Granted Patent
Utility
US 4,836,241 · App. 07/086,600
Valve for the controlling of a pressure differential
Inventor:
Siegfried Schoenwald
Patented Case
View Patent ↗
Granted: Jun 6, 1989
Filed: Aug 18, 1987
Inventor
Siegfried Schoenwald
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.