Patent GB-563372-A (GB)
Title: Improvements in internal combustion engines
IPC: F02M21/12
Filed: 1943-03-24
Abstract: 563,372. Compression-ignition internal-combustion engines. CASTELLINI, A. P., and ROBEY & CO., Ltd. March 24, 1943, No. 4801. [Classes 7 (ii), 7 (iii) and 7 (vi)] A compression-ignition internal-combustion engine for using powdered fuel has a positive feed device for feeding fuel to a measuring drum, whence measured charges pass first to an aerating turbine associated with an adjustable air valve and then through a preheating chamber to the working cylinder. In the application to a single-cylinder 4-stroke engine of Diesel type, the cylinder 1, Fig. 1, has a head 2 which is preferably detachable so that existing engines may be modified. The head is provided with an air valve 3 operated by a rocker 9 and an exhaust-valve 4 operated by a rocker 10. The valves operate in detachable guides 11 bolted to the head at 12 and have adjustable stems 8. The main piston 14 which is recessed to clear the valve heads has a cavity in its head which accommodates a small cylinder 26 secured in position by bolts 27. This cylinder has a piston whose head is fitted with a non-return valve 45, the piston being operated during the reciprocation of the main piston by means of a toothed segment on the small end 40 engaging a segment on a lever arm 35 pivoted at 33 to the connecting-rod 30. The upper part of the auxiliary cylinder has a valve 48 leading via chamber 16 and radial passages to a peripheral groove 17, Fig. 6. Normally, a spring ring 19 engages valves 20 to close the radial passages, but pressure of air in the passages opens the valves and expands the ring, thus allowing air to escape along passages 18 and clearing dust, ash, &c. from the walls of the working cylinder. Air from the crank-case enters the secondary cylinder through valve 45 and is forced past valve 48 to the radial passages on upward movement of the secondary piston. The fuel feed hopper 55, Fig. 7, for powdered carbonaceous fuel such as anthracite with a small proportion of bituminous or volatile fuel, carries a reciprocating rod 56 provided with fins 57 and actuated through an arm 58 from a cam-wheel 60 operated intermittently through pawl-and-ratchet mechanism from a camactuated tappet 67. The shaft 62 of the camwheel carries a recessed feed-drum 63 receiving measured amounts of fuel from the hopper. The feed-drum communicates through a regulating-shutter 86 with the inlet 74 of a turbine rotor having blades 76 which aerate the fuel particles. The turbine is driven from the halfspeed cam-shaft 70 through bevel gearing 82, 81 and free-wheel device. A starting shaft 84 is also geared to the turbine shaft and may be driven from a starting motor energized from an electrical source for' starting the engine on solid fuel. The front cover of the turbine casing is perforated at 90 and coacts with a perforated adjusting ring 90a to vary the air supply to the turbine. The walls of the hopper may be jacketed and heated by exhaust gas to keep the fuel dry. A port 92 leading from the turbine is controlled by a valve which is operated by lever mechanism from a cam 98a to admit fuel to a chamber 94, Fig. 4. From this chamber a spring-loaded valve 100 opened by a lever 109 actuated by a cam 119 allows fuel to pass to the working cylinder. A conical shoulder on the valve stem coacts with a seating 106 in the guide. One of the tappets in the actuating-train of valve 100 may be lengthened and shortened by the coaction of helical surfaces on its component parts so that the valve 100 may be put out of action if liquid fuel is to be used. The change-over is effected by a lever 88 which is also connected to the mechanism for imparting movement to the feeddrum so that the solid fuel feed is put out of action and the valve 100 locked against opening when change-over is effected. At the same time a tappet 135 is engaged with a cam 137 to bring into action a pump 138 supplying through conduit 139 an injector nozzle 140, Fig. 4. Another valve 172 in the chamber 94 allows inflow of air during the exhaust period of the working cylinder. For governing the engine speed, a governor of the centrifugal type is driven by gearing 126 and actuates a lever 130 connected to the shutter 86. The lever 130 also controls liquid fuel supply through a rack 141. A water-pump 150 may be operated by a cam 153 to supply water to an injection nozzle. The engine may be started by compressed air supplied to a valve operated through lever mechanism from a cam 163 on the camshaft 70. This compressed air is admitted on the explosion stroke only and the tappet 161 is rendered inoperative as soon as the engine starts. To reduce the starting effort a decompressor lever is rocked by a cam 168 so that it engages a roller on the exhaust valve rocker and opens the exhaust valve for part of the compression stroke. Ignition of the charge begins to occur in the chamber 94. At about 5 degrees before the beginning of the power stroke the valve 100 is opened admitting this partly ignited mixture into the compressed air charge in the cylinder where complete ignition occurs. The valve 100 remains open till near the end of the suction stroke so that the chamber 94 is first exhausted and then supplied with fresh air through the valve 172. Water may be injected by pump 150 after the beginning of the power stroke. When solid fuel is being used, the injector 140 is replaced by a plug'177 which closes the port 178. In a modification, the chamber 176 is dispensed with and the chamber 94 fitted with alternative devices for the use of solid or liquid fuel.