Abstract: One or more breakable cartridges containing a two component resin system are inserted in a bore hole drilled in a rock formation by an elongated roof bolt. An expansion shell assembly is positioned on the end of the bolt and includes a shell formed by a plurality of bendable fingers surrounding a camming plug. The camming plug is threadably engaged to the end of the bolt. A clip member is non-rotatably secured to the shank of the bolt and extends into one of the longitudinal slots that separates the fingers of the shell. After the cartridges and bolt are advanced into the bore hole, the cartridges are compressed between the end of the bore hole and the end of the bolt and fractured to release the resin components.

Abstract: A reinforcing rod having a threaded end portion with a coupling secured thereto is inserted in a drill hole of a rock formation, such as a mine roof, with the threaded end adjacent the emergent end of the drill hole and the opposite end in contact with cartridges containing a resinous composition positioned within the drill hole. A bolt having a threaded end portion is engaged to the coupling. A roof plate is retained on the opposite end of the bolt extending from the drill hole. A shear pin is positioned transversely in the coupling and maintains the adjacent end portions of the rod and the bolt in spaced relation to permit rotation of the connected rod and bolt in the drill hole to fracture the resin cartridges. Contact of the threaded end of the bolt with the shear pin maintains the roof plate spaced from the face of the rock formation as the resin is mixed and allowed to cure to adhesively bond the rod to the rock formation.