Granted Patent
Utility
US 6,588,455 · App. 10/089,655
Method and apparatus for blocking pipes
Inventor:
Andrew Welfare
Patented Case
View Patent ↗
Granted: Jul 8, 2003
Filed: Jul 8, 2002
Inventor
Andrew Welfare
Assignee (at issue)
GLYNWED PIPE SYSTEMS LIMITED
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.