JP2020082638A - Retractable multi-core writing instrument - Google Patents

Abstract

To provide a retractable writing instrument in which an axis of a core body either deployed or retracted during use and an axis of a cylinder body can be aligned to simply prevent an erratic state in positioning of the axis of the core body caused by eccentricity between the axes, without disturbing smooth operation, and which is easy to grasp.SOLUTION: A retractable multi-core writing instrument comprises: a cylinder body containing a plurality of core bodies made of an elastic material therein; and a mechanism for deploying/retracting a selected one of the core bodies from/into the cylinder body. A protrusion is provided on an outer peripheral surface of the core body so as to protrude toward an inner peripheral surface of the cylinder body. In a grip of the cylinder body, an upper portion of the grip is thicker than a lower portion of the grip, and an inner diameter is gradually reduced as proceeding from the upper portion of the grip to the lower portion of the grip. The protrusion contacts an inner peripheral surface of the upper portion of the grip when the core is retracted, and contacts an inner peripheral surface of the lower portion of the grip when used.SELECTED DRAWING: Figure 3

Description

The present invention is a retractable multi-core writing instrument having a mechanism for retracting one core body selected at the time of use from a tubular body, and more specifically, the axis line of the retracted core body coincides with the axis line of the tubular body. Thus, the present invention relates to a configuration of a retractable multi-core writing instrument that prevents shaft runout due to eccentricity.

The conventional retractable multi-core writing instrument has a structure in which a plurality of core bodies are eccentrically housed in the cylinder body, and when one core body is retracted from the cylinder body during use, as shown in FIG. The core body of the elastic material is curved in an arcuate shape in the cylinder body, and as a result, as shown in FIG. Did not match. As a result, the stability during use deteriorates, and the writing angle between the paper surface and the tip of the core body becomes 60 degrees or less, and paper rubbing due to caulking occurs, and smooth writing comfort cannot be obtained. Further, when such a writing instrument is used for a long time, there is a problem that fatigue easily accumulates.

As a solution to this problem, Patent Document 1 discloses a multi-core writing instrument in which a chuck member for gripping the core is arranged near the opening where the core is exposed to the outside.

However, since this multi-core writing instrument has many members and has a complicated structure, the number of manufacturing steps is increased and the cost is increased in implementation, so that it can be used for an off-the-shelf ballpoint pen or the like. Was not.

Therefore, in order to solve such a problem, the applicant has provided a convex portion on each of the inner peripheral surface of the cylindrical body and the outer peripheral surface of the core body of the writing instrument, and the core convex portion abuts on the cylindrical convex portion to form the core. A retractable multi-core writing has been developed which is characterized in that the core is elastically deformed so that the body tip side and the axis of the cylinder coincide with each other (Patent Document 2).

This product has convex parts on the inner peripheral surface of the cylinder and the outer peripheral surface of the core, and when these convex parts come into contact with each other during use, the core elastically deforms and the axis of the cylinder It agrees with. As a result, shaft runout due to eccentricity can be prevented, and smooth and stable writing comfort can be obtained.

However, in spite of such effects, the present invention has the following problems. That is, this product has convex portions on the inner peripheral surface of the cylindrical body and the outer peripheral surface of the core body, and when both convex portions are in contact with each other during use, the core body elastically deforms, and the axis of the core body is changed. Although it coincides with the axis of the cylindrical body, the contact area between the both convex portions is small, and even if the position of the core body is displaced in the vertical direction even by a slight amount, the desired effect could not be obtained.

Further, when the core convex portion and the cylindrical convex portion are in contact with each other, the resistance between the convex portions is greatly caught, which hinders a smooth operation at the time of retracting the core.

Further, when the inner peripheral surface of the tubular body and the outer peripheral surface of the core body are each provided with a convex portion, the tubular body may become thicker than the conventional one, which may impair ease of gripping.

JP-A-9-66696 Utility model registration No. 3123587

Therefore, the present invention overcomes such drawbacks of the conventional retractable multi-core writing instrument, aligns the axis of the core and the cylinder during use, and can easily prevent shaft runout due to eccentricity and smooth It is an object of the present invention to provide a retractable writing instrument that is easy to grasp without hindering the retracting operation of the core body.

