JPH09263087A - Cap backward insertion fitting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain appropriate fitting force for a long period of time by a method wherein spreading deformation of a fitting part of an inner cylinder is inhibited even though intensive pushing in force acts on concerning a cap backward insertion fitting structure. SOLUTION: A cap is composed of a metallic outer cylinder 7 and a synthetic resin made inner cylinder 8. A plurality of projected parts 81 are arranged on an inner peripheral surface of an opening end of the inner cylinder 8. An annular recessed part 2 to which the projected parts 81 fit by sinking is provided onto an outer peripheral surface of a tail end part of a shaft cylinder 1. A slant control wall 5 is provided in front of the annular recessed part 2. A clearance S between a crest part of the control wall 5 and an inner peripheral surface of the outer cylinder 7 is set to be less than a wall thickness T in a radial direction of the projected part 81 of the inner cylinder 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap back insertion fitting structure for a writing instrument. More specifically, the present invention relates to a cap rear-insertion fitting structure in which a cap made of a synthetic resin inner cylinder fitted inside an outer cylinder is fitted to a tail end of a shaft cylinder.

[0002]

2. Description of the Related Art Conventionally, in this type of cap rear insertion fitting structure, for example, in Japanese Utility Model Publication No. 59-14237, a cylindrical member (corresponding to the outer cylinder of the present invention) is provided inside a cylindrical body of the cap (corresponding to the outer cylinder of the present invention). (Corresponding to the inner cylinder of the present invention) is fixed, and convex bulges (corresponding to the convex parts of the present invention) are provided on the inner surface near the free end of the tubular member at appropriate intervals on the circumference. Disclosed is a configuration in which a plurality of annular protrusions (corresponding to the annular recess of the present invention), which are formed in an array and whose bulging portions ride over and engage with each other, are formed at the tail end of the shaft cylinder.

In the structure of Japanese Utility Model Publication No. 59-14237 (see FIG. 7), when a strong pushing force is applied when the cap is fitted in the tail end portion of the shaft rearward, a convex portion on the inner surface of the inner cylinder 8a is applied. There is a possibility that 81a vigorously rides over the contact wall 5a on the front side of the annular recess 2a, and the inner diameter of the projection 81a exceeds the elastic deformation limit and is plastically deformed and spread. In particular, this easily occurs when the contact wall 5a on the front side of the annular recess 2a is an inclined surface. If the inner diameter of the convex portion 81a is largely plastically deformed in the radial direction, the fitting force between the convex portion 81a and the annular recess 2a (fitting force on the tail end side or the pen tip side)
Becomes loose, and the cap may easily come off.

In addition to this, actual fairness 3-31583
In the gazette, an inner fitting body (corresponding to the inner cylinder of the present invention) is mounted in a cap body (corresponding to the outer cylinder of the present invention), and the inner fitting body is brought into close contact with the inner surface of the cap body. On the inner surface of the opening end of the inner fitting body, a flange (corresponding to the annular recess of the present invention) at the rear end of the shaft cylinder and a locking projection (which corresponds to the projection of the present invention) that can be engaged and disengaged.
There is disclosed a cap rear insertion fitting structure provided with.

In the structure of Japanese Utility Model Publication No. 3-31583, since the outer peripheral surface of the inner cylinder near the convex portion is in close contact with the inner peripheral surface of the outer cylinder, the convex portion is fitted into the annular concave portion of the shaft cylinder. It does not expand and deform in the process of fitting (or over-fitting), and damage and damage such as crushing may occur on the convex parts even if the cap is removed and attached a small number of times, and the proper fitting force may not be maintained. is there. In particular, this tends to occur when the annular recess is made of a hard material such as metal. Also, the actual fairness 3-3
In the structure of Japanese Patent No. 1583, since the outer peripheral surface of the inner cylinder is in close contact with the inner peripheral surface of the outer cylinder as described above, the opening end of the inner cylinder peripheral wall provided with the convex portion is not elastically deformed radially outward, It is not possible to obtain a fitting feeling accompanied by a comfortable fitting sound (so-called patchy sound) at the time of the drop fitting.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art. When the cap is fitted in the tail end portion of the shaft rearward, the inner diameter of the convex portion of the inner cylinder is greatly expanded. It is an object of the present invention to provide a cap rear-insertion fitting structure that can maintain an appropriate fitting force for a long period of time without being deformed by opening or crushing a convex portion, and can provide a comfortable fitting feeling. In the present invention, the "front side" means
The pen tip side of the barrel or the open end side of the cap is shown, while the "rear side" is the tail end side of the barrel or the closed end side of the cap.

