发明名称 |
Pressure compensator for rotary earth boring tool |
摘要 |
A pressure compensator installed in the bit body of a rotary earth boring tool to lubricate the bearing surfaces of a rotary cutter and to effect a liquid seal. In order to reduce the number of component parts and to enhance durability, the pressure compensator includes a rubber diaphragm interposed between upper and lower capsule halves that form a spherical space.
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申请公布号 |
US4407375(A) |
申请公布日期 |
1983.10.04 |
申请号 |
US19810293263 |
申请日期 |
1981.08.17 |
申请人 |
TSUKAMOTO SEIKI CO., LTD. |
发明人 |
NAKAMURA, OSAMU |
分类号 |
E21B10/22;E21B10/24;(IPC1-7):E21B10/22 |
主分类号 |
E21B10/22 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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