Abstract: The double action piston assembly is for an internal combustion engine and has a combustion chamber that has a double action piston connected to one end of a central power rod disposed within the combustion chamber. A first intake air port and a first exhaust port are located in the up side of the combustion chamber. A compression chamber is connected to the combustion chamber. A central power rod passes through the combustion chamber into the compression chamber and out the compression chamber. A fuel mixture is fed into the combustion chamber and ignition means adjacent to combustion chamber to ignite the fuel mixture. At the end of each stroke, the compression exhaust valves are opened and the intake ports and the exhaust ports are open to permit air from the compression chamber to pass through the conduits into the combustion chamber for full scavenging of the combustion chamber.

Abstract: The double action piston assembly is for an internal combustion engine and has a combustion chamber that has a double action piston connected to one end of a central power rod disposed within the combustion chamber. A first intake air port and a first exhaust port are located in the up side of the combustion chamber. A compression chamber is connected to the combustion chamber. A central power rod passes through the combustion chamber into the compression chamber and out the compression chamber. A fuel mixture is fed into the combustion chamber and ignition means adjacent to combustion chamber to ignite the fuel mixture. At the end of each stroke, the compression exhaust valves are opened and the intake ports and the exhaust ports are open to permit air from the compression chamber to pass through the conduits into the combustion chamber for full scavenging of the combustion chamber.

Abstract: Soil/metal supporting structures commonly include panel sections having a short radius of curvature in the range of 750 mm to 2,500 mm. In such soil metal supporting structures the panels are of heavy gauge in the range of 2 mm to 10 mm thickness. Usually, expensive tooling and forming techniques are required to cold form the heavy gauge material into a curved shaped having such short radius. Such expensive techniques have been eliminated by this invention by virtue of the improvements comprising:a) the panels have a high degree of ductility before being cold formed, such high degree of ductility being determined by a ratio of specified minimum yield strength to specified minimum tensile strength equal to or less than 0.