摘要 |
Hydraulic flow may be rendered substantially uniform throughout the waterways on a rotating bit from the center of the bit to the cuter gage. This is accomplished by defining waterways into the bit face below a primary surface of the bit face. A colinear land is then disposed into the waterway, but does not extend above the primary surface of the bit face. A plurality of teeth are then disposed on the colinear land and extend above the primary surface of the bit face. The flow of hydraulic fluid is prevented from dispersing as the fluid moves from the center of the bit to the outer gage. Cutting by kerfing is further optimized by arranging triads of cutters on each of the pads disposed in the waterways into a set. Each triad of cutters corresponds to additional triads of cutters in azimuthally subsequent and adjacent pads in the next subsequent waterway, thereby forming the set of associated triads of cutters. Each triad of cutters in the set is radially offset from the corresponding triads in the set. Therefore, while each triad cuts through a kerfing action individually, each triad relates to the preceding triad of cutters to cut into the kerfed lands made by that preceding triad of cutters and thus to cut through a kerfing action as well. |