JP4010075B2 - Writing instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a writing instrument that uses a pipe body as an ink tank and accommodates the pipe body.
[0002]
[Prior art]
Conventionally, a writing instrument that stores ink in an ink tank in a free state is called a so-called raw ink type writing instrument, and has advantages such as abundant fresh ink ejection and consumption of a large amount of ink without waste. Yes. In such a raw ink type writing instrument, it is necessary to consider in particular that there is no ink leakage.
In the writing instrument using ink, the inside of the ink tank is depressurized by the volume of the ink discharged for writing, except for a special tool in which the inside of the ink tank is pressurized. If the pressure in the ink tank is reduced, the ink supply to the pen tip will be adversely affected. Therefore, it is necessary to take air into the ink tank, and the ink chamber and the air chamber should be partitioned with a moving stopper. However, in the end, it is the same in that air is taken into the ink tank member, and most writing instruments using ink adopt this structure. The above-mentioned raw ink-type writing instruments are also the same, so the pipe body that opens both ends that can perform the function of discharging ink at one end and taking in air at the other end of the ink tank is sufficient with a very simple shape It is in the form of fulfilling the effect.
[0003]
[Problems to be solved by the invention]
However, a general synthetic resin-made extruded product or a metal pipe body can be obtained by cutting one long pipe every required length. For this reason, it is difficult to make the entire length dimension the same as in the case of an injection molded product using a mold. Variation in the overall length of the pipe body leads to variation in the accommodation position of the pipe body. If the length is too short, a space is created between the rear end of the pipe body and the fixing member, and the pipe body may move backward due to impact such as when the writing instrument is dropped. There is a risk of leakage. If the length is long, the pipe body protrudes from the accommodation position and cannot be accommodated in the writing instrument, or excessive contact force acts on the pipe body due to forcible accommodation, causing deformation and breakage.
[0004]
[Means for Solving the Problems]
That is, the present invention provides a writing instrument that houses a pipe body that opens at both ends as an ink tank that contains ink in a free state, and has one end of the opening of the pipe body as an ink discharge port for a pen tip, The end is used as an air intake for the inside of the ink tank, and a plug member having a ventilation path is press-fitted and arranged in the air intake so as to be movable inward by an external force, and the stopper is brought into contact with the plug member by contacting the plug member. A gist is a writing instrument in which a member is moved in an ink tank and the pipe body is fixed in a sandwiched state.
[0005]
[Action]
The overall length of the pipe body is set short, so that the pipe body does not protrude beyond the installation position. Then, the overall length of the pipe body and the plug member press-fitted and disposed therein is set larger than the installation range. As a result, when the pipe body to which the plug member is attached is accommodated in the writing instrument, the plug member formed by press-fitting into the air intake port of the pipe body comes into contact with the fixed member, and the plug member moves toward the inside of the ink tank. Let The stopper member moves toward the inside of the ink tank to absorb variations in the overall length of the pipe body. For this reason, generation | occurrence | production of the space between a plug member and a fixing member, the unaccommodation of a pipe body, and the excessive contact force to a pipe body can be prevented.
[0006]
【Example】
Hereinafter, an example will be described with reference to the drawings.
FIG. 1 shows a pipe body in which a chip 3 comprising a ball 1 as a writing member and a ball holder 2 that holds the ball 1 partially protruding from the tip is contained in an ink 4 in a free state. 5 is an example of a so-called ballpoint pen connected to the tip of 5.
The tip 3 and the pipe body 5 are both liquid-tightly connected to the tip holder 6 to constitute a ballpoint refill. Further, this ball-point pen refill is housed in a shaft cylinder 8 which is an injection molded product of acrylonitrile styrene resin having air holes 7 on the side wall, and is inserted into the tip end of the tip 9 of the tip 9 screwed to the tip of the shaft cylinder 8. Protruding.
[0007]
The pipe body 5 that accommodates the ink 4 contains therein a high-viscosity fluid 10 that is a gelled product such as α-olefin or polybutene as a moving plug that follows the movement of the ink interface in addition to the ink 4. The pipe body 5 is an extruded product of polypropylene resin, and both ends are cut. At this time, the entire length of the pipe body 5 is cut short to prevent the pipe body 5 from protruding from the accommodation position. The opening that is located in front of one end of the pipe body 5 that has been cut serves as an outlet for discharging the ink 4 into the ballpoint pen tip 3, and the opening that is located on the other rear end side is the pipe. It becomes a mouth that takes air into the body 5. A plug member 11 is press-fitted into the rear end opening.
