Abstract: A lock, which releasably affixes to the end of a cylindrical rod, includes a torus-like case having a central cylindrical passageway that fits over the rod. A spring normally urges a pair of cylindrical pistons located in the case to a locked position where they partially extend into the passageway by a spring. An actuation mechanism allows the pistons to be moved to an unlocked position where they are completely contained within the case by pressing a plunger that extends through the case. The rod contains a plurality of pairs of openings at specified locations along the rod that receive the pistons when the lock is placed on the rod.

Abstract: A rotary exercise apparatus includes a frame which supports a seat assembly and a rotary crank mechanism. The frame has two sets of legs, one which supports the apparatus in an upright position where the crank mechanism can be used by someone sitting on the seat assembly to perform upper body exercises, and another which supports the apparatus in a reclined position where the crank mechanism can be used by someone sitting on the seat assembly to perform lower body exercises. The crank mechanism permits variable amounts of resistance to be imparted against its rotation by urging a shoe having a high friction liner against a rotatably mounted shaft that carries the crank arms. The location of the crank mechanism along the frame and the length of the arms are adjustable to accommodate different size users. In addition, the arms are replaceable to permit different size and shape arms carrying appropriate engagement devices to be used for each type of exercise.