JPS62212198A - Propelling pencil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a mechanical pencil in which the lead is automatically advanced by releasing writing on a slider from a paper surface, etc., and in which the slider can be locked in a retracted position when not in use.

[Conventional technology]

Recently, various so-called automatic mechanical pencils have been proposed, which have a structure that combines a slider that can slide freely within the tip and multiple springs, etc., and can automatically feed the lead by releasing the pressure of the slider from the paper surface. ing. However, all of them have problems in that the internal structures such as the core delivery mechanism are very complicated, the assembly work is inefficient, and the number of parts is large, making them expensive. Therefore, the present applicant has provided a mechanical pencil designated as Special No. 111N No. 1986-298641 as an automatic mechanical pencil that solves the above-mentioned problems. According to this mechanical pencil, the internal structure is simplified and the lead feeding operation can be performed in three ways, and the lead feeding operation by the knock at the tip can be used not only when the lead does not protrude, but also when the lead protrudes excessively by more than a predetermined amount. The effect of being able to always maintain a constant amount of protrusion was obtained.

[Problems to be solved by the invention]

However, in the mechanical pencil of the earlier application, the slider moves independently and the lead is sent out by this movement, so when you carry it around after use, for example, when you insert it into your pocket. The slider moved backward unnecessarily and the core was unintentionally delivered, resulting in new problems such as staining clothes and breaking the core.

[Summary of the Invention] This invention was made to further solve the problems of the above-mentioned earlier application. In addition to the effects of the above-mentioned earlier application, the slider is locked when the lead is stored to prevent the lead from accidentally protruding. The aim is to obtain a mechanical pencil that will be used.

【Example】

An embodiment of this invention will be described below based on the drawings. As shown in FIG. 1, the outer cylinder 1 has a tip 2 at its tip, and a core pipe 3 inside thereof so as to be slidable in the front axial direction. A tip receiver 4 is fitted to the tip of the core pipe 3, and a core delivery mechanism 5 is disposed on the tip side of the tip receiver 4 at an interval of a contact distance (a). The tip receiving portion 4 has a tip hole 4a that presses and engages the rear end of a sliding handle 6, which will be described later, and the tip receiving portion 4 is movably engaged with the sleeve 7. Here, the engagement between the tip receiving part 4 and the sleeve 7 is such that the two move in one direction until the sleeve 7 comes into contact with the tip tube 9.
After that, any structure may be used as long as the engagement allows only the tip receiving portion 4 to move forward, such as the one shown in the second figure. FIGS. 2(a) and 2(b) show an embodiment of the sleeve 7, in which a groove 7b that movably engages with the convex portion 4c of the tip receiving portion 4 is formed. This groove 7b is provided with a protrusion 7C, and the groove width A of this portion is formed smaller than the width B of the protrusion 4c. , and both move in one direction. After that, the convex portion 4c pushes the protrusion 7c open and moves forward, and only the tip receiving portion 4 is formed so that it can move forward to the tip of the groove 7b. Particularly, to explain in detail about FIG. 2(c), since an inclined part 7d which is narrower in width than the convex part 4c is formed in series with the protrusion 7c of the groove 7b, after the convex part 4c crosses the protrusion 7c. The convex portion 4c also moves forward while pushing and expanding the inclined portion 7d. Further, FIG. 2(c) also shows another embodiment of the sleeve 7,
A rough surface 7e that provides a predetermined resistance to the convex portion 4c on a part of the groove 7b.
is formed. This rough surface 7e provides resistance to the convex portion 4c until the sleeve 7 comes into contact with the tip tube 9, causing the tip receiving portion 4 and the sleeve 7 to move integrally, and thereafter. Only the tip receiving part 4 can move forward. FIGS. 2(d) and 2(e) similarly show other embodiments of the sleeve 7, in which a bent groove 7b is formed and the sleeve 7
and the tip receiving portion 4 are formed to be movable in the same manner. In particular, the width A of the groove 7b in FIG. 2(d) is the width B of the convex portion 4c.
