JP2606468Y2 - Opening / closing device for core cartridge - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opening / closing device for a lead cartridge of a cassette type mechanical pencil.

Recently, for example, as shown in FIG.
Storing the entire lead cartridge 101 containing 104 ;
There has been provided a so-called cassette type mechanical pencil which eliminates the need for refilling each lead and replaces the lead and refills the lead without soiling the hands. The lead cartridge 101 of the conventional cassette type mechanical pencil only has the cap 102 fitted on the tip, and when exchanging the lead of the mechanical pencil or refilling the lead, first, the tip cap 10 is used.
2 was discarded and discarded, and fitted in the outer cylinder 103 of the mechanical pencil with the tip of the lead cartridge opened as shown in FIG .

Therefore, if the lead cartridge 101 is slightly lowered after the tip cap 102 is removed, there is a problem that the lead 104 jumps out of the lead cartridge 101. Therefore, at the time of replacement of the lead, it is necessary to always fit the lead cartridge 101 into the outer cylinder 103 while noticing while holding the lead cartridge 101 upward. Also, when the lead cartridge 101 is detached from the outer cylinder 103, there is a problem that if the lead cartridge 101 is slightly directed downward, the lead 104 jumps out of the lead cartridge 101 and remains in the outer cylinder 103. .

On the other hand, in the conventional one, as shown in FIG. 18, a lead cartridge 101 containing a large number of leads 104,
Since the lead guide 105 for detachably fitting the lead cartridge 101 is housed in the outer cylinder 103,
In order to pick up the remaining core in the outer cylinder 103 with the core cartridge 101, a tapered chamfered portion 107 is required on the inner surface of the tip, and the inner diameter of the outer cylinder 103 is changed to a stepped inner step wall as shown in the figure. It is necessary to provide the portion 106, and there is a problem that the core cartridge 101 is restricted to a small diameter by the inner stepped wall portion 106, and the core storage capacity is reduced. In addition, since the outer cylinder 103 having the above-described stepped wall portion 106 cannot be extruded, it must be injection-molded. In this case, the mold is more expensive than the extrusion molding. There was also.

Accordingly, the present applicant has filed Japanese Patent Application No.
No. 1-204692 (Kokoku No. 6-2438), JitsuganAkira No. 61-199672 (real fairness No. 5-13595), JitsuganAkira No. 61-199673 (real fairness No. 5-13596)
The above problem has been solved by a lead cartridge opening / closing device. The lead cartridge opening / closing device according to the prior application includes a chuck-type opening / closing mechanism that has an elastic opening / closing part radially divided along an axis and is mounted on a tip of the lead cartridge. When the outward engaging pieces protruding in the opposite direction radially outward at the respective distal ends are press-fit into the lead guide, the elastic opening and closing of the elastic engaging pieces is performed against the inward elastic force of the elastic engaging pieces. A radially-divided core conduction hole formed at the tip axis portion of one end is opened in an expanded state, and
When the lead cartridge is pulled out from the lead guide, the press-fitting engagement is released, and the lead conduction hole is closed in a concentric reduced diameter state by the elastic restoring force of the elastic opening / closing piece.

In such a cartridge opening / closing device of the prior application, if the chuck-type opening / closing mechanism is a new product immediately after molding,
When the lead is pulled out from the lead guide because the elastic force of the elastic opening / closing portion is sufficient, the core conduction hole is securely closed by the elastic restoring force of the elastic opening / closing portion, but the chuck type opening / closing mechanism is inserted into the lead guide. If left unattended for a long period of time, the elastic opening / closing piece deforms in a familiar manner with the core conduction hole opened, so that the elastic force of the elastic opening / closing piece deteriorates with time.

Therefore, as described above, the elastic opening / closing piece that has been left for a long time while being press-fitted and engaged in the lead guide has a reduced force for closing the core conduction hole due to deterioration of elasticity due to aging. When the lead cartridge is pulled out from the lead guide, the lead conduction hole is closed.However, when the pulled lead cartridge is shaken for confirmation of the lead, the closing force of the lead conduction hole is weakened as described above. Due to the load of the lead and the vibration, the lead conduction hole may be opened and the lead inside may be popped out.

