دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n pl: on conventional rotary rigs and top-drive rigs, hinged steel devices with manual operating handles that crew members latch on to a tool joint (or a sub). Since the elevators are directly connected to the traveling block, or to the integrated traveling block in the top drive, when the driller raises or lowers the block or the topdrive unit, the drill pipe is also raised or lowered.

the snap-around latches that couple around tubing below the pipe coupling and enables the traveling block on a rig to gab and lift the tubular string.