Writing ball, method for manufacturing writing ball, and ballpoint pen with writing ball
AssigneeKabushiki Kaisha Pilot Corporation
InventorKouichi Takayama
Life of this patent
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Abstract
A writing ball capable of suppressing wear of a ball seat of a ballpoint pen tip and obtaining stable ink outflow, 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.
Claims12
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.
A method for manufacturing a writing ball, the method comprising:
- a sphere forming step of forming a sphere including at least a first hard component containing a first metal, a second hard component containing a second metal, and a binding component;
- a surface treatment step of performing a surface treatment on the sphere that has been formed;
- and
- an etching step of etching the sphere subjected to the surface treatment using a solution that dissolves the second hard component but does not dissolve the first hard component.
Dependencies are inferred from the claim text.