Granted Patent
Utility
US 5,122,286 · App. 07/626,476
Filter changing apparatus for flowable plastic material
Inventors:
Udo Kreyenborg, Manfred Hangmann, Ludger Wilken-Trenkamp
Patented Case
View Patent ↗
Granted: Jun 16, 1992
Filed: Dec 12, 1990
Inventors
Udo Kreyenborg
Manfred Hangmann
Ludger Wilken-Trenkamp
Assignee (at issue)
KREYENBORG VERWALTUNGEN UND BETEILIGUNGEN GMBH & CO. KG
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.