JP7709870B2 - writing implements - Google Patents

Description

The present invention relates to a writing instrument. In particular, the present invention relates to a writing instrument that houses a writing body in a barrel.

Patent Document 1 discloses a writing instrument that includes a barrel, a refill that can be stored in the barrel, a support member that is assembled between the barrel and the refill, and a return spring that is disposed rearward of the support member and biases the refill rearward, and the support member is assembled at a predetermined position in the front-to-rear direction such that when the front part of the refill, which is cantilevered on the support member, vibrates due to a predetermined external force, the front part of the refill does not collide with the inner surface of the barrel or the tip opening.

This writing instrument can reduce external impacts on the refill more than ever before.

JP 2020-142369 A

In the configuration disclosed in Patent Document 1, the support member (corresponding to the annular member of the present application) can be attached to the refill (corresponding to the writing body of the present application) from the side (radial direction), and its axial attachment position can be adjusted. In other words, the support member's axial position can be easily adjusted by the user. For this reason, there is a risk that the support member may move unexpectedly in the forward/backward direction while the writing instrument is in use, making it difficult to maintain the desired effect of reducing impact to the refill.

In addition, in the configuration disclosed in Patent Document 1, the support member can be easily attached to the refill, and the support member can be easily rearranged when replacing the refill. Therefore, when replacing the refill, the user needs to remove the support member, which may cause the support member to be lost.

The present invention was made in light of the above findings, and its purpose is to provide a writing instrument in which the annular member does not move unexpectedly in the forward and backward directions, which maintains the effect of suppressing rattling of the writing body inside the barrel, and which does not require the user to remove the annular member when replacing the writing body, thereby preventing the annular member from being lost.

The writing instrument of the present invention comprises a barrel having an opening at the front end, a writing body housed in the barrel, and an annular member attached to the inner surface of the barrel, the writing body having a pen tip and an ink reservoir tube containing ink therein, the barrel comprising at least a front barrel having the opening through which the pen tip protrudes, and a rear barrel removably screwed to the front barrel, the annular member being attached to the rear of the front barrel, and the writing body being loosely inserted into the annular member.

According to the present invention, the annular member is attached to the rear of the front shaft, and the writing body is loosely inserted into the annular member, so that the annular member does not move unexpectedly in the forward and backward directions, and the effect of suppressing rattling of the writing body inside the barrel can be maintained. In addition, when replacing the writing body, the user does not need to remove the annular member, and loss of the annular member can be prevented.

The writing instrument is preferably a retractable writing instrument that accommodates the writing body in the barrel so that it can move forward and backward, accommodates a spring that urges the writing body backward in the front barrel, and is equipped with a retractable mechanism that moves the writing body forward against the backward urging of the spring, thereby causing the pen tip to protrude from the opening.

In the present invention, the structure of the writing instrument is not important, and may be a capped writing instrument with a cap that covers the pen tip, or a retractable writing instrument in which the writing body moves back and forth within the barrel and appears and disappears from the front end opening of the barrel. However, the above-mentioned effects of the present invention can be more effectively enjoyed by using a retractable writing instrument in particular.

Preferably, the ink reservoir tube is made of a metal pipe. This allows the ink reservoir tube to be made thinner, allowing it to hold more ink.

According to the present invention, the annular member does not move unexpectedly in the forward and backward directions, and the effect of suppressing rattling inside the barrel of the writing body can be maintained. In addition, when replacing the writing body, the user does not need to remove the annular member, and loss of the annular member can be prevented.

1 is a schematic vertical cross-sectional view of a writing instrument according to a first embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of a main portion of FIG. 1 . FIG. 4 is a perspective view showing a state in which an annular member is attached to the rear end of the front axle. Figure 4(a) is a front view of the annular member of the writing instrument of Figure 1, Figure 4(b) is a bottom view of the annular member of Figure 4(a), and Figure 4(c) is a perspective view of the annular member of Figure 4(a). FIG. 11 is an enlarged longitudinal cross-sectional view of a main portion of a writing instrument according to a second embodiment of the present invention, showing an annular member attached to the inner surface of the rear barrel. Figure 6(a) is a front view of the annular member of the second embodiment, Figure 6(b) is a bottom view of the annular member of Figure 6(a), and Figure 6(c) is a perspective view of the annular member of Figure 6(a).

Two embodiments of the present invention will be described below with reference to the drawings. In the writing instrument 10 of this embodiment, "front" or "bottom" refers to the pen tip 121 side of the writing instrument 10, and "rear" or "top" refers to the opposite side.

