JP2002349519A - Method and structure for attaching middle shaft to outer shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attaching method for a middle shaft to be mounted to an outer shaft whereby it is possible to assure a wide applicable rang and good working efficiency without worsening the appearance. SOLUTION: The middle shaft 32 is inserted into the outer shaft 30, and an inner shaft 46 is inserted into the outer and middle shafts 30 and 32, a male threaded portion 46b formed on a tapered surface 46c on the peripheral surface of the inner shaft 46 is engaged with a femal threaded portion 32c formed on the inside surface of the middle shaft 32, followed by pushing wide a slit 32d formed in that part of middle shaft 32 where the female threads are provided, and that part on the middle shaft 32 is widened outward in the diametric direction to be pressed to the inside surface of the outer shaft 30, and thereby the middle shaft 32 is attached to the inside of the outer shaft 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a center shaft on an outer shaft and a structure for mounting the center shaft on an outer shaft. For example, an outer shaft for stationery, an outer shaft for cosmetics, or an outer shaft for a data input pen. The present invention relates to a mounting method and a mounting structure that can be applied to, for example, the present invention.

[0002]

2. Description of the Related Art Conventionally, there is a case where it is necessary to mount a center shaft as a single component in an outer shaft. In such a case, a method of mounting the center shaft to the outer shaft is by screwing, bonding or engaging. Is generally known. Screwing is a method in which a female screw is formed on the inner peripheral surface of the outer shaft, a male screw is formed on the outer peripheral surface of the central shaft, and the male screw of the central shaft is screwed with the female screw of the outer shaft. Adhesion is a method in which a liquid or gel adhesive is applied to the outer peripheral surface of the center shaft, the center shaft is inserted into an appropriate position in the outer shaft, and then the adhesive is dried and fixed.
As the engagement, there is a method in which an opening is formed in the peripheral surface of the outer shaft, an engaging piece is formed in the center shaft, and the engaging piece of the center shaft is engaged with the opening of the outer shaft to lock.

[0003]

However, in such a conventional mounting method, in order to perform screwing, the outer shaft and the center shaft must be in a relative rotatable relationship. In use, it is necessary to satisfy the condition that the outer shaft and the center shaft must rotate relative to each other so as not to be taken carelessly, and there is a problem that the applicable range is limited. Alternatively, when a female screw or the like cannot be formed on the outer shaft, it cannot be applied.

On the other hand, liquid or gel bonding requires a long time to dry and completely fix, and it is necessary to work carefully to prevent the adhesive from adhering to other members, resulting in poor working efficiency. There is.

[0005] In addition, since the engagement requires forming an opening in the outer shaft, there is a problem that the appearance of the outer shaft deteriorates.

The present invention has been made in view of such conventional problems, and has a wide application range, good work efficiency, and a method of attaching a center shaft to an outer shaft without deteriorating the external appearance. It is an object of the present invention to provide a mounting structure for an outer shaft.

[0007]

In order to achieve the above object, an invention according to claim 1 of the present invention is a mounting method for mounting a center shaft inside an outer shaft, wherein the center shaft is inserted into the outer shaft. The auxiliary shaft is inserted into the outer shaft and the center shaft, and the female screw formed on the inner surface of the center shaft is screwed with the male screw formed on the outer surface of the auxiliary shaft to form a tapered auxiliary. As the screwing of the auxiliary shaft and the central shaft is advanced by the male threaded portion of the shaft or the female threaded portion of the tapered central shaft, the slit formed in the female threaded portion of the central shaft is pushed open, The inner shaft is attached to the inside of the outer shaft by expanding the female threaded portion of the outer shaft in the outer diameter direction and pressing the inner shaft of the outer shaft.

According to a second aspect of the present invention, in the first aspect, a projection which is pressed against an inner peripheral surface of the outer shaft is formed on an outer peripheral surface of the female threaded portion of the center shaft. According to a third aspect of the present invention, in the first or second aspect, an adhesive tape or an elastic body is interposed between the outer peripheral surface of the female threaded portion of the center shaft and the inner peripheral surface of the outer shaft. .

According to a fourth aspect of the present invention, there is provided a mounting method for mounting a center shaft inside an outer shaft, wherein the center shaft is located inside the outer shaft, the elastic ring is adjacent to the center shaft in the axial direction, and the auxiliary ring is adjacent to the auxiliary ring. Insert the auxiliary shaft, penetrate a part of the auxiliary shaft or part of the central shaft through the elastic ring, and form the female screw formed on one of the central shaft and the auxiliary shaft and the other on the other of the central shaft and the auxiliary shaft As the auxiliary screw is screwed and the auxiliary shaft is moved toward the center shaft, the elastic ring is axially compressed between the auxiliary shaft and the center shaft, and the elastic ring is pressed against the inner peripheral surface of the outer shaft. Then, the middle shaft is attached to the inside of the outer shaft by fixing the elastic ring to the outer shaft.

