The mechanism contains a slider crank connected in parallel with a slider crank RRT kinematic chain. The kinematic chain RRT´s joints are connected with the crank and coupler of the slider crank. By means of changing the geometrical lengths of the mechanism´s links, the coupler point M describes a range of coupler curves. The image shows a scheme of the mechanism, generated with the analysis software KOSIM for the geometrical variant: l1 = 30 mm, l2 = 100 mm, l1´ = -45 mm, l4 =100 mm, x = -15 mm.