Granted Patent
Utility
US 4,512,309 · App. 06/490,974
Spark control apparatus
Inventor:
Chusak Tansuwan
Patented Case
View Patent ↗
Granted: Apr 23, 1985
Filed: May 2, 1983
Inventor
Chusak Tansuwan
Assignee (at issue)
ACF Industries Incorporated
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.