Abstract: A linear motion mechanism in which a series of pivotally connected links are connected between a support and a controlled member such that as one of the links is swung in a 360.degree. arc, the controlled member alternately moves in a first direction along a linear path of motion and then in the opposite direction along a curved path of motion.In another embodiment of the invention, the weight of the controlled member is balanced by a counter weight connected to the linkage to provide a lifting mechanism.Another embodiment employs a cam to produce a motion in which the controlled member moves in a horizontal path with a short vertical motion at each end of the horizontal motion.