Nut 1 is connected by a screw pair to bolt 4. Bolt 4 passes with clearance through an elongated hole in lever 2. Lever 2 slides with its slot b along screw support a which is screwed tightly into the fixed link (base). The symmetrical arrangement consists of nuts 1 ' , lever 2 ' and bolt 4 '. Bolts 4 and 4' pass through holes in link 5 which bears against button d. The device is adjusted by nuts 1 ', one serving as a locknut. Workpiece 3 is clamped by levers 2 and 2 ' when nut 1 is tightened. Screw supports a and a' serve to adjust the device so that levers 2 and 2 ' are approximately horizontal in the clamped position. Springs 6 and 6' raise levers 2 and 2' to their initial position when nut 1 is released.
$206$SL,GC$