Abstract: A writing pen of the type employing low viscosity liquid ink retained in a reservoir in the pen body by means of a capillary collector element. The nib of the patent is color coded to correspond with the color of ink contained within the pen. A closure cap for the pen is formed with large openings in the region surrounding the color coded nib, to provide visual access to the colored nib when the cap is mounted on the pen body. An air passage, necessary for the reservoir of the pen to “breath”, is extended to have its outlet immediately adjacent the writing tip of the pen, and the closure cap is provided with an internal sealing cup at its closed end, which is received over the writing tip and closely adjacent portions of the nib, to seal both the writing tip and the air passage, when the closure cap is in place.

Abstract: A multi-color pen system is provided in which there are a plurality of liquid ink pen units, each of a different color. Each unit includes a nib and writing point, a collector element providing capillary passages for air and ink, and a tubular receiving body which houses the collector and forms an ink reservoir above the collector. Each unit is a complete, functioning pen device. The receiving body of each unit is threaded to receive a detachable pen holder to facilitate gripping the pen during use.

Abstract: An inexpensive writing pen for low viscosity liquid inks and formed with an internal ink reservoir and a capillary system for admitting air into the reservoir. The ink reservoir is formed directly by the walls of the pen body, which form an internal cavity. Transfer of heat from the writer's hand into the region of the ink reservoir is inhibited by providing projection elements and intervening air spaces, which form the effective outer surface of the pen body. Preferably, the material of the pen body extends substantially above the upper limits of the internal ink reservoir, and is provided in those upper areas with similar projections and spaces, facilitating transfer of heat from the pen body into the ambient. The arrangement minimizes variations in the pen characteristics resulting from transfer of heat from the user's hand, which can become relatively more acute as the volume of air within the ink reservoir increases as a result of ink consumption.

Abstract: As applied to printer ink cartridges having a collapsible container therein, ink refilling is accomplished through the use of a clamp and filler cartridge assembly wherein a slideable cartridge sealing plug initiates and terminates the refill process, depressurizing the cartridge at refill completion, whereby upon removal of the filling apparatus, the ink jet unit automatically obtains negative pressure. Leakage is thus precluded.