First Embodiment
1 to 4 show a first embodiment of the present invention. Fig. 1 is a schematic vertical cross-sectional view of a writing instrument 10 in the first embodiment of the present invention, showing a state in which a pen tip 121 does not protrude (pen tip retracted state). In this embodiment, the writing instrument 10 is a retractable writing instrument in which a writing body moves in the front-rear direction within a barrel 11, and a pen tip 121 protrudes and retracts from a front end opening of the barrel 11, but the present invention is also applicable to a capped writing instrument equipped with a cap that covers the pen tip.

Figure 2 is an enlarged longitudinal cross-sectional view of the portion in Figure 1 where the annular member 13 is attached. Figure 3 is a perspective view showing the state in which the annular member 13 is fitted to the rear end of the front barrel 111. In other words, Figure 3 is a view showing the state of the front barrel 111 separated from the rear barrel 114 in order to replace the writing element. Figure 4(a) is a front view of the annular member 13 of the writing instrument 10 in Figure 1. Figure 4(b) is a bottom view of the annular member 13 in Figure 4(a). Figure 4(c) is a perspective view of the annular member 13 in Figure 4(a).

As shown in FIG. 1, the writing instrument 10 of this embodiment includes a barrel 11 with an opening at the front end, a writing body housed in the barrel 11, a ring-shaped member 13 attached to the inner surface of the barrel 11, an operating portion 16 for operating the pen tip 121 provided on the side of the barrel 11 to extend and retract, and a spring 14 for urging the writing body backward.

The writing body includes a pen tip 121, an ink reservoir 122 that contains ink, and a holder 123 that connects the pen tip 121 and the ink reservoir 122. The barrel 11 includes a front barrel 111 that has an opening through which the pen tip 121 protrudes, and a rear barrel 114 that is detachably screwed onto the front barrel 111. The writing instrument 10 of this embodiment includes a crown that is attached to the rear of the rear barrel 114, and a soft member 15 that is inserted into the crown. The annular member 13 is attached to the rear of the front barrel 111, and the writing body is loosely inserted into the annular member 13.

- Retractable writing instrument As shown in Figure 1, the writing instrument 10 of this embodiment is a retractable writing instrument that houses the writing body in a barrel 11 so that it can move back and forth, houses a spring 14 that urges the writing body backward in a front barrel 111, and is equipped with a retractable mechanism that moves the writing body forward against the backward urging of the spring 14, thereby causing the pen tip 121 to protrude from the opening.

The retractable writing instrument of this embodiment has a side-slide mechanism that uses a rotating cam mechanism. It is made up of a cam portion formed on the inner surface of the rear barrel 114, a rotating member that engages with the cam portion and abuts against the rear end of the writing body, an operating portion 16 that engages with the rotating member and protrudes radially outward from a slide hole on the side of the rear barrel 114, and a spring 14 (e.g., a compression coil spring) that is housed in the barrel tube 11 and biases the writing body 12 rearward. The retractable writing instrument of this embodiment has a double knock mechanism in which the operating portion 16 slides forward for both the pen tip extension operation and the pen tip retraction operation.

1 to 3, barrel 11 is made up of front barrel 111 having an opening at its front end through which pen tip 121 protrudes, and rear barrel 114 which is detachably screwed onto front barrel 111. In this embodiment, front barrel 111 and rear barrel 114 are cylindrical bodies with open ends that are manufactured by injection molding or extrusion molding of synthetic resin.

The front shaft 111 has an opening at its front end through which the pen tip 121 protrudes, and a male threaded portion 112 at its rear that screws into a female threaded portion 115 of the rear shaft 114. The rear end of the front shaft 111 also has a fitting portion 113 to which the annular member 13 described below is attached (fitted). The fitting portion 113 is provided on the inner surface of the rear end of the front shaft 111, and is press-fitted into the front shaft fitting portion 131 of the annular member 13. In this embodiment, the fitting portion 113 has a circumferential smooth fitting surface, but may also have a circumferential inward projection or recessed groove.

The fitting portion 113 of the front shaft 111 may be provided on the outer surface of the rear end of the front shaft 111. In that case, the front shaft fitting portion 131 of the annular member 13 is provided on the inner surface of the annular member 13. Even when the fitting portion 113 of the front shaft 111 is provided on the outer surface of the rear end of the front shaft 111, the fitting portion 113 may be provided with a circumferential smooth fitting surface, or may be provided with a circumferential outward protrusion or recessed groove.

