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:
Nov. 05, 1991
Filed:
Jul. 31, 1990
Thomas F Bailey, Houston, TX (US);
Larry F Moeller, Houston, TX (US);
MASX Energy Services Group, Inc., Houston, TX (US);
Abstract
A stripper rubber for use in a drilling head to seal against a work string deployable through the drilling head. The stripper rubber is longitudinally restrained to prevent extrusion of the stripper under pressure and to reduce the tensile and compressive stresses on the stripper rubber. One embodiment of the stripper rubber incorporates upper and lower metal rings which are maintained in spaced apart relation by vertical rods thereby allowing radial expansion as tool joints pass through the rubber but prevents inversion of the stripper rubber under pressure. Reinforcing cords added to the stripper rubber increase the longitudinal strength. A second embodiment bonds a stripper rubber into a cylinder which restrains the rubber in the vertical direction. Radial deflection is accomodated by allowing the rubber to flow vertically as a tool joint passes therethrough. Each of the stripper rubbers incorporates an integrally formed drive bushing which facilitates mounting within the drilling head.