The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1991
Filed:
Nov. 14, 1989
Thomas F Bailey, Houston, TX (US);
John E Campbell, Houston, TX (US);
MASX Energy Services Group, Inc., Houston, TX (US);
Abstract
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.