发明授权
US4117897A Drill bit 失效
钻头

Drill bit
摘要:
A drill bit comprising a body suspended in a well bore by an electrical cable which transmits power to a motor secured to the body and eccentric cam member rotated by the drive shaft of the motor and engagable with a plurality of reciprocal drill pins whereby the pins are sequentially impinged against the sidewalls and bottom of the well bore for producing a drilling operation.
信息查询
0/0