Link 1 is connected by screw pair A to lever 3 which has slot a sliding along fixed pin B. Lug d of lever 3 freely enters slot e of the fixed link (base). Workpiece 2 is clamped by tip b of link 1 when the latter is screwed into lever 3. Slot a enables lever 3 to be shifted along the slot and to be turned to the side together with link 1 when the latter is released.
$193$SL,GC$