JP3605972B2 - Writing implement - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, the ink penetrating member is elastically deformed by receiving a sliding force by a pressing member slidable in a longitudinal direction between an ink tank containing ink in a free state and a pen tip member. The present invention relates to a raw ink type writing implement using a so-called elastic valve, in which a valve member that opens and closes is interposed.
[0002]
[Prior art]
As a writing implement with a valve mechanism between the ink tank and the pen tip, it is made of an elastic material such as silicone rubber. Is known, which has a valve member that closes the ink through hole by elastically recovering the shape when is released.
[0003]
Since such a writing instrument needs to use an elastic material as a valve member, the valve member must be a member different from other members such as a shaft cylinder. However, it is inevitable that the valve member comes into contact with ink due to its function, and ink leakage will occur unless liquid tightness with other members such as the writing instrument body around the valve member is ensured. Although it is possible to adhere the valve member to another member in contact with an adhesive, or to weld the member using ultrasonic waves, heat, a solvent, or the like, it is not practical because the manufacturing operation becomes complicated and the cost increases. Therefore, since the adhesion of the ink through hole when the valve is closed can also be strengthened, the diameter of the valve member is made slightly larger than the diameter of the mounting portion of the shaft cylinder, and the valve member is pressed in by applying a radial clamping force to the valve member. What is fixed in a shape is known.
[0004]
[Problems to be solved by the invention]
In the case where the valve member is fixed by the clamping force in the radial direction as shown in the above-mentioned prior art, a certain degree of liquid tightness with other members that come into contact with the valve member can be obtained, but the ink through hole can be smoothly formed. There was a possibility that a problem might occur in the opening and closing of the door. That is, the fact that a radial force is applied to the valve member means that the abutment between the inner wall surfaces in the ink through hole is also strong, that is, the closing force of the ink through hole is strong. Although the liquid-tightness may seem to be enhanced at first glance, it is an obstacle when opening the ink passage. A valve member made of an elastic material can originally achieve both high liquid-tight reliability and the ability to open a valve with a light force. However, when an excessive closing force is applied to the ink through hole beyond the elastic force of the elastic material, there is a problem in that the opening of the ink through hole is poorly opened. In addition, when the excessive closing force is increased, deformation occurs in the ink through-hole portion, so that the ink through-hole is opened even at the time of closing, and the liquid-tight reliability may be reduced. In particular, in the case of mass-produced products, there is a possibility that dimensional variations of the members may occur, so that a change in the holding force with respect to the valve member cannot be absorbed, and there is a danger that the above-described problem will occur significantly.
[0005]
[Means for Solving the Problems]
That is, according to the present invention, between the ink tank storing the ink in a free state and the pen point member, the ink receiving hole is elastically deformed by receiving a sliding force by a pressing member slidable in the longitudinal direction, and the ink through hole is opened. In a writing instrument having a valve member to be closed, the valve member has a pressure buffer space on the ink tank side which is a concave portion for reducing a pressing force when opening an ink through hole, and has a longitudinal direction. The gist of the present invention is a writing instrument fixed in a shaft cylinder by a holding force.
[0006]
[Action]
In the writing instrument of the present invention, since the valve member made of an elastic material is fixed by the clamping force in the longitudinal direction, it is possible to obtain sufficient liquid tightness with other members in contact with the valve member, and of course, to impart a strong clamping force. However, it does not easily affect the periphery of the ink hole, and does not reduce the liquid-tight reliability and the ease of opening the ink hole. Further, even if the dimensional variation of the members occurs, the holding force of the valve member can be adjusted by adjusting the position of the shaft cylinder in the longitudinal direction and adjusting the holding force, so that the quality of the ink through hole is hardly affected. In addition, a predetermined portion of the valve member is displaced in the radial direction by the longitudinal clamping force applied to the valve member, and is brought into contact with the writing implement main body. Properties can be further improved. Further, the radial force applied to the contact portion between the valve member and the writing instrument main body is dispersed by the pressure buffer space so as not to directly affect the ink passage.
[0007]
【Example】
Hereinafter, an example will be described with reference to the drawings.
In the writing implement A of FIG. 1, a polypropylene pipe material having low moisture permeability is installed as an ink tank 2 in the inner hole of the rear shaft 1. A pen point holder 3 is fixed to the front end of the rear shaft 1 by fitting in a concave and convex manner. The rear shaft 1 and the pen point holder 3 constitute a shaft cylinder. Inside the ink tank 2, a backflow preventive composition 8 and a buoy 9 composed of a high-viscosity fluid such as polybutene or α-olefin oil are arranged at the interface position of the ink to suppress the leakage of the ink from the rear end of the pipe body. I have. The backflow preventing body composition 8 and the buoyant stopper 9 move together with the ink interface due to the amount of ink loss accompanying ink consumption.
