Patent ID: 7387167

Claim:
An electrically insulating sleeve for a downhole tool for electrically insulating a first threaded electrically conductive member from a second threaded electrically conductive member, the insulating sleeve having inner and outer surfaces defining respective first and second threads corresponding to the threads on the first and second electrically conductive members, respectively, for coupling the first and second electrically conductive members together, and the sleeve being shaped such that on coupling the first and second members together, longitudinally adjacent thread turns on said first and second members overlap in a radial direction, wherein the first and second threads of the insulating sleeve are generally box shaped in cross-section, and wherein the sleeve comprises a tapered sleeve including shoulders at opposite ends thereof, each shoulder adapted to abut the first and second members in use, and each shoulder further comprises first and second faces, each of the first and second faces disposed at an oblique angle with respect to a radius of the sleeve.