Patents by Inventor R. Douglas Hudgens

R. Douglas Hudgens 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: 6953534
    Abstract: In general this invention relates to an antifreeze composition that can be used in the cooling systems of internal combustion engines, for example, in heavy-duty diesel engines, light duty trucks and cars. The antifreeze composition can be added to water or other suitable liquid coolant in the cooling system, to lower the freezing point temperature of the coolant and inhibit corrosion of metallic components associated with the cooling system. The antifreeze composition is particularly well suited, although not exclusively, for use with hard water. The antifreeze composition includes an organic acid component comprising adipic acid and at least one of benzoic acid and one or more C9-C12 dicarboxylic acid—or salts of these acids. The antifreeze composition also includes other anti-corrosive additive, for example, molybdate, nitrite, nitrate silicate azoles and a variety of buffer agents.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: October 11, 2005
    Assignee: Fleetguard, Inc.
    Inventor: R. Douglas Hudgens
  • Patent number: 6733687
    Abstract: In general, this invention relates to supplemental coolant additive for use in cooling systems, for example, in diesel engine cooling systems. The supplemental coolant additive includes a C4-C6 dicarboxylic acid, preferably adipic acid, and optionally a C9-C12 aliphatic dicarboxylic acid an aromatic monocarboxylic acid, an aromatic dicarboxylic acid and salts of these acids. The supplemental coolant additive also can include a variety of other additives including molybdate salts, nitrate salts, nitrite salts, silicate salts and buffering agents. The supplemental coolant additive is preferably provided as a solid additive or a liquid concentrate. The supplemental coolant additive is preferably added to the liquid coolant over time to provide increased coolant life. Further the supplemental coolant additive provides enhanced anti-corrosion protection in cooling systems that include hard water.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: May 11, 2004
    Assignee: Fleetguard, Inc.
    Inventor: R. Douglas Hudgens
  • Patent number: 5772873
    Abstract: A coolant filter for use in filtering a coolant solution which flows through the coolant filter includes a filter housing assembly which is made up of an outer housing which is crimped to a nutplate which defines an internally threaded flow outlet. A generally cylindrical filter element is positioned inside of the filter housing assembly and a first endplate is bonded to the end of the filter element which is adjacent to the nutplate. A second endplate is bonded to the opposite end of the filter element and helps to define an interior space within the filter element. A supply of supplemental coolant additive is contained within an osmotic film enclosure which is positioned within the interior space. The osmotic film enclosure provides a slow release mechanism for controlling the rate of release of the supplemental coolant additive into the coolant solution. In one embodiment of the present invention, the slow release mechanism includes a diffusion tube which defines a diffusion orifice.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: June 30, 1998
    Assignee: Fleetguard, Inc.
    Inventors: R. Douglas Hudgens, Charles L. Matheson
  • Patent number: 5662799
    Abstract: A coolant filter for use in filtering a coolant solution which flows through the coolant filter includes a filter housing assembly which is made up of an outer housing which is crimped to a nutplate which defines an internally threaded flow outlet. A generally cylindrical filter element is positioned inside of the filter housing assembly and a first endplate is bonded to the end of the filter element which is adjacent to the nutplate. An endplate member is provided for attachment to the opposite end of the filter element and is configured in such a way so as to define an interior chamber where supplemental coolant additive pellets are stored. A closing plate is applied across the open end of the interior chamber so as to create an enclosed chamber for the supplemental coolant additive pellets. A slow release mechanism is provided for controlling the rate of release of the supplemental coolant additive from the enclosed chamber into the coolant solution.
    Type: Grant
    Filed: June 21, 1996
    Date of Patent: September 2, 1997
    Assignee: Fleetguard, Inc.
    Inventors: R. Douglas Hudgens, Charles L. Matheson
  • Patent number: RE37369
    Abstract: A coolant filter for use in filtering a coolant solution which flows through the coolant filter includes a filter housing assembly which is made up of an outer housing which is crimped to a nutplate which defines an internally threaded flow outlet. A generally cylindrical filter element is positioned inside of the filter housing assembly and a first endplate is bonded to the end of the filter element which is adjacent to the nutplate. An endplate member is provided for attachment to the opposite end of the filter element and is configured in such a way so as to define an interior chamber where supplemental coolant additive pellets are stored. A closing plate is applied across the open end of the interior chamber so as to create an enclosed chamber for the supplemental coolant additive pellets. A slow release mechanism is provided for controlling the rate of release of the supplemental coolant additive from the enclosed chamber into the coolant solution.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: September 18, 2001
    Assignee: Fleetguard, Inc.
    Inventors: R. Douglas Hudgens, Charles L. Matheson