| 摘要 |
A socket-shaped centring part (7) is insertable in the old cut-off column (3) to centre and at least partly support the lower end of the new column (6). The centring part is open so that it can be spread to a mainly flat state and has alternating axially directed ribs and articulated parts. - The centring part in the spread state is approximately rectangular and the ribs are separated via tracks, at the bottoms of which are located the articulated parts. The ribs in their upper ends in the usage position have wedge-shaped parts with upwards and downwards increasing radial thickness, so that together they form an inner, approximately blunt conical surface. |
