发明名称 Drill head assembly
摘要 A drill head assembly especially adapted but not limited to horizontal drilling with placement of casing is illustrated as including a drill head body, a wing cutter assembly, and a drive shank all having interlocking connections and assembled by a longitudinal assembly screw.
申请公布号 US4773491(A) 申请公布日期 1988.09.27
申请号 US19870049465 申请日期 1987.05.14
申请人 SHY, MAX H. 发明人 SHY, MAX H.
分类号 E21B7/20;E21B10/26;E21B10/62;(IPC1-7):E21B10/26 主分类号 E21B7/20
代理机构 代理人
主权项
地址