[0008] also been made in order to solve this problem
Is the Japanese application No. 62-145439 (Jitsuhei 6-38713)
Publication) discloses an opening / closing device for a lead cartridge.
In this lead cartridge opening and closing device, a lead conduction hole of a chuck type opening / closing device provided in a lead cartridge which is removably fitted to a mechanical pencil and refills and replaces a lead is formed in a radial direction. The radial center point of each of the divided core conduction holes is displaced so that the core conduction holes communicate with each other in a stepped shape when the core conduction hole is closed in the displaced state, and when the core cartridge is pulled out from the lead guide. Regardless of the deterioration of the elastic force due to the aging of the elastic opening / closing piece of the chuck-type opening / closing mechanism, the core conduction hole can be reliably closed to the specified size. There is no such thing that the wick of the heart jumps out unnecessarily.

[0009]

Since the conventional opening / closing device for a lead cartridge has been constructed as described above, when the lead cartridge is pulled out from the lead guide, the half-core conduction hole is formed by the elastic restoring force of the elastic opening / closing piece. Is closed in a concentric reduced diameter state to prevent the core from jumping out, and furthermore, the radial center point of the half-core conductive hole is displaced and closed in a stepwise manner, so that the elastic opening and closing Even if it becomes impossible to obtain a complete closure due to the deterioration of the resilience due to the change, it is possible to prevent the lead from popping out.

[0010] However, the above-mentioned configuration in which the half-core conducting hole is closed in a position shifted by the elasticity of the elastic opening / closing piece portion is not reliably positioned, so that even a small external force is likely to cause a lateral slip, and particularly in the case of a fine core, Easily penetrates easily.

The present invention has been made to solve the above-described problem, and has as its object to provide a configuration in which the position of the half-core conductive hole can be reliably shifted when the elastic opening / closing piece is closed. .

[0012]

SUMMARY OF THE INVENTION A lead cartridge opening / closing device according to the present invention has a half-core lead hole divided radially.
An elastic opening / closing piece having:
Engagement with the lead guide and engagement from the lead guide
When released, elastically move diametrically inward and outward,
An outwardly engaging piece for opening and closing the split core conductive hole, and the elastic opening and closing piece
Notch provided in the portion, wherein the outward engagement piece portion slides in contact therewith.
Part and the notch part where the outward engagement piece part slides and contacts.
When the elastic opening / closing piece is elastically restored
The center point of the half-core conduction hole is shifted
And a projection for closing the half-core conduction hole in the state.
are doing.

[0013]

According to the lead cartridge opening / closing device of this invention, when the chuck type opening / closing mechanism is disengaged from the lead guide and closed, the center point of the half-core conduction hole is located on the sliding surface of the notch. The projections provided ensure that the misaligned step is maintained, thereby preventing the lead housed in the lead cartridge from jumping out.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1 , reference numeral 1 denotes an outer cylinder of a mechanical pencil, 2 denotes a leading tool screwed to the tip of the outer cylinder 1, and 3 denotes a part of a center feeding mechanism arranged in the outer cylinder 1. 4 has a lead chuck 5 for biting the lead 4, and a lead guide 6 is fitted to the rear end of the lead chuck 5. Here, it goes without saying that a chuck joint between the lead chuck 5 and the lead guide 6 may be added to the design.

The lead guide 6 has a function of sending out the core 4 one by one to the lead chuck 5, and as shown in FIGS. 2 and 3, a front fitting in which the rear end of the lead chuck 5 is fitted. and Goana 60, the core feed hole 61 having an inner diameter that can feed the core 4 only one continuous with the front fitting hole 60, the rear end portion larger diameter section difference shaped chuck housing connecting to the core feed hole 61 It has a hole 62 and a large-diameter stepped rear fitting hole 63 which is connected to the rear end portion and into which the core cartridge 7 is removably fitted. In addition, a number of ribs (not shown) are provided on the inner peripheral wall portion of the rear fitting hole 63 so as to project smoothly from the core cartridge 7.

