JP4642271B2

JP4642271B2 - mechanical pencil

Info

Publication number: JP4642271B2
Application number: JP2001157348A
Authority: JP
Inventors: 守雄秋山
Original assignee: Zebra Co Ltd
Current assignee: Zebra Co Ltd
Priority date: 2001-05-25
Filing date: 2001-05-25
Publication date: 2011-03-02
Anticipated expiration: 2021-05-25
Also published as: JP2002347383A

Description

【０００１】
【発明の属する技術分野】
本発明は、繰出機構によって繰出される芯を弾性芯挿通部材へ挿通させるようにしたシャープペンシルに関するものである。
【０００２】
【従来の技術】
従来、この種のシャープペンシルは、繰出し機構によって繰出される芯を自重により落下させないように、弾性的に芯を保持する弾性芯保持部材を、先口内あるいは先口前端の芯挿通管内に具備している。
【０００３】
しかしながら、上記従来技術によれば、弾性芯保持部材における芯の保持力が強すぎる場合、芯繰出し機構による芯の繰出し動作がスムーズに行われなかったり、芯と弾性芯保持部材との摩擦によって削れ芯を発生し、その削れ芯が先口内に詰まって芯の繰出し動作に支障をきたしたりする等の問題が懸念された。
そこで、通常、弾性芯保持部の芯の保持力は、繰出し機構による芯の繰出し動作に支障をきたすことのないように低めに設定されている。しかし、繰出し動作で繰出され繰出し機構に挟持されなくなった芯、すなわち残芯により筆記が行われた場合には、残芯が軸回りに回転したり後退したりし易く、筆記感触が損なわれてしまうという問題を有していた。
【０００４】
【発明が解決しようとする課題】
本発明は上記従来事情に鑑みてなされたものであり、その目的とする処は、芯の繰出方向の保持力を芯の後退方向の保持力よりも小さくすることで、芯の繰出し動作をスムーズにし、削れ芯の発生を少なくできる上、筆記時に残芯が回転したり後退したりし難く筆記感触の良いシャープペンシルを提供することにある。
【０００５】
【課題を解決するための手段】
上記課題を解決するための本発明の技術的手段は、繰出し機構によって繰出される芯を弾性芯保持部材内に挿通させるようにしたシャープペンシルにおいて、前記弾性芯保持部材は、その内周面の前端側と後端側に、芯の繰出方向の保持力が芯の後退方向の保持力よりも小さくなるように断面鋸刃状に形成した芯保持面を有し、前記前端側の芯保持面における鋸刃状山形面の数を、前記後端側の芯保持面における鋸刃状山形面の数よりも多く設定していることを特徴とする。
【発明の実施の形態】
【０００６】
本発明に係る実施形態は、繰出し機構によって繰出される芯を弾性芯保持部材内に挿通させるようにしたシャープペンシルにおいて、前記弾性芯保持部材は、その芯保持面を、芯の繰出方向の保持力が芯の後退方向の保持力よりも小さくなるように形成している。
ここで、上記繰出機構とは、ノック操作によって芯を繰出すようにしたノック式繰出機構や、回転操作によって芯を繰出すようにした回転式繰出機構等を含む。
そして、芯の繰出方向の保持力を芯の後退方向の保持力よりも小さくする具体例としては、上記芯保持面が断面鋸刃状に形成される。
【０００７】
更に、芯の保持をより確実にするためには、上記芯保持面が、弾性芯保持部材の内周面における軸方向へ複数配置される。
【０００８】
更に、上記芯の後退方向の保持力は、好ましくは３０ｇ〜１００ｇの範囲内に設定される。この場合、芯の繰出し方向の保持力は、１０ｇ〜３０ｇの範囲内であることが好ましい。
また、生産性向上の観点から好ましくは、上記弾性芯保持部材は、先口前端から突出すべく設けられた芯挿通管内にインサート成形される。
また、弾性芯保持部材のみによって残芯が保持されるようにするためには、上記弾性芯保持部材が先口内に固定された構成とする。
【０００９】
以下、本発明の実施の形態を図面に基づいて説明する。
図１は、本発明に係わるシャープペンシルの一例を示す。
このシャープペンシルＡは、繰出し機構２０によって繰出される芯を、先口３０の前端から突出する芯挿通管１１内に挿通させるように構成され、芯挿通管１１内には、挿通される芯を弾性的に保持する弾性芯保持部材１２を具備している。
【００１０】
繰出し機構２０は、芯タンク２２の前端に設けられたチャック２１、該チャック２１の外周で軸方向へスライドするチャックリング２３、チャック２１および芯タンク２２を後方へ付勢するスプリング（図示せず）等を具備し、軸筒４０後端側のノック操作によりチャック２１を進退させて、芯を前方へ繰出すように構成している。
【００１１】
芯挿通管１１は、黄銅等の金属材料からなり、その後端縁には、弾性芯保持部材１２を抜け防止する突縁部１１ａが一体に形成されている。
【００１２】
弾性芯保持部材１２は、合成ゴム材料や、熱可塑性エラストマー樹脂、その他の弾力性を有する合成樹脂材料等からなり、インサート成形によって芯挿通管１１と一体に構成され、芯挿通管１１を、その内周面の全面から後端側外周面にわたって覆っている。そして、この弾性芯保持部材１２には、芯挿通管１１の内側に、挿通される芯を弾性的に保持する芯保持面１２ａ，１２ａ’が複数形成されている。
【００１３】
尚、前記弾性芯保持部材１２は、芯挿通管１１と別体に構成し、後工程で芯挿通管１１に組み付けるようにしても構わないが、芯挿通管１１との密着性を向上するためには、上記態様のようにインサート成形により構成されるのが好ましい。
【００１４】
芯保持面１２ａ，１２ａ’は、芯の繰出方向の保持力を芯の後退方向の保持力よりも小さくするように形成され、例えば、弾性芯保持部材１２の内周面に複数の鋸刃状山形面１４を形成するとともに各鋸刃状山形面１４の頂部を前方へ向けることで、縦断面鋸刃状に形成されている。そして、芯保持面１２ａが弾性芯保持部材１２の前端側に形成され、芯保持面１２ａ’は同弾性芯保持部材１２の後端側に形成されている（図２参照）。
【００１５】
尚、弾性芯保持部材１２前端側の芯保持面１２ａにおける鋸刃状山形面１４の数は、同弾性芯保持部材１２後端側の芯保持面１２ａ’における鋸刃状山形面１４の数よりも多く設定されており、そのことによって、弾性芯保持部材１２の前端側において芯が確実に保持されるようにしている。
【００１６】
また、双方の芯保持面１２ａ，１２ａの各鋸刃状山形面１４の頂部によって形成される内径寸法は、芯の外径寸法よりも小さく設定されるとともに、上記した芯の後退方向の保持力が３０ｇ〜１００ｇの範囲内で、且つ芯の繰出し方向の保持力が１０ｇ〜３０ｇの範囲内になるように設定されている。
【００１７】
更に、弾性芯保持部材１２前端側の芯保持面１２ａの前端と上記芯挿通管１１の前端との間隔Ｗは、筆記により短くなる残芯１をより筆記先端部に近い位置で保持できるように、０ｍｍ〜１ｍｍの範囲内に設定されている。
【００１８】
而して、上記構成のシャープペンシルＡによれば、芯の送出方向の保持力が比較的小さく設定されているため、芯を繰出す際に、弾性芯保持部材１２の保持力が高すぎることで芯の繰出し動作に支障をきたしたり、削れ芯を多く発生させたりすることがない。
また、芯の後退方向の保持力が芯の送出方向の保持力よりも大きいため、筆記の際には、筆圧に対抗して芯が強力に保持される。
更に、短くなった残芯が後端側の芯保持面１２ａ’によって保持されない場合でも、その残芯を、鋸刃状山形面１４の数が多い前端側の芯保持面１２ａによって確実に保持することができる。
【００１９】
尚、図示例では、弾性芯保持部材１２の前端側と後端側との二箇所に断面鋸刃状の芯保持面１２ａ，１２ａ’を設けているが、三箇所以上に分散して設けたり、弾性芯保持部材１２の前端側から後端側にわたる全長にわたって設けるようにしても構わない。
【００２０】
また、図示例において、芯挿通管１１は、弾性芯保持部材１２後端側の外周面を先口３０内面に摺接させながら軸方向へスライドするように構成してあるが、弾性芯保持部材１２と一体の芯挿通管１１が先口３０内に固定された構成、すなわち、先口３０内に固定されている弾性芯保持部材１２のみによって残芯１が保持されるように、弾性芯保持部材１２を先口３０内に固定した構成であっても構わない。
【００２１】
本発明に係る実施形態は、以上説明したように構成されているので、以下に記載されるような効果を奏する。
