Building blocks type writing instrument

Abstract

A building blocks type writing instrument having a plurality of writing units, each of which is provided with a pencil lead at its front end, and at least one coupling unit engaged insertedly axially with each other in series. The writing units is formed having the front end provided with a tubular projection for insertion of pencil lead and the rear end with an insertion hole for insertion and engagement of the tubular projection at the front end, and on the outer circumferential surface at least one engaging projection at least one coupling groove corresponding to the engaging projection for engagement side by side transversely of another writing unit by corresponding engaging groove and projection. The coupling unit has a tubular body with front end and the lower portion provided on the two back to back lateral sides each cross shape coupling unit for cross engagement of the writing units. As one with a tubular projection corresponding to that of the writing unit. On the rear end there is an insertion hole corresponding to that of the writing unit. Further on the two lateral sides where a tubular projection is absent are located with engaging projection and or coupling grooves corresponding to the those of the writing unit. The tubular body and the three tubular projections, in total, form a T-shaped coupling unit.

Dependencies are inferred from the claim text.