According to a fifth aspect of the present invention, in the fourth aspect, the auxiliary shaft is provided with a step surface which is in contact with the elastic ring, and the step surface is inclined in an outer diameter direction. Surface.

According to a sixth aspect of the present invention, there is provided a mounting method for mounting the center shaft on the inside of the outer shaft, wherein the annular recess formed on the inner circumferential surface of the outer shaft projects inward from the inner circumferential surface of the outer shaft. Insert the C-ring into the outer shaft, insert a part of the center shaft from one end of the outer shaft into the outer shaft, and contact the end of the portion not inserted into the outer shaft of the middle shaft to one end of the outer shaft, Insert the auxiliary shaft into the outer shaft from the other end of the outer shaft, pass a part of the auxiliary shaft or part of the center shaft through the C-ring, and insert the female screw formed in either the center shaft or the auxiliary shaft. A part of the C-ring projecting beyond the inner peripheral surface of the outer shaft of the C-ring by screwing a male screw formed on the other of the center shaft and the auxiliary shaft and moving the auxiliary shaft toward the middle shaft. By contacting the other end of the outer shaft with
Install the center shaft inside the outer shaft.

According to a seventh aspect of the present invention, there is provided a mounting structure in which a center shaft is mounted inside an outer shaft with the aid of an auxiliary shaft, and a female screw is formed on an inner peripheral surface of the center shaft. A slit is formed in the female threaded portion, a male thread is formed on the outer peripheral surface of the auxiliary shaft, and a male threaded portion of the auxiliary shaft or a female threaded portion of the center shaft is formed in a tapered shape,
The male screw of the auxiliary shaft inserted into the outer shaft and the central shaft is screwed into the female screw of the central shaft inserted into the outer shaft, and the slit of the central shaft is pushed out, so that the female-threaded portion is removed. By being pressed against the inner peripheral surface of the shaft and fixing the center shaft to the outer shaft,
The middle shaft is mounted inside the outer shaft.

According to an eighth aspect of the present invention, in the seventh aspect, a projection which is pressed against an inner peripheral surface of the outer shaft is formed on an outer peripheral surface of the female threaded portion of the center shaft. According to a ninth aspect of the present invention, in the seventh or eighth aspect, an adhesive tape or an elastic body is interposed between the outer peripheral surface of the female threaded portion of the center shaft and the inner peripheral surface of the outer shaft. .

According to a tenth aspect of the present invention, there is provided a mounting structure in which a center shaft is mounted inside an outer shaft with the aid of an auxiliary shaft and an elastic ring, and a female screw is formed on one of the center shaft and the auxiliary shaft. A male screw is formed on one of the other ends to be screwed with the female screw. A middle shaft and an elastic ring are inserted in the outer shaft adjacent to the middle shaft in the axial direction. The auxiliary shaft is inserted from, a part of the auxiliary shaft or a part of the middle shaft penetrates through the elastic ring, the middle shaft and the auxiliary shaft are coupled by screwing the male screw and the female screw, The elastic ring is compressed in the axial direction between the auxiliary shaft and the central shaft, and the elastic ring is pressed against the inner peripheral surface of the outer shaft and the elastic ring is fixed to the outer shaft. It is attached to.

According to an eleventh aspect of the present invention, in accordance with the tenth aspect, the auxiliary shaft is provided with a stepped surface abutting on the elastic ring, and the stepped surface is inclined in an outer radial direction. Surface.

According to a twelfth aspect of the present invention, there is provided a mounting structure in which a center shaft is mounted inside an outer shaft with the aid of an auxiliary shaft and a C-ring, and an annular concave portion is formed on an inner peripheral surface of the outer shaft. A C-ring is fitted into the annular recess so as to protrude in the inner diameter direction from the inner peripheral surface of the outer shaft, and a female screw is formed on one of the middle shaft and the auxiliary shaft, and the other is formed on the other. A male screw to be screwed with the female screw is formed, a part of the center shaft is inserted into the outer shaft, and an end of a portion that is not inserted into the outer shaft of the center shaft is in contact with one end of the outer shaft, An auxiliary shaft is inserted into the outer shaft from the other end of the outer shaft, and a part of the auxiliary shaft or a part of the middle shaft penetrates through the C-ring, and the male screw and the female screw are screwed into each other. And the auxiliary shaft are connected to each other, and the auxiliary shaft protrudes from the inner peripheral surface of the outer shaft of the C-ring at the other end of the outer shaft. By being Luo abut the center shaft is mounted inside of the outer shaft.

