US Patent 7197832 String line box tool

A string line box tool comprising a chalk line box and a line block integral therewith used for guiding a string line rearward from the chalk line box through a groove in the line block in order to provide a free holding string line for carpentry or construction work. To effect this condition the hook shaped protrusion of the line block will hook onto one end of a work project while the L-shaped metal tab on the free end of the string line will hook onto the opposite end of the work project, the string line being under tension during this condition.