A lead cartridge 6 is detachably fitted and connected to the lead guide 6 via a chuck type opening / closing mechanism 8. The chuck-type opening / closing mechanism 8 of the first embodiment is connected to the leading end of the core cartridge 7 by fitting and engaging the rear cylindrical portion 80 into the core cartridge 7.

At the front end of the rear cylindrical portion 80, a small-diameter stepped front cylindrical portion 82 is coaxially and integrally provided. As shown in FIGS. 2, 3, 6, and 7, the front cylindrical portion 82 has an axial slit 83 extending from a substantially middle portion to a front end.
The elastic opening / closing piece 84 divided into two parts in the diameter direction
a and 84b are integrally formed. These elastic opening / closing pieces 84a and 84b have an inward elastic force and can be expanded and contracted in the diameter direction. Arc-shaped half-core conduction holes 85a and 85b are provided. At the front ends of the half-core conductive holes 85a, 85b, as shown in FIGS. 2, 3, 6, and 9, half front tapered holes 86a, 86b whose front ends are gradually larger in diameter. Is formed.

Further, at the rear ends of the half-core conducting holes 85a and 85b, there are formed half rear tapered holes 87a and 87b each having a gradually increasing diameter on the rear end side thereof. And
Outward engaging pieces 88 projecting radially outward on opposite sides of the elastic opening / closing pieces 84a and 84b are provided on the opposite sides.
a and 88b are integrally formed, and the elastic
4a, 84b the outwardly engaging pieces 88a, 88b
On the other side of the notch , as shown in FIGS.
9a and 89b are provided.

The outward engaging piece 88a of one elastic opening / closing piece 84a is connected to the notch 8 of the other elastic opening / closing piece 84b.
9b and the outward engaging piece 88b of the other elastic opening / closing piece 84b is slidably fitted into the cutout 89a of the one elastic opening / closing piece 84a. The portions 88a and 88b are alternately projected outward from the outer peripheral surfaces of the resilient opening and closing pieces 84a and 84b on the other side. Here, the outward engagement piece portion 88a, 88b, as shown in FIG.
As shown in FIGS. 2 and 5, the lengths (a) and (b) from the respective axial centers are formed longer than the radius (c) of the chuck housing hole 62.

As shown in FIG. 2 and FIG. 6, a forward arcuate surface 9 is provided on the front of each outward engaging piece 88a, 88b.
0a, 90b are formed, and these forward arc surfaces 90a, 90b are formed.
90b allows the elastic opening / closing pieces 84a and 84b to be easily pressed into the chuck housing holes 62 of the lead guide 6 . Here, each of the notches 89a,
As shown in FIGS. 4, 5 and 9, the inner edge of each of the inner surfaces 89b has a sliding surface 9 with the mating outwardly engaging pieces 88b , 88a fitted in the notches 89a, 89b.
1a, 91b, these sliding surfaces 91a, 9
1b is provided with projections 92a, 92b for maintaining a gap with the outward engagement pieces 88b, 88a on the other side.

[0021] These projections 92a, thus to 92b, outward engagement piece portion 88b, 88a and the sliding surface 91a, 91b
4 and FIG.
As shown in FIG. 7 , at the time of closing, the half-core conduction holes 85a, 85b
Are maintained in such a state that their respective radial center points are displaced by a width corresponding to the gaps 93a, 93b in the tangential direction of the inner joint surfaces of the elastic opening / closing pieces 84a, 84b. As a result, the half-core conduction holes 85a and 85b communicate with each other in a stepwise manner when closed, so that their substantial closed diameter is smaller than the diameter of the core 4 having the minimum diameter.

