| 摘要 |
<p>Tool (21) for slitting and laterally expanding underground steel gas mains (27) and inserting replacement plastic piping (77) into the spread apart pipeline has a forward end cylindrical portion (45a) mounting a single, rearwardly angled blade (56) to make only one line of cut (80) and a conical pipe spreader portion (50) at its rearward end (21b). The conical spreader portion (50) is eccentrically disposed with respect to the forward end cylindrical portion (45a). A single roller type pipe slitter (60) aligned with the fixed blade (56) may be mounted on a removable extension (45b) of the forward end cylindrical portion (45a), to initially groove and weaken the pipe along the intended line of cut. A pneumatically operated impact ram (22) is attached to the rearward end (21b) of the tool (21), as is the leading end of the replacement piping (77). A wire cable (25) pulls the tool (21) through the underground pipe, thereby grooving, slitting and laterally expanding the pipe (27).</p> |
