JP3467883B2 - Writing implement - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressing member slidable in a longitudinal direction between an ink tank containing ink in a free state and a pen point member. The present invention relates to a writing implement including a valve member that opens and closes an ink passage by being elastically deformed by receiving a sliding force of the writing instrument. 2. Description of the Related Art A so-called raw ink type writing instrument which stores ink in a free state without providing an ink holding member such as a batting inside an ink tank can store a large amount of ink. On the other hand, on the other hand, there is a problem that unless the supply of the ink to the pen tip is strictly controlled, ink leakage, writing marks, etc. are likely to occur. As an example of a writing implement provided with a valve mechanism between an ink tank and a pen tip, Japanese Patent Application Laid-Open No. 6-24195 discloses a notch made of an elastic material, which receives a pressing force due to the sliding of the pen tip and receives a notch. A writing implement having a valve member that opens the ink passage in the shape of a circle and that elastically contracts when the pressing force is released to close the ink passage is shown. [0004] A raw ink type writing instrument is
It has the advantage that fresh handwriting can be obtained because abundant ink can be supplied to the pen tip member,
Due to the abundant supply of ink, there is a problem that ink leakage or excessive ink ejection tends to cause handwriting spots. In particular, when the inside of the ink tank is pressurized due to a temperature change or the like, pressure is applied in all directions of the wall of the ink tank. Direction, the ink penetrates into the ink passage of the valve without sliding the pen tip, which is the member that applies the pressing force to the valve.If the pressure is high, the ink passage is opened. As a result, there is a problem that ink is supplied to the pen tip against the user's will and ink leakage occurs. That is, the present invention provides a sliding force between a pen tip member and an ink tank containing ink in a free state by a pressing member slidable in a longitudinal direction. In a writing instrument having a valve member that opens and closes the ink passage by receiving and deforming elastically upon receiving, the ink passage wall of the valve member has a longitudinal overlapping portion. The writing instrument to be used is the gist. In the writing instrument according to the present invention, since the ink passage wall of the valve member has a longitudinal overlapping portion, the inside of the ink tank is pressurized, and the valve member is pressed from the inside of the ink tank toward the pen tip. When the pressure is applied to the ink passage, the overlapping portions of the ink passage wall portions come into pressure contact with each other, so that it is possible to further suppress the penetration of the ink into the ink passage. An embodiment will be described below with reference to the drawings.
The writing implement A in FIG. 1 uses the inner hole 2 of the barrel 1 as an ink tank as it is, and is an example of a so-called non-ink replenishment type raw ink writing implement. A pen point holder 3 is press-fitted and fixed to the tip of the barrel 1, and is prevented from falling off by a projection 4 formed on the inner wall of the barrel 1. Also,
In order to prevent ink from leaking between the inner wall of the barrel 1 and the pen tip holder 3, an all-round rib 3a having a comb-like cross section is formed on the outer periphery of the pen tip holder 3, and a part thereof. Is formed with a slit 3b as an air passage. A pen tip 5 is slidably mounted in the center hole 3c of the pen tip holder 3 in the axial longitudinal direction. The pen tip 5 comes in contact with a valve member 6 made of an elastic synthetic resin. In other words, the pen tip 5 moves toward the ink tank when a slight pressing force such as a pen pressure is applied. In this state, the pen tip 5 is urged forward by the elastic force of the valve member 6. And return to the original state. Since a stepped locking portion is formed in the center hole 3c of the pen tip holder 3, the pen tip 5
Is prevented from falling off. Further, the valve member 6 is restricted from moving backward by a step-like locking portion formed on the inner wall of the shaft cylinder. Here, the valve member 6 is composed of a fixed leg 6a for the shaft cylinder 1 and a flat deformed portion 6b in which a cut-shaped ink passage 6c is formed. When a pressing force such as writing pressure is applied to the pen tip 5, the pen tip 5 moves to the ink tank side and presses the deformed portion 6b of the valve member 6. The deformed portion 6b is elastically deformed by the pressing force and opens the ink passage 6c. Here, by setting the contact relationship between the pen tip 5 and the valve member 6, the ink passage 6c is opened simultaneously with the movement of the pen tip 5, or the ink passage is not reached until the pen tip 5 reaches a certain point. Whether or not 6c is opened can be appropriately set. Further, a groove 6e is formed in the deformed portion 6b, so that the deformation of the valve member 6 by the pen tip 5 and the ink passage 6
The opening of the ink passage 6c can be easily performed with a small force, and the force from the ink passage toward the pen tip does not easily deform the valve member 6 and open the ink passage 6c. As shown in FIG. 2, which is an enlarged cross-sectional view of the portion I of FIG. 1, the cut-shaped ink passage 6c formed in the deformed portion 6b of the valve member 6 is cut in the axial direction by a blade such as a cutter. Is formed by cutting obliquely with respect to. As shown in FIG. 3 which is a view taken in the direction of arrow II in FIG. 2, the ink passage 6c has an opening 7 on the ink tank side, an opening 8 on the pen tip 5 side, and an ink passage portion connecting both of them. It is formed as a hole at a substantially central portion of the deformed portion 6b in consideration of ease of forming an ink passage and ease of installation in a writing instrument. The ink passage 6c may extend substantially over the entire width of the deformed portion 6b, and the valve member 6 may be substantially composed of two members (not shown). In this embodiment, the valve member 6 is
The overlapping portion 6d in the longitudinal direction extends over the entirety c.