Further, the half-core conduction holes 88a, 88b
When the elastic opening / closing pieces 84a, 84b are elastically deformed in the radially expanding direction, outwardly engaging pieces 88a, 88 to be described later are used.
5 and the chuck housing hole 62,
As shown in the figure, the opening is made in an expanded state.
The outward engagement piece portion 88a, 88b is engaged bullet adhesive engagement with the chuck housing hole 62, thereby, lead cartridge 7 is set plugged into the lead guide 6 through the chuck type opening and closing mechanism 8.

Further, as shown in FIGS. 6, 7 and 9, on the outer peripheral surfaces of the elastic opening / closing pieces 84a and 84b, undercuts 94a and 94b having a semicircular cross section are provided across both. I have. Due to the recesses 94a and 94b, the elastic opening / closing pieces 84a and 84b are formed to be thin in the diameter direction and to be easily elastically deformed.
When the elastic opening and closing pieces 84a and 84b are pulled out from
The elastic opening / closing pieces 84a and 84b are easily returned to the original state by the elastic restoring force, so that the elastic engagement with the chuck housing hole 62 and the disengagement thereof are performed smoothly and reliably. still,
The undercuts 94a and 94b are not inevitable elements.

Next, the operation will be described. When replacing the lead or checking the lead in the middle, etc., the lead cartridge 7 fitted to the lead guide 6 is removed together with the chuck-type opening / closing mechanism 8. At this time, the outward engagement pieces 88a, 88b of the chuck type opening / closing mechanism 8 are released from the elastic engagement with the chuck accommodating holes 62, so that the elastic opening / closing pieces 84a, 84b respectively become inward of their own. The elastic force (elastic restoring force) elastically deforms in the diameter reducing direction and the half-core conducting holes 85a and 85b automatically close to each other so that the core 4 cannot conduct.

At this time, the half-core conduction holes 85a, 85
As shown in FIG. 4, b is securely closed in a stepped manner at intervals 93a and 93b corresponding to the heights of the projections 92a and 92b , so that the diameter of the substantially closed hole with respect to the core 4 having the smallest diameter is further reduced. For this reason, when the core cartridge 7 is removed, the core 4 in the core cartridge 7 comes out of its distal end opening and remains in the outer cylinder 1 or spills out of the outer cylinder 1. Due to the load and vibration of the inner core when shaking to check the core, etc.
There is no danger of jumping out.

Furthermore, since there is no risk of residual cores being generated, it is not necessary to provide a chamfered portion such as a taper on the inner surface of the leading end of the lead cartridge 7. There is no manufacturing problem of becoming insufficient. Further, unlike the related art, it is not necessary to provide the inner step portion in the outer cylinder 1, so that the outer cylinder 1 can be formed by inexpensive extrusion molding, and the diameter of the core cartridge 7 can be increased. The core storage capacity can be dramatically increased.

Further, when the core 4 remains over the core feed hole 61 of the lead guide 6 and the half-core conduction holes 85a and 85b of the chuck type opening / closing mechanism 8, the remaining core 4 is When the outward engagement pieces 88a, 88b are released from the elastic engagement when the opening / closing mechanism 8 is removed, the elastic opening / closing pieces 84 are released.
a and 84b are elastically deformed in the diameter-reducing direction, and the half-core conduction holes 85a and 85b are closed stepwise.
Sufficient centering force is obtained by the half-core conducting holes 85a and 85b, so that the elastic opening and closing pieces 84a and 84b reliably chuck and remove the pieces.

Therefore, after the core cartridge 7 is removed,
If the lead 4 is pulled out from the half lead-through holes 85a, 85b or pushed into the lead cartridge 7, the remaining lead 4 may be broken when the lead cartridge 7 is replaced. There is no possibility that the lead 4 may be clogged by the lead 4.

Then, the new lead cartridge 7 is inserted into the outer cylinder 1.
Of the chuck type opening / closing mechanism 8, the outward engagement pieces 88 a and 88 b of the chuck type opening / closing mechanism 8 are stored in the lead guide 6.
It is press-fitted into the hole 62 and elastically engages, whereby the half-core conduction holes 85a and 85b of the chuck-type opening / closing mechanism 8 are opened as described above. Can be supplied.

