JP2023093707A - writing instrument - Google Patents

Abstract

To provide a writing instrument free from the possibility of staining the outer surface of a barrel or damaging the outer surface of the barrel even when placed on a horizontal mounting surface when not in use.SOLUTION: The writing instrument includes a barrel 3 containing ink therein and provided with a pen tip 4 capable of ejecting the ink at the front end thereof, and a cap 8 detachably mounted to the pen tip side of the barrel 3. The diameter of the outer surface of the cap 8 is reduced toward the front. The center of gravity G of the writing instrument is positioned inside the cap 8 with the cap 8 mounted to the pen tip side of the barrel 3. When the writing instrument is placed on a horizontal mounting surface F, the outer surface of the cap 8 contacts the horizontal mounting surface F, and the outer surface of the barrel 3 behind the cap 8 is out of contact with the horizontal mounting surface F.SELECTED DRAWING: Figure 3

Description

The present invention relates to writing instruments .

Conventionally, for example, in Patent Document 1, a writing instrument body containing thermochromic ink, a cap protecting a writing part at the front end of the writing instrument body, and a cap provided at the rear end of the writing instrument body for writing with thermochromic ink and an erasing member that discolors drawn lines by frictional heat.

JP 2016-78418 A

When the writing instrument of Patent Document 1 is placed on a horizontal mounting surface such as a desk or a workbench when not in use, the outer surface of the barrel and the erasing member (corresponding to the friction portion of the present application) are placed on the horizontal mounting surface. Contact. As a result, dirt such as dust on the aqueous mounting surface may adhere to the outer surface of the barrel or the outer surface of the erasing member, or the outer surface of the barrel (for example, the decorative portion) may be damaged. In particular, when the dirty erasing member is used to rub the handwriting on the paper, the paper becomes dirty.

The present invention is intended to solve the main problem of the conventional art, and even when placed on a horizontal mounting surface when not in use, the outer surface of the barrel can become dirty or scratched. It is intended to provide a writing instrument without fear.

In the present invention, "front" refers to the pen point side of the barrel and the closing side of the cap, and "rear" refers to the tail end side of the barrel and the opening side of the cap.

A first invention of the present application consists of a barrel 3 containing ink therein and having a pen tip 4 capable of discharging the ink at its front end, and a cap detachably attached to the pen tip side of the barrel 3. 8, wherein the cap 8 includes a cylindrical cap body 81, the outer surface of the cap body 81 has a diameter-reduced portion 81a whose diameter decreases toward the front, and the barrel With the cap 8 attached to the pen tip 4 side of the barrel, the center of gravity G of the writing instrument is positioned radially inward of the diameter-reduced portion 81a of the cap main body 81, and the cap 8 is attached to the pen tip 4 side of the barrel. When the writing instrument is placed on the horizontal placement surface F with the is attached, the diameter-reduced portion 81a of the cap body 81 comes into contact with the horizontal placement surface F, and the shaft cylinder 3 behind the cap 8 It is required that the outer surface be in a non-contact state with the horizontal mounting surface F.

Due to the above configuration, the writing instrument 1 of the first invention is not in use, and even if it is placed on the horizontal placement surface F with the cap 8 attached to the pen tip side, the outer surface of the barrel 3 is dirty. and the outer surface of the barrel 3 is not damaged. Further, since the outer surface of the cap 8 whose diameter is reduced toward the front comes into contact with the horizontal mounting surface F, the axis C of the writing instrument 1 rises from the horizontal mounting surface F toward the rear (that is, the horizontal mounting surface F ), the outer surface of the shaft tube 3 behind the cap 8 can easily be brought into a non-contact state with the horizontal mounting surface F.

A second invention of the present application is a writing instrument according to the first invention, in which the outer surface of the barrel 3 behind the cap 8 is positioned rearward in a state in which the cap 8 is attached to the pen tip 4 side of the barrel 3. The outer surface of the barrel 3 is provided with a decorative portion, and the writing instrument is placed on the horizontal mounting surface F with the cap 8 attached to the pen point 4 side of the barrel 3. At this time, it is required that the decorative portion be in a non-contact state with the horizontal mounting surface F.

According to the second aspect of the present invention, the writing instrument 1 is free from the possibility that the decorative portion on the outer surface of the barrel 3 is soiled or the outer surface of the barrel 3 is damaged due to the above configuration.

