TW201914839A - Mechanical pencil capable of preventing a pencil lead from being broken when an impact is applied to a mechanical pencil from the outside - Google Patents

Abstract

The present invention provides a mechanical pencil that can prevent a pencil lead from being broken when an impact is applied to a mechanical pencil from the outside. One of the embodiments of the mechanical pencil of the present invention includes: an axle cylinder; a buffer spring whose rear end is supported by the axle cylinder; and a sleeve, at the state of being elastically supported by the buffer spring applying pressure elastically forward in the axial direction, capable of moving in a direction orthogonal to the axial direction due to the impact applied from the outer side of the axle cylinder; a clamping head spring having a front end supported by the sleeve; a clamping head for holding the pencil lead; a pencil lead tube engaged with the clamping head and elastically pressed backward in the axial direction by the clamping head spring together with the clamping head; and a contact sliding part for suppressing the said sleeve to move in a direction orthogonal to the said axial direction.

Description

 mechanical pencil  

The present invention relates to a mechanical pencil having a collet for holding a refill, which can be output by a pressing operation.

Conventionally, there has been disclosed a mechanical pencil in which a chuck mechanism having a collet and capable of outputting a refill by a pressing operation is housed in a substantially cylindrical sleeve and held in a barrel. For example, the mechanical pencil disclosed in Patent Document 1 has a buffer spring disposed behind the sleeve. The sleeve is elastically biased forward in the axial direction by the buffer spring. In this way, when the mechanical pencil is being written, if an excessive writing pressure is applied to the refill, the sleeve will move rearward in the axial direction against the elastic pressing force of the buffer spring. This can reduce the core break of the pen when writing.

 Prior technical literature    Patent literature  

[Patent Document 1] Japanese Patent Laid-Open Publication No. SHO-50-138932 (please refer to, for example, the first right column on the second page, lines 1 to 8, and the third page on the left column, lines 16 to 18, etc.).

The mechanical pencil disclosed in Patent Document 1 can prevent the core of the core from being broken due to an excessive writing pressure at the time of writing. However, when the automatic pencil is dropped or the like is applied to the automatic pencil from the outside, the core is broken. Therefore, it is desirable to provide a mechanical pencil that is resistant to punching.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mechanical pencil which can prevent a core from being broken when an impact is applied to a mechanical pencil from the outside.

One of the states of the mechanical pencil of the present invention comprises: a shaft cylinder; a buffer spring received in the shaft cylinder, and a rear end supported by the shaft cylinder; and a sleeve received in the shaft cylinder, which is opposite to the buffer spring The barrel is elastically biased forward in the axial direction, and is elastically supported by the buffer spring, and is movable in a direction orthogonal to the axial direction by an impact applied from the outer side of the barrel; the chuck spring accommodates The sleeve is supported by the sleeve at the front end; the chuck is received in the shaft cylinder for holding the refill; the refill tube is for receiving the refill received by the shaft cylinder, and the collet is embedded with the collet In conjunction with the chuck, the chuck spring is elastically biased rearward in the axial direction with respect to the sleeve; and the sliding portion is prevented from moving in a direction orthogonal to the axial direction.

According to one aspect of the present invention, it is possible to provide a mechanical pencil which can prevent the core from being broken when an impact is applied to the automatic pencil from the outside.