[0007]

Means for Solving the Problem Overview The present invention is a cap rear insertion fitting for fitting a cap 6 formed by attaching an inner cylinder 8 made of synthetic resin inside an outer cylinder 7 to a tail end portion of a shaft cylinder 1. In the combined structure, an annular gap 9 is formed between the outer peripheral surface of the open end of the inner cylinder 8 and the inner peripheral surface of the outer cylinder 7, and a convex portion 81 is provided on the inner peripheral surface of the open end of the inner cylinder 8. On the other hand, on the outer peripheral surface of the tail end portion of the shaft cylinder 1, an annular concave portion 2 into which the convex portion 81 is fitted is provided, and the front surface of the convex portion 81 is pressed against the front surface of the annular concave portion 2 by a cap pushing force. The wall 5 is provided, and the top of the restriction wall 5 and the outer cylinder 7 when the annular recess 2 and the protrusion 81 are in a fitted state.
The requirement is that the gap S with the inner peripheral surface is set to be smaller than the radial thickness T of the opening end of the inner cylinder 8.

Annular recess In the above configuration, the contact wall 3 of the annular recess 2 with which the front surface of the protrusion 81 is in pressure contact when the protrusion 81 and the annular recess 2 are in a fitted state may be formed in an inclined surface shape. preferable. Abutment wall 3
In the above case, in particular, the convex portion 81 has an inclined surface shape that allows the convex portion 81 to easily get over forward, and in particular, the above-described configuration (the gap S between the top of the restriction wall 5 and the inner peripheral surface of the outer cylinder 7 is set at the opening end of the inner cylinder 8). The expansion prevention effect of the configuration in which the thickness is set smaller than the radial thickness T) works effectively.

Further, in the above structure, it is preferable that the annular recess 2 (that is, the front contact wall 3 and the rear contact wall 4) is made of a metal material. As a result, when the convex portion 81 falls into the hard annular concave portion 2 and is fitted, the soft inner cylinder 8 made of synthetic resin is sufficiently elastically deformed, and a clear fitting feeling accompanied by a fitting sound is surely obtained. be able to. Also,
It is effective that the annular concave portion 2 is integrally formed on the peripheral wall of the metallic shaft cylinder 1 by inward plastic deformation in terms of easy manufacturing.

The outer diameter of the tail end of the barrel 1 behind the annular recess 2 (rear of the rear contact wall 4) is set slightly larger than the inner diameter of the projection 81. As a result, when the projection 81 is fitted into the annular recess 2 by fitting, the projection 81 rides over the outer peripheral surface of the tail end portion of the barrel 1 behind the annular recess 2, and then the rear surface of the projection 81 contacts the rear side. The cap 6 is pressed against the contact wall 4, and the cap 6 is reliably prevented from falling off.

Restriction Wall In the above-mentioned configuration, the restriction wall 5 preferably has an inclined surface shape. When the shape of the regulation wall 5 is the inclined surface shape where the convex portion 81 easily gets over the front, especially when the configuration (the gap S between the top portion of the regulation wall 5 and the inner peripheral surface of the outer casing 7 is set to the opening of the inner casing 8). The expansion prevention effect of the structure set to be smaller than the radial thickness T of the end) works effectively.

The restriction wall 5 may be formed in a continuously inclined plane shape from the front contact wall 3 to the front (FIGS. 3 and 4), or the step portion 11 may be formed from the front contact wall 3 to the front. It may be connected via (FIG. 5). When the regulation wall 5 is in the shape of an inclined plane, the inclination angle is effective in the range of 30 degrees to 80 degrees with respect to the axis. Further, the restriction wall 5 need only be an inclined surface, and is not a flat surface as shown in FIGS.
It may be formed into a curved surface shape.

