JPH04100896U - Shape pencil - Google Patents

Abstract

(57) [Summary] [Structure] A lead protection tube is placed at the tip of the barrel of a mechanical pencil whose lead lead is fed out by pressing, and an inner surface treatment such as an elastic coating is applied to the inner surface of the lead protection tube. Place the core holding member. A mechanical pencil in which a curved portion or a tapered portion is formed on at least one of the inner surface treatment portion and the inner surface of the tip or the inner surface of the rear end of the lead holding member. [Effect] Even if the writing pressure increases during writing and force is applied to the end of the lead holding member, breakage of the lead lead can be prevented as much as possible.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is installed at the tip of a mechanical pencil, etc., where a cursive character appears and retracts from the tip of the barrel. This invention relates to an improvement of a core holding member in a core protection tube.

0002

[Conventional technology]

A mechanical pencil with a lead protection tube at the tip of the barrel that holds the lead lead. Various applications have been filed. This is aimed at making effective use of lead cores, and uses lead cores as much as possible. The purpose is to hold the lead core near the protrusion. As an example, Jikko 58 -32959 publication is mentioned. To explain briefly, there is a By placing a core insertion tube (core protection tube) and laminating an elastic thin film on the inner surface of the insertion tube, the core can be protected. This is a holding part.

0003

[Problem that the idea aims to solve]

However, in the above conventional technology, an elastic thin film is laminated on the inner surface of the core protection tube. However, edges are formed on the inner surface of the tip of the core protection tube during machining. When writing, the lead may be scraped by the edge and break, or the lead may bend due to the pressure of the writing. There were cases where the lead core bit into the edge and broke.

0004

[Means to solve the problem]

This invention was devised in view of the above problems, and is provided at the tip of the shaft cylinder. At least one of the inner surface of the leading end or the inner surface of the rear end of the core holding member placed in the core protection tube The gist is that a curved portion or a tapered portion is formed on one side.

[0005]

【Example】

In FIG. 1, reference numeral 1 is a barrel of a mechanical pencil, and inside the barrel 1 is a Chuck 3 with chuck ring 2 fitted around its front outer periphery (the figure shows a three-split chuck) A chuck (generally called a ball chuck) may also be used. It is location. In addition, the tip of the shaft tube 1 is made of metal, synthetic resin, ceramics, etc. Although the core protection tube 4 is press-fitted, the shaft tube 1 and the core protection tube 4 may be integrated. Reference number 5 is a core detent member that lightly holds the core L, but it is not necessarily necessary. isn't it.

[0006] An inner surface treatment part 6 is formed on the inner surface of the core protection tube 4, and a portion 6 is formed between the inner surface of the core protection tube 4 and the inner surface of the core protection tube 4. A notch 8 made of metal, synthetic resin, etc. that has a partial gap 7 and expands and restores its shape. An annular core holding member 9 is arranged. The shape of this core holding member 9 is shown in the figure. As shown in Figure 2, the cross section is approximately triangular with rounded corners, or as shown in Figure 3. Various types can be adopted, such as one having a substantially square cross section with rounded corners. In addition, core retention In the examples of FIGS. 2 and 3, the expansion and restoration of the member 9 is achieved by the gap 7 and the notch 8. be done. In addition, as shown in FIG. A curved portion 10 is formed in a curved shape.

[0007] FIG. 5 shows another embodiment, in which the inner surface treatment part 6 is directly attached to the inner surface of the core protection tube 4. A fine coiled fiber 14 is attached through this inner surface treatment part 6 to form a core This is a holding member 9. In this embodiment as well, the inner surface of the tip of the inner surface processing section 6 is arranged. A curved portion 10 is formed on the inner surface of the tip (or rear end) of the core protection tube 4. or, As shown in FIG. 6, the curved portion 10 may be formed into a tapered shape to form a tapered portion 10a. stomach. Note that the reference numeral 14 in FIG. 6 is a minute coiled fiber as in FIG. The difference from example 5 is that the orientation is different.

