JP2009269335A - Mechanical pencil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce sound of a mechanical pencil in knocking operation. <P>SOLUTION: The mechanical pencil includes a lead chuck sending out a lead, and a chuck ring fastening the lead chuck, and a sound absorbing member is disposed at a rear part of the chuck ring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mechanical pencil used as a writing instrument, and more particularly to a mechanical pencil that reduces knock operation noise generated from a lead feeding mechanism during a knock operation.

  In general, a knock-type mechanical pencil equipped with a lead feeding mechanism has a shaft cylinder gripped by the user's hand, a tip attached to the tip of the axle, a tip pipe attached to the tip of the tip, and a shaft cylinder. A lead tank that is arranged to move back and forth inside the lead tank, accommodates a plurality of writing leads, a lead chuck that is connected to the tip of the lead tank and grips the writing lead from the lead tank, and tightens the lead chuck to the lead chuck. By a chuck ring that opens and closes the lead chuck by moving in the front-rear direction, a spring that biases the lead tank and lead chuck backward, a drive mechanism such as a rear end knock type or side knock type that drives the lead tank forward It is configured.

  On the other hand, a mechanical pencil is also known in which molybdenum disulfide is applied to the contact portion between the lead chuck and the chuck ring to prevent wear of the contact portion and to generate a comfortable sound (for example, see Patent Document 1). ).

Japanese Utility Model Publication No.3-3435

  A user of a conventional mechanical pencil feels comfortably knocking sound generated when operating the lead feeding mechanism to feed out the writing lead, but may find it troublesome in a quiet place. Moreover, when many students generate knock sounds in one classroom, it can be easily predicted that the knock sounds will become noise.

  In view of the need for a mechanical pencil that suppresses the generation of sound during a knock operation, the present inventor provides a mechanical pencil that reduces the knock operation noise generated from the lead feeding mechanism during the knock operation. Is.

  The mechanical pencil according to the present invention includes a lead chuck for performing a lead feeding operation and a chuck ring for tightening the lead chuck, and a sound absorbing member is disposed at a rear position of the chuck ring.

  In the mechanical pencil according to the present invention, a sound absorbing member is disposed between the chuck ring and a ring receiving portion provided on the sleeve or the shaft tube.

  The mechanical pencil according to the present invention has a sound absorbing member formed integrally with a chuck ring.

In the mechanical pencil according to the present invention, the sound absorbing member is a ring receiving portion provided on a sleeve or a shaft tube.

  According to this invention, since the sound absorbing member provided at the rear position of the chuck ring absorbs the impact force received from the chuck ring that is flipped back at the time of the knock operation, noise generated by the knock operation can be reduced. In addition, it is possible to prevent breakage of the color core or the like due to an impact, and it is possible to improve the durability of the core feeding mechanism.

Embodiment 1 FIG.
FIG. 1 shows a cross-sectional view of a main part of a writing state of a mechanical pencil according to Embodiment 1 of the present invention.
The mechanical pencil includes a shaft cylinder 2 having a through-hole 1, a core feeding mechanism 3 disposed inside the shaft cylinder 2, a grip cover 4 mounted on the outer peripheral surface of the shaft cylinder 2, and a shaft cylinder 2. A tip tool 6 that is detachably fixed to the distal end side and has a through hole 5 and a slider set 7 that is movably disposed inside the tip tool 6 are provided.
In addition, with respect to the axial direction of the mechanical pencil, the tip 6 side is referred to as “front”, and the opposite side is referred to as “rear”.

The lead feeding mechanism 3 includes a lead tank 8 slidably provided in the axial direction inside the shaft tube 2, a lead chuck 9 fixed to the lead tank 8, and opening and closing the lead chuck 9. The chuck ring 10 for feeding the lead L, the sleeve (cushion sleeve) 11 disposed behind the chuck ring 10 in a form in which the lead tank 8 and the lead chuck 9 are housed, and the sleeve 11 And a lead 12 and a spring 12 (biasing means) for biasing the lead tank 8 and the lead chuck 9 backward.
A rear end knock type driving mechanism (not shown) is connected to the rear of the lead tank 8.

