| 摘要 |
<p>A method and apparatus for forming bores in coal seams and the like and enlarging pre-existing bores. A mining machine includes a non-rotatable body member, a conveyor, such as an auger, in line with the body member, and a pair of wing cutters mounted on the body member for pivotal movement with respect thereto. The wing cutters are movable from a first position wherein they are generally in line with the body member and conveyor, to a second position wherein they are disposed outwardly with respect to the body member. The wing cutters will be in their first position during movement into a bore, and will be moved to and latched in a second position during movement out of the bore. A pilot cutting head in front of the body member may also be provided. The wing cutters may comprise rotatable drums driven by cutting chains, and the drums are normally powered to rotate outwardly from the body member, in directions opposite to each other. bore may be formed by in-cutting and subsequent outcutting with the wing cutters in a second position, or a pre-existing bore may be enlarged by moving the machine into the bore, then moving the wing cutters to a second position and withdrawing the machine from the bore.</p> |
