Patents by Inventor Jeffrey J. Theisen

Jeffrey J. Theisen 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: 8425769
    Abstract: A filter arrangement includes a filter cartridge having a first filter element and a second filter element. The first filter element includes a first tubular section of filter media extending between first and second end caps and defining a first open filter interior. The second filter element includes a second tubular section of filter media operably oriented in the first open filter interior. The second tubular section of filter media extends between third and fourth end caps and defines a second open filter interior. The first end cap defines an inner container and an outer container circumscribing the inner container. The outer container is secured to the first tubular section of filter media. The inner container has an end wall axially spaced from the outer container. The third end cap has a media end secured to the second tubular section of filter media and a tubular wall axially extending from the media end. The tubular wall is circumscribed by the inner container of the first end cap.
    Type: Grant
    Filed: January 8, 2008
    Date of Patent: April 23, 2013
    Assignee: Donaldson Company, Inc.
    Inventors: Gary H. Gift, Jeffrey J. Theisen
  • Publication number: 20100140155
    Abstract: A filter arrangement includes a filter cartridge having a first filter element and a second filter element. The first filter element includes a first tubular section of filter media extending between first and second end caps and defining a first open filter interior. The second filter element includes a second tubular section of filter media operably oriented in the first open filter interior. The second tubular section of filter media extends between third and fourth end caps and defines a second open filter interior. The first end cap defines an inner container and an outer container circumscribing the inner container. The outer container is secured to the first tubular section of filter media. The inner container has an end wall axially spaced from the outer container. The third end cap has a media end secured to the second tubular section of filter media and a tubular wall axially extending from the media end. The tubular wall is circumscribed by the inner container of the first end cap.
    Type: Application
    Filed: January 8, 2008
    Publication date: June 10, 2010
    Applicant: Donaldson Co., Inc.
    Inventors: Gary H. Gift, Jeffrey J. Theisen
  • Patent number: 5885447
    Abstract: A filter arrangement for filtering fluid comprises a housing having an inlet and an outlet, a first cylindrical construction, a second cylindrical construction, and a bypass arrangement. The first construction includes filter media mounted within the housing. The first construction defines a first open filter interior. The first open filter interior includes a first dimension being a largest dimension across a cross-section of the first open filter interior. The second construction includes a filtration construction mounted within the housing. The second construction defines a second open filter interior. The second open filter interior includes a second dimension being a largest dimension across a cross-section of the second open filter interior. The second dimension is at least as large as the first dimension. The bypass arrangement has an open position and a closed position.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: March 23, 1999
    Assignee: Donaldson Company, Inc.
    Inventors: Jeffrey J. Theisen, Kathryn A. Legault
  • Patent number: 5501791
    Abstract: A filter head adapted for use with spin-on filters is shown. The filter head carries a spring load piston which is normally biased to close a filter bypass channel. A fluid pressure increase caused by a clogged filter causes the piston to move opening the bypass and at the same time opening a signal channel between a source of fluid pressure and a signal outlet.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: March 26, 1996
    Assignee: Donaldson Company, Inc.
    Inventors: Jeffrey J. Theisen, John F. Connelly