1‧‧‧Automatic pencil

2‧‧‧ shaft tube

2a‧‧‧ recess

2b‧‧‧ convex

2c‧‧‧Protruding

2d‧‧‧ Male thread

3‧‧‧Handle

3a‧‧‧孔部

4‧‧‧ pen head

4a‧‧‧Inner tube

4a1‧‧‧ ribs

4a2‧‧ Section

4b‧‧‧Outer tube

4b1‧‧‧ female thread

4c‧‧‧ openings

5‧‧‧ Pressing Department

5a‧‧‧ Pressing body

5a1‧‧‧ core insert hole

5b‧‧‧Eraser

5c‧‧‧Press the pen cover

6‧‧‧ tail bolt

7‧‧‧ buckle

20‧‧‧chuck mechanism

21‧‧‧Refill tube

22‧‧‧ chuck

23‧‧‧Clip ring

24‧‧‧Sleeve

24a‧‧‧Protruding

24b‧‧‧Protruding

25‧‧‧buffer spring

26‧‧‧Chuck spring

30‧‧‧ front end tube

31‧‧‧ Guide tube

31a‧‧‧insert feet

31b‧‧‧ base end

32‧‧‧ core holder

32a‧‧‧Slit

36‧‧‧Restoring spring

38‧‧O ring

L‧‧‧ axis

T‧‧‧Refill

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front elevational view showing the appearance of a mechanical pencil according to an embodiment of the present invention.

Fig. 2 is a longitudinal sectional view showing a mechanical pencil according to an embodiment of the present invention.

Fig. 3 is an enlarged longitudinal cross-sectional view showing the middle portion of the mechanical pencil according to the embodiment of the present invention, and the front side portion and the rear side portion are enlarged.

 Form for implementing the invention  

Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 is a view showing the appearance of the mechanical pencil 1. The automatic pencil 1 is a push type mechanical pencil that outputs the refill T by pressing the pressing portion 5. The mechanical pencil 1 has a substantially cylindrical shaft barrel 2. The front side of the barrel 2 can be formed by two-color molding, and includes a recess 2a and a projection 2b formed of a hard primary molding material, and a grip 3 formed of a soft material secondary molding material. The convex portion 2b formed of a hard primary molding material is exposed from a substantially rectangular hole portion 3a extending in the front-rear direction on the grip 3 formed of a soft material secondary molding material. The surface of the grip 3 is substantially flush with the surface of the convex portion 2b. The pen tip 4 is fixed to the front end of the barrel 2. The front end tube 30 can be housed at the front end of the pen tip 4 and protruded, and the refill T can protrude from the front end opening of the front end tube 30.

The rear end portion of the barrel 2 can be inserted into the tail plug 6 and fixed. The pressing portion 5 is disposed at the rear end portion of the tail plug 6. The refill T can be output from the front end opening of the distal end tube 30 by pressing the pressing portion 5. A clip 7 can be attached to the outer peripheral surface of the tail plug 6.

Fig. 2 is a longitudinal sectional view showing the mechanical pencil 1 cut in the longitudinal direction. Fig. 3 is a partially enlarged longitudinal cross-sectional view showing the mechanical pencil 1 cut in the longitudinal direction and showing the front side portion and the rear side portion thereof enlarged. A pen tube 21 extending forward and backward can be accommodated in the barrel 2. The pressing portion 5 is detachably mounted at the rear end of the refill tube 21. The pressing portion 5 has a pressing portion main body 5a that is fitted to the outer peripheral surface of the rear end of the pen core tube 21, an eraser 5b that is held by the pressing portion main body 5a, and a pressing pen cover that is attached to the pressing portion main body 5a by covering the eraser 5b. 5c. When the refill T is to be replenished to the refill tube 21, the pressing pen cover 5c and the eraser 5b are detached from the pressing portion main body 5a. Next, the refill T is replenished into the inside of the refill tube 21 from the rear through the core insertion hole 5a1 formed in the pressing portion main body 5a. The pressing portion 5 is movably moved in the direction of the axis L by being guided by the tail plug 6, and is restricted to be moved in a direction not perpendicular to the direction of the axis L.

The rear end of the collet 22 is fitted to the front end of the refill tube 21 and fixed. At the front end of the chuck 22, three slits are formed at three positions in the circumferential direction, and the three chuck pieces are elastically deformed and restored, respectively, to clamp and release the refill T. A collet ring 23 detachable from the rear is attached to the outer periphery of the front end portion of the collet 22. A substantially cylindrical sleeve 24 is attached to the outer periphery of the front end portion of the collet 22 and the refill tube 21 behind the collet ring 23, and as will be described later in detail, the sleeve 24 is mounted so as to be oriented in the direction of the axis L and the axis. The L direction moves in the direction orthogonal to each other.

