| 摘要 |
1,194,688. Seaming. ATLANTIC RESEARCH CORP. 8 Nov., 1967 [13 Jan., 1967], No. 50810/67. Heading B5K. [Also in Division F2] Two shaped articles 10, 12 of thermoplastic resin are welded together by interfitting the articles 10, 12 with a welding sleeve 11, consisting of a heating conductor enclosed in a layer of thermoplastic resin, lying therebetween, electrically heating the conductor to melt the thermoplastic resin of the sleeve 11 and a portion of the articles 10, 12 adjacent thereto, applying external pressure to the articles 10, 12 to squeeze the articles and the sleeve 11 together to ensure intimate contact therebetween during the melting of the thermoplastic resin, and continuing heating until the thermoplastic resin of the sleeve 11 and the articles adjacent thereto has melted sufficiently to weld the articles together. In the embodiment shown, a joint is formed between a pipe 10 and a pipe fitting 12. The sleeve 11 is made by winding a strand of wire covered with thermoplastic material into a core and then fusing the strands together. The pipe 10 is inserted into a deep bore 17 in the fitting 12 and the sleeve 11 is positioned around the end thereof and accommodated in a shallow bore 18 in the fitting 12 so that electrical supply leads 19 extend outwardly. External pressure is applied by a clamp 13 located around the portion to be welded. The clamp 13 comprises a threaded T-handle 14 and an associated quick-release fastener 15. After tightening of the clamp 13, electrical power is applied to the leads 19 to effect welding. Approximately half-way through the heating step the clamp 13 is tightened further to eliminate air bubbles in the weld and to compensate for improper sizing between the pipe 10 and the fitting 12. In a modification (not shown), the sleeve 11 is moulded to one of the articles to be joined, e.g. around the exterior of the pipe 10 or in the bore 18 of the fitting 12.
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