According to the present invention, the center shaft can be attached to the outer shaft with the aid of the auxiliary shaft, mainly by a simple operation of screwing the center shaft and the auxiliary shaft together without deteriorating the appearance of the outer shaft. It is also applicable when the center shaft is not rotatable relative to the outer shaft, when the outer shaft or the center shaft cannot be screwed, or when the center shaft or the outer shaft is made of a non-adhesive material. Yes, and the range of application can be expanded.

In the case where a projection pressed against the inner peripheral surface of the outer shaft is formed on the outer peripheral surface of the female threaded portion of the central shaft, the projection can increase the coupling force between the central shaft and the outer shaft. Further, by interposing an adhesive tape or an elastic body between the outer peripheral surface of the female threaded portion of the center shaft and the inner peripheral surface of the outer shaft, the coupling force between the center shaft and the outer shaft can be further increased. .

When the center shaft is attached to the outer shaft with the aid of the auxiliary shaft and the elastic ring, the elastic ring elastically contacts the auxiliary shaft and / or the center shaft to inhibit relative rotation between the auxiliary shaft and the center shaft. Furthermore, loosening of the screw between the auxiliary shaft and the middle shaft is prevented, and the middle shaft is securely attached to the outer shaft. In addition, when a step surface that contacts the elastic ring is formed on the auxiliary shaft, and the step surface is an inclined surface facing the outer diameter direction,
The closer the auxiliary shaft is to the elastic ring, the more the elastic ring can be pressed against the outer radial direction, that is, against the inner peripheral surface of the outer shaft.

When the center shaft is attached to the outer shaft with the aid of the auxiliary shaft and the C-ring, the auxiliary shaft is brought into contact with the C-ring from the other end of the outer shaft and inserted into the outer shaft of the center shaft. By contacting the missing portion with one end of the outer shaft, the center shaft can be securely attached to the outer shaft. When a part of the auxiliary shaft or a part of the center shaft penetrating the C ring comes into frictional contact with the C ring, the loosening of the screw between the auxiliary shaft and the center shaft is prohibited in order to inhibit the relative rotation of the auxiliary shaft and the center shaft. Is prevented, and the center shaft is securely attached to the outer shaft.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The present invention can be applied to an outer shaft for stationery, an outer shaft for cosmetics, an outer shaft for a data input pen, and the like. In the following, a case where the present invention is applied to a writing implement will be described as an example. I do.

FIG. 1 is an overall vertical sectional view showing an embodiment in which a mounting method and a mounting structure of the present invention are applied to a cap 14 of a writing instrument 10.

The writing implement 10 includes a writing implement main body 12 and a cap 14 detachably attached to the writing implement main body 12. The writing implement body 12 incorporates a refill 16 having a ball at the tip 16a and containing ink. The cap 14 prevents evaporation and drying of the ink in the refill 16 and protects the tip 16a when the refill 16 is not used.
At the same time, a plurality of holding bodies 21 and 22 are housed, and these holding bodies 21 and 22 can be selectively used from the tip of the cap 14 so as to be usable. Here, the holder is a medium for stationery (eg, writing ink, writing core, eraser, solid glue, correction liquid), a medium for makeup (eg, lipstick, eye pencil, eye liner,
An eyebrow pencil) or a medium that holds a data input medium (for example, a stylus chip) or the like. In the illustrated embodiment, ballpoint pen refills are used as the holders 21 and 22.

The cap 14 includes an outer shaft 30 and a center shaft 32.
And a leading tool 34. In the following description, the front tool 34 side is the front (front) side, and the opposite side is the rear side. The rear end of the central shaft 32 is inserted and fixed in the outer shaft 30, and an inner shaft 46 serving as an auxiliary shaft is provided inside the central shaft 32.
(Auxiliary shaft) is fixed. As described later, the center shaft 32
With the help of the inner shaft 46, it is integrally attached to the outer shaft 30. The inner space of the inner shaft 46 is the writing implement main body 1.
The space in which the tip 16a of the second refill 16 is stored.

As shown in FIG. 2, the outer shaft 30 of the center shaft 32
A tip exposed to the outside without being inserted into the inside;
Is not a perfect circular shape perpendicular to the axial direction, but an elliptical shape inclined at an angle to the axial direction. Therefore, the outer shaft 3
0 and the center shaft 32 cannot rotate relative to each other. The base of the clip 36 is sandwiched between the center shaft 32 and the outer shaft 30 at the tip of the inclined boundary circle.

