Importance

Loading Importance Indicators...

Abstract

An earth boring bit particularly for use in drilling mining blast holes, has features for reducing the possibility of cutter drag and reducing wear on the bit legs. The bit is of the type having three bit legs, a bearing pin depending from each bit leg, and a cutter with a central cavity mounted on each bearing pin with roller bearings. The roller race for the roller bearings is formed in the central cavity of the cutter. The lower side of each bearing pin commences at the outer side of each bit leg, eliminating the shirttail flange. Clearances are provided between the central cavity and the bearing pin at the backface for the discharge of air in a direction parallel with the bearing pin axis.

Loading the Abstract Image...

First Claim