Patent Number: 8,714,856

Title: Ballpoint pen tip, ballpoint pen refill, ballpoint pen, and method of manufacturing ballpoint pen tip

Abstract: Provided are a ballpoint pen tip which can, even if ink having properties which assures that the amount of supply of the ink to the pen tip by shear of a writing ball is sufficient is adopted, prevent partially faint written traces from occurring and provide smooth writing, a ballpoint pen refill, a ballpoint pen, and a method of manufacturing a ballpoint pen tip. A triangular pyramid-shaped recess (42) gradually tapered toward an ink guide hole (36) is provided in the bottom of a ball housing (31), and troughs (44) formed in the recess (42) are utilized as ink reservoirs and ink paths. Because the troughs (44) have sufficient length, width, and depth, the amount of containment of the ink and the amount of supply of the ink are increased. Also, even if ink which is supplied to the pen point mainly by shear of a writing ball (2A) is adopted, the supply of the ink to the pen point is not interrupted, the occurrence of partially faint written traces of ink is sufficiently prevented, and friction between the writing ball and a ball receiving seat surface can be reduced.

Inventors: Ishii; Yoshihide (Yokohama, JP)

Assignee: Mitsubishi Pencil Company, Limited

International Classification: B43K 7/10 (20060101)

Expiration Date: 5/06/12018