JP2003237282A - Retractable writing implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a gate mark from standing out, to protect the beautiful appearance of a casing, to prevent the movement of a refill from being hindered even when the gate mark is protruded, and to enough control the shake of a pen point during writing. <P>SOLUTION: The refill of a writing implement is housed in the casing 2. A tip opening 3 through which the pen point 5 of the refill passes is formed in the tip part 21 of the casing. The tip part 21 of the casing 2 is formed at least by the injection molding of a synthetic resin. A recessed part 31 is formed in a part of the opening end part of the inside surface of the tip opening 3. A gate part 32 for injection molding is formed in the recessed part 31. A support part 33 for supporting the outside surface of the refill (the front part 61 of a pen point holder) is formed in a part excluding the recessed part 31 of the opening end part of the inside surface of the tip opening 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a retractable writing instrument. More specifically, the present invention relates to a retractable writing instrument in which a writing instrument refill is housed inside a barrel and a tip opening through which the pen tip of the writing instrument refill can be projected and retracted is provided at the tip of the barrel. In the present invention, "front" refers to the tip mouth side, and "rear" refers to the opposite side.

[0002]

2. Description of the Related Art Conventionally, with this type of retractable writing instrument,
In Japanese Patent Laid-Open No. 10-236066, the gate mark is not conspicuous, the appearance is good, and even if the gate mark is slightly protruded, it does not affect the refill retracting operation. A configuration in which an opening portion for allowing a gate mark to appear is provided in an opening portion of a shaft tip opening (tip opening of the present invention), and a refill support hole portion (supporting portion of the present invention) is provided behind the opening portion. Is disclosed.

In the above conventional structure, the refill is
It is supported by the refill support hole at the rear of the opening, and the refill is not supported at the opening (that is, the opening end of the tip opening), so the pen tip wobbles and the writing feeling is unstable for the user. May be given.

Further, the portion where the writing tool refill comes into contact with the inner peripheral surface of the tip opening is the outer peripheral surface of the metal tip body or the outer peripheral surface of the synthetic resin nib holder which holds the tip body. There are cases. Among them, when the outer peripheral surface of the pen tip holder made of synthetic resin comes into contact with the inner peripheral surface of the tip end, the pen tip holder becomes soft and easily deformed. The wobble of the pen tip tends to occur.

Further, in the case where the pen tip is a ball-point pen tip (so-called needle tip) made of a straight cylindrical thin tube,
The nib itself becomes thin, and the wobbling of the nib when writing is
More likely to occur.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art, in which the gate mark is not conspicuous, the aesthetic appearance of the barrel is not spoiled, and the gate mark is projected. However, the present invention intends to provide a retractable writing instrument that does not hinder the refilling operation of the refill and, moreover, the wobble of the pen tip is sufficiently suppressed during writing and gives a stable writing feeling to the user.

[0007]

Means for Solving the Problems [1] The present invention relates to a shaft cylinder 2
The writing tool refill 4 is housed inside, and a tip port 3 through which the pen tip 5 of the writing tool refill 4 can be projected and retracted is provided at the tip 21 of the barrel 2, and the tip 21 of the barrel 2 is at least made of synthetic resin. The retractable writing instrument 1 is formed by molding, and a recess 31 is formed in a part of the opening end of the inner peripheral surface of the tip opening 3.
And a support portion for supporting the outer peripheral surface of the writing instrument refill 4 in a portion of the inner peripheral surface of the tip end opening 3 excluding the concave portion 31 provided with a gate portion 32 for injection molding. The requirement is to provide 33 (Claim 1).

By providing a support portion 33 for supporting the outer peripheral surface of the writing instrument refill 4 at a position on the inner peripheral surface of the opening end of the tip end port 3 excluding the concave portion 31, the writing instrument refill 4 is provided.
Since the outer peripheral surface of the pen can be supported at a position more forward than in the conventional case, the pen tip 5 does not wobble during writing. Further, since the gate portion 32 for injection molding is provided in the concave portion 31 of the tip end port 3, the gate mark is not conspicuous, the appearance of the barrel 2 is not impaired, and even if the gate mark is slightly projected. Since the gate mark does not contact the outer peripheral surface of the writing implement refill 4, the smooth retracting operation of the writing implement refill 4 is not hindered.

The support portion 33 is provided only on the inner peripheral surface of the open end portion of the front end opening 3, or the inner peripheral surface of the front end opening 3 behind the recess 31 from the inner peripheral surface of the open end portion of the front end opening 3. It may be configured to be continuously installed. In the circumferential range of the recess 31, the angle α from the center of the tip opening 3 is within 70 degrees (preferably 6).
It is preferable to set it within 5 degrees) from the viewpoint that the wobble of the pen tip 5 is sufficiently prevented.

[2] In the retractable writing instrument 1 according to claim 1, the support portion 33 is made of a metal nib (for example, a metal ballpoint pen tip, or a metal nib protection member that protects the outer circumference of the nib). The supporting portion 33 may support the outer peripheral surface, but the supporting portion 33 supports the outer peripheral surface of the pen tip holder 6 made of synthetic resin (claim 2).

