| 摘要 |
1,064,398. Drilling machine details. E. PASS & CO. Ltd. Dec. 17, 1965 [Dec. 18, 1964], No. 51691/64. Heading B3C. [Also in Division F2] Under pressure drilling equipment 40 is adapted to be supported on a pipe-embracing assembly 10 including a valve 14. The latter, when opened, allows the drilling by a cutter 48 of two holes 49, 50 in the pipe 17 at oppositely disposed locations therein. |
