Granted Patent
Utility
US 4,517,239 · App. 06/444,802
Fiber-cement/plywood walking surface
Inventor:
Thomas L. Thompson
Patented Case
View Patent ↗
Granted: May 14, 1985
Filed: Nov 26, 1982
Inventor
Thomas L. Thompson
Assignee (at issue)
THOM-McI
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.