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:
Apr. 28, 1981
Filed:
Oct. 09, 1979
Joe R Brown, Houston, TX (US);
Brown Oil Tools, Inc., Houston, TX (US);
Abstract
An inside blowout preventer assembly for connection into an earth boring drill string has improved features for preventing erosion. The blowout preventer assembly allows downward flow during normal drilling, but prevents upward flow if the flow rate is above a selected amount, to prevent a blowout. The assembly includes a valve body with a longitudinal passage having a throat section. A recess passage intersects the throat section and contains a ball. The ball is movable from the recess passage into the throat section, where it seals against a seat to stop upward flow. An equalizing passage of selected size and configuration extends from the base of the recess passage to the longitudinal passage. The ball is of lesser diameter than the recess passage for allowing downward flow through the recess passage and the equalizing passage. This prevents the ball from being drawn by pressure differential into the throat section during downward flow, reducing turbulence and erosion.