| 摘要 |
<p>Telescopic well or column pipe comprising an outer tube and an insert tube (B) axially displaceable therein, and a covering which receives in a socket (12) thereof the upper end of the insert tube. Between the socket and the insert tube there is provided as an axially locking rotary mounting an extruded rib (18) having round cross section and smooth surface and consisting of a plastic material having good bearing properties, said rib being received in an annular groove (15, 16) which is located partly in the curved surface of the socket and partly in the curved surface of the insert tube, said groove being available for the insertion of the rib through a passage (17) joining the annular groove substantially tangentially and opening at the outside or the inside of the socket of the insert tube. The insert tube engages at the upper end surface (14) thereof an annular shoulder surface (13) on the covering.</p> |
