Eccentric crank with continuously adjustable throw

An eccentric wherein the amplitude of reciprocation is continuously adjustable during operation comprising:

• a sleeve, having a first end, a second end, and an axis of rotation, rotatably mounted on a frame;
• a shaft slidable inside said sleeve, said shaft having a projecting end projecting from said second end of said sleeve, said shaft freely movable along said sleeve from a withdrawn position to a projected position, where said projecting end is nearer said sleeve in said withdrawn position than in said projected position;
• hinge point support means fixedly attached to said sleeve and supporting a first hinge point removed from said axis of said sleeve;
• a throw arm with a hinge end and a pivot end, said hinge end hingably attached at said first hinge point such that said arm may move freely in a plane defined by said first hinge point and said axis of the sleeve;
• a pivot attachment point located at said pivot end of said throw arm;
• a linkage member having a shaft end and an arm end, said shaft end hingably attached to a shaft hinge point on said shaft near said projecting end thereof and said arm end hingably attached to an arm hinge point at a mid-point of said throw arm, such that said pivot attachment point is located at a first point on said plane when said shaft is in said withdrawn position and moves away from said axis along said plane when said shaft is moved towards said projected position;
• and
• means to move said shaft from said withdrawn position to said projected position while said shaft is rotating.