JP2004034494A - Eraser mounting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eraser mounting structure, with which a plurality of kinds of erasers having outer diameters different from one another can be held. <P>SOLUTION: A mounting hole 2 for mounting an eraser is provided in the main body or the cap 1 of a writing utensil. On the inner surface of the mounting hole 2, a bottom wall 4 and a plurality of ribs 3 extending axially from the bottom wall 4 to an opening side are provided. Each rib comprises a larger diametral part 31 having a larger diametral inscribed circle, a smaller diamtral part 32 being formed behind the larger diametral part 31 and having a smaller diametral inscribed circle and a stepped part 33 formed between the larger diametral part 31 and the smaller diametral part 32. As for an eraser having a comparatively smaller outer diameter, its outside surface is radially brought into pressing contact with the smaller diametral part 33 of the rib 3 of the mounting hole 2 and its rear end is axially abutted against the bottom wall 4 of the mounting hole 2. As for an eraser having a comparatively larger outer diameter, its outside surface is radially brought into pressing contact with the larger diametral part 31 of the rib 3 of the mounting hole 2 and its rear end is axially abutted against the stepped part 33 of the rib 3. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an eraser mounting structure. More specifically, the present invention relates to an eraser mounting structure for pressing an eraser into a mounting hole provided in a writing instrument main body or a cap. In the present invention, “front” indicates the opening side of the mounting hole, and “rear” indicates the opposite side.
[0002]
[Prior art]
Conventionally, Japanese Utility Model Registration No. 2578273 discloses an eraser mounting structure in which a plurality of ribs are provided on the inner surface of a mounting hole and the outer surface of the eraser is pressed and held in the radial direction by the ribs. In this structure, since the inscribed circle diameter of the rib is constant, other erasers having different outer diameters cannot be held. Therefore, if the inscribed circle diameter of the rib is a special size, when replacing the eraser with a new one, a commercially available replacement eraser cannot be attached, which is inconvenient.
[0003]
Conventionally, Japanese Utility Model Registration No. 2577342 discloses that a plurality of projections are provided on the inner surface of a mounting hole, and the plurality of projections include a large projection having a large contact area and a small projection having a small contact area. There is disclosed a structure in which the small projections are installed within the installation range of the large projections and the diameter of the inscribed circle formed by the small projections is smaller than the diameter of the inscribed circle formed by the large projections. This structure is a structure in which even though a plurality of types of rods can be press-fitted and fixed, an eraser having elasticity and a solid correction tool having almost no elasticity can be press-fitted and fixed. It cannot be retained.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide an eraser mounting structure capable of holding a plurality of types of erasers having different outer diameters.
[0005]
[Means for Solving the Problems]
[1] The present invention provides a writing instrument main body or a cap 1 provided with a mounting hole 2 for mounting an eraser, a bottom wall 4 on the inner surface of the mounting hole 2, and a plurality of shafts extending in the axial direction from the bottom wall 4 toward the opening side. An eraser mounting structure for press-fitting an eraser into the mounting hole 2, wherein the rib 3 has a large-diameter portion 31 formed on the opening side of the mounting hole 2 and having a large inscribed circle diameter. A small diameter portion 32 having a smaller inscribed circle diameter formed behind the large diameter portion 31 and a step portion 33 formed between the large diameter portion 31 and the small diameter portion 32 (claim 1). Requirements.
[0006]
According to the eraser mounting structure of the first aspect, the erasers 5.7 having a relatively small outer diameter are radially pressed against the small-diameter portion 32 of the rib 3 of the mounting hole 2 at least on the outer surface thereof. The rear end of the eraser 6 is axially abutted against the bottom wall 4 of the mounting hole 2 and has a relatively large outer diameter. The rear end of the rib 3 is in contact with the step 33 of the rib 3 in the axial direction. That is, it is possible to press-fit and hold a plurality of types of erasers 5, 6, and 7 having different outer diameters in one mounting hole 2.
[0007]
[2] In the eraser mounting structure of the first aspect, it is preferable that the shape of the step portion 33 is an inclined shape whose diameter gradually increases toward the front (claim 2).
