Patent GB-757951-A (GB)
Title: Means for starting free-piston internal-combustion engines
IPC: F02C5/08
Filed: 1954-06-28
Abstract: 757,951. Starting; free-piston engines. PETERSON, H. June 28, 1954 [June 27, 1953; July 18, 1953], No. 18938/54. Classes 7(2) and 7(5) Two phase starting. In means for starting a free-piston engine wherein a container for a pre-determined volume of starting gas at a given pressure is connected to the starting chambers 96, Fig. 1, of two opposed free-pistons, only one of which is shown at 91, in such a way that when the pistons are in the starting position they mask the outlets 93 of the connections from the container into the chambers 96, and wherein restricted passages 97 are arranged between the connections and one side of each piston 91, a control device is provided which when operated permits the container to supply gas to the passages 97 so as to move the pistons in a first starting phase towards positions where they unmask the outlets 93 to enable a second starting phase to begin in which the pistons continue to perform their full starting stroke due to a delivery of gas freely through the outlets. The expanded gas escapes to atmosphere or a scavenging air-receiver via a piston-controlled port 98. The bore 97 may be formed in a plug and the cross section of the bore may be altered by using different plugs. Starting operation. The engine and single-stage compressor free-pistons 1, 2 Figs. 3, and 3, 4 respectively, are brought to the positions shown by a removable handle 50 on one of the two rocking levers 8; gas from a cylinder 39 is then admitted to a container 43 by way of a reducing valve 42. A starting valve 44 is opened to admit the gas from the container 43 into a conduit 36 which opens into the buffer and starting chambers 30 and 31 of the compressor via valves 34 and 35 to initiate the two-phase starting as described above, fuel being injected by the nozzle 17 when the pistons 1 and 2 approach each other. The cylinder 39 is charged with air or gas from a cylinder space 14 by way of valves 48 and 40 and the engine is scavened by air from the space 24 enclosed by the engine, compressor and end plates 25, 26, which space is in communication with the engine pump chambers 18, 19 and the compressor chambers 30, 31. In a modification, an air venting valve 55, Fig. 4, is opened which through a conduit 52 places both the chambers 58, 59 of a two-stage compressor in communication with atmosphere; a valve 85 is actuated to admit gas from the cylinder 84 into valve 82 and 60 and 61 via a reducing valve 82 and conduits 80 and 81. From chambers 60 and 61 the gas passes valves 64 and 65 and flows through conduits 66 and 67 into a container 68 which is connected to ports 71 and 72, respectively, in the compressor cylinder; small quantities of gas penetrates behind the compressor pistons in the spaces 30a and 31a by the way of ports 32 and 33 and 71 and 72 and the clearances between the pistons and cylinders, which gas is vented to atmosphere through the conduit 52. The engine cylinder space 14 is supplied with fuel and the valve 55 is closed so the first starting phase is effected by the gases which have leaked through the piston and cylinder clearances, the second phase commencing when the ports 32 and 33 are uncovered. Engine chambers such as 18, 19, may also be used for starting purposes. The starting pistons may each be formed with a restricted bore so that when in the starting position starting gas can pass into the space 24. Specification 605,009 is referred to.