JPH0683385U - mechanical pencil - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a mechanical pencil that is easy to manufacture and can prevent core breakage and core clogging. [Structure] A slide bar (8) slidably positioned in front of the chuck (5) and biased toward the chuck (5),
The rear portion is slidably fitted in the through hole of the slide bar (8), and the guide pipe (10) through which the core fed from the chuck (5) passes is separated from the guide pipe (10) in the axial direction in front of the guide pipe. And a slidable tip pipe (12) through which the core passes, a guide pipe (10) and a tip pipe (1
And an elastic body (11) which is located between 2) and contacts the outer periphery of the core that has exited the guide pipe (10) and holds the core.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mechanical pencil, and more particularly to a mechanical pencil capable of preventing core breakage and core clogging.

[0002]

[Prior art]

 As a conventional mechanical pencil having a structure for protecting the core, there is, for example, the one described in Japanese Utility Model Application Laid-Open No. 57-162884. This mechanical pencil is provided with a core protection tube and a sliding tube inside the tip tool, and they are slidably fitted to each other so that the core from the chuck to the tip of the tip tool slides on the core protection tube. Protected by moving tube.

[0003]

[Problems to be solved by the device]

 However, in such a conventional configuration, since the core holding member made of an elastic body that holds the core has to be mounted inside the core protection tube, the mounting is difficult and the manufacturing becomes complicated. The present invention has been made in view of the above problems, and an object of the present invention is to provide a mechanical pencil that is easy to manufacture and that can prevent core breakage and core clogging.

[0004]

[Means for Solving the Problems]

 To achieve the above object, in the present invention, a tip tool fixed to the tip of an outer shaft, a chuck slidable in a through hole in the tip tool and biased backward, and a head of the chuck. In a mechanical pencil that has a chuck ring that fits around the outer periphery and tightens the chuck, and in which the lead is extended as the chuck moves forward, a slide bar that is slidably positioned in front of the chuck and is biased toward the chuck; A guide pipe whose rear part is slidably fitted in the through hole of the bar and through which the core fed from the chuck passes, and a slidable tip pipe which is axially separated in front of the guide pipe and through which the core passes. And an elastic body which is located between the guide pipe and the tip pipe and which contacts the outer periphery of the core exiting the guide pipe and holds the core.

The elastic body may be fixed to the guide pipe or the tip pipe, and may extend radially to the inner circumference of the through hole of the tip and contact the inner circumference. In addition to the elastic body, an elastic body fixed to the guide pipe or the tip pipe and contacting the inner circumference of the through hole of the tip may be provided. It is also possible to further provide a slider that is fixed to the rear portion of the tip pipe and is slidable in the through hole of the tip tool, and fix the elastic body to the slider.

Means for restricting the axial movement of the slide bar in the through hole of the tip tool to prevent the slide bar from falling off from the tip tool may be provided in the tip tool.

[0007]

[Action]

 The guide pipe, the tip pipe, and the slide bar protect the core fed from the chuck, so that the occurrence of core breakage and core clogging can be reduced. Further, since the elastic body for holding the core is positioned between the guide pipe and the tip pipe, its manufacture and assembly are facilitated.

Further, when the elastic body fixed to the guide pipe or the tip pipe comes into contact with the inner circumference of the through hole of the tip tool, the friction force generated by the contact causes the scraping of the pipe when knocking the mechanical pencil. (Return) can be prevented.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a main part of a sharpening pencil according to a first embodiment of the present invention when the lead is stored, FIG. 2 is a knocking diagram, and FIG. 3 is a partial vertical sectional view of the main part when writing. Represent Reference numeral 1 denotes an outer shaft. An inner shaft 2 is concentrically housed in the outer shaft 1, and a tip 3 is screwed to the tip of the inner shaft 2. Usually, this screw is hard and it is desirable that it is not easily removed by the user. Not only when the tip 3 is indirectly fixed to the outer shaft 1 as in this example, the inner shaft 2 can be omitted, and the tip 3 may be directly fixed to the outer shaft 1. Further, the tip tool 3 may be fixed integrally with the outer shaft 1.

In the inside of the front tool 3, through holes 4 having diameters of six sizes are formed in a stepwise continuous manner from the rear end in the axial direction. A chuck 5 is slidably placed in the through hole 4, and its rear part is connected to a lead tank (not shown). Further, a chuck ring 6 is fitted around the outer circumference of the head of the chuck 5 to tighten the chuck 5, and the chuck spring 7 behind the chuck 5 urges the chuck 5 rearward to form a known core feeding mechanism. is doing.

