Granted Patent
Utility
US 4,323,096 · App. 06/150,469
Combination vacuum relief valve and pressure relief valve which are protected from the atmosphere
Inventors:
Richard H. Dugge, Dallas W. Rollins
Patented Case
View Patent ↗
Granted: Apr 6, 1982
Filed: May 16, 1980
Inventors
Richard H. Dugge
Dallas W. Rollins
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.