Failure indicator for rolling cutter drill bit

Abstract

A bearing failure indicator for sealed and lubricated rolling cutter earth boring drill bits is disclosed. A plurality of cutting inserts, arranged in a plurality of rows, are secured in the rolling cone cutters. At least two of the rolling cone cutters are intermeshing cutters, arranged such that they have intermeshing rows of cutting inserts. A groove is formed in the intermeshing cutters with a row containing a plurality of generally flat top bearing inserts. In the normal operation of the drill bit, the rows of generally flat top bearing inserts do not contribute to the drilling action of the drill bit. However, when a bearing assembly fails in operation, the generally flat top bearing inserts engage the intermeshing rows of inserts in the adjacent intermeshing cutter causing the drilling torque to increase and thereby providing a signal indicating the bearing has failed.

Dependencies are inferred from the claim text.