| 摘要 |
1446228 Boring earth &c OIL PATCH INDUSTRIES Ltd 23 Nov 1973 [26 Feb 1973] 54416/73 Heading E1F A drill pipe stabilizer comprises an inner elastic or plastics body 5 adapted to slide on the pipe, and an outer rigid or steel body 3 having ribs 2, the bodies being detachably connected. |
