US 12,220,937 B2
Writing ball, method for manufacturing writing ball, and ballpoint pen with writing ball
Kouichi Takayama, Tokyo (JP)
Assigned to KABUSHIKI KAISHA PILOT CORPORATION, Tokyo (JP)
Appl. No. 18/712,910
Filed by KABUSHIKI KAISHA PILOT CORPORATION, Tokyo (JP)
PCT Filed Nov. 17, 2022, PCT No. PCT/JP2022/042736
§ 371(c)(1), (2) Date May 23, 2024,
PCT Pub. No. WO2023/095713, PCT Pub. Date Jun. 1, 2023.
Claims priority of application No. 2021-192227 (JP), filed on Nov. 26, 2021.
Prior Publication US 2024/0416673 A1, Dec. 19, 2024
Int. Cl. B43K 1/08 (2006.01); B43K 7/00 (2006.01)
CPC B43K 1/082 (2013.01) [B43K 1/084 (2013.01); B43K 7/00 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A writing ball that is a sphere, the sphere comprising, at least:
a first hard component containing a first metal;
a second hard component containing a second metal; and
a binding component,
the writing ball comprising:
a first outer surface from which the first hard component is exposed, the first outer surface being an outermost surface of the sphere; and
a recess including, as a bottom surface, a second outer surface from which the second hard component is exposed, the second outer surface being recessed inward from the first outer surface,
wherein the first outer surface includes a smooth surface.