Granted Patent
Utility
US 4,986,609 · App. 06/776,447
Load sensing proportioning valve for brake system
Inventors:
Joe S. Cole, Neil B. Christopher
Patented Case
View Patent ↗
Granted: Jan 22, 1991
Filed: Sep 16, 1985
Inventors
Joe S. Cole
Neil B. Christopher
Assignee (at issue)
Surfaces, 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.