Patents by Inventor Llewellyn L. Johnston

Llewellyn L. 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).

  • Patent number: 10245756
    Abstract: A mold assembly for forming concrete products comprising a mold box having cavities for receiving and molding concrete products and a mounting bracket extension coupled to each side wall of the mold box and forming a lower mounting surface of the mold box. Die alignment holes are formed in an underside of each mounting bracket extension and are configured to receive alignment dowels extending upward from shelves of the concrete products forming machine on which the mold box sits. The mounting bracket extensions further include mold transfer locators formed on the underside inward of the die alignment holes so that they are exposed from below when the mold assembly sits on the shelves of the concrete products forming machine. These locators are configured to locate the mold assembly onto mold extractor arms when the mold assembly is lifted off of the alignment dowels by the mold extractor arms during a mold extraction process.
    Type: Grant
    Filed: January 8, 2016
    Date of Patent: April 2, 2019
    Assignee: COLUMBIA MACHINE, INC.
    Inventors: Llewellyn L. Johnston, Stacy L. Gildersleeve
  • Patent number: 10066300
    Abstract: A compression shoe for use on a concrete products forming machine comprises a main body and a plated layer overlaid on the main body. The main body is configured to be slidingly received within a mold cavity of a concrete products mold. The plated layer overlaid on the main body of the compression shoe comprises a uniform electroless nickel (Ni), phosphorus (P), and polytetrafluoroethylene (PTFE) nano dispersion coating to effect enhanced material release characteristics by preventing the build-up of material on the compression shoes and enhancing their wear characteristics.
    Type: Grant
    Filed: July 19, 2016
    Date of Patent: September 4, 2018
    Assignee: COLUMBIA MACHINE, INC.
    Inventor: Llewellyn L. Johnston
  • Publication number: 20180021979
    Abstract: A compression shoe for use on a concrete products forming machine comprises a main body and a plated layer overlaid on the main body. The main body is configured to be slidingly received within a mold cavity of a concrete products mold. The plated layer overlaid on the main body of the compression shoe comprises a uniform electroless nickel (Ni), phosphorus (P), and polytetrafluoroethylene (PTFE) nano dispersion coating to effect enhanced material release characteristics by preventing the build-up of material on the compression shoes and enhancing their wear characteristics.
    Type: Application
    Filed: July 19, 2016
    Publication date: January 25, 2018
    Inventor: Llewellyn L. Johnston
  • Publication number: 20170197331
    Abstract: A mold assembly for forming concrete products comprising a mold box having cavities for receiving and molding concrete products and a mounting bracket extension coupled to each side wall of the mold box and forming a lower mounting surface of the mold box. Die alignment holes are formed in an underside of each mounting bracket extension and are configured to receive alignment dowels extending upward from shelves of the concrete products forming machine on which the mold box sits. The mounting bracket extensions further include mold transfer locators formed on the underside inward of the die alignment holes so that they are exposed from below when the mold assembly sits on the shelves of the concrete products forming machine. These locators are configured to locate the mold assembly onto mold extractor arms when the mold assembly is lifted off of the alignment dowels by the mold extractor arms during a mold extraction process.
    Type: Application
    Filed: January 8, 2016
    Publication date: July 13, 2017
    Inventor: Llewellyn L. Johnston
  • Patent number: 6007321
    Abstract: A unitary concrete product mold formed from a central member having an array of product-shaping molds bounded by side and end portions. Support rails mounted on the bottom surface of the central member limit deflection of the central portion of the central member, improving product quality and reducing mold wear.
