JP4302845B2 - The tip of the writing instrument and the mechanical pencil to which the tip is connected - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a front end of a mechanical pencil, a ballpoint pen, or the like, in particular, a front end configured as a separate member from a shaft cylinder and a mechanical pencil to which the front end is connected .
[0002]
[Prior art]
2. Description of the Related Art Conventionally, among members constituting a writing instrument, there is a cap provided with a safety measure that prevents suffocation when an infant accidentally swallows it and clogs it in his throat.
The cap can be easily obtained by an infant, so that it is not accidentally swallowed and clogged in the throat, so that it does not suffocate JIS standard S6060 (a writing / marking tool for children up to 14 years of age). Safety standards are defined by (Cap-Safety Requirements), and caps having various air flow passages have been proposed.
However, the front end of the writing instrument is not limited to the safety standards as described above, and there is no one provided with an air flow passage for safety measures. This is because the tip of the writing instrument is screwed into the shaft tube, so it cannot be removed as easily as the cap. This is probably due to the fact that
[0003]
However, there is a concern that the conventional tip of a writing instrument may be clogged in the throat due to the relationship between the outer diameter of the writing instrument and the inner diameter of the infant's trachea. In particular, in the case of the tip of a mechanical pencil, the infant removes from the barrel. In addition, the through-hole through which the core is inserted has a small inner diameter and does not allow sufficient air to circulate when clogged in the throat. Moreover, even if a slight air flow rate can be ensured by the through hole, the core may be broken and clog the through hole when the tip is removed. Thus, it is necessary to ensure an air passage for emergency breathing even at the front end of the writing instrument.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described conventional circumstances, and the purpose of the process is to ensure time for emergency treatment even if an infant accidentally swallows and clogs the throat. An object of the present invention is to provide a front end of a writing instrument excellent in safety and a mechanical pencil to which the front end is connected .
[0005]
[Means for Solving the Problems]
The technical means of the present invention for solving the above-mentioned problems is an air flow that is configured as a separate member from the shaft tube and ensures the air flow on the side wall at the front end of the writing instrument having a maximum outer diameter of 6 mm to 16 mm. A road is provided.
Here, the air flow passage means a vent hole that is opened so as to pass through the inner and outer sides of the front opening, a ventilation groove formed on the outer peripheral surface of the front opening, and the like.
According to the above technical means, even if an infant accidentally swallows and clogs his throat, the air flow passage allows air for breathing to circulate.
[0006]
Further, in the above configuration, if the air flow passage is formed so as to ensure an air flow rate of 8 liters / minute or more, a sufficient flow rate of air that does not suffocate even if accidentally swallowed and clogged in the throat can be circulated. .
In the above configuration, if the air flow passage has one open end on the outer peripheral surface of the tip and the other open end on the connecting portion of the shaft tube, In the state where the mouth is mounted on the shaft cylinder, the air flow passage can be blocked to prevent foreign matter from entering the front mouth.
Here, the connecting portion of the shaft tube means a portion that is blocked when connected to the shaft tube. For example, when the front end is attached to the shaft tube, In addition, a portion where the front end face of the grip abuts is included.
Furthermore, if the tip having the above-described configuration is formed of a thermoplastic resin, the air flow passage can be easily formed by resin molding.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show an example of the tip of a writing instrument according to the present invention, and FIG. 3 shows an example of a writing instrument to which the tip is applied.
[0008]
The tip 10 is a molded part having a substantially inverted conical shape made of thermoplastic resin, and has a maximum outer diameter D of 6 mm to 16 mm at the upper end, and two axisymmetric air flow passages 11, 11 is formed. And it is assembled | attached to the writing instrument A (mechanical pencil) mentioned later.
Further, the tip 10 is formed in a hollow shape, a female screw portion 14 is formed on the inner peripheral surface thereof and the front end portion of the shaft cylinder 21 of the writing instrument A is screwed, and a core made of an elastic member is formed on the front end side. The holder 13 is mounted, and the core guide tube 12 is fitted to the foremost end so that the tip is exposed, thereby constituting a part of the core feeding mechanism in the writing instrument A (mechanical pencil).
[0009]
The lower limit of the maximum part outer diameter D is set to 6 mm. If the maximum part outer diameter D is a small tip that is less than 6 mm, the tip is clogged even if an infant accidentally swallows it. This is because there is no danger of suffocation because it is not allowed to form, and molding is difficult and impractical.
[0010]
The upper limit of the maximum outer diameter D is set to 16 mm in JIS standard S6060 (caps for writing / marking tools for children up to the age of 14-safety requirements). (Dimension tolerance: upper limit +0.05 mm, lower limit -0 mm) When the cap is inserted into the gauge so that it is perpendicular to the ring gauge, the cap length of 5 mm or more remains without passing freely. Considering that the cap is too large and there is no danger of inhalation, it is considered that there is no danger of inhalation even when the outer diameter exceeds 16 mm even at the tip of the writing instrument. Because it is.
[0011]
As shown in FIG. 1B, the air flow passage 11 forms a stepped portion 10b by making the side wall of the tip 10 into a notch shape, and one open end portion of the stepped portion 10b. 11b facing downward. The other opening end portion 11a of the air flow passage 11 has an upward surface on the surface 10a in the tip 10 where the front end surface of the shaft tube 21 abuts when the tip 10 is mounted on the shaft tube 21. . That is, the air flow passage 11 is a vent hole in the vertical direction (axial direction) through which air flows inside and outside the tip 10, and has a cross-sectional area that can ensure a predetermined air flow rate.
