Abstract: A concentric threaded fastener comprising a body with a starting shape, an ending shape, and at least one continuous surface formed by layers between the starting shape and the ending shape, where the layers are concentric so that each successive layer from the starting shape to the ending shape has local clearance between the layer and a larger adjacent layer and so that each layer forms a plug when it is aligned in an unrotated position, and where each layer is successively rotated about at least one axis to form the continuous surface. A concentric threaded system comprising a concentric threaded fastener and a receiving component comprising an opening with mating continuous surface dimensioned to accept the continuous surface of the concentric threaded fastener so that the mating continuous surface and the continuous surface of the concentric threaded fastener make complete surface contact when the concentric threaded fastener is at a terminal position within the receiving component.

Abstract: A concentric threaded fastener comprising a body with a starting shape, an ending shape, and at least one continuous surface formed by layers between the starting shape and the ending shape, where the layers are concentric so that each successive layer from the starting shape to the ending shape has local clearance between the layer and a larger adjacent layer and so that each layer forms a plug when it is aligned in an unrotated position, and where each layer is successively rotated about at least one axis to form the continuous surface. A concentric threaded system comprising a concentric threaded fastener and a receiving component comprising an opening with mating continuous surface dimensioned to accept the continuous surface of the concentric threaded fastener so that the mating continuous surface and the continuous surface of the concentric threaded fastener make complete surface contact when the concentric threaded fastener is at a terminal position within the receiving component.

Abstract: A conic threaded fastener and conic threaded fastener system. The conic threaded fastener includes a body having at least one substantially conic outer surface and at least one conic thread forming a spiral about the substantially conic outer surface of the body. The conic thread forms a plurality of crests and a plurality of roots and the tangential distance between adjacent crests is substantially constant. The conic threaded fastener system includes the conic threaded fastener and a workpiece with an opening having at least one inner conic surface dimensioned to mate with a conic outer surface of the conic threaded fastener.

Abstract: A transmission that functions as a combination friction drive and gear tooth drive: The transmission utilizes VCT conic teeth added to the surface of a variable pulley. The teeth in the sides of a continuous loop, or a two-faced gear, engage the teeth on this conic surface. When the pulleys contract or expand, the top of the teeth engage the surface frictionally. When the contraction or expansion of the pulleys move the continuous loop, or two-faced gear, to the next ring of conic teeth, it engages the conic teeth as a toothed drive.