As will be described in detail later, the sleeve 24 prevents the punch applied from the outside of the mechanical pencil 1 from being transmitted to the collet 22 and the refill T, and the contact sliding portion absorbs at least a portion of the force of the punch to prevent the refill T from being broken. Therefore, the sleeve 24 does not directly contact the collet 22, and on the other hand, the sleeve 24 and the refill tube 21 come into contact with each other when the punching is applied from the outside, for example.

The automatic pencil 1 and the chuck mechanism 20 of the present embodiment will be described in detail with reference mainly to Fig. 3 . As shown in the figure, the inner peripheral surface of the sleeve 24 is spaced apart from the outer peripheral surface of the pen core tube 21 at a slight distance, and is relatively movable in the direction of the axis L and the direction orthogonal to the direction of the axis L. When the punch is applied to the mechanical pencil 1 from the outside, the inner peripheral surface of the rear end portion of the sleeve 24 comes into contact with the outer peripheral surface of the pen core tube 21 and slides. The sleeve 24 is movable in a direction orthogonal to the direction of the axis L, and by the portion (the first contact sliding portion) where the pen tube 21 contacts and slides with the sleeve 24, contact sliding (friction sliding) can be used to suppress the sleeve. 24 moves in a direction orthogonal to the direction of the axis L.

The rear end portion of the sleeve 24 abuts more strongly against the outer circumference of the refill tube 21 than the other portions. Therefore, in the present embodiment, the rear end of the sleeve 24 protrudes rearward, and the refill tube 21 at a position rearward in the direction of the axis L is closer to the rear end of the collet 22 that is fitted into the pen core tube 21. The outer perimeter is adjourned. With such a configuration, it is possible to prevent the punch applied from the outside of the mechanical pencil 1 from being transmitted to the collet 22, and the flush is vented to the refill tube 21. The punching force transmitted to the refill tube 21 may be due to the intermediate portion of the longer refill tube 21 between the front end of the refill tube 21 in contact with the sleeve 24 and the rear end portions of the rear end of the press portion 5 It is consumed (absorbed) by vibration or the like, and thus is not easily transmitted to the chuck 22. The intermediate portion of the refill tube 21 can absorb the punch applied from the outside to the mechanical pencil 1 by vibration such as a vibration mode of bow deformation.

An annular projecting portion 24b is formed to protrude inward in the radial direction on the inner peripheral surface of the front end portion of the sleeve 24. The front face of the projection 24b abuts against the rear of the collet ring 23. The front end of the protruding portion 24b (the inner peripheral surface of the sleeve 24) is kept separated in the radial direction of the sleeve 24 without being in contact with the outer peripheral surface of the chuck 22. On the outer circumference of the collet 22 in the sleeve 24, a collet spring 26 (compression coil) that is compressed in the axial direction between the rear surface of the projection 24b and the front end surface of the pen core tube 21 is disposed. The front end of the collet spring 26 is supported in a state of abutting against the rear surface of the protruding portion 24b of the sleeve 24. The rear end of the collet spring 26 is supported in a state of abutting against the front end surface of the pen core tube 21. The collet spring 26 can elastically press the pen core tube 21, the collet 22 fixed to the pen core tube 21, and the collet ring 23 fitted to the collet 22 with respect to the sleeve 24 in the direction of the axis L. When the pen core tube 21, the collet 22, and the collet ring 23 are moved rearward by the elastic pressing force of the collet spring 26, the collet ring 23 is fitted to the collet 22 from the rear.

In the present embodiment, the outer circumference of the chuck spring 26 is in contact with the inner circumferential surface of the sleeve 24 to constitute a part of the contact sliding portion (second contact sliding portion). When the sleeve 24 moves in a direction orthogonal to the direction of the axis L, it slides in a state where the outer circumference of the chuck spring 26 comes into contact with the inner peripheral surface of the sleeve 24. By the second contact sliding portion, it is possible to suppress the movement of the sleeve 24 in the direction orthogonal to the direction of the axis L by contact sliding (friction sliding), thereby absorbing at least a part of the punching force applied from the outside of the mechanical pencil 1. Therefore, the core T can be prevented from being broken.

