Granted Patent
Utility
US 5,020,558 · App. 07/605,666
Automatic umbrella having stable extending and folding structure
Inventor:
Sheng-Fu Huang
Patented Case
View Patent ↗
Granted: Jun 4, 1991
Filed: Oct 29, 1990
Inventor
Sheng-Fu Huang
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.