Patent ID: 7162935

Claim:
A crankshaft coupling structure used in an engine and coupled between a piston and a crankshaft to enhance the output torque of the engine, comprising: a connector pivotally connected to said crankshaft, said connector having a radially extended sliding slot spaced laterally from said pivotal connection to said crankshaft; a coupling rod member, said coupling rod member having a top end pivotally connected to said piston; and a coupling member fastened pivotally to a bottom end of said coupling rod member and received in said sliding slot, said coupling member being reciprocatingly movable with said coupling rod member between two distal ends of said sliding slot for varying an eccentricity of said coupling of said coupling rod member to said crankshaft, said coupling member being displaced to a first of said two distal ends having a minimum eccentricity during an up stroke of said piston and displaced to a second of said two distal ends having a maximum eccentricity during a down stroke of said piston to thereby increase the output torque of said engine.