Granted Patent
Utility
US 5,643,536 · App. 08/334,866
Method and apparatus for metering a reagent into a flowing medium
Inventor:
Helmut Schmelz
Patented Case
View Patent ↗
Granted: Jul 1, 1997
Filed: Nov 4, 1994
Inventor
Helmut Schmelz
Assignee (at issue)
Siemens Aktiengesellschaft
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.