Thomas R Barr

43735940, Feb 15, 1983

Aug 10, 1981

6/291759

Thomas R. Barr - Denison TX

E21B 1060

175393

Described is a rotary drill bit comprising a hollow body having a closed lower end and means on the upper end for securing the body to the lower end of a drill string. The body is provided with a plurality of flow passages and a deflecting means is provided to deflect upwardly and away from the flow passages cuttings and the like to avoid plugging the passages during drilling while permitting unimpeded flow from the passages of all the fluid passing through the hollow body.

43802710, Apr 19, 1983

Apr 17, 1981

6/255129

Donald R. Baker - Denison TX
Thomas R. Barr - Denison TX
Paul C. Smith - Denison TX

Blue Streak Industries, Inc. - Denison TX

E21B 1044

175391

An auger system is described having an upstanding axial stem with a pilot bit attached to the bottom of the stem. A downwardly spiraling flight structure affixed to the axial stem has a leading edge terminating in the vicinity of the pilot bit. Enhanced cutting operations are provided by way of a cutting tooth holder structure removably secured to the leading edge of the flight structure and extending from a position adjacent the stem above the pilot bit to a position proximate to the perimeter of the flight structure. The holder structure is provided with a plurality of spaced apart pockets for receiving shank portions of cutting teeth. Stresses applied to the cutting teeth during operations are distributed through the holder structure back to the flight structure by way of reinforcing webs which extend from a position proximate to each of the cutting tooth receiving pockets to a position for contact with the leading edge of the flight structure. An improved rock cutting tooth is described having a principle cutting segment and a second segment which provides for reduced wear of the body of the tooth adjacent the first or principle cutting segment in order to reduce wear and thereby prevent the first cutting segment from breaking loose during cutting operation by reason of rapid erosion of the body portion.