| 摘要 |
A pipe driving device comprises two sets of triple ram assemblies (12, 14) spaced from each other and arranged in the direction of the pipe (30) motion in a vertical shaft having a reacting shaft wall so that the pipe (30) such as a water supply and or drainage pipe, gas pipe and cable duct can be driven from the vertical shaft.
<??>To reduce the diameter of the vertical shaft necessary to gain operating space in the vertical shaft, the ram assemblies (12, 14) comprise a plurality of first stage jacks (22, 24) connected to the reacting shaft wall and at least one second stage jack (26), a cylinder (26b) of the second stage jack being connected to cylinders (22b, 24b) of the first stage jacks. |
