| 摘要 |
<p>A roof bolt is installed in a mine by drilling a bore 10 into the rock strata 12, inserting a roof bolt 32 into the bore, and then pumping a setting or curable composition through a duct which extends from end-to-end within the bolt. The composition thus flows out of the inner end of the bolt and into the bore, then flows back over the outside of the bolt to the outer end of the bore. The roof bolt may be formed as a drill bit which is used to drill the bore. The composition is supplied to the duct via a screw connector 36 by means of an injection pump 30 and hose 34. <IMAGE></p> |