The present invention is to solve the above-mentioned problems, and is a retractable type multi-device equipped with a tubular body accommodating a plurality of cores made of an elastic material, and a mechanism for retracting one selected core from the tubular body. A lead writing instrument, wherein the outer peripheral surface of the core body is provided with a protrusion projecting toward the inner peripheral surface of the tubular body, and in the grip portion of the tubular body, the upper grip portion is thicker than the lower grip portion, and The inner diameter of the grip part is gradually reduced from the upper part of the grip part to the lower part of the grip part.The protrusion contacts the inner peripheral surface of the upper part of the grip part when the core body is housed, and the inner circumference of the lower part of the grip part when used. A retractable multi-core writing instrument characterized in that it comes into contact with a surface.

In the retractable multi-core writing instrument according to the present invention, the core body is elastically deformed by the protrusion that abuts on the inner peripheral surface of the lower portion of the grip portion, and the axes of the core body and the cylinder coincide with each other. Further, since the inner diameter of the middle part of the grip part gradually decreases from the upper part of the grip part to the lower part of the grip part, the projection part moves smoothly while contacting these inner peripheral surfaces, and the core body appears and disappears. The operation can be performed smoothly without getting caught.

In addition, since the protrusion of the core body only needs to contact with any part of the inner peripheral surface of the lower part of the grip during use, it should be used without being affected by the vertical displacement of the core body. You can

Further, since the retractable multi-core writing instrument according to the present invention is formed so as to become gradually thinner from the upper part of the grip part to the lower part of the grip part, it has a feature that it is easy to grip.

The front view of the retractable multi-core writing instrument of the present invention. (A) The top view of the core of the retractable multi-core writing instrument of this invention, (b) The front view. FIG. 3 is a vertical cross-sectional view of a grip portion of the retractable multi-core writing instrument of the present invention. (A) The cross-sectional view of the grip part of this invention, (b) The cross-sectional view of the grip part of another embodiment of this invention. (A) A cross-sectional view of a conventional retractable multi-core writing instrument (the internal spring is omitted), (b) An enlarged cross-sectional view near the tip of the conventional retractable multi-core writing instrument.

Hereinafter, embodiments of the retractable multi-core writing instrument of the present invention will be specifically described with reference to the drawings. The present invention is not limited to these embodiments.

FIG. 1 is a front view showing a retractable multi-core writing instrument according to the present invention. The retractable multi-core writing instrument according to the present invention accommodates a plurality of core bodies 2 formed of an elastic material inside a cylindrical body 1 serving as a main body. The user uses one core body 2 arbitrarily selected from the core bodies 2 by protruding and retracting from the cylinder body 1. A mechanism for retracting the core body 2 from the cylinder body 1 is a known mechanism called a so-called knock type, and the knock member 15 connected to the rear end of the selected core body 2 is pushed down toward the tip end of the cylinder body 1. By doing so, it is projected and retracted from the tip opening portion 14. The material of the core body 2 is not particularly limited as long as it is an elastic material that is appropriately bent when the core body 2 is laterally pressed, in addition to commonly used polypropylene and the like.

The tubular body 1 includes a tubular body upper portion 11, a grip portion 12 detachably attached to a lower end of the tubular body upper portion 11, and a tip portion 13 connected from the lower end of the grip portion 12. The upper part 11 of the cylinder and the grip 12 may be attached by attaching screw parts to the outer peripheral surface of the upper part 11 of the cylinder and the inner peripheral surface of the grip part 12 and screwing them together. It is preferable to use external fitting press-fitting, which does not require coupling.

As shown in the figure, the grip 12 has different thicknesses at the upper part and the lower part. That is, the upper grip portion 121 is formed to be thicker than the lower grip portion 123, and the thickness of the middle grip portion 122 is gradually reduced from the upper grip portion 121 to the lower grip portion 123. It is formed so that it becomes thinner. That is, from the upper grip portion 121 to the lower grip portion 123, the inner diameter of the middle grip portion 122 is gradually reduced. The grip portion 12 may cover the outer peripheral surface with a slip stopper formed of an elastic material such as rubber.

As shown in FIG. 2, the core body 2 housed inside the cylinder body 1 is provided with a protrusion 21 projecting toward the inner peripheral surface of the cylinder body 1 on the outer peripheral surface thereof. The protrusion 21 of the present embodiment is formed in a substantially rectangular shape with a rounded tip, but the shape of the protrusion 21 is not limited to this, and may be a semicircle, a semi-oval, a trapezoid, a square, a rectangle, or the like. It may have a shape.

