KR0139153Y1 - Mechanical pencil - Google Patents

Abstract

In addition to reducing the remaining strokes, the relative rotation of the cylindrical body and the knock member is prevented, so that they are rotated so that the cores caught on the front and rear chucks are not twisted and broken. To be able to reciprocate in the outer cylinder (1), the installation lead fill tank (4), the rear chuck (5) fixedly fixed to the front end of the fill tank (4), the chuck ring (6) loosely fitted to the rear chuck (5) Cylindrical body (7), which is installed on the outer periphery of the front part of the fill core tank (4), and has a rear spring (8) installed therein to push the fill core tank (4) to the rear, is installed on the cylindrical body (7) A joint member 9 formed with a locking portion for engaging the cylindrical body 7 and the chuck ring 6 on the inner circumference, a front chuck 11 fixed to the front end of the joint member 9, and the joint member 9 Front pusher installed between the forerunner (2) to push the back) Ring restraining means (7f, 9e) and the outer cylinder which is made of a ring 10, the coupling member 9 can move in the axial direction with respect to the cylindrical body (7), but not to rotate In addition to the rear end stopper member (15) installed at the rear end of (1) and the knock member (17) to be attached to and detached from the rear of the fill tank (4), this knock member (17) is the rear end finishing material (15) Dual-strength mechanical pencil installed with other rotation stopping means (15d, 17c, 15f, 17gg) that can move in the axial direction but not rotate.

Description

Double Chute Pencil

The present invention relates to a double chuck mechanical pencil having a front chuck and a rear chuck, in particular a double chuck mechanical pencil made of a rear chuck that is loosely fitted with a chuck ring and a front chuck to prevent retreat of the core. It is about.

Conventionally, such a dual-type mechanical pencil has been proposed for the purpose of reducing the residual lead mainly, but it is difficult to assemble and disassemble all because of the complex structure. In addition, in this type of dual-shape pencil, when two chucks hold the lead, if one chuck turns for some reason, the strokes held by both chucks are twisted and broken. If the shim is interrupted between the front and rear chucks to hinder the delivery of the lead, or if it is broken and pushed out by pushing the lead before exiting, the broken portion of the front lead and the broken portion of the rear lead become impossible to draw. Will also be.

In other words, when the joint member and the cylindrical body are assembled by screwing together, the lead core is pinched due to broken lead, etc., and the feeding operation is not performed. When the cylindrical body is peeled off from the joint member, the rear chuck is turned. As a result, the front part of the lead held by the front chuck and the rear part of the lead held by the rear chuck are twisted and broken. Then, if the writer turns the knock member or the eraser rubber holder connected to the rear chuck through the center of the chuck inadvertently, the rear chuck also rotates along with the pilsim tank, so that the front part and the rear chuck of the pen tip being held by the front chuck. The left side of the lead, which is held in the box, is likewise twisted and broken.

Therefore, the present invention is provided with a rotary stopper means that the chuck can reciprocate in the axial direction but not rotate, thereby preventing the lead from being damaged by twisting the lead, and removing the pioneer when the lead is broken. Provides a double-shape mechanical pencil that is easy to pull out and easy to assemble so that it does not fall off, and the knock cap is displaced when knocking due to the contact of the polygon upper part of the rear stopper member for rotation stopping with the polygon upper part of the knock cap. The purpose is to prevent the direct contact between the knock cap and the rear end cap member by installing an O-ring on the knock cap so as to prevent the occurrence of metallic noise when it is shaken.

1 is a cross-sectional view showing a part of the double-shape mechanical pencil according to the first embodiment of the present invention.

2 is a front view of the cylindrical body in FIG.

3 is a plan view of the cylindrical body of FIG.

4 is a front view of the joint member in FIG.

5 is a cross-sectional view taken along the line A-A of the joint member of FIG.

FIG. 6 is a partial cross-sectional view showing a modification of the double chute pencil of FIG.

7 is a front view showing a modification of the joint member in FIG.

8 is a cross-sectional view of the rotationally supported cylindrical body used for the joint member of FIG.

9 is a cross-sectional view showing another modification of the joint member in FIG.

