Granted Patent
Utility
US 4,897,067 · App. 07/300,918
Diaphragh-type game caller with removable spacer
Inventor:
Frank R. Piper
Patented Case
View Patent ↗
Granted: Jan 30, 1990
Filed: Jan 24, 1989
Inventor
Frank R. Piper
Assignee (at issue)
Penn's Woods Products, 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.