The shaft cylinder 2 has a screw portion 2A for releasably screwing the tip tool 6 and an inward annular protrusion 2B for locking and fixing the rear end portion of the sleeve 11.
The tip 6 includes a grip cover locking step portion 6A and a screw portion 6B that is detachably screwed with the shaft cylinder 2, and a step portion 6C that houses the sleeve 11 and locks the tip of the sleeve 11. 1 cylinder part 6D, 2nd cylinder part 6E which is formed smaller diameter than this 1st cylinder part 6D, slidably accommodates the lead chuck 9, and smaller diameter than this 2nd cylinder part 6E, slider set 7 And a third cylindrical portion 6F that slidably accommodates the lead chuck 9.

Next, each component of the lead feeding mechanism 3 will be described below.
The lead chuck 9 includes a rear fixing portion 9A that is fixed to the tip of the lead tank 8, a lead hole 9B that accommodates the lead L so as to be movable in the front-rear direction, and a head that is clamped by the chuck ring 10 and grips the lead L. 9C and a plurality of slits 9D that can be moved in the axial direction in order to enable the core L to be gripped by the head 9C.

The head portion 9C of the lead chuck 9 has an outer peripheral surface portion 9C1 formed larger than the inner diameter of the chuck ring 10, and an inclined outer peripheral surface portion 9C2 formed behind the outer peripheral surface portion 9C2.
The head 9C is tightened when engaged with the chuck ring 10 and is configured to grip the core L. On the other hand, when not engaged with the chuck ring 10, the head 9C is released and expanded to expand the diameter of the core L. Is configured to open. That is, the lead L 9 is extended by opening and closing the head 9 </ b> C of the lead chuck 9 with the chuck ring 10.

The lead chuck 9 can be made of plastic or metal, but is not limited to these materials. If the lead chuck 9 can be opened and closed by the chuck ring 10 and the lead L can be sent out, Any material, shape, etc. may be used.

  The chuck ring 10 is formed in a cylindrical shape having a smaller diameter than the outer peripheral surface portion 9C1 of the head portion 9C of the lead chuck 9. Usually, the head portion 9C of the lead chuck 9 is provided by a spring 12 that urges the chuck ring 10 forward. Tighten. On the other hand, at the time of knocking operation, the chuck ring 10 moves forward together with the head portion 9C of the lead chuck 9, and the tip of the chuck ring 10 comes into contact with the step portion 6E1 of the second cylindrical portion 6E inside the tip 6 so that the head portion 9C of the lead chuck 9 The tightening is released, and the head portion 9C is configured to open the lead L.

The chuck ring 10 can be made of plastic or metal, but is not limited to these materials. If the lead chuck 9 can be opened and closed to perform the feeding operation of the lead L, the chuck ring 10 can be made of plastic or metal. Any material, shape, etc. may be used.

The sleeve 11 engages the tip of the spring 12 and the back side of the chuck ring 10 to restrict the rearward movement of the chuck ring 10 and an inner annular portion 11A having a cushion function. Have
The sleeve 11 can be made of plastic or metal, but the material is not limited.

Here, as shown in FIGS. 1 to 3, an absorbing sound member 13, which is a main part of the present invention, is disposed on the front side of the inner annular portion 11 </ b> A of the sleeve 11, and the absorbing sound member 13 is the chuck ring 10. And the sleeve 11.

The absorbing sound member 13 prevents the chuck ring 10 from coming into direct contact with the sleeve 11 to give an impact and absorbs an impact force, and absorbs a sound generated when the chuck ring 10 receives an impact. When an external force such as excessive writing pressure is applied to the core L, it has a cushion function that absorbs the external force and prevents breakage.

In order to achieve these functions, the absorbing sound member 13 is made of, for example, a soft material having elasticity such as rubber or soft synthetic resin. However, the sound absorbing member 13 is not limited to these materials, and may be any material, shape, etc. as long as the above functions can be exhibited.

4 is a front view of the sound absorbing member 13, FIG. 5 is a cross sectional view of the chuck ring 10, and FIG. 6 is a cross sectional view showing the relationship between the position and shape of the chuck ring 10, the sound absorbing member 13 and the sleeve 11.

The absorbing sound member 13 according to the first embodiment is formed in a ring shape as shown in FIG. Here, as shown in FIGS. 1, 2, 3, and 6, the outer diameter of the sound absorbing member 13 is formed to be slightly smaller than the inner diameter on the distal end side of the sleeve 11. On the other hand, the inner diameter of the sound absorbing member 13 is formed to be substantially the same as the inner diameter of the inner annular portion 11A of the sleeve 11.
Therefore, the sound absorbing member 13 is formed in a structure that can be entirely accommodated within the inner diameter of the distal end side of the sleeve 11 such that the back side thereof is in contact with the inner annular portion 11 </ b> A of the sleeve 11.

