An Improved Method of Forming Screw Threads at the Extremities of Thin Metal Tubes and the like

摘要

6313. Bizet, L. J. March 18. Screwing.-To enable screw threads to be formed on the ends of thin metal tubes and the like, the end is gradually turned inwards and reduced as shown in Figs. 2, 3, and 4, the operations being effected by suitable dies, and the thread tapped in the ordinary way to receive a union, valve, plug, cook, &c. Fig. 7 shows the end of the tube turned outwards, the thread being formed internally as shown, or externally. The tube may be closed at the opposite end, either by a valve such as is shown, or by other suitable means, the tube becoming a closed receptacle for liquid or gas under pressure.