JP7828642B2 - Retractable ballpoint pen - Google Patents

Description

This invention relates to a retractable ballpoint pen, and more specifically, to a retractable ballpoint pen in which a rotating pipe holding the refill inside a transparent barrel rotates each time the retractable mechanism is clicked, allowing the user to enjoy the changing characters or images printed on the rotating pipe.

Most retractable ballpoint pens feature a so-called "knock cam" mechanism. The refill is pushed out with a knock, and when the finger is released from the lock, the refill locks in place, allowing writing. Knocking again releases the lock, retracting the refill.

This knock cam mechanism consists of a circumferential cam formed integrally with the barrel on its inner surface, a knock rod with projections on its outer surface that slide along locking grooves formed at fixed angles on the circumferential cam and is connected to the knock mechanism, and a rotor with ribs on its outer surface that slide along guide grooves formed at fixed angles on the circumferential cam and to which the end of the refill is connected. The rotor is constantly biased together with the refill by a spring wound around the refill, and the inclined upper surface of the ribs is in contact with the serrated bottom surface of the knock rod. Furthermore, triangular recessed locking portions are formed between the vertical grooves of the circumferential cam.

In the above configuration, the contact relationship between the slanted surface of the sawtooth-shaped base of the knocking rod and the slanted surface of the rib creates a force that constantly attempts to rotate the rotor in one direction. When the knocking rod is pressed down in this state, the rotor is pushed down, causing its rib to disengage from the vertical groove. The rotor then rotates, causing the head of the rib to slide along the slanted surface of the locking mechanism, locking into place and maintaining the exposed state of the refill tip, enabling writing. When the knocking operation is performed again, the rib disengages from the locking mechanism, releasing the lock. The rotor then rotates again due to the contact relationship between the slanted surfaces, causing the rib to retract into the adjacent guide groove. This causes the rotor to rise and the refill to retract.

In the case of a retractable ballpoint pen equipped with such a knock cam mechanism, the pen barrel and the circumferential cam integrally formed on its inner surface are generally made of ABS resin, while the rotor that slides against the circumferential cam is made of polyacetal resin, which has good sliding properties against the circumferential cam and is resistant to friction.

Conventionally, a rotary-type writing instrument with a display that sequentially displays information in a display window each time the knock button is pressed has been proposed. This proposed writing instrument features a display window with a convex lens in the middle of the barrel of a conventional rotary-type writing instrument, and a hollow cylindrical shaft with a transparent outer layer attached to the pawl component of the ratchet mechanism. A piece of display paper or film is inserted into the hollow layer of the shaft (Japanese Patent Publication No. 2009-126173).

In the case of the writing instrument proposed in this invention, the information displayed through the display window is printed on a label or film, which makes the process of attaching and detaching the film during assembly time-consuming. Furthermore, naturally, this invention does not envision printing the information directly onto the writing instrument components themselves.

Japanese Patent Publication No. 2009-126173

As mentioned above, conventional writing instruments that sequentially display information in a display window each time the knock button is pressed require printing on a display sheet or film, making assembly time-consuming. Furthermore, direct printing on the writing instrument components themselves is not envisioned. Therefore, the present invention aims to provide a retractable ballpoint pen in which images or characters are directly printed on an internal rotating element, allowing the printed portion to rotate with each knock operation, enabling users to enjoy the changes through the barrel. Moreover, this pen can be manufactured at a relatively low cost.

The inventors, through research and development aimed at solving the above problems, concluded that printing was necessary on the rotating element inside the shaft. Therefore, they determined that the rotating element must be made of a printable resin, and that the element driving the rotating element (circumferential cam) must be made of a resin that allows for smooth rotation. Based on these findings, the inventors completed the present invention.

In other words, the invention described in claim 1 for solving the above problem is,
It comprises a barrel with a transparent interior, a bushing that is molded separately from the barrel and fitted and fixed inside the barrel, having a guide function and a locking function, a knocking rod that slides vertically guided by the bushing, and a rotating pipe that holds the refill and is constantly biased upward by a spring wound around the tip of the refill.
The rotating pipe has a pattern and/or characters printed on it, and a rotor that slides vertically guided by the bush is integrally formed on the rotating pipe, and the rotating pipe is locked by the bush and released from the locked state each time the knocking operation is performed on the knocking rod, and rotates, and the changes in the pattern and characters that occur with the rotation can be seen through the barrel.
This is a retractable ballpoint pen characterized in that the barrel is made of ABS resin and the bushing is made of polyacetal resin.

