Granted Patent
Utility
US 4,374,500 · App. 06/265,515
Seed planter depth control
Inventor:
Lawerence D. Westerfield
Patented Case
View Patent ↗
Granted: Feb 22, 1983
Filed: May 20, 1981
Inventor
Lawerence D. Westerfield
Assignee (at issue)
International Harvester Company
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.