Patents Assigned to James Walker Co., Ltd.
  • Rotary drill bit with lip seal in roller cone bit
    Patent number: 6357540
    Abstract: A roller-cone drill bit in which a double lip seal, made of a self-lubricating elastomer, protects the bearings from the mud.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: March 19, 2002
    Assignees: Halliburton Energy Services, Inc., James Walker Co., Ltd.
    Inventors: Nigel M. Page, Philip D. Embury