| 摘要 |
PROBLEM TO BE SOLVED: To provide a duplex writing instrument of good portability and usability which is free from blots or writing scratches and protects hands, clothes and the like from getting soiled by the forward and reverse flows of ink. SOLUTION: Aqueous ball-point pen ink or oily ink of low viscosity of shear viscosity reducing properties is filled in an ink storage tube. A follower composed of a grease-like translucent non-drying material moving following the consumption of ink accompanying the writing is filled at the rear end of ink. Ink storage sections of the ink storage tube of ball-point pen writing instruments 1a and 1b are provided with comparatively large section area and undeformable, and an end of the ball is usually pressed to and brought into contact with the inner edge of a ball wrapping section at the end of a tip 10, and a spring is provided so as to release the state of being brought into contact with. A plurality of writing instruments including at least one ball-point pen writing body are fitted, and respective ends appear and disappear selectively from the end of a pen holder. |
