Self-cutting expansion anchor

A self-cutting expansion anchor, for solid wall installation, comprising;

• an elongated anchor bolt having an outer head end and an opposite inner screw-threaded distal end, and an intermediate screw-threaded portion;
• ramp means screw-threadably mounted on said distal end of said bolt and providing at least one camming surface angularly outwardly extended from the bolt;
• non-rotatable thrust means including a nut having gripping means thereon screw-threadably mounted on said intermediate portion of the bolt in longitudinally spaced relation to said ramp means;
• expandable cutter means axially slideably mounted on said bolt in sliding engagement with and extending between said ramp means and said thrust means and having at least one cutting blade slideably engaging said camming surface of said ramp means, said blade including an integral activating ring circumscribing said bolt and axially engaging said nut of said thrust means with the blade having sufficient flexibility to progressively flex radially outwardly of the bolt during traversement along said camming surface;
• said bolt having right-hand threads on its inner distal end;
• said ramp means is an internally screw-threaded ramp nut screw-threadably mounted on said inner distal end of the bolt;
• and said intermediate portion of said bolt has left-handed screw-threads on which said thrust nut is screw-threadably mounted.

A self-cutting expandable anchor comprising;

• an elongated bolt having a head end, an intermediate portion provided with left-hand screw-threads thereon, and an opposite distal end provided with right-hand screw-threads thereon;
• an internally screw-threaded ramp nut screw-threadably mounted on said distal end of said bolt and having a left-handed screw-threaded portion;
• a left-handed screw-threaded fracturable plug screw-threadably mounted in said left-handed screw-thread portion of the ramp nut in temporary locking engagement with said distal end of the bolt;
• said ramp nut including a plurality of elongated longitudinally extended grooves formed therein in circumferentially spaced relation to each other individually providing angularly radially outwardly diverging camming ramp surfaces;
• a plurality of elongated flexible combined cutting blades and expandable gripping members disposed in circumferentially spaced relation to each other and having an integral annular actuating ring loosely journalled on said intermediate portion of the bolt interconnecting said blades in individually axially sliding engagement with said camming surfaces on the ramp nut, each of said blades including a stop member thereon adjacent to said actuating ring;
• and an internally threaded thrust nut screw-threadably mounted on said intermediate left-handed screw-threaded portion of said bolt in axially facing engagement with said actuating ring of the blades and having a pair of opposed anti-rotation stop members peripherally extended therefrom permitting axial advancement of the thrust nut toward said ramp nut during rotation of the bolt.

A self-cutting expandable anchor comprising;

• an elongated bolt having a head end and an opposite distal end provided with right-hand screw-threads thereon;
• an internally screw-threaded ramp nut screw-threadably mounted on said distal end of said bolt and having a left-handed screw-thread portion;
• a left-handed screw-threaded fracturable plug screw-threadably mounted in said left-handed screw-thread portion of the ramp nut in temporary locking engagement with said distal end of the bolt;
• said ramp nut including a plurality of elongated longitudinally extended grooves formed therein in circumferentially spaced relation to each other individually providing angularly radially outwardly diverging camming ramp surfaces, and an elongated cylindrical skirt axially extended from the ramp nut and having left-handed screw-threads thereon;
• a plurality of elongated flexible combined cutting blades and expandable gripping members disposed in circumferentially spaced relation to each other and having an integral annular actuating ring loosely journalled on said skirt interconnecting said blades in individually axially sliding engagement with said camming surfaces on the ramp nut, each of said blades including a stop member thereon adjacent to said actuating ring;
• and an internally threaded nut screw-threadably mounted on said left-handed screw-threaded skirt of said ramp nut in axially facing engagement with said actuating ring of the blades and having a pair of opposed anti-rotation stop members peripherally extended therefrom permitting axial advancement of the thrust nut toward said ramp nut during rotation of the bolt.