| 摘要 |
A cutting/expanding tool includes a cylindrical support body having a guide side and a cutting side, a pair of guide rollers mounted in tandem along the longitudinal axis of the support body on the guide side, a cutting wheel mounted between the tandem guide rollers on the cutting side of the support body, and an expander connected rearwardly of the support body. A plurality of cutting wheels may also be provided, each of progressively increasing diameter. A scoring wheel may be mounted forwardly of the cutting wheels to prescore the surface to be cut, so as to facilitate the cutting action, and a deburrer may be mounted rearwardly of all the cutting wheels so as to smooth the cut edge. A method of using the cutting/expanding tool is also described, whereby after the tool has been propelled through a buried main to cut and to expand it, a replacement main is drawn back through the existing main. A conical, wedge or pie shaped expander may be used.
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