Patent GB-190823359-A (GB)
Title: Improvements in Two Stroke Cycle Internal Combustion Engines.
Inventor: HOLLICK THOMAS DRAKE
Filed: 1908-11-02
Granted: 1910-02-02
Abstract: 23,359. Hollick, T. D. Nov. 2. Gas or explosive - vapour engines.-To obtain high-compression pressures with comparatively low working temperatures, two-stroke-cycle engines are arranged to retain at each exhaust period a portion of the combustion products through which the explosion pressure is transmitted to the piston. In the engine shown in Fig. 1, inlet and exhaust valves. 5, 6 are arranged in a combustion chamber 4 separated from the cylinder by a contracted neck 3. The combustion chamber may, however, be arranged vertically in which case a single cylindrical slide valve controls the distribution. At the end of each out-stroke, the opening of the exhaust valve 6 by a projection 17 on the cross-head 18 is followed, upon a suitable reduction in the cylinder pressure, by the entry of explosive mixture through the valve 5 ; this mixture, preceded by an air charge, expels the products of combustion in the chamber 4 immediately before the closing of the exhaust valve. During compression, the charge remains stratified, the trapped inert gases being in contact with the piston and serving to transmit the pressure of the gases resulting from the explosion in the end of the combustion chamber remote from the exhaust valve. The air used for the formation of the mixture is compressed in the front end of the cylinder, being stored in a reservoir 7 in which, and in the inlet pipe or pipes 11, the charge is cooled. Liquid fuel is supplied from a reservoir 12, connected to the air reservoir 7 by a pipe 15 through a nozzle 14, the outlet from which is controlled by a spring-pressed valve 21 carried by the stem of the admission valve 5. The opening of the air valve before the fuel orifice ensures the admission of an air charge before the explosive mixture. If preferred, the fuel may be sprayed directly into the combustion chamber, as described in Specification No. 13,953, A.D. 1906. Governing.-A throttle valve 10 controlled by hand or governor, or by both, regulates the discharge of the combustion products; and also deter mines indirectly the quantity of mixture admitted through the inlet valve 5. If the throttle valve is dispensed with, the exhaust valve 6 is given a variable lift. When used on a road vehicle, the motor may, when running light or descending hills, compress air above the normal pressure ; this air may be used to augment the power in inserting an overload. To regulate the pump discharge, the inlet valve 19 may be controlled by hand or governor, or by both. If the pressure of the air delivered by the pump is insufficient to meet the normal load, an additional pump may be used. In a modified compound engine, the exhaust valve of the low-pressure cylinder is controlled similarly to effect the same object as the valve 10. Compound engines.-A compound engine is described in which the low-pressure piston is connected to the cross-head pin of the high-pressure piston through a rocking-lever which also actuates the outlet valve of the high-pressure cylinder. The engine may be modified to work with (1) one or more double-acting high-pressure cylinders discharging into one or more double-acting lowpressure cylinders and having independent pumps ; (2) two single-acting high-pressure cylinders discharging into one double - acting low - pressure cylinder; (3) one single - acting high - pressure cylinder discharging into a single-acting lowpressure cylinder with an air-pump thereunder ; and (4) one single-acting high-pressure cylinder, the front end of which forms the low-pressure chamber, and an air-pump arranged in tandem.