Patents Examined by John N Fristoe, Jr.
  • Wiper seal assembly
    Patent number: 8403290
    Abstract: A hydraulically-operated annular blowout preventer, for controlling a wellbore and comprising a wiper seal assembly, is described. The wiper seal assembly comprises a discrete wiper seal, for preventing debris and/or contaminants from the wellbore from entering the hydraulic fluid chamber of the blowout preventer, a discrete pressure seal, positioned below and abutting the wiper seal in the same seal groove, for isolating the hydraulic chamber, and a retainer member for preventing both radial and axial movement of the wiper seal.
    Type: Grant
    Filed: June 9, 2008
    Date of Patent: March 26, 2013
    Assignee: Alberta Petroleum Industries Ltd.
    Inventors: Scott Delbridge, Dean Foote