JP2006306082A - Multi-core writing instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that the conventional type of writing instrument with the diameter of its front shaft gradually narrowing down gives an uncomfortable writing feeling to the hand gripping the shaft by the phenomenon that a gap is present between the refill(s) and the inner wall of the shaft and/or between each refill and, allows the refill to move and contact the neighboring refill and to stop there when one refill is being used and tool forced but the neighboring refill, with this impact, then moves alongside the inner wall and makes the refill in use move again and hit the inner wall thus causing a double impact. <P>SOLUTION: The invention relates to the multi-core writing instrument of a construction wherein there is a plurality of writing cores (refills) hung down in the back of the shaft by spring members and pushed out of the shaft body by the forwarding movement of the slide block equipped in the back of the shaft and engaged with the cores in the shaft body. The instrument shaft body is composed of the front shaft and the back shaft and is so designed to have the diameter of circumscribed circle of the plurality of the cores (refills) when one core is pushed out and the inner diameter of the aforementioned shaft body being set to be almost an equal length. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has a plurality of writing bodies in the shaft body, and the writing bodies are urged rearward by an elastic member, and a slider attached to the rear of the writing body is advanced to move the sliders. The present invention relates to a multi-core writing instrument in which the writing body is projected from the shaft body by being engaged in the shaft body, and examples of the writing body include a ball pen refill and a mechanical pencil unit. .

As an example, the operation portions of a plurality of knock members connected to the cursive body are projected into respective longitudinal grooves provided to the rear end portion of the rear shaft, and each knock member is slid toward the shaft tip to selectively write. 2. Description of the Related Art A compound writing instrument is known in which a portion is projected and locked from a tip hole of a front shaft. A slit portion communicating with the longitudinal groove and slidably guiding the knock member is formed on the rear shaft so as to open to the front end of the rear shaft. In addition, an engagement protrusion is formed on the outer periphery of the front end of the rear shaft, and the engagement protrusion is locked to an engagement step provided in the inner hole of the middle shaft by elastic deformation on the reduced diameter side of the rear shaft tip. The rear shaft is fixed in a state of being fitted to the middle shaft.
On the other hand, the diameter of the tip shaft screwed to the tip of the middle shaft gradually decreases toward the tip. Of course, the shape of the inner surface is gradually reduced, resulting in a conical inner surface. Further, a gap, that is, a space is formed between a plurality of adjacent writing bodies provided in the shaft, and a space is also formed between the inner surfaces of the shaft.

Japanese Patent Laid-Open No. 2001-150871.

  In the structure in which the inner diameter of the front shaft gradually decreases in the tip direction as in the prior art, there is a space between the inner surface of the shaft and the cursive body, and between adjacent cursive bodies (see FIG. 15). When writing pressure is applied to the writing body that is in a writing state in a protruding state, the curvature located inside the axis of the writing body in the writing state increases and contacts another writing body that is in an immersive state (see FIG. 16). By this contact, the first impact is transmitted to the gripping finger. When the writing pressure is further increased, the curving of the writing body in the writing state increases, the other writing body in the contact state is moved, and the contact is released along with the movement, and the writing state is moved with the release. The cursive body located on the surface collides with the inner surface of the shaft (see FIG. 17). This collision is the second impact. In this way, depending on the writing pressure, it was subjected to a two-stage impact, and the writing feeling was significantly impaired.

  The present invention has a plurality of writing bodies in the shaft body, and the writing bodies are urged rearward by an elastic member, and a slider attached to the rear of the writing body is advanced to move the sliders. In the multi-core writing instrument which is made to project the writing body from the shaft body by being engaged in the shaft body, the shaft body is composed of a front shaft and a rear shaft, and the one writing body projects. The gist is that the circumscribed circle diameter of the plurality of writing bodies and the inner diameter of the shaft body are substantially the same.

  The present invention has a plurality of writing bodies in the shaft body, and the writing bodies are urged rearward by an elastic member, and a slider attached to the rear of the writing body is advanced to move the sliders. In the multi-core writing instrument which is made to project the writing body from the shaft body by being engaged in the shaft body, the shaft body is composed of a front shaft and a rear shaft, and the one writing body projects. Since the circumscribed circle diameter of the plurality of writing bodies and the inner diameter of the shaft body are almost the same, the impact of the writing body due to excessive writing pressure can be prevented as much as possible, and as a result, a good writing feeling can be obtained. can get.