芯の繰出方向の保持力を芯の後退方向の保持力よりも小さくしているため、芯を繰出す際に、芯の繰出し動作がスムーズな上、削れ芯の発生も少ない。しかも、筆記の際には、筆圧に対抗して芯が弾性芯保持部材の芯保持面で強力に保持されるため、残芯が軸回りに回転したり後退したりすることで筆記感触を損ねてしまうのを防止することができる。
更に、芯保持面を断面鋸刃状に形成した態様によれば、簡素な構造により芯の繰出方向の保持力を芯の後退方向の保持力よりも小さくすることができる。
その上、芯保持面を軸方向へ複数設けた態様によれば、複数の芯保持面により、芯の保持を一層確実にすることができる。
更に、芯の後退方向の保持力を、３０ｇ〜１００ｇに設定すれば、筆圧に対抗する芯の保持をより確実にし、残芯の回転を一層確実に防止することができる。
更に、弾性芯保持部材をインサート成形によって芯挿通管内に形成した態様によれば、弾性芯保持部材と芯挿通管との密着性が高いため、弾性芯保持部材が芯挿通管から抜け落ちたりすることがなく、組立工程における扱いを良好にするとともに、生産性を向上することができる。
しかも、弾性芯保持部材が先口内に固定されている態様によれば、先口と一体的な弾性芯保持部材のみによって残芯が保持されるため、例えば、繰出し機構の動作によって残芯と後続芯との間に隙間を生じた場合や、残芯が繰り出された最後の芯であり後続芯によって押されていない場合にも、その残芯が芯保持面で強力に保持されて筆圧に対抗するため、残芯が軸回りに回転したり後退したりすることで筆記感触を損ねてしまうのを防止することができる。
【図面の簡単な説明】
【図１】本発明に係わるシャープペンシルの一例を示す要部縦断面図。
【図２】芯挿通部材の一例を示す縦断面図。
【符号の説明】
１：残芯
１１：芯挿通管
１２：弾性芯保持部材
１２ａ，１２ａ’：芯保持面
２０：繰出し機構
Ａ：シャープペンシル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical pencil in which a lead fed out by a feeding mechanism is inserted through an elastic core insertion member.
[0002]
[Prior art]
Conventionally, this type of mechanical pencil is provided with an elastic core holding member that elastically holds the core in the leading end or the leading end of the leading end so that the core fed by the feeding mechanism does not fall by its own weight. ing.
[0003]
However, according to the above-described prior art, when the holding force of the lead in the elastic lead holding member is too strong, the lead feeding operation by the lead feeding mechanism is not smoothly performed, or the lead is scraped by friction between the lead and the elastic lead holding member. generating a core, the scraping core is like or Kitaichi the disabled supported jammed before the mouth to the feeding behavior of the core of the problem has been a concern.
Therefore, usually, the holding force of the core of the elastic core holding portion is set low so as not to adversely impaired supporting the feeding operation of the core by the feeding mechanism. However, when writing is performed with a lead that has been drawn out by the feeding operation and is no longer held by the feeding mechanism, that is, when the remaining core is written, the remaining core is easily rotated around the axis or moved backward, and the writing feel is impaired. It had the problem of end.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described conventional circumstances, and an object thereof is to make the lead feeding operation smooth by making the holding force in the lead feeding direction smaller than the holding force in the lead backward direction. Another object of the present invention is to provide a mechanical pencil that can reduce the occurrence of shaving cores and has good writing feel because the remaining core is difficult to rotate or retreat during writing.
[0005]
[Means for Solving the Problems]
The technical means of the present invention for solving the above problems is a mechanical pencil in which the lead fed out by the feeding mechanism is inserted into the elastic lead holding member, and the elastic lead holding member is formed on the inner peripheral surface thereof. The front end side and the rear end side have a core holding surface formed in a sawtooth cross-section so that the holding force in the feeding direction of the lead is smaller than the holding force in the backward direction of the lead, and the lead holding surface on the front end side The number of saw-toothed chevron surfaces is set to be larger than the number of saw-tooth chevron surfaces on the core holding surface on the rear end side .
DETAILED DESCRIPTION OF THE INVENTION
[0006]
