Granted Patent
Utility
US 4,648,521 · App. 06/867,120
Composite metal and plastic tank
Inventors:
Larry D. Thomas, David L. Waltke, Gary Gibson
Patented Case
View Patent ↗
Granted: Mar 10, 1987
Filed: May 27, 1986
Inventors
Larry D. Thomas
David L. Waltke
Gary Gibson
Assignee (at issue)
Hoover Limited
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.