| 摘要 |
<p>A threading equipment has displaceable assembly having upper section (32) including cutting mechanism and control mechanism (56, 58); mechanism for controlling vertical displacement speed of the assembly; and mechanism for controlling rotation speed and sense of rotation of the assembly about its vertical axis. The threading equipment comprises displaceable assembly having upper section including cutting mechanism and control mechanism to move the cutting mechanism from retracted position, the cutting mechanism disposed radially inwardly of a wall (40) and an extended position, and projects into the wall; mechanism for controlling vertical displacement speed of the assembly; and mechanism for controlling rotation speed and sense of rotation of the assembly about its vertical axis (46). In the extended position, the cutting mechanism is arranged to cut thread in the wall. The thread has a controlled pitch along a controlled length of the pile shaft. An independent claim is also included for an apparatus for cutting thread-like groove in all defining pile shaft comprising rotatable cutting portion having cutting mechanism movable between retracted non-cutting position and extended cutting position and mechanism for controllably moving the cutting mechanism between these positions according to direction of the cutting position.</p> |