This will be described with reference to FIGS. This is a multi-core writing instrument in which ballpoint pens of three colors, black, red and blue, are slidably arranged. You may combine not only a ball-point pen but a mechanical pencil suitably. Reference numeral 1 denotes a shaft main body, and the shaft main body 1 includes a front shaft 2 and a rear shaft 3. Further, in this example, the front shaft 2 is constituted by a screwed structure of the tip member 4 and the middle shaft 5, but may be formed integrally.
The rear shaft 3 is formed with three slits 6 in the longitudinal direction. In this example, three slits 6 are formed, but the number of ball-point pens that are cursive letters is three, and the number of slits that are formed varies depending on the number of cursive letters. The slit 6 is formed up to one end of the rear shaft 3, and sliding grooves 7 are formed on both sides of the slit 6. However, the sliding groove 7 is not formed over the entire length of both sides of the slit 6 but is formed only up to the middle portion.
A substantially fan-shaped leg portion 8 whose cross-sectional shape expands in the outer diameter direction is formed in front of the rear shaft 3. The leg portion 8 is formed by forming the slit 6. Therefore, the number of legs 8 varies depending on the number of cursive letters. The circumscribed circle diameter of the leg portion 8 is formed smaller than the maximum outer diameter of the rear shaft 3. In other words, a stepped portion (saddle portion) 3 b is formed at a connecting portion between the maximum outer diameter portion of the rear shaft 3 and the leg portion 8. Further, the leg portion 8 of the rear shaft 3 is formed with a protruding rib 8 a that contacts the inner wall of the middle shaft 5. Further, a protruding rib 5a is also formed on the rear end surface of the intermediate shaft 5, but this rib 5a is not formed over the entire periphery of the rear end surface of the intermediate shaft 5, but is formed partially. ing. Specifically, it is formed at four equally spaced locations. Further, in this example, the rib 5a is formed on the extension of the inner peripheral surface of the middle shaft 5. However, the rib 5a is not limited to this, and the rib 5a is formed with the step portion (bump portion) 3b of the rear shaft 3. It may be formed at any position on the rear end surface of the middle shaft 5 as long as it is in contact. The ribs 8a of the leg portions 8 and the ribs 5a of the central shaft 5 are melting portions for welding and fixing described later. That is, the rib 8a of the leg portion 8 is in contact with the inner surface of the middle shaft 5 and is welded and fixed, and the rib 5a of the middle shaft 5 is in contact with the lower end of the flange portion 3a and is welded and fixed.

  A slider 11 is slidably disposed in the slit 6 of the rear shaft 3. Sliding projections 12 are formed on both sides of the slider 11 in the longitudinal direction, and are slidably engaged with the sliding grooves 7 formed in the slit 6. Two release protrusions 13 and 14 are formed on the back surface of the slider 11 at intervals, and a spherical connection portion 15 for connecting the cursive body is formed on the front end portion of the slider 11. The connecting portion 15 is connected to a writing body 16 such as a ballpoint pen or a mechanical pencil. Reference numeral 17 is an elastic member such as a coil spring that biases the writing body 16 and the slider 11 connected to the writing body 16 backward.

A restricting portion 18 is formed in an intermediate portion of the middle shaft 5 that is one member of the front shaft 2, and three through holes 19 into which the writing body 16 is loosely inserted are formed in the restricting portion 18. The cursive body 16 is urged rearward by locking one end of the elastic member 17 to the restricting portion 18. In addition, three grooves 20 are formed in the longitudinal direction inside the middle shaft 5 and behind the restricting portion 18, and the legs 8 of the rear shaft 3 are slidably contacted with the grooves 20. 8 is guided. Further, the groove portion 20 has substantially the same shape as the cross-sectional shape of the leg portion 8. That is, a fan shape that expands in the outer diameter direction is formed.
Further, the groove 20 is formed with a rib 20a that has a height that does not contact the leg 8 of the rear shaft 3 and is smaller than the circumscribed diameter of the rib 8a formed on the leg 8 of the rear shaft 3. . The rib 20a formed in the groove portion 20 is for preventing the rear shaft 3 from easily coming off from the middle shaft 5 until the rear shaft 3 and the middle shaft 5 are welded and fixed at the time of assembly.
Also, the rear shaft 3 and the middle shaft 5 are not fixed by ultrasonic welding, but are substantially square on the same straight line as the groove 20 described later between the three grooves 20 and in the vicinity of the outer edge of the restricting portion 18. A connecting portion of a large diameter portion 8b and a small diameter portion 8c formed on the leg portion 8 of the rear shaft 3 on a protrusion 21 formed above the through hole 19a in which a through hole 19a having a shape is formed. A concave engaging portion 3a provided on the inner shaft 5 may be engaged (see FIGS. 7 and 8), and the fixing method of the middle shaft 5 and the rear shaft 3 is not limited to the above-described means. Further, the rear shaft 3 and the middle shaft 5 may be integrally formed.

