Patents by Inventor Douglas Ewald

Douglas Ewald 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: 4151092
    Abstract: A portable water filter has a first cylindrical container for holding a quantity of liquid to be treated. Included in the filter is a water filter cartridge which is mounted with respect to the first container for treating liquid which is pumped through the filtering material within the cartridge. A second container is coupled to the cartridge and arranged to receive the liquid pumped through the cartridge from the first container. The arrangement is such as to permit manual pumping of the liquid from that first container through the cartridge into the second container. Desirably, the pumping action is achieved by telescopingly inserting the second container within the first container. In addition to its direct treatment of the liquid, the filtering material serves to remove undesired color, taste and odor induced by a disinfectant or bactericidal agent used with the system.
    Type: Grant
    Filed: July 11, 1977
    Date of Patent: April 24, 1979
    Assignee: Teledyne Industries, Inc.
    Inventors: Thomas Grimm, Douglas Ewald
  • Patent number: D416883
    Type: Grant
    Filed: May 6, 1998
    Date of Patent: November 23, 1999
    Assignee: Allflex USA, Inc.
    Inventors: Gregg Wagner, Robert Stewart, Douglas Ewald