JP6275195B2 - mechanical pencil - Google Patents

Description

  The present invention relates to a mechanical pencil that can sequentially draw out a writing core by using a writing pressure accompanying a writing operation.

  As is well known, mechanical pencils, for example, operate a knocking part protruding from the rear end of the shaft cylinder so that a certain amount of writing core is fed out from the tip member attached to the front end side of the shaft cylinder. To do. That is, since the lead wears with the writing operation, it is necessary to knock the knocking portion every certain writing operation.

In this case, various considerations have been made in the design for the appropriate lead size of the lead fed out by a single knocking operation. However, if the lead feeding amount by a single knocking operation is large, the writing pressure is applied. This causes problems such as frequent breakage of the lead.
Further, if the lead feeding amount by one knocking operation is small, the lead is worn by the writing operation, so that it is necessary to frequently repeat the knocking operation during the writing operation, resulting in a problem that the operation is troublesome.

  Therefore, a pipe-sliding mechanical pencil that moves so that the pipe-shaped core guide attached to the tip member moves forward along with the protruding movement of the writing core accompanying the knocking operation, and the core guide also moves backward when the core is worn due to writing. This has been proposed, and is disclosed in Patent Documents 1 and 2 and the like.

According to the pipe slide type mechanical pencils disclosed in Patent Documents 1 and 2 described above, the tip of the pipe-shaped core guide comes into contact with the paper surface due to wear of the core accompanying writing, so that the core guide gradually retracts. To work.
As a result, even if the protruding amount of the core from the lip portion by one knocking operation is set to be somewhat large, the writing core is protected by the pipe-shaped core guide, and the degree of occurrence of the core breakage accompanying writing can be reduced. it can.

  However, according to the pipe slide type mechanical pencils disclosed in Patent Documents 1 and 2, the tip pipe formed of a metal such as stainless steel rubs the paper surface due to wear of the core accompanying writing. Therefore, the brush resistance is deteriorated due to the frictional resistance at this time, and in an extreme case, the edge portion of the tip pipe is caught on the paper surface, and the paper surface is damaged.

  Therefore, the applicant of the present invention maintains the amount of protrusion of the writing core from the tip pipe within a certain range by operating the tip pipe so as to gradually retract into the tip as the writing wears the core. A mechanical pencil that can be used has been previously proposed, and is disclosed in US Pat.

JP-A-8-072473 JP-A-8-132782 JP 2009-233922 A

  According to the mechanical pencil disclosed in Patent Document 3, the tip pipe that functions as a lead guide operates to gradually retract into the tip using the writing pressure applied to the writing lead as it is written. Therefore, since the tip pipe also moves backward in accordance with the wear of the core accompanying writing, the operation of the tip pipe rubbing the paper surface can be avoided, and at the same time, the above-described problem of the core break can be solved.

By the way, according to the mechanical pencil disclosed in Patent Document 3, it is necessary to knock the above-described knock portion in a state where the core is worn to some extent, although the tip pipe also retracts according to the wear of the core accompanying writing, By this knocking operation, the tip pipe is fed out together with the writing core.
Then, each time the knocking operation is performed, the tip pipe is greatly extended together with the writing core from the lip portion, which may cause a problem that the writing feeling is uncomfortable.

  This invention has been made on the basis of the technical background described above, and is characterized in that it operates so that the writing core is gradually drawn out in response to the wear of the core accompanying the writing operation. A mechanical pencil that can maintain the lead-out dimension of the lead core from the tip pipe almost constant, or one-time knock. It is an object to provide a mechanical pencil that can be written for a long time by operation.

  The mechanical pencil according to the present invention, which has been made to solve the above-described problems, includes a ball chuck that allows the writing core to move forward and prevents retraction, and the writing core gripped by the ball chuck includes It is characterized by comprising a lead feeding mechanism for feeding the writing lead forward in response to an axial retreating operation by the writing pressure received and an axial advance operation by releasing the writing pressure.

