Ballpoint pen refill and ballpoint pen

Patent metadata

Field	Value
Publication number	US-12275271-B2
Application number	US-202218704305-A
Country	US
Kind code	B2
Filing date	Oct 19, 2022
Priority date	Oct 29, 2021
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

Provided is a ballpoint pen refill including: 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, in which 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 provided with a gap from a rear end of the compression portion.

First claim

The invention claimed is:

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.

2. The ballpoint pen refill according to claim 1 , wherein the compression portion has a bellows shape.

3. The ballpoint pen refill according to claim 2 , wherein a slit is formed rearward from the distal end of the ball holder.

4. The ballpoint pen refill according to claim 2 , wherein all members thereof, except the ink, are made of a synthetic resin.

5. A ballpoint pen storing the ballpoint pen refill according to claim 2 in a shaft tube.

6. The ballpoint pen refill according to claim 1 , wherein a slit is formed rearward from the distal end of the ball holder.

7. The ballpoint pen refill according to claim 6 , wherein all members thereof, except the ink, are made of a synthetic resin.

8. A ballpoint pen storing the ballpoint pen refill according to claim 6 in a shaft tube.

9. The ballpoint pen refill according to claim 1 , wherein all members thereof, except the ink, are made of a synthetic resin.

10. A ballpoint pen storing the ballpoint pen refill according to claim 9 in a shaft tube.

11. A ballpoint pen storing the ballpoint pen refill according to claim 1 in a shaft tube.

Assignees

• Mitsubishi Pencil Co

Inventors

• Homma Yuichiro

Classifications

• B43K1/088

  with an intermediate element between the resilient supporting means and the ball · CPC title

• B43K1/086

  with resilient supporting means for the ball, e.g. springs · CPC title

• B43K7/005

  Pen barrels · CPC title

• B43K7/10

  Arrangements for feeding ink to the ball points (B43K7/01 takes precedence) · CPC title

• B43K7/12

  with retractable ball points (mechanisms for retracting or locking ball points B43K24/00) · CPC title