JP2001347790A - mechanical pencil - Google Patents

Abstract

(57) [Summary] [Object] It is possible to provide a mechanical pencil that can easily identify a core color and has excellent display properties. [Structure] In a knock mechanical pencil in which a chuck is fixed to the front of a resin core case, a shaft cylinder is provided transparently, and a porous fired core body is impregnated with a dye or pigment ink in the core case. In addition to the built-in colored sharp core which makes it easy to erase the writing lines with the eraser, the eraser attached to the rear end of the lead case is provided in the same color as the color written with the colored sharp core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a knock mechanical pencil using a colored sharp core.

[0002]

2. Description of the Related Art A shaft joint is provided at the rear end of a chuck.
A so-called lead cartridge type mechanical pencil in which a lead case is detachably fastened to the rear end of the shaft coupling is known. Conventional pencil leads can be roughly classified into the following four types of manufacturing methods, but when used as a colored sharp lead, all have drawbacks. That is,

[0003] (1) A fired pencil lead obtained by kneading, molding, and then firing the mixture, which comprises graphite as a coloring agent, an organic substance, clay or the like as a binder. The pencil lead obtained by this method has recently reached a sufficient practical strength even for a pencil lead, and is known as a pencil lead that can be erased with an eraser. However, there is a drawback that a pencil lead other than black cannot be manufactured due to the colors of graphite and calcined carbon material used.

(2) A non-fired pencil lead obtained by kneading and molding a wax, a binder, a filler, a pigment, and the like. According to this production method, various kinds of organic pigments can be used, light resistance and weather resistance are good, and a color pencil lead having a vivid hue can be obtained. However, this colored pencil core is not fired and relies mainly on bonding with an organic binder. Therefore, when it is used as a mechanical pencil lead, sufficient strength cannot be obtained, and since it contains waxes, it cannot be erased with an eraser. There are drawbacks that cannot be made.

(3) Water- and oil-repellent substances, binders, body materials,
A non-fired pencil lead obtained by kneading and molding a pigment or the like, and further impregnating the open pores formed around the water / oil repellent substance with oils and fats.
According to this production method, when a liquid oil or the like at room temperature is selected as the oils and fats to be impregnated, it is possible to produce a colored pencil lead that can be easily erased with an eraser to the same extent as in (1) above. However, in the case of using a color pencil lead of a vivid hue using an organic pigment, a binder that can be used is limited to an organic polymer substance or the like due to the heat resistance of the pigment, and thus a fine lead such as for a mechanical pencil is used. In this case, there is a disadvantage that sufficient strength cannot be obtained.

(4) A pencil lead obtained by impregnating a light-colored or white fired porous pencil lead obtained by kneading, molding and firing boron nitride, clay, an organic substance and the like with a dye ink.
The line drawn by the pencil lead obtained by this method can be erased with an eraser. However, since clay is used as the binder, the strength is not sufficient as compared with the core of the above (1).

[0007] As an improvement of (4), by kneading, extruding and baking in a non-oxidizing atmosphere a compounded composition containing at least a body material and an organic excipient, the organic excipient is carbonized. Forming a first fired core using the obtained carbide as a binder, and heating the first fired core in an oxidizing atmosphere to form a second fired core made of at least a constitutional material by oxidizing and removing the binder of the carbide; Then, a perhydropolysilazane-containing liquid is impregnated in the pores of the second fired core, and silicon nitride is generated by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. And a high-strength fired sharp core obtained by coloring the third fired core with a coloring agent having excellent light resistance and weather resistance is obtained. In the obtained third fired core, silicon nitride as a binder is finely and uniformly dispersed in the core, and is generated. Further, since the body material is highly oriented, a small amount of silicon nitride is generated. It is easy to develop the strength of the core, and the collapse of the core during writing is uniform.

[0008] However, although the colored sharp core has reached a practical level, the strength of the core and the erasability with an eraser are not sufficient as compared with the black sharp core. Also, there is a problem of how easy to classify as a mechanical pencil, such as the difference between the color tone of the core itself and the written color tone and the differentiation of similar colors.

[0009]

SUMMARY OF THE INVENTION The present invention makes it possible to provide a mechanical pencil which is easy to identify the core color and has excellent display properties.

[0010]

The present invention has the following arrangement to achieve the above object. The mechanical pencil according to claim 1 is a knock mechanical pencil in which a chuck is fixed to the front of a resin core case, wherein a shaft cylinder is provided transparently, and a porous fired core body is provided in the core case. It has a built-in colored sharp core that can be easily erased by writing with an eraser by impregnating dye or pigment ink, and an eraser attached to the rear end of the core case is provided in the same color as the color written with the colored sharp core Become.

[0011]

Embodiments will be described with reference to the drawings.
FIG. 1 shows a mechanical pencil of a knocking type according to a first embodiment of the present invention. A chuck 5 has a fastener 7 loosely fitted to an outer peripheral portion of a distal end thereof, and then is inserted into a chuck insertion hole of the barrel 1 from a rear end side. The locking portion 6 on the outer periphery of the rear end portion is a core case 8
It is locked in a connection hole provided in the shaft portion 12 at the tip.

