Granted Patent
Utility
US 4,881,344 · App. 07/316,087
Sleeve for plant germination substrate
Inventors:
Gunter Frey, Rudolf Wagner
Patented Case
View Patent ↗
Granted: Nov 21, 1989
Filed: Feb 27, 1989
Inventors
Gunter Frey
Rudolf Wagner
Assignee (at issue)
Firma Carl Freudenberg
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.