  In this case, in a preferred embodiment, the lead feeding mechanism is fed by the axial retraction operation by the writing pressure received by the writing core held by the ball chuck and the axial advance operation by the release of the writing pressure. A feed amount adjustment mechanism for adjusting the lead feed amount is provided.

  Further, the mechanical pencil according to the present invention receives the axial retreat operation by the writing pressure received by the writing core held by the ball chuck and the axial advance operation by the release of the writing pressure, so that the rotor is moved in one direction. It is desirable to further comprise a rotation drive mechanism for rotationally driving, and the core feeding mechanism is configured to receive the rotational driving force of the rotor in the rotational drive mechanism and to feed the writing core forward.

  Further, the above-described core feeding mechanism includes a cam surface that rises in the circumferential direction on an annular end surface, and a cam member that includes a step in the axial direction between the starting point and the final point of the cam surface. And a rotating member that receives the rotational driving force of the rotor in the rotational driving mechanism and that partially contacts the cam surface of the cam member. A slider having a holding chuck that holds the writing core in contact with the slider, and the slider contact member that contacts the cam surface of the cam member falls into the step formed in the axial direction of the slider. It is desirable that the writing core held in sliding contact with the holding chuck is pulled out from the ball chuck by the forward movement.

  The feeding amount adjusting mechanism may adjust the feeding amount of the writing core by adjusting a difference in height of the step.

  In this case, the cam member is a beam-shaped member having either one of the starting point side and the final point side of the cam surface as a fixed end and the other as a free end, and the feed amount adjusting mechanism is an annular end surface And an adjustment cam member provided with an adjustment cam surface that rises in the circumferential direction, and an adjustment contact that is disposed between the cam member and the adjustment cam member and that contacts the adjustment cam surface. Then, when the adjustment cam member is rotated, the free end side of the cam member is moved back and forth by the back-and-forth movement of the adjustment contact caused by sliding the adjustment cam surface according to the rotation. It is desirable that the height difference be adjusted.

  In another preferred embodiment, the cam member is a beam-shaped member having either one of a starting point side or a final point side of the cam surface as a fixed end and the other as a free end, and the feed amount adjusting mechanism includes: An adjustment slider attached to the cam member is provided, and the height difference of the step is adjusted by moving the adjustment slider back and forth to move the free end side of the cam member back and forth.

In still another preferred embodiment, the feed amount adjusting mechanism is configured such that the height difference of the step is adjusted by exchanging the cam member.
In this case, a tip portion is detachably attached to the front end portion of the shaft tube, and the cam member is arranged in the tip portion and is configured to be exchangeable together with the tip portion.

  Further, it is desirable that the writing core is rotationally driven together with the ball chuck that rotates by receiving the rotational driving force of the rotor in the rotational driving mechanism.

  In addition, the ball chuck is configured to move back and forth in the axial direction by a knocking operation of a knock portion arranged in a part of the shaft cylinder, and the gripping action of the writing core by the advancement of the ball chuck, and the ball chuck It is desirable that the writing core can be extended forward by the release action of the writing core due to the backward movement.

  Further, the rotation drive mechanism preferably includes a rotor and first and second cam forming members, and the rotor is formed in an annular shape and has first and second end faces in the axial direction. First and second fixed cam surfaces formed on the first and second cam forming members so as to face the first and second cam surfaces, respectively, with second cam surfaces formed respectively. The first cam surface of the rotor is brought into contact with and meshed with the first fixed cam surface by the retreating operation of the ball chuck by the writing pressure, and the rotor is released by releasing the writing pressure. In which the second cam surface is in contact with and meshed with the second fixed cam surface, and the first cam surface on the rotor side is meshed with the first fixed cam surface. The rotor-side second cam surface; The second fixed cam surface is set in a phase shifted relationship with respect to one tooth of the cam in the axial direction, and the second cam surface on the rotor side is engaged with the second fixed cam surface. In the state, the first cam surface on the rotor side and the first fixed cam surface are set to have a phase shifted with respect to one tooth of the cam in the axial direction.

