JP2018108683A - mechanical pencil - Google Patents

Abstract

To provide a mechanical pencil with a simple structure in which a lead is pushed forward by a user pressing the lead strongly against a writing surface at an arbitrary timing according to consumption of the lead at the time of writing. At least a part of a tip member (4) having a slide member (6) inwardly movable is disposed so as to protrude forward from a front end opening of a shaft tube (8). , A first elastic member 22 for elastically projecting the tip member 4 and a second elastic member 21 for elastically projecting the lead feeding mechanism 18 forward, and the shaft cylinder 8 is axially formed on the side surface. The tip member 4 has a protruding portion 20a that is inserted into the guide portion 2a of the shaft tube 8 on the side surface and slides inside the guide portion 2a. The speed at which the tip member 4 moves forward with respect to 8 is configured to be slower than the speed at which the lead feeding mechanism 18 moves forward with respect to the shaft cylinder 8. [Selection] Figure 2

Description

  The present invention relates to a mechanical pencil, and more particularly to a mechanical pencil having a structure in which a certain amount of a lead is drawn out as the lead is worn.

  Conventionally, Patent Document 1 is known as a mechanical pencil that is automatically drawn out by the amount of wear of the core.

  Specifically, in the structure of Patent Document 1, the tip of the core guide pipe comes into contact with the writing surface at the time of writing, the core guide pipe moves backward, the writing is interrupted, and the tip of the core guide pipe is separated from the writing surface. Is. However, in the structure of Patent Document 1, since the lead guide pipe with the lead holder built-in moves forward while holding the lead, the tip of the lead guide pipe contacts the writing surface together with the lead in most writing. The writing feeling was impaired.

As means for solving this problem, Patent Document 2 discloses that the tip of the sliding unit serving as the lead guide does not come into contact with the lead by drawing out the lead by adding and releasing the writing pressure applied to the lead at the time of writing. The constructed automatic feeding type mechanical pencil is described.
In Example 3 of Patent Document 2, there is exemplified an arrangement in which a chuck unit for preventing the retraction of the core and a sliding unit for holding the core are arranged in the shaft cylinder, and writing pressure is applied to the core at the time of writing. When applied, the sliding unit serving as the lead guide moves backward together with the lead, so that the sliding unit does not come into contact with the writing surface and the writing feeling is not impaired. Further, in the structure of Patent Document 2, a cylindrical member having a plurality of sawtooth cam ridges formed in the rear end surface and the tip member of the slide unit and having a projection that engages with the sawtooth cam ridges is provided as a slide unit. By rotating and moving back and forth by the back and forth movement of the cylinder member and making the distance of the back and forth movement of the cylindrical member intermittent, it is configured so that the lead is drawn out once with a plurality of writing pressures, preventing unnecessary feeding of the lead. can do. And with this structure, how many times the sliding unit moves back and forth in response to the use of the mechanical pencil, the hardness and paper quality of the writing core, and the wear of the core due to the writing language, etc. Can be set.

  However, in Patent Document 2, the structure is complicated, and further, the number of forward and backward movements of the sliding unit is 1 depending on the usage of the mechanical pencil, the hardness of the writing core, the paper quality, the wear of the core due to the writing language, etc. Although it can be manufactured by setting whether or not the lead is extended, it cannot respond to changes in the situation after use, so if you use it differently from the setting, the lead will stick out from the tip of the sliding unit when writing As a result, breakage of the lead may occur.

Japanese Utility Model Publication No. 60-21273 International Publication WO2012 / 014832

  The present invention has been invented in view of the above-mentioned problem, and according to consumption of the lead at the time of writing, the user presses the lead against the writing surface at an arbitrary timing so that the lead moves forward. The purpose is to provide a mechanical pencil that is fed out with a simple structure.

