HYDRAULIC CLAMP FOR ROTARY DRILLING HEAD

摘要

A rotary drilling head having an upper body incorporating a kelly bushing removably clamped onto a stationary spool. The clamp assembly is hydraulically controlled to permit remote operation and access to the drive bearings and stripper rubbers within the drilling head. Secondary manual means for unclamping the assembly are also provided. The hydraulic clamp includes an annular piston movably disposed within a cylinder and acting upon bearing members to lock and unlock the clamp assembly. Hydraulic pressure is utilized to move the piston within the cylinder. A spring biases the piston towards the locked position to prevent inadvertent unclamping.