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AssigneeMitsubishi Pencil Company, Limited
InventorsToru Kitao, Hiroyuki Muto
Estimating the term…
There is provided a ballpoint pen tip that minimizes thin spots such as impact thin spots even if upward writing or an impact causes entry of air, allows rapid return to normal writing, and minimizes manufacturing costs. A writing ball and a check ball included in the ballpoint pen tip are placed close to each other with a slight clearance therebetween to leave an inner space with a slight capacity. Thus, even if air enters from a caulking portion, the volume of the air stored inside is slight, and an air pool can be rapidly eliminated. Further, both the writing ball and the check ball can be provided in a front end of the ballpoint pen tip, and assembly operations can be easily performed without inverting the ballpoint pen tip.
A ballpoint pen tip comprising a writing ball and a check ball, the writing ball and the check ball being placed close to each other with a clearance therebetween, said clearance being such that the check ball moves away from and separates from the writing ball when a tip end of said ballpoint pen tip is directed upward and moves toward and comes into contact with the writing ball when the tip end of said ballpoint pen tip is directed downward.
A ballpoint pen comprising:
A method of manufacturing a ballpoint pen tip, comprising the steps of:
Dependencies are inferred from the claim text.