The leading tool 34 is disposed at the distal end of the center shaft 32 so as to be rotatable relative to the center shaft 32. That is, the leading tool 3
Numeral 4 is screwed to a screw portion formed on the outer peripheral surface of the distal end of the slide receiver 40 provided in the center shaft 32. In the screwed state, the leading tool 34 and the slide receiver 40 rotate integrally. It has become. The tips of the holders 21 and 22 are selectively projected from the tip opening 34a at the tip of the tip 34.

The slide receiver 4 screwed to the tip 34
0 extends in the axial direction inside the central shaft 32. Locking pieces 40a, 40a are formed at the rear end of the slide receiver 40. These locking pieces 40a, 40a are rotatable relative to a step 32b formed at the rear end of the center shaft 32. Locked. Further, the head 46a of the inner shaft 46 fits further inward in the radial direction of the locking pieces 40a, 40a, thereby preventing the locking pieces 40a, 40a from falling inward in the radial direction. The locking piece 40a is prevented from coming off the step 32b.

Further, a plurality of guide grooves 40b extending in the axial direction are formed in the slide receiver 40 in accordance with the number of the holding bodies 21 and 22 to be stored.
The holding bodies 21 and 22 are disposed so as to be movable in the axial direction in the inside b. That is, a holder receiver 50 is provided at the rear end of the holders 21 and 22, and the holder receiver 50 is
2, and the slider 52 is slidably fitted in the guide groove 40 b of the corresponding slide receiver 40.

An axially inclined cam surface 32a is formed on the inner peripheral surface on the distal end side of the center shaft 32. The cam surface 32a is formed of a stepped surface facing forward and is inclined in the axial direction.
2a. The slider 52 is slidable along the cam surface 32a. In order to make this slider 52 abut against the cam surface 32a,
A return spring 54 is interposed between the slider 52 and the partition wall 40c of the slide receiver 40, and the return spring 54 urges the slider 52 rearward.

When one of the holders 21 and 22 is used, the following operation is performed. That is, the leading tool 34 is rotated in a predetermined direction with respect to the outer shaft 30 and the center shaft 32. Thus, the slide receiver 40 that rotates integrally with the leading tool 34 rotates in a predetermined direction with respect to the center shaft 32, and the slide receiver 40 rotates.
Sliders 52, 52 fitted in the guide grooves 40b of
As a result, each of the sliders 52 moves in the axial direction along the cam surface 32a of the center shaft 32, so that one of the two sliders 52 moves forward and the other moves backward. Assuming that the holder 50 of the holder 21 is supported by the slider 52 that has moved forward, the holder 21 advances with the slider 52.

The slider 52, which has advanced along the cam surface 32a, stops at the advanced position when locked by the locking portion at the tip of the cam surface 32a. In this way, as shown in FIG. 3, the tip of the holder 21 supported by the slider 52 is held in a state of protruding from the tip opening 34a, and the holder 21 can be used. The slider 52 supporting the holder receiver 50 of the other holder 22 retreats along the cam surface 32a, and the tip of the holder 22 supported by the slider 52 retracts.

Incidentally, in order to perform the above operation reliably, it is necessary that the center shaft 32 having the cam surface 32a is securely and integrally attached to the outer shaft 30. This mounting structure and mounting method are performed as follows.

As shown in FIGS. 4 and 5, a female screw 32c is formed on the inner peripheral surface of the rear end of the central shaft 32, and the female screw 32c is formed on the central shaft 32. A pair of opposed slits 32d extending in the axial direction from the ends are formed in the female threaded portion. The number of the slits 32d is not limited to a pair as in this example, but may be one or three or more. A plurality of projections 32e extending in the axial direction are formed on the outer peripheral surface of the female threaded portion of the center shaft 32, which are appropriately spaced in the circumferential direction. An elastic ring (elastic body) 44 may be further attached to the outer peripheral surface of the female threaded portion of the center shaft 32. The elastic ring 44 can be made of an elastomer, a soft synthetic resin, or the like.

As shown in FIG. 4 and FIG. 6, the inner thread 32c is provided on the outer peripheral surface of the tip (part) of the inner shaft 46.
The outer peripheral surface of the externally threaded portion is a tapered surface 46c whose outer diameter gradually increases from the front end toward the rear. Also,
On the inner circumferential surface of the inner shaft 46, tool grooves 46d for inserting a tool such as a screwdriver used for mounting work are formed at appropriate intervals in the circumferential direction.

