Slotted link 1 oscillates about fixed axis A. The slot of link 1 receives cylindrical pin b of slider 2 which reciprocates in straight guiding slot a-a of the base. The displacement of point B of slider 2 with respect to its middle position B' equals x=k*tan(α) where α=angle of rotation of link 1 k=distance from point B' to axis A.
$921$LG,3L$