| 摘要 |
1,134,204. Boring earth &c. E. J. LONGYEAR CO. 15 Aug., 1966 [27 Aug., 1965], No. 36461/66. Heading E1F. In core-taking apparatus having a core lifter case 76 and a core lifter 85, the lifter bears during drilling against a hardened steel split ring 78 housed in groove 77.
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