Granted Patent
Utility
US 4,989,581 · App. 07/531,557
Torsional strain relief for borescope
Inventors:
Richard A. Tamburrino, Alan S. Knieriem
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: Jun 1, 1990
Inventors
Richard A. Tamburrino
Alan S. Knieriem
Assignee (at issue)
Welch Allyn, Inc.
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.