US 5,957,222 AGranted

Directional drilling system

AssigneeCharles T. Webb

InventorsCharles T. Webb, Roy L. Chandler

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Abstract

The apparatus, in one embodiment has a front shaft support and a guide housing coupled together for longitudinal movement relative to each other. A shaft extends through the front shaft support and the guide housing and has a drill bit coupled to its forward end. The shaft and front shaft support may be moved to a forward drilling position or to a rearward shifting position relative to the guide housing. A plurality of cams are coupled to the inside of the guide housing at different angular positions around the shaft. A cam follower is coupled to a cam follower housing which surrounds the shaft. In the shifting mode, the cam follower is disengaged from the cams. A clutch is provided for coupling the cam follower housing to the shaft when the shaft is in the shifting position such that the cam follower housing and the cam follower may be rotated with the shaft relative to the cams to allowed the cam follower to engage a selected one of the cams when the shaft is moved to the forward drilling position. In the forward drilling position of the shaft, the clutch releases the cam follower housing from the shaft and the cam follower engages the selected cam to allow straight drilling to occur or to cause the axis of said guide housing to shift relative to the axis of the shaft to cause the direction of drilling by the shaft and drill bit to change.

Claims33

Dependent claims

An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,
a shaft extending through said guide housing,
said shaft having a central axis and a forward end,
cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,
said shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,
cam means coupled to said guide housing at different angular positions around said shaft,
a cam follower coupled to a cam follower housing which surrounds said shaft,
said cam follower being disengaged from said cam means when said shaft is in said shifting position,
said cam follower housing and said cam follower being rotatable together relative to said guide housing when said shaft is in said shifting position,
said cam follower being movable longitudinally with said shaft relative to said cam follower housing and relative to said cam means,
a clutch for coupling said cam follower housing to said shaft when said shaft is in said shifting position such that said cam follower housing and hence said cam follower may be rotated with said shaft relative to said cam means to allow said cam follower to engage said cam means at a selected angular position around said shaft when said shaft is moved to said forward drilling position,
when said shaft moves toward said forward drilling position said clutch allows said cam follower housing to be uncoupled from said shaft such that in said forward drilling position of said shaft, said cam follower engages said cam means and causes said axis of said guide housing to shift relative to said axis of said shaft to cause the direction of drilling by said shaft and said cutting means to change.

9 more elements

An apparatus for drilling a hole in the earth, comprising:

a guide housing having a given axis,
a shaft extending through said guide housing,
said shaft having a central axis and a forward end,
cutting means coupled to said forward end of said shaft for drilling purposes, upon rotation of said shaft,
said shaft being movable longitudinally relative to said guide housing such that said shaft may be movable to a forward drilling position relative to said guide housing and to a rearward shifting position relative to said guide housing,
means located in said guide housing and controllable by movement of said shaft in said shifting position for locating said axis of said guide housing in at least first and second positions relative to said axis of said shaft,
in said first position, said axis of said housing generally coincides with said axis of said shaft to allow said apparatus to drill straight,
in said second position, said axis of said guide housing is shifted relative to said axis of said shaft to cause the direction of said apparatus to turn while drilling operations are carried out,
in said first and second positions of said guide housing relative to said axis of said shaft, said shaft is rotatable relative to said guide housing.

6 more elements

Dependencies are inferred from the claim text.