Granted Patent
Utility
US 4,257,543 · App. 06/066,463
Three-plate slide valve closure for liquid melt containers
Inventors:
Udo Muschner, Emil Schnurrenberger
Patented Case
View Patent ↗
Granted: Mar 24, 1981
Filed: Aug 13, 1979
Inventors
Udo Muschner
Emil Schnurrenberger
Assignee (at issue)
Stopinc 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.