Convex portion The convex portion 81 is formed integrally with the inner peripheral surface of the open end (including the vicinity of the open end) of the inner cylinder 8 in that it is more easily elastically deformed than the closed end side of the inner cylinder 8. Is preferred. The convex portion 81 may have a configuration in which it is formed in an annular shape on the inner peripheral surface of the inner cylinder 8 or a configuration in which a plurality of support protrusions are circumferentially dispersed and arranged at equal intervals. When the convex portion 81 is a plurality of supporting protrusions, the number thereof is preferably about 4 to 8. Also,
The vertical cross-sectional shape of the convex portion 81 is such that the front surface and the rear surface are R-shaped.
It may be a curved surface, a tapered surface, a right-angled surface, or the like, and examples of the overall shape include an arc shape, a trapezoidal shape, a rectangular shape, and a triangular shape.

Gap S, Wall Thickness T The gap S between the top of the restriction wall 5 and the inner peripheral surface of the outer cylinder 7 is the top of the restriction wall 5 (that is, the end of the restriction wall 5 when the projection 81 and the annular recess 2 are fitted together). (Part) and the inner peripheral surface of the outer cylinder 7 are defined. Further, the radial thickness T of the opening end (including the vicinity of the opening end) of the inner cylinder 8 is specifically the thickness including the projection 81 of the opening end peripheral wall or the projection 81 of the opening end peripheral wall. Either of the wall thicknesses not including is shown.

Annular Gap By providing the annular gap 9 between the outer peripheral surface of the opening end of the inner cylinder 8 and the inner peripheral surface of the outer cylinder 7, the convex portion 81 is formed at the time of the slip-fitting.
It facilitates elastic deformation in the radial direction of the opening end peripheral wall of the inner cylinder 8 provided with, and makes it easier for the convex portion 81 to ride over the tail end outer peripheral surface of the axial cylinder 1 behind the annular concave portion 2. Further, the clearance dimension of the annular clearance 9 when the convex portion 81 and the annular concave portion 2 are in the fitted state is
The inner diameter of the convex portion 81 is the maximum size that can be expanded, and the amount of expansion of the inner diameter of the convex portion 81 due to the convex portion 81 getting over the regulation wall 5 (that is, from the top of the convex portion 81 in the fitted state to the top of the regulating portion 5). (Radial distance up to) is set smaller than.

Material The inner cylinder 8 is effectively made of a relatively soft synthetic resin material such as polyethylene or polypropylene, and the outer cylinder 7
For example, a relatively hard metal material such as aluminum, stainless steel, brass, and nickel silver is effective.

(Operation) When the cap 6 is fitted in the tail end portion of the shaft cylinder 1 rearward, the annular gap 9 facilitates elastic deformation in the radial direction of the opening end peripheral wall of the inner cylinder 8 provided with the convex portion 81. Therefore, a comfortable and clear fitting feeling accompanied by a fitting sound is obtained.

When the cap 6 is fitted in the tail end portion of the shaft cylinder 1 (FIG. 3), the convex portion 81 on the inner peripheral surface of the inner cylinder 8 of the cap 6 is formed.
Is fitted into the annular recess 2 of the shaft cylinder 1 by being dropped. At this time, the front surface of the convex portion 81 is in pressure contact with the front contact wall 3, and at the same time, the rear surface thereof is in pressure contact with the rear contact wall 4.

When the cap 6 is pushed into the tail end of the barrel 1 more than necessary (FIG. 4), the projection 81 moves forward along the front contact wall 3 and is pressed against the restriction wall 5. At the same time, the opening end of the inner cylinder 8 is slightly elastically deformed in the radial direction due to the existence of the annular gap 9, and the outer peripheral surface of the opening end of the inner cylinder 8 is pressed against the inner peripheral surface of the outer cylinder 7. That is, the gap S between the top of the restriction wall 5 and the inner peripheral surface of the outer cylinder 7 is set to be smaller than the wall thickness T of the peripheral wall of the open end of the inner cylinder 8. ) Passes over the regulation wall 5 and the gap S
Therefore, the expansion deformation (plastic deformation) of the inner diameter of the convex portion 81 is reliably suppressed. As a result, the inner diameter and shape of the convex portion 81 (fitting portion) can be properly maintained for a long period of time even if a strong pushing force acts when the cap is fitted backward.

