Patents by Inventor Donald M. Kolehmainen

Donald M. Kolehmainen 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).

  • Two stage vacuum cleaner filter
    Patent number: 5733351
    Abstract: A two stage vacuum cleaner filter is disclosed. The filter includes a first stage outer filter extending in a closed circumferential path with a second stage inner filter located in immediate proximity to and within the first stage outer filter. Sealing elements for securing opposite ends of the first stage outer filter and second stage inner filter to each other are provided. The second stage inner filter stops particles that might leak through the first stage outer filter.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: March 31, 1998
    Assignee: Emerson Electric Co.
    Inventors: David R. Hult, Donald M. Kolehmainen, Jeffrey L. Young