[0008] Next, a specific example of the method for formulating the inner surface of the core protection tube 4 will be described below. That's right.

[0009] The first method is to form needle-like crystals 12 on the base material 11 (see FIG. 7), More specifically, paints such as acrylic, urethane, and epoxy paints are used as base materials; Thermoplastic resins such as vinyl acetate, styrene acrylic, and vinyl chloride, acrylic Thermosetting resin powder such as resin, urethane, and epoxy, and liquid such as silicone rubber. Rubber or plating solution used for electrolytic plating or electroless plating, etc., can also be used with needles. Silicon nitride, silicon carbide, potassium titanate, zinc oxide, etc. are used as crystals. , after mixing and dispersing the needle crystals and the above-mentioned base material, if the base material is liquid, the core After immersing the protective tube 4 in the mixed dispersion liquid, air blow and permeate (soak it into paper, etc.) , remove unnecessary liquid by electrostatic dripping etc., form a film layer on the inner surface, and then heat The base material can be solidified and attached to the inner surface of the core protection tube by appropriate means such as If the powder is a solid, the needle-like crystals and the powder are simply mixed and dispersed, and then the solution is added. Either add a powder and perform the same treatment as described above, or charge these powders ( (charged when sprayed with a spray etc.), on the other hand, core protection tube (in the case of metal) After applying an electric charge and electrically attaching the charged powder to the inner surface of the core protection tube, , by heating, melting and adhering needle-shaped crystals, or by heating the core protection tube itself. After that, the powder is sprayed onto the inner surface of the core protection tube to make it come into contact with it and adhere to it. Also, If a plating solution is used as a base material, it can be used for electroplating or electroless plating. Once the plating process is performed, needle-shaped crystals are attached.

0010 In addition, the core protection tube to which the needle crystals are attached must be melted, immersed, electrolyzed, etc. in advance. Degreasing is desirable because it can improve fixing performance. In addition, along with needle-like crystals, For example, styrene, nylon, polyolefin, silicone, epoxy, polymethane Resin powders such as methyl acrylate and inorganic powders such as silica, alumina, and zirconia acrylic, urethane, and epoxy powders. Powder coated with paint (composite material), and even smaller inorganic powder added to resin powder. Automatic mortar, ball mill, jet mill, atomizer, hybridizer (Nara machine) (manufactured by Kikai Seisakusho), etc., to adsorb or inject inorganic powder into resin powder. It is preferable to use such a material because the needle-shaped crystals can be appropriately dispersed and protrude from the inner surface. Ma In addition, the above-mentioned powder does not have to be particular about its shape; for example, it can be spherical, plate-like, etc. Appropriate shapes can be used.

