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:
Sep. 14, 2010
Filed:
Jul. 21, 2008
Applicant:
Kevin J. Nikiforuk, Houston, TX (US);
Inventor:
Kevin J. Nikiforuk, Houston, TX (US);
Assignee:
Tesco Corporation, Houston, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 34/16 (2006.01);
U.S. Cl.
CPC ...
Abstract
A safety valve has a body with a passage extending through it that intersected by a chamber and inclined guide surfaces located in the chamber. A single slab gate with an aperture has ramp surfaces on one side. When moving from the open position to the closed position, the ramp surfaces slide onto the guide surfaces and push the gate into sealing engagement with a side of the chamber to block the passage. The safety valve is particularly useful during a casing-while-drilling operation wherein it is mounted to the upper end of the casing when the casing gripper and top drive are disconnected from the casing string.