When the outer peripheral surface of the pen tip holder 6 made of synthetic resin comes into contact with the support portion 33 at the time of writing, wobbling of the pen tip 5 at the time of writing tends to occur, but in combination with the structure of claim 1, The wobble of the pen tip 5 during writing can be sufficiently suppressed.

[3] In the retractable writing instrument 1 according to claim 1 or 2, the pen tip 5 is, for example, a metal ball-point pen tip having a large conical surface at its tip, a porous pen body, a fiber pen body, Any of mechanical pencils and the like may be used, but it is preferable that the pen tip 5 is a ball-point pen tip made of a straight cylindrical thin tube (claim 3).

When the pen tip 5 is a straight cylindrical thin tube,
Although the nib 5 itself becomes thin and wobbling of the nib 5 easily occurs during writing, the wobbling of the nib 5 during writing can be sufficiently suppressed in combination with the structure of claim 1. The ball-point pen tip made of a straight cylindrical thin tube is a thin tube having a uniform thickness behind the ball holding portion of the tip body. For example, the outer diameter of the thin tube is 2 m.
A thin tube of m or less (preferably 1.5 mm or less) is effective.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

1 to 5 show an embodiment of a retractable writing instrument 1 according to the present invention. FIGS. 1 and 2 show a pen tip protruding state, and FIGS. 3 to 5 show a pen tip retracting state.

As shown in FIGS. 1 and 2, in the retractable writing instrument 1 of this embodiment, the pen tip 5 of the shaft cylinder 2 is moved by pressing the knock portion 22 at the rear end of the shaft cylinder 2 forward. Tip opening 3
It is a writing instrument equipped with a rear-end knock-type retracting mechanism that protrudes and retracts from. The retractable writing instrument 1 mainly includes a barrel 2, a writing instrument refill 4 housed in the barrel 2, and a coil spring that biases the writing instrument refill 4 backward and is housed in the barrel 2. 9 and 9. The retractable mechanism may be, for example, a rotary type or a side knock type other than the rear end knock type.

The shaft tube 2 is a cylindrical body obtained by injection molding of synthetic resin (for example, polycarbonate, polyethylene terephthalate, polypropylene, etc.). The tip portion 21 of the shaft tube 2 is formed in a tapered shape, and the tip portion 2
The front end opening 3 is opened to the front. A clip 23 is provided on the outer surface of the rear end of the barrel 2 so as to project. In this embodiment, the tip portion 21 of the barrel 2 is integrally formed with the front portion of the barrel 2 behind the barrel 2 by injection molding of synthetic resin. Only one of them may be constituted by a separate member of the injection molded body of synthetic resin.

The writing tool refill 4 has a pen tip 5 and a pen tip holder 6 into which a rear portion 63 of the pen tip 5 is press-fitted and fixed.
And an ink containing tube 8 to which the rear end of the pen tip holder 6 is press-fitted and fixed.

The nib 5 is made of metal (for example, SUS).
304, made of austenitic stainless steel such as SUS321) and a chip body 51 made of a right cylindrical thin tube having a uniform thickness, and a ball 52 rotatably held at the tip of the chip body 51 (for example, The outer diameter is 0.5 mm or 0.7 mm). An annular inward edge portion 53 is formed at the tip of the tip body 51 by inward pressing deformation. Further, on the inner surface of the side wall of the chip body 51 behind the tip edge portion 53, a plurality of inward projecting portions 54 (that is, ball receiving seats) are formed at equal intervals in the circumferential direction by inward pressing deformation. The ball 52 is rotatably held between the inner surface of the tip edge portion 53 and the front surface of the inward protruding portion 54 (that is, the ball holding portion).

The outer diameter of the ball 52 is 0.5 mm.
In this case, the outer diameter of the thin tube is set to 0.8 mm, and the number of the inward projections 54 is set to three. When the outer diameter of the ball 52 is 0.7 mm, the outer diameter of the thin tube is set to 1.0 mm, and the number of the inward protruding portions 54 is set to four.

The pen tip holder 6 is a cylindrical body obtained by injection molding a synthetic resin (eg polypropylene, polyacetal, etc.). The pen tip holder 6 is
It includes a tapered front portion 61 to which the pen tip 5 is attached, a collar portion 62 that comes into contact with the front end surface of the ink containing tube 8, and a rear portion 63 that is press-fitted into the front end opening portion of the ink containing tube 8. Inside the pen tip holder 6, an attachment hole 64 into which the pen tip 5 is press-fitted and fixed, and an ink circulation hole 65 communicating with the rear end of the attachment hole 64 are formed. In addition, the pen tip holder 6
A plurality of axial ribs (not shown) are integrally formed on the outer peripheral surface of the tapered front portion 61, and the ribs are supported by the inner peripheral surface of the tip opening 3.

