| 摘要 |
1279498 Scaning non-metallic sheet material INDUSTRIELE ONDERNEMING WAVIN NV 23 Sept 1969 [30 Sept 1968] 46711/69 Heading B5K [Also in Division F2] In the manufacture of plastics tube a smooth tube 1 is located within a helically or transversely grooved tube 2 and the tubes 1, 2 joined locally by pressing upon them with a heated fin assembly. A suitable apparatus includes a hollow rotating nut 9 carrying the assembly which has two pins 11 which are biased by spring 15 away from the tubes 1, 2. During rotation of the nut 9 relative to casing 7, the end 13 of the pin assembly bearing against its surface. Since this surface has ridges 14 (best seen in Fig, 3 (not shown) the assembly is intermittently forced into the tubes 12, and forms the bond between the tubes 1, 2. Alternatively, Fig. 4, 5 (not shown), a number of radially movable pins may be carried by the casing and the rotating nut has a disc member (17) having an irregular circular groove (16) in one face. Each pin engages with this groove whose irregularities cause depression of the pins. Tube 1 may be of PVC and tube 2 of polythene or both tubes may be of the same plastics material. |