An annular projection 24a is formed to protrude outward in the radial direction on the outer peripheral surface of the front portion of the sleeve 24. An annular protruding portion 2c is formed to protrude inward in the radial direction on the inner circumferential surface of the barrel 2 so as to face the protruding portion 24a of the sleeve in the axial direction. A buffer spring 25 (compression coil) that is compressed in the direction of the axis L is disposed between the protruding portion 24a of the sleeve and the protruding portion 2c of the barrel. The front end of the buffer spring 25 in the axial direction L is supported in a state of abutting against the protruding portion 24a of the sleeve, and the rear end thereof is supported in a state of abutting against the protruding portion 2c of the barrel. In this manner, the buffer spring 25 is disposed between the sleeve 24 and the barrel 2 and extends in the direction of the axis L. The sleeve 24 can be elastically biased forward by the buffer spring 25.

The front end (i.e., the inner peripheral end) that protrudes inward in the radial direction of the protruding portion 2c of the barrel 2 is separated from the outer peripheral surface of the sleeve 24 by a predetermined pitch in the radial direction. Moreover, the front end (i.e., the outer peripheral end) that protrudes outward in the radial direction of the protruding portion 24a of the sleeve 24 is separated from the inner circumferential surface of the barrel 2 by a predetermined pitch in the radial direction. Further, the outer circumference of the buffer spring 25 and the inner circumferential surface of the barrel 2 are separated by a predetermined pitch in the radial direction. Therefore, the sleeve 24 accommodated in the barrel 2 is elastically supported by the buffer spring 25 elastically biased forward in the direction of the axis L. When the punch is applied from the outside of the barrel 2, it only faces the axis L. The direction in which the directions are orthogonal is shifted by a predetermined amount of movement (moving distance). In the present embodiment, the sleeve 24 is elastically supported by the buffer spring 25 on the barrel 2, so that the elasticity of the buffer spring 25 can be utilized to absorb at least a portion of the punching force applied from the outside of the barrel 2.

Further, in the present embodiment, as described above, since the rear end of the sleeve 24 is disposed to protrude rearward from the protruding portion 2c of the barrel 2 in the direction of the axis L, the protruding portion 2c of the barrel 2 can be The radial direction spacing between the front end and the outer circumferential surface of the sleeve 24 is appropriately set to a predetermined interval. As will be described later in detail, as long as the core T can be prevented from being broken at the position of the front end face of the collet 22, the predetermined interval should be such that the sleeve 24 is allowed to be orthogonal to the axis L as much as possible by a large amount of movement (moving distance). The direction is moved relatively large to absorb the punch applied from the outside of the mechanical pencil 1. For example, the predetermined distance between the front end of the protruding portion 2c of the barrel and the outer peripheral surface of the sleeve 24 in the radial direction is preferably 10% or more of the diameter of the buffer spring 25, and more preferably 30. A pitch of more than %, and the best is a pitch of 50% or more.

The inner circumference of the buffer spring 25 of the present embodiment comes into contact with the outer peripheral surface of the sleeve 24 to constitute another portion (third contact sliding portion) that contacts the sliding portion. By the third contact sliding portion, contact sliding (friction sliding) can be used to suppress the movement of the sleeve 24 in the direction orthogonal to the direction of the axis L, and at least a part of the punching force applied from the outside of the mechanical pencil 1 can be absorbed. Therefore, the core of the refill T can be prevented from being broken. The refill of the automatic pencil T is a brittle material that is easily broken. Therefore, as in the configuration of the mechanical pencil 1 of the present embodiment, the movement of the sleeve 24 due to the allowable movement amount in the direction orthogonal to the direction of the axis L is suppressed by contact sliding, and it is important to prevent the core T from being broken. .

