Granted Patent
Utility
US 4,272,039 · App. 05/953,097
Electronic hang glider hook-up warning system
Inventor:
Thomas Hollingsworth
Patented Case
View Patent ↗
Granted: Jun 9, 1981
Filed: Oct 19, 1978
Inventor
Thomas Hollingsworth
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.