| 摘要 |
A rotary cone drill bit (20) for forming a borehole (24) having a one-piece bit body (40) with a lower portion (46) having a convex exterior surface and an upper portion (42) adapted for connection to a drill string (22). A number of support arms (70) are preferably attached to the bit body (40) and depend therefrom. Each support arm (70) has an inside surface (76) with a spindle (82) connected to the associated support arm (70). A number of cone cutter assemblies (100) equal to the number of support arms (70) are mounted on each of the spindles (82). The support arms (70) are spaced on the exterior of the bit body (40) to provide enhanced fluid flow between the lower portion (46) of the bit body and the support arms (70). Also, the length of the support arms (70) is selected to provide fluid flow between the associated cutter cone assembly (100) and the lower portion (46) of the bit body. The same bit body may be used with various rotary cone drill bits having different gauge diameters.
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