A double cylinder shape having an inner cylinder 4a is formed at the rear of the pen tip 4. The outer circumferential surface of the inner cylinder 4a is kept separate from the inner circumferential surface of the barrel 2 without being in direct contact. A predetermined interval is provided between the inner circumferential surface of the inner cylinder 4a and the outer circumferential surface of the sleeve 24. When the punch is applied from the outside of the mechanical pencil 1 (the barrel 2), the sleeve 24 is movable in a direction orthogonal to the direction of the axis L. . The refill T of the automatic pencil 1 has the highest possibility of breaking the core at the front end portion (the position near the front end surface) of the collet 22 holding the refill T. Therefore, in order to prevent the refill T from breaking when the sleeve 24 moves in the direction orthogonal to the direction of the axis L, the amount of movement of the sleeve 24 is allowed to be smaller as it moves closer to the front end portion of the collet 22. . In other words, the predetermined pitch is preferably increased in proportion to the distance from the front end portion of the collet 22 in the direction of the axis L. Therefore, the predetermined interval between the inner circumferential surface of the inner cylinder 4a of the writing head and the outer circumferential surface of the sleeve 24 is configured to be smaller than a predetermined interval between the above-mentioned barrel 2 and the sleeve 24. By allowing the sleeve 24 to move in a direction orthogonal to the direction of the axis L, the core T can be more effectively prevented from being broken.

On the inner circumferential surface of the inner cylinder 4a of the pen tip 4, a plurality of ribs 4a1 extending in the direction of the axis L are formed in the circumferential direction. The front end surface of the sleeve 24 is in contact with the rear end surface of the rib 4a1 in a state where the spring is biased forward by the buffer spring 25. The front end surface of the sleeve 24 is in contact with the rear end surface of the rib 4a1 to constitute another other portion (fourth contact sliding portion) that contacts the sliding portion. By the fourth contact sliding portion, it is possible to prevent the sleeve 24 from moving in a direction orthogonal to the direction of the axis L by contact sliding (friction sliding), whereby at least a part of the punching force applied from the outside of the mechanical pencil 1 can be applied. absorb. Therefore, the core T can be prevented from being broken. As described above, in the present embodiment, the "suppression" function means that the movement of the sleeve 24 is allowed, but the load (resistance) is applied to the movement of the sleeve 24.

At a substantially central position in the direction of the axis L of the rib 4a1, a segment portion 4a2 is provided which can be abutted when the front end surface of the collet ring 23 advances. When the front end surface of the collet ring 23 abuts against the segment portion 4a2 of the rib portion 4a1 formed in the inner cylinder of the pen tip 4, the collet ring 23 is detached from the collet 22 toward the rear to make the refill T self-clamp 22 The grip is released. A series of output actions of the automatic pencil 1 will be detailed later.

The female screw portion 4b1 is formed on the inner circumferential surface of the outer cylinder 4b which is formed in the rear end portion of the pen tip 4 and has a double cylindrical shape. Further, a male screw portion 2d corresponding to the female screw portion 4b1 of the pen tip 4 is formed on the outer peripheral surface of the tip end portion of the barrel 2. By screwing the female screw portion 4b1 and the male screw portion 2d, the pen tip 4 can be fixed to the barrel 2.

A guide tube 31 that is movable in the direction of the axis L is disposed at a position forward of the front end surface of the collet 22. The guide tube 31 has a disk-shaped base end portion 31b, a center hole through which the refill T is inserted in the direction of the axis L, and a plurality of insertion legs 31a formed to protrude forward from the base end portion 31b around the center hole. As shown in the figure, the front end of the insertion leg 31a has a hook shape and is engageable in the slit 32a formed in the core holder 32 (described later in detail), and can be locked to the core holder 32 and can be oriented in the front-rear direction. Relative movement.