With the shape and configuration as described above, the absorbing sound member 13 receives an impact received from the chuck ring 10 without bringing the chuck ring 10 that is flipped back at the time of the knock operation into contact with the parts of the core feeding mechanism 3 such as the sleeve 11. Absorbs force and absorbs sound efficiently.
The absorbing sound member 13 does not obstruct the lead feeding of the lead feeding mechanism 3 at all.

The structure of the sound absorbing member 13 will be described in more detail. As shown in FIGS. 4 and 6, the chuck ring contact surface 13A formed of a shape and material capable of absorbing the impact force and generated sound of the chuck ring 10; And a sleeve contact surface 13B formed on a side different from the chuck ring contact surface 13A, and is disposed on the rear side of the chuck ring 10.
The chuck ring contact surface 13A is formed in a sufficiently large shape capable of reliably contacting the entire rear surface of the chuck ring 10 and absorbing the impact force. With the function, it is possible to absorb the impact force received from the chuck ring 10 that has been blown backward without contacting the core feeding mechanism 3 such as the sleeve 11 and other parts, and to efficiently absorb the generated sound.

In the first embodiment, the absorbing sound member 13 can be formed integrally with the sleeve 11. In this case, the absorbing sound member 13 may be formed of a soft material and the sleeve 11 may be formed of a hard material, and a two-color molded structure may be used in order to facilitate recognition of both portions.

  The slider set 7 has a front tip 7A and a rear core holding member 7B, and the slider L holds the core L with a certain frictional resistance.

Next, the operation of the mechanical pencil in Embodiment 1 of the present invention will be described.
When the mechanical pencil user pushes the lead tank 8 forward and performs a knocking operation, the lead tank 8 and the lead chuck 9 integrated with the lead tank 8 advance against the biasing force of the spring 12 as shown in FIG.
As a result, the chuck ring 10 moves forward with the lead chuck 9 tightened by the frictional force with the outer peripheral surface portion 9C1 of the lead chuck 9, contacts the second step portion 6E1 of the tip 6 and stops its movement. . On the other hand, since the lead chuck 9 continues to advance, the lead chuck 9 is released from tightening by the chuck ring 10.

By this releasing operation, the leading end side of the lead chuck 9 is expanded, the grip on the lead L is loosened, and the lead L is released. At this time, as shown in FIGS. 2 to 3, the inclined outer peripheral surface portion 9C2 of the lead chuck 9 is also expanded. The chuck ring 10 is rebounded back by the elastic force from the inclined outer peripheral surface portion 9C2 generated at the time of the expansion.
That is, due to the spring property of the lead chuck 9 itself when the lead chuck 9 is opened, the chuck ring 10 is flipped backward, and as shown in FIG. 3, the sleeve 11 or the shaft cylinder 2 where the chuck ring 10 is located rearward, etc. Touching and giving impact force. Here, the absorbing sound member 13 is formed in a shape that can reliably contact the entire rear side of the chuck ring 10 and is provided between the chuck ring 10 and the sleeve 11, so that it is flipped back. First, the chuck ring 10 does not come into direct contact with the sleeve 11 or other components, but first comes into contact with the absorbing sound member 13, and at that time, the impact force is buffered and generated when the chuck ring 10 comes into contact. It is configured to absorb sound.

  Thereafter, when the user finishes the knocking operation, as shown in FIGS. 3 to 1, the lead tank 8 and the lead chuck 9 are gradually moved backward by the biasing force of the spring 12. During this time, the slider set 7 holds the core L with frictional resistance and keeps it in the advanced position. Further, as shown in FIG. 1, the head portion 9 </ b> C of the lead chuck 9 is again tightened by the chuck ring 10, and the lead L is gripped so that writing can be performed.

  As described above, in the mechanical pencil according to the first embodiment, since the sound absorbing member 13 is provided between the chuck ring 10 and the sleeve 11, it is flipped backward by the spring property of the lead chuck 9 itself during the knocking operation. The chuck ring 10 that has been skipped does not directly contact the sleeve 11 and other components, but first contacts the sound absorbing member 13, and the sound absorbing member 13 absorbs the impact force and generates at that time. Since the sound is absorbed, it is possible to reduce the sound generated during the knocking operation.

