Curnie A Dunn

US Patent:

6595305, Jul 22, 2003

Filed:

Jun 9, 2000

Appl. No.:

09/591644

Inventors:

Curnie A. Dunn - Bristol VA
Phillip W. Haga - Chilhowie VA
Ted R. Massa - Latrobe PA
Douglas E. Bise - Chilhowie VA
Gary J. Condon - Irwin PA
Stephen T. Belsheim - Kingston Springs TN
James E. Rutherford - Big Stone Gap VA

Assignee:

Kennametal Inc. - Latrobe PA

International Classification:

E21B 1038

US Classification:

1754201, 175336, 175418

Abstract:

A rotary drill bit for penetrating earth strata wherein the drill bit includes a drill bit body that has an axial forward end. The drill bit body has a hard insert, which is preferably monolithic, that is affixed to the drill bit body at the axial forward end thereof. The hard insert presents at least three discrete leading cutting edges for cutting the earth strata.