Patents by Inventor Llewellyn Johnston

Llewellyn Johnston 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).

  • Publication number: 20070262229
    Abstract: A mold for concrete products includes a grid with a plurality of cavities that are open to both sides of the grid. The grid is bonded with polyurethane about its perimeter to the inner perimeter of a frame having a central opening therein. The grid may be formed of a single unitary piece or it may be formed from a plurality of sub-grids that are each bonded to the other with polyurethane.
    Type: Application
    Filed: May 8, 2007
    Publication date: November 15, 2007
    Applicant: COLUMBIA MACHINE, INC.
    Inventors: Douglas High, Stacy Gildersleeve, Llewellyn Johnston
  • Publication number: 20060182840
    Abstract: A concrete products forming machine including a main frame, feed drawers, die supports and mold and head assemblies. The feed drawer is moved into position over the mold using an electric belt drive system and includes a vibrating strike off plate to improve surface quality of the molded product, zoned agitators to control movement and placement of concrete, a spring loaded seal system between the walls and floor of the feed box, and quick-release agitator design with urethane sleeves to effect easy and clean removal, replacement and cleaning of the agitators. The concrete products forming machine includes torque tube and leaf spring supports to effect substantially vertical vibrational movement of the mold with air inflatable springs for controlled force between the mold bottom and the pallet. The pallet itself is vibrated from below using phased, counter rotating shafts coupled to the pallet table on which the pallet rests.
    Type: Application
    Filed: January 27, 2006
    Publication date: August 17, 2006
    Applicant: Columbia Machine, Inc.
    Inventors: Douglas High, Stacy Gildersleeve, Daniel Wahlstrom, Llewellyn Johnston, Keith Brewer
  • Publication number: 20050108973
    Abstract: A wall block comprises an upper surface spaced apart from a substantially parallel lower surface, opposed first and second faces, and opposed side surfaces converging between respective ends of the first and second faces. Blocks in a wall may be stacked on top of each other in either a vertical, set forward or set backward relationship. A three-block system for constructing walls includes a small, medium, and large block, each having two differently sized faces that can serve as the exposed face on one side of a wall. The small, medium, and large blocks can be manufactured using a single mold that is configured to provide a roughened texture resembling natural stone on two opposing faces of each block.
    Type: Application
    Filed: August 31, 2004
    Publication date: May 26, 2005
    Inventors: James Hammer, Llewellyn Johnston