The width C is narrower and provides a predetermined resistance to the protrusion 4c, and the width C is wider than the width B of the protrusion 4c.
are formed to allow the above-mentioned movement. Further, the groove 7b in FIG. 2(e) is also formed with a rough surface 7e that provides a predetermined resistance to the convex portion 4c. Furthermore, FIG. 2(f) also shows another embodiment of the sleeve 7, which has a bent shape. W1b is formed on the sleeve 7. The width A of this v<'G 7 b is formed narrower than the width B of the convex portion 4c, and as in the above embodiment, both move integrally until the sleeve 7 comes into contact with the front cylinder 9, and then Only the tip receiving portion 4 is formed to move forward. FIG. 2(g) also forms a protrusion 7c and locking slopes 7fl, 7f2 in the bent groove 7b, and has the same effect as each of the above embodiments. In addition, in the embodiments shown in FIGS. 2(a) to (g), the convex portion 4c
A pair of grooves 7b are formed facing each other. In addition, as shown in the first figure, the rear end of the sleeve 7 and the tip receiving part 4
A distance (b) is provided between the flange portion 4d and the flange portion 4d. In addition, the lead feeding mechanism 5 includes a ball 11 which is divided into two parts or is held in a ball holding part 10 on the head of the lead chuck 6, and a ball 11 which is attached to the inside of the lead chuck 6, and the rear end is attached to the above-mentioned tip. It has a sleeve 7 engaged with the receiving part 4, and a first elastic body 12 for clamping the chuck that is elastically attached between the sleeve 7 and the locking step 6a of the lead chuck 6. The lead chuck 6 is formed of a metal molded product formed by forging or pressing, a sintered alloy, or a synthetic resin formed by injection molding or compression molding. In this embodiment, the lead chuck 6 is arranged in two directions along the axis of the core insertion hole 60 as shown in FIGS. 1, 3, and 4.
It consists of a pair of chuck members 61 and 62 which are divided into parts, each having a hemispherical cross section, and include the ball holding part 0, a rear locking step 6a, and a rear end of the locking step 6a. A rear tapered cylindrical portion 6b that extends rearward and gradually becomes smaller in diameter on the rear end side, the core insertion hole 60 in the axial center portion, and an engagement recess 7.
1.72, engagement convex portion 70.73, and opening/closing fulcrum convex portion 74.
75. Here, in the above-mentioned engagement unevenness, the engagement protrusion 70 of one chuck member 61 is connected to the engagement recess 70 of the other chuck member 62.
The chuck members 61 and 62 are respectively engaged with each other to prevent the chuck members 61 and 62 from shifting from each other in the axial direction. In addition, the opening/closing fulcrum convex portion 74.7 of the chuck member 61.62
5 are brought into contact with each other, and the chuck members 61 and 62 function as a fulcrum for levering in the opening/closing direction, and there is a sufficient clearance K to allow smooth levering (see Fig. 1).
It has a spacer function to form. The inner wall of the head of this lead chuck 6 has teeth 6.
3,64 are formed. The teeth 63 and 64 are connected to the chuck members 61 and 62, as shown in FIGS. 3 to 8.
A plurality of center tooth portions 63 are arranged at regular intervals along the center line direction of the inner peripheral surface of the half core insertion hole 60, and a plurality of center tooth portions 63 are arranged alternately at regular intervals between these center tooth portions 63 and are located on both sides. It consists of side teeth portions 64 that shift. In these tooth portions 63, 64, the center tooth portion 63 consists of front and rear tapered surfaces 63a and vertical surfaces 63b at both ends, and the side tooth portions 64 consist of front and rear tapered surfaces 64a, vertical surfaces 64b of the inner end wall, and outer end walls. The side teeth 64 have a half core insertion hole 60 between the center teeth 63.
