Granted Patent
Utility
US 4,813,846 · App. 07/043,688
Inserting device for vacuum apparatus
Inventor:
Dirk Helms
Patented Case
View Patent ↗
Granted: Mar 21, 1989
Filed: Apr 29, 1987
Inventor
Dirk Helms
Assignee (at issue)
Leybold-Heraeus GmbH
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.