| US 7,571,782 B2 | ||
| Stiffened blade for shear-type drill bit | ||
| David R. Hall, 2185 S. Larsen Pkwy., Provo, Utah 84606 (US); and John Bailey, 2185 S. Larsen Pkwy., Provo, Utah 84606 (US) | ||
| Filed on Jun. 22, 2007, as Appl. No. 11/767,044. | ||
| Prior Publication US 2008/0314645 A1, Dec. 25, 2008 | ||
| Int. Cl. E21B 10/36 (2006.01) | ||
| U.S. Cl. 175—432 [175/425] | 10 Claims |
| 1. A drill bit, comprising:
a steel body disposed intermediate a threaded end and a working face;
the steel body comprising a plurality of steel blades disposed along an outer diameter of the body and extending radially
away from an axis of rotation of the bit;
a plurality of cutter elements disposed on the plurality of steel blades;
the cutting elements each comprising a sintered body of diamond bonded to a cemented metal carbide substrate at a non-planar
interface;
the plurality of steel blades each comprising a steel stiffness and a steel elastic modulus;
at least one of the plurality of steel blades comprising a plurality of substantially cylindrical, carbide segments brazed
behind and substantially coaxial with the plurality of cutter elements and being brazed to the substrate of the cutting elements;
and
carbide backing plates are brazed to the back surface of the blade that forms part of the junk slot;
wherein the segments and backing plate together increase the stiffness of the blade by at least 3.5 times the steel stiffness.
|