Abstract: A wheeled vehicle propelled by a rider comprises a frame, front and rear wheels rotatably mounted on the frame; and a tiller tube, provided with handle bars and foot pedals which may be used separately or together for providing oscillatory movement thereof about a pivotal axis of the tiller tube. The vehicle further includes cable drive means and at least one unidirectional clutch which when driven turns one or more wheels, preferably the rear wheels. The ends of the cable are rotatably anchored to a sheave mounted on the tiller tube, and means are provided for moving the sheave up and down the tube in infinitely variable increments for changing from a high-speed to a low-speed position and vice-versa so as to provide suitable speed changing. Means are also provided on said vehicle for braking and steering.

Abstract: For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil.