Earth-boring bit with improved cutting structure

摘要

An earth-boring bit has a bit body and at least one cutter rotatably secured to the bit body. The cutter has a cutter shell surface including a gage surface and a heel surface. A plurality of cutting elements inserts are arranged in generally circumferential rows on the cutter. At least one chisel-shaped cutting element is secured to the gage surface. The chisel-shaped cutting element has a pair of surfaces converging to define a circumferential crest and is tilted toward the heel surface such that a line drawn through the center of the cutting element and its crest defines an acute angle of between about 15 and 75 degrees with the gage surface of the cutter.