Next, the effect | action by ultrasonic welding is demonstrated. After the leg portion 8 of the rear shaft 3 is inserted into the groove portion 20 of the middle shaft 5 and the flange portion 3b is brought into contact with the rib 5a of the middle shaft 5, the horn (H) of the ultrasonic welder is moved to the rear of the rear shaft 3. Abut on the end face. Due to the vibration generated from the horn (H), the welding rib 5a on the rear end surface of the middle shaft 5 is first melted, and welding with the rear shaft 3 is started. Next, the vibration of the horn (H) is transmitted to the leg portion 8 of the rear shaft 3, the rib 8a of the leg portion 8 in contact with the inner surface of the middle shaft 5 is melted, and welding with the inner surface of the middle shaft 5 is started. . That is, the middle shaft 5 and the rear shaft 3 are welded and fixed at two locations, that is, the rear end surface portion of the middle shaft 5 and the leg portion 8 of the rear shaft 3. At this time, the rib 20a formed in the groove portion 20 of the middle shaft 5 is not in contact with the leg portion 8 of the rear shaft 3, so that it is not melted by vibration, and vibration from the horn (H) is absorbed by the rib 20a. Therefore, the vibration of the horn (H) can be efficiently transmitted to the rib 8a provided on the leg portion 8 of the rear shaft 3.
Further, in this example, a retractable compound writing instrument in which a slider 11 is slidably arranged in the slit 6 of the rear shaft 3 is used. However, the slit 6 is not a slider 11 but a design component such as a doll, for example. May be fixed. Reference numeral H denotes a grip provided at a gripping portion. In this example, an elastic member made of silicone rubber or elastomer is inserted in the middle portion of the tip member 4, but rubber-like paint, foam paint, etc. May be applied, or the surface of the tip member 4 may be imparted with anti-slip properties by applying a fine knurling process or a satin finishing process.

A tip member 4 as one member of the front shaft 2 is detachably fixed to the middle shaft 5 by screwing. The tip member 4 and the center shaft 5 may be integrally formed. However, considering the ease of replacement of the writing body 16 and molding, it is better to use two members and fix them detachably.
In addition, the inner diameter portion of the tip member 4 gradually decreases in diameter toward the pen tip side and has a conical inner shape portion. A small diameter portion 10 that is biased toward the central axis of the shaft main body 1 is formed integrally with the tip member 4. The small diameter portion 10 may be formed by a plurality of ribs 22.
The shape of the small-diameter portion 10 is formed on the entire circumference over almost the entire area in front of the inner diameter portion of the tip member 4, but the width in the longitudinal direction (longitudinal direction of the shaft) may be reduced. The small-diameter portion 10 may be formed as a separate ring-shaped component and inserted and fixed to the tip member 4. That is, it may be a band-shaped small diameter portion. However, the present invention is not limited to the band-shaped small-diameter portion, and a cut may be formed partially, or a plurality of narrow circumferential-band small-diameter portions having a narrow width may be formed in the longitudinal direction of the front shaft 3. .
Incidentally, by forming a cut in the band-shaped small-diameter portion 10, sink marks and the like during injection molding are prevented from the relationship with the thickness of the tip member 4. From the viewpoint of preventing this shrinkage, the small diameter portion 10 may be formed as a plurality of vertical ribs on the inner diameter portion of the tip member 4. At this time, the interval between adjacent ribs is preferably smaller than the outer diameter of the cursive body 16 so that the cursive body 16 to be accommodated is not completely fitted between the ribs. Furthermore, the cross-sectional shape of the rib may be appropriate as long as the cursive body 16 to be accommodated is urged toward the center line of the shaft body 1. Further, the shape of the rib in the longitudinal direction is preferably at a position where the space in which the writing body 16 in the writing state is curved in the tip member 4 is minimized. More specifically, the cross-sectional shape of the rib 22 is a trapezoidal shape, but an arc-shaped chamfering process is applied to the corner portion. In addition, an inclined surface 22 a that descends toward the center direction is also formed at the rear end portion in the longitudinal direction of the rib 22. By forming the inclined surface 22 a, the inclined surface 22 a serves as a guide that allows the writing body 16 to be smoothly accommodated in a predetermined position of the tip member 4 during assembly or when the writing body 16 is replaced. (See FIGS. 9 to 11).