The present invention
“1. A shaft cylinder, a core feeding mechanism having a chuck that is disposed in the shaft cylinder and permits the advancement of the core but prevents the backward movement, and a core holding member that holds the core with an appropriate force. A mechanical pencil that feeds the lead forward by pressing the lead backward along the axis;
A tip member in which the core holding member is provided in the shaft tube is disposed so as to move back and forth by projecting the front end from the front end opening of the shaft tube,
The shaft cylinder includes a first elastic member that elastically projects the tip member forward, and a second elastic member that elastically projects the core feeding mechanism forward,
On the side surface of the shaft tube, there is a guide portion inclined with respect to the axial direction,
The side surface of the tip member has a protrusion that is inserted into the guide portion of the shaft tube and moves within the guide portion,
By applying a pressing force that pushes the lead backward to the lead, the lead feeding mechanism and the tip member are moved to the shaft against the resilient force of the first and second resilient members. Retreat against the tube,
A time t1 from when the pressing force is released to the time when the tip member moves forward and returns to the original position, and a time from when the pressing force is released to the time when the lead feeding mechanism moves forward and returns to the original position A mechanical pencil characterized in that t2 satisfies a relationship of t1> t2.
2. The protrusion of the tip member is formed so as to protrude outward from the side surface of the shaft tube,
2. The mechanical pencil according to claim 1, wherein the core is drawn forward by gripping the protruding portion and reciprocatingly moving in the guide portion along the guide portion of the shaft cylinder.
3. A slide member in which the core holding member is provided in the tip member is disposed so as to be movable back and forth by projecting the front end from the tip opening of the tip member,
By stretching a third elastic member between the tip member and the slide member, the slide member is elastically forward,
3. The mechanical pencil according to item 1 or 2, wherein, when writing, the slide member moves backward with respect to the tip member so that the lead is fed forward.
4). A knock body protruding rearward from the rear end opening of the shaft cylinder is provided behind the core feeding mechanism, and the core is fed forward by pushing the knock body forward. The mechanical pencil according to any one of items 1 to 3. Is.

The mechanical pencil of the present invention pushes the lead, which is the tip of writing, against a flat part such as a writing surface, thereby retracting the lead feeding mechanism and the tip member together with the lead with respect to the shaft tube, and separating the lead from the writing surface. When the pressing force to the core is released, the time from when the tip member moves forward to return to the original position is t1, and the time from the lead feeding mechanism to advance to return to the original position is t2, t1 It is important to configure so as to satisfy the relationship of> t2. Then, by setting t1> t2, when the lead is separated from the writing surface, the lead feeding mechanism advances ahead of the tip member and returns to the original position. At this time, the lead held by the chuck is moved to the lead feeding mechanism. Since the force to advance by is higher than the holding force of the lead holding member, the lead is advanced with respect to the tip member. Further, the tip member that moves forward with delay holds the lead by the lead holding member, and the chuck allows the lead to move forward, so that the lead held by the chuck is pulled back and returned to the original position.
For this reason, the mechanical pencil of the present invention can feed the lead forward by pressing the lead backward as the first lead feeding means.

  Further, by inserting the protrusion of the tip member formed so as to protrude outward into the guide portion formed to be inclined with respect to the axial direction on the side surface of the shaft tube, the tip member is Since it advances while rotating in the axial direction along the guide portion, the moving distance of the tip member becomes longer than the moving distance of the core feeding mechanism that moves straight along the axis, and the tip member returns to the original position. It is possible to delay the time t1 until the time t2 until the lead feeding mechanism returns to the original position.

Furthermore, as the inclination of the guide portion is increased with respect to the axial direction, the moving distance of the tip member becomes longer and the time to return to the original position can be delayed, but the tip member slides smoothly. In order to achieve this, it is necessary to increase the resilience of the first resilient member. Further, when the inclination of the guide portion is small, the moving distance of the tip member is shortened, and the time until the tip member returns to the original position is shortened. For this reason, the inclination of the guide portion is tilted from 10 degrees to 70 degrees with respect to the axial direction so that the tip member moves smoothly with respect to the shaft cylinder and an appropriate time difference is generated in the forward movement of the tip member and the core feeding mechanism. It is preferable.
The guide portion may be linear or curved as long as it is inclined with respect to the axial direction, and may be formed such that the inclination angle changes midway.

In addition, when the protruding portion slides on the guide portion, an appropriate sliding resistance may be generated by rubbing the protruding portion and the guide portion, and the delay speed may be adjusted. In this case, sliding resistance may be generated by adjusting the surface roughness of the contact portion between the protrusion and the guide, and the protrusion and guide are made of an elastic material such as synthetic rubber or silicone rubber. Sliding resistance may be generated by using the film.
Further, as means for adjusting the sliding resistance, a viscous material may be applied to a sliding portion (gap) between the shaft tube and the tip member.
As the viscous material, a grease for a damper can be suitably used, and its consistency (hardness of the grease) is preferably 130 or more and 385 or less, and more preferably 175 or more and 340 or less, so that sliding resistance can be appropriately generated.
In addition, in this invention, the said consistency is a numerical value showing the hardness of grease, and is measured by the method based on JIS-K2220.