Annular Member The annular member 13 of this embodiment includes a front shaft fitting portion 131 that fits with the inner surface of the rear end of the front shaft 111, and a guide portion 134 in front of the front shaft fitting portion 131. The annular member 13 also includes a through hole 133 that penetrates in the front-to-rear direction, and a flange portion 135 that abuts against the rear end of the front shaft 111, and a chamfered region 132 is provided at the rear end of the through hole 133.

In addition, in the writing instrument 10 of this embodiment, the writing body 12 is loosely inserted through the through hole 133. In other words, the outer diameter of the writing body 12 is smaller than the inner diameter of the through hole 133. In this embodiment, the outer diameter of the writing body 12 (ink reservoir 122) is φ6.1 mm, and the inner diameter of the through hole 133 of the annular member 13 is φ6.3.

In this embodiment, the front shaft fitting portion 131 of the annular member 13 has a circumferential smooth fitting surface, but may also have a circumferential outward protrusion or inner hole protrusion. When the fitting portion 113 of the front shaft 111 is provided on the outer surface of the rear end of the front shaft 111, the front shaft fitting portion 131 of the annular member 13 is provided on the inner surface of the annular member 13. In this case, the front shaft fitting portion 131 of the annular member 13 may have a circumferential smooth fitting surface, or may have a circumferential inner hole protrusion or recessed groove. The front shaft 111 and the annular member 13 may also be integrally formed by bonding or two-color molding.

In addition, in the annular member 13 of this embodiment, as shown in FIG. 2, a chamfered region 132 is provided around the entire circumference of the rear end of the through hole 133. It is preferable that the radial width of the chamfered region 132 is in the range of 0.1 mm to 2.0 mm, and the inclination angle θ in the cross section including the central axis of the through hole 133 is in the range of 10° to 60°. In this embodiment, the radial width is 0.6 mm, and the inclination angle θ is 30°.

The annular member 13 in this embodiment is made of polypropylene. However, the material of the annular member 13 used in the present invention is not limited to resin (e.g., polypropylene, polyacetal, polycarbonate, polyethylene), and may be metal (e.g., brass, stainless steel).

Cursive Writing Body The cursive writing body 12 in this embodiment comprises a pen tip 121, an ink housing tube 122 containing ink therein, a holder 123 connecting the pen tip 121 and the ink housing tube 122, thermochromic ink filled in the ink housing tube 122, and a follower (e.g., a high-viscosity fluid) filled at the rear end of the thermochromic ink and moving forward as the thermochromic ink is consumed.

The pen tip 121 is, for example, a metallic ballpoint pen tip that rotatably holds a ball at its front end. A tail plug with an air hole that allows ventilation between the ink reservoir 122 and the outside is attached to the rear end opening of the ink reservoir 122. A spring that presses the ball at the front end forward is housed inside the pen tip 121. The spring is a compression coil spring with a rod portion at the front end, and the front end of the rod portion is in contact with the rear surface of the ball. When not writing, the forward bias of the spring brings the ball into close contact with the inner surface of the inward-facing front edge portion of the front end of the ballpoint pen tip, preventing ink leakage from the front end of the pen tip 121 and ink evaporation.

In this embodiment, the ink reservoir 122 is made of a metal pipe using stainless steel (specifically, SUS304). The material of the ink reservoir 122 used in the present invention is not limited to metal, and may be resin (e.g., polypropylene, polyethylene).

1, when the writing instrument 10 is a thermochromic writing instrument having thermochromic ink therein, it may further include a soft member 15. The soft member 15 rubs the handwriting of the thermochromic ink, and the frictional heat generated at that time can thermally discolor the handwriting of the thermochromic ink.

The elastic synthetic resin constituting the soft member 15 is preferably made of a low-wear elastic material that generates almost no wear debris (eraser debris) during friction, rather than a high-wear elastic material (such as an eraser).

The elastic material constituting the soft member 15 is preferably, for example, a synthetic resin (rubber, elastomer) having elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butylene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, ethylene propylene diene rubber (EPDM), or a mixture of two or more types of rubber elastic materials, and a mixture of a rubber elastic material and a synthetic resin.