FIG. 10 is a cross-sectional view of the rotation stopping cylindrical body used for the joint member of FIG.

Figure 11 is a cross-sectional view showing a part of the double churn pencil according to a second embodiment of the present invention.

FIG. 12 is a cutaway view of the rear end closure member of FIG. 11; FIG.

13 is a sectional view taken along the line B-B of the rear end closure member of FIG.

14 is a longitudinal sectional view showing the knock cap of FIG.

FIG. 15 is a bottom view of the knock cap in FIG.

FIG. 16 is a cross-sectional view showing main parts of a double-shape mechanical pencil according to a modification of the second embodiment of the present invention. FIG.

17 is a cross-sectional view taken along line C-C of FIG.

18 is a perspective view of the knock cap in FIG.

19 is a plan view of the knock cap in FIG.

20 is a side view of the knock cap in FIG.

* Explanation of symbols for main parts of the drawings

1: External cylinder 1a: Female thread

2: pioneer 2a: staircase

3: knock cap 4: fill tank

5: rear chuck 5a: front end

6: chuck ring 7: cylindrical body

7a: flange 7b: small diameter part

7c: large diameter part 7d: bullet part

7e: small hole 7f: locking projection (rotation stopping means)

8: rear spring 9: joint member

9a: small diameter part 9b: inclined part

9c: middle diameter part 9d: large diameter part

9e: locking hole (rotation stopping means) 9f: guide cutout

9g: Guide groove 9h: Saw blade shape slit

10: front spring 11: front chuck

12: sleeve 13: rotational stop cylindrical

13a: locking projection (rotation stopping means) 14: spring

15: rear end cap member 15a: head

15b: Leg 15c: Male thread

15d: Octagonal part (polygonal part) 16: Eraser rubber holder

17: knock cap 17a: head

17b: annular convex portion 17c: octagonal portion (polygonal portion)

17d: lower part 17e: face picking part

17f: upper flange 17g: lower flange

17gg: Obstruction 18: O-ring

19: metal jacket

The present invention for achieving the above object, the outer cylinder is installed in the front, the pen core tank installed to reciprocate in the outer cylinder, the rear chuck fixed to the front portion of the pen core tank, it is fitted loosely to the rear chuck Chuck ring, the cylindrical body is installed on the outer periphery of the front end of the fill core tank and fitted with a rear spring for pushing back the fill tank in the interior, the hook is installed on the cylindrical body and the cylindrical body and the chuck spring is caught in contact with the inner circumference An additionally formed joint member, a front chuck fixed to the front end of the joint member, and a front spring installed between the piling member to push the joint member backwards, wherein the cylindrical body is axially coupled to the joint member. It is possible to move in the direction, but the rotation preventing means is installed so as not to rotate.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 to 5 are longitudinal cross-sectional views showing a part of the double-shape mechanical pencil according to the first embodiment of the present invention with a part omitted, and the precursor is screwed at the front end of the outer cylinder (1). . In addition, the pen tip tank (4) installed at the rear end so that the knock cap (3) can be attached and detached is installed to reciprocate in the outer cylinder (1), and the rear end chuck (5) at the front end of the fill tank (4). ) Is fixed by press fitting, and the chuck ring 6 is loosely fitted to the front end portion 5a of the rear chuck 5.

Further, a rear spring 8 is fitted between the elastic cylindrical body 7 which is in contact with the rear end of the chuck ring 6 and the front end of the fill core tank 4. That is, this cylindrical body 7 has the flange 7a which faces inward at the front end, and the back spring 8 is inserted in the inside of this flange 7a, and this back spring 8 is filled with the fill core tank 4, etc. It is supposed to be pushed backwards.

Meanwhile, referring to FIGS. 2 and 3, the structure of the cylindrical body 7 will be described. The cylindrical body 7 has a front small diameter portion 7b and a rear large diameter portion 7c and between them. It consists of 7 shots of bullets, and the whole is comprised from the shock absorbing sleeve. As shown in the drawing, the shot portion 7d has a shot function in which a plurality of small holes 7e are alternately drilled along the axial direction to be stretched in the axial direction, and the shot portion 7d A pair of engaging projections 7f are formed in the outer circumferential portion so as to enter and engage the engaging holes 9e of the joint member 9 described later. In this case, the locking projection 7f has a trapezoidal shape as shown in FIG.

