| 摘要 |
<p>1426626 Seaming non-metallic sheet material FATHOM SRL 29 March 1973 [19 April 1972] 15069/73 Heading B5K A device for welding and severing thermoplastic films 27 comprising co-operating bars 1, 11, is characterized in that the bar 1 has a recess 7 to accommodate heating means (not shown), e.g. an electrical resistance, at least one longitudinal welding projection 5 and a longitudinal severing projection 3, in use, the projection 3 being co-operable with a resiliently yieldable portion on the bar 11. In one embodiment, Fig. 1, a cutting edge 3 is flanked by two welding projections 5. The projections 3, 5 may be uncoated or coated with polytetrafluoroethylene. The bar 11 has a silicone rubber layer 13 to co-operate with the edge 3 and small metal bars 17 urged outwardly by compression springs 19 to co-operate with the projections 5. To restrict movement of the bars 17 relative to the bar 11 pins 21 pass through orthogonal slots 23, 25 in the bars 11, 17, respectively. The bars 1, 11 may be made of aluminium or an alloy and the bars 17 of brass. In another embodiment, Fig. 2, the upper bar is identical to that of Fig. 1 and the lower bar 31 has a small metal bar 33 spring urged outwardly to co-operate with the edge 3 and rigid surfaces 37 to co-operate with the projections 5. In a further embodiment, Fig. 3, the upper bar 41 is cut-away at 43 to accommodate the electrical resistance and has one cutting edge 45 to co-operate with a rubber layer 49 and one welding projection 47 to co-operate with a metal bar 53 urged out of a channel 55 by compression springs 57. In a modification, Fig. 4 (not shown) the edge (45) co-operates with a resiliently mounted bar (63) and the projection (47) with a rigid surface (61).</p> |