    Type: Grant
    Filed: January 15, 1998
    Date of Patent: December 28, 1999
    Inventors: Kevin Meckel, Alan L. Hoskins, Kevin T. Litterell, Ronald J. Rowland, Brendan D. Scully, Llewellyn L. Johnston
  • Patent number: 5939104
    Abstract: A mold box assembly includes a rectangular mold box frame having a substantially vertical divider plate mounted on the frame and extended part-way into it from an the upper side of the frame. A pair of rectangular restrictor plates are disposed vertically in the mold box from side to side and extend to the same depth as the divider plate. Wet product mix is dropped onto the box and is thereafter compressed with a shoe assembly. The shoe assembly includes a pair of shoes that extend from one side of the mold box to the other and have a thickness that allows them to be interleaved with the restrictor plates. The shoes are lowered to the lower edge of the restrictor plates. Simultaneously, another shoe mounted on the head plate compresses product on the other side of the divider plate so a higher level thus forming a header block having a first lower height formed beneath the restrictor plates and a second higher height formed on the other side of the divider plate.
    Type: Grant
    Filed: February 11, 1998
    Date of Patent: August 17, 1999
    Assignee: Columbia Machine, Inc.
    Inventor: Llewellyn L. Johnston
  • Patent number: 5866026
    Abstract: A adjustable mold box assembly for forming molded concrete products includes a pair of opposed substantially parallel end plates joined at both ends by a pair of opposed substantially parallel mounting brackets. A selected plurality of partition plates extend between the end plates to define a plurality of cavities for forming molded products in accordance with the number and dimension of molded products desired. A slot is formed along the inside of each end plate substantially along the length thereof. Tabs which extend from opposing ends of each partition plate include a stud transversely mounted on the end plate using ring nuts. The opposing tabs and studs of each end plate are received in opposing end plate slots. End liners are bolted to the inside surface of each end plate over the studs on each side of each partition plate with the ring nuts bearing against the surface of the end liner.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: February 2, 1999
    Assignee: Columbia Machine, Inc.
    Inventor: Llewellyn L. Johnston
  • Patent number: 5743510
    Abstract: A mold box for molding concrete products includes a pair of opposed substantially parallel end plates. A pair of opposed substantially parallel mounting brackets are positioned at opposite ends of the end plates and together with the end plates form a substantially rectangular mold box. A corner portion is defined adjacent the juncture of each mounting bracket with each end plate. At least one partition plate extends from one end plate to the other between the mounting brackets. An alignment pin is formed on the mounting bracket at each corner portion and an alignment bore coaxial with the pin is formed on the end plate. The bores are sized and positioned so that when each bore has its associated alignment pin therein the mold box assembly is sufficiently aligned to form molded products.
    Type: Grant
    Filed: December 21, 1994
    Date of Patent: April 28, 1998
    Assignee: Columbia Machine
    Inventor: Llewellyn L. Johnston
  • Patent number: 5648009
    Abstract: An apparatus for mounting a mold box on a machine for forming molded concrete products includes a mold defining a cavity for receiving cement having a pair of opposed side plates and a pair of opposed mounting brackets. A mold support frame is further included having a pair of opposed side beams and a pair of opposed end brackets, with a connecting device for mounting the support frame on the machine. A pair of opposed substantially parallel slots is formed on the support frame side beams and a sliding plate is receivable in the slots and slidable therealong. A slot is also formed on one of the mold mounting brackets, such that the sliding plate is receivable in the slot formed on the mold mounting bracket.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: July 15, 1997
    Assignee: Columbia Machine, Inc.
    Inventor: Llewellyn L. Johnston
  • Patent number: 5542837
    Abstract: A mold box assembly for forming molded concrete products includes a pair of opposed substantially parallel end plates joined at both ends by a pair of opposed substantially parallel mounting brackets. A plurality of partition plates extend between the end plates to define a plurality of substantially identical cavities for forming molded products. A slot is formed along the inside of each end plate substantially along the length thereof. Tabs which extend from opposing ends of each partition plate include a stud transversely mounted on the end plate using ring nuts. The opposing tabs and studs of each end plate are received in opposing end plate slots. End liners are bolted to the inside surface of each end plate over the studs on each side of each partition plate with the ring nuts bearing against the surface of the end liner.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: August 6, 1996
    Assignee: Columbia Machine, Inc.
    Inventor: Llewellyn L. Johnston