A segment is formed on the outer peripheral edge of the proximal end portion 31b of the guide tube 31. Further, a segment portion of the inner circumference of the pen tip 4 is formed on the inner circumferential surface of the pen tip 4 which faces the segment portion of the proximal end portion 31b of the guide tube 31 in the direction of the axis L. A return spring 36 is disposed between the proximal end portion 31b of the guide tube 31 and the segment of the inner circumference of the pen tip 4, and the return spring 36 is a compression coil that elastically presses the guide tube 31 rearward with respect to the tip 4 in the direction of the axis L. In a state where the guide tube 31 is elastically pressed rearward by the return spring 36, the rear end surface of the proximal end portion 31b of the guide tube 31 approaches the distal end surface of the collet 22 from the front. Further, when the collet 22 advances, the rear end surface of the guide tube 31 abuts against the front end surface of the collet 22 from the front. In a state in which the rear end surface of the guide tube 31 approaches or abuts against the distal end surface of the collet 22 from the front, the refill T that protrudes from the distal end surface of the collet 22 is supported in a direction orthogonal to the direction of the axis L. Therefore, the bending moment of the position where the refill T held by the collet 22 acts on the front end surface of the collet 22 in the direction of the axis L can be alleviated, and the position of the refill T at the front end face of the collet 22 can be prevented from occurring. Broken core.

The core holder 32 is disposed at a position in front of the guide tube 31 so as to be freely movable in the direction of the axis L. The core holder 32 is formed with a plurality of slits 32a extending in the front-rear direction. The hook-shaped front end of the insertion leg 31a of the guide tube 31 is slidably engaged in the slit 32a. Thereby, the guide tube 31 can be engaged with the core holder 32 and can relatively move in the front-rear direction. The core holder 32 is formed with a center hole through which the refill T is inserted in the direction of the axis L. A holding portion that can sandwich and hold the refill T in the radial direction inner side is formed at the front end portion of the center hole of the core holder 32. The core holder 32 is inserted into the distal end tube 30 from the rear and assembled to the distal end tube 30.

A crotch portion is formed at the rear end of the front end tube 30. An O-ring 38 can be mounted on the outer circumference of the crotch portion, and the O-ring 38 can elastically support the front end tube 30 and the core holder 32 in a direction orthogonal to the direction of the axis L. The O-ring 38 is configured to impart appropriate sliding resistance to the movement of the tip end tube 30 and the core holder 32 in the front-rear direction. Here, the appropriate sliding resistance refers to the sliding resistance in which the distal end tube 30 and the core holder 32 can be held to maintain the output refill T in the direction of the axis L. Further, the sliding resistance can allow the movement of the front end tube 30 and the core holder 32, and when a pressing force in the direction of the larger axis L is applied to the front end tube 30 and the core holder 32, the front end tube 30 can be protruded from the writing head 4. Alternatively, the front end tube 30 can be received in the pen tip 4. The outer circumference of the O-ring 38 is pressed in a state of being elastically deformed toward the inner circumferential surface of the opening 4c of the writing head 4. The front end tube 30 and the core holder 32 are elastically supported by the O-ring 38, whereby the O-ring 38 can be used to absorb the portion which is applied from the outside of the mechanical pencil 1. The forward movement of the distal end tube 30 and the core holder 32 is restricted by the abutment of the crotch portion of the distal end tube 30 and the segment formed on the inner circumferential surface of the opening portion 4c of the pen tip.

A series of output actions of the automatic pencil 1 will be described. When the pressing portion 5 at the rear end of the mechanical pencil 1 is pressed, the pen core tube 21 advances against the elastic force of the chuck spring 26. As described above, the collet 22 is fixed to the front end portion of the pen core tube 21. In a state in which the collet ring 23 is fitted to the collet 22, since the collet 22 is pressed inward in the radial direction by the collet ring 23, the refill T is held by the collet 22. Therefore, the collet 22, the collet ring 23, and the refill T will advance together with the refill tube 21. The advancing collet 22 and the abutting guide tube 31 are also pushed forward and advance against the elastic force of the return spring 36. When the guide tube 31 advances, the core holder 32 and the front end tube 30 pushed by the guide tube 31 advance and protrude from the pen tip 4.

