Granted Patent
Utility
US 4,850,828 · App. 07/123,552
Plunger pump of quick pressure-rise type
Inventor:
Keitaro Yonezawa
Patented Case
View Patent ↗
Granted: Jul 25, 1989
Filed: Nov 20, 1987
Inventor
Keitaro Yonezawa
Assignee (at issue)
KOSMEK LTD.
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.