In the band-shaped small-diameter portion, since the small-diameter portion exists over the entire circumference of the inner diameter portion of the tip member 4, even if the writing body 16 itself is deformed (bent), the writing body 16 is pivoted. The main body 1 can be biased toward the central axis. Moreover, in the small diameter part in which the notch is formed, sink marks and the like in the case where the resin material is molded as described above can be prevented. In addition to this, when the small-diameter portion is constituted by vertical ribs, the above-described sink marks and the like are prevented, and even when the writing body 16 itself is deformed and the outer diameter of a part thereof is increased, Since the other writing body 16 can be pushed and moved between the adjacent vertical ribs, as a result, the sliding of the writing body 16 is smoothly prevented without being disturbed.
Further, a ratio of a part of the inscribed circle diameter A of the small diameter portion 10 of the tip member 4 to the circumscribed circle diameter B (see FIG. 14) of the cursive body 16 accommodated is A / B = 1.0 to If it is set to 1.3, a favorable front shaft will be obtained for the slidability of the writing body 16 and the writing feeling during writing.
In addition, when the ratio A / B of the inscribed circle diameter of the small diameter portion 10 of the tip member 4 is less than 1.0, a space formed between a plurality of adjacent writing bodies 16 or an inner surface of the shaft Since the space formed between them can be reduced, the curvature located inside the tip member 14 of the writing body 16 in the writing state can also be reduced, but it rubs against the adjacent writing body 16 when sliding. This will impair the sliding feeling.
Further, when the ratio A / B of the inscribed circle diameter of the small diameter portion 10 of the tip member 4 exceeds 1.3, a space formed between a plurality of adjacent writing bodies 16 installed, The space formed between the inner surfaces of the shaft is also increased, and the curvature located inside the tip member 14 of the writing body 16 in the writing state is also increased, which collides with the inner surface of the tip member 4 caused by the increased writing pressure. The impact will increase and the writing feeling will be greatly impaired.
That is, a part of the inscribed circle diameter A of the small diameter portion 10 of the tip member 4 is closely related to the inscribed circle diameter B of the inscribed writing body 16, and the relationship is expressed as A / B = 1.0˜ By setting it as 1.3, the writing instrument which does not impair the above-mentioned sliding feeling and writing feeling can be obtained.
In this example, the diameter of the outer diameter of the writing body 16 is 2.65 mm (the diameter of the outer diameter A of the writing body 16 in the shaft is 5.7 mm), and the inscribed circle diameter B of the small diameter portion of the tip member 4 is It consists of eight ribs with a minimum diameter of 6.17 mm and a maximum diameter of 6.57 mm.

Next, the operation will be described. When a specific slider 11 is pressed forward (downward in the figure) from the state shown in FIG. 1 (FIG. 12), the slider 11 moves forward with the writing body 16 while being guided by the slit 6 and the sliding groove 7. The tip of the body 16 protrudes from the tip of the shaft body 1. At the same time, the slider 11 is pushed into the inner side of the barrel body 1, and then the rear end of the sliding protrusion 12 formed on the side surface of the slider 11 is engaged with the front end of the sliding groove 7, The backward action of the cursive body 16 is prevented. That is, by forming the sliding groove 7 only up to the middle part of the slit 6, the slider 11 is also engaged.
In the projecting process of the writing body 16, the writing body 16 is urged toward the central axis of the shaft body 1 by the small diameter portion 10, and the writing body 16 moves toward the center of the shaft body 1 by the urging. To do. As a result, the protruding cursive body comes into contact with another cursive body that is immersed. Therefore, when the cursive body in the protruding state is moved by the pen pressure, it moves with the other cursive body in the immersive state (see FIGS. 13 and 14), and the writing as shown in the prior art. The body does not collide, and good writing is obtained. In addition, the arrow shown by FIG. 13, FIG. 14 is the direction of the force generate | occur | produced in a cursive body by writing pressure.
Further, when the shape of the small-diameter portion 10 is the vertical rib 22, the writing body 16 is urged toward the central axis of the shaft body 1 by the rib 22 during the protruding process of the writing body 16 as described above. The cursive body 16 moves toward the center of the shaft body 1 by the biasing. As a result, at the same time that the protruding cursive body comes into contact with the other cursive body, the other cursive body 16 falls between the two adjacent vertical ribs 22 and a part of the cursive body 16 falls into the ribs. It will be fixed between. Therefore, when the writing body in the protruding state with the writing pressure tries to move, the other writing body in the immersive state is fixed between the adjacent ribs in the tip member 4, so as shown in the prior art The cursive action between the cursives does not occur, and good writing is obtained.
Next, when the writing body 16 is to be stored in the shaft body 1, the other slider 11 is pressed. When the other slider 11 is pressed, the release protrusions 13 and 14 formed on the back surfaces of the sliders 11 collide with each other. By this collision action, the slider 11 in the pressed state is pressed in the outer direction of the shaft cylinder main body 1. Then, by this pressing action, the engagement between the sliding projection 12 and the sliding groove 7 of the slider 11 is released, and the writing body 16 which is in the protruding state by the releasing action is retracted by the action of the elastic member 17. The shaft body 1 is immersed.

