valves g<1>, g<2> driven by a cam k<5> on the cam shaft k<1>, Fig. 7. T h e p u m p discharges through passages g<3>, g<31> to the undersides of the high-pressure pistons b<1>, b<11>, which, after further compressing the air, force it through non-return valves (not shown) to a supply reservoir I, Fig. 4. From the reservoir I, which may be cooled, charges are transferred to the explosion cylinders together with gas or explosive mixture, supplied under pressure by pumps F, and an additional charge of air previously heated by passing through a jacket on the exhaust pipe P. The first portion of the exhaust gases escapes through piston - controlled ports a<4>, a<41>, Fig. 6, to the respective sides of the low-pressure piston b<3>, while the remainder is expelled through lift valves e<1>, e<11> to a pipe P<2>, around which air from the reservoir I, for the formation of the charge, is circulated. A single set of exhaust ports a<33> controls the escape of the combustion products from the low-pressure cylinder by way of the jackets h<5> of a vaporizing-device H, Fig. 4, to the exhaust pipe P<2>. The air and gas or explosive mixture supplied to the cylinders are admitted through independent passages c<5>, c<51> and c<6>, c<61>, Fig. 7, respectively, and enter the combustion chambers through the inlet valves c<1>, c<11>. Pumps.-Gas or explosive mixture from the vaporizer H, Fig. 4, is fed to the pumps F, between the pistons f<2>, f<4>, through ports f<7>, and is transferred to the explosion cylinders through passages f<8> leading to the admission valves. Valves c<7>, e<71> actuated from the valves c<1>, c<11> by mechanism (not shown) deflect the gas or explosive mixture to the chambers f, should the pumps commence their up-strokes before the opening of the admission valves. Each pump piston-rod f carries a fixed piston f and a sliding spring-controlled piston f<4> the cap f<6> providing for the adjustment of the spring pressure and therefore of the delivery pressure. Superposed pumps of similar construction and driven by a single rod are used to supply both liquid fuel and compressed explosive mixture or gas for use in the vaporizer. The driving-gear for the superposed pumps is shown in Fig. 8. Valves and valve-gear ; governing.-The cylinder inlet valves c<1>, c<11> have flat faces to cover the airinlet ports c<5> and conical extensions to control the gas or explosive mixture ports, and are held closed at the proper time by cam-operated levers c<8>, c<81>, which engage the valve stems between the collars shown in Fig. 7, and the controlling-springs c<3>, c<31>. The valves are opened, after the closing of the exhaust valves, by the pressure of the incoming charge, the controlling-springs being depressed by the pivoted levers c<8>, c<81>. The exhaust valves el, ell are mounted on rods e<2>, e<21> having yielding connexions e<4>, e<41> respectively, motion being communicated to the valve-rods through pivoted levers e<5>, e<51>, Fig. 4, and cams k<2>, k<21> carried by an outer sleeve on an adjustable shaft k. Projections e<3>, e<31> on the exhaust valves keep the inlet valves to their seats until the former valves have closed. The speed of the engine may be governed, automatically or otherwise, by adjusting the cams k<2>, k<21> to vary the time of closing of the exhaust valves and thus the opening of the inlet valves. Carburetting. - Liquid fuel is sprayed into an exhaust-heated and internally-ribbed vaporizer H at h<1>, and the jet is broken up by explosive mixture or gas injected at h<4>. Both the explosive mixture or gas and the oil supply are heated before admission, any unvaporized fuel being retained in a trap h<7>. Any excess of pressure is relieved through a safety-valve inserted at h<8>. The explosive mixture or gas used for breaking up the fuel jet is stored in a reservoir, which is charged by a pump drawing its supply from the vaporizer. Cylinders, cooling.-Communicating water jackets are provided on the high-pressure cylinders and the air-pump a<2>, as shown in Fig. 6, depending tubes on each of the power cylinders being used to circulate the cooling-water in the hollow interiors of the pistons. Reversing; stopping.-At starting, compressed air is admitted from the chambers I, P to the inlet valves, and compressed explosive mixture to the vaporizer as in normal working. To reduce the speed before reversing, compressed air from the reservoir I is admitted to the underside of the low - pressure piston during each down - stroke through a valve (not shown), which is actuated by a cam m<10> on the reversing-shaft, Fig. 7. The reversing - shaft comprises an outer sleeve k<1>, rotated by means (not shown), and an inner longitudinally adjustable shaft k carrying pins which work in inclined slots in the actuating-cams. The outer sleeve has no endlong motion, an angular adjustment only being given to the cams. The cam m<10> readjusts itself after reversal to enable the valve lever m<9> to work on the concentric portion of the cam, and thus keep the valve in the front end of the low - pressure cylinder closed during normal working. This is effected by forming the cam with an extension on which is a lug m<15> engaging with a corresponding lug m<14> on a collar fixed to the inner shaft k. The cam slides on the outer sleeve and is slotted to receive a pin therein.