Granted Patent
Utility
US 4,854,768 · App. 07/058,037
Depressible roadway marker
Inventors:
Robert M. Flanagan, Sidney A. Heenan
Patented Case
View Patent ↗
Granted: Aug 8, 1989
Filed: Jun 4, 1987
Inventors
Robert M. Flanagan
Sidney A. Heenan
Assignee (at issue)
ARTERICA 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.