A third invention of the present application is the writing instrument according to the first or second invention, wherein an ink-absorbing body 5 impregnated with ink is housed inside the barrel 3, and the pen point side of the barrel 3 is provided with the ink occluding body 5. It is required that a length B of 1/2 or more of the overall length A of the ink occluding body 5 is positioned inside the cap 8 when the cap 8 is attached.

The writing instrument 1 of the third aspect of the present invention can easily obtain a configuration in which the center of gravity G of the writing instrument 1 is positioned inside the cap 8 when the cap 8 is attached to the pen point side of the barrel 3. .

When the writing instrument of the present invention is not in use, even when placed on a horizontal placement surface, there is no fear that the outer surface of the barrel will become dirty or scratched.

It is a longitudinal cross-sectional view of a state in which a cap is attached to the pen tip side of the embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of a state in which a cap is removed from the shaft cylinder of FIG. 1; FIG. 2 is a vertical cross-sectional view of the thermochromic writing instrument of FIG. 1 placed on a horizontal placement surface;

A thermochromic writing instrument 1 according to an embodiment of the present invention is shown in FIGS. 1 to 3. FIG. A thermochromic writing instrument 1 of this embodiment includes a writing instrument body 2 and a cap 8 . The writing instrument main body 2 includes a barrel 3, an ink occluding body 5 accommodated inside the barrel 3, a nib 4 fixed to the front end of the barrel 3, and a friction portion fixed to the rear end of the barrel 3. 7.

Axle barrel The barrel 3 includes a cylindrical front shaft 31 and a cylindrical rear shaft 32 coupled to the rear portion of the front shaft 31 . The front shaft 31 includes a tapered portion 31a to which the pen tip 4 is fixed, a front cylindrical portion 31b integrally connected to the rear of the tapered portion 31a, and a radially outward portion from the rear end of the front cylindrical portion 31b. It has a flange portion 31c that is integrally connected so as to protrude in the direction, and a rear cylindrical portion 31d that is integrally connected to the rear of the collar portion 31c. The front shaft 31 and the rear shaft 32 are obtained from a molding of synthetic resin (for example, polypropylene or the like).

・Front Shaft A pen tip mounting hole 31e is provided through the tapered portion 31a of the front shaft 31 in the axial direction. The pen tip 4 is press-fitted and fixed to the pen tip attachment hole 31e. The ink occluding body 5 is housed inside the front barrel 31 , and the front end of the ink occluding body 5 and the rear end of the nib 4 are connected. The rear end of the ink occluding body 5 protrudes rearward from the rear end of the front shaft 31 . A contact wall portion 31f is formed behind the pen tip mounting hole 31e on the inner surface of the front barrel 31, and the front end of the ink occluding body 5 contacts the contact wall portion 31f.

- Rear shaft The rear shaft 32 has an outer surface whose diameter decreases toward the rear. The rear shaft 32 is open at both ends and has an axially penetrating inner hole. An annular seal portion 32a and a locking wall portion 32b positioned behind the annular seal portion 32a are integrally formed on the inner surface of the intermediate portion of the rear axle 32. As shown in FIG. The annular seal portion 32a and the outer surface of the inner plug 6 are airtightly fitted in the radial direction, and the locking wall portion 32b and the rear end of the inner plug 6 are brought into contact with each other in the axial direction. The friction portion 7 is press-fitted and fixed to the rear end opening of the rear axle 32 . The inner surface of the front portion of the rear axle 32 and the outer surface of the rear cylindrical portion 31d of the front axle 31 are fixed by airtight fitting. The outer surface of the rear axle 32 is provided with a decorative portion by transfer printing.

- Pen tip The pen tip 4 is a resin-processed body of a synthetic resin (for example, polyester) fiber bundle. The pen tip 4 has a chisel-like (chisel-like) front end. The rear end of the pen tip 4 has a tapered surface whose diameter decreases toward the rear. The rear end of the pen tip 4 is pierced and connected to the front end of the ink absorbing body 5 .

Ink occluding body The ink occluding body 5 is composed of a synthetic resin fiber bundle (for example, a polyester fiber bundle) and a cylindrical outer covering surrounding the outer periphery thereof. The outer skin is made of a synthetic resin cylindrical body (for example, a polypropylene resin extruded body). The ink occluding member 5 is impregnated with the thermochromic ink and held therein.

Thermochromic ink Thermochromic ink is one that uses a thermochromic microcapsule pigment, and includes (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) both of the above. An aqueous ink composition is employed that contains a reversible thermochromic microcapsule pigment encapsulating a reversible thermochromic composition comprising a reaction medium that determines the temperature at which color reaction occurs. Examples of the thermochromic ink include a type that decolors when heated, and a type that develops color when heated.

