US 4,046,204 AGranted

Controlled directional drilling tool

AssigneeAgency of Industrial Science and Technology

InventorsSabro Takaoka, Akira Shinoda, Hideo Kobayashi

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Abstract

A controlled directional drilling tool is disclosed which comprises a drilling unit consisting of a drilling head incorporating therein a rotary drill bit and bit-driving means and a drilling rod having said drilling head connected freely flexibly to the leading end thereof, a pair of cylinder means adapted to be operated by means of compressed air and a pair of direction-controlling rollers adapted so as to be caused, by the operation of said cylinder means, to protrude at mutually staggered positions from the opposite lateral sides of the drilling unit, said pair of cylinder means and said pair of direction-controlling rollers both provided to the drilling head of said drilling unit, whereby the direction in which the drilling is being made by said drilling head is changed as required by adjusting the protrusion of said pair of rollers.

Claims4

Dependent claims

A controlled directional drilling tool comprising in combination:

a drilling rod,
a joint freely flexibly connected to one end of said drilling rod,
a drilling head connected to the remaining end of said joint and provided at the leading end thereof with a drilling bit and in the interior thereof with a driving means for said drilling bit,
a pair of cylinder means and a pair of piston members both disposed inside said drilling head, said piston members each possessed of an inclined portion at the leading end thereof,
a pair of rollers disposed in contact with the inclined portions of said pair of piston members, said pair of rollers being disposed on the lateral sides of the drilling head opposite each other across the axis of said drilling head at positions separated by a prescribed distance and said rollers being freely protrusibly drawn in below the surrounding surface of the drilling head, and
means for delivering compressed fluid to the cylinder means.

3 more elements

Dependencies are inferred from the claim text.