Granted Patent
Utility
US 4,490,067 · App. 06/331,842
Modular drain system
Inventor:
Donald E. Dahowski
Patented Case
View Patent ↗
Granted: Dec 25, 1984
Filed: Dec 17, 1981
Inventor
Donald E. Dahowski
Assignee (at issue)
Quaker Plastic Corporation
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.