Friction rock stabilizer

Claim 1

An improved friction rock stabilizer for forced insertion thereof into an undersized bore in an earth structure, such as a roof or wall of a mine shaft or tunnel, for stabilizing the structure, said stabilizer comprising a hollow, elongate body formed of a single wall which, in cross-section, is substantially annular, which body has means extending generally lengthwise, for at least half the length thereof, responsive to circumferential compression of said body, arising from such forced insertion thereof into such a structure bore, to cause at least a portion of said body to assume a diminished periphery to accommodate such forced insertion, and to cause said body frictionally to engage the surface of such a structure bore to stabilize the structure, and which body has a driven end with a terminal, impact surface thereat for accepting bore-insertion forces thereupon, wherein the improvement comprises means made integral with an external surface of said driven end of said body for reinforcing said driven end to accept bore-insertion forces addressed thereto and for fixing a support plate against the structure, said reinforcing means is slightly spaced from said terminal, impact surface to isolate said reinforcing means from bore-insertion forces addressed to said impact surface at least during a principal portion of bore-insertion of said stabilizer, whereby upon said reinforcing means closing upon a support plate, or a surface of an earth structure in which said stabilizer is forceably inserted, said reinforcing means and said terminal, impact surface merge toward a position in which said reinforcing means and said terminal, impact surface can accept bore-insertion forces in common.