A slide bar 8 is slidably positioned in front of the chuck 5 with respect to the tip tool 3, and a flange 8 a formed on the outer periphery of the rear portion of the slide bar 8 and a step inside the tip tool 3. A slide spring 9 is inserted between and to urge the slide bar 8 rearward toward the chuck 5. The rear portion of the guide pipe 10 is slidably fitted to the slide bar 8 in the through hole in the slide bar 8, and the core fed from the chuck 5 passes through the guide pipe 10. can do. The tip of the guide pipe 10 is press-fitted into the rubber packing 11 which is an elastic body, and the two slide together. The inner circumference of the rubber packing 11 is in contact with the core coming out of the guide pipe 10, and the outer circumference of the rear end of the rubber packing 11 is in contact with the inner circumference of the tip tool 3 to give a friction resistance to both. . A tip pipe 12 is positioned axially forward of the rubber packing 11 so as to be slidable with respect to the tip tool 3 and projectable from a tip opening of the tip tool 3. A slider 13 is fixed to the outer periphery of the rear portion of the tip pipe 12. As shown in the figure, the inner hole of the slider 13 is shaped so that the front part of the rubber packing 11 can be fitted therein, and the tip pipe 12 and the guide pipe 10 are formed by the frictional force generated by the fitting of the slider 13 and the rubber packing 11. Can move integrally while being axially separated. Reference numeral 14 is a ring press-fitted into a hole inside the tip tool 3, and the flange 8 a of the slide bar 8 abuts against the ring 14 to restrict the axial movement of the slide bar 8 so that the front side of the slide bar 8 is prevented. It functions as a stopper to prevent the parts located at the position from falling off backward.

In the mechanical pencil configured as described above, when the knock portion of the mechanical pencil (not shown) is pushed forward in the axial direction, the chuck 5 moves forward against the force of the chuck spring 7 as shown in FIG. The fitting from the chuck ring 6 is released, and the nipping of the lead is released. When the chuck 5 advances, it pushes the slide bar 8 forward against the slide spring 9, and when the slide bar 8 further advances, it pushes the rubber packing 11, the guide pipe 10, the slider 13 and the tip pipe 12, At the maximum, the slider 13 is moved forward until it comes into contact with the stepped portion of the tip 3. As a result, the tip pipe 12 projects from the tip opening of the tip 3 as the lead advances. When the knock is released, the chuck 5 and the slide bar 8 are returned to their original positions by the restoring force of the chuck spring 7 and the slide spring 9, and the chuck 5 holds the lead. On the other hand, the slider 13, the tip pipe 12, and the guide pipe 10 remain in the forward position due to the rubber packing 11 holding the core, and are ready for writing in FIG. After the completion of writing, knocking again and pushing the lead and the tip pipe 12 rearward return to the state of FIG.

During this operation, the lead fed from the chuck 5 is always guided by the guide pipe 10 in the slide bar 8 and then in the leading end pipe 12, so that the lead is protected and broken. The risk of core clogging is reduced. Further, the rubber packing 11 holds the core by frictional force generated between the rubber packing 11 and the core and the inner circumference of the tip tool 3, and also prevents the pipe from returning (shaking) at the time of knocking.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, an elastic member that contacts the core to hold the core and an elastic member that contacts the inner circumference of the tip 3 are separate members. It is composed. The pipe fixing member 15 is fixed to the front end of the guide pipe 10, the tip of the pipe fixing member 15 is fitted into the inner hole of the slider 13, and an annular rubber packing 16 is provided between the pipe fixing member 15 and the slider 13. Deploy. On the other hand, a flange 15a is formed on the rear portion of the pipe fixing member 15, and an O-ring 17 is fitted and fixed between the flange 15a and the slider 13. The rubber packing 16 comes into contact with the core, and the O-ring 17 generates a frictional force between the O-ring 17 and the inner circumference of the tip 3 to hold the core and prevent the pipe from returning.

FIG. 5 shows a third embodiment of the present invention, FIG. 5 (A) is a partial vertical cross-sectional view of the main part, and FIG. 5 (B) is a cross-sectional view taken along the line AA ′ of (A). . In this embodiment, a plurality of through holes (two in the figure) are provided on the outer circumference of the slider 20, the rubber packing 21 is inserted into the slider 20, and a part of the outer circumference of the rubber packing 21 projects outward from the through hole. To do. The inside of the rubber packing 21 comes into contact with the core, and the portion protruding from the through hole generates a frictional force with the inner circumference of the tip tool 3 to hold the core and prevent the pipe from returning. .

A pipe fixing member 22 is fixed to the front end of the guide pipe 10, and the tip of the pipe fixing member 22 is inserted into the rear portion of the slider 20. In this example, the slider 20 is formed integrally with the tip pipe 12. FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, instead of the ring 14 of FIG. 1, a plurality of burr-shaped projections 25 (three in the drawing) are formed in advance around the through hole of the tip 3 (FIG. 6 (B)). After assembling the parts such as the slide bar 8 in front of the tip 3, the projection 25 is caulked and directed inward in the radial direction (FIG. 6 (C)), and the projection 25 functions as a stopper to remove the parts. Is being prevented.