When the front end surface of the collet ring 23 advances and abuts against the segment portion 4a2 of the pen tip 4, the collet ring 23 is detached from the collet 22 toward the rear. After the collet ring 23 is disengaged, the collet 22 is opened by its elastic recovery, so that the refill T can be released from the clamping of the collet 22. At a position where the refill T is released from the grip of the collet 22, the refill T is held by the core holder 32. Thereafter, when the pressing portion 5 of the mechanical pencil 1 is released from the pressing, the front end tube 30, the core holder 32, and the refill T are left, and the refill tube 21, the collet 22, and the collet ring 23 are caused by the collet spring 26's stretch and back. The guide tube 31 is retracted by the elastic force of the return spring 36. When the collet ring 23 is again fitted to the outer circumference of the collet 22 by the retraction, the collet 22 grips the portion of the refill T that is relatively rearward. In this manner, the refill T can be output from the mechanical pencil 1 and protrude from the distal end tube 30, and the state shown in FIGS. 2 and 3 can be exhibited.

When the automatic pencil 1 is being written, if the refill T is subjected to a stronger pen pressure than that required for normal writing, the buffer spring 25 is compressed, and the sleeve 24, the collet spring 26, the refill tube 21, the collet 22, The collet ring 23, the refill T, and the pressing portion 5 are retreated backward in the direction of the axis L with respect to the barrel 2. Therefore, the mechanical pencil 1 of the present embodiment can absorb excessive writing pressure and prevent core breakage. Further, as described above, the mechanical pencil 1 of the present embodiment is configured such that the lead tube T in front of the distal end surface of the collet 22 is held orthogonal to the axis L by the guide tube 31, the core holder 32, and the distal end tube 30. The direction of the core can be prevented.

Further, the automatic pencil 1 of the present embodiment can protect the outer portion of the automatic pencil 1 due to dropping or the like as described above, and can protect the refill T from being easily broken. When the mechanical pencil 1 is flushed from the outside due to dropping or the like, the sleeve 24 moves in a direction orthogonal to the direction of the axis L. At this time, the movable amount of the sleeve 24 moving in the direction orthogonal to the direction of the axis L is a predetermined amount of movement which is allowed by the predetermined pitch so that the refill T does not break the core. In the present embodiment, as described above, the predetermined pitch is set to be larger as it goes away from the front end surface of the chuck 22 in the direction of the axis L. Therefore, in terms of the amount of movement of the sleeve 24 in the direction orthogonal to the direction of the axis L, the amount of movement of the rear end portion in the direction orthogonal to the direction of the axis L is greater than the direction of the front end portion toward the direction of the axis L The amount of movement in the direction of intersection.

In order to allow the amount of movement in the direction orthogonal to the direction of the axis L, the arrangement position of the protruding portion 24a of the sleeve 24 elastically supported by the buffer spring 25 is preferably arranged in front of the sleeve 24 in the direction of the axis L. section. For example, the projection 24a of the sleeve 24 is preferably disposed in the front half of the sleeve 24, and more preferably in the distance from the front end of the sleeve 24 to 40% of the entire length of the sleeve 24 in the direction of the axis L. The position is preferably the position of the distance from the front end to 30% of the entire length of the sleeve 24. When configured in this manner, the position of the projection 24a in which the sleeve 24 is disposed can be used as the center of rotation of the sleeve 24 to rotate in the pitch or roll direction, and the rear end portion of the sleeve 24 can be allowed to be longer than the front end portion of the sleeve 24. It moves largely in a direction orthogonal to the direction of the axis L. As shown in this embodiment, the rear end portion of the sleeve 24 is preferably configured as a free end that is not supported by the buffer spring 25 or the like. With this configuration, the rear end portion of the sleeve 24 can be freely moved in a direction orthogonal to the direction of the axis L.