At the time of such replacement of the lead cartridge 7, the outward engaging pieces 88a and 88b are
2 until they are inserted into the second half.
Since b is closed in the form of a small-diameter step, there is no danger that the core 4 in the core cartridge 7 will jump out as in the conventional case. In addition, since there is no need for a mechanical pencil by inverted upside down to exchange work while maintaining the lead cartridge 7 upward, intends simply and easily handily line the exchange work of the lead cartridge 7 regardless of the orientation of the mechanical pencil With
I can . That is, in the chuck type opening / closing mechanism 8, the degree of opening / closing of the elastic opening / closing pieces 84a, 84b is reliably adjusted by the outwardly engaging pieces 88a, 88b and the projections 92a, 92b . The core 4 having a diameter can also be used.

FIGS. 10 to 16 show a chuck type opening / closing mechanism 8 according to a second embodiment. The chuck-type opening / closing mechanism 8 of the second embodiment has a configuration in which the whole is divided into two parts in the diameter direction along the axis. That is, the rear cylindrical portion 80 has a half cylindrical portion 801a,
801b. These half cylindrical portions 801
When pressed into the rear end of the core cartridge 7 shown in FIG. 1 to FIG. 3 , the members a and 801 b are combined and concentrically combined, and when they are combined together, they are securely engaged and fixed. I have.

FIGS. 10, 12, and FIG.
13, as shown in FIG. 15, the half cylindrical portion 801a,
An engagement projection 802a and an engagement recess 803a are provided on one side of the mating surface of the engagement projection 801b, and the engagement projection 802a is provided on the other side.
And the above-described engaging recess 803
The engagement protrusions 802b corresponding to a are integrally formed.

Here, the engaging projections 802a, 802b
1 and FIG. 1 and FIG.
3, as shown in FIG.
01b are formed to be long in the respective axial directions. Then, the engaging recesses 803a, 803b
An engagement rib 804a, 804b is integrally protruded from the inner peripheral surface of the boss, and the engagement rib 804a, 804b is engaged with the outer peripheral surface of the engagement convex portion 802a, 802b. Grooves 805a and 805b are provided.

Accordingly, the engaging convex portion 802a and the engaging concave portion 803a of one half cylindrical portion 801a are connected to the other half cylindrical portion 8a.
When the engagement ribs 804a, 804b and the engagement grooves 805a, 805b are engaged with the engagement concave portions 802b and the engagement convex portions 803b, respectively, the two half cylindrical portions 801a, 801b are engaged. They are correctly combined and combined without any displacement in the axial direction. For this reason,
The engaging projections 802a and 802b are
a and 803b, the half cylindrical portions 801a and 801b can be joined together more firmly when they are combined, and the assembling accuracy of the chuck-type opening / closing mechanism 8 is further improved. 7 can be easily and reliably set, and the elastic opening / closing pieces 84a, 84b described later can be smoothly and reliably opened and closed.

Further, the half cylindrical portions 801a, 801b
As shown in FIGS. 12 and 14, wide engaging projections 806a and 806b having a semicircular cross section
If, pointed engagement ribs 807a, 807b are one body projecting. Then, the half cylindrical portions 801a, 801b
Are combined and fitted in the core cartridge 7, the wide engaging projection 8 is formed on the inner peripheral surface of the core cartridge 7.
06a, 806b and the engaging ribs 807a, 807b are in pressure contact engagement with each other.
By 6a and 806b, a sufficient fitting pressure with the inner peripheral surface of the core cartridge 7 can be obtained.

Therefore, the chuck type opening / closing mechanism 8 can be fitted and connected stably with the sufficient fitting pressure. At the tips of the half-cylindrical portions 801a, 801b, elastic opening / closing pieces 84a, 84b are integrally connected. These elastic opening and closing pieces 84a and 84b show one of them .
13 as in, in advance by plastic deformation (elastic deformation) in the radially inward by Θ corner. Accordingly, the elastic opening / closing piece 84
At the time of combining and combining the a and 84b, the elastic opening and closing piece portions 84a and 84b can be combined and combined with no gap by strongly pressing them.