[0011] The second method is to use silicone, styrene, nylon, or polyolefin through the base material 11. Resin powder such as fin, epoxy, polymethyl methacrylate, silica, alumina (See Figure 8). Physically, the base materials include acrylic, urethane, and epoxy paints, and vinegar. Liquid resins such as vinyl acid, styrene acrylic, and vinyl chloride, silicone rubber liquid rubber, polyvinyl butyral resin, polyvinyl formal resin, etc. Resin powder or plating solution used for electrolytic plating or electroless plating, etc. As for the fine powder, we will discuss the use of silicone resin fine powder, which is a particularly preferable example. When this happens, a network structure in which siloxane bonds extend three-dimensionally, especially an alkali at the end of the molecular structure, is created. Those having a kill group, such as Tospar 120 with a methyl group bonded, Tospar Under the names of Le 130, Tospar 145, and Tospar 240 (Toshiba Silicon Corporation) Use what is on sale. This fine silicon powder may be used as is. For example, those with small particle size can be used with silicone, styrene, and nylon with large particle size. , on the surface of resin powder such as polyolefin, epoxy, polymethyl methacrylate, etc. On the other hand, those that have been adsorbed or implanted, or those with a large particle size, may have a small particle size. It may also be adsorbed or implanted onto a small silicon surface. material of more than First, the silicon fine powder and the base material are mixed and dispersed, and then the base material is in a liquid state. If so, after immersing the core protection tube 4 in the mixed dispersion, perform air blowing, permeation (soaking on paper, etc.). After removing unnecessary liquid by electrostatic dripping etc. and forming a film layer on the inner surface. Then, by heating or other appropriate means, the base material is solidified and applied to the inner surface of the core holding member of the core protection tube 4. If the base material is a powder, simply combine the silicone resin fine powder and the powder. Mix and disperse silicone resin powder, or adsorb or strike silicone resin fine powder onto the base material powder. or conversely, powder is adsorbed or implanted into fine silicone resin powder. Further, add a solvent and treat in the same manner as above, or use these powders. (charged when sprayed with a spray etc.), while the core protection tube After applying an electric charge and electrically attaching the charged powder to the inner surface of the core protection tube, , heat, melt and adhere fine silicone resin powder, or remove the core protection tube itself. is heated, and then the powder is sprayed onto the inner surface of the core protection tube and brought into contact with it, causing it to adhere. Ru. In addition, if a plating solution is used as a base material, it can be used for electroplating or electroless plating. If a plating process such as plating is performed, fine silicone resin powder will be attached.

0012 Note that the core holding member to which the powder 13 is attached must be melted, immersed, electrolyzed, etc. in advance. It is desirable to degrease the film in advance because it can improve fixing performance. Also, silicone is available as a fine powder. Even when using a material other than resin, the base material 11 The fine powder can be attached via.

[0013] The third method uses minute coiled fibers 14 (for example, fibers) instead of the first needle-like crystals. The diameter of the fiber is 0.1 μm to 0.3 μm, the diameter of the coil is around 5 μm, and the length is about 0.1 mm. (coiled carbon fiber) etc., and attach it via the base material 6 according to the first method. (See Figures 5 and 6). The fourth method is to use the inner surface of the core protection tube in the longitudinal direction. Three or more protrusions are formed on the inner surface, and the inner surface is coated with electroplating or electroless plating. Dry plating such as wet plating, vapor deposition, sputtering, and ion plating It is to form a film (film thickness is about 1 μm to 10 μm) by plating. Furthermore, the following In the explanation of the first to fourth methods above, the inner surface treatment part 6 is directly applied to the inner surface of the core protection tube 4. (Base material 11) is formed to form the core holding member 9. In the case of example 3, the core holding member 9 may be used instead of the core protection tube 4.

[0014]

[Effect of the idea]

This invention is based on the inner surface of the tip or the inner surface of the rear end of the core holding member provided at the tip of the shaft cylinder. A curved portion or a tapered portion is formed on at least one side of the Not only does it prevent damage, but even if the lead lead bends due to pen pressure, it can prevent the lead lead from breaking as much as possible. Ru.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG. 1.

FIG. 3 is a sectional view showing another embodiment in FIG. 2;

FIG. 4 is a longitudinal sectional view of the core protection tube in FIG. 1.

FIG. 5 is a longitudinal sectional view showing another embodiment in FIG. 4;

6 is a longitudinal sectional view showing still another embodiment in FIG. 4. FIG.

7 is a sectional view showing still another embodiment in FIG. 2. FIG.

8 is a sectional view of a main part showing still another embodiment in FIG. 2. FIG.

[Explanation of symbols]

1 Shaft tube 4 core protection tube 5 Core detent member 6 Internal processing section 7 Gap 9 Core holding member 10 Music section 10a Taper part

Claims (1)

[Scope of utility model registration request] [Claim 1] A curved portion or a tapered portion is formed on at least one of the inner surface of the tip or the inner surface of the rear end of the core holding member disposed in the core protection tube provided at the tip of the barrel. Mechanical pencil.