| 摘要 |
740,726. Pipe joints. SCHOELLERBLECKMANN STAHLWERKE AKT.-GES. Aug. 5, 1953 [Sept. 23, 1952], No. 21635/53. Class 99(1). In a joint for deep well drill stems in which the drill pipe 5 is screwed to the coupling member 1, such as by a tapered spigot 8 on the pipe end engaging in a socket 2 of the member 1, and in which the pipe and coupling member have interengaging, unthreaded sealing surfaces such as the overlapping cylindrical surfaces 4, 7, the latter are forced together by hot working, e.g. pressing, forging, rolling, or drawing, after the parts have been screwed together. |
