Patents by Inventor Riki Takeshita

Riki Takeshita 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: 6213379
    Abstract: Friction plug welding (FPW) usage is advantageous for friction stir welding (FSW) hole close-outs and weld repairs in 2195 Al—Cu—Li fusion or friction stir welds. Current fusion welding methods of Al—Cu—Li have produced welds containing varied defects. These areas are found by non-destructive examination both after welding and after proof testing. Current techniques for repairing typically small (<0.25″) defects weaken the weldment, rely heavily on welders' skill, and are costly. Friction plug welding repairs increase strength, ductility and resistance to cracking over initial weld quality, without requiring much time or operator skill. Friction plug welding while pulling the plug is advantageous because all hardware for performing the weld can be placed on one side of the workpiece.
    Type: Grant
    Filed: August 26, 1998
    Date of Patent: April 10, 2001
    Assignee: Lockheed Martin Corporation
    Inventors: Riki Takeshita, Terry L. Hibbard