Ink In this embodiment, the ink contained in the writing body 12 (ink reservoir 122) is a thermochromic ink. The thermochromic ink is preferably a reversible thermochromic ink. The reversible thermochromic ink may be of various types, such as a heat-discoloring type that is decolorized by heating from a colored state, a color memory-retaining type that alternately retains a colored state or a decolored state in a specific temperature range, or a heat-coloring type that is colored by heating from a decolored state and returns to the decolored state by cooling from the colored state, either alone or in combination.

As a coloring material contained in the reversible thermochromic ink, for example, a reversible thermochromic pigment in which a reversible thermochromic composition containing at least the three essential components of (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the reaction (coloring reaction) in which the two chemically bind together occurs is encapsulated in a microcapsule is preferably used.

The ink used in the present invention is not limited to thermochromic ink, and other ink compositions can be used. For example, writing ink, correction fluid, liquid glue, cosmetic liquid, etc. may be appropriately selected depending on the application of the liquid ejection device. There is no particular limitation on writing ink, such as oil-based ink or water-based ink.

Second Embodiment
A second embodiment of the present invention is shown in Figures 5 and 6. Figure 5 is an enlarged longitudinal sectional view of a main part of a writing implement in the second embodiment of the present invention, showing an annular member 23 fitted to the inner surface of a rear barrel 114. Figure 6(a) is a front view of the annular member 23 in the second embodiment. Figure 6(b) is a bottom view of the annular member 23 in Figure 6(a). Figure 6(c) is a perspective view of the annular member 23 in Figure 6(a).

The writing instrument of this embodiment is a modified version of the first embodiment, and differs from the first embodiment in that the annular member 23 fits into the rear barrel 114 and the shape of the annular member 23 is different. The other configurations of the second embodiment are substantially the same as those of the first embodiment, so detailed descriptions thereof will be omitted.

Annular member The annular member 23 of this embodiment includes a rear axle fitting portion 231 that fits with the inner surface of the rear axle 114, and a guide portion 234 axially outward of the rear axle fitting portion 231. The rear axle fitting portion 231 and the guide portion 234 are provided on at least one outer surface of the annular member 23. The annular member 23 also includes a through hole 233 that penetrates in the front-rear direction, and a chamfered region 232 is provided on at least one end of the through hole 233. In other words, when the rear axle fitting portion 231 and the chamfered region 232 are provided on both ends of the annular member 23, the annular member 23 can be made symmetrical in the front-rear direction. This eliminates the directionality of the parts, improving assembly.

In this embodiment, the rear axle fitting portion 231 is provided with a circumferentially formed concave groove, but it may also be a circumferentially formed outward protrusion or a circumferentially smooth surface. Note that in this embodiment, the fitting portion 116 of the rear axle 114 is a circumferentially formed inward protrusion. The inner hole protrusion also serves the function of preventing the rotating member of the retraction mechanism from falling off the rear axle 114.

The writing instrument 10 configured as described above operates as follows.

According to this embodiment, the annular member 13 is press-fitted (fitted, engaged) into the rear of the front shaft 111, and the writing body 12 is loosely inserted into the annular member 13. This ensures that the annular member 13 is securely fixed to the rear of the front shaft 111 and does not move unexpectedly in the front-rear direction. This also maintains the effect of suppressing rattling of the writing body 12 inside the barrel 11. Furthermore, when replacing the writing body 12, the user does not need to remove the annular member 13, which prevents the annular member 13 from being lost.

The writing instrument 10 of this embodiment is a retractable writing instrument. According to this embodiment, the writing body 12 is loosely inserted into the annular member 13, so that even if the writing body 12 of the retractable writing instrument moves back and forth within the barrel 11, the annular member 13 is press-fitted (fitted, engaged) into the rear of the front barrel 111 and does not move back and forth. In other words, applying this invention to a retractable writing instrument can more significantly enjoy the above-mentioned effects of the invention. However, the same action and effect can be achieved with a capped writing instrument equipped with a cap that covers the pen tip.

In addition, in general, ink reservoir tubes made of metal pipes can have a thinner wall thickness. As a result, ink reservoir tubes 122 made of metal pipes can hold more ink than ink reservoir tubes made of plastic pipes (when the outer diameter of the ink reservoir tubes is approximately the same).

On the other hand, increasing the amount of ink stored by using an ink reservoir 122 made of a metal pipe results in a relatively increased weight of the writing body 12 compared to a writing body equipped with an ink reservoir tube made of a plastic pipe of the same outer diameter.

As a result, the writing body 12, which is equipped with an ink reservoir 122 made of a metal pipe, is more likely to vibrate when subjected to external vibrations, and may rattle significantly inside the barrel 11.

