Nut 2 is connected by a screw pair to stud 1 which is screwed tightly into the base. Stud 1 passes with a certain clearance through the hole in wedge 3. Workpiece 4 is clamped by wedge 3 when nut 2 is tightened. Spring 5 raises wedge 3 to its initial position when nut 2 is released.
$241$SL,GC$