In an embodiment according to the present invention, in the mechanical pencil in which the lead fed out by the feeding mechanism is inserted into the elastic lead holding member, the elastic lead holding member holds the lead holding surface in the lead feeding direction. The force is formed to be smaller than the holding force in the retreat direction of the core.
Here, the feeding mechanism includes a knock-type feeding mechanism that feeds the lead by a knocking operation, a rotary feeding mechanism that feeds the lead by a rotating operation, and the like.
As a specific example in which the holding force in the feeding direction of the lead is made smaller than the holding force in the backward direction of the lead, the lead holding surface is formed in a cross-sectional saw blade shape.
[0007]
Furthermore, in order to make the holding of the core more reliable, a plurality of the core holding surfaces are arranged in the axial direction on the inner peripheral surface of the elastic core holding member.
[0008]
Furthermore, the holding force in the retreat direction of the core is preferably set within a range of 30 g to 100 g. In this case, the holding force in the feeding direction of the lead is preferably in the range of 10 g to 30 g.
Further, from the viewpoint of improving productivity, the elastic core holding member is preferably insert-molded in a core insertion tube provided to protrude from the front end of the front end.
Further, in order to hold the remaining core only by the elastic core holding member, the elastic core holding member is fixed in the tip.
[0009]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a mechanical pencil according to the present invention.
The mechanical pencil A is configured so that the lead fed out by the feeding mechanism 20 is inserted into the core insertion tube 11 protruding from the front end of the tip 30, and the core to be inserted is inserted into the core insertion tube 11. An elastic core holding member 12 that elastically holds is provided.
[0010]
The feeding mechanism 20 includes a chuck 21 provided at the front end of the lead tank 22, a chuck ring 23 that slides in the axial direction on the outer periphery of the chuck 21, and a spring (not shown) that biases the chuck 21 and the lead tank 22 backward. Etc., and the chuck 21 is advanced and retracted by a knocking operation on the rear end side of the shaft tube 40 so that the lead is fed forward.
[0011]
The core insertion tube 11 is made of a metal material such as brass, and a projecting edge portion 11a for preventing the elastic core holding member 12 from coming off is integrally formed at the rear end edge thereof.
[0012]
The elastic core holding member 12 is made of a synthetic rubber material, a thermoplastic elastomer resin, other elastic synthetic resin material, or the like, and is integrally formed with the core insertion tube 11 by insert molding. It covers from the entire inner peripheral surface to the rear end side outer peripheral surface. The elastic core holding member 12 has a plurality of core holding surfaces 12 a and 12 a ′ that elastically hold the core to be inserted inside the core insertion tube 11.
[0013]
The elastic core holding member 12 may be configured separately from the core insertion tube 11 and assembled to the core insertion tube 11 in a later process, but in order to improve adhesion to the core insertion tube 11. For this, it is preferable to be constructed by insert molding as in the above embodiment.
[0014]