  The structure of the lead feeding unit of the present invention is not particularly limited as long as it allows the lead to advance but prevents the lead from retreating. For example, a known ball chuck structure in which a ball is disposed between the chuck and the fastener. Can be suitably used.

  In addition, the shape and configuration of the first elastic member are not limited as long as the front member is elastically forward, but for example, the first elastic member is stretched between the shaft tube and the front member. The tip member may be bulleted forward, or the tip member may be bulleted forward by stretching a first bullet member between the lead feeding mechanism and the tip member.

Further, the shape and configuration of the second elastic member are not limited as long as the first elastic member is elastically projecting the lead feeding mechanism, but for example, between the shaft tube and the core feeding mechanism. The lead feeding mechanism may be repelled forward by stretching it.
Further, it is preferable that the resilience of the second resilient member is higher than the pen pressure so that the lead does not retreat with the pen pressure at the time of writing. For this reason, generally the writing pressure when writing with a writing instrument is about 1.5N to 2.5N, and is about 4.0N at the highest. The force is preferably 4.0 N or more, more preferably 5.0 N or more.

Next, as the second center feeding means, the side slide is formed such that the protruding portion protrudes outward from the side surface of the shaft cylinder, and the protruding portion is moved along the guide portion. An expression may be constructed. In this case, the tip member moves rearward with respect to the shaft tube by gripping the protrusion and sliding within the guide portion of the shaft tube, and when the protrusion is released, the elastic force of the first elastic member is used. The tip member advances. At this time, since the tip member holds the lead by the lead holding member, the lead held by the chuck of the lead feeding mechanism can be pulled forward to feed the lead.
In this second lead feeding means, since the lead is drawn out by sliding the protrusion with a finger while the mechanical pencil is written, there is no need to press the lead against the writing surface, etc. Is not soiled with the core. In addition, the force for gripping the shaft tube during writing is applied to the front side in the axial direction, but in order to feed the lead in the second lead feeding means, it is necessary to move the protrusion to the rear side. Thus, even if a finger hits the protrusion, the protrusion does not move, and there is an effect of preventing the lead from being drawn forward against the user's will.

Moreover, as a 3rd center supply means, the slide member which can be moved back and forth is arranged in the inside of the said tip member, and the automatic centering type which extends a core by repelling a slide member ahead by a 3rd elastic member is used. In this case, when the core wears during writing and the slide member comes into contact with the writing surface and moves backward, the slide member moves away from the writing surface and the slide member moves forward. While the lead holding member holds the lead, the lead held by the chuck of the lead feeding mechanism can be pulled forward and the lead can be fed forward.
In the third lead feeding means, the lead can be fed forward by pressing the lead backward together with the slide member even when the lead is not drawn from the slide member, and the tip of the slide member is the writing surface. If it is allowed to always be in a contact state, writing is continued until the lead feeding unit can no longer hold the lead from the automatic centering type, and the usability is improved.

Furthermore, as the fourth lead feeding means, a knock body protruding rearward from the rear end opening of the shaft tube is provided, and the lead feeding mechanism is operated by pushing the knock body forward, and the lead is moved. A rear end knock-type core feeding structure that feeds forward may be provided.
In the fourth lead feeding means, when the lead is used up by writing, the operation until the next lead in the lead feeding unit protrudes from the tip of the tip member becomes easy.

  As described above, in the present invention, four types of lead feeding means can be provided at the same time, and therefore the lead feeding means can be arbitrarily selected according to various situations during use and user's preference.

  In addition to the four types described above, the lead feeding means is provided with a weight body that can move back and forth in the shaft cylinder, and the lead feeding mechanism is operated by the inertial force of the weight body by shaking the shaft cylinder. Alternatively, a swinging structure for feeding out or a side knock structure for feeding out the core by pressing the operating part may be provided on the side surface of the shaft tube.

  In the present invention, according to the consumption of the lead at the time of writing, the user can obtain a mechanical pencil with a simple structure by which the lead is fed forward by pressing the lead against the writing surface at an arbitrary timing. It was.