It has an arrangement configuration in which it overlaps the center tooth portion 63 at a constant interval along the inner circumferential surface of the tooth portion. Therefore, each of the tooth portions 63 and 64 has a sharp tip, and a tooth groove bottom 63c. 64d is formed in a planar shape. Since the teeth 63 and 64 are arranged alternately at regular intervals, it is difficult for dust such as core dregs to accumulate.Furthermore, each tooth groove bottom 63c
, 64d are formed in a flat shape, which also makes it difficult for dust such as core dregs to accumulate. In addition, if the arrangement structure of each tooth portion 63, 64 can properly hold the lead and effectively remove the accumulation of lead waste, for example,
As shown in Figure 9, it has a square and square shape. Any array etc. may be used. Furthermore, each tooth part 63.6
4 may be spaced apart from each other in the front, rear, left and right directions, or may be provided continuously as shown in Figure 1O. The pole 11 held at the head of the lead chuck 6 is connected to the inner tapered wall 7 at the tip of the sleeve 7 as shown in the first figure.
A metal tube 7h made of stainless steel or the like is fitted and attached to g as necessary. This metal tube 7h allows reliable, durable and stable rolling contact, and also ensures reliable core holding of the lead chuck 6 and increases durability. Here, the metal cylinder 7h is not necessarily necessary, and in normal use, the inner tapered wall 7g may be formed in such a way that it comes into contact with the ball 11, and the metal cylinder 7h may be omitted. Further, as shown in FIG. 1, an annular lid portion 72 may be provided at the tip of the tapered inner surface 7g of the sleeve 7 or on the inner wall of the tip of the metal cylinder 7h, if necessary. This effectively prevents the ball 11 from falling off. In the embodiment shown in FIG. 1, the tip end of the sleeve 7 has an inner tapered wall 7g, but the sleeve 7 is not limited to this, and may be a parallel wall substantially parallel to the axial direction. Furthermore, a locking convex portion 6C that engages with the engagement recess 4e of the tip receiving portion 4 may be provided protrudingly on the rear end portion of the lead chuck 6 as shown in FIG. Note that the concave and convex portions may be reversed. These uneven portions 4e and 6c prevent the lead chuck 6 and the tip receiving portion 4 from instantaneously separating when the knock is released, thereby preventing the core feeding operation from becoming insufficient. That is, during the knocking operation, the reed chuck 6 is pressed by the tip receiving part 4 and moves forward, pushing the rear end of a movable cylinder 22 (described later) forward, and this movable cylinder 22 pushes the slider 16 forward and moves forward. It abuts against the rear end of 21. Thereafter, the lead chuck 6 is released and moved forward due to the engagement between the tip hole 4a of the tip receiving part 4 and the rear end of the lead chuck 6, thereby feeding the lead. Here, even immediately after the knock is released, the concave portion 4e and the convex portion 6c
That is, the outer stepped portion 7j of the sleeve 7 retreats and engages with the inner stepped portion 15a of the middle frame 15 until it comes into contact with the inner stepped portion 15a of the middle frame 15. During this time, the lead chuck 6 is released and the lead is smoothly fed. In this embodiment, the lead chuck 6 is divided into two parts, but it may be divided into three or more parts, or it may be formed as a single piece. Furthermore, in order to prevent the lead chuck 6 from shifting in the axial direction, it is preferable to form a concave-convex engaging portion or a jagged edge to prevent slippage in the mutual contact portion. Further, a part of the diameter of the lead chuck 6 is very close to the inner diameter of the middle frame 15, and the rear end of the first elastic body 12 is securely locked by the locking step 6a of the lead chuck 6. Therefore, the lead chuck 6 is reliably prevented from shaking or shifting in the vertical and horizontal directions. Also,
The ball holding portion 10 of the lead chuck 6 simply holds the ball 1.
The hole may hold the ball 11, but the ball 11 may be housed and held so that the ball 11 does not fall out. Note that the ball 11 is rotatable within the ball holding section 10. Further, the first elastic body 12 is a second elastic body 1 which will be described later.
