Patent attributes
A spool for a chalk box may include a core member extending substantially parallel to an axis of rotation of the spool, a first sidewall disposed in a plane substantially perpendicular to the axis of rotation of the spool at a first end of the core member, and a second sidewall disposed in a plane substantially parallel to the first sidewall at a second end of the core member. The string may be configured to be retained on the spool by being wound onto the core member. The first sidewall may include a first anchorage orifice and a second anchorage orifice spaced apart from each other and each passing through the first sidewall from an inside surface of the first sidewall to an outside surface of the first sidewall. A spool groove may be formed on the outside surface of the first sidewall extending from the first anchorage orifice to the second anchorage orifice.