| 摘要 |
PROBLEM TO BE SOLVED: To obtain a low cost duplex writing utensil with a simple structure, the writing tip part of which smoothly extends and retracts even under the condition that a plurality of ballpoint pen writing bodies, the ink storage part of each of which is large-sized and non-deformable, are installed. SOLUTION: An operating body 34 is fixed to a shaft tube under the condition being rotatable within a certain range. A sliding projecting part, which is integrally provided near at the rear end of the ink storage part of a ballpoint pen writing body, is engaged with a cam slope 35, which is provided in the rear of the rib of the operating body. At the same time, each ballpoint pen writing body is provided movable only axially to the shaft tube. Further, each ink storage part is fittingly inserted in a shaft with no rocking. A flexibly bendable long front shaft part 3 is provided between the front end of the ink storage part and the writing tip part of each ballpoint pen writing body. In addition, a partitioning part, through which the front shaft parts pass, is provided properly backward from the tip part of the shaft tube. Return springs 44a and 44b are arranged between the partitioning part and the fore end of the ink storage part. By rotating the operating body to the shaft tube, respective ballpoint pen writing bodies become smoothly movable forwards and backwards. |