It has a weaker elasticity than 3. The core delivery mechanism 5 described above is almost entirely housed in the middle frame 15. The middle frame 15 is disposed within the outer cylinder 1 so as to be slidable in the axial direction, and is urged forward by a third elastic body 17. And, at the tip of this middle frame 15,
The front tube 9 is provided with an inner step 15a on the inner wall and an outer step 15b on the outer periphery. A distance (c) is provided between the tip tube 9 and the tip of the sleeve 7, as shown in the first figure. This distance i! i (C)
As will be described later, corresponds to the amount of core feeding during the core feeding operation by rear end knocking. Here, the front tube 9 is fitted and engaged with the tip of the middle frame 15, and as described later, comes into contact with the tip of the advancing sleeve 7, has the function of stopping the sleeve 7, and moves the movable tube 22 into a predetermined fit. is held by pressure and abuts against the rear end of the outer locking step portion 22a,
Any material may be used as long as it has the function of stopping the movable tube 22 at the retreated position and fulfills these functions. As shown in the first figure, a movable cylinder 22 having an outer diameter approximately equal to the inner diameter of the inner locking step 9a of the front cylinder 9 is fitted so as to be slidable in the axial direction. At the tip of the movable barrel 22, as shown in FIG.
This outer locking step portion 22a is fitted to the inner circumferential surface of the front cylinder 9 so as to be slidable in the axial direction with a predetermined fitting pressure (frictional resistance). In order to maintain a predetermined fitting pressure with the front cylinder 9 and to ensure sliding in the axial direction, a slit 7) may be applied as necessary.
22b is formed. As shown in FIG. 13(a), the movable barrel 22 has an outer locking step 22a at the rear end of the inner locking step 9 of the front tube 9.
The function is to abut the front end of the slider 16 to restrict the backward movement of the slider 16 to the locked state (stop at the locked position), which will be described later. Move forward against the slider 1
6 and functions to release the locked state. Here, the fitting pressure between the movable cylinder 22 and the front cylinder 9 (for example, 40
0g±50g) is smaller than the elastic force of the third elastic body 17 (for example, 500 to 550g), and conversely, the engagement pressure between the projection 19b of the slider 16 and the inner wall annular projection 21a of the receiving part 21 (for example, 200g±50g). Therefore, as will be described later, the slider 16 locked by the inner wall annular protrusion 21a is unlocked by the pressing force of the movable cylinder 22 that is biased and moved by the third elastic body 17. Furthermore, the inner stepped portion 15a of the middle frame 15 engages with the outer stepped portion 7j of the sleeve 7 during writing. Therefore, the sleeve 7 has a third elastic body 1 that resists the writing pressure.
It is pressed forward by the middle frame 15, which is urged forward by the inner frame 15. The third elastic body 17 performs the following three functions. ■A function to prevent core pipe 3 from rattling. ■
The biasing force of this third elastic body 17 is stronger than normal writing pressure, but it has a cushion function that causes the middle frame 15 to retract in the event that excessive writing pressure is applied to the lead 14 during writing. ■ Core pipe 3
When an eraser (not shown) is provided at the rear end of the eraser, this function is to support the eraser when the eraser is used. It should be noted that the third elastic body 17 is subjected to a force in a compressive direction by the middle frame 15 that is moved backward by a knock at the tip during a core feeding operation, which will be described later. Here, the eraser support function of urging the core pipe 3 backward is performed with a predetermined strong urging force, and
In order to perform the tip knock lightly and smoothly, it is desirable to use a predetermined weak urging force that urges the middle frame 15 forward. Therefore, as shown in FIG. 14, the number of turns of the third elastic body 15 is changed between the front side and the rear side, and its approximately center portion is brought into contact with the inner wall of the outer cylinder l, thereby applying a biasing force toward the front side. If it is weak, it is better to increase the biasing force toward the rear side. In addition, as shown in Figure 15, a telescopic piece 4f that tries to expand outward is formed on a part of the outer periphery of the tip receiving part 4, and the rearward movement of the tip receiving part 4 is caused by friction with the inner wall of the outer cylinder. A predetermined reaction force may be applied. Further, a distance (d) is provided between the outer step portion 15b of the middle frame 15 and the stopper step portion 1a of the outer cylinder 1. Therefore, the maximum retreat distance of the middle frame 15 is
