Abstract: A method of forming a tubular frame, e.g., a bicycle frame, from two substantially symmetrical frame-halves utilizes a plurality of interconnected half-tubular elements. Each half-tubular element has an exterior surface, an interior surface, and longitudinal edges that extend between the exterior and interior surfaces in the direction of the longitudinal axis of the half-tubular element. The surfaces of the longitudinal edges of the half-tubular elements are shaped such that corresponding edges of corresponding half-tubular elements in the left and right half-frames may easily be interengaged, and adjusted along the respective longitudinal axes of the half-tubular elements that are being joined. Preferably, the longitudinal free edges are stepped in the radial direction such that each level is substantially planar and smooth along the respective longitudinal axis of the half-tubular element.

Abstract: A pressure vessel, or pressurizable canister is described herein. The canister has a hollow, thin-walled, cylindrical, metal shell. The preferred metal is aluminum, because light weight is a consideration for the vessel. Two end caps are mechanically sealed to the respective distal ends of the metal shell tube by the process of electromagnetic pulse forming. The two end caps are made of a high strength, ductile thermoplastic. The preferred plastic is DELRIN.RTM., which is fabricated from an acetal resin. The plastic end caps are injection molded, and can include reinforcing threads. The end caps are each cylindrically shaped, and have at least one circumferential recess to accommodate the metal of the shell tube as it deforms about the end caps. The tube shrinks into the recess of the end caps, and forms a mechanical seal therewith.

Abstract: A new method is disclosed of fabricating the joint between a golf club post and a drive shaft, as is the article fabricated therefrom. The golf club post to which the shaft attaches includes a circumferential recessed contour. The hollow, metal, electrically conductive golf club shaft is placed over the post, and an electric coil is placed around the shaft and post juncture. The electric coil is electrically pulsed, causing the shaft to shrink fit to the contour of the post. The electro-formed, mechanically bonded shaft is now permanently and integrally anchored to the golf club post. In a second embodiment, a non-conductive shaft of carbon fiber, for example, is electromagnetically bonded to the post, using a metallic ring, which is electromagnetically formed around the non-metallic shaft and post. In a third embodiment, the club head post is additionally fitted with at least one vertically disposed groove along the vertical axis of the post.

Abstract: A high speed transfer switch is provided for transferring a multiphase load among a number of multiphase A.C. power sources. If the initially selected source deviates from desired limits, the transfer switch transfers the load to an alternate source on a phase-by-phase basis. Antiparallel-connected SCRs are used to allow the load current in each phase to commutate to zero before the load is transferred to the alternate power source.