Granted Patent
Utility
US 3,958,313 · App. 05/476,476
Method, apparatus and product for improved pipe-to-manhole sealing
Inventor:
John C. Rossborough
Patented Case
View Patent ↗
Granted: May 25, 1976
Filed: Jun 5, 1974
Inventor
John C. Rossborough
Assignee (at issue)
Merchants National Bank of Manchester
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.