[0008]
The plug member 11 is a cylindrical molded product having a vent hole 12 for not sealing the space behind the high viscosity fluid 10 in the pipe body 5. The rear end protrudes from the rear end of the pipe body 5 and is in contact with a stepped portion 14 formed in the inner hole of the tail plug 13 attached to the rear end of the shaft tube 8. In order to prevent the vent hole 12 of the plug member 11 from being sealed with the inner wall of the tail plug 13, a notch hole 15 is disposed in the step portion 14 of the tail plug 13. And the air hole 7 of the shaft cylinder 8 communicate with each other so that air can be taken in along with ink discharge.
[0009]
Further, the tip holder 6 located at the front part of the ballpoint pen refill is adapted to abut against the inner wall of the tip 9 and the ballpoint refill as a whole is sandwiched between the tip 9 and the tail plug 13. . Here, the length from the contact portion of the tip holder 6 to the tip 9 to the contact portion of the plug member 11 to the tail plug 13 via the pipe body 5 is adjusted from the tip 9 which is each contact portion to the tail. It is set larger than the accommodation position range up to the stopper 13. That is, when the pipe body 5 to which the plug member 11 is attached is accommodated in the writing instrument, the plug member 11 has a positional relationship in which the plug member 11 always comes into contact with the step portion 14 of the inner wall of the tail plug 13. Therefore, the plug member 11 is pushed and held in the pipe body 5 so as to be in an appropriate length. Therefore, even if there is a variation in the overall length of the pipe body 5 at the stage where both ends are cut, the plug member 11 that is press-fitted with the plug member 11 that is a ballpoint pen refill is connected to the tail plug 13. It is pushed by the stepped portion 14 and can move toward the inside of the pipe body 5, and variation in the overall length of the ballpoint pen refill can be suppressed.
[0010]
FIG. 2 shows another example. This is basically the same as the example shown in FIG. 1 and is an example of a ballpoint pen. However, a plurality of protrusions 16 projecting radially on the side wall of the plug member 11 are formed in the tail plug 13 without forming the notch hole 15 that connects the vent hole 12 of the plug member 11 and the air hole 7 of the shaft cylinder 8. The gap formed between the side wall on which the projection 16 is not disposed and the step 14 on the inner wall of the tail plug is formed between the vent hole 12 of the plug member 11 and the shaft cylinder. Air passages communicating with the eight air holes 7 are used. Further, the protrusion 16 also serves as a stopper that prevents the entire plug member 11 from entering the inside of the pipe body 5, and the plug member 11 as a whole is dropped when the pipe body 5 is assembled before the pipe body 5 is accommodated. 5 It is possible to prevent such a problem that it enters the inside direction and the reworking becomes ineffective. In addition, it is the same as the above-described example that variation in the overall length of the ballpoint pen refill can be suppressed.
[0011]
FIG. 3 shows still another example. The valve mechanism is opened and closed as the pen core 17 made of a fiber converging body capable of sliding the ink 4 stored in a free state within a predetermined range is opened, so that ink derivation control to the pen core 17 is performed. It is an example of a nib-knock-type raw ink valve-type writing instrument.
A rear shaft 19, which is a bottomed cylindrical body, is fixed to the rear end of the pen core holder 18 that accommodates the pen core 17 by concave and convex fitting, and the bottom portion 20 serves as a portion that defines the accommodation position of the pipe body 5. The rear shaft 19 is an injection molded product of acrylonitrile styrene resin. Also, inside the rear shaft 19 is accommodated a pipe body 5 obtained by extruding a polypropylene resin as an ink tank for containing the ink 4 in a free state, and then cutting both ends with the entire length of the pipe body shortened. Yes.
In the pipe body 5, a high-viscosity fluid 10 made of α-olefin or polybutene that follows the movement of the ink 4 and the ink interface and the high-viscosity fluid 10 are disposed between the inner wall of the pipe body 5. The floating plug 21 is accommodated.
