Rigidly attached to link 1 is pin a, screw c and special nut d. Using nut d, link 1 is held with its horizontal surface tight against fixed link 3 and can be moved only horizontally. Screw b is a stop restricting the motion of link 1. Link 1 has a tapered surface e sliding along the inclined surface of link 2 which, in turn, slides in fixed guide f. When link 1 is displaced horizontally, link 2 moves vertically.
$2168$WL,3L$