Patents by Inventor William J. Engstrom

William J. Engstrom 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: 4193459
    Abstract: A vehicle-supported post-hole driver comprises a frame adapted to be mounted on the pivot of the vehicle drawbar. It is supported in a fore-and-aft position by a fluid cylinder connected between the frame and the support vehicle, the fluid cylinder providing for fore-and-aft movement of the outboard end of the frame. A second fluid cylinder pivots the frame about the drawbar pivot thereby transversely positioning the outboard end of the frame. The outboard end of the frame supports a pivotally-mounted yoke into which a pivotally-mounted vertical guide bearing is positioned. The combination of the pivoted yoke and the pivoted guide bearing provides a gimbaled arrangement. Slideably positioned in the guide bearing is a vertical shaft to which is attached a drive hammer and post-hole bit assembly. The drive hammer is raised relative to the post-hole bit by means of a fluid cylinder mounted within the bit and connected to the drive hammer. It drops gravitationally and drives the bit into the ground.
    Type: Grant
    Filed: March 7, 1978
    Date of Patent: March 18, 1980
    Inventor: William J. Engstrom
  • Patent number: 4008026
    Abstract: A mold and associated apparatus for the vertical forming of concrete fence posts. The mold has integral sides which are not opened for removal of the finished post. The apparatus provides a track and mold support means for a continuous casting operation.
    Type: Grant
    Filed: April 25, 1975
    Date of Patent: February 15, 1977
    Inventor: William J. Engstrom