| 发明名称 |
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| 摘要 |
A rotary drill bit for producing a raise bore about a pilot hole comprises a drill head having an upper surface for mounting cutter assemblies and lower surface spaced from said upper surface. The upper and lower surfaces are secured to and connected by a body sub. A drive stem is removably secured in the drive sub. The drive sub and stem have mating tapered portions for a press fit. Either the sub or the stem is provided with a spiral groove through which oil is injected under high pressure to expand the sub while the stem is rammed into place under high pressure. The stem can be removed by application of oil pressure and a ram force in the opposite direction. |
| 申请公布号 |
JPS5949398(B2) |
申请公布日期 |
1984.12.03 |
| 申请号 |
JP19770021660 |
申请日期 |
1977.03.02 |
| 申请人 |
REED TOOL CO |
发明人 |
BAIRON UEN CHITSUTOTSUDO;TOOMASU EDOWAADO UINSHITSUPU |
| 分类号 |
E21B10/10;E21B7/28;E21B17/04;E21D3/00;F16D1/091;F16D1/092 |
主分类号 |
E21B10/10 |
| 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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