Patent ID: 7004121

Claim:
An arrangement for a piston engine, the arrangement comprising: an angularly rotatable cam having a camming surface, the camming surface being definable by a graph in which the abscissa represents a rotational angle for the cam between 0° and 360° and the ordinate represents the distance of the cam surface from a reference, said cam surface having a first sector occupying a portion extending along the abscissa and a second sector occupying a portion extending along the abscissa, said first sector having positive slopes with respect to said reference, said positive slopes including an intermediate portion of a constant slope, said second sector having negative slopes with respect to said reference, said negative slopes including an intermediate portion of constant slope; and a plurality of cylinder-pistons equally spaced around a periphery of said cam and engaging the cam, the number of pistons and the positive slopes arranged such that when the cam surface is rotated at a constant speed, the sum of the linear speeds of all pistons following the positive slopes of the first sector is constant.