Expansible anchor and method of making same

摘要

The expansible anchor consists of a shank having a threaded portion for fixing an article at its rear end and a reduced cross-sectioned portion with an adjoining expander cone at its front end, and, positioned over the reduced cross-sectioned portion, an expansible sleeve having longitudinal slits forming expansible segments and locking elements protruding beyond the diameter of the expansible sleeve and arranged on the expansible segments. To increase the holding force of the anchor and to allow the expander cone to slide-up and the expansible sleeve to expand in operation if the drilled hole become enlarged as a result of cracks forming, the locking elements consist of several interconnected punched elements on each expansible segment extending in a longitudinal direction of the expansible segments. Each punched element is triangular with a point directed towards the front end of the expansible segments. An improved method of making the expansible anchor which includes stamping a blank for the expansible sleeve somewhat undersized from sheet metal, subsequently pressing it and then punching the punched elements in the expansible sleeve is also described.