Granted Patent
Utility
US 4,881,880 · App. 07/183,196
Drain for internal gear hydraulic device
Inventor:
Andrew N. Dlugokecki
Patented Case
View Patent ↗
Granted: Nov 21, 1989
Filed: Apr 19, 1988
Inventor
Andrew N. Dlugokecki
Assignee (at issue)
Parker-Hannifin Corporation
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.