It is a side view of the mechanical pencil of a present Example. It is a longitudinal cross-sectional view of the mechanical pencil of a present Example. It is sectional drawing to which the principal part of the present Example was expanded. It is sectional drawing in the AA of FIG. It is the side view to which the operation part of the present Example was expanded. It is a longitudinal cross-sectional view which shows the writing state of the mechanical pencil of a present Example. It is a longitudinal cross-sectional view of the state which applied strong press to the core from the state of FIG. It is a longitudinal cross-sectional view of the state which canceled the press to a core from the state of FIG. It is a longitudinal cross-sectional view of the state where the lead-out operation has been completed from the state of FIG. It is explanatory drawing which shows the operation state of the operation part of a present Example, FIG. 10 (A) is a side view before operating an operation part, FIG.10 (B) moves an operation part along a guide part. It is a side view which shows the state.

Hereinafter, the mechanical pencil of the present embodiment will be described with reference to the drawings, but the present invention is not limited to the following mechanical pencil.
In this embodiment, the side with the writing tip is expressed as the front, and the opposite side is expressed as the rear. Moreover, the side close to the axial center of the shaft cylinder is expressed as inward, and the opposite side is expressed as outward.

1 is a side view of the mechanical pencil of the present embodiment, FIG. 2 is a vertical cross-sectional view of the mechanical pencil 1 of FIG. 1, FIG. 3 is an enlarged vertical cross-sectional view of the main part, and FIG. FIG. 5 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 5 is an enlarged side view of the operation unit.
As shown in FIGS. 1 and 2, the mechanical pencil 1 includes a front shaft member 2 that is formed in a cylindrical shape, a rear shaft member 3 that is screwed into the rear portion of the front shaft member 2, and a front side of the front shaft member 2. A tip member 4 inserted from the opening and a cap 5 attached to the rear portion of the rear shaft member 3 are provided. In addition, a tip opening 4 a into which the slide member 6 can be inserted is formed at the tip of the tip member 4. Further, a tip hole portion 6 a into which the core 7 can be inserted is formed at the tip of the slide member 6.
In this embodiment, the front shaft member 2 and the rear shaft member 3 constitute a shaft cylinder 8.

As shown in FIGS. 2 and 3, a ball chuck 9 having a head 9a divided into two is disposed inside the shaft tube 8, and a hemispherical recess 9b is formed on the outer surface of the head 9a. It is formed. A spherical steel ball 10 is inserted into the recess 9 b of the ball chuck, and a cylindrical fastener 11 is disposed so as to surround the steel ball 10 and the ball chuck 9.
In addition, an inclined portion 11a having a diameter increasing toward the front is formed on the inner surface of the front portion of the fastener 11, and the inclined portion 11a is disposed so that the steel ball 10 inserted into the concave portion 9b of the ball chuck 9 comes into contact therewith. It is.
Further, a step portion 9 c is formed on the outer surface of the ball chuck 9. A chuck spring 12 is stretched between the step portion 9 c and the inner step formed on the inner surface of the fastener 11. It is repelled rearward with respect to the fastener 11.

  A cylindrical connector 13 having an inner hole through which the core 7 can pass is disposed behind the ball chuck 9. When the connector 13 moves forward, the rear end of the ball chuck 9 and the front step portion 13 a of the connector 13 are disposed. Are arranged so as to contact each other.

In addition, a sliding cylinder 14 is disposed at an intermediate portion 13 b of the connector 13, and the sliding cylinder 14 is attached to the connector 13 so as to be movable back and forth. Further, the front end of the sliding cylinder 14 is in contact with the rear end of the fastener 11, and the sliding is achieved by stretching a knock spring 15 between the rear portion 14 b of the sliding cylinder 14 and the rear step portion 13 c of the connector 13. The connector 13 is ejected rearward with respect to the moving cylinder 14.
A cylindrical core tank 16 is press-fitted into the rear part of the connector 13, and an eraser 17 is detachably attached to the rear inner hole of the core tank 16. Further, a cap 5 (knock body) is detachably attached to the rear outer surface of the core tank 16 protruding rearward from the rear inner hole of the rear shaft member 3.

