Mine roof expansion anchor, tapered plug element used therein and method of installation

摘要

A mechanical expansion anchor and tapered plug for use therein having particular application in combination with resin grouting materials. The anchor includes conventional shell structure having a plurality of radially expansible leaves with internal surfaces opposing compression surface portions of a tapered camming plug. Components of a resin mix inserted in a drill hole between the blind end thereof and the end of a bolt carrying the expansion anchor flow around the tapered plug and through axial passageways therein. The plug is distinguished by the provision of axial grooves for passage of resin components in the compression surfaces of the plug.