The ink circulation hole 65 and the chip body 51
A spring 7 including a straight portion 71 and a coil portion 72 is inserted and arranged therein. The straight portion 71 of the spring 7 is inserted into the chip body 51, and the ball 5
2 the front surface of the ball 52 and the front edge 5
3. The inner surface and the inner surface are closely contacted in a ring shape. As a result, when not writing,
The ball 52 is formed by the straight portion 71 of the spring 7.
Is pushed forward, the ball 52 and the tip edge portion 53
The inner surface of the pen is closely contacted, and the pen tip 5 is sealed. As a result, even if the pen tip 5 is stored in a downward state, ink leakage from the pen tip 5 is prevented, and even if the pen tip 5 is stored in an upward state, air mixing from the pen tip 5 is prevented. It

The coil portion 72 of the spring 7
Has a rear end bulged, and the rear end portion of the bulge is locked over the locking projection 66 on the inner surface of the ink circulation hole 65.

The ink containing tube 8 is a cylindrical body having both ends opened, and is obtained by extrusion molding of synthetic resin. A rear portion 63 of a pen tip holder 6 having a pen tip 5 is press-fitted and fixed to a front end opening portion of the ink containing tube 8, while a vent hole is provided through the rear end opening portion of the ink containing tube 8. A tail plug (not shown) is press-fitted and fixed. Inside the ink containing tube 8, ink (for example, a water-based gel ink having a shear thinning property, or an oil ink having a medium viscosity),
A grease-like follower (not shown) disposed at the rear end of the ink and advancing as the ink is consumed is filled. The ink containing tube 8 may be integrally formed with the pen tip holder 6 by injection molding of synthetic resin.

As shown in FIGS. 3 to 5, the tip opening 3
A recess 31 is formed at the open end of the inner peripheral surface of the. The recess 31 is open radially inward and axially forward. An angle α from the center of the tip opening 3 is set to 60 degrees in the circumferential range of the recess 31.

A support portion 33 for supporting the outer peripheral surface of the pen tip holder 6 is formed on the inner peripheral surface of the tip end port 3 excluding the recess 31. The support portion 33 is an annular inner surface formed on the inner peripheral surface of the tip opening 3 behind the recess 31 and the inner peripheral surface of the opening edge of the tip opening 3 excluding the recess 31. It is set to be slightly smaller than the outer diameter of the portion of the pen tip holder 6 that contacts the inner surface of the support portion 33 (that is, the diameter of the rib circumscribing circle).

Further, a gate portion 32 for injection molding is located in the recess 31. In FIGS. 3 and 5, a dot portion indicates a gate mark protruding inward in the radial direction. Since the gate mark slightly protrudes radially inward in the recess 31 and does not protrude inward from the inner peripheral surface of the support portion 33 of the tip end port 3, when the pen tip 5 is retracted, A smooth projecting / retracting operation is maintained without contacting the outer peripheral surface of the holder 6.

[0028]

According to the first aspect of the present invention, the gate mark is not conspicuous, the appearance of the barrel is not impaired, and even if the gate mark is projected, it does not hinder the pen tip retracting operation. The wobble of the pen tip during writing is sufficiently suppressed.

According to the second aspect, even when the support portion supports the outer peripheral surface of the pen tip holder made of synthetic resin, the wobble of the pen tip during writing is sufficiently suppressed.

According to the third aspect, even when the pen tip is a ball-point pen tip having a straight cylindrical thin tube, the wobble of the pen tip during writing is sufficiently prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a pen tip protruding state according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of FIG.

FIG. 3 is an enlarged vertical cross-sectional view of essential parts showing the pen tip sinking state of FIG.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

1 Infestation-type writing instrument Biaxial cylinder 21 Tip 22 Knock part 23 clips 3 Tip mouth 31 recess 32 Gate (gate mark) 33 Support 4 Writing implement refill 5 Nib 51 chip body 52 balls 53 Tip edge 54 Inward protrusion 6 Pen tip holder 61 front 62 collar part 63 rear 64 mounting holes 65 ink circulation hole 66 Locking protrusion 7 spring 71 Straight part 72 coil 8 Ink storage tube 9 coil spring α Angle that represents the range of the concave portion in the circumferential direction

Claims (3)

[Claims] 1. A writing instrument refill is housed inside a shaft cylinder, and a tip opening through which a pen tip of the writing instrument refill can be projected and retracted is provided at a tip end portion of the shaft cylinder. In the retractable writing instrument constituted by, a concave portion is provided in a part of the opening end portion of the inner peripheral surface of the tip opening, and a gate portion for injection molding is provided in the concave portion. A retractable writing instrument characterized in that a support portion for supporting the outer peripheral surface of the writing instrument refill is provided in a portion of the opening end portion excluding the concave portion. 2. The retractable writing instrument according to claim 1, wherein the support portion supports an outer peripheral surface of a pen tip holder made of synthetic resin. 3. The retractable writing instrument according to claim 1, wherein the pen tip is a ball-point pen tip made of a straight cylindrical thin tube.