Patent ID: 8162569

Claim:
A high-strength anchor system for anchoring a support to mine strata, said system comprising an anchor plate adapted to be secured to mine strata with an outer face of the plate facing the mine strata and an inner face of the plate facing away from the mine strata, a connecting member on the inner face of the anchor plate for connection of the support to the anchor plate, anchor bolt holes in the anchor plate spaced at intervals around the plate, anchor bolts extending through the bolt holes in the anchor plate into bore holes in the mine strata, fasteners for securing the anchor plate to the anchor bolts, and load-spreading devices extending from respective bolt holes in the anchor plate into respective bore holes in the mine strata, said load-spreading devices having outside diameters larger than outside diameters of the anchor bolts for spreading shear loads exerted on the anchor bolts over larger areas of the mine strata.