Patents Represented by Law Firm Seed, Berry, Vernon & Baynam
  • Hydraulic drilling rig and power swivel
    Patent number: RE29541
    Abstract: A two-ram hydraulic drilling rig is provided with a lateral support frame. The rams have rods connected through a tension structure with a power swivel. The power swivel has a removable swivel stem assembly for allowing through-swivel positioning of drill pipe, particularly for tripping.
    Type: Grant
    Filed: November 16, 1976
    Date of Patent: February 21, 1978
    Assignee: Western Gear Corporation
    Inventor: Duane K. Russell