The protruding height of the protrusion 21 is formed so as to be substantially equal to the distance from the outer peripheral surface of the core body 2 to the inner peripheral surface of the opposing cylinder body 1 when the protrusion portion 21 is stored. The axial length of the protrusion 21 in the core body 2 is preferably set to a length that does not hinder the elastic deformation of the core body 2, and is particularly preferably about 3 to 5 mm. A material different from that of the core body 2 may be selected for the protruding portion 21, and after the core body 2 is formed, it may be separately adhesively molded, but it is easier to manufacture and obtain strength by selecting the same material and integrally molding. It is also preferable from the point of view.

Further, when the core body 2 rotates about its axis during use, the protrusion 21 thereof does not properly contact the inner peripheral surface of the grip portion 12. In order to prevent such shaft rotation, a shaft rotation preventing means for the core body 2 may be provided at the joint between the knock member 15 and the core body 2. Specifically, as shown in FIG. 2A, the opening shape near the upper end of the core body 2 to which the knock member 15 is joined is made into a quadrangle, and the end of the knock member 15 inserted into the hole 22 is also made. By making the cross-sectional shape a quadrangle, it is possible to prevent axial rotation of the core body 2. The shape of the opening of the hole 22 and the shape of the end of the knock member 15 are not limited to a quadrangle, and may have an uneven portion that fits with each other.

Further, as another means for preventing shaft rotation of the core body 2, a groove for guiding the movement of the protrusion 21 may be formed on the inner peripheral surface of the grip 12. The groove is a vertical groove formed along the position where the protrusion 21 abuts, and is formed in a concave shape into which the tip of the protrusion can be inserted. By inserting the tip of the protrusion 21 into the groove, it is possible to effectively prevent the axial rotation of the core 2 during the operation of retracting the core 2.

With reference to FIG. 3, the positional relationship of the protrusions 21 when the core body 2 is stored and used will be described in more detail. The core body 2 represented by the solid line on the rightmost side in the figure shows the position of the core body 2 during storage. Thus, at the time of storage, the tip end of the protrusion 21 is inside the upper grip portion 121. It touches the surface. In the present embodiment, the tip of the protrusion 21 is in contact with the inner peripheral surface of the upper grip portion 121 even during storage, but is not always in contact with the inner peripheral surface of the upper grip portion 121 during storage. You may.

Then, when the user pushes down the knock member 15 toward the tip end of the cylinder 1 to move the core 2 in order to allow the core 2 to emerge from the cylinder 1, the protrusion 21 also moves downward accordingly. To do. The protrusion 21 moves downward while contacting the inner peripheral surface of the grip intermediate portion 122 formed so as to gradually reduce in diameter to the grip lower portion 123, and at that time, the inner peripheral surface of the grip intermediate portion 122 is It is pushed by and moves in the axial direction.

When the core body 2 emerges from the tubular body 1 and is ready for use, the tip end of the protrusion 21 comes into contact with the inner peripheral surface of the lower grip portion 123 and stops. The core body 2 made of an elastic material is pushed toward the center of the cylindrical body 1 by the protrusion 21 that abuts on the inner peripheral surface of the lower grip portion 123, and elastically deforms. Since it fits into the tip opening 14 in a substantially vertical state, the axes of the core body 2 and the cylinder body 1 are aligned below the protrusion 21.

Further, the positional relationship of the core body 2 during storage and use will be described with reference to FIG. In these examples, among the three core bodies 2 stored, the core body 2 shown in the upper center of the figure is selected and used. For easier understanding, the cross sections of the upper grip portion 121 and the lower grip portion 123 are shown in the same drawing. As shown in FIG. 4( a ), the core body 2 is located in the solid line portion during storage, but the center of the core body 2 is located at the center of the tubular body 1 as the core body 2 and the protrusion 21 move downward. It slides in the axial direction, is finally located in the broken line portion, and coincides with the axial line of the tubular body 1.

