JPH0858282A - Direct liquid type writing utensil - Google Patents

Abstract

PURPOSE: To strengthen shock resistance of direct liquid type writing utensils at the time of dropping the same and secure good flow of ink, by a method wherein a difference between the inner diameter of a shaft cylinder and the outer diameter of a columnar body is specified. CONSTITUTION: To harmonize shock resistance of writing utensils at the time of dropping the same on a floor with a flow of ink at the time of writing, a difference (clearance) between the inside diameter of a shaft cylinder 1 and outer diameter of a columnar body 5 is important. As a result of a test on a relation between the clearance and consumption of the ink per 100m handwriting, the consumption of the ink is at least 0.05g per 100m handwriting to enable reliable writing with a sufficient ink flow at the time of writing. To satisfy this condition, it is necessary that the difference between the inner diameter of the shaft cylinder 1 and the outer diameter of the columnar body 5 is at least 1.0mm. When the difference between the inner diameter of the shaft cylinder 1 and the outer diameter of the columnar body 5 is not exceeding 1.5mm, the ink does not flow out of a tail end opening even if the writing utensils are dropped from a height of 1m and shock resistance can be obtained. Therefore, the shock resistance can be strengthened and the sufficient ink flow can be secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct liquid type writing instrument in which ink is directly filled in a barrel having a pen body at its tip.

[0002]

2. Description of the Related Art For example, a ballpoint pen using water-based ink has been put into practical use which is a batting type in which ultrafine fibers are aligned and formed into a rod shape to absorb the ink, and the batting is housed in a barrel. However, this filling material has the problem that the writing capacity is short due to the limited storage capacity of the ink, and the end point at which the writing becomes impossible due to exhaustion of the ink is difficult to understand.

On the other hand, the direct liquid type writing instrument in which the ink is directly filled in the barrel and does not use the batting has the advantage that the end point is clear and the writing distance is long because the ink can be directly visually inspected. In such a direct liquid writing instrument, when the air in the barrel becomes hot and expands, the ink is excessively ejected and drops, so that the excessively ejected ink is temporarily stored to prevent the ink from dropping. Many of the pen cores have a gas-liquid exchange function for introducing air into the barrel due to the consumption of the pen core, but the pen core has a complicated structure and a large number of parts.

Therefore, the tail end side of the shaft cylinder whose tail end communicates with the outside air is sealed with a paste-like backflow preventive body, and ink is filled in front of the backflow preventive body so that the pen body and the backflow preventive body are connected to each other. It has been put into practical use that the gap is filled only with ink and the backflow preventer moves forward as the ink is consumed. In other words, the backflow preventer prevents the backflow of ink and prevents it from flowing out from the tail end opening of the barrel, but since there is only ink and no air in front of the backflow preventer, it becomes hot. The ink is not pushed out by the expanded air.

Even in such a direct liquid type writing instrument, there is a great demand for increasing the writable distance, and it has been attempted to increase the inner volume of the barrel. However, when the tail end side of the barrel is sealed with a paste-like backflow preventer, if the inner diameter of the barrel is increased, the sealing ability of this backflow preventer decreases, and when the writing implement falls on the floor, etc. Ink will be washed away from the rear end opening of the barrel. Therefore, in a direct liquid type writing instrument in which the tail end side of the shaft cylinder is sealed with a paste-like backflow preventive body, the inner diameter of the shaft cylinder is limited to at most 4 mmφ, and there is a limit in extending the writable distance. .

For this reason, the tail end side of the shaft cylinder is sealed by a columnar body around which a paste-like backflow preventing body is applied, and ink is filled in front of the columnar body so that the columnar body is consumed as the ink is consumed. A direct liquid writing instrument designed to move the body forward has been tried. In other words, even if the inner diameter of the barrel is large and the amount of ink filled is large, the gap between the inner peripheral surface of the barrel and the columnar body is narrow, and this narrow gap is sealed by the paste-like backflow preventer applied to the columnar body. Since it is stopped, it is strong against impact and ink can be prevented from flowing out from the tail end opening of the barrel.

[0007]

However, even in the direct liquid type writing instrument in which the tail end side of the barrel is sealed by the columnar body to which the paste-like backflow preventing body is applied, the inner peripheral surface of the barrel is also improved. It was found that it is necessary to properly select the gap between the columnar body, that is, the difference between the inner diameter of the barrel and the outer diameter of the columnar body.
That is, if the difference between the inner diameter of the barrel and the outer diameter of the columnar body is too large, the impact when dropped still becomes a problem. Conversely, if the difference between the inner diameter of the barrel and the outer diameter of the columnar body is too small, the ink The columnar body may not be completely advanced due to the consumption of the ink, and the ink may be incomplete and writing may not be possible.

Therefore, the present invention provides a direct liquid type writing instrument capable of enlarging the inner diameter of the shaft cylinder, having a long writing distance, being resistant to impact, and having sufficient ink discharge and capable of writing reliably. The purpose is to

[0009]

In order to achieve such an object, the present invention is such that ink is directly filled in a barrel having a pen body at its tip, and the tail end side of the barrel is pasted around the periphery. In a direct liquid writing instrument in which a columnar body is sealed with a column-shaped backflow prevention body, ink is filled in front of the columnar body, and the columnar body advances as ink is consumed, The difference in the outer diameter of the columnar body is 1.0 to 1.5 m
m.

