| 摘要 |
1,150,918. Seaming non-metallic sheet material. ARENCO A.B. 17 Oct., 1966 [1 Nov., 1965], No. 46308/66. Heading B5K. A collapsible tubular container 5 provided with a longitudinal welded seam 6 and having a laminated wall comprising an inner layer of plastics material having a low dielectric loss factor, a metal layer situated outside the plastics material and possibly a layer of paper and/or plastics material situated outside the metal layer, is transversely sealed by pressing two jaws 7, 8 against the container 5 in such a way that when the region to be sealed is pressed flat the seam 6 abuts the jaw 7 and then applying a high frequency current of short duration to a conductor 13 in the pressure surface of the jaw 8 so that currents are induced in the metal layers in the region of the jaws 7, 8 to heat the adjacent inner plastics material layers and form a welded seam. As shown, each tube 5 is mounted in a cylindrical insert 4 rotatably mounted in a holder 2 mounted on two chains 1. The jaws 7, 8 are slidably mounted on a rod 9 and actuated by links 10 connected to pivoted arms 11 mounted on a stationary shaft and driven by means not shown. The jaw 7 comprises an insulating material resiliently mounted against the action of springs 12. The jaw 8 is provided with a copper conductor 13 of square or rectangular cross-section and connected by blocks 15 to a high frequency current source. The chains 1 are driven stepwise so that two tubes at a time are advanced to the jaws 7, 8, Fig. 2 (not shown). A device 16 is arranged to optically sense the position of a mark 17 of the tube 5 and controls a motor 18 which, through a gear 19 and a drive wheel 20 engaging a friction surface 21 on the holder 2, rotates the holder 2, if necessary, until the device 16 detects the mark 17 to position the tube 5 with its seam 6 facing the jaw 7. This prevents excessive heating of the seam 6 during transverse sealing of the tube 5. The conductor 13 is cooled by connection to a water-conduit (22), Fig. 2 (not shown). |
