Granted Patent
Utility
US 6,223,871 · App. 09/341,044
Cable drum with integrated frequency converter
Inventor:
Michael Steffen
Patented Case
View Patent ↗
Granted: May 1, 2001
Filed: Jun 30, 1999
Inventor
Michael Steffen
Assignee (at issue)
Wacker-Werke 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.