Patents by Inventor Kathleen A. Abrahamson

Kathleen A. Abrahamson 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).

  • Method of servicing an air cleaner and of filtering engine intake air using prefilter arrangements
    Patent number: 6015452
    Abstract: A filter arrangement is provided. The filter arrangement generally includes an air filter having an upstream surface with a prefilter positioned thereon. The prefilter preferably include at least two layers of depth media. In preferred systems, the prefilter includes two layers of depth media secured to one another by stitching. In certain preferred arrangements disclosed, the prefilter include an upstream layer of fibrous depth media and a downstream layer of foam depth media, with the two layers stitched to one another along peripheral edges. The invention also concerns provision of prefilters, and also air filter arrangements which include housings having air filters with prefilters according to the present invention operably positioned therein. Methods of construction and use are also provided.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: January 18, 2000
    Assignee: Donaldson Company, Inc.
    Inventors: Larry R. Nepsund, Kathleen A. Abrahamson, Thomas A. Boeckermann, James K. Elfstrand
  • Filter arrangement including removable filter with first and second media secured together
    Patent number: 5858044
    Abstract: A filter arrangement is provided. The filter arrangement generally includes an air filter having an upstream surface with a prefilter positioned thereon. The prefilter preferably includes at least two layers of depth media. In preferred systems, the prefilter includes two layers of depth media secured to one another by stitching. In certain preferred arrangements disclosed, the prefilter includes an upstream layer of fibrous depth media and a downstream layer of foam depth media, with the two layers stitched to one another along peripheral edges. The invention also concerns provision of prefilters, and also air filter arrangements which include housings having air filters with prefilters according to the present invention operably positioned therein. Methods of construction and use are also provided.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: January 12, 1999
    Assignee: Donaldson Company, Inc.
    Inventors: Larry R. Nepsund, Kathleen A. Abrahamson, Thomas A. Boeckermann, James K. Elfstrand
  • Restriction indicator
    Patent number: D378744
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: April 8, 1997
    Assignee: Donaldson Company, Inc.
    Inventors: Kathleen A. Abrahamson, Thomas A. Boeckemann, James Efstrand
  • Panel filter construction
    Patent number: D402361
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: December 8, 1998
    Assignee: Donaldson Company, Inc.
    Inventors: Larry R. Nepsund, Kathleen A. Abrahamson, Thomas A. Boeckermann, James K. Elfstrand
  • Filter sleeve
    Patent number: D404807
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: January 26, 1999
    Assignee: Donaldson Company, Inc.
    Inventors: Larry R. Nepsund, Kathleen A. Abrahamson, Thomas A. Boeckermann, James K. Elfstrand
  • Filter element having circular sleeve
    Patent number: D407808
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: April 6, 1999
    Assignee: Donaldson Company, Inc.
    Inventors: Larry R. Nepsund, Kathleen A. Abrahamson, Thomas A. Boeckermann, James K. Elfstrand