Granted Patent
Utility
US 4,548,009 · App. 06/589,366
Concrete expansion joint
Inventor:
Donald E. Dahowski
Patented Case
View Patent ↗
Granted: Oct 22, 1985
Filed: Mar 14, 1984
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.