The core holding surfaces 12a and 12a ′ are formed so that the holding force in the feeding direction of the core is smaller than the holding force in the retracting direction of the core. For example, a plurality of saw blade shapes are formed on the inner peripheral surface of the elastic core holding member 12. By forming the chevron surface 14 and orienting the top of each saw-tooth chevron surface 14 forward, it is formed in a longitudinal section saw-tooth shape. The core holding surface 12a is formed on the front end side of the elastic core holding member 12, and the core holding surface 12a 'is formed on the rear end side of the elastic core holding member 12 (see FIG. 2).
[0015]
The number of saw-toothed chevron surfaces 14 on the core holding surface 12a on the front end side of the elastic core holding member 12 is greater than the number of saw-toothed chevron surfaces 14 on the core holding surface 12a 'on the rear end side of the elastic core holding member 12. In this way, the core is securely held on the front end side of the elastic core holding member 12.
[0016]
Further, the inner diameter dimension formed by the tops of the saw-toothed chevron surfaces 14 of both core holding surfaces 12a and 12a is set smaller than the outer diameter dimension of the core, and the above-described holding force in the backward direction of the core. In the range of 30 g to 100 g, and the holding force in the feeding direction of the core is set in the range of 10 g to 30 g.
[0017]
Further, the interval W between the front end of the core holding surface 12a on the front end side of the elastic core holding member 12 and the front end of the core insertion tube 11 is such that the remaining core 1 that is shortened by writing can be held at a position closer to the writing tip. , 0 mm to 1 mm.
[0018]
Thus, according to the mechanical pencil A configured as described above, since the holding force in the lead feeding direction is set to be relatively small, the holding force of the elastic lead holding member 12 is too high when the lead is fed out. in or Kitaichi the impaired supporting the feeding operation of the core, never or generating a lot of scraping core.
Further, since the holding force in the retracting direction of the lead is larger than the holding force in the sending direction of the lead, the lead is strongly held against writing pressure when writing.
Furthermore, even if the residual core of shortened is not held by the core holding surface 12a 'of the rear end side, the residual core, ensure the core holding surface 12a number of multi have front-end side of the sawtooth chevron surface 14 Can be held.
[0019]
In the illustrated example, the core holding surfaces 12a and 12a ′ having a sawtooth cross section are provided at two locations on the front end side and the rear end side of the elastic core holding member 12. However, the elastic core holding member 12 may be provided in three or more locations. The elastic core holding member 12 may be provided over the entire length from the front end side to the rear end side.
[0020]
Further, in the illustrated example, the core insertion tube 11 is configured to slide in the axial direction while sliding the outer peripheral surface on the rear end side of the elastic core holding member 12 to the inner surface of the tip 30. 12 in which the core insertion tube 11 integral with the front end 30 is fixed, that is, the elastic core is held so that the remaining core 1 is held only by the elastic core holding member 12 fixed in the front end 30. The member 12 may be configured to be fixed in the tip 30.
[0021]
Since the embodiment according to the present invention is configured as described above, the following effects can be obtained.
Since the holding force in the lead feeding direction is made smaller than the holding force in the lead retreating direction, when the lead is drawn out, the lead feeding operation is smooth and the generation of the scraped lead is small. In addition, when writing, the core is strongly held by the core holding surface of the elastic core holding member against the writing pressure, so that the remaining core rotates around the axis and moves backward to provide a writing feel. It is possible to prevent damage.