The longitudinal cross-sectional view which shows one example of this invention. The longitudinal cross-sectional view of the writing state which shows an example of this invention. The principal part enlarged view which shows the ultrasonic welding method. The EE sectional view taken on the line of FIG. The CC sectional view taken on the line of FIG. The DD sectional view taken on the line of FIG. The longitudinal cross-sectional view which shows the fixing method of the other rear axis | shaft and middle axis | shaft which shows an example of this invention. GG sectional view taken on the line of FIG. The longitudinal cross-sectional view of the tip member which shows one example of this invention. FF sectional view taken on the line of FIG. Sectional drawing which shows the FF line sectional drawing of FIG. 9 which shows the inscribed circle diameter of a tip member, and the circumscribed circle diameter of a cursive body. AA sectional view taken on the line AA of FIG. BB sectional drawing of FIG. Sectional drawing equivalent to the BB line of FIG. 2 which shows the movement operation | movement of a cursive body. Sectional drawing equivalent to the AA line of FIG. 1 which shows the nib accommodation state of a prior art. Sectional drawing equivalent to the BB line of FIG. 2 which shows the writing state of a prior art. Sectional drawing equivalent to the BB line of FIG. 2 which shows the movement operation | movement of the cursive body of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft body 2 Front shaft 3 Rear shaft 3a Engagement part 3b Step part (hook part)
4 Tip member 5 Center shaft 5a Rib (welding rib)
6 Slit 7 Sliding groove 8 Leg 8a Rib 8b Large diameter 8c Small diameter 9 Clip part 10 Small diameter 11 Slider 12 Sliding projection 13 Release projection 14 Release projection 15 Connection unit 16 Writing body 16a Cursive body (writing state)
17 Repellent member 18 Restriction part 19 Through hole 19a Through hole 20 Groove part 20a Rib 21 Protrusion 22 Rib 22a Inclined surface 23 Inscribed circle diameter 24 circumscribed circle diameter

Claims (6)

The shaft body has a plurality of writing bodies, and the writing bodies are urged backward by the elastic member, but the slider attached to the back of the writing body is advanced, and the slider is moved into the shaft body. In the multi-core writing instrument in which the writing body is projected from the shaft body by being engaged, the shaft body is composed of a front shaft and a rear shaft, and a plurality of the writing bodies are projected when the one writing body protrudes. A multi-core writing instrument, wherein the circumscribed circle diameter of the writing body and the inner diameter of the shaft body are substantially the same. A small-diameter portion is formed in the inner diameter portion of the front shaft, and the inner diameter of the small-diameter portion is substantially the same as the circumscribed circle diameter of the plurality of writing bodies when the one writing body protrudes. The multi-core writing instrument according to 1. The multi-core writing instrument according to claim 2, wherein the small-diameter portion is formed of several ribs. The ratio (A / B) between the inner diameter of the front shaft or the inner diameter (A) of the small diameter portion and the circumscribed circle diameter (B) of the plurality of writing bodies when the one writing body protrudes is 1.0. The multi-core writing instrument according to any one of claims 1 to 3, wherein the multi-core writing instrument is in a range of ~ 1.3. The multi-core writing instrument according to any one of claims 1 to 4, wherein the small-diameter portion is formed integrally with a front shaft. The multi-core writing instrument according to any one of claims 1 to 4, wherein the small-diameter portion is formed as a separate part and fixed in the front shaft.

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