Granted Patent
Utility
US 5,649,713 · App. 08/528,526
Gasket for hub and spigot pipe joints
Inventor:
Harry J. Ledgerwood
Patented Case
View Patent ↗
Granted: Jul 22, 1997
Filed: Sep 14, 1995
Inventor
Harry J. Ledgerwood
Assignee (at issue)
Tyler Pipe Company, a div. of Ransom Industries, 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.