In the mode of FIG. 4A, the upper grip portion 121 and the lower grip portion 123 are both formed to have a circular cross-sectional shape, but the cross-sectional shapes may be different, for example, FIG. As shown in (b), the upper grip portion 121 may be formed in a circular shape, and the lower grip portion 123 may be formed in a rice ball shape. In this way, by making the grip lower part 123 into a diaper shape, it is easy to grip and the tip of the protrusion 21 comes into contact with the corner portion of the diaper shape which is always applied. Can be prevented.

Further, a packing part 16 as shown in FIG. 3 may be provided in the middle of the grip lower part 123. The packing part 16 is a ring-shaped member made of an elastic material such as rubber, and the lower grip part 123 is divided into upper and lower parts with the packing part 16 as a boundary. By providing such a packing portion 16, the grip portion 12 has an effect of flexing at the time of use, and the writing comfort is further improved. The packing portion 16 may be provided alone in the lower grip portion 123 as in the embodiment of FIG. 3, but when the entire grip portion 12 is covered with a slip stopper formed of an elastic material, such a slip stopper is provided. It may be fixed to the inner peripheral surface of or may be integrally formed with a slip stopper.

According to the retractable multi-core writing instrument of the present invention, when the core body 2 is retracted, the protrusion 21 moves while contacting the inner peripheral surface of the upper grip portion 121 or the lower grip portion 123, but from the upper grip portion 121 to the grip portion. Since the grip portion middle portion 122 is formed so as to gradually decrease in diameter toward the lower portion 123, the protrusion 21 can move smoothly without receiving a large sliding resistance. Further, since the protrusion 21 has only to come into contact with any of the inner peripheral surfaces of the lower grip portion 123, the vertical position shift of the core body 2 does not influence.

Although the number of the core bodies 2 is three in the present embodiment, the number of the core bodies 2 is not limited to this, and may be two or four or more. Further, all of the core bodies 2 may be core bodies of a ball-point pen that contains ink, or one of them may be a core body that houses the core of a mechanical pencil. In the case of a core body that accommodates the core of a mechanical pencil, the core of the mechanical pencil is appropriately elastically deformed as the elasticity of the core body 2 is changed, so that it does not break inside.

In the retractable multi-core writing instrument of the present invention, the grip upper part 121 is thicker than the grip lower part 123, and the thickness of the grip middle part 122 gradually increases from the grip upper part 121 to the grip lower part 123. Since it is formed so as to become thinner, when the grip portion 12 is gripped, the forefinger and the thumb are hooked on the grip portion middle portion 122, and it is easy to grip.

1 ……… Cylindrical body 2 ……… Core body 11 ……… Cylindrical body upper part 12 ……… Grip part 13 ……… Mouth part 14 ……… Tip opening part 15 ……… Knock part 16 ……… Packing part 21 ……… Projection part 22 ……… Core body upper end opening 121 ……… Grip upper part 122 ……… Grip middle part 123 ……… Grip lower part X ……… Cylindrical body axis Y ……… Core body axis

Claims (6)

What is claimed is: 1. A retractable multi-core writing instrument comprising: a cylindrical body having a plurality of elastic cores housed therein; and a mechanism for retracting and selecting one selected core from the cylindrical body. Is provided with a protrusion projecting toward the inner peripheral surface of the tubular body, and in the grip portion of the tubular body, the upper grip portion is thicker than the lower grip portion, and the inner diameter gradually increases from the upper grip portion to the lower grip portion. The projecting portion is formed so as to be reduced in diameter, and the protrusion contacts the inner peripheral surface of the upper part of the grip when the core is stored, and contacts the inner peripheral surface of the lower part of the grip when in use. Writing instrument. The retractable multi-core writing instrument according to claim 1, characterized in that a shaft rotation preventing means of the core body is provided at a joint portion between the knock member and the core body. The retractable multi-core writing instrument according to claim 1 or 2, wherein a groove for guiding the movement of the protrusion is provided on the inner peripheral surface of the grip. 4. The retractable multi-core writing instrument according to claim 1, wherein the upper part of the grip part and the lower part of the grip part are formed such that their cross-sectional shapes are different from each other. 5. The retractable multi-core writing instrument according to claim 4, wherein the upper part of the grip part has a circular shape, and the lower part of the grip part has a rice ball-shaped cross-sectional shape. The retractable multi-core writing instrument according to any one of claims 1 to 5, wherein a packing part for dividing the lower part of the grip part into upper and lower parts is provided in the middle of the lower part of the grip part.

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