Link 1 is connected by a screw pair to end b of stud 2. With its slot d, stud 2 slides along the tip of setscrew f which is screwed into the base. Workpiece 3 is first screwed on end e of stud 2 which then pulls the workpiece against the locating surface when the lever of link 1 is turned (screwed on).
$220$SL,GC$