Granted Patent
Utility
US 4,997,136 · App. 07/466,672
Hammer mill provided with a device for locking the hammers in a retracted position in the drum
Inventor:
Arnaud Becker
Patented Case
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Granted: Mar 5, 1991
Filed: Jan 17, 1990
Inventor
Arnaud Becker
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.