Dowel with tapered plug for fixing objects to walls - is expanded radially by shank of bolt engaging internal ridge

摘要

The dowel (2) has a tapered bore at one end to receive a tapered plug (3) which has an internal screw thread (90). The other end of the dowel (2) has an internal helical ridge (45) and short external ribs (6). When the dowel is fitted into a through hole in a wall and a bolt inserted, the bolt thread engages the helical ridge (45) until the bolt is forced into the thread (90), since the ribs (6) prevent rotation of the dowel. Further rotation of the bolt forces the plain portion of the bolt shank into the reduced diameter at the helical ridge (45). The end section of the dowel is expanded radially and grips the surface of hole in the wall.