Granted Patent
Utility
US 4,528,913 · App. 06/433,331
Gravity outlet sliding gate seal
Inventor:
Robert W. Randolph
Patented Case
View Patent ↗
Granted: Jul 16, 1985
Filed: Oct 7, 1982
Inventor
Robert W. Randolph
Assignee (at issue)
ACF Industries Incorporated
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.