A spring 1 is provided between the core case 8 and the shaft cylinder 1.
5 is stretched, the fastener 7 abuts on the tip of the barrel 1, closes the chuck 5, and grips the sharp core 16. Shaft cylinder 1
Is a transparent resin molded product, and a base 2 to which a tip pipe 3 is fixed at the tip is screwed to a forward end thereof.

By the way, the lead case 8 is provided with the chuck 5
A shaft joint portion 11 made of a transparent resin molded product having a shaft portion 12 for locking the rear end portion, and a cylindrical portion 9 made of a colored resin molded product fixed at a joint portion 14 at the rear end. Have been. A colored sharp lead is built in the lead case 8, and the tubular portion 9 has the same color as the color written with the colored sharp lead. In addition, although the tubular portion 9 makes the built-in core 17 invisible, the presence can be confirmed from the transparent portion 13 of the shaft joint portion 11. Further, the core case 8 is formed by crimping the cylindrical portion 9 and the shaft joint portion 11 to each other, but may be formed by double molding.

FIG. 2 shows a second embodiment. Hereinafter, only differences from the first embodiment will be described. The core case 18 is a transparent resin molded product, and the other area except the one area (transparent part 20) is painted in the same color as the color written with the colored sharp core.

FIG. 3 shows a third embodiment. Hereinafter, only differences from the above embodiment will be described. The lead case 22 is formed of a resin molded product of the same color as that of the color written with a colored sharp lead, and is detachably fastened to the outer periphery of the rear end of the shaft joint 24. An opening / closing part is provided at the tip of the core case part so that the built-in core does not fall off. When the core case part is attached to the shaft joint, the opening / closing part opens so that the core is inserted into the chuck part. It is also possible to provide joints.

FIG. 4 shows a fourth embodiment. Hereinafter, only differences from the above embodiment will be described. The fourth embodiment is basically the same as the third embodiment. In this case, the core case 26 detachably fastened to the outer peripheral portion of the rear end of the shaft coupling 24 is a transparent resin molded product. Area (transparent part 27)
Other areas are painted (colored portion 28) in the same color as the color written with the colored sharp core.

As a fifth embodiment, a colored sharp lead which can be easily erased with an eraser is incorporated in the lead case. An eraser is usually attached to the rear end of the core case. If the eraser has the same color as that of the color written with a colored sharp core, the eraser is not conspicuous when erased, and the display performance is improved.

[0018]

When the barrel is made transparent and the core case is colored the same as the color written on the core, the difference between the color tone of the core itself and the written color tone and the differentiation between similar colors can be easily identified. Also, it has excellent display properties. If one area of the lead case is made transparent, the presence of the lead can be confirmed.

If the lead case is made detachable from the shaft coupling, a combination of a colored sharp lead and an eraser with good erasability for the lead can be specified, and a combination of a chuck mechanism suitable for the properties of the lead can be specified. Can be specified. In addition, since the replenishment of the core alone is not performed as a specific unit, it is not necessary to pick a fragile core with a finger and insert the core into the core case at the time of replenishing the core, thereby eliminating the problem of breakage of the core. Therefore, it is possible to solve the problem that the strength of the lead and the erasability of the eraser are not sufficient when a colored sharp lead is mounted on an arbitrary mechanical pencil.

[0020]

The construction and operation of the mechanical pencil according to the present invention are as described above. The mechanical pencil is made by impregnating a porous fired core with a dye or pigment ink so that writing lines can be easily erased with an eraser. In this case, it is possible to provide a mechanical pencil that can easily identify the core color and has excellent display properties.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a first embodiment according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of a second embodiment.

FIG. 3 is a longitudinal sectional view of a main part of a third embodiment.

FIG. 4 is a longitudinal sectional view of a main part of a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Base 3 Tip pipe 4 Holding chuck 5 Chuck 6 Locking part 7 Fastener 8 Core case 9 Tube part 10 Coloring part 11 Shaft joint part 11a Core guide 12 Shaft part 13 Transparent part 14 Joining part 15 Spring 16 Sharp core 17 Built-in core 18 Core case 18a Core guide 19 Shaft part 20 Transparent part 21 Colored part 22 Core case 23 Colored part 24 Shaft joint 24a Core guide 25 Shaft part 26 Core case 27 Transparent part 28 Colored part

Claims (1)

[Claims] 1. A knock-type mechanical pencil in which a chuck is fixed in front of a resin core case, a shaft cylinder is provided transparently, and a porous fired core body is provided with a dye or pigment ink in a core case. With a built-in colored sharp core that allows impregnated and erased writing lines easily with an eraser,
A mechanical pencil characterized in that the eraser attached to the rear end of the core case is provided in the same color as the color written with a colored sharp core.