According to the mechanical pencil having the above-described configuration, the writing core is fed forward in response to an axial retreat operation by the writing pressure received by the writing core held by the ball chuck and an axial advance operation by releasing the writing pressure. It is made like.
Therefore, it works so that the writing core is gradually drawn out in response to the wear of the lead accompanying the writing operation, and the protruding size of the writing core from the tip pipe etc. is made almost constant despite the wear of the lead accompanying the writing. Alternatively, it is possible to provide an ideal mechanical pencil that can be written for a long time with a single knock operation.

The core feeding mechanism is housed in a slider having a cam surface rising along the circumferential direction and a cam member having a step in the axial direction, a contact member contacting the cam surface of the cam member, and the slider. A holding chuck is provided, and the holding core pulls out the writing core from the ball chuck as the slider advances when the slider contacts the cam member.
As a result, the rotational driving force of the rotor in the rotational drive mechanism can be converted into the writing core feeding operation, and the writing core feeding operation with high accuracy and reliable operation can be realized.

Further, the writing core is configured to be rotationally driven together with the ball chuck that rotates in response to the rotational driving force of the rotor in the rotational driving mechanism, so that the writing core is gradually rotated along with the writing operation. Will receive.
Thereby, it is possible to prevent the writing core from being unevenly worn as the writing progresses, and it is possible to solve the problem that the thickness of the drawn line and the darkness of the drawn line change greatly.

  Further, since the lead feeding mechanism has a feeding amount adjusting mechanism for adjusting the feeding amount of the writing lead, the writing lead due to a difference in writing pressure, hardness of the writing lead 4 used, etc. The feeding amount of the writing core 4 can be individually adjusted in accordance with the degree of wear. According to this, it is possible to provide a mechanical pencil that can exhibit the above-described effect of being able to continue writing for a long time with a single knocking operation.

It is sectional drawing which showed the first half part about 1st Embodiment in the mechanical pencil concerning this invention. It is sectional drawing which showed the latter half part similarly. It is the perspective view which fractured | ruptured and showed the front half part in 1st Embodiment. It is the expanded sectional view which showed the structure of the rotational drive mechanism. It is a schematic diagram explaining the rotation drive action of the rotor provided in the rotation drive mechanism step by step. FIG. 6 is a schematic diagram for explaining the rotational driving action of the rotor following FIG. 5. It is the perspective view shown about the core feeding mechanism in 1st Embodiment. It is the perspective view which showed the principal part of the cam member and a slider in the core supply | feeding mechanism shown in FIG. It is sectional drawing which showed the first half part about 2nd Embodiment in the mechanical pencil concerning this invention. It is the schematic diagram which showed the principal part of the cam member and the slider in the core supply | feeding mechanism in 2nd Embodiment. It is sectional drawing which showed the first half part about 3rd Embodiment in the mechanical pencil concerning this invention. It is the perspective view which fractured | ruptured and showed the front half part in 3rd Embodiment. It is the perspective view which showed the principal part of the core feeding mechanism and feeding amount adjustment mechanism which are shown in FIG. It is sectional drawing which showed the first half part about 4th Embodiment in the mechanical pencil concerning this invention. It is sectional drawing of another state which showed the front half part about 4th Embodiment in the mechanical pencil concerning this invention. It is sectional drawing which showed the first half part about 5th Embodiment in the mechanical pencil concerning this invention. It is sectional drawing of another state which showed the front half part about 5th Embodiment in the mechanical pencil concerning this invention. It is the perspective view which fractured | ruptured and showed the front half part in 5th Embodiment. It is sectional drawing which showed the mechanism in which a ball chuck and a writing core do not rotate irrespective of the rotational drive effect | action of a rotor. FIG. 5 is another cross-sectional view showing a mechanism in which the ball chuck and the writing core do not rotate despite the rotational driving action of the rotor. FIG. 21 is a perspective view of the mechanism shown in FIG. 19 and FIG.

  A mechanical pencil according to a first embodiment of the present invention will be described with reference to the drawings. In the drawings shown below, the same parts are denoted by the same reference numerals. However, in some drawings, the representative parts are indicated by reference numerals for the convenience of the page, and the detailed configuration is shown in the other drawings. Each reference will be described with reference to the reference numerals.

