Patents by Inventor Richard R. Koehn

Richard R. Koehn 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).

  • Strand chair for supporting prestressing cable and cross-mesh in elongated precast concrete plank
    Patent number: 4644727
    Abstract: The chairs include a lower chair portion for supporting multiple prestressing cables at the bottom of a plank and a narrow upper chair portion for supporting an upper prestressing cable located in the web between the hollow cores of the prestressed plank. The upper chair portion can be inserted into the strand receiving cups of the lower portion to form a structurally sound support for accurately placing the top and bottom reinforcing strands in the plank as it is cast.
    Type: Grant
    Filed: February 4, 1986
    Date of Patent: February 24, 1987
    Assignee: Fabcon, Inc.
    Inventors: David W. Hanson, Richard R. Koehn, Richard C. Nash, Lonnie G. Fox
  • Machine for casting concrete members
    Patent number: 4457682
    Abstract: A machine for casting concrete panels. The machine disclosed casts hollow core concrete panels in a single casting operation utilizing a slipform technique to fill cores with core material which can be dumped from the core after curing of the concrete has been accomplished. Vibration of the slipform during casting facilitates free flow of concrete around the slipform and core material extruded from slipforms. The slipfom has a closed front portion which is tapered to a reduced cross section. The machine utilizes a casting pallet employing improved side form cleaning apparatus. The machine also includes improved finishing screeds for applying decorative three-dimensional finishes on the top surface of cast panels.
    Type: Grant
    Filed: January 14, 1983
    Date of Patent: July 3, 1984
    Assignee: Fabcon, Inc.
    Inventors: Richard C. Nash, David W. Hanson, Richard R. Koehn
  • Device for lifting and tilting concrete panels
    Patent number: 4398761
    Abstract: A device for both lifting and dumping of core material from long hollow core concrete panels. The device utilizes a pair of retractable clamp members to engage the longitudinal groove in the side of the panel.
    Type: Grant
    Filed: August 3, 1981
    Date of Patent: August 16, 1983
    Assignee: Fabcon, Incorporated
    Inventors: David W. Hanson, Richard C. Nash, Richard R. Koehn
  • Machine for casting concrete members
    Patent number: 4369153
    Abstract: A machine for casting concrete panels. The machine disclosed casts hollow core concrete panels in a single casting operation utilizing a slipform technique to fill cores with core material which can be dumped from the core after curing of the concrete has been accomplished. Vibration of the slipform during casting facilitates free flow of concrete around the slipform and core material extruded from slipforms. The slipform has a closed front portion which is tapered to a reduced cross section. The machine utilizes a casting pallet employing improved side form cleaning apparatus. The machine also includes improved finishing screeds for applying decorative three-dimensional finishes on the top surface of cast panels.
    Type: Grant
    Filed: April 27, 1981
    Date of Patent: January 18, 1983
    Assignee: Fabcon, Inc.
    Inventors: Richard C. Nash, David W. Hanson, Richard R. Koehn
  • Combination lift insert and weld plate for use in hollow core concrete planks
    Patent number: D272517
    Type: Grant
    Filed: June 15, 1981
    Date of Patent: February 7, 1984
    Assignee: Fabcon, Inc.
    Inventor: Richard R. Koehn