[0010]

Since the tail end side of the barrel is sealed by the columnar body coated with a paste-like backflow preventer around the barrel, the inner diameter of the barrel can be increased and the writing distance becomes longer. Since the difference between the inner diameter of the column and the outer diameter of the columnar body is 1.0 to 1.5 mm, it is a direct liquid type writing instrument that is strong against impact, has sufficient ink output, and can be written reliably.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the embodiments shown in the drawings. In FIG. 1, the shaft cylinder 1 is made of a transparent synthetic resin and has an inner diameter of a mmφ, for example 7.0 mmφ.
The inner diameter is larger than that of the shaft cylinder of the conventional direct liquid writing instrument, and therefore a large amount of ink can be filled. Then, the tip 2 of the ballpoint pen is attached to the tip opening of the barrel 1.

The tip 2 is formed of stainless steel in a bullet shape, and is freely rotatable in a ball house at the tip of the tip 2 with a ball 3 made of cemented carbide protruding partially from the tip of the tip 2. Being hugged by. Inside the chip 2, a small spring 4 having a spring force of, for example, 40 g is arranged. The spring 4 repels the ball 3 to press it against the inward tip end edge 21 of the tip 2 to make contact with the ball 3 and the tip edge 21. Constitutes the valve mechanism. The pen body is not limited to the ball-point pen tip 2, and may be, for example, a fiber tip formed by molding fibers into a rod shape.

A tail plug 7 having an air hole 71 is fitted into the tail end opening of the barrel 1. Inside the tail end side of the shaft cylinder 1, a light columnar body 5 having a bottomed cylinder shape is arranged.
The columnar body 5 has an outer diameter of bmmφ, for example, 6mmφ and a length of 15 mm.
mm. Around the columnar body 5, a paste-like backflow preventing body 6 such as petrolatum is applied, and the backflow preventing body 6 fills the gap between the inner peripheral surface of the barrel 1 and the columnar body 5. That is, the tail end side of the shaft cylinder 1 is sealed by the columnar body 5 having the paste-shaped backflow preventive body 6 applied to the periphery thereof.

Aqueous ink I having a viscosity of, for example, 30 to 40 cps is filled in the barrel 1 in front of the columnar body 5, and no air is present in the barrel 1 in front of the columnar body 5. Then, when the ink I is consumed by writing, the columnar body 5 coated with the paste-like backflow preventing body 6 is moved forward accordingly. However, since the columnar body 5 is used, the inner diameter of the barrel 1 is reduced. It can be large and has a large internal volume, that is,
A large amount of ink I can be filled in the barrel 1, which has the advantage of a long writing distance.

As described above, in order to balance the impact resistance when the writing implement is dropped on the floor and the ink ejection during writing, the difference between the inner diameter of the barrel 1 and the outer diameter of the columnar body 5 (clearance). ) Is important, and the results of testing the relationship between this clearance, impact resistance when dropped on the floor, and ink discharge during writing will be described below.

A large number of writing instruments having the above-mentioned clearances changed were manufactured, and the clearances and handwritings 100
The relationship of ink consumption per m was tested and the results are shown in FIG. The ink consumption per 100 m of handwriting must be 0.05 g or more in order to be able to write with sufficient ink when writing, and in order to satisfy this condition, the inner diameter of the barrel 1 It is necessary that the difference in outer diameter between the columnar body 5 and the columnar body 5 is 1.0 mm or more. That is, if this difference is less than 1.0 mm, the columnar body 5 does not advance sufficiently during writing, ink is not sufficiently ejected, and reliable handwriting cannot be obtained.

Next, FIG. 3 shows the result of testing the relationship between this clearance and the height of the drop allowance when the writing implement is naturally dropped on the floor, and the shaded area is the drop allowance area. is there. In other words, in this region, even if the direct-writing type writing instrument is naturally dropped on the floor 10 times with the tail plug 7 facing downward, the backflow preventive body 6 hardly moves and the sealing function is perfect. Then, as this clearance increases, the drop height that can withstand the impact decreases, but as in the case of falling from the desk to the floor, the writing instrument often drops from a height of about 1 m, and the inner diameter of the barrel 1 If the difference between the outer diameters of the columnar body 5 and the columnar body 5 is 1.5 mm or less, the ink does not flow out from the tail end opening of the barrel even if it falls from a height of 1 m.
It is possible to obtain enough impact resistance to endure practical use.

[0018]

As described above, in the direct liquid type writing instrument of the present invention, the tail end side of the barrel is sealed by the columnar body to which the paste-like backflow preventing body is applied, so that Although the inner diameter can be increased and the writing distance becomes longer, the difference between the inner diameter of the barrel and the outer diameter of the columnar body is 1.0 to 1.5 mm, which is strong against impact when dropped and ink is not ejected. It is possible to provide a direct liquid type writing instrument capable of writing with sufficient and certainty.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a direct liquid writing instrument.

FIG. 2 is an explanatory diagram of a relationship between a difference between an inner diameter of a shaft cylinder and an outer diameter of a columnar body and an ink consumption amount.

FIG. 3 is an explanatory diagram of a relationship between a difference between an inner diameter of a shaft cylinder and an outer diameter of a columnar body and a drop allowable amount range.

[Explanation of symbols]

 1 Shaft cylinder 2 Ballpoint pen tip 3 Ball 4 Spring 5 Columnar body 6 Backflow prevention body 7 Tail plug

Claims (1)

[Claims] 1. An ink is directly filled in a shaft cylinder having a pen body at its tip, and a tail end side of the shaft cylinder is sealed by a columnar body having a paste-like backflow preventer applied to the periphery thereof. In addition, a direct liquid writing instrument in which ink is filled in front of the columnar body and the columnar body advances as ink is consumed, wherein the difference between the inner diameter of the barrel and the outer diameter of the columnar body is 1.0 to 1 .5m
A direct liquid writing instrument characterized by being m.