Patents by Inventor Allyn R. Pratt

Allyn R. Pratt 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).

  • Patent number: 4557327
    Abstract: A roller arm centralizer to center a drill string in a well pipe. The arms of the roller arm centralizer include shoulders to limit movement of the arms in the direction of the centralizer body which prevents the arms from being locked in a straight line adjacent to the centralizer body. The shoulders also prevent the arms from being forced into an undesired configuration; wherein one arm is parallel to the body and the other two arms form a "V", by an abrupt decrease in the bore diameter. The roller arm centralizer remains operative when passing through relatively narrow sections of well pipe or through well pipe having abrupt changes in diameter.
    Type: Grant
    Filed: September 12, 1983
    Date of Patent: December 10, 1985
    Assignee: J. C. Kinley Company
    Inventors: Karl S. Kinley, Allyn R. Pratt