[0008]
A pen tip 5 is slidably mounted in the inner hole 4 of the pen tip holder 3. As shown in FIG. 2, which is an enlarged cross-sectional view of a portion I in FIG. 1, the pen tip 5 has a stepped portion at the rear end portion and has a reduced diameter portion 5a. Reference numeral 6 denotes a valve member made of an elastic material such as silicone rubber, ethylene propylene rubber, styrene butadiene rubber, butadiene rubber, nitrile rubber, urethane rubber, butyl rubber, and the like. It comprises a portion 6a and a flat deformed surface portion 6b having a cut-shaped ink passage hole 6c. The deformed surface portion 6b is a portion to which a pressing force such as a pen pressure is transmitted by a pen tip, and is elastically deformed by the pressing force to open the ink through hole 6c. Here, by setting the contact relationship between the pen tip 5 and the valve member 6 and the length of the ink penetrating hole 6c, the ink penetrating hole 6c is opened simultaneously with the movement of the pen tip 5, Whether or not the ink through hole 6c is opened only after the movement reaches a certain point can be appropriately set.
[0009]
The end surface 5b of the reduced diameter portion 5a of the pen tip 5 is a pressing portion against the valve member 6, and presses the deformed surface portion 6b of the valve member 6 as the pen tip 5 slides, thereby opening the ink through hole 6c. Open. In other words, the pen tip 5 slides toward the ink tank 2 when a slight pressing force such as a pen pressure is applied, and when the pressing force is released, the pen tip 5 is urged forward by the elastic force of the valve member 6 and thus moves forward. I do.
[0010]
Further, a locking step 3a for arranging a valve member is formed in the inner hole 4 of the pen tip holder 3, and the tip of the ink tank 2 is pressed into the inner hole 4 of the pen tip holder 3 while being in contact with the valve member 6. The fixing force of the ink tank 2 ensures liquid tightness between the valve member 6 and the ink tank 2 serving as a writing instrument body. Further, a forward regulating step 7 is formed behind the inner hole 4 of the pen tip holder 3, and serves as a movement regulating section for the valve member 6 and the ink tank 2 when the pen tip 4 is excessively pressed.
[0011]
As described above, the valve member 6 is sandwiched and fixed between the ink tank 2 and the pen tip holder 3. That is, in the present embodiment, the leading end 2 a of the ink tank 2 and the circumferential locking step 3 a formed in the inner hole 4 of the pen tip holder 3 are locking portions for holding the valve member 6. The tip 2a of the ink tank 2 and the locking step 3a of the pen tip holder 3 are portions to which the pinching force is directly applied. Considering the influence of the diffusion of the force on the ink through hole 6c, the writing implement body and the valve It is preferable that the portion where the member 6 comes into contact with and the force is applied is located as far away from the ink through hole 6c as possible. Further, the concave portion 6e is a portion serving as a fulcrum when the ink through hole 6c is opened, and the valve member 6 reduces the amount of compressive deformation and can be opened with a light force. Therefore, it is preferable that the position where the valve member 6 receives the holding force be located outside the concave portion 6e so as not to hinder the opening of the ink through hole 6c.
[0012]
Further, in the case of this example, in order to easily increase the holding force for fixing the valve member 6, a circumferential projection 6d is formed at a contact portion of the valve member 6 with the ink tank 2 and the pen tip holder 3. The peripheral protrusion 6d can be formed in a conical shape, a dome shape, a trapezoidal shape, or the like. In any case, when receiving the pinching force, the tip of the projection is crushed, and the contact portion is in surface contact. However, a semicircular shape is advantageous because a large contact area can be secured with a small amount of crushing. I can say. Further, in the case of a conical shape, when the same load is sandwiched, the load applied per unit area can be increased, and high liquid tightness can be achieved.