Then, on the outside of the cylindrical body 7, a joint member 9 as shown in Figs. 4 and 5 is hooked and assembled by a step. In other words, a small diameter portion 9a having a stepped step is formed on the front portion of the joint member 9, and an inclined portion 9b is formed on the rear side of the small diameter portion 9a. Following the inclined portion 9b, the intermediate diameter portion 9c is formed. In addition, a large diameter portion 9d is formed at the end, and a locking hole 9e is drilled in the side wall of the large diameter portion 9d. The guide notch 9f which becomes wider gradually is formed. Here, the guide notches 9f are formed so that the locking projections 7f are easily fitted when the cylindrical body 7 is assembled, while the guide grooves 9g are connected to the guide notches 9f: If the dotted line) is formed inside, the cylindrical body 7 is more likely to be fitted to the joint member 9.

In addition, the front spring 10 is fitted between the front end of the small diameter portion 9a of the joint member 9 and the inner wall portion of the precursor 2 so that the joint member 9 is pushed backward. On the other hand, in the first embodiment, the elastic force of the front spring 10 described later is weaker than the elastic force of the rear spring 8 from an operational point of view.

In addition, the front chuck 11 for penetrating pincers is fixed to the front end of the small diameter portion 9a of the joint member 9 by the press-fitting. Unlike the rear chuck 5, which is made through the process of spreading outward, it is made only by the division process. Here, the front chuck 11 is assembled to the front end 2 and holds the lead so that the front chuck 11 is prevented from falling in the state where the front chuck 11 is advanced. It is supposed to have the power to intercept.

In addition, a bar for moving stops 11a is formed at a portion protruding from the front end 2 of the front chuck 11, and the mobile stop projections 11a will be described in more detail as follows. In other words, the front chuck 11, as shown in the state in which the front of the pendulum (11) opens outwards and protrudes from the precursor (2), but in the state of not holding the front of the front chuck (11) is closed and retreat backward In this case, since there is a projection 11a for moving blocking, it does not retreat more than necessary. Therefore, when the front end 2 is removed, there is no fear of the front chuck 5 falling off and lost.

On the other hand, in the state where the front chuck 11 is assembled to the front end 2 and protrudes from the front end 2 and moves forward, the front end is held to the extent that the core is prevented from falling. While the pen tip clamping force is such that the pen tip is moved, while the front chuck 11 is in a retracted state, the pen tip can be endured to hold the pen tip. Incidentally, reference numeral 16 in FIG. 1 denotes an eraser rubber holder installed at the rear end of the fill tank 4 to be described later to hold the eraser rubber.

Next, a description will be given of the operation of the dual-type mechanical pencil according to the first embodiment of the present invention configured as described above.

When knocking the knock cap 3 at the rear end for writing, the front spring 10 is first compressed because the elastic force of the front spring 10 is weaker than that of the rear spring 8. Since the front chuck (11) is advanced to open, the penmanship from the back foot can go inside.

Subsequently, when the inclined portion 9b of the fitting member 9 comes into contact with the stepped portion 2a formed inside the pioneer 2, the rear spring 8 is compressed to form the rear chuck 5 together with the fill tank 2. This is advanced. As the rear chuck 5 moves forward, the chuck ring 6 reaches the stepped portion formed inside the joint member 9 so that the rear chuck 5 is opened by the weight. After the knock is released, the rear chuck 5 is returned to the initial position. Subsequently, when the knock operation is performed again, the rear chuck 5 is advanced to move the inside of the joint 9 in the state of holding the lead, thereby pushing the lead. At this time, the front end of the front chuck 11 is protruded from the front end in the state held in this front chuck 11.

On the other hand, if the lead is worn out during writing, the knock cap (3) at the rear end is knocked out again and the lead is sent out.However, even when the length of the lead is shortened, the knock operation is repeated to release the new lead in the tank. When the new lead pushes out the worn lead, it can continue to be used.

