Screwdriver for socket head capscrews - has locking device preventing axial movement of screw gripping sleeve and is releasable

摘要

The screwdriver has a sleeve gripping the screw head and sliding axially in opposition to a spring on a blade insert. When the screw is thrust against the end of the tapped hole, the sleeve slides back far enough for the rotating insert to engage with the slot, staying engaged until the screw is run right down. A locking device, released by the hand grip, stops the sleeve sliding axially, and can be in the form of a catch. There can be a further sleeve (21) between the first one and the blade insert (2), the segments of the first sleeve being pre-loaded against it. The end face of the second sleeve also acts as a stop for the screw head. The ends of the segments of the first sleeve can have edges extending radially inwards.