Inner plug The inner plug 6 is obtained by molding a synthetic resin (for example, polypropylene). The inner plug 6 is a bottomed cylindrical body with an open front end and a closed rear end. The outer surface of the inner plug 6 is airtightly fitted with the annular seal portion 32a on the inner surface of the rear barrel 32 . The rear end of the inner plug 6 is locked to the locking wall portion 32b on the inner surface of the rear shaft 32 in the axial direction. The front end of the inner plug 6 is brought into contact with the rear end of the ink occluding body 5 (the rear end of the outer skin). Airflow between the rear end opening of the rear barrel 32 and the inside of the rear barrel 32 is blocked by the inner plug 6 .

Friction Portion The friction portion 7 includes a cylindrical small-diameter portion 71 and a convex curved large-diameter portion 72 integrally connected to the rear of the small-diameter portion 71 . The small-diameter portion 71 is press-fitted and fixed to the rear end opening of the rear axle 32 , and the large-diameter portion 72 protrudes rearward from the rear end of the rear axle 32 . The maximum outer diameter of the portion (large-diameter portion 72 ) protruding rearward from the rear end of the rear axle 32 is set equal to or smaller than the outer diameter of the rear end of the rear axle 32 .

Examples of the material forming the friction portion 7 include synthetic resins (rubber, elastomer) having elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene -butadiene-styrene copolymer), fluorine-based resins, chloroprene resins, nitrile resins, polyester-based resins, olefin-based resins, ethylene propylene diene rubber (EPDM), and the like. The friction portion 7 is made of a low-wear elastic material that does not generate abrasion debris during friction, rather than a high-wear elastic material (eg, an eraser, etc.). The friction portion 7 can also be formed integrally with the barrel 3 (rear barrel 32) by two-color molding. Alternatively, the entire barrel 3 (the entire rear barrel 32) may be integrally formed of elastic synthetic resin, and the friction portion 7 may be provided at the rear end of the barrel 3 (the rear end of the rear barrel 32).

The cap 8 includes a cylindrical cap main body 81 , a clip 81 b integrally formed on the outer surface of the cap main body 81 , and a seal cylinder 82 fixed inside the cap main body 81 .

The outer surface of the cap main body 81 has a reduced-diameter portion 81a whose diameter is reduced toward the front (that is, the outer diameter is reduced toward the front). Examples of the shape of the reduced-diameter portion 81a include a tapered surface, a convex curved surface, and a concave curved surface. The cap main body 81 is obtained by molding a synthetic resin (for example, polycarbonate). The seal cylinder 82 is obtained by molding a synthetic resin (for example, polypropylene). The seal cylinder 82 is a bottomed cylindrical body with a closed front end and an open rear end. When the cap 8 is attached to the pen tip side, the inward protrusion 81c on the inner surface of the cap main body 81 and the outward protrusion 31g on the outer surface of the barrel 3 (the outer surface of the front barrel 31) are fitted over each other (retaining fit). At the same time, the inner surface of the seal cylinder 82 and the outer surface of the pen tip side of the barrel 3 (the outer surface of the front barrel 31) are annularly and airtightly fitted. An object such as a pocket can be held between the clip 81b and the outer surface of the cap body 81. As shown in FIG.

FIG. 3 shows a state in which the thermochromic writing instrument 1 of this embodiment is placed on the horizontal placement surface F. As shown in FIG.
When the cap 8 is attached to the pen tip side, the center of gravity G of the thermochromic writing instrument 1 as a whole is positioned inside the cap (inward in the diameter direction of the reduced diameter portion 81a). The longitudinal length B of the portion where the ink occluding body 5 is located inside the cap when the cap 8 is attached to the pen tip side is 1/2 or more (50% or more) of the total length A of the ink occluding body 5. ). When the thermochromic writing instrument 1 is placed on the horizontal placement surface F, the clip 81b contacts the horizontal placement surface F, and the diameter-reduced shape portion 81a of the outer surface of the cap 8 contacts the horizontal placement surface F, The axis C of the thermochromic writing instrument 1 is separated from the horizontal mounting surface F as it goes rearward. The outer surface of the barrel 3 (the outer surface of the rear barrel 32) and the outer surface of the friction portion 7 are out of contact with the horizontal mounting surface F. A gap D between the friction portion 7 and the horizontal mounting surface F is set to 3 mm or more.