In addition, when the lead is protruded from the front chuck 11 too much, press the knock cap 3 of the rear end to open the chuck a little, and then press the front end of the lead to return the lead, and accordingly the protrusion of the lead The length can be adjusted so that the lead can be prevented from breaking during use.

In addition, when the core is broken and caught inside, the cylindrical body 7 may be rotated by turning the front end 2 with respect to the outer cylinder 1, releasing the screw, detaching the front end 2, and then rotating the cylindrical body 7. The locking projection 7f of the c) is caught by the locking hole 9e of the joint member 9 so that the cylindrical body 7 is prevented from rotating relative to the joint member 9, so that both are integrated. Thus, for example, even if the rear chuck 5 and the front chuck 11 bite the same one of the cores, the cores are not twisted and broken. Here, when the cylindrical member 7 is to be peeled off from the joint member 9, the pair of locking projections 7f of the cylindrical member 7 can be pulled out in the rearward state by pressing inwards in the radial direction, respectively. .

6 illustrates a partial cross-sectional view of a variant of the dual-strength mechanical pencil of FIG. 1. In the above description, the cylindrical developing member to be assembled to the joint member 9 is described as a cylindrical body 7. However, in other words, the connecting member 9 connected to the front chuck 11 may not be rotated with respect to the cylindrical member, but only a rotation processing means may be provided so as to only move in the axial direction. Here, for example, the cylindrical member may be composed of three parts, a sleeve 12 on the front part, a rotation-stopping cylindrical body 13 on the rear part, and a spring 14 provided therebetween, instead of the cylindrical body 7. In this case, since the cylindrical body 7 is made of a so-called shock-absorbing sleeve, an independent spring 14 is used, so that more sufficient elasticity can be obtained.

In FIG. 6, as in FIG. 1, the sleeve 12 is installed at the front portion of the coupling member 9 so as to contact the rear end of the chuck 6, and at the rear locking hole 9e, the rotary blocking cylindrical body is provided. (13) is to be caught. In addition, a spring 14 is provided between the sleeve 12 and the rotary stopping cylindrical body 13, and the operation of the mechanical pencil according to this modification is similar to that described in connection with the previous embodiment. Because of this, description thereof is omitted.

7 and 8 show a modification of the joint member 9 and the rotary-blocking cylindrical body 13 in FIG. 6, that is, the large diameter portion 9d of the joint member 9 in FIG. Four locking holes 9e are formed at an appropriate distance and aligned in the axial direction, and the rotation stopping cylindrical body 13 appropriately selected in accordance with the elastic force of the spring 14 provided in these locking holes 9e. The locking projection 13a is caught. For example, in order to maximize the resilience force of the spring 14, the locking projection 13a of the rotation stopping cylindrical body 13 is caught by the locking hole 9e at the foremost side. What is necessary is just to be caught by the hole 9e. On the other hand, the locking projection 13a of the rotation stopping cylindrical body 13 should just have a triangular cross section as shown in FIG.

9 and 10 show other modifications of the joint member 9 and the rotary-blocking cylindrical body 13 in FIG. 6, and the large diameter portion 9d shown in the joint member 9 in FIG. The slits 9h in the form of saw blades are formed instead of the engaging holes 9e, and the slits 9h are similar to the four engaging holes 9e in step by step. Can be adjusted. In this case, the locking projection 13a of the rotation stopping cylindrical body 13 may have a rectangular cross section as shown in FIG.

11 to 15 show a double-shape mechanical pencil according to a second embodiment of the present invention. In this second embodiment, even when the writer tries to rotate the knock cap of the knock member, Rotation is prevented and the lead is prevented from breaking by twisting.

11 is a longitudinal cross-sectional view showing the front portion of the present double-tipped mechanical pencil, the rear end of the outer cylinder (1) is fixed by screwing the hollow rear cap member (15). 12 and 13, the rear end stopper member 15 is composed of a head portion 15a and a leg portion 15b protruding from the outer cylinder 1, and the leg portion 15b. The outer periphery of the screw 15c is formed and is coupled to the screw 1a formed in the inner periphery of the outer cylinder 1. The inner circumference of the head 15a is configured to form a cross-sectional octagonal portion 17c. Reference numeral 15e in FIG. 12 denotes a face picking portion.

