Granted Patent
Utility
US 4,530,605 · App. 06/563,696
Check valve arrangement for the discharge end of an extruder, plastifier or the like
Inventors:
Martin Eichlseder, Erwin Burkle
Patented Case
View Patent ↗
Granted: Jul 23, 1985
Filed: Dec 20, 1983
Inventors
Martin Eichlseder
Erwin Burkle
Assignee (at issue)
KraussMaffei GmbH
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.