Patent ID: 7406930

Claim:
An internal combustion engine comprising: a cylinder structure defining a combustion cylinder having a central axis, a piston fitted slidingly in the combustion cylinder for reciprocation therein, a crankshaft assembly including a main crankshaft segment having a main axis, a crank web that is attached to the main crankshaft segment and projects from the main crankshaft segment, and a crank pin structure that is attached to the crank web and has a central axis that is parallel to said main axis and is spaced from said main axis by a distance D, the crankshaft assembly being journalled in the cylinder structure for rotation about said main axis, an elongate connecting rod extending substantially radially of the crank pin structure and having an outer end attached to the piston and also having an inner end, a first mechanism attaching the inner end of the connecting rod to the crank pin structure, whereby reciprocation of the piston induces rotation of the crankshaft structure about said main axis, and a second mechanism for selectively adjusting the distance D, and wherein the first mechanism permits substantially longitudinal movement of the connecting rod relative to the crank pin structure, and wherein the second mechanism is coupled to the first mechanism in a manner such that an increase in the distance D is associated with longitudinal movement of the connecting rod toward the central axis of the crank pin structure and a decrease in the distance D is associated with longitudinal movement of the connecting rod away from the central axis of the crank pin structure.