Drill tube drive mechanism - applying spring loaded jaws in box section guides by wedges on ring acting on barrel shaped rollers

摘要

A drive mechanism for drill pipes and casings consists of a revolving chuch in which several box-section clamping jaws can be moved radially against the force of a spring. The jaws move in radial guide housings and carry on the outside a barrel-shaped roller. Wedges on a ring which surrounds the chuck and revolves with it, can be moved relative to the barrel-shaped rollers by power rams which act on an outer ring resting through a radial ball bearing. This is a simple design which can be fabricated by flame cutting and welding and requires little machining. It is easy to service without dismantling and has a lesser weight and size than conventional drive mechanisms.