An apparatus and method for clearing a playing surface are provided. The apparatus preferably includes a chassis or frame, a sensor connected to the chassis to sense a location of a line on a playing surface that needs to be cleaned, and a drive connected to the chassis to drive the chassis in a selected...http://www.google.fr/patents/US7245994?utm_source=gb-gplus-shareBrevet US7245994 - Apparatus for cleaning lines on a playing surface and associated methods, enhancements
Apparatus for cleaning lines on a playing surface and associated methods ...
