Patents by Inventor Cornelis Grefhorst

Cornelis Grefhorst 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: 8029711
    Abstract: A method for producing a core sand and/or mold sand for foundry purposes mixes a granular mineral mold base material with an additive and an inorganic binder. An inorganic swelling additive having a swelling index of at least 9, in other words a higher swelling index that that achieved for coal, is used as an additive. Alternatively, it is also possible to work with an inorganic additive, for example with macro-crystalline graphite, whereby the finished mixture of the mold base material, the additive, and the binder is compacted to a density increase of at least 20 g/dm3.
    Type: Grant
    Filed: June 10, 2008
    Date of Patent: October 4, 2011
    Assignee: S & B Industrial Minerals GmbH
    Inventors: Cornelis Grefhorst, Spyridon Tzintzos
  • Publication number: 20090025606
    Abstract: A method for producing a core sand and/or mold sand for foundry purposes mixes a granular mineral mold base material with an additive and an inorganic binder. An inorganic swelling additive having a swelling index of at least 9, in other words a higher swelling index that that achieved for coal, is used as an additive. Alternatively, it is also possible to work with an inorganic additive, for example with macro-crystalline graphite, whereby the finished mixture of the mold base material, the additive, and the binder is compacted to a density increase of at least 20 g/dm3.
    Type: Application
    Filed: June 10, 2008
    Publication date: January 29, 2009
    Inventors: Cornelis Grefhorst, Spyridon Tzintzos
  • Patent number: 7281570
    Abstract: A method for producing a core sand and/or molding sand for casting purposes mixes a basic granular mineral molding material such as silica sand with an additive based on an organic or inorganic component, a binding agent being optionally added. The additive is coarsely ground prior to the mixing process, more than 50 percent by weight of the grains having a minimum size of approximately 0.05 mm.
    Type: Grant
    Filed: June 11, 2004
    Date of Patent: October 16, 2007
    Assignee: S & B Industrial Minerals GmbH
    Inventors: Karl Koch, Cornelis Grefhorst
  • Patent number: 7188660
    Abstract: A method is for producing a moulding sand that is in particular recirculated, for foundry purposes. A mixture of a granular substance and aggregates, such as a binding agent and water, are added to a material that is not capable of swelling in water. The latter material has cavities with a specific surface area of more than 10 m2/g, in particular more than 50 m2/g and preferably more than 100 m2/g, for improving the characteristics of the moulding sand and/or for reducing the emission of harmful and/or odorous substances.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: March 13, 2007
    Assignee: IKO Minerals GmbH
    Inventors: Cornelis Grefhorst, Karl Koch
  • Publication number: 20060151145
    Abstract: The invention relates to a method for producing a core sand and/or molding sand for casting purposes. According to said method, a basic granular mineral molding material such as silica sand is mixed with an additive based on an organic or inorganic component, a binding agent being optionally added. According to the invention, the additive is coarsely ground prior to the mixing process, more than 50 percent by weight of the grains having a minimum size of approximately 0.05 mm.
    Type: Application
    Filed: June 11, 2004
    Publication date: July 13, 2006
    Inventors: Karl Koch, Cornelis Grefhorst
  • Publication number: 20050121168
    Abstract: A method for producing a moulding sand that is in particular recirculated, for foundry purposes. According to the invention, a mixture of a granular substance and aggregates, such as a binding agent and water, are added to a material that is not capable of swelling in water. The latter material comprises cavities with a specific surface area of more than 10 m2/g, in particular more than 50 m2/g and preferably more than 100 m2/g, for improving the characteristics of the moulding sand and/or for reducing the emission of harmful and/or odorous substances.
    Type: Application
    Filed: February 7, 2003
    Publication date: June 9, 2005
    Inventors: Cornelis Grefhorst, Karl Koch