Abstract: Capillary writing pen of the type embodying a cylindrical body having an open end and a pen tip with reservoir insertable as a cartridge within the cylindrical body. Particularly the improvement consisting of providing wave like complemental surfaces at the abutting interface of the cylinder open end and cartridge tip, such that transverse twisting of the cartridge with respect to the cylinder results in axial separation of the cartridge with respect to the cylinder. The improvement eliminates the necessity for the expensive and time consuming complemental threading of the cylinder interior and cartridge exterior and is readily producible in conventional plastic dies.

Abstract: Automatic drafting device of the type employing a tubular writing pen, particularly an adjustable sealing element which is used against the writing tip of the pen when the pen is in a retracted rest mode. The sealing element is laterally disengaged from the pen tip when the pen is an extended writing mode. The sealing element which may be in the form of an elastic spheroid prevents drying out of ink within the capillary channel when the pen is not in use. The blocking assembly is characterized by its ability both to lock the tubular writing pen in its rest position and to lock the sealing element in its laterally outward position so as to avoid interference with the pen during temporary moments of non-writing.

Abstract: A process for the production of lettering or symbol templates by production of symbol cut-outs in a template sheet consisting of thermoplastic plastic, characterized by forcing the cut-out portions of the symbols in a shaping or forging step, and subsequently cutting off the protruding forced-out portions.

Abstract: A receptacle or protective cap for the writing point of a tube writing pen, the pen comprising a writing cone provided with a writing tube and fitted into a sleeve, there being an ink equalization chamber in a space between the cone and the sleeve, wherein the cap comprises an open-ended hollow body adapted to be secured over the sleeve by its open end, the other end being closed, and wherein the cap has an improved inner annular sealing face for engaging against the end of the sleeve when the cap is secured over the sleeve, the sealing face being formed by a layer of soft resilient material attached to an annular rigid base.

Abstract: The invention relates to a method for drawing, particularly automatic drawing with at least one tubular pen which has a cylindrical body with the writing tubule held in front in the latter, as well as to a drawing instrument, particularly for automatic drawing apparatus.