Unitary drill bit and roof bolt

Abstract

A combined drill bit and roof bolt and a method for forming a bore hole in a mine roof and for reinforcing same. The drill bit and roof bolt form the same structural element which preferably comprises an elongate hollow tube. On one end of the tube is formed a multi-bladed bit. The diameter of the hole cut by the blades is somewhat larger than the diameter of the elongate tube. Formed intermediate the blades on the bit head are a plurality of apertures. The apertures perform the dual function of providing an exit passageway for rock chips as the drilling proceeds, as well as providing a means through which a quick-setting adhesive resin is extruded from inside the hollow bolt to the newly drilled annular hole extending thereabout. The extrusion is accomplished by means of a pig element forced up the tube. In a preferred embodiment, the pig element is formed by a wedge-type top anchor which thereafter drives a split shell positioned therearound in order to tension the bolt prior to the hardening of the adhesive resin.

Dependencies are inferred from the claim text.