Granted Patent
Utility
US 4,639,039 · App. 06/774,447
Height adjustment mechanism for chair backrest
Inventor:
Kyle P. Donovan
Patented Case
View Patent ↗
Granted: Jan 27, 1987
Filed: Sep 10, 1985
Inventor
Kyle P. Donovan
Assignee (at issue)
Milsco Manufacturing Company
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.