Link 1 is connected by a screw pair to the fixed base. Screw 4 is connected by a screw pair to split nut 3 which has tapered external surfaces and slits cut from both ends. When link 1 is screwed in, tapered sleeve 2 compresses split nut 3, thereby reducing the clearance between screw 4 and nut 3, and eliminating backlash between these links.
$2176$WL,4L$