In this embodiment, as described above, a general ball chuck type lead feeding mechanism in which the steel ball 10 is sandwiched between the ball chuck 9 and the fastener 11 is employed. When the lead 7 is retracted, a wedge action is exerted when the lead 7 is retracted, and the lead 7 is strongly held. However, when the lead 7 is advanced, the wedge action is canceled and the lead 7 can be pulled out with a small force.
In this embodiment, the ball chuck 9, the steel ball 10, the fastener 11, the chuck spring 12, the connector 13, the sliding cylinder 14, the knock spring 15, and the core tank 16 constitute a core feeding mechanism 18.

Further, a cylindrical tube body 19 is disposed inside the shaft tube 8 and outside the fastener 11, and a window portion 19 a formed on the side surface of the tube body 19 and an outer surface of the sliding tube 14. The cylindrical body 19 and the sliding cylinder 14 are fixed integrally with each other by engaging the claw portion 14a formed so as to protrude outward from the cylinder.
A front step portion 19b is formed in the front inner hole of the cylindrical body 19, and when the fastener 11 advances, an outer step portion 11b formed on the outer surface of the fastener 11 and a front step portion 19b of the cylindrical body 19 The forward movement of the fastener 11 is restricted by being configured so that the abuts. In addition, a slit portion 19c that penetrates the inside and outside and extends in the axial direction is formed on the side surface of the cylindrical body 19.

As shown in FIGS. 2, 3, and 4, the cylindrical body 19 can be moved back and forth in the rear inner hole 4 c of the tip member 4 inserted from the front end opening 8 a of the shaft tube 8 (front shaft member 2). Inserted. Further, two side holes 4d penetrating the inside and outside are formed on the side surface of the tip member 4 symmetrically with the shaft center in between. The side hole 4d is formed in a nail shape, and a key member 20 having a flange 20a (protrusion) is press-fitted and fixed. The tip of the key member 20 protrudes inward from the inner surface of the tip member 4. The protruding portion 20b is inserted into the slit portion 19c of the cylindrical body 19 so that the cylindrical body 19 can move back and forth with respect to the tip member 4 and cannot rotate.
Further, the key member 20 is press-fitted in a state of protruding outward from the outer surface of the tip member 4, and as shown in FIG. 5, the flange portion 20a is inclined on the side surface of the front shaft member 2 with respect to the axial direction. By arranging in the guide portion 2a formed in this manner, the front member 4 is configured to rotate in the axial circumferential direction while moving the front member 4 back and forth with respect to the front shaft member 2.
As a result, the projecting portion 20b of the key member 20 can move back and forth with respect to the tip member 4 only by the gap between the slit portion 19c and the projecting portion 20b within the slit portion 19c of the cylinder body 19. Is configured to be rotatable while moving back and forth with respect to the front shaft member 2 only by a gap between the flange portion 20a of the key member 20 and the front and rear ends in the guide portion 2a of the front shaft member 2.
In the present embodiment, the guide portion 2a is formed to be inclined by 45 degrees with respect to the axial direction of the front shaft member 2.

Further, the flange portion 20a (projection portion) of the key member 20 is formed so as to protrude outward from the outer peripheral surface of the front shaft member 2, and the flange portion 20a (projection portion) is guided by the front shaft member 2. The inside of the part 2a is configured to function as an operation part 20c that can reciprocate from the outside.
As shown in FIG. 5, the operation portion 20c is formed with a plurality of groove portions 20d extending in a direction orthogonal to the longitudinal direction of the guide portion 2a so that the operation portion 20c does not slip when operated. It is.

The cylindrical body 19 will be described in more detail. The cylindrical body 19 is formed with an inner step portion 19d on the inner surface of the rear portion, and the rear spring 21 (the second spring 21) is interposed between the inner step portion 19d and the front step portion 3a of the rear shaft member 3. The cylindrical body 19 is bulleted forward with respect to the rear shaft member 3 by stretching the bullet member. Since the cylindrical body 19 is connected to the sliding cylinder 14 of the core feeding mechanism 18, the core feeding mechanism 18 is attached to the rear shaft member 3 (shaft cylinder 8) by the rear spring 21 (second elastic member). On the other hand, it is bulleted forward.
In addition, the cylindrical body 19 has an outer step portion 19e formed on the outer surface, and the inner step 2b protruding inwardly on the inner peripheral surface of the front shaft member 2 and the outer step portion 19e abut, The forward movement of the cylinder 19 is limited.

