Straddling dowel, has expanding mandrel with cross-section taper from rear towards front, and holding region located in front of taper, where holding region changes into expanding surface, with which mandrel is tapered to its front end

摘要

The dowel (1) has a front region designed as an expansion area (5). A longitudinal hole (6) has a step like cross-section contraction (7) from rear towards the front at the transition to the expansion area or forwardly within the expansion area. An expanding mandrel (10) has a step like cross-section taper (13) from rear towards the front, and a holding region (11) located in front of the cross section taper. The holding region of constant cross section changes into a circulating spherical expanding surface (12), with which the mandrel is tapered to its front end.