Granted Patent
Utility
US 4,316,574 · App. 06/137,247
Sleeve valve for flexible bags
Inventor:
J. George Lepisto
Patented Case
View Patent ↗
Granted: Feb 23, 1982
Filed: Apr 4, 1980
Inventor
J. George Lepisto
Assignee (at issue)
Champion International Corporation Limited
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.