Further, since the impact force when the lead chuck 9 contacts the absorbing sound member 13 is reduced, the impact force applied to other mechanisms, for example, a mechanism for preventing the core L from being damaged can be reduced. As a result, it is possible to improve the breakage of the lead having a low strength, such as a color lead, and the durability of the lead feeding mechanism.

Furthermore, since the sound absorbing member 13 is made of, for example, a soft material having elasticity such as rubber or soft synthetic resin, the sound absorbing member 13 itself has an external force absorbing function or a cushion function. Therefore, at the time of writing shown in FIG. Even if an excessive force such as excessive writing pressure acts on the core L, the cushion function is exhibited and breakage can be prevented. That is, even if a sleeve having no cushion function or a cushion spring is not provided behind the sleeve, the sound absorbing member 13 itself functions as a cushion function part, and can be reliably prevented from being broken.

Embodiment 2. FIG.
7 is a cross-sectional view of the chuck ring 10 and the sound absorbing member 13 according to the second embodiment of the present invention, and FIG. 8 shows the positions of the chuck ring 10, the sound absorbing member 13 and the sleeve 11 according to the second embodiment of the present invention. It is sectional drawing which shows the relationship of a shape.
Hereinafter, the same reference numerals are given to the same parts in FIG. The mechanical pencil in the second embodiment is different from the mechanical pencil in the first embodiment in that the absorption sound member 13 is attached to the chuck ring 10 and the shape of the sleeve 11 is changed correspondingly. Is different.

  That is, the sound absorbing member 13 is formed of a shape and material that can absorb the impact force of the chuck ring 10 and the sound generated when the shock is received, similar to the sound absorbing member 13 in the first embodiment, and has a cylindrical shape. A chuck ring contact surface 13A and a sleeve contact surface 13B formed on a side different from the chuck ring contact surface 13A are provided.

In particular, the cylindrical chuck ring contact surface 13A is integrally formed on the outer peripheral surface of the rear portion of the chuck ring 10 and is formed in a shape covering the entire rear side of the chuck ring 10, so that the sleeve 11 or the like The impact force received from the chuck ring 10 can be absorbed and the generated sound can be reduced without contacting the parts of the lead feeding mechanism 3.
It should be noted that the integral relationship between the sound absorbing member 13 and the chuck ring 10 is that the two are formed separately and are detachably integrated, or the two are integrally formed when they are fixed or engaged. The case where it is performed etc. can be considered and can be selected as needed.

  In the mechanical pencil according to the second embodiment, the rear end surface of the main body portion of the sound absorbing member 13 contacts the front surface of the inner annular portion 11A of the sleeve 11 during the knocking operation. Therefore, the mechanical pencil in the second embodiment can obtain the same effects as those in the first embodiment.

Embodiment 3 FIG.
9 is a sectional view of the chuck ring 10 and the sound absorbing member 13 according to Embodiment 3 of the present invention, and FIG. 10 shows the positions of the chuck ring 10, the sound absorbing member 13 and the sleeve 11 according to Embodiment 3 of the present invention. It is sectional drawing which shows the relationship of a shape.
The sound absorbing member 13 according to the third embodiment is formed in a ring shape, and is disposed between the chuck ring 10 and the sleeve 11 so as to be freely movable.
In the third embodiment, the same effect can be obtained in spite of the simpler structure than the first embodiment.

In particular, the sound absorbing member 13 is formed in a ring shape having a chuck ring contact surface 13A and a sleeve contact surface 13B formed on a side different from the chuck ring contact surface 13A, and the chuck ring 10 and the sleeve 11 are formed. It is arrange | positioned so that floating is possible. Accordingly, the chuck ring 10 that has been flipped back by the spring property of the lead chuck 9 itself during the knocking operation does not directly contact the sleeve 11 and other parts, but first makes soft contact with the absorbing sound member 13. The absorbing sound member 13 cushions the impact force between the chuck ring 10 and the sleeve 11 and absorbs the generated sound at that time, so that the sound during the knocking operation can be reduced.

