Patents by Inventor Dennis Lettkeman

Dennis Lettkeman 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: 10221100
    Abstract: The invention provides a pourable composition comprising calcium sulfate hemihydrate; optionally, cement; one or more anionic surfactants selected from alkyl anionic surfactants, alkyl ether anionic surfactants, alkyl aryl anionic surfactants, and combinations thereof; one or more set accelerator additives; and water.
    Type: Grant
    Filed: June 7, 2017
    Date of Patent: March 5, 2019
    Assignee: UNITED STATES GYPSUM COMPANY
    Inventors: Michael Intorcia, Dennis Lettkeman
  • Publication number: 20170349492
    Abstract: The invention provides a pourable composition comprising calcium sulfate hemihydrate; optionally, cement; one or more anionic surfactants selected from alkyl anionic surfactants, alkyl ether anionic surfactants, alkyl aryl anionic surfactants, and combinations thereof; one or more set accelerator additives; and water.
    Type: Application
    Filed: June 7, 2017
    Publication date: December 7, 2017
    Applicant: UNITED STATES GYPSUM COMPANY
    Inventors: Michael Intorcia, Dennis Lettkeman
  • Patent number: 7754007
    Abstract: An example embodiment of a mixture to be employed in conjunction with water for preparing a slurry that hydrates to form a high strength flooring compound comprises about 50% to about 98% by weight calcium sulfate hemihydrate, about 0.002% to about 1% by weight polysaccharide, and about 0.02% to about 2.5% by weight of a lignosulfanate.
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: July 13, 2010
    Assignee: United States Gypsum Company
    Inventors: Dennis Lettkeman, John W. Wilson, Raymond A. Kaligian, II, Brian K. Ball
  • Publication number: 20090101045
    Abstract: An example embodiment of a mixture to be employed in conjunction with water for preparing a slurry that hydrates to form a high strength flooring compound comprises about 50% to about 98% by weight calcium sulfate hemihydrate, about 0.002% to about 1% by weight polysaccharide, and about 0.02% to about 2.5% by weight of a lignosulfanate.
    Type: Application
    Filed: October 17, 2008
    Publication date: April 23, 2009
    Inventors: Dennis Lettkeman, John W. Wilson, Raymond A. Kaligian, II, Brian K. Ball
  • Patent number: 7516909
    Abstract: An apparatus for mixing an additive into a fluid to form a settable mixture includes a main fluid passageway having an inlet for receiving a supply of the fluid and an outlet for dispensing the fluid, the passageway having a longitudinal axis. The apparatus includes a control valve defining a portion of the main fluid passageway and configured for selectively controlling the flow of fluid in the passageway, an additive injector disposed in the passageway and having an emitter disposed in close relationship with the axis and oriented toward the outlet. A static mixer is disposed between the injector and the outlet for enhancing the uniform mixing of the additive and the fluid. Connection points between the inlet, the valve and the static mixer are configured for smooth transition of fluid and the prevention of at least one of the collection and premature setting of the mixture.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: April 14, 2009
    Assignee: United States Gypsum Company
    Inventors: Raymond A. Kaligian, II, James E. Messer, Dennis Lettkeman, Salvatore C. Immordino, Timothy Ross
  • Publication number: 20060278134
    Abstract: An improved gypsum slurry that includes water, calcium sulfate hemihydrate, a polycarboxylate dispersant and a modifier. The modifier is chemically configured to improve the efficacy of the polycarboxylate dispersant. Preferred modifiers include cement, lime, slaked lime, soda ash, carbonates, silicates and phosphates.
