Granted Patent
Utility
US 4,640,521 · App. 06/703,088
Dolly with tank latch
Inventor:
Robert C. Berfield
Patented Case
View Patent ↗
Granted: Feb 3, 1987
Filed: Feb 19, 1985
Inventor
Robert C. Berfield
Assignee (at issue)
SHOP VAC 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.