has been regulated. A slider 16 that is movable in the axial direction is arranged inside the tip 2. The slider 16 includes a slider main body 19 mounted around a slide pipe 18 as shown in the first diagram, and a friction applying member that is fitted inside the slider main body 19 and applies a predetermined frictional force to the core 14. 20. The backward friction force (described later) exerted by this friction imparting member 2o on the core 14 is 2
0-30g, above 1. It is larger than the elastic force of the second elastic body 12 , 13 and smaller than the elastic force of the third elastic body 17 and the fitting pressure of the movable cylinder 22 . The slider 16 is urged forward by the second elastic body 13 whose rear end is engaged with a receiving portion 21 that is fixed to the tip 2. Here, the friction applying member 20 applies a predetermined frictional force to the core 14 as shown in FIG. It is larger than the elastic force of the body 12 and slightly larger than the elastic force of the second elastic body 13. Furthermore, the friction imparting member 20 has a friction imparting portion 20a for imparting a predetermined frictional force to the core 14. This friction applying part 20a
is formed at the tip of the friction imparting member 20 to be curved in the direction of diameter reduction, and is formed at the distal end of the second friction imparting hole 20b, and the tapered shape is formed at the distal end of the second friction imparting hole 20b so that the diameter gradually increases on the distal end side. It has secondary friction applying holes 2°C. This friction applying hole 2°a is formed when the core 14 moves forward (arrow (A)).
direction), there is no large deformation and a frictional force (hereinafter referred to as forward frictional force) is applied to the core 14 only by the negative friction applying hole 20b. On the other hand, when the core 14 moves backward (in the direction of arrow (b)),
The friction applying portion 20a is deformed, and the secondary friction applying hole 20c becomes substantially flush with the primary friction applying hole 20b, so that the contact area with the core 14 becomes the total area of both holes 20b and 20C. Therefore, as described later, the friction applying section 20a can smoothly move the advancing core 14;
The slider 16 is formed to apply a large frictional force (hereinafter referred to as a backward frictional force) so that it cannot easily retreat. As in, the receiving part 21
A protrusion 19b that engages with the inner wall annular protrusion 21a is provided. Here, on the side of this slider body 19,
A slit S is formed. Next, the core feeding operation of this invention will be explained. This core feeding operation can be performed in the following three ways. (11) First, the first means is a normal method performed by knocking the rear end of the core pipe 3. In other words, the sleeve 7 engaged with the locking receiver 4 is It moves forward together with the pipe 3, etc., feeds the core until it comes into contact with the rear end of the front tube 9, and then stops.That is, (a) the slider 16 is not locked to the receiving part 21, as will be described later. In the case (see Figure 17),
The core feed is performed as usual by the rear end knock. (b) On the other hand, the slider 16 is connected to the annular protrusion 21 of the receiving portion 21
If it is locked by a (see Figs. 1 and 18), the above-mentioned rear end knock causes the above-mentioned
Until the tip of the sleeve 7 comes into contact with the rear end of the front tube 9 (
During the distance (C)) and (A), core feeding is performed in the same manner, and then the reed chuck 6 moves forward to press the movable cylinder 22 and at the same time press the slider 16 forward. As a result, the slider 16 is moved to the annular protrusion 21a of the receiving portion 21.
overcome and be unlocked. Thereafter, the slider pipe 18 is urged forward by the second elastic body 13 and protrudes from the tip 2 . In this process, the core 14 supported by the backward frictional force of the friction applying member 20 is pulled forward from the lead chuck 6 and moves forward together with the slider 16. Therefore, as shown in Figure 19, the core 14 is connected to the slider pipe 1.