In addition, an eraser rubber holder 16 having an eraser rubber is installed at the rear end of the fill tank 4, so that the knock cap 17, which is a knock member, can be extracted from the eraser rubber holder 16. It is installed. 14 and 15, the knock cap 17 has a hemispherical head 17a, and an annular convex protrusion 17b for preventing shaking is formed at the bottom thereof. The outer circumference of the convex portion 17b forms an sectional octagonal portion 17c as shown in FIG.

According to the second embodiment of the present invention, even if the writer turns the knock cap 17 inadvertently, the outer circumference of the knock cap 17 is formed as an octagonal portion 17c, while correspondingly the rear end cap member 15 Since the inner circumference of the octagonal portion 15d is fitted to each other, the knock cap 17 does not rotate with respect to the rear end cap member 15, so that the fill tank 4 rotates to the rear chuck 5 ) And the front chuck (11) is caught in the pen will not be twisted and broken.

On the other hand, even when the knock cap 17 is inserted into the rear end cap member 15, both of them have a polygonal upper portion, so that the operator does not have to be particularly aware of the direction such as inserting the rib into the groove, so that the assembly workability You get better.

In addition, if the surface picking portion 17e is formed in the angular portion of the octagonal portion 17c of the knock cap 17 as shown in FIG. 15, the rear end closure member as shown in FIG. It works together with the face picking part 15e formed in the inner periphery of the upper end of 15 so that the assembly workability can be further improved.

On the other hand, in the second embodiment as described above, the octagonal portions 17c and 15d are respectively formed on the outer side of the annular convex portion 17b of the knock cap 17 and the inside of the head portion 15a of the rear end cap member 15. Although it is intended to be formed, an octagonal cross section is formed on the outside of the lower end portion 17d that is lower than the annular convex portion 17b of the knock cap 17 and the inside of the leg portion 15b of the rear end cap member 15, respectively. The same effect can be obtained. In the above description, the case where the cross section is an octagonal shape has been described. That is, of course, a polygonal shape other than the octagonal shape may be used.

In this case, it is also applicable to the mechanical pencil as shown in FIG. 1 without using the rear end closure member 15, and instead of the rear end closure member 15, a polygonal upper portion is formed inside the rear end of the outer cylinder 1, The rotation preventing means may be constituted by fitting the upper polygonal portion formed outside the knock cap 3 or the eraser rubber holder 16 on the upper polygonal portion. In particular, when the polygonal upper portion is formed in the eraser rubber holder 16 so as not to rotate relative to the outer cylinder 1 in FIG. 1 or the rear end cap member 15 in FIG. 11, the knock cap 3, 17) When the peel tank is rotated even when peeled off, the rear chuck (5) is rotated together, there is an advantage that the lead will not be broken.

16 to 20 show a modification of the rotation stopping structure shown in the second embodiment of the present invention shown in Figs. 11 to 15, in this modification the second embodiment Compared with the structure in which the polygonal upper portion of the rear end cap member and the polygonal upper portion of the knock cap are fitted, there is a better effect. That is, six axially extending locking grooves 15f are formed at equal intervals inside the large diameter portion of the upper end portion of the rear end closure member 15, and in the rear end closure member 15, The knock cap 17 is fitted to be pulled out.

In more detail, the knock cap 17 has an upper flange 17f and a lower flange 19g formed in parallel with the leg portion, which is a lower portion that is fitted into the rear end cap member 15 while having a flat shape. Formed. In addition, three locking projections 17gg are formed at intervals of 120 ° around the lower flange 17g, and these locking projections 17gg are formed when the knock cap 17 is inserted into the rear end cap member 15. Each is engaged with the engaging groove 15f formed in the rear end cap member 15.

As a result, the knock member 17 can reciprocate in the axial direction with respect to the rear end cap member 15, but since rotation is inhibited, the rear chuck 5 that is press-fitted to the front end of the fill tank 4 is fixed. : FIG. 1) also prevents rotation, and prevents the broken lead which is hold | maintained with the front chuck (11: FIG. 1) to twist and break.

