Granted Patent
Utility
US 6,640,495 · App. 09/235,107
Safety hatch for preventing fall-through and unauthorized entry
Inventor:
Timothy J. McKernan
Patented Case
View Patent ↗
Granted: Nov 4, 2003
Filed: Jan 21, 1999
Inventor
Timothy J. McKernan
Assignee (at issue)
Syracuse Castings Sales 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.