JP2000025384A - Double chuck type mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a cost and to effectively perform a rotation inhibiting function by using a slide guiding function also as the rotation inhibiting function by a combination structure of a clip leg and a barrel, thereby simplifying a structure of a rotation inhibiting means and simplifying its assembling. SOLUTION: The double chuck type mechanical pencil comprises barrels 1, 2 for containing longitudinally slidable writing mechanisms, guide grooves 2a formed in rear longitudinal directions of the barrels 1, 2, and a clip member 13 provided at a rear part of a lead tank 4 for constituting a writing mechanism and having a clip 13a disposed out of the barrels 1, 2, a cylindrical body 13b disposed in the barrels 1, 2 and a leg 13c connected to the body 13b. In this case, the leg 13c of the member 13 is slid in a longitudinal direction under the guidance of both the sidewalls of the groove 2a but restricted by both sidewalls of the groove 2a to inhibit rotating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-chuck mechanical pencil comprising a tip chuck for holding a lead and a rear chuck for feeding the lead.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No.
A double-chuck type mechanical pencil as described in Japanese Patent Publication No. 94 has been proposed. In other words, the core held by the tip chuck for holding the lead and the rear chuck for leading the lead is twisted and broken because the tip chuck does not rotate due to rotation of the lead tank or the rotation of the rear chuck. To prevent this from happening,
A means for preventing the knock cap or the like from rotating with respect to the barrel is provided.

[0003]

However, these detent means have a complicated structure, and are difficult to manufacture, especially when the parts are sawn or the like, and the assembly is troublesome and costly. In addition, there was a problem that the detent was not reliable.

Accordingly, the present invention has been made to solve the above-mentioned drawbacks of the conventional double chuck mechanical pencil. In this invention, a combination of a clip leg and a shaft cylinder serves as a sliding guide function and a rotation preventing function. Accordingly, it is an object of the present invention to provide a double-chuck mechanical pencil which has a simplified structure of the rotation-stopping means, simplifies assembly, reduces costs, and has a reliable rotation-stopping function.

[0005]

In order to achieve the above object, a double chuck mechanical pencil according to the present invention is a double chuck mechanical pencil comprising a tip chuck for holding a lead and a rear chuck for feeding the lead. A shaft cylinder housing a writing mechanism slidable in the longitudinal direction,
A guide groove formed in the longitudinal direction of the rear portion of the barrel is connected to a clip provided at a rear portion of the core tank constituting the writing mechanism and located outside the barrel and a tubular body located inside the barrel. And a clip member comprising a leg portion. In the guide groove, the leg portion of the clip member is guided by both side walls of the guide groove and slides in the longitudinal direction, but is restricted by both side walls of the guide groove. As a result, rotation to the side is prevented.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a double-chuck mechanical pencil according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a double chuck type mechanical pencil according to Embodiment 1 of the present invention, and an internal mechanism is slidably provided in a shaft cylinder. That is, the barrel is a front shaft 1 and a rear portion of the front shaft 1 is press-fitted.
And a fixed rear shaft 2.

A leading tool 3 is fixed to the front end of the leading shaft 1 by screwing or bonding. further,
A core tank 4 is provided in a shaft cylinder composed of a front shaft 1 and a rear shaft 2. At the tip of the core tank 5, a rear chuck 5 for core feeding is press-fitted and fixed. A chuck ring 7 is loosely fitted in the chuck portion 5a of the fifth.

A sleeve 8 having a built-in chuck spring 7 is provided outside the rear chuck 5. That is, an inner flange 8a is formed at the distal end of the sleeve 8, and a chuck spring 7 is inserted between the inner flange 8a and the distal end of the core tank 4 to urge the core tank 4 backward. are doing.

A long slot 8b in the radial direction is formed in the side wall of the sleeve 8 to absorb the excessive writing pressure in order to impart elasticity in the longitudinal direction to the sleeve 8 itself. A locking projection 8c is provided. And
The locking projection 8c is locked in a locking hole 9a formed in the rear large-diameter portion of the center shaft 9 provided between the sleeve 8 and the front shaft 1, and the sleeve 8 and the center shaft 9 are integrated. I have.

Therefore, the center shaft 9 will be described in detail. The diameter of the center shaft 9 increases stepwise from the front to the rear. A tip chuck 10 for holding the lead is fixedly provided in the small-diameter portion at the tip of the center shaft 9. Reference numeral 10a denotes a packing for holding a lead mounted in the central shaft 9 behind the distal chuck 10, reference numeral 11 denotes a distal spring mounted between the front portion of the central shaft 9 and the leading tool 3, and reference numeral 12 denotes a spring.
Is an elastic gripper fitted to the grip portion.

