| 摘要 |
<p>A mining machine for enlarging a pre-existing bore by out-cutting, said machine comprisinga) a non-rotatable body memberb) a pair of wing-cutters pivotally mounted to said body member, having rotatable cutting portions thereof,c) conveying means mounted behind said wing cutters in operative association with said body member, for conveying coal or the like cut by said wing-cutters away from the cutting site,d) means for pivotally moving said wing cutters with respect to said body member from a first position, wherein said wing cutters are generally in line with said body member and said conveying means and no substantial amount of coal or the like is cut thereby, to a second position wherein each said wing cutter extends outwardly with respect to said body member, making an angle with a line between said body member and said conveying means and in which second position a substantial amount of coal or the like is cut thereby,e) means maintaining said wing cutters in said second position during out-cutting, andf) means for rotating the rotatable cutting portions of said wing cutters. The machine has the advantages of less wasted set-up time for mining with a machine of a given size, the mining of larger bores, the capacity to retrieve coal, ore, etc. from bores that have been made previously. Operators are not required to go into the bores being formed or enlarged which represents an important safety factor.</p> |
