Granted Patent
Utility
US 4,994,454 · App. 07/457,253
Cepham derivatives
Inventors:
Jan Verweij, Jan J. DeKoning, Hendrik A. Witkamp
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Dec 27, 1989
Inventors
Jan Verweij
Jan J. DeKoning
Hendrik A. Witkamp
Assignee (at issue)
Gist-Brocades N.V.
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.