[0020]

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

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a first embodiment of a cap rear insertion fitting state, FIG. 2 is a longitudinal sectional view of a tail end portion of a shaft cylinder in a state where the cap of FIG. 1 is removed, and FIG. 3 is A of FIG. FIG. 4 is an enlarged vertical sectional view of a part, and is an enlarged sectional view when the cap pushing force of FIG. 3 is largely applied.

(Shaft cylinder) The shaft cylinder 1 is made of a thin-walled bottomed cylinder body (wall thickness 0.5 mm) made of aluminum. The tail end portion peripheral wall of the shaft cylinder 1 is deformed inward in a ring shape at one location by pressing the roller from the outer side to the inner side in the radial direction (by the rolling process). As a result, on the outer peripheral surface of the inwardly deformed portion,
An annular recess 2 that is recessed radially inward is integrally formed.
Further, the outer peripheral surface of the barrel 1 on the pen tip side is also formed with an annular concave portion 2 into which the convex portion 81 can be fitted so as to fit therein. still,
A ball-point pen refill is housed inside the barrel 1 and its pen tip is projected from the front end of the barrel 1 to the outside.

(Ring-shaped recess) As shown in FIG. 3, the ring-shaped recess 2 and the front contact wall 3 in the form of a slanted flat surface on which the front surface of the projection 81 is pressed and contacted with each other in the state of the recessed fitting with the projection 81. The rear surface of the portion 81 is provided with an inclined flat rear contact wall 4 that is in pressure contact with the rear surface. The front contact wall 3 is continuously extended forward,
The regulation wall 5 having an inclined surface is configured. The angle of the regulation wall 5 is set to 45 degrees with respect to the axis.

(Cap) The cap 6 comprises an outer cylinder 7 and an inner cylinder 8. Specifically, an outer cylinder 7 made of a metal (for example, aluminum) thin-walled bottomed cylinder having an outer surface to which a metal clip 71 is fixed, and a synthetic resin (for example, made of polyethylene, which is attached to the inside of the outer cylinder 7. ) Inner cylinder 8).

(Inner Cylinder) The inner cylinder 8 is fixed inside the outer cylinder 7 via a metal (for example, brass) mounting ring 73. The outer peripheral surface of the mounting ring 73 is the outer cylinder 7.
Is fixed to the closed inner wall of the inner cylinder 8 while the inner peripheral surface of the inner cylinder 8 is
It fits into an annular groove on the outer circumference of the top. A pen tip seal member 72 made of synthetic rubber is attached to the inner peripheral surface of the top of the inner cylinder 8 by press fitting. When the cap 6 is attached to the pen tip side of the barrel 1, the pen tip seal member 72 is brought into close contact with the ball of the pen tip of the ballpoint pen tip.

(Convex portion) On the inner peripheral surface of the opening end of the inner cylinder 8,
Four hemispherical convex portions 81 are integrally provided in a circumferential shape at equal intervals. The protrusion 81 is fitted into the annular recess 2 of the barrel 1 when the cap is inserted rearward.

(Gap S, Wall Thickness T) The projection 81 is formed in a hemispherical shape, and the wall thickness dimension T in the radial direction is 0.77.
It is set to 5 mm. On the other hand, the clearance dimension S between the top of the restriction wall 5 and the inner peripheral surface of the outer cylinder 7 is set to 0.35 mm. That is, since the gap S is set smaller than the wall thickness T (because the relationship of S <T is satisfied), even if a strong pushing force is applied, the convex portion 81 may get over the annular concave portion 2. It is prevented that the inner diameter of the opening end of the inner cylinder 8 (that is, the diameter of the virtual inscribed circle contacting the apex of the convex portion 81) is expanded. In other words, the restriction wall 5 and the inner peripheral surface of the barrel 1 cooperate with each other to function as a stopper in the mounting direction of the cap.