For this reason, the elastic opening / closing pieces 84a, 84
10b, and outwardly engaging piece 88 extending to the diametrically opposite side as shown in FIG . 10 and FIG.
a, 88b, as shown in FIGS. 1 to 3, when pressed into the lead guide 6, the projections 92a, the resilient closing piece portions 84a provided with 92b, notch 89a of 84b, the inside 89b it
The sliding surfaces 91a and 91b slide along the sliding surfaces 91a and 91b, and their outward engaging pieces 88a and 88b move in the relative direction (diameter outside).
And the elastic opening and closing pieces 84a and 84b move outward in the diametrical direction integrally with the outwardly engaging pieces 88a and 88b, so that the half-core conducting holes 85a and 85b are the same as in the previous embodiment. Open to the state.

In this state, when the outward engaging pieces 88a, 88b are pulled out from the lead guide 6, the elastic opening / closing pieces 84a, 84b are elastically restored inward in the diametrical direction, so that the half-core conducting holes are formed. 85a and 85b are the sliding surfaces 9 of the notches 89a and 89b as in the case of the previous embodiment.
1a, the projections 92a provided on the 91b, displaced laterally by the width corresponding to the height of the 92b to closed in uneven diameter reduction state. As described above, by the press-fitting of the outward engaging pieces 88a, 88b into the lead guide 6 and withdrawing from the lead guide 6, the elastic opening / closing pieces 84a, 84b are connected to the half-core conductive holes 85a, 85b. Although the opening and closing operation is performed, as described above, by dividing the entire chuck-type opening and closing mechanism 8 into two, the opening and closing operation radius of the elastic opening and closing pieces 84a and 84b increases, and the elastic opening and closing pieces 84a and 84b. 84b
Is easily elastically deformed.

Moreover, the elastic opening / closing pieces 84a, 84b
As described above, since each has a sufficient elastic restoring force due to being plastically deformed inward in the radial direction in advance, it smoothly opens and closes, and the degree of fatigue is reduced by repeating the opening and closing operations.
Also, by the whole of the chuck type opening and closing mechanism 8 into two split, the elastic closing piece portions 84a, 84b the outward engagement piece portion 88a at the tip end of, 88b and half core through hole 85a, 85b of the As shown in FIG. 11 , the formed portion can be easily divided and formed in a stepped diameter direction.

Accordingly, the chuck type opening / closing mechanism 8 can be easily formed, and the elastic opening / closing pieces 84a, 84b can be formed.
By the sufficient elastic restoring force of the above, the half-core conductive holes 85a,
The mating surfaces of the cores 85b can be securely joined without any gaps, and there is no possibility that the cores 4 in the elastic opening / closing pieces 84a and 84b and the core cartridge 7 will fall out and fall.

[0041]

As described above, according to the present invention, when the lead cartridge is press-fitted into the lead guide, the chuck-type opening / closing mechanism is guided in the centripetal direction on the inner peripheral surface of the lead guide, and the diameter is increased. By elastically deforming, the core conduction hole is opened to a specified size and a state in which smooth conduction of the cores of different diameters is possible, and the outward engagement piece and the notch formed integrally with the elastic opening and closing piece. Since the projections are provided on the sliding surfaces of the notches that are in contact with each other, when the press-fitting engagement is released, the chuck-type opening / closing mechanism is elastically restored in the radially reduced direction by the inward elastic force, and the core conduction is performed. The holes are closed, and in the closed state, the respective radial center points of the core conduction holes are in communication with each other in a state in which they are laterally displaced by a width corresponding to the height of the projection, and thereby the core conduction holes are in communication with each other. Are stepped with each other, so that the core conduction hole is closed. Is substantially reduced in diameter, so that the core conduction hole is maintained in a securely closed state in which the core does not pop out regardless of the elasticity of the elastic opening / closing mechanism of the chuck type opening / closing mechanism irrespective of deterioration over time. it can. For this reason, even if the lead cartridge pulled out from the lead guide is shaken for lead confirmation or the like, the lead in the lead does not jump out due to the load or vibration of the lead.

