Granted Patent
Utility
US 4,878,697 · App. 07/108,144
Compression coupling for plastic pipe
Inventor:
Ralph E. Henry
Patented Case
View Patent ↗
Granted: Nov 7, 1989
Filed: Oct 14, 1987
Inventor
Ralph E. Henry
Assignee (at issue)
Dresser Industries, 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.