Patents by Inventor Patrick R. Callihan

Patrick R. Callihan 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).

  • Power tong and back-up tong assembly
    Patent number: 4445402
    Abstract: A power tong and back-up tong assembly is comprised of a power tong having a rotatable cam surface which cooperates with jaw assemblies to grip and rotate a first pipe and a back-up tong having a fixed cam ring and jaw assemblies which are rotated against the cam ring in the same direction as the cam surface of the power tong rotates until an initial grip is achieved on a second pipe which is to be held while the first pipe is threaded or unthreaded relative thereto.
    Type: Grant
    Filed: February 25, 1982
    Date of Patent: May 1, 1984
    Assignee: Farr Oil Tool, Inc.
    Inventors: Garth M. Farr, Patrick R. Callihan