JPH074073U - Writing instrument - Google Patents

Abstract

(57) [Summary] [Purpose] To enable smooth ink circulation in the ink guide core. [Structure] A cylindrical covering portion 3 that is harder than the ink guide core 2 is provided on the outer circumference of the ink guide core 2. The ink guide core 2 is fitted into the through hole 41 via the tubular covering portion 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a writing instrument. More specifically, an ink reservoir member is provided between the pen tip portion and the ink reservoir to temporarily hold the overflowing ink according to the increase in the internal pressure of the ink reservoir, and the shaft center of the ink reservoir member. The present invention relates to a writing instrument in which an ink guide core is inserted into a through hole provided in the.

[0002]

[Prior art]

 A conventional writing instrument of this type has a structure in which an ink guide core is press-fitted into an inner wall of a rear end of a through hole of an ink reservoir member, as disclosed in Japanese Utility Model Publication No. 55-32787.

The ink guide core is composed of a fiber focusing core having a capillary force or an open-cell plastic core, and when these are press-fitted into the through hole, they are fitted at the press-fitting fitting position. It deforms in the radial direction and hinders smooth ink circulation.

In addition, as an attempt to solve the above-mentioned problems, Japanese Utility Model Publication No. 4-52066 discloses that the ink outflow performance to the writing tip is improved even if the capillary force varies due to deformation of the ink induction core due to pressure fixing. In order to reduce the influence on it, there is disclosed a configuration in which the pressurizing and fixing portion is provided at the rear end portion of the through hole which is located far from the writing tip. However, the above-mentioned configuration may improve the ink outflow performance to some extent as compared with the case where the pressure fixing portion is provided near the tip of the writing, but the ink flowability at the pressure fixing portion is inevitable.

[0005]

[Problems to be solved by the device]

 The present invention solves the above-mentioned conventional problems, and even if the ink guide core is press-fitted at any position in the through hole of the ink reservoir member, the ink outflow inhibition due to the deformation of the ink guide core is also prevented. The aim is to provide a writing instrument that does not generate and allows smooth ink outflow.

[0006]

[Means for Solving the Problems]

 In the present invention, an ink reservoir member 4 for temporarily holding overflow ink according to an increase in internal pressure of the ink reservoir 11 is arranged between the pen tip portion 21 and the ink reservoir 11, and the ink reservoir member 4 is provided. A writing instrument having an ink guide core (2) inserted into a through hole (41) provided in the shaft center of a reservoir member (4), wherein a cylindrical coating portion (3) harder than the ink guide core (2) is provided on the outer periphery of the ink guide core (2). It is a requirement that the ink guide core 2 is fitted into the through hole 41 through the tubular covering portion 3.

The ink guide core 2 is provided with, for example, a fiber bundle, a resin processed body of the fiber bundle, a plastic porous body, an axial ink lead-out hole having a capillary force, or an axial slit provided on the outer periphery. Examples include plastic molded bodies.

The tubular covering portion 3 is preferably attached to the outer periphery of the ink guide core 2 by fusion, welding, adhesion or the like. Further, as the material of the cylindrical covering portion 3, polyacetal resin, synthetic resin such as polypropylene resin, or metal is effective.

[0009]

[Action]

 Since the cylindrical covering portion 3 is made of a hard synthetic resin, it can be securely fitted into the through hole 41 with a slight fitting margin. Moreover, as a result, the tubular covering portion 3 is hardly deformed in the radial direction. That is, even though the ink guide core 2 is press-fitted into the through hole 41, the ink guide core 2 inside the cylindrical covering portion 3 is hardly deformed in the radial direction, so that the ink outflow performance is not adversely affected. It enables smooth ink ejection.

[0010]

【Example】

 Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show an embodiment.

An ink reservoir member 4 is attached to a front portion of the shaft cylinder 1, and an ink storage portion 11 for storing raw ink is formed in a rear portion thereof. The ink reservoir member 4 is a conventionally known member that temporarily holds the overflowing ink according to the increase in the internal pressure of the ink reservoir 11 to prevent dripping. In the present embodiment, the ink reservoir member 4 is of a type in which a plurality of comb teeth are formed on the outer circumference, and axially slit-like ink grooves 42 and air concave grooves 43 are provided in the comb teeth. Has been done.