[0013]
Although other embodiments are shown in FIG. 3 and subsequent figures, basically the same portions are denoted by the same reference numerals, and are shown as those corresponding to FIG. 2 of the above-described example. The one shown in FIG. 3 is basically the same as the above-mentioned example, except that a circumferential projection 6 d is not formed on the valve member 6, and the locking step between the tip end of the ink tank 2 and the nib holder 3 is performed. The projections 2b and 3b are formed on the portion 3a. Unlike the valve member 6, the ink tank 2 and the pen tip holder 3 are injection-molded articles of relatively hard synthetic resin such as polyethylene, polypropylene, PET, AS, and ABS. Therefore, the displacement in the radial direction is less likely to occur than when the projection is formed on the valve member 6. Thereby, a gap 10 can be formed between the largest diameter portion of the valve member 6 and the inner wall of the rear shaft 1. By ensuring the gap 10, even if there is a variation in the diameter of the valve member 6, the variation can be absorbed, and a radial clamping force is applied to the valve member 6 to improve the quality of the ink through hole 6 c. Is unlikely to adversely affect
[0014]
Further, since no circumferential projection is formed on the valve member 6, the contact position between the valve member 6 and the ink tank 2 or the nib holder 3 is not specified. It can be of various thicknesses within the range.
[0015]
4 and 5 show still another example. FIG. 4 shows a state in which the ink tank 2 is installed and a pinching force is applied to the valve member 6, and FIG. 5 shows a state before the valve member 6 is deformed immediately before the pinching force is applied.
A deformation portion 6f that is displaced in the radial direction when a longitudinal holding force is applied to the valve member 6 is formed. The deformed portion 6f in the present example has a circumferential concave portion 6g formed in the outer peripheral portion of the valve member 6, so that when the pressing force of the ink tank 2 receives a longitudinal holding force, the holding force becomes a circumferential shape. Concentrated in the recess 6g, the portion serves as a fulcrum, and the deformed portion 6f is displaced radially outward. The deformed portion 6f displaced outward presses the front end portion 2a of the ink tank 2 and the inner wall of the pen tip holder 3 to further improve liquid tightness. Further, a concave pressure buffer space 11 is formed between the contact portion between the valve member 6 and the ink tank 2 or the pen tip holder 3 and the ink through hole 6c, and a certain clamping force is applied to the valve member 6. Even so, the ink through-hole 6c is made so as not to be affected by the pressure as much as possible. Further, it is preferable that the ink tank 2 is brought into contact with the outer side of the deformed portion 6f of the valve member 6 as much as possible. In this embodiment, the outer diameter of the ink tank 2 is larger than the outer diameter of the valve member 6.
[0016]
6 and 7 show still another example. 4 and 5, FIG. 6 shows a state in which the ink tank 2 is installed and a clamping force is applied to the valve member 6, and FIG. 7 shows a state before the valve member 6 is deformed immediately before the clamping force is applied. Is shown.
This is an example in which a deformed portion 6f that is displaced in a radial direction when a longitudinal holding force is applied to the valve member 6 is formed. In the present example, the annular projection is formed on the deforming portion 6f such that the contact portion between the tip end portion 2a of the ink tank 2 and the valve member 6 is located radially outside the contact portion of the valve member 6 with the pen tip holder 3. 6h. Due to the formation of the annular protrusion 6h, even if the ink tank 2 pushes the inside of the annular protrusion 6h due to a dimensional variation between the members, the annular protrusion 6h is displaced outward to enhance the adhesion. be able to.
[0017]
8 and 9 show still another example. 8 shows a state in which the ink tank 2 is installed and a pinching force is applied to the valve member 6, similarly to FIGS. 4 and 5. FIG. 9 shows a state before the valve member 6 is deformed immediately before the pinching force is applied. Is shown.
This is an example in which the shape of the deformed portion 6f of the valve member 6 is devised so that the deformed portion is easily displaced in the radial direction. That is, as shown in FIG. 9 showing the radial shape of the valve member 6 before the holding force is applied, the deformed portion 6f is formed as an annular projection having a triangular cross section with the apex positioned as far outward as possible. The holding force is easily applied to the outside, and the deformed portion is easily bent outward.
[0018]
FIG. 10 shows still another example. The valve member 6 receives a pressure toward the center in the radial direction, not less than a little, at a contact portion with the ink tank 2 and the pen tip holder 3. In particular, when a longitudinal clamping force is applied to the valve member 6 as in the present invention, the valve member 6 is deformed in a direction in which its diameter is enlarged by a longitudinal compressive force and pushes a peripheral wall. As a reaction, a pressure toward the center in the radial direction is received. A pressure toward the center in the radial direction is applied between the contact portion between the valve member 6 and the ink tank 2 or the pen tip holder 3, which is a portion for applying the pressure toward the center in the radial direction, and the ink through hole 6c. A concave pressure buffer space 11 is formed so as not to be directly applied to the hole 6c. That is, the contact portion between the valve member 6 and the ink tank 2 or the pen tip holder 3 is not linearly connected to the ink through hole 6c. 6c is made so as not to be affected by the pressure as much as possible. Further, by forming the pressure buffer space 11 as a concave portion formed on the ink tank side, the pressing force for opening the ink through hole 6c by the pen tip 4 can be reduced.
