Expansion anchor

Claim 1

An expansion anchor, comprising an expansion anchor sleeve having a trailing end, a leading end having an opening and being arranged to be inserted into an expansion anchor hole in a support structure, and four circumferentially distributed slots extending from said leading end toward said trailing end and subdividing a longitudinally extending section of said sleeve into four tongues; rupturable webs connecting adjacent ones of said tongues in the region of said trailing end; an elongated through-passage provided in said sleeve and including a first inner circumferential conical surface portion in the region of said leading end and a second inner circumferential conical surface portion closer to said trailing end, both of said surface portions converging towards said trailing end and being located in said section and an intermediate cylindrical surface portion extending between the narrower rear end of said first conical surface portion and the wider front end of said second conical surface portion, an internally threaded first expander member located in said passage within said first surface portion and a second tubular expander member located in said passage within said second surface portion, both of said expander members diverging in direction towards said leading end; a tubular spacing member located in said passage intermediate and abutting with its opposite ends against said first and second expander members; and an elongated bolt member having a rear portion freely extending from said trailing end through said second expander member and said tubular spacing member, and a screwthreaded front portion extending into and meshing with the screw threads of said first expander member, said through passage and said surface portions having such cross-sectional dimensions as to admit of insertion of said expander members and said spacing member into said passage from said leading end of said sleeve.