[0012]
A valve member 22 made of an elastic material is disposed behind the inner hole of the pen core holder 18. The valve member 22 has a slit-like ink passage 23. The ink passage 23 is liquid-tightly closed in a state where no external force is applied, and the ink is prevented from being led from the ink tank to the pen core 17. The slit-shaped ink passage 23 is opened by pressing the rear end of the pen core 17 slidable back and forth. Further, the valve member 22 made of an elastic material is a seal member that is in contact with the inner hole of the pipe body 5 to form liquid tightness. The material is silicon rubber, ethylene propylene rubber, styrene butadiene rubber, butadiene. Examples thereof include rubber, nitrile rubber, urethane rubber, and butyl rubber.
[0013]
As shown in FIG. 4, which is an enlarged view of the portion I in FIG. 3, a plug member 11 is pressed into the rear end opening of the pipe body 5 so as to protrude rearward. The plug member 11 includes a large-diameter portion 24 whose outer peripheral portion is in pressure contact with the inner wall of the pipe body 5 and a small-diameter portion 25 that is a portion protruding from the rear end of the pipe body 5. It penetrates through the ventilation hole 12 so as not to seal the space behind 21. Further, the step portion 26 formed between the large diameter portion 24 and the small diameter portion 25 is flush with the rear end of the pipe body 5, so that the large diameter portion 24 is attached to the pipe body before the rear shaft is attached. 5 can be positioned.
Further, a notch hole 27 is formed in the rear end opening portion of the vent hole 12, and even when the rear end of the plug member 11 comes into contact with the bottom portion 20 of the rear shaft 19, the air hole 7 of the rear shaft 19 is interposed. And communicate with the outside air.
[0014]
In a state before the rear shaft 19 is attached, the total length of the pipe body 5 and the plug member 11 press-fitted and disposed in the pipe body 5 is set larger than the housing position range from the valve member 22 to the bottom 20 of the rear shaft 19. . As a result, when the rear shaft 19 is attached to the pen core holder 18 to which the pen core 17 and the valve member 22 are accommodated and the pipe body 5 to which the plug member 11 is attached is connected, it is press-fitted into the air intake port of the pipe body 5. The stopper member 11 is formed so as to always contact the bottom portion 20 of the rear shaft 19. Therefore, similarly to the above-described example, even if there is a variation in the overall length of the pipe body 5, the plug member 11 press-fitted into the pipe body 5 can move toward the inside of the pipe body 5. [0015]
Here, the plug member 11 is formed of polymethyl methacrylate having a Rockwell R hardness of 102 degrees or more, which is harder than 98 degrees of the pipe body 5. This is for the pipe body 5 to be expanded in diameter when the plug member 11 is press-fitted into the pipe body 5, so that the press-fitting movement of the plug member 11 is smooth, but has the same degree of hardness. Alternatively, the plug member 11 may be a member softer than the pipe body 5.
[0016]
【The invention's effect】
As described above, the writing instrument of the present invention suppresses variations in the accommodation position of the pipe body as much as possible, and prevents problems such as ink leakage, inability to accommodate, deformation, and damage.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part showing an example.
FIG. 2 is a longitudinal sectional view of an essential part showing a modification.
FIG. 3 is a longitudinal sectional view of a main part showing another example.
4 is an enlarged view of a portion I in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ball 2 Ball holder 3 Tip 4 Ink 5 Pipe body 6 Tip holder 7 Air hole 8 Shaft tube 9 Lead metal 10 High viscosity fluid 11 Plug member 12 Vent hole 13 Tail plug 14 Step part 15 Notch hole 16 Projection 17 Pen core 18 Pen Core holder 19 Rear shaft 20 Bottom portion 21 Floating plug 22 Valve member 23 Ink passage 24 Large diameter portion 25 Small diameter portion 26 Step portion 27 Notch hole

Claims (2)

In a writing instrument containing a pipe body that opens at both ends as an ink tank that contains ink in a free state, one end of the opening of the pipe body serves as an ink discharge port for the pen tip, and the other end to the inside of the ink tank A plug member having an air intake passage is press-fitted and arranged in the air intake port so as to be movable inward by an external force, and the stopper member is brought into contact with the stopper member by the contact between the fixing member and the stopper member. A writing instrument in which the pipe body is fixed in a clamped state.   2. The pipe body is a molded pipe made of polypropylene resin, the end portion is formed by cutting, and the plug member is made of a material harder than the pipe body in Rockwell R hardness. Writing instruments.

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