Granted Patent
Utility
US 4,640,528 · App. 06/760,595
Torsion-absorbing highway semitrailer
Inventors:
William C. Boyles, Douglas R. Hagge, Clifford V. Johnston
Patented Case
View Patent ↗
Granted: Feb 3, 1987
Filed: Jul 30, 1985
Inventors
William C. Boyles
Douglas R. Hagge
Clifford V. Johnston
Assignee (at issue)
Cardinal Industries, 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.