Granted Patent
Utility
US 5,877,456 · App. 08/898,211
System for checking the calibration of gravimetic feeders and belt scales
Inventors:
John C. Homer, J. Ronald Walsh, David P. Ratcliffe
Patented Case
View Patent ↗
Granted: Mar 2, 1999
Filed: Jul 22, 1997
Inventors
John C. Homer
J. Ronald Walsh
David P. Ratcliffe
Assignee (at issue)
Federal Signal Corporation
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.