Abstract: A novel drive mechanism for a bicycle, featuring a scissor assembly defined by plurality of arms pivotally interconnected in an expandable sequence. The scissor assembly is attached pivotally to a frame on both sides and via a rigid slot attached pivotally to pedal cranks whereby permitting cranks oscillating motion. The cranks reciprocal oscillating motion is transferred by the assembly into a linear pulling force connected to a drive wheel axle, equipped with a freewheeling reel, by a flexible ligament spiraled in the reel. The efficiency of assembly's power transfer kinetics lessens required human force, in addition, the speed is substantially increased because the cranks motion is confined to the most efficient frontal segment of the 360-degree orbit whereby eliminating back-upward segment of the circular motion pedals.

Abstract: A beach sling-jump amusement device for ejecting occupants into the air, featuring a pair of bows intersected by a brace secured on a support frame. An ejection seat having portions defining a trampoline for receiving an occupant. The trampoline is supported centrally in place by drawstrings laced to the bow arching arms. Unlike a conventional bow, the drawstrings with the seat are retracted to a drawn position in opposite direction toward the bow arch, enabling unobstructed ejection of an occupant into a free-flight and safe landing in water. The seat is retracted into a ready position by a winch mounted on the frame. An optional projectile capsule is provided, which is essentially a hollow ball made from a resilient material having a receiving cavity for an occupant. The capsule, adapted and sized for accommodating an occupant, is loosely positioned on the trampoline ring.