Granted Patent
Utility
US 4,884,384 · App. 07/035,217
Arrangement for laying concrete floors
Inventors:
Stig-åke Ljungkvist, Lennart Johansson
Patented Case
View Patent ↗
Granted: Dec 5, 1989
Filed: Apr 6, 1987
Inventors
Stig-åke Ljungkvist
Lennart Johansson
Assignee (at issue)
Permaban Southeast, 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.