The rear spring 21 (second elastic member) is a spring that supports the writing pressure when writing with the mechanical pencil 1 of the present embodiment. The elasticity is preferably set higher than the writing pressure. In addition, the writing pressure applied to the core during writing is usually about 1.5N to 2.5N, and at most about 4.0N, the elasticity of the rear spring is preferably 4.0N or more, 5.0N or more is more preferable.
Specifically, in this embodiment, the resilience of the rear spring 21 is set to 5.5N.

  The tip member 4 will be described in further detail. An intermediate spring 22 (first elastic member) is stretched between the inner stage 4 b of the tip member 4 and the front end of the tube body 19, so The member 4 is bulleted forward. Since the cylindrical body 19 is connected to the sliding cylinder 14 of the core feeding mechanism 18, the tip member 4 is elastically moved forward with respect to the core feeding mechanism 18 by an intermediate spring 22 (first elastic member). Is done.

In addition, a damper grease is applied as a viscous material to the gap 23 between the tip member 4 and the front shaft member 2, and the damper grease exhibits a damper effect, so that the tip member 4 and the front shaft member 2 A sliding resistance is generated between the two.
In this example, silicone grease (trade name G330, manufactured by Shin-Etsu Chemical Co., Ltd.) having a consistency (grease hardness) of 285 is used as the damper grease.

Further, as described above, the slide member 6 is disposed inside the tip member 4, and the stopper 24 is press-fitted into the intermediate inner hole of the tip member 4 so as to surround the slide member 6 from the rear side of the slide member 6. It is.
In addition, a front spring 25 (third elastic member) is stretched between the intermediate step portion 6 b of the slide member 6 and the outer step portion 24 a of the stopper 24, so that the slide member 6 is attached to the tip member 4. Bulleted forward.

The slide member will be described in more detail. A core holder 26 made of synthetic rubber that holds the core 7 with an appropriate force is built in the inner hole of the slide member 6. As the synthetic rubber constituting the core holder 26, silicon rubber, nitrile rubber, or the like can be used. In this embodiment, the rubber is molded from silicon rubber.
The core holding force of the core holder 26 is set to be stronger than the force of pulling the core forward when the core 7 is held by the ball chuck 9 and weaker than the force of pushing the core rearward.

Next, using FIGS. 2, 3, 6, 7, 8, and 9, writing is performed with the mechanical pencil 1 in the state of FIG. 3, and the core 7 protruding from the distal end hole portion 6 a of the slide member 6 is formed. A description will be given of a first lead feeding means for feeding the lead 7 by pressing the lead 7 strongly backward when worn.
When the mechanical pencil 1 of the present invention grips the shaft cylinder 8 in the state of FIG. 3 and writes with a normal writing pressure, the core 7 protruding from the tip hole portion 6a of the slide member 6 is gradually worn with writing. In the state of FIG. 6, when the shaft 8 is held and the core 7 is strongly pressed against the writing surface 100 and the pressing force exceeds the elastic force of the rear spring 21, the ball chuck 9, the fastener 11, the connector 13, Although the sliding cylinder 14 and the cylinder 19 are stopped, the shaft cylinder 8 gripped by the hand moves forward with respect to the cylinder 19 and the tip member 4, and is in the state of FIG. At this time, the cylinder 19 is springed forward by the compression of the rear spring 21, but the cylinder 19 is connected to the sliding cylinder 14, and the front end of the sliding cylinder 14 contacts the rear end of the fastener. Therefore, the cylinder 19 does not move forward. Further, the tip member 4 is springed forward with respect to the cylinder body 19 by the intermediate spring 22, but the front end of the protruding portion 20 b of the key member 20 crimped to the tip member 4 is the slit portion 19 c of the cylinder body 19. Since it is in contact with the front end of the cylinder 19, it does not move with the cylinder 19. Furthermore, since the slide member 6 in the tip member 4 also holds the lead by the lead holder 26, it does not move and remains stopped.