    Type: Application
    Filed: June 9, 2006
    Publication date: December 14, 2006
    Inventors: Dennis Lettkeman, Michael Shake, Qingxia Liu, John Wilson, Brian Randall, David Blackburn
  • Publication number: 20060281837
    Abstract: A slurry is made including water, at least 50% by weight calcium sulfate hemihydrate, and a specific polycarboxylate dispersant prepared using at least three repeating units. A first repeating unit is a vinyl ether-type repeating unit. A second repeating unit includes a maleic acid-type repeating unit. A third repeating unit includes an acrylic acid-type repeating unit. The polymer dispersant has a molecular weight of from about 20,000 to about 80,000 Daltons. The slurry made from this composition can be made at reduced water levels to speed drying and reduce drying costs.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 14, 2006
    Inventors: Dennis Lettkeman, Qingxia Liu, John Wilson, Brian Randall, David Blackburn, Michael Shake
  • Publication number: 20060280899
    Abstract: In a method of making a gypsum slurry, a polycarboxylate dispersant, a modifier and a hydraulic material comprising stucco are selected for use in the slurry. These components are then combined with water to form a slurry, where the modifier is added to the slurry prior to formation of a slurry phase by the water, the stucco and the dispersant. The modifier has been shown to be less effective when added after the dispersant and stucco have been contacted in an aqueous slurry. In a preferred embodiment, an amount of stucco is obtained and the modifier and dispersant are selected. A predissolved solution of a dispersant and modifier is prepared in water to form a solution prior to the addition of the stucco. After mixing the solution, the stucco is added to form the slurry. Optionally, the slurry is then shaped into a product and allowed to set.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 14, 2006
    Inventors: Qingxia Liu, David Blackburn, Michael Shake, Brian Randall, John Wilson, Dennis Lettkeman
  • Publication number: 20060280898
    Abstract: An improved gypsum slurry that includes water, calcium sulfate hemihydrate, a polycarboxylate dispersant and a modifier. The modifier is chemically configured to improve the efficacy of the polycarboxylate dispersant. Preferred modifiers include cement, lime, slaked lime, soda ash, carbonates, silicates and phosphates.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 14, 2006
    Inventors: Dennis Lettkeman, Michael Shake, Qingxia Liu, John Wilson, Brian Randall, David Blackburn
  • Publication number: 20060278130
    Abstract: A gypsum slurry includes water, a hydraulic component including stucco and a polycarboxylate dispersant. The dispersant has two repeating units wherein the first repeating unit is an olefinic unsaturated mono-carboxylic acid repeating unit or an ester or salt, and the second repeating unit is a vinyl or allyl group bound to a polyether by an ether linkage. The slurry can be made into a gypsum panel.
    Type: Application
    Filed: June 9, 2006
    Publication date: December 14, 2006
    Inventors: Qingxia Liu, Michael Shake, David Blackburn, John Wilson, Brian Randall, Dennis Lettkeman
  • Publication number: 20060278135
    Abstract: In a method of making a gypsum slurry, a polycarboxylate dispersant, a modifier and a hydraulic material comprising stucco are selected for use in the slurry. These components are then combined with water to form a slurry, where the modifier is added to the slurry prior to formation of a slurry phase by the water, the stucco and the dispersant. The modifier has been shown to be less effective when added after the dispersant and stucco have been contacted in an aqueous slurry. In a preferred embodiment, an amount of stucco is obtained and the modifier and dispersant are selected. A predissolved solution of a dispersant and modifier is prepared in water to form a solution prior to the addition of the stucco. After mixing the solution, the stucco is added to form the slurry. Optionally, the slurry is then shaped into a product and allowed to set.
    Type: Application
    Filed: June 9, 2006
    Publication date: December 14, 2006
    Inventors: Qingxia Liu, David Blackburn, Michael Shake, Brian Randall, John Wilson, Dennis Lettkeman
  • Publication number: 20060280970
    Abstract: A composition is disclosed for a mixture to be used in conjunction with water for preparing a slurry that hydrates to form a high strength flooring compound. The mixture includes from about 50% to about 98% by weight calcium sulfate hemihydrate. A three repeating unit polycarboxylate dispersant is included in the mixture in amounts from about 0.2% to about 10% by weight. The repeating units include a polyether repeating unit, an acrylic acid-type repeating unit and a maleic acid-type repeating unit. A modifier that enhances the efficacy of the dispersant is also a component of the mixture. When combined with recommended amounts of water, a slurry is formed that is useful as a flooring composition.
