| 摘要 |
PROBLEM TO BE SOLVED: To allow slip difficulty when writing and a good feel of writing to be compatible by constituting a protrusion of a holding portion of a small protrusion having a small contact area with a holding hand and a protrusion having a large contact area. SOLUTION: A refill for mounting a tip 2 of a ballpoint pen is contained in a barrel 1. A convergent nose 3 is engaged with an end of the barrel 1, and an end of the tip 2 is projected from its end hole of the nose 3. A tail plug 4 is press injected into a rear end of the barrel 1. A plurality of protrusions are formed on an outer wall of a front side portion of the barrel 1. As the protrusions, three types of a large protrusion 5, an intermediate protrusion 6 and a small protrusion 7 according to size differences of printing areas are formed. The protrusion 5 has five times or above as large printing area as the protrusion 5. Actually, the large protrusion : the small protrusion = 30:1, and the large protrusion : the intermediate protrusion = 30:6 are set.
|