Furthermore, according to the aspect in which the core holding surface is formed in a sawtooth shape in cross section, the holding force in the feeding direction of the core can be made smaller than the holding force in the backward direction of the core by a simple structure.
In addition, according to the aspect in which a plurality of core holding surfaces are provided in the axial direction, the core can be held more reliably by the plurality of core holding surfaces.
Furthermore, if the holding force in the retreat direction of the lead is set to 30 g to 100 g, it is possible to more reliably hold the lead against the writing pressure and prevent the remaining lead from rotating more reliably.
Furthermore, according to the aspect in which the elastic core holding member is formed in the core insertion tube by insert molding, the adhesiveness between the elastic core holding member and the core insertion tube is high, so that the elastic core holding member may fall out of the core insertion tube. Therefore, it is possible to improve the handling in the assembly process and improve the productivity.
In addition, according to the aspect in which the elastic core holding member is fixed in the front opening, the remaining core is held only by the elastic core holding member integral with the front opening. Even if there is a gap between the lead and the last lead that has been fed out and is not pushed by the trailing lead, the remaining lead is strongly held by the lead holding surface, and pressure is applied. In order to counteract, it is possible to prevent the writing feeling from being impaired by the remaining core rotating or retreating around the axis.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part showing an example of a mechanical pencil according to the present invention.
FIG. 2 is a longitudinal sectional view showing an example of a core insertion member.
[Explanation of symbols]
1: Remaining core 11: Core insertion tube 12: Elastic core holding member 12a, 12a ': Core holding surface 20: Feeding mechanism A: Mechanical pencil

Claims

In the mechanical pencil in which the lead fed out by the feeding mechanism is inserted into the elastic lead holding member,
The elastic core holding member has a core holding formed in a saw blade shape in cross section so that the holding force in the feeding direction of the core is smaller than the holding force in the retracting direction of the core on the front end side and the rear end side of the inner peripheral surface thereof And the number of serrated chevron surfaces on the front end side core holding surface is set larger than the number of serrated chevron surfaces on the rear end side core holding surface. mechanical pencil.

The elastic core holding member is provided in a core insertion tube protruding from the front end of the tip,
The mechanical pencil according to claim 1 , wherein a distance between a front end of the front core holding surface of the elastic core holding member and a front end of the core insertion tube is set in a range of 0 mm to 1 mm. .

The mechanical pencil according to claim 1 or 2 , wherein the elastic core holding member is insert-molded in the core insertion tube .

The mechanical pencil according to any one of claims 1 to 3, wherein the holding force in the retreat direction of the core is set in a range of 30 g to 100 g.

The mechanical pencil according to any one of claims 1 to 4, wherein the elastic core holding member is fixed in the tip .