In addition, as shown in FIG. 16, an O-ring 18 made of an elastic material such as rubber is inclined between the two flanges 17f and 17g of the knock cap 17. The knock cap 17 inserted into the stopper member 15 is reliably held by the back end stopper member 15 so as not to play between the two members, so that metallic noise is not generated even if shaken. Reference section 19 of FIG. 16 is a metal jacket which is designed to hold and support the lower portion of the eraser rubber.

In addition, as described above, the three engaging projections 17gg are formed at equal intervals only around the lower flange 17g, so that when the molding foam of the knock cap 17 is a metal part molded by die casting, When sand is put in a rotary cylinder where something like sand is used to remove a fire, there is an advantage that sand or the like will not be pulled out even if it is caught in the air gap between these flanges 17f and 17g. .

On the other hand, in the above embodiment, six axial locking holes 15f of the rear end closure member 15 are formed, but more than or at least as long as they are larger than the number of the locking projections 17gg of the knock cap 17. none. In other words, if the number is large, there is an advantage that the directionality of the locking projection 17gg does not need to be considered when the knock cap 17 is coupled to the rear end cap member 15. In addition, in the above embodiment, although the engaging projection 17gg is formed only in the lower pull flange 17g, it may be formed in the upper flange 17f.

As described above, according to the present invention, since the rotation stopping means is provided between the joint member and the cylindrical member, the knock member and the rear end stopper member or the outer cylinder, the eraser rubber holder and the outer cylinder, respectively, if any of the two is rotated, One side of the chuck is rotated, and as a result, the maneuver of the front and rear chuck is not twisted and broken, thereby improving the operability.

In addition, even when a broken lead is caught inside, the pioneer can be easily pulled out, and the front chuck is not dropped and lost, and the front chuck is not dropped, and the assembly workability is improved. .

In addition, in the state where the polygonal upper portion of the rear end cap member 15 and the knock cap 17 are in contact with each other, the knock cap 17 is displaced during knocking, and there is no fear of overlapping the knock, and the metal members are in contact with each other. This prevents the occurrence of metallic noise when shaking.

Claims (11)

