Shallow undercut concrete anchor

A method of installing an anchor in a post tensioned concrete structure comprising the steps of:

• providing a post tensioned concrete structure including a concrete surface, drilling a cylindrical opening in the concrete surface, the opening having a depth of 0.75 inches or less,
• the concrete cylindrical opening further including an open end and a closed end and a cylindrical wall having a radius, and
• providing an anchor including a sleeve and a plug,
• the sleeve including at least two legs extending toward a first end of the sleeve and the sleeve also including a second end opposite the first end, the sleeve further including a cylindrical through opening from the first end to the second end,
• the plug including a first end for engaging the legs and a second end opposite the first end, the plug received in the cylindrical through opening, the plug further including a locking portion for connecting the anchor to the object,
• a tapered portion disposed on at least one of the plug and the legs, and
• forcing the plug and sleeve telescopically relative to each other so that the legs are forced radially outward, and so that the tapered portion prevents inward movement of the legs to lock the sleeve and the plug to the wall of the concrete cylindrical opening.

An anchor system for securing an object to a structure comprising in combination:

• a concrete structure including a concrete cylindrical opening in a surface thereof, the concrete cylindrical opening including an open end and a closed end, and a anchor including a sleeve and a plug,
• the sleeve including at least two legs extending toward a first end of the sleeve and the sleeve also including a second end opposite the first end, the sleeve further including a cylindrical through opening from the first end to the second end,
• the plug including a first end for engaging the legs and a second end opposite the first end, the plug received in the cylindrical through opening, the plug further including a locking portion for connecting the anchor to the object,
• a tapered portion disposed on at least one of the plug and the legs,
• wherein when the plug and sleeve are forced telescopically relative to each other, the legs are forced radially outward as a result of the tapered portion.