As described above, the movement of the sleeve 24 which is generated in the direction of the allowable movement amount in the direction orthogonal to the direction of the axis L can be contacted by the contact sliding portion (the first to fourth contact sliding portions). Sliding) to suppress. At this time, at least a part of the punching force transmitted from the outside of the mechanical pencil 1 (the barrel 2) to the collet 22 (the refill T) can be consumed and absorbed by the contact sliding (friction sliding) of the contact sliding portion. In particular, the punch applied from the outer side of the mechanical pencil 1 in the direction orthogonal to the direction of the axis L can be satisfactorily absorbed. Therefore, the core T can be prevented from being broken. On the other hand, in order to improve the efficiency of absorbing (lowering) the punching force by the contact sliding (friction sliding) of the contact sliding portion, the friction coefficient of the contact sliding portion can be made higher than that of the other portions of the automatic pencil. Alternatively, the size, shape, or pressing force of each spring constituting the contact sliding portion may be changed, whereby the contact pressure of the contact sliding portion may be higher than that shown in the present embodiment. At this time, the punch applied to the automatic pencil from the outside can be absorbed more efficiently.

Further, the concept that the sleeve is "moved" within a range of a predetermined movement amount (moving distance) of the allowable volume due to the punch from the outside is a sleeve containing the elastically supported sleeve from the outside. The resulting sleeve is "vibrated" in the range of allowable predetermined amplitudes. Further, when "moving" is "vibration", the concept of "suppression" caused by contact with the sliding portion is a concept including "vibration attenuation" caused by the contact sliding portion.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made thereto. For example, the configuration of the contact sliding portion may be configured by using any one of the first to fourth contact sliding portions or a combination of two or more. Further, the embodiment is not limited to the first to fourth contact sliding portions, and the contact sliding portion may be configured to prevent the sleeve from moving in a direction orthogonal to the axial direction. The contact sliding portion may be disposed along any extending direction, and, for example, may be configured such that the contact sliding portion extending in a direction having an arbitrary angle with respect to the axial direction of the mechanical pencil contacts the sleeve and slides, thereby suppressing the sleeve Move in a direction orthogonal to the axis direction.

Claims (4)

 A mechanical pencil comprising: a shaft cylinder; a buffer spring received in the shaft cylinder, wherein the rear end is supported by the shaft cylinder; and a sleeve received in the shaft cylinder, relative to the shaft cylinder by the buffer spring The front side of the axial direction is elastically biased, and is elastically supported by the buffer spring, and is movable in a direction orthogonal to the axial direction by an impact applied from the outer side of the shaft cylinder; the collet spring is accommodated in the sleeve And the front end is supported by the sleeve; the chuck is received in the shaft cylinder for holding the refill; the refill tube is configured to receive the refill received by the shaft cylinder, and is engaged with the collet The chuck is elastically biased toward the rear in the axial direction by the chuck spring, and the sliding portion is configured to prevent the sleeve from moving in a direction orthogonal to the axial direction.    The mechanical pencil of claim 1, wherein the rear end of the sleeve protrudes rearward from the rear end of the collet toward the axial direction, and the sleeve faces the axis due to the punch applied from the outer side of the shaft barrel When the direction is orthogonal to the direction, the inner circumference of the rear end of the sleeve comes into contact with the outer circumference of the pen tube to constitute the contact sliding portion.    The mechanical pencil according to claim 1 or 2, wherein the sleeve has a protruding portion that protrudes outward in a radial direction from a peripheral surface of the sleeve; the cylindrical barrel has a projection protruding inward in a radial direction from an inner circumferential surface of the cylindrical barrel The buffer spring is disposed between the protruding portion of the sleeve and the protruding portion of the barrel in the axial direction; the front end of the protruding portion of the sleeve and the inner circumferential surface of the barrel, and the shaft barrel The front end of the protruding portion and the outer peripheral surface of the sleeve are separated by a predetermined pitch in the radial direction.    The mechanical pencil according to claim 1 or 2, wherein the outer circumference of the collet spring is in contact with the inner circumferential surface of the sleeve to form a part of the contact sliding portion, and the inner circumference of the buffer spring is in contact with the outer circumferential surface of the sleeve In the other portion constituting the contact sliding portion, the outer circumference of the buffer spring is separated from the inner circumferential surface of the shaft cylinder by a predetermined pitch in the radial direction.