FIG. 5 shows a second embodiment of the present invention. The two-dot chain line shows the state of the inner tube 8 open end (mainly the convex portion 81) when a strong pushing force acts. This is a modification corresponding to the portion A of FIG. 1 of the first embodiment, and the regulating wall 5 having an inclined plane shape.
However, the front contact wall 3 is connected to the front through a slight step portion 11. Further, the hemispherical convex portion 81 is provided on the inner peripheral surface near the opening end of the inner cylinder 8. In the above configuration, the axial movement distance until the expansion of the opening end of the inner cylinder 8 is suppressed is increased by the provision of the step 11, but the effect of suppressing the expansion of the opening end of the inner cylinder 8 is suppressed. Is no different from the first embodiment.

FIG. 6 shows a third embodiment of the present invention. The two-dot chain line shows the state of the inner tube 8 open end (mainly the convex portion 81) when a strong pushing force acts. This is a modified example corresponding to the portion A of FIG. 1 of the first embodiment, in which the front contact wall 3, the rear contact wall 4, and the restriction wall 5 of the annular recess 2 are curved (concave curved or Convex curved surface). In the structure of the annular recess 2 and the restriction wall 5, the effect of suppressing the expansion of the opening end of the inner cylinder 8 is no different from that of the first embodiment.

[0030]

According to the cap rear fitting structure of the present invention, the inner diameter of the convex portion of the inner cylinder is greatly expanded or deformed when the cap is rear fitted into the tail end portion of the barrel. It is possible to maintain a proper fitting force for a long period of time without being crushed and to obtain a comfortable and clear fitting feeling.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a first embodiment of the present invention in a state where a cap is inserted backward from a cap.

FIG. 2 is a vertical cross-sectional view of the tail end portion of the shaft cylinder with the cap of FIG. 1 removed.

FIG. 3 is an enlarged vertical sectional view of a portion A in FIG.

FIG. 4A when the cap pushing force in FIG.
FIG.

FIG. 5 is an enlarged vertical sectional view of a main part of the second embodiment.

FIG. 6 is an enlarged vertical sectional view of a main part of the third embodiment.

FIG. 7 is an enlarged vertical sectional view of a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 shaft cylinder 11 step part 2 annular recessed part 3 front side contact wall 4 rear side contact wall 5 regulation wall 6 cap 7 outer cylinder 71 clip 72 nib seal member 73 mounting ring 8 inner cylinder 81 convex part 9 annular gap S gap T Thickness

Claims (3)

[Claims] 1. A cap rear insertion fitting for fitting a cap (6) formed by attaching an inner cylinder (8) made of synthetic resin inside an outer cylinder (7) to a tail end portion of a shaft cylinder (1). Structure,
An annular gap (9) is formed between the outer peripheral surface of the open end of the inner cylinder (8) and the inner peripheral surface of the outer cylinder (7), and a protrusion () is formed on the inner peripheral surface of the open end of the inner cylinder (8). 81), on the other hand, an annular recess (2) is provided on the outer peripheral surface of the tail end portion of the barrel (1) into which the projection (81) is fitted, and a cap is provided in front of the annular recess (2). A regulation wall (5) is provided, which is in pressure contact with the front surface of the convex portion (81) by the pushing force, and the regulation wall (5) when the annular concave portion (2) and the convex portion (81) are in a fitted state. Gap (S) between the top and the inner peripheral surface of the outer cylinder (7)
Is set to be smaller than the radial thickness (T) of the opening end of the inner cylinder (8). 2. An abutment wall (3) of an annular recess (2) with which the front surface of the protrusion (81) is in pressure contact when the projection (81) and the annular recess (2) are in a fitted state. The cap rear-insertion structure according to claim 1, which is formed on the. 3. The cap rear insertion fitting structure according to claim 2, wherein the restriction wall (5) has an inclined surface shape.