Workpiece 1 is clamped by links 2 and 2' which are brought together when nut 4 is tightened on bolt 5. As they are brought together, links 2 and 2' slide downward with their bevelled surfaces along the guiding surfaces of the base, compressing springs 3 and 3', and pulling workpiece 1 down firmly against its locating surface. Springs 3 and 3' raise links 2 and 2' to their initial position when nut 4 is released.
$214$SL,GC$