[0008]
Since the shape of the step 33 is inclined, the rear ends of the erasers 5 and 7 are not caught on the step 33, and the erasers 5 and 7 can be smoothly pressed into the small diameter portion 32 of the mounting hole 2. it can.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0010]
1 to 3 show a mounting hole 2 of the eraser mounting structure of the present invention. The writing instrument main body or the cap 1 is formed by injection molding of a synthetic resin, and a mounting hole 2 is formed at an end thereof. Specifically, the end of the writing instrument main body or the cap 1 in which the mounting hole 2 is formed is an end opposite to the pen tip side of the writing instrument main body or the pen tip insertion side of the cap. The opposite end.
[0011]
A plurality (specifically, four) of ribs 3 extending in the axial direction are provided at equal intervals on the inner surface of the mounting hole 2. The rib 3 includes a large-diameter portion 31 having a large inscribed circle diameter formed at a front portion, a small-diameter portion 32 formed at a rear portion having a small inscribed circle diameter, and a portion between the large-diameter portion 31 and the small-diameter portion 32. (Ie, a step portion 33 formed at the front end of the small diameter portion 32). The step 33 has an inclined shape whose diameter increases toward the front. The front end of the rib 3 (that is, the front end of the large-diameter portion 31) is formed in an inclined shape such that the diameter of the rib 3 is increased toward the front so that the erasers 5, 6, and 7 can be pressed into each other smoothly. The rear end 3 (that is, the rear end of the small-diameter portion 32) is connected to the bottom wall 4 of the mounting hole 2. The inscribed circle diameter of the rib 3 is the diameter of an imaginary inscribed circle that contacts the vertex of the rib 3. Specifically, the inscribed circle diameter of the large diameter portion 31 is set to 5.8 mm, and the inscribed circle diameter of the small diameter portion 32 is set to 5.05 mm.
[0012]
The cross-sectional shape of the rib 3 of this embodiment is square, but other than this, in order to minimize the frictional resistance with the outer surface of the eraser as much as possible and to easily bite the outer surface of the eraser, The shape may have a pointed inner end (for example, a trapezoid or a triangle).
[0013]
The eraser mounting structure of the present embodiment can hold the following three types of erasers (first eraser 5, second eraser 6, and third eraser 7). The base material of each of the three types of erasers 5, 6, 7 is made of, for example, natural rubber, synthetic rubber, polyvinyl chloride, or various thermoplastic elastomers, and has elasticity.
[0014]
[First eraser]
FIGS. 4 to 6 show a state where the first eraser 5 is press-fitted and held in the mounting hole 2 shown in FIG. The first eraser 5 is cylindrical and has a relatively small outer diameter (specifically, 6.1 mm). That is, the outer diameter of the first eraser 5 is larger than the inscribed circle diameter of the small diameter part 32 and the inscribed circle diameter of the large diameter part 31. The total length in the axial direction of the first eraser 5 is longer than the length in the axial direction from the opening end of the mounting hole 2 to the bottom wall 4.
[0015]
Accordingly, when the first eraser 5 is pressed and held in the mounting hole 2, the rear outer surface thereof is largely deformed radially inward by the small diameter portion 32 of the rib 3 and held in pressure contact, and the front portion thereof is pressed. The outer side surface is deformed small inward in the radial direction by the large diameter portion 31 of the rib 3 and is pressed and held, and further, the rear end thereof is supported by the bottom wall 4 of the mounting hole 2 in the axial direction. The front end of the first eraser 5 that is press-fitted and held protrudes forward from the opening end of the mounting hole 2.
[0016]
[Second eraser]
FIGS. 7 and 8 show a state in which the second eraser 6 is press-fitted and held in the mounting hole 2 shown in FIG. The second eraser 6 is columnar and has a relatively large outer diameter (specifically, 6.8 mm). That is, the outer diameter of the second eraser 6 is larger than the inscribed circle diameter of the large diameter portion 31. The total length in the axial direction of the second eraser 6 is longer than the length in the axial direction from the opening end of the mounting hole 2 to the step portion 33.
