发明名称 |
DRILL ELEMENT FOR PERCUSSION DRILLING |
摘要 |
This invention relates to a drill element (10; 11; 12) for percussion drilling, said element having a cylindrical screw thread (13; 14; 15) having one single entry. The screw thread, that is intended for thread diameters of less than 30 mm, has a pitch (s) of less than 12 mm, a shoulder angle ( beta ) of more than 21 DEG , and a pitch angle ( alpha ) of less than 11 DEG but more than 5.6 DEG . |
申请公布号 |
EP0187628(A3) |
申请公布日期 |
1987.04.08 |
申请号 |
EP19850850399 |
申请日期 |
1985.12.17 |
申请人 |
SANTRADE LTD. |
发明人 |
JANSSON, KJELL-OVE;LILJEBLAD, LARS;LILJEKVIST, SOREN |
分类号 |
E21B17/042;(IPC1-7):E21B17/042;F16L15/00 |
主分类号 |
E21B17/042 |
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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