Granted Patent
Utility
US 6,581,641 · App. 09/828,347
One-way valve for use with vacuum pump
Inventors:
Janet L. Skeens, Gerald Sweeney
Patented Case
View Patent ↗
Granted: Jun 24, 2003
Filed: Apr 5, 2001
Inventors
Janet L. Skeens
Gerald Sweeney
Assignee (at issue)
ILLINOIS TOOL WORKS INC.
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.