摘要 |
A drilling apparatus for earth boring operations is of the type having cutter blades mounted on a support body at the lower end of a drill string and includes a novel arrangement of fluid bore sections for delivering fluid under pressure into fluid discharge passages in each of the blades and a bifurcated pivotal mounting portion on the body which enables the bore sections to supply fluid to the cutter blades through a ball joint on the pivotal axis. Modified forms of invention are specifically designed for cutter blades which are intended to perform reaming operations but include the fluid delivery system as well as an extended delivery system for delivering fluid under pressure to other tools in the drill string.
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