Granted Patent
Utility
US 6,638,539 · App. 09/935,550
Trace elements
Inventors:
Robert Naylor Laurie, Lambertus Petrus Vosloos
Patented Case
View Patent ↗
Granted: Oct 28, 2003
Filed: Aug 24, 2001
Inventors
Robert Naylor Laurie
Lambertus Petrus Vosloos
Assignee (at issue)
Warburton Technology 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.