CORE DRILLING LATCH ASSEMBLY

摘要

A core drilling latch assembly for use in terrestrial core drilling operatio ns. The latch assembly incorporates features and elements which affect the flow of drillin g fluids past the latch assembly and toward the drill bit, depending upon whether the latch as sembly has contacted the landing ring in the drill string and whether the latch assembl y has locked in place within the string. Accordingly, the latch assembly signals the drillin g crew by pressure fluctuations when the latch assembly is in proper position within the drill string, and whether it is locked in position.