Patents by Inventor Niels Hjarno Knudsen

Niels Hjarno Knudsen 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).

  • Casting machine for making concrete slabs
    Patent number: 4005971
    Abstract: A casting machine for making concrete slabs having a mold swingable about a horizontal axis and a vibrator swingable in a horizontal plane adjustable in height about a vertical axis from an inactive position at the side of the machine and into a working position above the mold. The vibrator is provided with a pressure plate for vibrating, compacting and glazing the surface of the concrete inside the mold, the bottom of which can be adjusted in vertical direction for producing slabs having different thicknesses. Further, the bottom is slidable from a filling position to a stripping position when the mold is turned 180.degree. about a horizontal axis.
    Type: Grant
    Filed: February 5, 1975
    Date of Patent: February 1, 1977
    Assignee: N. Hjarno Knudsen A/S
    Inventor: Niels Hjarno Knudsen