Granted Patent
Utility
US 5,989,421 · App. 08/943,615
Bag filter rim system
Inventors:
Scott J. Davis, John D. Vander Ark, Jr.
Patented Case
View Patent ↗
Granted: Nov 23, 1999
Filed: Oct 3, 1997
Inventors
Scott J. Davis
John D. Vander Ark, Jr.
Assignee (at issue)
Delaware Capital Formation, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.