Abstract: An automatic writing apparatus includes a plurality of writing elements axially positioned one by one, each of which has a tip portion at the front end and an element cap having a hole for receiving therein the tip portion of an adjacent one of the writing elements; an outer tube for receiving therein a first and a second ones of the writing elements, wherein the outer tube includes a pen-tip outlet for holding the first one of the writing elements; and an inner tube for receiving therein the others of the writing elements and propelling the second one of the writing elements toward the pen-tip outlet for replacing the first one of the writing elements.

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.