Granted Patent
Utility
US 4,367,052 · App. 06/154,681
Flat rate spring particularly adapted for typewriter cartridges
Inventor:
Donald J. Steger
Patented Case
View Patent ↗
Granted: Jan 4, 1983
Filed: May 30, 1980
Inventor
Donald J. Steger
Assignee (at issue)
International Business Machines Corporation
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.