During Assembly or disassembly of the structure when access to the screws or threaded holes complicate other parts, very useful screwdriver with gripper, acting on the principle of a collet pencil.
The tool consists of a handle and a rod on which slides the collet with petals. Move tube collets ago limited focusing of the rod, and forward — the size of screw propeller. For his capture pulls the body of the screwdriver back, and arm: petals collets apart and the working part of the screwdriver is exposed. Inserting the tip of a tool into the slot of the screw, release housing. Under the action of the spring it is its edge will squeeze the petals collets, and they will be compressed and will hold the screw until the ENT until the head will not begin to approach the fastening plane. The last cycles of the head restraint pushes her petals until you slip the screw into place, the seizure was released.
The collet screwdriver:
1 — arm, 2 — rod, 3 — spring 4 — washer 5 — housing, 6 — petals, 7 — screw.