Patents by Inventor Dave C. Andrews

Dave C. Andrews has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Hydraulic interlock system between casing gripper and spider
    Patent number: 8439121
    Abstract: A system for deploying a string of pipe from a drilling rig into a well includes a spider for mounting on a rig floor and a pipe gripper attached to the top drive. A hydraulic safety circuit monitors hydraulic fluid pressure at an apply port of the gripper and prevents hydraulic fluid pressure from being directed to move the slips to the released position if hydraulic fluid pressure is not already present at the apply port of the gripper. The safety circuit also monitors hydraulic fluid pressure at the apply port of the spider and prevents release hydraulic fluid pressure from being directed to move the gripping members to the released position if apply hydraulic fluid pressure is not already present at the apply port of the spider.
    Type: Grant
    Filed: April 21, 2010
    Date of Patent: May 14, 2013
    Assignee: Tesco Corporation
    Inventors: Kevin J. Nikiforuk, Dave C. Andrews
  • Hydraulic Interlock System Between Casing Gripper and Spider
    Publication number: 20110114308
    Abstract: A system for deploying a string of pipe from a drilling rig into a well includes a spider for mounting on a rig floor and a pipe gripper attached to the top drive. A hydraulic safety circuit monitors hydraulic fluid pressure at an apply port of the gripper and prevents hydraulic fluid pressure from being directed to move the slips to the released position if hydraulic fluid pressure is not already present at the apply port of the gripper. The safety circuit also monitors hydraulic fluid pressure at the apply port of the spider and prevents release hydraulic fluid pressure from being directed to move the gripping members to the released position if apply hydraulic fluid pressure is not already present at the apply port of the spider.
    Type: Application
    Filed: April 21, 2010
    Publication date: May 19, 2011
    Applicant: Tesco Corporation
    Inventors: Kevin J. Nikiforuk, Dave C. Andrews