Next, the rear part of the barrel will be described.
A guide groove 2a whose rear end is opened in the longitudinal direction is formed in the rear part, and a guide part 2aa that extends outward is formed at the open end of the guide groove 2a as is apparent from FIG. . A clip 13 is provided in the guide groove 2a.
A clip member 13 with a is provided. That is, the clip member 13 is connected to the cylindrical main body 13 located in the rear shaft 2.
b and a leg 13c connecting the tubular body 13b and the clip 13a. The leg 13c is guided by both side walls of the guide groove 2a and slides in the longitudinal direction. It is not regulated and does not rotate sideways.

A knock receiving base 14 as shown in FIGS. 5 to 7 is provided between the inner periphery of the front part of the cylindrical main body 13b and the outer periphery of the core tank 4. That is, the knock cradle 14
Is composed of a large-diameter portion 14a into which the front core tank 4 is press-fitted and a small-diameter portion 14b which is press-fitted into the rear clip member 13, and the large-diameter portion 14a is provided with an engaging rib 14c in the longitudinal direction. Have been.

On the other hand, as shown in FIGS. 2 and 3, an engagement groove 2b is formed in the rear inner peripheral portion of the rear shaft 2 constituting the shaft cylinder, in which an engagement rib 14c of the knock receiving base 14 is engaged. A plurality is formed in the longitudinal direction. Therefore, when assembled, the knock cradle 14 is prevented from rotating with respect to the rear shaft 2 which is a shaft cylinder by the engagement structure of the engagement rib 14c and the engagement groove 2b.

Further, at the rear end of the clip member 13, an eraser receiving portion 13e as an eraser receiving means is provided. An eraser is attached to the eraser receiving portion 13e, and an eraser cover 15 is detachably provided outside the eraser receiving portion 13e. Reference numeral 13ee denotes an opening for refilling the core formed at the bottom of the eraser receiving portion 13e.

The operation of the mechanical pencil according to the above embodiment will now be described. First, as a preparation for writing, the eraser cover 15 is removed from the eraser receiving portion 13e at the rear end of the clip member 13, and further removed from the eraser receiving portion 13e to remove the writing core and eraser receiving portion 13e.
Is filled into the core tank 4 through the opening 13ee. Thereafter, the eraser and the eraser cover 15 are restored.

When writing is attempted in this state, when the eraser cover 15 is knocked, the rear chuck 5 for feeding out together with the lead tank 4 moves forward against the chuck spring 7. During this forward process, the chuck portion 5 at the front of the chuck
The chuck ring 6, which is loosely fitted in the center a, comes into contact with the step 9b formed inside the center shaft 9 and comes off the rear chuck 5, so that the chuck portion 5a of the rear chuck 5 is opened and the lead is advanced. By repeatedly knocking, the lead is advanced, reaches the tip chuck 10 for holding, protrudes from the tip opening of the tip chuck 10, and becomes writable.

According to this embodiment, the clip 1
The leg 13c of 3a is regulated by the side walls on both sides of the guide groove 2a and slides in the front-rear longitudinal direction, but is prevented in the lateral width direction. The rotation is not transmitted to the base 7 via the lead tank 4. Accordingly, the core tank 4 is rotated, and the rear chuck 5 is rotated, so that the core held together with the tip chuck 10 is not twisted and broken.

Next, FIG. 8 shows a second embodiment according to the present invention.
FIG. 2 is a vertical cross-sectional view of a mechanical pencil showing the same. The structure of the front part is the same as that of FIG.

In the figure, a guide groove 2a is formed from the rear end of the rear shaft 2 to the front as in FIG. The leg 13c of the clip 13a of the clip member 13 is disposed in the guide groove 2a. In addition, an eraser is removably loaded in the rear part of the clip member 13, and an eraser receiving member 13f which is an eraser receiving means for the eraser is attached. This eraser receiving member 1
An opening 13ff for refilling the core is formed at the bottom of 3f, and an eraser cover 15 as a knock member is provided outside the eraser receiving member 13f. The eraser receiving member 13f is press-fitted into the clip member 13, but is rotatable.

Further, the cylindrical body 13 of the clip member 13
b is a cam 13 for a ballpoint pen acting as a detent
d, and the engagement rib 3 with which the cam 13d is engaged.
b is formed on the inner wall of the rear shaft 3. Therefore, in this embodiment, even if a rotational force is applied to the clip member 13, the double detent function acts, and the lead tank 4 rotates to rotate the rear chuck 5 and pinch it together with the tip chuck 10. The core does not twist and break. Further, there is an advantage that the clip member 13 according to the present embodiment can be diverted to a ball-point pen if it is used as it is.

FIG. 9 shows a double-chuck mechanical pencil according to a third embodiment of the present invention, which has a very simple structure as compared with the clip member 13 according to the above-described embodiment. That is, the clip member 13
Is an eraser receiving section 1 in which an eraser is directly loaded at the rear.
3e, the core tank 4 is press-fitted in the front part, and the outer diameter of the front part is tapered 13g toward the front. Further, the front end of the tapered portion 13g is chamfered to form a chamfered portion 13gg.

