| 摘要 |
1,041,159. Making helically seamed tubes; welding by pressure. RAYMOND INTERNATIONAL Inc. May 14, 1965 [June 9, 1964], No. 20371/65. Headings B3A, B3E and B3R. Apparatus for making helically wound welded tube comprises an assembly for advancing the strip 35 at an angle to the finished tube axis. A forming tool 62 is provided with a number of interchangeable inserts (Fig. 15, not shown), which form a generally semi-cylindrical cavity, to form the strip into continuous convolutions. The successive convolutions are preferably overlapped and welded where they meet between rollers 63, 64, highfrequency current being supplied to the edges of the sheet shortly before they come into contact (Fig. 9, not shown). The inner roller is carried on a mandrel member 65, which is mounted on a table 43, whereas the tool 62 is fixed in a frame 66. The strip advancing assembly is pivotable on rollers 55 about an axis 54 passing vertically through the welding point. The strip is advanced by rollers 39 and is kept flat by rollers 45 carried in adjustable bars 44. |
