Patents Assigned to E. Neal Caldwell
  • Water filter system
    Patent number: 8778175
    Abstract: A slow/intermittent sand filter that purifies polluted water by flowing through sand in a manner that achieves greater purity and permits simpler and more effective maintenance than existing filters.
    Type: Grant
    Filed: June 14, 2011
    Date of Patent: July 15, 2014
    Assignee: E. Neal Caldwell
    Inventors: E. Neal Caldwell, John Kevin Hodges