Granted Patent
Utility
US 4,758,556 · App. 06/891,850
Cephem derivatives
Inventors:
Walter Durckheimer, Dieter Bormann, Eberhard Ehlers, Elmar Schrinner, Rene Heymes
Patented Case
View Patent ↗
Granted: Jul 19, 1988
Filed: Mar 30, 1978
Inventors
Walter Durckheimer
Dieter Bormann
Eberhard Ehlers
Elmar Schrinner
Rene Heymes
Assignee (at issue)
Hoechst 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.