Connection for pipe joints

Claim 2

A threaded connection for joining pipe which comprises: a pin member having external threads formed thereon; a box member having internal threads formed therein; said pin and box members in an assembled relationship defining an annular cavity at the base of the said pin member; and a resilient seal ring mounted in said cavity; said pin member or said box member having means formed therein defining a flow passage extending from said cavity to the interior of said pipe and being adapted to conduct lubricant between said members away from said cavity only to the interior of said pipe and thereby prevent the buildup of pressure in said cavity as said pin and box members are screwed together.

Claim 3

A connection as defined in claim 1 wherein said passage includes at least one longitudinal groove extending transversely through the threads of said pin member.

Claim 4

A connection as defined in claim 2 wherein the width of said groove is not greater than about 0.5 radians.

Claim 5

A connection as defined in claim 1 wherein said flow passage includes a plurality of longitudinal grooves circumferentially spaced about said pin member and extending transversely through the threads thereof.

Claim 6

A connection as defined in claim 1 wherein said seal ring is an elastomeric seal ring.

Claim 7

A connection as defined in claim 1 wherein said seal ring is an elastomeric O-ring.

Claim 8

A tool joint for joining pipe sections of a rotary drill string which comprises: a pin member having an externally threaded pin, an axial surface at the base of said pin, and a radial shoulder extending outwardly from the base of said pin; a box member having internal threads adapted to mate with said pin threads, an axial internal surface formed in its outer end, and a radial shoulder extending outwardly from said axial surface, said radial shoulder of said box member being adapted to contact said radial shoulder of said pin member; said axial surface and radial shoulder of said pin member in combination with said axial surface of said box member defining an annular cavity with said shoulders contacting one another; a resilient seal ring mounted on said pin member within said cavity for sealing the interface of said contacting shoulders; and at least one longitudinal groove extending transversely through the threads of said pin member providing fluid communication from said cavity to the interior of said drill string.

Claim 9

A tool joint for joining pipe sections of a rotary drill string which comprises: a pin member having an externally threaded pin, an axial surface at the base of said pin, and a radial shoulder extending outwardly from the base of said pin; a box member having internal threads adapted to mate with said pin threads, an axial internal surface formed in its outer end, and a radial shoulder extending outwardly from said axial surface, said radial shoulder of said box member being adapted to contact said radial shoulder of said pin member; said axial surface and radial shoulder of said pin member in combination with said axial surface of said box member defining an annular cavity with said shoulders contacting one another; a resilient seal ring mounted on said pin member within said cavity for sealing the interface of said contacting shoulders; and at least one longitudinal groove extending transversely through the threads of said pin member providing fluid communication from said cavity to the interior of said drill string.

Claim 10

A tool joint as defined in claim 7 wherein said seal ring is an elastomeric O-ring.