Patent ID: 7682116

Claim:
An anchor device comprising an expansion bolt which in turn comprises a tubular body, which is provided with a hole which extends along the longitudinal axis of the tubular body to accommodate a fastening screw; the tubular body comprising a central shank and a head integral with said central shank; said head comprising a full solid body through which a pair of longitudinal reciprocally perpendicular through slots are made which delimit at least four anchor segments adapted to spread outwards under the bias of the fastening screw; and in which said central shank comprises a first portion, which is arranged next to said head and presents a plurality of longitudinal through slots essentially orthogonal to a middle plane of the bolt, each of which develops along said first portion parallelly to said longitudinal axis so as to define with an adjacent longitudinal through slot a longitudinal anchoring tab, which is adapted to expand radially outwards under the bias of the fastening screw in which said first portion of the central shank of said bolt presents two end segments having a toothed profile in which the crests are arranged at a first distance one from the other; and a central segment arranged between the two end segments having a toothed profile in which the crests are arranged at a second distance higher that said first distance.