| 摘要 |
A pipe propelling device comprises two sets of jack assemblies spaced from each other and arranged in the direction of propelling the pipe in a vertical shaft having a reacting shaft wall so that the small diameter pipe such as water supply and drainage pipes, gas pipes and cable laying pipes can be propelled from the interior to the exterior of the vertical shaft by the extension of two sets of the jack assemblies. To reduce the dimension of the vertical shaft due to propel the pipe, eliminate the interposition of a strut in propelling the pipe and secure an operative space in the vertical shaft, the jack assemblies comprise a plurality of first stage jacks connected to the reacting shaft wall and at least one second stage jack, a cylinder of the second stage jack being connected to cylinders of the first stage jacks.
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