E. Keller Barnhardt has been granted 4 US patents while listed as an inventor at Cem. The first was granted in 2008 and the most recent in February 2012. E. Keller Barnhardt ranks #1,080,739 of 4,157,543 US inventors in our database (top 26.0%). Patent records list E. Keller Barnhardt in Charlotte, NC, US.