| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a new pipe laying device and laying process in a simplified pipe-in-pipe work method, which simplifies equipment and material used for laying work and makes possible manual transporting of the device into construction sites and manual laying work. <P>SOLUTION: This device is provided with a wire for pulling operation to be inserted through an existing pipe and a wire bring-in tool for pulling the wire from a work launch pit to introduce a following new pipe element into the existing pipe by the length of the new pipe element. The wire bring-in tool consists of a body to be installed and fixed on the wire at the center of the tool, and a plurality of engaging parts extending radially from the body. Each engaging part is expandable in diameter, usually held in an expended diameter state by the force of a holding spring and engages with a step within the reception port at the rear end of the following new pipe element with its diameter kept expended. If necessary, this diameter can be reduced against the holding spring as much as the engaging part can pass through a new pipe element. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
