US 12,275,271 B2
Ballpoint pen refill and ballpoint pen
Yuichiro Homma, Shinagawa-ku (JP)
Assigned to MITSUBISHI PENCIL COMPANY, LIMITED, Tokyo (JP)
Appl. No. 18/704,305
Filed by MITSUBISHI PENCIL COMPANY, LIMITED, Tokyo (JP)
PCT Filed Oct. 19, 2022, PCT No. PCT/JP2022/038996
§ 371(c)(1), (2) Date Apr. 24, 2024,
PCT Pub. No. WO2023/074505, PCT Pub. Date May 4, 2023.
Claims priority of application No. 2021-178197 (JP), filed on Oct. 29, 2021; and application No. 2022-076687 (JP), filed on May 6, 2022.
Prior Publication US 2024/0416674 A1, Dec. 19, 2024
Int. Cl. B43K 7/04 (2006.01); B43K 1/08 (2006.01); B43K 7/00 (2006.01)
CPC B43K 7/04 (2013.01) [B43K 1/086 (2013.01); B43K 7/005 (2013.01); B43K 1/088 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A ballpoint pen refill comprising:
an ink storage tube made of a synthetic resin and storing an ink thereinside;
a ball holder made of a synthetic resin and attached to a distal end of the ink storage tube;
a ball pressing rod mounted inside the ball holder; and
a writing ball stored in a distal end of the ball holder and having a rear end side held by the ball pressing rod,
wherein the ball pressing rod includes:
a fixing portion fixed to the ball holder;
a movable portion slidable in a front-rear direction with respect to the ball holder;
a compression portion connecting the fixing portion and the movable portion; and
a rearward movement restricting portion protruding from a distal end of the fixing portion; and
a gap between a distal end of the rearward movement restricting portion and a rear end of the movable portion.