GB570586A - Improvements in or relating to internal combustion engines of the free piston type - Google Patents

Abstract

570,586. Free-piston engines. SULZER FRERES SOC. ANON. May 27, 1943, No. 8476. Convention date, May 28, 1942. [Classes 7 (i) and 7 (ii)] An internal-combustion engine of the freepiston type having two pipes 14, 15 directing scavenging air from compressor cylinders 2, 3 to opposed points on the working cylinder adjacent the scavenge ports 16 has means such as non- return valves 21. to prevent flow from one supply pipe to the other. The cylinders 2, 3 have suction and delivery valves 10, 11 respectively and compressed air is delivered to collecting chambers 12, 13 and thence to the pipes 14, 15. Exhaust gases pass from ports 18 to a container 20. To prevent oscillation of the air column in the pipes 14, 15, the volume of each collecting chamber may be a multiple of the volume swept by the working cylinder pistons 6, 7. Also the cross-section of pipes 14, 15 is preferably equal to or less than that of the cylinder 1. In a modification to prevent flow between the pipes 14, 15, the space 22 around the inlet ports is subdivided by a partition wall. In another modification, Fig. 4, the scavenging air pipes 14, 15 are connected directly to the compressor cylinders and non- return valves 28 are arranged at the junction of these pipes with an inlet pipe 27. Throttling nozzles 29 may be arranged in the pipes 14, 15 to damp oscillations and prevent back flow into the pipes.