Expanding bolt with plastics sleeves - has cones of hard plastics to expand cylinders of resilient plastics material

摘要

An expanding bolt for attaching objects to concrete surfaces or walls consists of a screwed rod (1) with a nut (2) and a number of plastic sleeves or collars (3, 4, 5, 7). Conical collars (3) alternate with cylindrical collars (4). The cylindrical collars (4) are made of a resilient plastic with four longitudinal grooves which create lines of weakness. The conical collars (3) are made of hard plastic so that when the nut (2) is tightened the small end of the cone is forced into the adjacent cylindrical collar (4) which is expanded by breaking along the lines of weakness and four tongues are formed which grip the side of the hole in which the bolt is placed.