Granted Patent
Utility
US 4,512,501 · App. 06/410,459
Down-locking dispensing pump with guided check valve hold-down structure
Inventor:
Donald D. Foster
Patented Case
View Patent ↗
Granted: Apr 23, 1985
Filed: Aug 23, 1982
Inventor
Donald D. Foster
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.