Joint for use in back reaming

摘要

A joint according to the invention for connecting a pair of members rotatable about a common axis end to end. A sleeve has a non circular profile on an inner surface thereof whereby the sleeve can be slidably mounted on non circular exterior surfaces of the first and second members when such surfaces are brought into alignment by rotation of one member relative to the other in a manner effective to pass torque from one member to the other by means of the non circular surfaces. A fluid release passage includes a radial port that extends from the first longitudinal fluid supply passage to a clearance between the sleeve and the first member, which clearance communicates with a second clearance between the sleeve and the second member, which second clearance has a discharge opening.