The invention described in claim 2, which solves the above problem,
It comprises a barrel with a transparent interior, a bushing that is molded separately from the barrel and fitted and fixed inside the barrel, having a guide function and a locking function, a knocking rod that slides vertically guided by the bushing, and a rotating pipe that holds the refill and is constantly biased upward by a spring wound around the tip of the refill.
The rotating pipe has a pattern and/or characters printed on it, and a rotor that slides vertically guided by the bush is integrally formed on the rotating pipe, and the rotating pipe is locked by the bush and released from the locked state each time the knocking operation is performed on the knocking rod, and rotates, and the changes in the pattern and characters that occur with the rotation can be seen through the barrel.
This is a retractable ballpoint pen characterized in that the barrel and the rotating pipe including the rotor are made of ABS resin, and the knocking rod and the bushing are made of polyacetal resin.

The retractable ballpoint pen according to the present invention is as described above. A rotor, guided by a bushing and sliding vertically, is integrally formed with the rotating pipe. The rotating pipe is made of a material suitable for printing patterns and characters. Because patterns and characters can be printed directly onto the rotating pipe, it can be manufactured and supplied at a relatively low cost. Furthermore, by molding the bushing, which acts as a circumferential cam, separately from the barrel, it is possible to use a resin that provides good sliding properties and strength for the rotating pipe.

These are a plan view and a front view showing the configuration of one embodiment of a retractable ballpoint pen according to the present invention. This is an exploded view showing the configuration of one embodiment of a retractable ballpoint pen according to the present invention. These are cross-sectional views along line A-A and line B-B in Figure 1. These are exploded views and enlarged cross-sectional views along line C-C of the rotating element in the retractable ballpoint pen according to the present invention.

The embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. The retractable ballpoint pen according to the present invention comprises a transparent barrel 1, a bush 2 molded separately from the barrel 1 and fitted and fixed inside the barrel 1 to provide a guide and locking function, a knocking rod 3 that slides vertically guided by the bush 2, and a rotating pipe 4 that holds a refill 6 and is constantly biased upward by a spring 7 wound around the tip of the refill 6. A rotor 5 that slides vertically within the bush 2, guided by the bush 2, is integrally formed on the rotating pipe 4.

The shaft 1 is typically made of transparent or translucent ABS resin. The bushing 2 and knock rod 3, which are molded separately from the shaft 1, are made of polyacetal resin. The rotating pipe 4 and the rotor 5, which is integrally molded with it, are also made of ABS resin, similar to the shaft 1.

The reason for using these materials for each part is the need to print patterns and text on the rotating pipe 4. Specifically, the rotating pipe 4 and rotor 5 are made of printable ABS resin, while the bush 2, which the rotor 5 slides against along its inner surface, is made of polyacetal resin, which is highly resistant to friction and ensures smooth sliding of the ABS resin rotor 5. The knock rod 3, which requires frictional strength, is also made of polyacetal resin. Because the bush 2 is made of a different material than the shaft cylinder 1, it is molded separately from the shaft cylinder 1 and then pushed into the shaft cylinder 1 for fitting and fixing.

A tip cap 8 is screwed onto the end of the barrel 1, from which the tip of the refill 6 extends and retracts. A clip 9 is fitted to the rear end of the barrel 1, and a hollow knock mechanism 10 is inserted through the opening on the top of the clip 9, with the head of the knock rod 3 fitted into the hollow knock mechanism 10.

The knock rod 3 is cylindrical, and typically has three engaging protrusions 15 at fixed angular intervals on its lower outer surface. These protrusions engage with and slide into locking grooves 11 formed vertically on the inner surface of the bush 2. The bottom surface of the knock rod 3 is a serrated ring 16 (Figures 2 and 4).

The rotor 5 is formed by creating three ribs 17 on the circumferential surface of a cylindrical shaft, typically at fixed angular intervals. The head surface 17a of the ribs 17 is beveled (Figures 2 and 4). These ribs 17 engage with guide grooves 12 formed vertically on the inner circumferential surface of the bush 2 and slide vertically. Furthermore, their head surface 17a contacts the bevel of the sawtooth ring 16 on the bottom surface of the knock rod 3, and receives a rotational drive force in the lateral direction from the sawtooth ring 16, as will be described later. The rotor 5 is integrally molded with the rotating pipe 4, and patterns or characters are printed on the rotating pipe 4 as appropriate. The patterns or characters may also extend to the rotor 5.

The bush 2 has substantially the same configuration and function as the circumferential cam in a conventional knock cam mechanism. Specifically, the inner circumferential surface of the bush 2 has a locking groove 11 into which the engaging projection 15 engages, and a guide groove 12 through which the rib 17 moves in and out. Furthermore, a triangular recessed locking portion 13 is formed at the bottom surface between the guide grooves 12 to lock the rib 17 (Figures 2 and 4).