    Type: Application
    Filed: June 14, 2005
    Publication date: December 14, 2006
    Inventors: Dennis Lettkeman, John Wilson, William Bedwell
  • Publication number: 20050250888
    Abstract: A composition is disclosed for a mixture to be used in conjunction with water for preparing a slurry that hydrates to form a high strength flooring compound. The mixture includes from about 50% to about 98% by weight calcium sulfate hemihydrate, having at least 25% of the calcium sulfate hemihydrate in the beta-calcined form. A polycarboxylate dispersant is included in the mixture in amounts from about 0.2% to about 10% by weight. The mixture also includes 0.05-50% by weight enhancing component. When combined with recommended amounts of water, a slurry is formed that is useful as a flooring composition.
    Type: Application
    Filed: March 27, 2003
    Publication date: November 10, 2005
    Inventors: Dennis Lettkeman, Raymond Kaligian II, Eldon Whiteside, William Bedwell, Sharon Meiseman
  • Publication number: 20050235882
    Abstract: In conjunction with water, a mixture can be used to prepare a sprayable slurry that hydrates to form a machinable plaster composition. The mixture includes from about 80% to about 98% by weight calcium sulfate hemihydrate, from about 1% to about 5% by weight adhesive binder for adhering said plaster mixture to a substrate and from about 0.001% to about 10% of a polysaccharide. The mixture is made into a slurry by the addition of from 10% to about 50 weight water based on the weight of the mixture.
    Type: Application
    Filed: March 27, 2003
    Publication date: October 27, 2005
    Inventors: Dennis Lettkeman, Raymond Kaligian, Eldon Whiteside
  • Publication number: 20050239924
    Abstract: A mixture is used in conjunction with water is used for preparing a slurry that hydrates to form an exterior gypsum cement. The mixture includes 30-70% by weight hydraulic cement, 30-70% by weight calcined gypsum and 0.05-2.5% polycarboxylate. When the mixture is added to water less than 40 weight % based on the weight of the mixture, a slurry is formed that expands very little while it cures.
    Type: Application
    Filed: March 27, 2003
    Publication date: October 27, 2005
    Inventors: Dennis Lettkeman, Raymond Kaligian II, William Bedwell, Eldon Whiteside
  • Publication number: 20050127208
    Abstract: An apparatus for mixing an additive into a fluid to form a settable mixture includes a main fluid passageway having an inlet for receiving a supply of the fluid and an outlet for dispensing the fluid, the passageway having a longitudinal axis. The apparatus includes a control valve defining a portion of the main fluid passageway and configured for selectively controlling the flow of fluid in the passageway, an additive injector disposed in the passageway and having an emitter disposed in close relationship with the axis and oriented toward the outlet. A static mixer is disposed between the injector and the outlet for enhancing the uniform mixing of the additive and the fluid. Connection points between the inlet, the valve and the static mixer are configured for smooth transition of fluid and the prevention of at least one of the collection and premature setting of the mixture.
    Type: Application
    Filed: February 3, 2005
    Publication date: June 16, 2005
    Inventors: Raymond Kaligian, James Messer, Dennis Lettkeman, Salvatore Immordino, Timothy Ross
  • Publication number: 20020117559
    Abstract: An apparatus for mixing an additive into a fluid to form a settable mixture includes a main fluid passageway having an inlet for receiving a supply of the fluid and an outlet for dispensing the fluid, the passageway having a longitudinal axis. The apparatus includes a control valve defining a portion of the main fluid passageway and configured for selectively controlling the flow of fluid in the passageway, an additive injector disposed in the passageway and having an emitter disposed in close relationship with the axis and oriented toward the outlet. A static mixer is disposed between the injector and the outlet for enhancing the uniform mixing of the additive and the fluid. Connection points between the inlet, the valve and the static mixer are configured for smooth transition of fluid and the prevention of at least one of the collection and premature setting of the mixture.
    Type: Application
    Filed: July 31, 2001
    Publication date: August 29, 2002
    Inventors: Raymond A. Kaligian, James E. Messer, Dennis Lettkeman, Salvatore C. Immordino, Timothy Ross