Therefore, when a longitudinal pressing force is applied due to, for example, a pressurized state in the ink tank, the overlapping portion 6d becomes an obstacle, and the ink seeps into the ink passage 6c or the ink passage 6c is opened. Can be suppressed as much as possible. Further, since the ink passage 6c in this embodiment is a straight cut-shaped hole (slit), the pressing force acting on the valve member 6 is released after the valve member 6 is deformed to open the ink passage 6c. When the operation is performed, the ink passage 6c is immediately closed to be in a liquid-tight state. Here, as the material of the valve member 6 of the present embodiment,
Although styrene-butadiene rubber is used, any synthetic resin having elasticity can be used without any particular limitation. Silicon rubber, butyl rubber, polyethylene, polypropylene, styrene-butadiene rubber, nitrile-butadiene rubber, ethylene-propylene rubber, etc. Can be mentioned. In particular, in the case of styrene-butadiene rubber, the rebound resilience is high, and even if the pressing force is released, the ink path does not return to the original state and the ink path is kept open, or the ink path 6c does not contact in a liquid-tight manner. Exudation is prevented, air permeability is high, and air enters the ink tank even if the ink passage 6c is closed for a long time even if the ink passage 6c is closed for a long time. In addition, the ink has high wettability with ink, so that the continuity of the ink is good, space is hardly generated, there is no problem such as running out of ink, and the cost is relatively low. Nitrile butadiene rubber has high rebound resilience, ensures opening and closing of the ink passage 6c almost as well as styrene butadiene rubber, and is relatively low cost. Ethylene propylene rubber has ozone resistance and ultraviolet light resistance. It is excellent in weather resistance such as heat, moisture, active gas, day and night temperature cycle, so even if it is left outdoors, the occurrence of so-called deterioration cracks due to participation of double bonds of rubber can be suppressed and it can be damaged. Absent. Incidentally, if necessary, a plurality of kinds of materials can be molded by mixing, for example, nitrile butadiene rubber and ethylene propylene rubber. FIG. 4 shows another example. The basic configuration is the same as the above-described example, except that the valve member 6 has two members,
The ink passage 6c is a contact portion between the two members.
The ink passage 6c of this example is formed in a step-like manner, and the longitudinally overlapping portion 6d of the valve member 6 is formed as a plane perpendicular to the axial longitudinal direction. Compared with the above-described example, the path of the ink passage 6c becomes longer, and the time required for ink communication with the pen tip 5 when the ink passage is opened is considered to be somewhat longer. Since the vertical surface is the overlapping portion, the ink passage 6c can be kept closed even when a higher pressure is applied than in the ink tank. In order to provide a valve member having such a stepped ink passage, two or more valve members in which the notched ink passage is formed at a position shifted from the radial center of the deformed portion in addition to the illustrated example are stacked. In addition, the contact portion between the members may be an overlapping portion 6d so that the ink passage 6c as a whole has a stepped shape. FIG. 5 shows still another example. The point that the ink passage 6c is formed as a cut-shaped hole obliquely to the longitudinal direction of the shaft is the same as the example of FIG. 2, but the ink passage is substantially the same as that of the cut-shaped hole parallel to the longitudinal direction of the shaft. Is an example in which the length of the overlapping portion is realized. In other words, the notch 6f of the flesh portion is formed on the pen tip 5 side of the ink passage 6c, and the overlapping portion 6d is shortened. Various modifications can be made without departing from the gist of the present invention. To give an example, the ink tank has a slide stopper that moves as the amount of ink decreases, the internal space decreases, and a vent that communicates with the ink tank, and takes in air as the ink is consumed. Such a cartridge may be used, or a cartridge-type writing instrument provided with an exchangeable ink tank may be used. As shown in FIG. 1, the pen tip 5 may be formed by forming a fiber converging body of acrylic fiber or polyester fiber into an appropriate shape, or a synthetic resin pen tip having an ink passage formed therein. Alternatively, a small tubular nib having a hard cylindrical body and a needle as a nib, or a ball nib with a hard ball rotatably held in a tip may be used. Furthermore, although the ink passage 6c of the valve member 6 is opened by sliding the pen tip 5, another member for communicating the pressing force (sliding force) is interposed between the pen tip 5 and the valve member 6. Alternatively, a member dedicated to pressing the valve member 6 may be provided without sliding the pen tip, and for example, a writing tool of a rear end knock type may be provided. As described above, the writing instrument according to the present invention slides between the ink tank accommodating the ink in a free state and the pen tip member by the pressing member slidable in the longitudinal direction. In a writing instrument having a valve member that opens and closes an ink passage by being elastically deformed by receiving power, an ink passage wall portion of the valve member has a longitudinal overlapping portion. Therefore, even if the inside of the ink tank is pressurized, ink is prevented from seeping into the ink passage of the valve, or opening the ink passage when the pressure is high. This is to prevent bottling and the like.

[Brief description of the drawings] FIG. 1 is a cross-sectional view illustrating an example. FIG. 2 is an enlarged sectional view of a portion I in FIG. 1; FIG. 3 is a view taken in the direction of arrow II in FIG. 2; FIG. 4 is a diagram corresponding to FIG. 2 of another example. FIG. 5 is a diagram corresponding to FIG. 2 of still another example. [Explanation of symbols] A writing implement 1 shaft cylinder 2 inner hole 3 Pen tip holder 3a Rib around the circumference 3b slit 3c center hole 4 convex part 5 pen tip 6 Valve members 6a Fixed leg 6b Deformation part 6c Ink passage 6d overlap 6e groove 6f notch 7 Ink tank side opening 8 Pen tip side opening

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B43K 5/00-8/24

Claims (1)

(57) [Claim 1] Between a pen tip member and an ink tank that stores ink in a free state inside, it is elastically subjected to a sliding force by a pressing member slidable in a longitudinal direction. A writing instrument comprising a valve member that opens and closes an ink passage by intermittently deforming, wherein the ink passage wall of the valve member has a longitudinal overlapping portion.