Patent GB-666507-A (GB)
Title: Improvements in or relating to two-stroke internal combustion engines and method of operating the same
IPC: F02M69/00
Filed: 1949-02-16
Abstract: 666,507. Cycles; cylinders; valves. TEXACO DEVELOPMENT CORPORATION. Feb. 16, 1949 [Feb. 27, 1948], No. 4235/49. Classes 7(ii), 7(iii) and 7(vi) In a two-stroke internal - combustion engine comprising an exhaust valve 17, Fig. 1, situated at one end of a cylinder 12, inlet ports 20 at the other end thereof, the ports 20 being arranged to impart a high-velocity swirling motion to the incoming air, a fuel nozzle 26, and a sparking plug 30, the air being compressed in a combustion space 25, which latter is generally circular in transverse crosssection, and the fuel sprayed into a segment of swirling air on one side of the space 25 and after ignition establishing a flame front travelling counter to the direction of air swirl, it is arranged that the exhaust and air admission are both initiated during the latter part of the power stroke, the inlet ports 20 opening after the exhaust valve 17,  fSO  that the swirling air advances in a column to effect uninow scavenging the exhaust terminating and the air admission continuing during the initial part of the compression stroke, and the timing of fuel injection and ignition being co-ordinated together with the rate and duration of injection, in order to provide Otto cycle operation with a maximum pressure rise close to the inner dead-centre position of the piston. The exhaust valves are tappet operated and the inlet ports 20 are piston controlled whilst the air may be supercharged and the fuel nozzle 26 arranged to spray tangentially into the cylinder in the direction of the air swirl caused by the tangential entry of the air through the intake ports 20. The sparking plug 30 is located in the combustion space 25 so that its electrodes are situated between 20-90 degrees preferably 30-45 degrees, from the point of fuel injection, the ignition being initiated in a small area opposite the plug and being propagated by the swirling air. In a modification, an opposed piston engine is described in which one piston controls the inlet port and the other the exhaust port, the latter leading the other pistons by about 10-20 degrees of crank angle to provide for the correct relationship between the opening and closing of the inlet and exhaust ports. In a further modification. the exhaust ports are piston controlled and two inlet ports are provided each with a tappet operated valve, each valve having an oppositely facing shroud to swirl the incoming air, the shrouds extending half way around the valves. If only one central inlet port is used its valve is equipped with curved varies. In anothermodification, the -cylinder 90, Fig. 8, embodies a ring of inlet and exhaust ports 96 and 93, respectively, the inlet ports being triangular and arranged to promote swirling of the air. Within cylinder 90 is a sleeve valve 99 with inlet and exhaust ports 101 and 100, respectively, the valve being driven by the engine to perform a reciprocati n g as well as a rotatary motion. An axially positioned fuel .nozzle 115 gives radial injection from two jets 116 each jet having a sparking plug associated therewith the angle between the nozzle and sparking plug electrodes being between 30-45 'degrees; the piston may control the opening of the exhaust ports and sleeve valve the closing thereof. The conventional sparking plugs, which could be connected in order to operate continuously, may be replaced by incandescent igniters. The engine compression ratio lies within the range of 4-10:1, whilst crank angles for the opening and closing of the ports as well as the commencement and cessation of fuel injection and ignition are given. The engine may operate on gaseous fuel, such as butane, which is transformed into a liquid state prior to injection into the engine. Specification 596,846 is referred to.