Round iron suspension device - bent part has bending strength corresponding to tensile strength of bolt shank

摘要

The method of manufacturing a suspension device or roof bolt, the bent part of which has a bending strength substantially corresponding to the tensile strength of the shank of the device or bolt made of commercial round iron, is characterised in that the device is made of one single roundwork piece. The roundwork piece is cold bent to form an end the hook part in the shape of a closed, suitably oval ring, the largest part of which is extending, laterally to the longitudinal direction of the shank. The material of the ring is pressed or rolled by cold working perpendicularly to the plane of the ring and substantially up to the straight part of the shank, so that the section of the work piece in the pressed part becomes almost rectangular. The end of the ring is skewed laterally perpendicularly to the plane of the ring (cross-set), so as to form an opening sufficient for engaging a line, a chain or any other attachment means intended to carry a load.