An outer cylinder 1 having a front end 2 installed therein, a fill tank 4 installed so as to reciprocate in the outer cylinder 1, and a rear chuck 5 fixed at the front end of the fill tank 4, which is Cylindrical member with chuck ring (6) loosely fitted to rear chuck (5), and upper spring (8) installed on the outer periphery of the front part of the fill core tank (4) and pushing the fill core tank (4) to the rear. Is installed on the outside of the cylindrical member (7) is a joint member (9) having a stepped portion that is caught in contact with the cylindrical member and the chuck ring 6 on the inner circumference, the front chuck fixed to the front end of the joint member (9) (11) and a front spring (10) provided between the forerunner (2) for pushing the joint member (9) to the rear, the cylindrical member axially with respect to the joint member (9) Can be moved to but not rotating means for rotating 2 jungcheok formula Shah sick pencil that. 2. The locking hole according to claim 1, wherein the rotation stopping means comprises a locking hole formed in the joint member 9 such that the locking projection 7f formed on the cylindrical member and the locking projections 7f and 13d of the cylindrical member are engaged. 9e) two-fold mechanical pencil, characterized in that consisting of. 2. The cylindrical member according to claim 1, wherein the cylindrical member is formed of a cylindrical member (7) formed of an impact-absorbing slab which is formed integrally with an elastic portion 7d having elastic restoring force in an intermediate portion thereof and can be stretched in the axial direction. Characteristic double chute mechanical pencil. 2. The cylindrical member according to claim 1, characterized in that the cylindrical member is composed of three parts: a rotary stop cylindrical body (13) having a front sleeve (12) and a rear locking portion and a spring (14) installed therebetween. Double-shape mechanical pencil. An outer cylinder 1 having a front end 2 installed therein, a fill tank 4 installed so as to reciprocate in the outer cylinder 1, and a rear chuck 5 fixed at the front end of the fill tank 4, which is Cylindrical member installed on the chuck ring 6 loosely fitted to the rear chuck 5 and the rear spring 8 installed on the outer circumference of the front of the fill tank 4 and pushing the fill tank 4 back to the inside. A joint member 9 installed on the cylindrical member and having a stepped portion to which the cylindrical member 7 and the chuck ring 6 come into contact with each other, respectively, and a front chuck fixed to the front end of the joint member 9; 11), the front spring (10) installed between the front end (2), the rear end stopper member (15) installed at the rear end of the outer cylinder (1) to push the joint member 9 to the rear, the fill tank It consists of a knock member detachably attached to the back of the (4), this knock member is the rear end stopper member (15) Be about to move in the axial direction, but the rotation may prevent two jungcheok formula Shah ill pencil, it characterized in that the rotation preventing means is provided to be. 6. The knock cap (17) according to claim 5, wherein the knock member (14) comprises a knock cap (17) connected to the fill core tank (4) via an eraser rubber holder (16). A double pencil-shaped pencil, characterized in that consisting of a cross-sectional polygonal upper portion (17c) formed in the outer peripheral portion of the cross-sectional polygonal upper portion (15a) formed in the rear end cap member (15) correspondingly. The surface picking portions 15e and 17e of the polygonal upper portion 17c of the knock cap 17 and the upper end of the polygonal upper portion 15d of the inner circumference of the rear end cap member 15, respectively. Double chute mechanical pencil, characterized in that formed. The knock cap (17) according to claim 5, wherein the knock member (14) comprises a knock cap (17) attached to the eraser rubber holder (16) provided at the rear end of the silp tank (4). While the engaging projection 17gg is formed on the outer circumference, the double-chamber sha, characterized in that the engaging groove 15f extending in the axial direction is formed in the inner circumference of the rear end cap member 15 so that the engaging projection 17gg is engaged. A pencil. The method of claim 8, wherein the locking projection (17gg) of the knock cap 17 is at least one of the pair of flanges (17f, 17g) formed to be spaced apart at regular intervals up and down the outer periphery of the leg portion of the knock cap 17 While being formed, the O-ring 18 is sandwiched between these flanges 17f and 17g. An outer cylinder 1 having a front end 2 installed therein, a fill tank 4 installed so as to reciprocate in the outer cylinder 1, and a rear chuck 5 fixed at the front end of the fill tank 4, which is Cylindrical body with chuck ring (6) loosely fitted to the rear chuck (5), the rear spring (8) is installed on the outer periphery of the front of the fill tank (4) and pushes the fill tank (4) to the rear. 7), the joint member 9, which is installed on the cylindrical member 7 and has a stepped portion to which the cylindrical member 7 and the chuck ring 6 come into contact with its inner circumference, is fixed to the front end of the joint member 9, respectively. The front chuck (11) installed, the front spring (10) installed between the front end (2) for pushing the joint member (9) to the rear, and detachably attached to the rear of the fill tank (4) Made of a knock member, the knock member can be moved in the axial direction with respect to the outer cylinder 1, but cannot be rotated. 2 jungcheok formula Shah ill pencil, characterized in that rotation preventing means are equipped to. An outer cylinder 1 having a front end 2 installed therein, a fill tank 4 installed so as to reciprocate in the outer cylinder 1, and a rear chuck 5 fixed at the front end of the fill tank 4, which is Cylindrical body with chuck ring (6) loosely fitted to the rear chuck (5), the rear spring (8) is installed on the outer periphery of the front of the fill tank (4) and pushes the fill tank (4) to the rear. 7), the joint member 9, which is installed on the cylindrical member 7 and has a stepped portion to which the cylindrical member 7 and the chuck ring 6 come into contact with its inner circumference, is fixed to the front end of the joint member 9, respectively. The front chuck 11 installed, the front spring 10 installed between the front end 2 to push the joint member 9 to the rear, and the eraser rubber holder installed at the rear of the fill tank 4 (16), the eraser rubber holder 16 can be moved axially with respect to the outer cylinder 1, but the rotation is Dual-shape mechanical pencil, characterized in that it is equipped with a rotary stop means to prevent it.