| 摘要 |
1302433 Making tubes KABEL-UND METALLWERKE GUTEHOFFNUNGSHUTTE AG 8 Oct 1970 [9 Oct 1969] 47907/70 Heading B3A [Also in Division F2] Metal tubing is made by forming a strip M, whose thickness is less than 0À30 mm, into a tubular form with the longitudinal edges forming radially extending tabs 15, and welding the exposed edges 16 of the tabs to form a seam. A tape M is bent around a mandrel 20 by known folding means 21 and is formed into a tubular configuration having tabs 15, the latter being trimmed by cutting means 23 having two rotatable cutter discs 30, 31 (Fig. 5). The trimmed edges are welded together by means 26 under a protective atmosphere of argon and the resultant tab seam is folded against the outer surface of the tube by a die 27. A thin layer of metal adhering resin is supplied to the tube by an extruder 28 after which a thicker layer of resin is applied by an extruder 29. The tape used can be aluminium, copper or stainless steel.
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