8, it always protrudes by a distance (c) suitable for writing. As mentioned above, by knocking the rear end of the slider 16,
The lock release operation and the lead feeding operation can be performed simultaneously, and the state in which the lead 14 protrudes from the slider pipe 18 by a distance (c) suitable for writing can be ensured. Therefore, it is possible to write while visually checking the lead 14. ■As a second method, by interrupting writing,
Lead feeding operation can be performed automatically. That is, writing is normally performed with the lead 14 protruding from the slide pipe 18 by a predetermined amount X, as shown in FIG. As the writing progresses, the lead 14 gradually wears out and becomes flush with the tip of the slide pipe 18, as shown in Figure 17. Even in this state, the slider 16
can move backward against the biasing force of the second elastic body 13, so that the distance (f) until the rear end of the slider 16 contacts the movable tube 22 is further reduced to the maximum distance (f). 〈(
e). (see FIG. 17) is possible. By the way, the amount of wear of the lead 14 due to writing is the retreat distance (f)
It takes a very long time to write. By the way, with normal adult pen pressure, density HB, lead diameter 0.5
When writing a single kanji character on high-quality paper using an M mechanical pencil, the amount of wear on the lead is only about 0.01 m■. Therefore, it is usually possible that continuous writing is performed until the slider 16 retreats by the retracting distance (f), and it is considered that writing is always interrupted, such as when taking a break from writing. For example, assume that writing is interrupted in the state shown in FIG. 22 and the tip of the slide pipe 18 is removed from the paper surface. As a result, the slider 16 is moved forward by the elastic force of the second elastic body 13, and the core 14 is also pulled in the forward direction together with the slider 16 by a predetermined frictional force from the friction applying member 20. On the other hand, since the chuck tightening force of the lead chuck 6 on which the core 14 is sprayed is applied by the first elastic body 12 which is weaker than the second elastic body 13, the above-mentioned tension in the forward direction of the core 14 is applied. The force compresses it and allows the entire reed chuck 6 to advance. During this forward movement, the head of the reed chuck 6 is moved so that the pole 11 is attached to the tapered inner wall 7g of the sleeve 7.
As the lead chuck 6 rolls into contact and moves forward, the blowing force of the lead chuck 6 weakens, and the lead 14 is fed out. Through this series of operations, the state shown in Figure 17 is restored, the lead feeding operation is automatically performed, and writing becomes possible.
Continuous writing is possible up to the maximum retreat distance (f). (3) The third means is to send out the core by knocking the tip of the slider 16 against the paper surface. There are two types of this tip knock, and their effects are different, so each case will be explained separately. (a) The first tip knock is performed when the core 14 does not protrude from the tip of the slide pipe 18, as shown in Figure 17, and by knocking the tip, the distance from the slide pipe 18 is always if, 1 ( The state shown in FIG. 20 (X=(f)) in which the length core 14 protrudes is obtained. That is, due to the tip knock, the lead chuck 6 retreats with the lead 14 bitten as shown in Figure 21, and
The slider 16 also moves back. The amount of retraction of both is the same, and the convex portion 19a of the slider 16 is pushed back as much as possible by the receiving portion 2.