In the above configuration, when the refill 6 is retracted into the tip cap 8, the rotor 5, which is integrated with the rotating pipe 4, is biased upward by the spring 7 with its rib 17 engaged with the guide groove 12, and the head surface 17a of the rib 17 is in contact with the serrated ring 16 of the knock rod 3, which is fitted into the bush 2 (Figure 3). In this state, when the knock rod 3 descends in conjunction with the knocking operation on the hollow knock 10, the rib 17 is pushed downward while engaged with the guide groove 12.

When the knocking rod 3 is pushed down to the bottom of the locking groove 11, the rib 17 disengages from the guide groove 12. Immediately, the rotor 5 and its integrated rotating pipe 4 rotate due to a lateral force from the sawtooth ring 16, causing the rib 17 to disengage from the guide groove 12. When the finger is then released from the knocking rod 10, the rotor 5 continues to rise, biased by the spring 7. However, because the rib 17 is disengaged from the guide groove 12, the head surface 17a of the rib 17 separates from the sawtooth ring 16 and contacts the inclined surface of the locking portion 13 of the bush 2. It slides along this inclined surface and locks into place at the innermost part of the locking portion 13. In this state, the refill 6 remains exposed, making writing possible.

When the knocking operation is performed again, the rib 17 moves laterally due to the action of the serrated ring 16, as described above, disengaging from the locking part 13 and reaching the guide groove 12. The spring 7's elastic force causes it to rise within the guide groove 12, resulting in the refill 6 retracting.

As described above, the rotating pipe 4 rotates in one direction each time the knocking operation is performed, and the images and characters printed on it also rotate, allowing the user to enjoy the changes that accompany this rotation through the barrel 1.

Since the refill 6 can be removed from the rotating pipe 4, it is possible to replace only the refill 6. However, in the case of the retractable ballpoint pen according to the present invention, since patterns and characters can be printed on the rotating pipe 4, it is possible to supply it at a relatively low cost. Therefore, by preparing various patterns and characters to be printed on the rotating pipe 4, it is also possible to commercialize the refill 6 and rotating pipe 4 as an integrated unit, making the rotating pipe 4, including the refill 6, a replaceable part.

The retractable ballpoint pen according to the present invention is as described above. A rotor, guided by a bushing and sliding vertically, is integrally formed with the rotating pipe. The rotating pipe is made of a material suitable for printing patterns and characters. Because patterns and characters can be printed directly onto the rotating pipe, it can be manufactured and supplied at a relatively low cost. Furthermore, by molding the bushing, which acts as a circumferential cam, separately from the barrel, the rotating pipe can be made of a resin that provides good sliding and strength, thus offering significant industrial applicability.

1. Barrel 2. Bushing 3. Knock rod 4. Rotating pipe 5. Rotor 6. Refill 7. Spring 8. Tip cap 9. Clip 10. Hollow knock 11. Locking groove 12. Guide groove 13. Locking part 15. Engaging projection 16. Serrated ring 17. Rib

Claims (2)

It comprises a barrel with a transparent interior, a bushing that is molded separately from the barrel and fitted and fixed inside the barrel, having a guide function and a locking function, a knocking rod that slides vertically guided by the bushing, and a rotating pipe that holds the refill and is constantly biased upward by a spring wound around the tip of the refill.
The rotating pipe has a pattern and/or characters printed on it, and a rotor that slides vertically guided by the bush is integrally formed on the rotating pipe, and the rotating pipe is locked by the bush and released from the locked state each time the knocking operation is performed on the knocking rod, and rotates, and the changes in the pattern and characters that occur with the rotation can be seen through the barrel.
A retractable ballpoint pen characterized in that the barrel is made of ABS resin and the bushing is made of polyacetal resin. It comprises a barrel with a transparent interior, a bushing that is molded separately from the barrel and fitted and fixed inside the barrel, having a guide function and a locking function, a knocking rod that slides vertically guided by the bushing, and a rotating pipe that holds the refill and is constantly biased upward by a spring wound around the tip of the refill.
The rotating pipe has a pattern and/or characters printed on it, and a rotor that slides vertically guided by the bush is integrally formed on the rotating pipe, and the rotating pipe is locked by the bush and released from the locked state each time the knocking operation is performed on the knocking rod, and rotates, and the changes in the pattern and characters that occur with the rotation can be seen through the barrel.
A retractable ballpoint pen characterized in that the barrel and the rotating pipe including the rotor are made of ABS resin, and the knocking rod and the bushing are made of polyacetal resin.