Patent ID: 7909013

Claim:
An internal combustion engine, comprising: a housing having an interior region with a generally circular cross section defined by an inner surface of the housing, wherein the generally circular cross section is interrupted by a rocker mounting region, the housing also having a pair of sides; a cam, rotatably mounted in the housing, that sweeps a circular path in the interior region, the cam in sealing contact with the sides of the housing and also, when a leading edge of the cam is not adjacent to the rocker mounting region, in sealing contact with the inner surface of the housing; a cam-following rocker, mounted in the rocker mounting region, in sealing contact with the sides of the housing, and, at least when the leading edge of the cam is not adjacent to the rocker mounting region, in sealing contact with the cam, the rocker having a seated position defining generally, when a leading edge of the cam is adjacent to the rocker mounting region, a continuation of the circular cross section of the housing, the rocker pivoted at a pivot end to move at a free end generally radially with respect to the circular path of the cam, so that the free end of the pivot reciprocates between the seated position and a maximum unseated position, completing a full reciprocation cycle when the cam completes a revolution around the working region; a combustion chamber, defined at least in part by the cam and the housing, and formed in the housing proximate to the rocker mounting region adjacent to the free end of the rocker, and having an opening, such opening being occluded by the cam over a first angular range of rotation of the cam; an intake port coupled to the combustion chamber for providing pressurized working medium, the working medium including one of (i) an oxygen-containing gas to which fuel is added within or before the first angular range and (ii) an oxygen-containing-gas-fuel mixture; wherein combustion occurs within the first angular range so as to provide substantially constant volume combustion in the combustion chamber; the cam and the rocker being configured to provide an expansion region over a second angular range when the arcuate opening is not occluded; and an exhaust port, formed in the housing proximate to the rocker mounting region adjacent to the free end of the rocker, for removing expended working medium; wherein the cam provides an output torque relative to the housing resulting from the combustion.