Patents by Inventor R. D. Forsgren

R. D. Forsgren 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).

  • Respirator air filter cartridge with a replaceable filter element
    Patent number: 5222488
    Abstract: A respirator cartridge having a housing, a replaceable filter and a cover is provided. The cartridge is sealed by a lip on the filter frame and sealing rings on the housing and cover. The cover is releasably connected to the housing by protuberances on the cover which slide along ramp-up lock devices on the housing when the cover is turned, compressing the filter frame and sealing the cartridge.
    Type: Grant
    Filed: July 11, 1991
    Date of Patent: June 29, 1993
    Assignee: Donaldson Company, Inc.
    Inventor: R. D. Forsgren