The mounting operation is performed as follows. First, center axis 3
2 insert the rear end into the outer shaft 30 and position it in a suitable position. Next, the inner shaft 46 is inserted into the outer shaft 30 and the center shaft 32, a tool is inserted into a tool groove 46d on the inner peripheral surface of the inner shaft 46, and the inner shaft 46 is rotated. The male screw 46b is screwed into the female screw 32c in the center shaft 32. As the screwing continues, the tapered surface 46 of the inner shaft 46
As a result, the slit 32d at the rear end of the central shaft 32 is pushed open, so that the female threaded portion of the central shaft 32 expands in the outer diameter direction. It is pushed. At this time, the elastic ring 44 mounted on the outer peripheral surface of the female threaded portion of the central shaft 32 is compressed by being interposed between the outer peripheral surface of the central shaft 32 and the inner peripheral surface of the outer shaft 30.

Thus, the rear end of the center shaft 32 is
And the center shaft 32 is securely attached to the outer shaft 30. In this manner, without deteriorating the appearance of the outer shaft 30 and without requiring time such as bonding,
Work can be performed with high work efficiency. In addition, center axis 3
Since the projections 32e formed separately on the outer peripheral surface of the outer shaft 2 further press the elastic ring 44 against the outer peripheral surface of the outer shaft 30, the frictional force between the outer ring 30 and the outer peripheral surface of the outer shaft 30 is increased, and the coupling force is increased. Can be enhanced. However, instead of the elastic ring 44, a double-sided or single-sided adhesive tape may be interposed between the outer peripheral surface of the central shaft 32 and the inner peripheral surface of the outer shaft 30. The adhesive tape can be a pressure-sensitive adhesive tape. When an adhesive tape is used, it may be preferable to omit the projection 32e on the outer peripheral surface of the center shaft 32. Optionally, the outer peripheral surface of the central shaft 32 may be directly pressed against the inner peripheral surface of the outer shaft 30 without using any adhesive tape and the elastic ring 44.

In the illustrated example, the outer peripheral surface of the portion of the inner shaft 46 with external threads is tapered. However, the inner peripheral surface of the female threaded portion of the central shaft 32 is tapered, and as the screwing with the internal shaft 46 progresses, the slit 32d of the central shaft 32 is pushed open, and the female threaded portion of the central shaft 32 is expanded. Can be made to spread in the outer diameter direction.

Next, FIG. 8 is a diagram showing a second embodiment of the present invention. In the drawings, the same members as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

This embodiment is different from the first embodiment in that the elastic ring 48 is disposed in the outer shaft 30 adjacent to the center shaft 32-1. That is, the elastic ring 48
A stepped surface 46 formed on the rear end surface of the central shaft 32-1 and the outer peripheral surface of a portion not inserted into the central shaft 32-1 of the internal shaft 46-1.
e. The elastic ring 48 can be made of an elastomer, a soft synthetic resin, or the like.

A slit 32d may be formed at the rear end of the center shaft 32-1 as in the first embodiment. However, in this embodiment, the slit 32d may be omitted.

The step surface 46e of the inner shaft 46-1 may be a vertical surface perpendicular to the axial direction, but is preferably an inclined surface. And the inclined surface is the elastic ring 48.
And a surface facing the outer diameter direction. The outer peripheral surface of the tip of the inner shaft 46-1 is:
It is not necessary to use the tapered surface 46c as in the first embodiment, and it may be a surface parallel to the axial direction.

The mounting operation in this embodiment is performed as follows. First, the rear end of the center shaft 32-1 is inserted into the outer shaft 30 and positioned at an appropriate position, and similarly, the elastic ring 48 is inserted into the outer shaft 30 to be adjacent to the center shaft 32-1. Then, the inner shaft 46-1 is inserted into the outer shaft 30, and the distal end of the inner shaft 46-1 is made to penetrate through the elastic ring 48 so that
2-1, the tool is inserted into the tool groove 46d on the inner peripheral surface of the inner shaft 46-1, and the inner shaft 46-1 is rotated. Screw 46b to the center shaft 3
Screw into the female screw 32c in 2-1. When the screwing is continued and the inner shaft 46-1 is moved toward the center shaft 32-1, the step surface 46e of the inner shaft 46-1 comes into contact with the rear end surface of the elastic ring 48, and the elastic ring 48 32-1 and inner shaft 46
-1 and is compressed in the axial direction by being sandwiched between the step surface 46e. As a result, the elastic ring 48 is expanded in the radial direction, and the elastic ring 48 is pressed against the inner peripheral surface of the outer shaft 30. At this time, since the step surface 46e of the inner shaft 46-1 is an inclined surface facing the outer diameter direction, the step surface 46e is formed.
The closer the e is to the elastic ring 48, the more the elastic ring 48 is pressed radially outward. Thus, the elastic ring 48 is fixed in the outer shaft 30 and the elastic ring 48 is fixed.
The center shaft 32-1 and the inner shaft 46-1 are screwed together so that the rear end of the center shaft 32-1 cannot move with respect to the outer shaft 30. It is firmly attached to.