On the other hand, since the annular engaging portion 2c is formed on the inner periphery of the rear portion of the rear shaft 2, the clip member 1
When the tapered portion 13g at the tip of No. 3 is pressed into the rear shaft 2, the tapered portion 13g is guided and inserted inside the annular locking portion 2c. Then, the rear chuck 5 and the core tank 4 are urged rearward by the chuck spring 6, so that the rear end shoulder 13h of the tapered portion 13g is fixed to the annular locking portion 2.
The clip member 13 does not fall off from the rear shaft 3 after being abutted and locked to the front end of the rear shaft 3c.

The tapered portion 13g of the clip member 13
If the chamfered portion 13gg is formed by cutting the outer periphery of the tip end as shown in the drawing, there is an advantage that the clip member 13 can be easily inserted from the rear.

[0024]

According to the present invention, since the clip leg of the clip member connected to the core tank is simply restricted by the side wall of the guide groove of the shaft cylinder as described above, rotation is prevented.
The structure of the detent means is extremely simple, the production of parts is easy, the assembly is not troublesome, the cost can be reduced, and the detent effect is assured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a double chuck mechanical pencil according to Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view showing only a rear shaft of FIG. 1;

FIG. 3 is a cross-sectional view of a cam portion of FIG. 2;

FIG. 4 is a rear enlarged plan view of the rear shaft of FIG. 2;

FIG. 5 is a front view showing only a knock cradle of FIG. 1;

FIG. 6 is a plan view of the knock cradle of FIG. 4;

FIG. 7 is a longitudinal sectional view of the knock cradle of FIG. 4;

FIG. 8 is a vertical sectional view of a double chuck mechanical pencil according to Embodiment 2 of the present invention.

FIG. 9 is a longitudinal sectional view of a double chuck mechanical pencil according to Embodiment 3 of the present invention.

[Explanation of symbols]

 1 front shaft (shaft tube) 2 rear shaft (shaft tube) 2a guide groove 3 front tool 4 core tank 5 rear chuck 6 chuck ring 7 chuck spring 8 sleeve 9 center shaft 10 tip chuck 11 tip spring 12 elastic gripper 13 clip member 13a clip 13b Cylindrical body 13c Leg 13d Cam 13e Eraser receiver (eraser receiver) 13f Eraser receiver (eraser receiver) 13g Taper 13gg Chamfer 13h Shoulder 14 Knock holder 14a Small diameter portion 14b Large diameter portion 14c Engagement Rib 15 eraser cover

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihide Mitani 138 Kawarai-shi, Kawagoe-shi, Saitama F-term inside the Kotobukigawago factory (reference) 2C041 AA06 AB06 2C353 FA04 FC15 FE01 FE18 FG01

Claims (8)

[Claims] 1. A double-chuck mechanical pencil comprising a tip chuck for holding a lead and a rear chuck for feeding the lead, a shaft tube containing a writing mechanism slidable in a longitudinal direction, and a rear length of the shaft tube. A guide groove formed in the hand direction, and a clip provided at the rear of the core tank constituting the writing mechanism and including a clip located outside the barrel and a leg connected to the tubular body located inside the barrel. In the guide groove, the leg portion of the clip member is guided by both side walls of the guide groove and slides in the longitudinal direction, but is regulated by the both side walls of the guide groove to move to the side. A double-chuck mechanical pencil characterized by its rotation prevented. 2. The mechanical pencil according to claim 1, further comprising an eraser receiving means provided at a rear portion of the clip member away from the lead tank and having an opening for refilling the lead at the bottom. 3. The double-chuck mechanical pencil according to claim 2, wherein said eraser receiving means is an eraser receiving member comprising a small-diameter portion press-fit into a cylindrical main body of a clip member and a large-diameter portion to which an eraser is attached. 4. The double-chuck mechanical pencil according to claim 1, wherein the clip member is connected to a lead tank via a knock receiving stand. 5. The knock receiving base includes a large-diameter portion into which a front core tank is press-fitted, and a small-diameter portion into which a rear knock receiving base is press-fitted. 5. A double-chuck mechanical pencil according to claim 4, wherein said engaging groove is provided in a longitudinal direction, and an engaging groove for engaging said engaging rib of said knock receiving stand is formed in a longitudinal direction in a rear inner peripheral portion of said barrel. . 6. The double-chuck mechanical pencil according to claim 1, wherein the clip member is a ballpoint pen cam member. 7. The double-chuck mechanical pencil according to claim 1, further comprising a guiding inclined portion having an outer diameter gradually decreasing toward the front on an outer periphery of a front portion of the cylindrical body of the clip member. 8. The double-chuck mechanical pencil according to claim 7, wherein a chamfered portion is formed at a leading end of the guiding inclined portion.