公开(公告)号：US3753470A

公开(公告)日：1973-08-21

申请号：US3753470D

申请日：1971-11-29

Applicant: SANDVIK AB

Inventor： LAGERSTROM G ,  INGVAR WIREDAL H

IPC: E21B10/66 ,  E21B9/26

CPC classification number: E21B7/20 ,  E21B10/327 ,  E21B10/40 ,  E21B10/66

Abstract: For use in drilling through earthy material into underlying rock, the eccentric drill tool of the present invention is generally characterized by two cutting portions, with a central portion which is fixed in relation to the drill rod and an eccentric portion which can be shifted between protruding and retracted positions.

Abstract translation: 本发明的偏心钻具通常具有两个切割部分，其中心部分相对于钻杆固定，偏心部分可在凸出部分之间移动， 和缩回位置。