[0019]
FIG. 11 shows still another embodiment. The difference from the above-described example is that the pressure buffer space 11 is formed on both the ink tank side and the pen tip side of the valve member 6. Further, the pressure buffer space 11 is formed such that the concave bottom portion has an acute angle so that the pressure in the center direction of the elastic valve can be easily concentrated on the concave portion, and the pressure buffer space 11 reliably absorbs the pressure. Therefore, the quality of the ink holes is hardly adversely affected. Further, by forming the pressure buffer space 11 also on the pen tip side, it is possible to buffer the pressure toward the center, such as the clamping force, over the entire front and rear direction of the valve member 6. Therefore, it can be said that the shape is such that no pressure is applied to the ink through-hole.
[0020]
In addition to the above, various modifications can be made without departing from the gist of the present invention. For example, the ink tank 2 may use the inner hole of the rear shaft 1 as it is. In this case, the valve member 6 may be inserted by inserting another ring-shaped member or by using a shaft cylinder. This can be done by forming a circumferential inward protrusion on the inner wall. In addition, the ink tank 2 has a slide stopper that moves with the decrease in the amount of ink, reduces the internal space, and has a ventilation hole that communicates with the ink tank 2 so that air is taken in with the consumption of ink. Or a cartridge-type writing instrument having an exchangeable ink tank 2 attached thereto. As shown in FIG. 1, the pen tip 5 is formed by forming a fiber converging body such as an acrylic fiber or a polyester fiber into an appropriate shape, as well as a synthetic resin pen having an ink through hole formed therein. A tip, a small tube type nib having a hard cylinder and a needle as a nib, a ball-point nib, etc. may be used. Further, the ink penetrating hole 6c of the valve member 6 is opened by sliding the pen tip 5, but another member for communicating a pressing force (sliding force) between the pen tip 5 and the valve member 6 is provided. It may be interposed, or a pressing-only member may be provided to the valve member 6 without sliding the pen tip, and for example, a writing tool of a rear end knock type may be provided.
[0021]
【The invention's effect】
As described above, the writing instrument of the present invention has a simple structure with good assembling workability, and can reliably and smoothly operate with a small pressing force of the ink through hole of the valve member even when an environmental change such as a temperature rise occurs. It is possible to obtain a writing implement that is opened and closed reliably and smoothly, and is unlikely to cause ink leakage or ejection failure.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example.
FIG. 2 is an enlarged sectional view of a part I of FIG.
FIG. 3 is a diagram corresponding to FIG. 2, showing another example.
FIG. 4 is a view corresponding to FIG. 2, showing still another example.
FIG. 5 is a view corresponding to FIG. 4, showing a state before assembly.
FIG. 6 is a view corresponding to FIG. 2, showing still another example.
FIG. 7 is a diagram corresponding to FIG. 6 showing a state before assembly.
FIG. 8 is a view corresponding to FIG. 2, showing still another example.
FIG. 9 is a view corresponding to FIG. 8, showing a state before assembly.
FIG. 10 is a diagram corresponding to FIG. 2, showing still another example.
FIG. 11 is a view corresponding to FIG. 2, showing still another example.
[Explanation of symbols]
A Writing implement 1 Rear shaft 2 Ink tank 2a Tip 2b Projection 3 Nib holder 3a Lock step 3b Projection 4 Inner hole 5 Pen tip 5a Reduced diameter portion 5b End surface 6 Valve member 6a Fixed portion 6b Deformed surface portion 6c Ink through hole 6d Protrusion 6e Recess 6f Deformed portion 6g Recess 6h Annular protrusion 7 Advance regulating step 8 Backflow prevention composition 9 Float 10 Gap 11 Pressure buffer space

Claims (2)

A valve member is interposed between the ink tank that stores ink in a free state and the pen tip member, which is elastically deformed by receiving a sliding force by a pressing member slidable in the longitudinal direction to open and close the ink through hole. In the writing implement, the valve member has a pressure buffer space on the ink tank side, which is a concave portion for reducing the pressing force when opening the ink through-hole, and the inside of the shaft cylinder is formed by a clamping force in the longitudinal direction. Writing instrument fixed to. When the valve member receives the pinching force in the longitudinal direction, a deformed portion that is displaced radially outward is provided, and the deformed portion is applied to a portion different from a portion that applies the pinching force to the valve member of the writing instrument body. 2. The writing implement according to claim 1, wherein the writing implement is brought into liquid-tight contact.

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