Further, a force that pushes and expands in all directions acts on the compressed elastic ring 48, and the elastic ring 48 elastically contacts the center shaft 32-1 and the inner shaft 46-1.
A frictional force is generated between them. The frictional force prevents the center shaft 32-1 and the inner shaft 46-1 from being rotated carelessly, and prevents the screwing between the inner shaft 46-1 and the center shaft 32-1 from being loosened.

The elastic ring 48 is not limited to one having a length in the axial direction, but may be an O-ring 48-1 having a short length as shown in FIG. 9 as a modification of the second embodiment. Of course, it can be made to work similarly.

In the embodiment shown in FIGS. 8 and 9, the female screw 32c of the central shaft 32-1 and the male screw 46b of the internal shaft 46-1 are screwed together to form the central shaft 32-1 and the internal shaft 46. However, the present invention is not limited to this, and it is also possible to form a male screw on the central shaft and a female screw screwed on the male screw of the central shaft. It is also possible to connect the center shaft and the inner shaft by passing the rear end of the center shaft, not the front end of the inner shaft, through the elastic ring 48.

Next, FIG. 10 is a diagram showing a third embodiment of the present invention. In the drawings, the same members as those of the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

An annular recess 30a is formed on the inner peripheral surface of the outer shaft 30-2 of this embodiment. Then, a C ring 49 is fitted into the annular concave portion 30a. C
The ring 49 can be made of any material of metal or resin, and is made of a ring in which one cut is formed as shown in FIG.
The diameter can be reduced. Therefore, when performing the work of fitting the C-ring 49 into the annular concave portion 30a of the outer shaft 30-2, after moving the C-ring 49 to the annular concave portion 30a while compressing the C-ring 49 inside the outer shaft 30-2 in the inner diameter direction, It can be fitted into the annular recess 30a. C ring 49
In the state of being fitted in the annular concave portion 30a, the innermost side portion of the outer shaft 30-2 protrudes from the inner peripheral surface of the outer shaft 30-2 other than the annular concave portion 30a in the inner diameter direction.

On the outer peripheral surface of the inner shaft 46-2, there is formed a step surface 46f which comes into contact with the C-ring 49 projecting in the inner diameter direction.

It is not necessary to form a slit 32d at the rear end of the center shaft 32-2 as in the first embodiment.
The outer peripheral surface of the distal end of the inner shaft 46-2 does not need to be the tapered surface 46c as in the first embodiment.

The mounting operation in this embodiment is performed as follows. First, the C-ring 49 is previously fitted in the annular recess 30a of the outer shaft 30-2 as described above. Next, the rear end of the central shaft 32-2 is inserted from the distal end of the outer shaft 30-2, and the stepped surface 32f serving as the boundary between the distal end and the rear end of the central shaft 32-2 is inserted into the outer shaft 30-2. It is brought into contact with the tip surface 30b. At this time, the rear end, which is the insertion end of the center shaft 32-2, and C
Desirably, the ring 49 is separated from the ring 49 in the axial direction. Then, the inner shaft 46-2 is inserted from the rear end of the outer shaft 30-2, and the tip of the inner shaft 46-2 is inserted through the C-ring 49 into the center shaft 32-2, and the tool is inserted into the inner shaft 32-2. Inserting into the tool groove 46d on the inner peripheral surface of the shaft 46-2 and rotating the inner shaft 46-2, the male screw 46b at the tip of the inner shaft 46-2
Is screwed into the female screw 32c in the center shaft 32-2. When the screwing is continued and the inner shaft 46-2 is moved toward the center shaft 32-2, the step surface 46f of the inner shaft 46-2 is
9, the inner shaft 46-2 cannot be moved toward the center shaft 32-2 any further. In this state, the center shaft 32-2 and the inner shaft 46-2, which are connected by screwing, sandwich the front end surface 30b of the outer shaft 30-2 and the rear end surface of the C ring 49, and as a result, the center shaft 3
2-2 is securely attached to the outer shaft 30-2. According to this embodiment, the center shaft 32-2 is more reliably connected to the outer shaft 30-
2 attached. The inner diameter of the C-ring 49 and the outer diameter of the distal end of the inner shaft 46-2 are set so that the distal end of the inner shaft 46-2 penetrating the C-ring 49 contacts the inner peripheral surface of the C-ring 49. In this case, a frictional force is generated between the two shafts, and the frictional force prevents the inner shaft 46-2 from rotating carelessly.
-2 is prevented from loosening.