Further, the ink reservoir member 4 is provided with a straight through hole 41 at the axial center thereof, and the ink guide core 2 is press-fitted into the through hole 41. The ink guide core 2 is an extruded product made of a soft synthetic resin such as a polyester elastomer, an ethylene-vinyl acetate copolymer, a polyurethane, a polyamide resin or the like, and having an ink lead-out hole 22 formed axially therethrough. A cylindrical coating portion 3 made of a hard synthetic resin (here, polyacetal resin) is provided on the outer periphery of the ink guide core 2. The cylindrical covering portion 3 is ground like a brush at the tip of the ink guiding core 2 to expose the internal ink guiding core 2 as a pen tip portion 21. Further, a locking step portion 31 is provided on the cylindrical covering portion 3 behind the pen tip portion 21 and is in contact with the tip end portion of the ink reservoir member 4. A large diameter portion 32 that is press-fitted into the inner wall of the through hole 41 is provided behind the locking step portion 31. The large-diameter portion 32 is formed thick so as to prevent further radial deformation. Behind the large diameter portion 32, a small diameter portion 33 is provided up to the vicinity of the rear end of the ink guiding core 2 and is loosely inserted in the through hole 41. The rear end of the ink guide core 2 is ground in a taper shape to remove the cylindrical covering portion 3 and the ink lead-out hole 22 is opened in the radial direction.

The large diameter portion 32 is press-fitted at the tip of the inner wall of the through hole 41. Therefore, when the ink guide core 2 is inserted into the through hole 41 from the front, the moving length from the start of fitting the ink guide core 2 to the inner wall of the through hole 41 to the end of fitting can be reduced. As a result, reliable insertion is possible. Further, although not shown, a fitting rib or protrusion may be provided on the outer peripheral surface of the large diameter portion 32.

An annular protrusion 44 is provided at the tip of the ink reservoir member 4, and a tapered tip holding cylinder 5 is attached to the annular protrusion 44. The tip holding cylinder 5 is provided with four planar ribs 51 on the inner peripheral wall thereof, and the planar ribs 51 hold the outer periphery of the tubular covering portion 3 behind the pen tip portion 21 in pressure contact.

FIG. 4 shows another embodiment. From the rear end of the ink guide core 2 to the rear end of the large diameter portion 32, the cylindrical covering portion 3 is removed, and the ink lead-out hole 22 is opened in the radial direction. Easy to introduce. Other configurations are the same as those in FIG.

[0016]

[Effect of device]

 The writing instrument of the present invention has the structure described above, which has a structure in which the ink guide core is hardly deformed in the radial direction even though the ink guide core is press-fitted into the through hole of the ink reservoir member. The ink can be supplied smoothly without impairing the ink outflow performance from the pen tip to the pen tip, and the ink is abundantly ejected from the pen tip, and no break in handwriting occurs.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a front view of an ink guide core having the tubular covering portion of FIG.

FIG. 4 is a front view of an ink guide core having a tubular covering portion according to another embodiment.

[Explanation of Codes] 1 Shaft cylinder 11 Ink storage part 2 Ink lead core 21 Pen tip part 22 Ink outlet hole 3 Cylindrical covering part 31 Locking step part 32 Large diameter part 33 Small diameter part 4 Ink reservoir member 41 Through hole 42 Slit-shaped ink groove 43 Air concave groove 44 Annular protrusion 5 Chip holding cylinder 51 Planar rib

Claims (1)

[Scope of utility model registration request] 1. An ink reservoir member 4 for temporarily holding overflow ink according to an increase in internal pressure of the ink reservoir 11 is arranged between a pen tip portion 21 and the ink reservoir 11, and the ink reservoir is provided. The ink guiding core 2 is inserted into the through hole 41 provided at the axial center of the member 4.
In the writing instrument in which the ink guiding core 2 is inserted, a cylindrical covering portion 3 that is harder than the ink guiding core 2 is provided on the outer periphery of the ink guiding core 2, and the ink guiding core 2 is provided with the through hole 41 through the cylindrical covering portion 3.
A writing instrument characterized by being fitted inside.