US 2009/0260890 A1 · ANTI-TRACKING FEATURE FOR ROCK BITS

Abstract

The harmful effects of tracking are reduced for a drill bit having roller cones with at least one of the outermost rows of active teeth containing one or more teeth having a height that does not extend to the height of at least one of the outermost rows on another roller cone on the bit. The crest on this tooth may have a length in a circumferential direction that is wider than an overall width of the tooth in the outer to inner direction. The invention may be used on any cutter row, not just the outermost row. The design may be used on a different roller cone or row, or more than one cutter row. The anti-tracking feature may be located between the leading and trailing edges of the tooth on one or more roller cones.

Claims25

Dependent claims

A drill bit for reducing harmful effects of tracking, comprising:

a bit body having bit legs with bearing pins;
a roller cone mounted to each of the bearing pins to define a plurality of roller cones, each roller cone having an axis and rows of active teeth, each of the active teeth having a radial height, an outer end and an inner end that define a length, a pair of flanks that define a width and a crest at which the ends and flanks converge;
spaces between the active teeth that define a depth of cut for the roller cones;
and
an anti-tracking element on at least one of the rows of active teeth and having a second radial height that is less than the radial height of the active teeth and extending into a range of the depth of cut, such that the anti-tracking element engages and removes formation that remains as a result of uncut formation left behind by the active teeth.

2 more elements

Dependencies are inferred from the claim text.

Anti-tracking feature for rock bits

Life of this patent

Anti-tracking feature for rock bits

Life of this patent

Abstract

Claims25