Here, when the pressure on the core 7 is released and the core 7 is separated from the writing surface 100, the cylindrical body 19 moves forward with respect to the shaft cylinder 8 due to the elastic force of the rear spring 21, and the cylindrical body together with the cylindrical body 19. The entire lead feeding mechanism 18 connected to 19 moves straight forward.
At this time, as the cylindrical body 19 moves forward, the tip member 4 that is springed forward by the intermediate spring 22 with respect to the cylindrical body 19 also tries to move forward, but the flange portion 20a of the key member 20 is Since it moves along the guide part 2a, the tip member 4 connected to the key member 20 advances while rotating along the guide part 2a. Therefore, the tip member 4 that moves forward while rotating is extended in a length that moves forward with respect to the core feeding mechanism 18 that moves forward without rotating, and therefore the time (t1) until the tip member 4 moves forward and returns to the original position. )> The time (t2) is required until the lead feeding mechanism 18 moves forward and returns to the original position.
The tip member 4 has a sliding resistance (damper function) due to the silicon grease applied to the gap 23, so that the time (t2) for the tip member 4 to move forward and return to the original position is further delayed. The lead feeding mechanism 18 is in the state shown in FIG. At this time, the lead feeding mechanism 18 moves forward together with the lead 7 before the leading member 4 moves forward, so that the lead 7 protrudes forward from the tip hole portion 6 a of the slide member 6.

  Further, the tip member 4 that has been delayed in advance moves forward together with the slide member 6 by the elastic force of the intermediate spring 22, but the slide member 6 holds the core 7 by the core holder 26, so that the advancement is finished. The lead 7 is pulled forward from the ball chuck 9 of the lead feeding mechanism 18, and the operation ends in a state where the protrusion amount of the lead 7 from the tip hole portion of the slide member 6 is increased as shown in FIG. 9.

Next, a state in which the lead is drawn forward by operating the operation portion 20c of the key member 20 press-fitted and connected to the tip member 4 as the second lead feeding means will be described.
When the operation portion 20c is moved backward in the guide portion 2a with the finger or the like from the state of FIG. 2 so as to be in the state of FIG. 10 (A) to FIG. 10 (B), the tip connected to the key member 20 The member 4 also moves backward against the elastic force of the intermediate spring 22. At this time, the slide member 6 that is bulleted forward with respect to the tip member 4 is also pushed by the tip member 4 to move backward while holding the core 7, but as described above, the ball chuck 9 moves backward. Since the core 7 is strongly held to the side, the core 7 does not move, and only the slide member 6 moves backward while sliding the core 7, and the core 7 protrudes from the tip hole portion 6a of the slide member 6. The amount is increased.

Here, when the operation portion 20 c is released, the front member 4 moves forward with respect to the front shaft member 2 (shaft cylinder 8) by the elastic force of the intermediate spring 22, and elastically moves forward together with the front member 4 by the front spring 25. The slide member 6 being moved also moves forward.
Since the slide member 6 holds the lead 7 by the lead holder 26, the operation is completed in a state where the lead 7 is pulled forward from the ball chuck 9 and the lead 7 is drawn forward.

Next, as a third lead feeding means, a state in which the lead is drawn forward by the tip of the slide member 6 coming into contact with the writing surface due to wear of the lead during writing will be described.
Since the slide member 6 is springed forward with respect to the tip member 4 by the front spring 25, when the core 7 is worn by writing and the slide member 6 comes into contact with the writing surface, the slide member 6 is moved to the front spring 25 by writing pressure. It moves backward with respect to the tip member 4 against the elastic force.
Here, when writing is stopped and the writing pressure applied to the core 7 is released, the slide member 6 moves forward while the core 7 is held by the core holder 26 by the elastic force of the front spring 25. At this time, since the slide member 6 holds the lead 7 by the lead holder 26, the lead 7 is pulled forward from the ball chuck 9, and the lead 7 is drawn forward, so that the slide member 6 also functions as an automatic centering type mechanical pencil. It is configured.

Next, a state where the lead 7 is drawn forward by pressing the cap 5 forward (knocking operation) as a fourth lead feeding means will be described.
2 will be described. When the cap 5 is pushed forward from the state shown in FIG. 2 (knock operation), the lead tank 16 pushed by the cap 5 moves forward, and the ball chuck is moved accordingly. 9, the core 7 held between the ball chucks 9, the connector 13, the steel balls 10, and the fastener 11 move forward, but the outer step portion 11 b abuts on the front step portion 19 b of the cylindrical body 19, so that the fastener 11 The ball chuck 9 and the lead 7 are moved forward with respect to the fastener 11, and the head 9 a of the ball chuck 9 is further expanded to release the pinching state of the lead 7 and the lead 7 is moved forward. Stops.
When the pressing (knocking operation) of the cap 5 is released, the ball chuck 9, the steel ball 10, the connector 13, and the lead tank 16 are retracted by the resilient force of the chuck spring 12 and the knock spring 15, but the lead 7 is the lead. Since it is held by the holder 26, it does not move backward, each part of the lead feeding mechanism 18 returns to its original position, and only the lead 7 is fed forward, and the mechanical pencil 1 of this embodiment is a conventional one. Also functions as a rear-end knock type mechanical pencil.