Therefore, by applying the present invention to a writing instrument equipped with a writing body 12 in which the ink reservoir 122 is a metal pipe, the above-mentioned effects of the present invention can be more significantly achieved even when a heavy writing body 12 is used. However, the same action and effect can be achieved even if the ink reservoir 122 is a plastic pipe.

In one aspect of this embodiment, the annular member 13 includes a front shaft fitting portion 131 that fits with the inner surface of the rear end of the front shaft 111. This eliminates the need to reduce the inner diameter of the front shaft 111, making it easier to provide a draft angle on the inner surface of the front shaft 111 and facilitating molding of the front shaft 111.

The annular member 13 also has a through hole 133 that penetrates in the front-rear direction, and a flange 135 that abuts against the rear end of the front shaft 111. This allows the annular member 13 to be easily and reliably attached to the front shaft 111. As a result, rattling of the writing body 12 within the barrel 11 can be reliably suppressed.

A chamfered area 132 is provided at the rear end of the through hole 133. This prevents damage to the pen tip 121 caused by the pen tip 121 hitting the end face (brim portion 135) of the annular member 13 when replacing the writing element 12. It also makes it easier to insert the writing element 12 into the front shaft 111 (annular member 13). Furthermore, the annular member 13 is provided with a guide portion 134 in front of the front shaft fitting portion 131, which makes it easier to insert the annular member 13 into the front shaft 111 and improves assembly.

In one aspect of this embodiment, the annular member 23 includes a rear barrel fitting portion 231 that fits with the inner surface of the rear barrel 114. In other words, the annular member 23 is housed in the inner surface of the rear barrel 114. This prevents the user from coming into contact with the annular member 23 when replacing the writing element 12, thereby preventing the annular member 23 from coming off and being lost.

The annular member 23 also has a through hole 233 that penetrates in the front-rear direction, and at least one end of the through hole 233 is provided with a chamfered area 232. In other words, when the rear axle fitting portion 231 and the chamfered area 232 are provided at both ends of the annular member 23, the annular member 23 can be made symmetrical in the front-rear direction. This eliminates the directionality of the parts, improving assembly. In addition, when replacing the writing body 12, it becomes easy to insert the writing body 12 into the rear axle 114 (annular member 23). In addition, by providing the annular member 23 with a guide portion 234 on the axially outer side of the rear axle fitting portion 231, it becomes easy to insert the annular member 23 into the rear axle 114, improving assembly.

10 Writing instrument 11 Barrel 111 Front shaft 112 Male threaded portion 113 Fitting portion 114 Rear shaft 115 Female threaded portion 116 Fitting portion 12 Writing body 121 Pen tip 122 Ink reservoir tube 123 Holder 13 Annular member 131 Front shaft fitting portion 132 Chamfered area 133 Through hole 134 Guide portion 135 Flange portion 14 Elastic body 15 Soft member 16 Operation portion 23 Annular member 231 Rear shaft fitting portion 232 Chamfered area 233 Through hole 234 Guide portion

Claims (3)

a barrel having an opening at a front end;
A writing body accommodated in the barrel;
an annular member attached to the inner surface of the barrel;
The writing instrument includes a pen tip and an ink reservoir tube that contains ink therein;
The barrel comprises at least a front barrel having the opening through which the pen tip projects, and a rear barrel detachably screwed to the front barrel,
The annular member is fitted onto an inner surface of a rear end of the front shaft,
The writing body is loosely inserted into the annular member.
The writing instrument according to claim 1, wherein the annular member comprises a front shaft fitting portion that fits with the inner surface of the rear end of the front shaft, a through hole that penetrates in the front-to-rear direction, and a flange portion that abuts against the rear end of the front shaft, and a chamfered area is provided at the rear end of the through hole.
a barrel having an opening at a front end;
A writing body accommodated in the barrel;
an annular member attached to the inner surface of the barrel;
The writing instrument includes a pen tip and an ink reservoir tube that contains ink therein;
The barrel comprises at least a front barrel having the opening through which the pen tip projects, and a rear barrel detachably screwed to the front barrel,
The annular member is fitted to an inner surface of the rear axle ,
The annular member includes a rear axle fitting portion that fits with an inner surface of the rear axle and a through hole that penetrates in the front-rear direction,
At least one end of the through hole is provided with a chamfered area ,
The writing body is loosely inserted into the annular member.