Granted Patent
Utility
US 5,893,810 · App. 08/695,004
Tennis rackets
Inventor:
Helmut Umlauft
Patented Case
View Patent ↗
Granted: Apr 13, 1999
Filed: Aug 9, 1996
Inventor
Helmut Umlauft
Assignee (at issue)
Head Sport AG
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.