Abstract: A multi-stage air throttle valve assembly is provided for use in a multiple cylinder engine. The valve assembly provides a series of shiftable valve plates to provide full, maximum opening of air ports having passageways therethrough for introduction of air into the combustion cylinders of the engine. By use of two or more such sliding plates, the port size through the assembly may be maximized for enhanced volumetric entry of air into the combustion chambers. A combined reed valve assembly, fuel injectors and/or an air velocity assembly with engine are also disclosed.

Abstract: An apparatus and method are provided for enhancing fatigue and load properties of subterranean well drill pipe immediate the area of securement of pipe sections by providing a weld in a discontinuous plane to secure pipe sections to each other, said weld having a greater cross section of welded surface and ability to distribute stresses which is less prone to fail due to rotational, tensile, and bending stresses, mid due to heavy loads and stresses arising from shock loading.

Abstract: An apparatus and method are provided for enhancing fatigue and stress resistance properties of a subterranean well drill pipe string section by providing a helical groove near the pipe to tool joint weld. Stresses in and around the top portion of the pipe are redistributed to and absorbed by the helical groove region of the drill pipe string section, which has a relatively greater resistance to fatigue caused by bending and other stresses, thereby making the drill pipe string section less prone to fail due to rotational, tensile, and bending stresses.