All about central hydraulic

This invention pertains to drill rod handling means, and in particular to a device, fluid-powdered, which central hydraulic drill rods, when mounted on a drilling machine feed guide structure.
Fluid-powered drill rod centralizers are known, and usually comprise hydraulic- or pneumatic-actuated arms which abuttingly close upon one another and cooperate to define an aperture therebetween in which to centralize the drill rod. The known centralizers, then, have a single operative positioning, and lack any facility for restraining a drill rod coupling while simultaneously providing " centralizing" for a drill rod coupled to, or couplable with, the restrained coupling.
It is an object of this invention to provide a centralizer for drill rods which will provide for remote operation.