Link 1, connected by a screw pair to the base, has conical tip a which enters V-shaped groove d in plunger 2. Plunger 2 slides vertically in a hole in the base, its slot b being guided by the tip of setscrew c in the base. Workpiece 3 is screwed on threaded shank f of plunger 2. When link 1 is turned (screwed in), plunger 2 draws workpiece 3 down tight against the locating surface. Spring 4 raises plunger 2 to its initial position when link 1 is released.
$237$SL,GC$