[0012]
The air flow rate is set to 8 liters / minute or more, and this value is based on the air flow rate defined by the JIS standard S6060 (cap for writing / marking tools for children up to 14 years old-safety requirement). In the air flow test of the annex of the same standard, the cap was simply replaced with the tip 10, and the axial direction when measured under conditions of a maximum pressure difference of 1.33 kPa and room temperature (about 23 ° C.) The value of the air flow rate to
That is, according to the safety requirements of the above JIS standard, it is considered that there is no danger of suffocation if an infant can clog a cap in its throat and an air flow rate of 8 liters / minute or more can be secured. Even when the front port 10 is used, it is considered that the danger of suffocation can be avoided if the same air flow rate can be secured.
[0013]
In the case of a cap, the ventilation area that can secure the air flow rate is defined as “6.8 mm 2 or more” in the JIS standard S6060. By setting the total ventilation area of the passages 11 and 11 to 6.8 mm 2 or more, the air flow rate can be secured. However, in practice, the air flow rate varies depending on the difference in flow resistance depending on the shape and number of air flow passages. For example, when the number of air flow passages is large, the flow resistance increases and the air flow rate decreases. Therefore, in the embodiment of the present invention, it has been confirmed by experiments that the air flow rate is 8 liters / minute or more.
[0014]
3A, the front end 10 is screwed into the front end portion of the shaft tube 21. At this time, the opening end portion 11a of the air flow passage 11 is closed by the front end surface of the shaft tube 21. The writing instrument A is constructed by being assembled so as to be peeled off.
The writing instrument A is a mechanical pencil having a known lead feeding mechanism in which the chuck 31 feeds the lead 40 in the lead tank 34 by a predetermined length by knocking a rear end knock portion (not shown) of the shaft cylinder 21. It is. In the figure, reference numeral 33 denotes a spring that urges the lead tank 34 rearward, reference numeral 32 denotes a clutch that slides in the axial direction on the outer periphery of the chuck 31, and reference numeral 22 denotes a grip that is attached to the outer periphery of the shaft cylinder 21 to prevent slippage. is there.
[0015]
Thus, according to the front opening 10 having the above-described configuration, the opening end portion 11a of the air flow passage 11 is connected to the shaft tube in the state assembled to the front end portion of the shaft tube 21 as shown in FIG. Since the front end surface of 21 is blocked, foreign matter such as dust or dust does not enter the front opening and obstruct the lead feeding operation.
When the tip 10 is removed from the front end portion of the shaft tube 21 due to an infant's mischief or the like, as shown in FIG. Since the part 11a is opened, even if the infant accidentally swallows and clogs his throat, the air flow passage 11 circulates breathing air to prevent the infant from suffocating.
[0016]
In the illustrated example, two air flow passages 11 are provided on the side wall of the tip 10. However, the number and shape of the air flow passages 11 are not limited as long as the predetermined air flow rate can be secured.
[0017]
【The invention's effect】
According to the present invention, even if an infant accidentally swallows and clogs the throat, the air flow passage circulates the air for breathing, so assuring time for first aid and preventing suffocation of the infant It is possible to provide a tip of a writing instrument excellent in safety in an emergency.
Furthermore, if the air flow passage is formed so as to ensure an air flow rate of 8 liters / minute or more, a sufficient air flow rate that does not suffocate even if accidentally swallowed and clogged in the throat can be circulated.
In addition, the air flow passage has one opening end portion on the outer peripheral surface of the tip opening, and has the other opening end portion at a connecting portion of the shaft tube, so that the tip opening has a shaft. In the state of being attached to the cylinder, it is possible to prevent foreign matters such as dust and dirt from entering the tip. For example, in the case of a mechanical pencil, foreign matter intrudes into the front opening, so that the lead feeding operation is not hindered.
Furthermore, by forming the tip with a thermoplastic resin, it is possible to easily form the air flow passage and to provide a tip of a writing instrument that is excellent in productivity.
[Brief description of the drawings]
FIG. 1 shows an example of a front end of a writing instrument according to the present invention, in which (a) is a front view, and (b) is a side view with a main part cut away.
FIG. 2A is a top view of the tip opening, and FIG. 2B is a bottom view of the tip opening.
FIGS. 3A and 3B show an example of a writing instrument to which the tip is applied, wherein FIG. 3A is a longitudinal sectional view, and FIG. 3B is a longitudinal sectional view of a state in which the tip is removed from a shaft cylinder.
[Explanation of symbols]
10: Front port 11: Air flow passage 11a: Open end 11b: Open end A: Writing instrument D: Maximum outer diameter

Claims (3)

In the tip of the writing instrument that is configured as a separate member from the shaft cylinder and has a maximum part outer diameter of 6 mm to 16 mm, an air flow passage that secures air flow is provided on the side wall ,
The air flow passage has one opening end portion on the outer peripheral surface of the tip, and the other opening end portion at a connecting portion of the shaft tube,
A front end of a writing instrument , wherein an opening area of the air flow passage gradually increases in a centrifugal direction of the front end from the other opening end to the one opening end . 2. The leading edge of a writing instrument according to claim 1 , wherein the air flow passage has the one opening end portion in a stepped portion provided by partially cutting a substantially inverted conical side wall. .   In the mechanical pencil formed by connecting the tip of the writing instrument according to claim 1 or 2 to the shaft tube,
  A mechanical pencil characterized in that the other opening end is closed by a front end surface of the shaft cylinder.

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