In the embodiment shown in FIG. 10, the female screw 32c of the center shaft 32-2 and the male screw 46b of the inner shaft 46-2 are used.
Are screwed into each other so that the center shaft 32-2 and the inner shaft 46-2
However, the present invention is not limited to this, and it is also possible to form a male screw on the central shaft and a female screw screwed on the male screw of the central shaft. It is also possible to connect the center shaft and the inner shaft by penetrating the rear end of the center shaft instead of the front end of the inner shaft through the C-ring 49.

The above description has been given of the case where the present invention is applied to the cap of the writing implement. However, it has already been described that the present invention can be applied to an outer shaft for a stationery or a cosmetic other than the writing implement other than the cap. It is on the street.

[0053]

As described above, according to the present invention,
Since the center shaft is attached to the outer shaft by screwing the center shaft and the auxiliary shaft, the center shaft can be mounted to the outer shaft with a simple operation with good work efficiency and without deteriorating the appearance of the outer shaft. The present invention can also be applied to a case where the center shaft is not rotatable relative to the outer shaft, or a case where the center shaft or the outer shaft is made of a non-adhesive material.

[Brief description of the drawings]

FIG. 1 is an overall longitudinal sectional view illustrating an embodiment in which the present invention is applied to a writing instrument cap.

FIG. 2 is an overall view of the writing instrument of FIG. 1;

FIG. 3 is an overall longitudinal sectional view showing an embodiment of the writing instrument cap according to the present invention, in which a tip of a holder is protruded.

FIG. 4 is an enlarged sectional view showing the mounting structure of FIG.

FIG. 5 is a view showing a center shaft in the mounting structure of FIG. 1;
(A) is a plan view, (b) is a cross-sectional view, and (c) is 5c-5c.
It is sectional drawing seen along.

6 is a diagram showing an inner shaft in the mounting structure of FIG. 1,
(A) is a plan view and (b) is a cross-sectional view.

FIG. 7 is a cross-sectional view corresponding to FIG. 4, illustrating the process of assembling the first embodiment.

FIG. 8 is a cross-sectional view illustrating a mounting structure according to a second embodiment of the present invention.

FIG. 9 is a sectional view illustrating a modification of the second embodiment of the present invention.

FIG. 10 is a sectional view illustrating a mounting structure according to a third embodiment of the present invention.

11 is a front view of a C-ring used in FIG.

[Description of Signs] 30, 30-2 Outer shaft 30b Tip surface 32, 32-1, 32-2 Center shaft 32c Female screw 32d Slit 32e Projection 32f Step surface 44 Elastic body 46, 46-1, 46-2 Inner shaft ( Auxiliary shaft) 46b Male thread 46c Tapered surface 46e Step surface 48 Elastic ring 48-1 O ring (elastic ring) 49 C ring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadayoshi Ebinuma 138 Kurei, Kawagoe-shi, Saitama F-term in the Kotobukigawago factory (reference) 3J039 AA03 AB05 BB01 GA20 5B068 AA36 BD02

Claims (12)

