Cam actuation mechanism with application to a variable-compression internal-combustion engine

A cam actuation mechanism comprising in combination:

• (a) at least one pair of preferably identical cams, comprising a first and a second cam, each cam comprising a curvilinear slot, said curvilinear slot being bounded by an inner surface, defined by an inner variable-radius curve, and by an outer surface, substantially parallel to said inner surface and defined by an outer variable-radius curve, each variable-radius curve being rotationally symmetric, whereby the absolute rate of change in radius length, over an arbitrary curve angle, is the same, irrespective of the origin and direction of said arbitrary curve angle,
• (b) coupling means, including a shaft, for providing a torsionally rigid joint between the two cams of a pair, wherein the cams are coaxially mounted to said coupling means,
• (c) a driven member, capable of moving linearly along an axis substantially perpendicular to the axis of rotation of the cams,
• (d) at least one pair of substantially cylindrical slot followers, rigidly attached to said driven member, comprising a first and a second slot follower, whereby said first slot follower is captively engaged into said curvilinear slot of the first cam and said second slot follower is captively engaged into said curvilinear slot of the second cam, and
• (e) actuator means for simultaneously rotating the two cams of a pair to a predetermined angular position, thereby urging said driven member to a linear position, determined by the geometrical profile of the variable-radius curves defining the curvilinear slots.