In the thermochromic writing instrument 1 of the present embodiment, the outer surface of the cap 8 is reduced in diameter toward the front, and the center of gravity G of the thermochromic writing instrument 1 is set to Positioned inside the cap 8, when the thermochromic writing instrument 1 is placed on the horizontal placement surface F with the cap 8 attached to the pen point side of the barrel 3, the outer surface of the cap 8 is horizontally placed. The outer surface of the barrel 3 behind the cap 8 and the outer surface of the friction portion 7 come into contact with the surface F and are in a non-contact state with the horizontal mounting surface F, so that the cap 8 is attached to the pen tip side when not in use. Even if it is placed on the horizontal placement surface F in this state, the outer surface of the barrel 3 and the outer surface of the friction portion 7 will not become dirty or the outer surface of the barrel 3 will be damaged. In addition, since the outer surface (diameter-reduced shape portion 81a) of the cap 8 whose diameter is reduced toward the front comes into contact with the horizontal mounting surface F, the axis of the thermochromic writing instrument 1 moves backward from the horizontal mounting surface F. As a result, the outer surface of the shaft tube 3 behind the cap 8 and the outer surface of the friction portion 7 can easily be brought into a non-contact state with the horizontal mounting surface F.

In the thermochromic writing instrument 1 of the present embodiment, when the cap 8 is attached to the pen point side of the barrel 3, the outer surface of the barrel 3 behind the cap 8 is reduced in diameter as it goes rearward. When the thermochromic writing instrument is placed on the horizontal mounting surface F with the cap 8 attached to the pen tip side, the gap D between the friction portion 7 and the horizontal mounting surface F is set to 3 mm or more. As a result, the outer surface of the barrel 3 and the outer surface of the friction portion 7 are further prevented from being soiled or the outer surface of the barrel 3 is damaged.

In the thermochromic writing instrument 1 of the present embodiment, the ink occluding body 5 impregnated with the thermochromic ink is accommodated inside the barrel 3, and the cap 8 is attached to the pen point side of the barrel 3. A length B of 1/2 or more (50% or more) of the total length A of the ink occluding body 5 is positioned inside the cap 8, so that the cap 8 is attached to the pen point side of the barrel 3. A configuration in which the center of gravity G of the thermochromic writing instrument 1 is located inside the cap 8 in the folded state can be easily obtained.

1 thermochromic writing instrument 2 writing instrument body 3 barrel 31 front barrel 31a tapered portion 31b front cylinder 31c flange 31d rear cylinder 31e pen tip mounting hole 31f contact wall 31g outward protrusion 32 rear barrel 32a annular seal 32b locking wall 4 pen tip 5 ink occluding body 6 inner plug 7 friction portion 71 small diameter portion 72 large diameter portion 8 cap 81 cap main body 81a reduced diameter portion 81b clip 81c inward projection 82 seal cylinder A full length of ink occluding body B Length of ink occluding body located in the cap C Axis line D Gap G Center of gravity F Horizontal placement surface

Claims (3)

A writing instrument comprising: a barrel housing ink therein and having a pen tip at the front end thereof capable of ejecting the ink ; and a cap detachably attached to the pen tip side of the barrel, The cap has a cylindrical cap main body, the outer surface of the cap main body has a diameter-reduced portion whose diameter decreases toward the front, and the center of gravity of the writing instrument is positioned in a state where the cap is attached to the pen tip side of the barrel. When the writing instrument is placed on the horizontal placement surface with the cap positioned radially inward of the reduced-diameter portion of the cap body and attached to the pen tip side of the barrel, the cap body contracts. A writing instrument , wherein a diameter-shaped portion is in contact with a horizontal mounting surface, and an outer surface of the barrel behind the cap is in a non-contact state with the horizontal mounting surface. With the cap attached to the pen point side of the barrel, the outer surface of the barrel behind the cap is reduced in diameter as it goes rearward , the outer surface of the barrel includes a decorative portion, and the barrel is provided with a decorative portion. 2. The writing instrument according to claim 1, wherein when the writing instrument is placed on the horizontal mounting surface with the cap attached to the pen tip side, the decorative portion is in a non-contact state with the horizontal mounting surface. An ink occluding body impregnated with ink is accommodated in the barrel, and the length of the ink occluding body is 1/2 or more of the total length of the ink occluding body in a state where the cap is attached to the pen tip side of the barrel. 3. A writing instrument according to claim 1 or 2, wherein the tip is located inside the cap.

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