It is possible to reach a distance Mlt(e) that abuts the tip of 1. In addition, between distance (e) and distance (c), (e) < (d
). When retracting the lead chuck 6, the distance a shown in the first diagram is
There is the above-mentioned relationship a>d between and d, and since the rear end of the lead chuck 6 cannot come into contact with the tip receiving part 4, the lead 14 is always held in the sprayed state. . Then, as the lead chuck 6 retreats, the inner and outer thigh portions 15
The middle frame 15 and the front tube 9 are moved rearward against the biasing force of the third elastic body 17 via a and 7j. On the other hand, upon retraction of the slider 16, the distance (a). Between (e) and (g), (a) > (e) > (g
) is established. Here, distance! (g) refers to the distance between the inner wall annular projection 21a and the front side of the projection 19b. Therefore, in the process of the slider 16 retreating by the maximum retreat distance (e), the protrusion 19b of the slider body 19 first climbs over the inner wall annular portion 21a, and then the rear end of the slider body 19 protrudes from the rear end of the receiving portion 21. I will do it. here,
The middle frame 15 and the core delivery mechanism 5 are moved back the same distance as the slider body 19 while the core 14 is being bitten. Therefore, a distance () is maintained between the rear end of the slider body 19 and the leading tube 9.Next, the leading end of the slider 16 is removed from the plane of the paper. The lead feeding mechanism 5 and the middle frame 15 move forward mainly by the third elastic body 17 until the tip tube 9 comes into contact with the stepped portion 2a of the tip tool 2. On the other hand, the slider 16 moves forward as shown in the 23rd figure. It is temporarily stopped by the protrusion 19b of the slider 16 that engages with the inner wall annular protrusion 21a.Even when the slider 16 is temporarily stopped, the core delivery mechanism 5 continues to move forward while biting the core 14 as described above. The core 14 is pushed into the friction imparting member 20 of the slider 16 by the length (f).Then, the movable cylinder 22 pressed by the third elastic body 17 comes into contact with the rear end of the slider body 19, and the above-mentioned temporary stop occurs. At this moment, the slider 16 releases the second elastic body 1.
At the same time, the lead 14 held by the reed chuck 6 is pulled out by the friction applying member 20 (backward friction force) in the slider 16, and the slider 16 is restored to its original position. 14 projects from the tip of the slider pipe 18 by a length (f). (b) Next, the second tip knock is performed with the core 14 protruding from the tip of the slide pipe 18 as shown in FIG. 20. In this case, the protrusion 1x and the distance (d) − distance (g) −
If there is a relationship between As an example, we will explain by substituting specific numerical values. For example, (f) = 0°8 @Drama,
(g) =1. 3+w praise,
(d) =1. 1 mm, X = 0.3 frames (< (d) - (g) = 0.4111). When the tip is knocked in this state, first, only the lead delivery mechanism 5 and the middle frame 15 move back together with the lead 14 up to the retreat distance X. Thereafter, the slider 16 and the movable cylinder 22 move back together with the lead delivery mechanism 5 and the middle frame 15 while the lead 14 is bitten in the same way as in the first tip knock. Therefore, lead chuck 6
The retraction amount is larger than that of the slider 16 by X=0.3 mm. Therefore, the retractable distance of the slider 16 is determined by the amount of retraction on the stopper step 1a. 11 middle frame 1
regulated by 5, remaining (d) - (g) = 1.7u+
-1,3m prize-〇, only 4 can be retreated. This is because the slider 16, the middle frame 15, and the lead delivery mechanism 5 must move back as one while the lead 14 is being bitten by the lead chuck 6. During the retreat process, the protrusion 19b climbs over the inner wall annular protrusion 21a of the receiving portion 21. Next, when the slider 16 is pressed and released from the zero paper surface, the core delivery mechanism 5
moves forward with the core 14 bitten. Thereafter, the core 14 protrudes from the tip of the slide pipe 18 by a length (f) in exactly the same way as the first tip knock. On the other hand, when X>(d)(g)=0.4+im, the slider 16 cannot retreat until it can engage with the inner wall annular protrusion 21a due to the middle frame 15 whose rear end is regulated by the stopper step 1a. . Therefore, a situation in which the slider 16 engages with the protrusion 21a of the receiving portion 21 and is temporarily stopped cannot occur, so the amount of protrusion as described above is not adjusted. In other words, no matter how many times the tip is knocked, the tip knock without core feeding is repeated, so the core 14 will always protrude at the same protrusion 1x. This means that the lead 14 suitable for writing is the slider pipe 18.
If it protrudes from the core 14, the tip knocks the core 14.
0.3 to prevent the lead from breaking when writing.
Dragon, the distance (d) in advance according to the core diameter of 0.5 mm,
It is only necessary to design the relationship (g), and the structure is such that an easy-to-use and economical mechanical pencil can be provided. Next, a description will be given of when the writing instrument is not in use. Knock the rear end of the lead vibrator 13 from the unlocked state (in this case, the lead chuck 6 has released the lead 14. Therefore, unlike the tip knock described above, the inner frame 15 and the lead delivery mechanism 5 ), and press the slider pipe 18 against the paper surface etc., and move the slider 16 to the end tool 2.