[0017]
Thereby, when the second eraser 6 is press-fitted and held in the mounting hole 2, its rear outer surface is deformed radially inward by the large-diameter portion 31 of the rib 3 to be pressed and held, and its rear end is held. , Is axially abutted and supported by an inclined step portion 33 between the large diameter portion 31 and the small diameter portion 32. The front end of the second eraser 6 that has been pressed and held protrudes forward from the opening end of the mounting hole 2.
[0018]
[Third eraser]
FIGS. 9 to 11 show a state in which the third eraser 7 is pressed and held in the mounting hole 2 shown in FIG. The third eraser 7 includes a cylindrical eraser main body 71 and an eraser cover 72 made of a metal cylinder that holds an outer peripheral surface of an intermediate portion of the eraser main body 71. The outer diameter of the eraser cover 72 is set to 5.9 mm, and the outer diameter of the eraser main body 71 projecting forward and rearward from the eraser cover 72 is set to 5.65 mm. That is, the outer diameter of the eraser main body 71 of the third eraser 7 is larger than the inscribed circle diameter of the small diameter portion 32, and the outer diameter of the eraser cover 72 is slightly smaller than the inscribed circle diameter of the large diameter portion 31. Big. The total length in the axial direction of the third eraser 7 is longer than the length in the axial direction from the opening end of the mounting hole 2 to the bottom wall 4.
[0019]
Thus, when the third eraser 7 is pressed and held in the mounting hole 2, the outer surface of the eraser main body 71 projecting rearward from the eraser cover 72 is deformed radially inward by the small-diameter portion 32 and pressed into contact. The eraser main body 71 is held and the rear end thereof is axially abutted and supported by the bottom wall 4 of the mounting hole 2, and the outer surface of the eraser cover 72 is radially pressed and held by the large diameter portion 31. . The front end of the eraser main body 71 of the third eraser 7 pressed and held protrudes forward from the opening end of the mounting hole 2.
[0020]
【The invention's effect】
According to claim 1, a plurality of types of erasers having different outer diameters can be held.
[0021]
According to the second aspect, the eraser can be smoothly pressed into the small-diameter portion of the mounting hole without the rear end of the eraser being caught on the step portion.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a mounting hole according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along line AA of FIG.
FIG. 3 is a sectional view taken along line BB of FIG. 1;
FIG. 4 is a longitudinal sectional view showing a state where a first eraser is press-fitted and held in a mounting hole of FIG. 1;
FIG. 5 is a sectional view taken along line CC of FIG. 4;
FIG. 6 is a sectional view taken along line DD of FIG. 4;
FIG. 7 is a longitudinal sectional view showing a state in which a second eraser is press-fitted and held in the mounting hole of FIG. 1;
FIG. 8 is a sectional view taken along line EE of FIG. 7;
FIG. 9 is a longitudinal sectional view showing a state where a third eraser is press-fitted and held in the mounting hole of FIG. 1;
FIG. 10 is a sectional view taken along line FF of FIG. 9;
FIG. 11 is a sectional view taken along line GG of FIG. 9;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Writing instrument main body or cap 2 Mounting hole 3 Rib 31 Large diameter part 32 Small diameter part 33 Step part 4 Bottom wall 5 First eraser 6 Second eraser 7 Third eraser 71 Eraser main body 72 Eraser cover

Claims (2)

A mounting hole for attaching an eraser is provided in the writing instrument main body or the cap, a bottom wall and a plurality of ribs extending in the axial direction from the bottom wall to the opening side are provided on the inner surface of the mounting hole, and the eraser is provided in the mounting hole. An eraser mounting structure for press-fitting, wherein the rib has a large-diameter portion having a large inscribed circle diameter formed on the opening side of the mounting hole, and a small-diameter portion having a small inscribed circle diameter formed behind the large diameter portion. And an eraser mounting structure comprising a large diameter portion and a step formed between the small diameter portion. The eraser mounting structure according to claim 1, wherein the shape of the step portion is an inclined shape whose diameter gradually increases toward the front.

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