Granted Patent
Utility
US 4,666,136 · App. 06/760,253
Spring unit
Inventor:
Robert C. Hagemeister
Patented Case
View Patent ↗
Granted: May 19, 1987
Filed: Jul 29, 1985
Inventor
Robert C. Hagemeister
Assignee (at issue)
Webster Spring Co. 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.