As described above, it is possible to obtain a mechanical pencil with a simple configuration in which the lead is fed forward by the user pressing the lead against the writing surface at an arbitrary timing according to the consumption of the lead at the time of writing.
Further, the present invention has four types of lead feeding means including pressing the lead against the writing surface, and the lead feeding means can be arbitrarily selected according to the user's preference and usage situation. It is possible to provide a mechanical pencil with significantly improved.

1 ... mechanical pencil,
2 ... front shaft member, 2a ... guide part, 2b ... inner peripheral projection,
3 ... rear shaft member, 3a ... front part,
4 ... tip member, 4a ... tip opening, 4b ... inner stage, 4c ... rear inner hole, 4d ... side hole,
5 ... Cap,
6 ... slide member, 6a ... tip hole, 6b ... intermediate step 7 ... core,
8 ... Shaft tube, 8a ... Front end opening,
9 ... ball chuck, 9a ... head, 9b ... concave, 9c ... step,
10 ... steel balls,
11 ... Fastener, 11a ... Inclined part, 11b ... Outer step part,
12 ... Chuck spring,
13 ... Connector, 13a ... Front step, 13b ... Intermediate portion, 13c ... Back step,
14 ... sliding cylinder, 14a ... claw part, 14b ... rear part,
15 ... Knock spring,
16 ... Core tank,
17 ... Eraser,
18 ... Core feeding mechanism,
19 ... cylinder, 19a ... window part, 19b ... front part, 19c ... slit part, 19d ... inner part,
19e: outer step,
20 ... key member, 20a ... collar part, 20b ... projecting part, 20c ... operation part, 20d ... groove part,
21 ... Back spring (second elastic member),
22 ... Intermediate spring (first elastic member),
23 ... Gap,
24 ... Stopper, 24a ... Outer step,
25 ... Front spring (third elastic member),
26 ... Core holder,
100 ... Writing surface.

Claims (4)

A shaft cylinder, a core feeding mechanism having a chuck disposed in the shaft cylinder and allowing the advancement of the core but preventing the backward movement, and a core holding member for holding the core with an appropriate force, A mechanical pencil that pushes the lead forward by pressing the lead backward along the axis,
A tip member in which the core holding member is provided in the shaft tube is disposed so as to move back and forth by projecting the front end from the front end opening of the shaft tube,
The shaft cylinder includes a first elastic member that elastically projects the tip member forward, and a second elastic member that elastically projects the core feeding mechanism forward,
On the side surface of the shaft tube, there is a guide portion inclined with respect to the axial direction,
The side surface of the tip member has a protrusion that is inserted into the guide portion of the shaft tube and moves within the guide portion,
By applying a pressing force that pushes the lead backward to the lead, the lead feeding mechanism and the tip member are moved against the elastic force of the first elastic member and the second elastic member. Retreat against the tube,
A time t1 from when the pressing force is released to the time when the tip member moves forward and returns to the original position, and a time from when the pressing force is released to the time when the lead feeding mechanism moves forward and returns to the original position A mechanical pencil characterized in that t2 satisfies a relationship of t1> t2. The protrusion of the tip member is formed so as to protrude outward from the side surface of the shaft tube,
2. The mechanical pencil according to claim 1, wherein the core is drawn forward by gripping the protruding portion and reciprocatingly moving in the guide portion along the guide portion of the shaft tube. A slide member in which the core holding member is provided in the tip member is disposed so as to be movable back and forth by projecting the front end from the tip opening of the tip member,
By stretching a third elastic member between the tip member and the slide member, the slide member is elastically forward,
3. The mechanical pencil according to claim 1, wherein at the time of writing, the slide member is retracted with respect to the tip member to feed the core forward.   A knock body protruding rearward from the rear end opening of the shaft cylinder is provided behind the core feeding mechanism, and the core is fed forward by pushing the knock body forward. The mechanical pencil according to any one of claims 1 to 3.

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