Here, in the first to third embodiments, the sound absorbing member 13 is disposed between the chuck ring 10 and the sleeve 11 and receives the sleeve contact surface 13B of the sound absorbing member 13 by the sleeve 11. As described above, the sleeve contact surface 13B of the sound absorbing member 13 may be received by a component other than the sleeve 11 as long as the sound absorbing member 13 can exhibit the above functions.

For example, a ring receiving part (not shown) for receiving the chuck ring 10 may be formed in the shaft cylinder 2 and the sound absorbing member 13 may be disposed between the chuck ring 10 and the ring receiving part. The effect similar to the effect in Embodiment 3 from 1 can be acquired.

In the first to third embodiments described above, the sound absorbing member 13 has been described centering on one independent component. However, as described in paragraph [0028], the sound absorbing member 13 is described. May be formed integrally with the sleeve 11, the absorbing sound member 13 may be formed of a soft material, and the sleeve 11 may be formed of a hard material. In addition, for example, a ring that receives the chuck ring 10 formed on the shaft cylinder 2. The receiving part itself may be sufficient.

  Furthermore, although the front surface (collision surface) of each of the sound absorbing member 13 in the first embodiment and the sound absorbing member 13 in the second embodiment is a flat surface, it can be a wavy surface. Further, in the absorbing sound member 13 arranged to be freely movable in the third embodiment, both the front surface and the rear surface can be corrugated. In addition, although the cross-sectional shape of the sound absorbing member 13 is rectangular, in the first and second embodiments, the front surface of the cross-sectional shape, and in the third embodiment, both the front surface and the rear surface are arc-shaped, tapered, or the like. It can be a shape. As a result, the contact area between the lead chuck 9 and the sound absorbing member 13 and the contact area between the sleeve 11 and the sound absorbing member 13 can be reduced to further reduce the generated sound.

Here, in the first to third embodiments, the rear end knock type drive mechanism has been described. However, the principle of the present invention uses other drive mechanisms such as a side knock type, a swing type, and a rotary type. It can also be applied to mechanical pencils.
In the first to third embodiments, the mechanical pencil provided with the sleeve 11 has been described. However, the mechanical pencil provided with the ordinary sleeve 11 can be applied in the same manner, and the same effect can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 3 is a cross-sectional view illustrating a main part of the mechanical pencil in a state where the lead chuck tightening by the chuck ring according to the first embodiment of the present invention is released. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating a main part of a mechanical pencil in a state where a chuck ring according to Embodiment 1 of the present invention is in contact with an absorbing sound member. The front view of the sound absorption member 13 in Embodiment 1 of this invention. 1 is a cross-sectional view of a chuck ring 10 according to Embodiment 1 of the present invention. Sectional drawing which shows the relationship of the position and shape of the chuck ring 10, the absorption sound member 13, and the sleeve 11 concerning Embodiment 1 of this invention. Sectional drawing of the chuck ring 10 and the sound absorption member 13 concerning Embodiment 2 of this invention. Sectional drawing which shows the relationship of the position and shape of the chuck ring 10, the absorption sound member 13, and the sleeve 11 concerning Embodiment 2 of this invention. Sectional drawing of the chuck ring 10 and the sound absorption member 13 concerning Embodiment 3 of this invention. Sectional drawing which shows the relationship of the position and shape of the chuck ring 10, the absorption sound member 13, and the sleeve 11 concerning Embodiment 3 of this invention.

Explanation of symbols

2 Shaft cylinder 3 Core feed mechanism 6 Tip 7 Slider set 8 Core tank 9 Lead chuck 10 Chuck ring 11 Sleeve (cushion sleeve)
12 Spring (biasing means)
13 Absorbing sound member 13A Chuck ring contact surface 13B Sleeve contact surface

Claims (4)

  A mechanical pencil comprising a lead chuck for performing a lead feeding operation and a chuck ring for tightening the lead chuck, wherein a sound absorbing member is disposed at a rear position of the chuck ring.   The mechanical pencil according to claim 1, wherein the sound absorbing member is disposed between the chuck ring and a ring receiving portion provided in a sleeve or a shaft tube.   The mechanical pencil according to claim 1 or 2, wherein the sound absorbing member is formed integrally with the chuck ring.   The mechanical pencil according to claim 1, wherein the sound absorbing member is a ring receiving portion provided on a sleeve or a shaft tube.

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