Patent ID: 8468710

Claim:
A device for depositing a dust mark on a surface, comprising: a linear guide having a first end, a second end, and a stop proximate said second end; a dust receptacle that reciprocally moves along said linear guide between said stop and a point a predetermined distance above said stop, wherein said dust receptacle defines an interior chamber and has a discharge opening that leads into said interior chamber; marking dust disposed in said interior chamber of said dust receptacle; a biasing element that biases said dust receptacle against said stop with a predetermined biasing force; a mechanism for applying force to said dust receptacle in excess of said predetermined biasing force, therein moving said dust receptacle away from said stop along said linear guide into a cocked position, wherein when released from said cocked position, said biasing element rapidly moves said dust receptacle along said linear guide to said stop, causing a volume of said marking dust to exit said discharge opening and travel past said second end of said linear guide to mark a surface.