Granted Patent
Utility
US 5,293,821 · App. 07/541,959
Delay initiator for blasting
Inventors:
Donald C. True, Raymond L. Carriere
Patented Case
View Patent ↗
Granted: Mar 15, 1994
Filed: Jun 22, 1990
Inventors
Donald C. True
Raymond L. Carriere
Assignee (at issue)
ICI Canada, 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.