Henry L Hebert

US Patent:

46253815, Dec 2, 1986

Filed:

Apr 24, 1981

Appl. No.:

6/257175

Inventors:

Francis Gravouia - Lafayette LA
Henry Hebert - Carencro LA

International Classification:

E21B 1712

US Classification:

29283

Abstract:

An apparatus which provides for a sub-body having a mandrel with a longitudinal bore therethrough having a rigidly attached upper collar section for engagement onto a section of pipe or the like, and having a threadably removable lower collar section for threadably engaging the end of a second lower section of drill pipe. Insertable onto the mandrel or body section of the sub-unit is a retriever section, which is substantially circular in nature and slidably movable between the end collars of the sub-unit. The retriever section is adapted with protruding members, radially around its exterior most vertical wall for engaging with an extended J-slot of a wear bushing following the lowering of the retrieving unit into the bushing. Also provided is a pair grooved sections running substantially the length of the mandrel section of the sub-unit on both sides of the mandrel, wherein a intruding member on the retriever unit may move along the vertical body, but is disallowed for rotational movement thereupon. An alternate embodiment would include exterior threads for threadably engaging the wear bushing to be retrieved.