Expansible anchor and method of making the same

摘要

An expansible anchor of metal for anchoring in a hole drilled in masonry has a bolt with several connected expander cones forming a thread and an expansible sleeve provided with an internal thread matching the expanding cones. To achieve high holding fores and low draw-in force, expansible portions are formed at uniform intervals along the internal thread of the expansible sleeve by U-shaped channels. The expansible sleeve is manufactured from powdered metal in an injection molding method using a system of binders combined with subsequent removal of binders and sintering, and an injection-molding tool having a removable thread core for the internal thread of the expansible sleeve.