| 摘要 |
<p>A pipe burster (10) for cracking gas and other pipes preparatory to inserting a replacement pipe in the passage so formed. The burster (10) comprises an elongated body tapering in the lengthwise direction and made up of first and second parts (2,14) extending in said direction. The parts are connected by a transverse pivot pin (20). The first part (12) is received within the second part (14) and carries a piston and cylinder (22) by which the parts are separable. The circumference of the body is substantially a closed curve and within the length of the first part (12) the circumference is increased by said separation. Therefor the burster (10) makes a clearance by said separation into which the burster (10) can be advanced. In a modification more than one piston and cylinder (70,72,74) is provided.</p> |
