Patent GB-603195-A (GB)
Title: Improvements in two-stroke, free-piston internal combustion engines
IPC: H02K7/18
Filed: 1945-11-13
Abstract: 603,195. Gas turbines; centrifugal governors. MILLER, G. B. Nov. 13, 1945, Nos. 30378/45 and 739/46. [Classes 57 and 110 (iii)] [Also in Groups XXVII and XXXV] A two-stroke free piston internal-combustion engine, Figs. 1a, 1b and 2 having a plurality of cylinder units 2, with a common combustion chamber formed in the head 3, arranged in the corners of a regular polygon with an even number of sides,' four as shown, and having twin pistons 39, 40 joined by piston rods 41 and working in opposed coaxial cylinders has a means for constraining the pistons so that those pistons in one cylinder unit work in phase with one another and are 180 degrees out of phase with the pistons in the adjacent cylinder units on each side. Air inlet ports 4 are arranged in one cylinder of the unit and high pressure and low pressure exhaust ports 6 and 5 respectively in the other cylinder. The ports 6 are opened by the piston valve 10 on the expansion stroke but are closed on the compression stroke by rods 13. Fuel from a tank is sucked to the fuel pump 19 through the pipe 18 and then fed under pressure to the spring loaded accumulator 21 from whence through pipes 22 it is fed to injectors 23 which are mechanically operated by pull rods 38. The racks 42 on the piston rods 41 engage pinions 43 attached to the armatures of alternators 44 which are connected in parallel so that no mechanical synchronization of the piston rods will be necessary owing to the automatic tendency of any alternator which gets slightly out of phase to be pulled back into synchronism with the others (see Group XXXV). The permanent polepieces of the magnet 44<11> are energized by a D.C. generator 111 driven through the reduction gear 54 by an exhaust gas turbine 8 also driving a supercharge pump 9. The said generator 111 may be used as a motor for driving the supercharger 9 during the starting operation. The fuel injector operating rods 38 are,energized from the cam gear box 14, Fig. 3, by a cam 11 driven by a synchronous motor 47, Fig. 2, obtaining its current from the alternators 44. The levers 74, 75 pivoted at the points 76, 77 have rollers 72, 73 bearing on the cam 11 supplied with a diametrically opposed rise and depression 70 and 71. A clockwise rotation only of the lever 74 operates the rods 86, 88 through the lever 82 and an anticlockwise rotation only of the lever 75 operates the rods 85, 87 through the lever 83 hence the amount of opening of the fuel injector depends to what depth the rollers 72, 73 sink into the cam depression 71, which is in turn proportional to the width of the member 68 which is of tapered form 'and is vertically positioned by the engine speed control governor 63, Fig. 2, driven from the cam shaft 12 by the chain and sprockets 65, 64, 66. The governor 63 is connected through a spring 93 and rod 69 to wedge 68 which is oil damped at its lower end. Beneath the cam gear base 14 and sprocket 64 is a further box containing a series of cams connected to the camshaft 12 for operating the rods 13 and hence the exhaust valves 6. The pipes 7 lead the high pressure; exhaust gases to the turbine 8 which has a speed control governor 49 and a casing temperature regulator comprising a bimetallic strip 48. If either of the valves 50, 52 are opened in the member 57, Fig. 5, air is admitted to the chamber 59 and so to the turbine jets 61 through pipes 60 hence cooling said gases and decreasing the speed and efficiency of the turbine. The governor 49, Fig. 2, is connected to the valve 52 and the bimetallic strip 48 on the turbine casing 8 is connected to valve 50.