Patents by Inventor John Craig Holbert

John Craig Holbert 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).

  • Kiln and kiln-related structures, and associated methods
    Patent number: 6652274
    Abstract: Fans circulate heated air which is introduced from nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. The fans operate in first and second modes to respectively force flow in opposite first and second directions. Heated air is introduced from the nozzles at the high-pressure sides of the fans.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: November 25, 2003
    Inventors: Robert T. Nagel, John Craig Holbert
  • Kiln and kiln-related structures, and associated methods
    Publication number: 20030029052
    Abstract: Fans circulate heated air which is introduced from nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. The fans operate in first and second modes to respectively force flow in opposite first and second directions. Heated air is introduced from the nozzles at the high-pressure sides of the fans.
    Type: Application
    Filed: September 24, 2002
    Publication date: February 13, 2003
    Applicant: George R. Culp
    Inventors: Robert T. Nagel, John Craig Holbert
  • Drying kiln
    Patent number: 6467190
    Abstract: A duct system includes an upper duct that supplies heated air to an upper plenum and a lower duct that supplies heated air to a lower plenum, and the upper and lower plenums provide the heated air to a kiln chamber. An intermediate plenum is between the upper and lower plenums and has outlets through which heated air supplied to the upper and lower plenums is discharged. A plurality of circulation passages extend generally laterally through the intermediate plenum. Fans positioned in the circulation passages circulate heated air that is external to the plenums. The outlets are nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. Tips of the fans' blades extend into boundary layers adjacent the interior surfaces of the circulation passages. The fans operate in first and second modes to respectively force flow in opposite first and second directions.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: October 22, 2002
    Inventors: Robert T. Nagel, John Craig Holbert
  • DRYING KILN
    Publication number: 20020108266
    Abstract: A duct system includes an upper duct that supplies heated air to an upper plenum and a lower duct that supplies heated air to a lower plenum, and the upper and lower plenums provide the heated air to a kiln chamber. An intermediate plenum is between the upper and lower plenums and has outlets through which heated air supplied to the upper and lower plenums is discharged. A plurality of circulation passages extend generally laterally through the intermediate plenum. Fans positioned in the circulation passages circulate heated air that is external to the plenums. The outlets are nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. Tips of the fans' blades extend into boundary layers adjacent the interior surfaces of the circulation passages. The fans operate in first and second modes to respectively force flow in opposite first and second directions.
    Type: Application
    Filed: March 22, 2000
    Publication date: August 15, 2002
    Inventors: Robert T. Nagel, John Craig Holbert