Patents by Inventor Mark E. Zirbel

Mark E. Zirbel 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: 8910434
    Abstract: Pre-cast concrete stairs, molds for making pre-cast concrete stairs, and methods of casting pre-cast concrete stairs are provided. The stair is constructed with two beams that are cast with the stair steps as an integral monolithic structure. One of the beams (integral down edge beam) projects below the steps on one side, and the other (integral up edge beam) projects above the steps on the other side. The weight of the stairs and the weight of traffic on the steps creates compression on the tops of the integral down edge beam and integral up edge beam, and tension on the bottoms of the integral down edge beam and integral up edge beam, which enhances the combined strength of the beams. The asymmetric orientation of the members creates a stronger cross-section than if the beams were in the same plane horizontally, allowing greater load handing capability. Lightweight steps are suspended between the two beams.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: December 16, 2014
    Assignee: Metromont Corporation
    Inventors: Mark E. Zirbel, Bryant A. Zavitz
  • Publication number: 20080115429
    Abstract: Pre-cast concrete stairs, molds for making pre-cast concrete stairs, and methods of casting pre-cast concrete stairs are provided. The stair is constructed with two beams that are cast with the stair steps as an integral monolithic structure. One of the beams (integral down edge beam) projects below the steps on one side, and the other (integral up edge beam) projects above the steps on the other side. The weight of the stairs and the weight of traffic on the steps creates compression on the tops of the integral down edge beam and integral up edge beam, and tension on the bottoms of the integral down edge beam and integral up edge beam, which enhances the combined strength of the beams. The asymmetric orientation of the members creates a stronger cross-section than if the beams were in the same plane horizontally, allowing greater load handing capability. Lightweight steps are suspended between the two beams.
    Type: Application
    Filed: November 21, 2007
    Publication date: May 22, 2008
    Applicant: ZMZ PRECAST INC.
    Inventors: Mark E. Zirbel, Bryant A. Zavitz