Granted Patent
Utility
US 5,433,270 · App. 08/235,363
Cementing plug
Inventor:
Karl K. LaFleur
Patented Case
View Patent ↗
Granted: Jul 18, 1995
Filed: Apr 29, 1994
Inventor
Karl K. LaFleur
Assignee (at issue)
LaFleur Petroleum Services, 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.