FIG. 7 shows a fifth embodiment of the present invention. In the present embodiment, the rear end edge of the slide bar 8 is raised to form the annular groove 8b, while the ring 26 is press-fitted and fixed in the through hole of the tip tool 3 in front of the slide bar 8 to fix the slide bar 8. A slide spring 9 is press-fitted and fixed between the annular groove 8b and the ring 26. The ring 26 and the slide spring 9 are press-fitted and fixed to prevent the parts from falling off.

FIG. 8 shows a sixth embodiment of the present invention. In this embodiment, the slide spring 9 is press-fitted and fixed between the rear end flange 8c of the slide bar 8 and the stepped portion of the through hole of the tip 3 to prevent the parts from falling off.

[0019]

[Effect of device]

 As described above, according to the present invention, the guide pipe, the tip pipe, and the slide bar protect the core fed from the chuck, and therefore the occurrence of core breakage and core clogging can be reduced. Further, since the elastic body for holding the core is located between the guide pipe and the tip pipe, there is an effect that the manufacturing and assembling thereof can be facilitated.

Further, when the elastic body fixed to the guide pipe or the tip pipe comes into contact with the inner circumference of the through hole of the tip tool, the friction force generated by the contact causes the scraping of the pipe when knocking the mechanical pencil. It has an unprecedented excellent effect of being able to prevent (return).

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a mechanical pencil according to a first embodiment of the present invention, showing a lead housed therein.

FIG. 2 is a partial vertical cross-sectional view of a main part of the embodiment shown in FIG. 1 when knocked.

FIG. 3 is a partial vertical cross-sectional view of a main part of the embodiment shown in FIG. 1 during writing.

FIG. 4 is a partial vertical cross-sectional view of the essential parts of a second embodiment of a mechanical pencil according to the present invention.

FIG. 5 (A) is a partial vertical cross-sectional view of a main part of a mechanical pencil according to a third embodiment of the present invention, and FIG. 5 (B) is (A).
FIG. 6 is a sectional view taken along line AA ′ of FIG.

FIG. 6A is a partial vertical cross-sectional view of a main part of a mechanical pencil according to a fourth embodiment of the present invention, FIG. 6B is an enlarged view before caulking the protrusion, and FIG. It is an enlarged view after caulking.

FIG. 7 is a partial vertical cross-sectional view of the essential parts of a mechanical pencil according to a fifth embodiment of the present invention.

FIG. 8 is a partial vertical cross-sectional view of the essential parts of a sixth embodiment of a mechanical pencil according to the present invention.

[Explanation of symbols]

 1 Outer Shaft 3 Tip Tool 5 Chuck 6 Chuck Ring 8 Slide Bar 10 Guide Pipe 12 Tip Pipe 11, 16, 21 Elastic Body 17 Elastic Body 20 Slider 14, 25, 26, 8b, 8c Fall-out Prevention Means

Claims (5)

[Scope of utility model registration request] 1. A tip (3) fixed to the tip of an outer shaft (1), and a chuck (5) slidable in a through hole in the tip (3) and biased backward. A mechanical pencil having a chuck ring (6) fitted around the outer circumference of the head of the chuck (5) and tightening the chuck, and sliding the lead in front of the chuck (5) in a mechanical pencil in which the lead is fed out by the forward movement of the chuck (5). A slide bar (8) that is positioned so as to be urged toward the chuck (5) and a rear part that is slidably fitted in a through hole of the slide bar (8) and is extended from the chuck (5). And a guide pipe (10) through which the core passes, and a slidable tip pipe (12) axially separated in front of the guide pipe (10) and through which a core passes.
And an elastic body (11, 16, 21) which is located between the guide pipe (10) and the tip pipe (12) and which holds the core by coming into contact with the outer periphery of the core exiting the guide pipe (10). A mechanical pencil that is characterized. 2. The elastic body (11) is a guide pipe (1).
0) or the tip pipe (12), and also extends radially to the inner circumference of the through hole of the tip tool (3) and contacts the inner circumference. Pencil. 3. An elastic body (17) fixed to the guide pipe (10) or the tip pipe (12) and contacting the inner circumference of the through hole of the tip tool (3) is provided separately from the elastic body (16). The mechanical pencil according to claim 1, wherein: 4. A slider (2) fixed to the rear portion of the tip pipe (12) and slidable in the through hole of the tip tool (3).
0) is further provided, and the elastic body (21) is fixed to the slider (20). 5. Means (14, 25, 26) for preventing axial displacement of the slide bar (8) in the through hole of the tip tool (3) to prevent the slide bar (8) from falling off the tip tool (3). , 8b, 8
2. C) is provided in the tip (3).
A mechanical pencil as described in Nos. 4 to 4.