Lock and store. That is, the slider 16 retreats by the above operation, and in the retreating process pushes the movable cylinder 22 backward. Here, since the pressure of the slider pipe 18 against the surface of the paper is greater than the fitting pressure between the movable tube 22 and the front tube 9, the movable tube 22
is pushed backward as shown in Figure 18. At this time, the third
Since the elastic body 17 is designed to be larger than the fitting pressure between the front tube 9 and the movable tube 22, the lead delivery mechanism 5 does not move, so that lock scraping can be performed smoothly. In this process, the protrusion 19b of the slider 16 rides over the annular protrusion 21a of the receiving part 21 and is locked. With this, slider 1
6 is locked immovably in the locking position. Due to this lock, the slider 16 will not be unlocked even if some external force is applied, and the slider 16 will not be unlocked even if some external force is applied.
6 will not cause an unexpected decrease in core protrusion. Then, this lock is simply released by knocking at the rear end of the core vibrator 3, as described in the above-mentioned first means.

【Effect of the invention】

As described above, according to the present invention, the lead chuck is tightened by the sleeve, the sleeve is urged forward by the middle frame, and the slider is locked at a predetermined time by the front barrel, so that the internal structure is improved. It can be simplified, and the core feeding operation can be reduced to 3 times.
It can be done in the same way as described above, and in addition, the effect of the previous application is that when the lead is sent out using the knock at the tip, a constant amount of protrusion can always be obtained, even if the lead does not protrude, or even if it protrudes excessively by more than a predetermined amount. In addition, the slider can be locked in the retracted position by the notch at the tip of the slider, which eliminates the problem of the slider moving unsteadily on its own when the writing instrument is not in use, causing the lead to be inadvertently delivered.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, FIG. 2 is a plan view showing the state of engagement between the sleeve and the tip receiving portion, FIG. 3 is a partial vertical cross-sectional view of the lead chuck, and FIG. The figure is the same plan view,
Figure 5 is a sectional view taken along the line X-X in Figure 4, and Figure 6 is a
-Y line sectional view, FIG. 7 is a plan view of the tooth portion for core biting, FIG. 8 is a sectional view of the tooth portion, FIGS. 9 and 10 are plan views of other embodiments of the tooth portion, and FIG. 15 is a front view of another embodiment of the tip receiving portion, FIG. 16 is a sectional view of the friction imparting member, and FIGS. 17 to 23. is an explanatory diagram of the core feeding operation. 1 is an outer cylinder, 3 is a core pipe, 6 is a lead chuck, 7 is a sleeve, 9 is a tip cylinder, 12, 13.17 is an elastic body, 14
is the core, 15 is the middle frame, 16 is the slider, 19b, 21a
2 is a locking means, and 22 is a movable cylinder.

Claims (1)

[Claims] A core pipe (3) is housed inside the outer cylinder (1) so as to be slidable in the axial direction, and a core pipe (3) is arranged at the distal end of the core pipe (3) to allow the core (14) to move forward, but not to retreat. A lead chuck (6) for attaching a core to prevent it, and this lead chuck (6)
The sleeve (7) fitted on the head of the
) and the lead chuck (6), a chuck tightening elastic body (12), a cushioning elastic body (17) that urges the sleeve (7) forward, and the lead chuck (6). It is slidably arranged on the tip side of the lead chuck (6),
Elastic body (13) with a larger elasticity coefficient than the elastic body (12)
) is urged forward by the slider (16), and when the slider (16) is in the retreated position, the elastic body (13
), locking means (19b), (21a) that releasably locks with an engagement force greater than the elastic force of the inner frame (15); The slider (16) is fitted to be slidable in the axial direction with a predetermined friction pressure.
The engaging means (19b), (21a)
A mechanical pencil equipped with a movable barrel (22) that releases the lock.