Patent ID: 7174864

Claim:
A combustion engine comprising, a pair of opposed cylinder elements having a common axis, each cylinder element being provided with a piston reciprocable between first and second locations in the cylinder element the first and second locations respectively representing compression and expansion elements of the piston stroke, each piston having a forward side and a rear side, a combustion chamber for each cylinder element comprising the forward side of the piston and the walls of the cylinder element, combustible gas compression means for each combustion chamber, supply passage means arranged to deliver combustible gas to each combustion gas compression means, an induction chamber for each piston arranged to receive compressed combustible gas from the combustible gas compression means, transfer passage means for directing compressed gas from each induction chamber to the respective combustion chamber, cam means rotatable about the common axis the cam means being located between the pistons and being connected to each of the pistons for converting the reciprocating motion of the pistons into rotary motion of the cam means, the cam means comprising a cam track encircling a drive shaft aligned with the common axis, and cam follower means connected to the pistons the cam follower means being arranged to follow the cam track whereby to convert the reciprocating motion of the pistons into rotary motion of the drive shaft, wherein the arrangement is such that expansion stroke movement of each piston results in a corresponding compression stroke for the compression means and the pistons are coupled so that an expansion stroke of one of the pistons drives the compression stroke of the other of the pistons.