In particular, in the present invention, even when a plurality of cores of different diameters are used, the opening and closing stroke of the chuck-type opening / closing mechanism may be small. It is possible to make conduction impossible, and to make the core having the maximum diameter conductive when the core conduction hole is opened.
That is, in the case of sharing the cores of different diameters, the core with the minimum diameter cannot be conducted when the core conduction hole is closed, and the core with the maximum diameter must be conducted when the core conduction hole is opened. If the hole diameter is formed smaller than the minimum core diameter, and it is opened larger than the maximum core diameter at the time of opening, the opening / closing stroke of the chuck-type opening / closing mechanism increases, and excessive stress is generated in the chuck-type opening / closing mechanism. Therefore, it is difficult for the chuck-type opening / closing mechanism to return to the original closed state.

However, according to the present invention, the provision of the projection causes the respective radial center points to be displaced when the core conduction hole is closed, and the positional deviation causes the core diameter of the core conduction hole to be minimized when the core conduction hole is closed. Since the diameter becomes smaller than the diameter, there is no need to make the hole diameter of the core conduction hole itself smaller than necessary than the minimum diameter core diameter. Since the opening / closing stroke can be reduced, the chuck-type opening / closing mechanism does not generate excessive stress, and the chuck-type opening / closing mechanism can always be smoothly and reliably opened / closed. By pulling it out from the lead guide to the lead cartridge,
The core conduction hole is closed to a state substantially smaller than the minimum diameter of the core, and the closed state is pulled out by being surely maintained irrespective of the deterioration of the resilience due to the aging as described above. Even if the lead cartridge is shaken to check the lead, the lead inside will not jump out, and when the lead cartridge is inserted into the lead guide, the state where the lead with the largest diameter can be conducted will be in the above lead conduction state. Various design advantages are obtained such that the holes open smoothly.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a cassette type mechanical pencil according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the mechanical pencil before assembly of a core cartridge mounting part.

FIG. 3 is a sectional view after the assembly.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a side view of the chuck-type opening / closing mechanism according to the first embodiment.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a sectional view taken along line IX-IX of FIG. 6;

FIG. 10 is a side view of a state where the chuck-type opening / closing mechanism according to the second embodiment is combined and combined.

FIG. 11 is a left end view of FIG. 10;

FIG. 12 is a sectional view taken along line AA of FIG. 10;

FIG. 13 is a side view showing one chuck type opening / closing mechanism of FIG. 10;

FIG. 14 is a sectional view taken along line BB of FIG.

FIG. 15 is a plan view of FIG.

16 is a sectional view taken along line CC of FIG.

FIG. 17 is a perspective view of a conventional lead cartridge.

FIG. 18 is a longitudinal sectional view of a conventional mechanical pencil of this type.

Claims (1)

(57) [Scope of request for utility model registration] 1. A lead cartridge opening / closing device which is detachably fitted to a mechanical pencil and refills / replaces a lead.
Therefore, the elastic opening having the half-core conduction hole divided in the radial direction
A lead guide provided on the closing piece and the elastic opening / closing piece;
Engagement with the lead guide and release from the lead guide.
Open and close the half-core conduction hole by elastically moving inward and outward
An outward engaging piece portion, and an elastic opening / closing piece portion,
A notch portion with which the outwardly engaging piece slides in contact with the outwardly engaging piece;
The mating portion is provided on the surface of the notch portion which slides and comes into contact with,
When the elastic opening / closing piece portion is elastically restored, the half-core conduction occurs.
The half-core is placed in a stepped position with the center point of the hole shifted.
And a projection for closing the conduction hole .