摘要 |
One end of the inner pipe (10) is in the form of a sleeve (12) whose inner diameter at least equals the external diameter of the inner pipe at its free end. The sleeve has a funnel-shaped cap (18) whose internal diameter is at most equal to the sleeve's inner diameter and at least equal to the external diameter of the free end (14) of the inner pipe. The funnel shaped surface of the cap is truncated-cone shaped and is in the form of a thin-walled, sheet metal tube (20) which has an inward pointing bead (22) above the cap. The sleeve is enclosed by a collar (24) near which is an inward-pointing clamping strips (26). Elastic centering elements (28) are distributed over the cap's periphery and held in holders (32) in an extended section (30) of the tube. |