Granted Patent
Utility
US 5,146,949 · App. 07/653,883
Check valve with spring loaded clapper assembly
Inventors:
James G. Retzloff, Perin E. Truax
Patented Case
View Patent ↗
Granted: Sep 15, 1992
Filed: Jan 4, 1991
Inventors
James G. Retzloff
Perin E. Truax
Assignee (at issue)
Viking Group, 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.