[Claims] 1. A mounting method for mounting a center shaft inside an outer shaft, wherein the center shaft is inserted into the outer shaft, and an auxiliary shaft is inserted into the outer shaft and the center shaft. The male screw formed on the outer peripheral surface of the auxiliary shaft is screwed into the female screw, and the male screw part of the tapered auxiliary shaft or the female screw part of the tapered middle shaft As the screwing of the shaft and the center shaft progresses, the slit formed in the center-threaded portion with a female thread is expanded, and the center-threaded portion with a female thread is expanded in the outer diameter direction and pressed against the inner peripheral surface of the outer shaft. How to attach the middle shaft inside the outer shaft. 2. The mounting method according to claim 1, wherein a projection that is pressed against an inner peripheral surface of the outer shaft is formed on an outer peripheral surface of the female threaded portion of the center shaft. 3. The mounting method according to claim 1, wherein an adhesive tape or an elastic body is interposed between an outer peripheral surface of the female threaded portion of the center shaft and an inner peripheral surface of the outer shaft. 4. A mounting method for mounting a center shaft inside an outer shaft, comprising: a center shaft inside the outer shaft; an elastic ring axially adjacent to the center shaft;
And an auxiliary shaft is inserted adjacent to the elastic ring, a part of the auxiliary shaft or a part of the intermediate shaft is penetrated through the elastic ring, and a female screw formed on one of the central shaft and the auxiliary shaft is inserted into the auxiliary shaft and the auxiliary shaft. As the male screw formed on one of the other shafts is screwed together and the auxiliary shaft is moved toward the central shaft, the elastic ring is axially compressed between the auxiliary shaft and the central shaft, and the elastic ring is removed. A mounting method in which the center shaft is attached to the inside of the outer shaft by pressing against the inner peripheral surface of the shaft and fixing the elastic ring to the outer shaft. 5. The mounting method according to claim 4, wherein the auxiliary shaft has a stepped surface that contacts the elastic ring, and the stepped surface is an inclined surface facing the outer diameter direction. 6. A mounting method for attaching a center shaft to the inside of an outer shaft, wherein a C-ring is inserted into an annular concave portion formed on an inner circumferential surface of the outer shaft so as to protrude in an inner diameter direction from an inner circumferential surface of the outer shaft. A part of the middle shaft is inserted into the outer shaft from one end of the outer shaft, and one end of the outer shaft is brought into contact with one end of the middle shaft that is not inserted into the outer shaft. A part of the auxiliary shaft or a part of the middle shaft is inserted through the C ring, and the female screw formed on one of the center shaft and the auxiliary shaft is inserted into the female screw formed on one of the middle shaft and the auxiliary shaft. The male screw formed on one of the other ends is screwed together, the auxiliary shaft is moved toward the center shaft, and the auxiliary shaft is protruded from the inner peripheral surface of the outer shaft of the C ring at the other end of the outer shaft. A mounting method in which the center shaft is attached to the inside of the outer shaft by abutting from the side. 7. A mounting structure in which a center shaft is mounted inside an outer shaft with the aid of an auxiliary shaft, wherein a female screw is formed on an inner peripheral surface of the middle shaft, A slit is formed, an external thread is formed on the outer peripheral surface of the auxiliary shaft, and a male threaded portion of the auxiliary shaft or a female threaded portion of the middle shaft is formed in a tapered shape, and the middle shaft inserted into the outer shaft is formed. The female screw is screwed with the male screw of the auxiliary shaft inserted in the outer shaft and the center shaft, the slit of the center shaft is expanded, and the female threaded portion is pressed against the inner peripheral surface of the outer shaft. By fixing the center shaft to the outer shaft,
Mounting structure in which the center shaft is mounted inside the outer shaft. 8. The mounting structure according to claim 7, wherein a projection is formed on an outer peripheral surface of the internally threaded portion of the center shaft to be pressed against an inner peripheral surface of the outer shaft. 9. The mounting structure according to claim 7, wherein an adhesive tape or an elastic body is interposed between an outer peripheral surface of the female threaded portion of the center shaft and an inner peripheral surface of the outer shaft. 10. A mounting structure in which a center shaft is mounted inside an outer shaft with the assistance of an auxiliary shaft and an elastic ring, wherein a female screw is formed on one of the center shaft and the auxiliary shaft and the other is mounted on the other. A male screw that is screwed with the female screw is formed, a middle shaft and an elastic ring are inserted into the outer shaft in the axial direction adjacent to the middle shaft, and an auxiliary shaft is inserted into the outer shaft from the elastic ring side. A part of the auxiliary shaft or a part of the central shaft penetrates through the elastic ring, and the male shaft and the female shaft are screwed together to connect the central shaft and the auxiliary shaft. The elastic ring is compressed in the axial direction, the elastic ring is pressed against the inner peripheral surface of the outer shaft, and the elastic ring is fixed to the outer shaft, so that the middle shaft is mounted inside the outer shaft. Construction. 11. The mounting structure according to claim 10, wherein a step surface is formed on the auxiliary shaft to contact the elastic ring, and the step surface is an inclined surface facing in an outer radial direction. 12. A mounting structure in which a center shaft is mounted inside an outer shaft with the aid of an auxiliary shaft and a C-ring, wherein an annular recess is formed on an inner peripheral surface of the outer shaft, and the annular recess is formed in the annular recess. The C-ring is fitted so as to protrude in the radial direction from the inner peripheral surface of the outer shaft. A female screw is formed on one of the central shaft and the auxiliary shaft, and the other is screwed with the female screw on the other. A male screw is formed, a part of the center shaft is inserted into the outer shaft, and one end of the outer shaft is brought into contact with one end of the center shaft that is not inserted into the outer shaft. The auxiliary shaft is inserted from the other end of the shaft, a part of the auxiliary shaft or a part of the central shaft penetrates through the C-ring, and the male shaft and the female shaft are screwed together to connect the middle shaft and the auxiliary shaft. And the auxiliary shaft is brought into contact with a portion of the C-ring projecting beyond the inner peripheral surface of the outer shaft from the other end of the outer shaft. More,
Mounting structure in which the center shaft is mounted inside the outer shaft.