In FIG. 1 and FIG. 3 showing the front half of the mechanical pencil, reference numeral 1 denotes a shaft cylinder constituting the outline of the mechanical pencil, that is, a front shaft. It is also called a cutler.) It is detachably attached by screwing 2 in.
The lip portion 2 is configured so that the inner diameter becomes stepped toward the front, and a slider 3 is accommodated therein so as to be slidable in the axial direction and rotatable. . The slider 3 is also configured to have a stepped outer diameter toward the front, and the tip portion 3a of the slider 3 is formed in a columnar shape, and is formed in a cylindrical shape at the front end portion of the lip portion 2. It is accommodated in a state protruding from the formed hole.

  A tip pipe 5 for guiding the writing core 4 is attached to the tip 3 a of the slider 3. In addition, a rubber holding chuck 6 having a through hole formed in the center is accommodated in the internal space of the slider 3 in the immediate vicinity of the tip portion 3 a, and the through hole of the holding chuck 6 serves as the writing core 4. It acts to slidably contact the peripheral surface of the and temporarily hold the writing core.

  An annular cam member 8 is attached in the mouth portion 2 slightly behind the holding chuck 6, and a cam surface of the cam member 8 is formed on the slider 3. The contact 3b is in contact. The relationship between the cam member 8 and the contact 3b formed on the slider 3 will be described in detail later with reference to FIGS.

A ball chuck 9 that holds the writing core 4 is disposed in the internal space of the slider 3. The ball chuck 9 is formed in a cylindrical shape and has a fastener 10 having a tapered surface whose inner peripheral surface expands forward, and the ball chuck 9 is accommodated in the fastener 10, and the writing core 4 extends along the axis. A through hole is formed, and a tip end portion thereof is divided into a plurality of portions along the axial direction, and is disposed between the outer peripheral surface of the chuck main body portion 11 and the inner peripheral surface of the fastener 10. The plurality of balls 12 are provided.
An annular stopper member 13 that prevents the chuck main body portion 11 from moving forward more than a predetermined amount and prevents the ball 12 from falling off is fitted into the inner peripheral surface of the front end portion of the fastener 10. It is.

Therefore, when the writing pressure is applied to the writing core 4, the ball chuck 9 is in contact with the tapered surface of the cylindrical fastener 10 together with the ball 12, so that the writing core 4 is chucked. It is gripped by the main body 11. Thereby, the retraction of the writing core 4 is prevented.
On the other hand, when the force for pulling the writing core 4 forward is applied, the chuck body 11 is not affected by the fastener 10, so that the writing core 4 can be pulled forward with relatively little resistance. That is, the ball chuck 9 acts to allow the writing core 4 to move forward and prevent backward movement.

The chuck body 11 is formed to have a large diameter at the rear end portion with a reduced outer diameter at the central portion in the length direction. A large-diameter portion at the rear end can be slid in the axial direction along the inner peripheral surface of the rear end portion of the slider 3.
A coiled spring 14 is disposed so as to surround the central portion of the chuck body 11 in the length direction, and a front end of the spring 14 is formed on a step formed on the inner peripheral surface of the fastener 10. The rear end of the spring 14 is in contact with the large diameter portion on the rear end side of the chuck body 11.

  Accordingly, the spring 14 acts to urge the chuck body 11 backward by an axially expanding action, whereby the ball chuck 9 is in a state of gripping the writing core 4. Therefore, the spring 14 is referred to as a chuck spring for convenience.

The slider 3 is configured to be slidable in the axial direction with respect to the outer peripheral surface of the fastener 10 constituting the ball chuck 9, and the fastener 10 is formed in a cylindrical shape on the rear end side. The first relay member 16 is fitted and attached to the inner peripheral surface. The first relay member 16 is fitted and attached to the inner peripheral surface of a second relay member 17 formed in a cylindrical shape at a substantially central portion in the length direction.
A short shaft-shaped relay pipe 18 formed of a flexible material, for example, synthetic resin, is connected to the inner peripheral surface of the rear end portion of the second relay member 17. Is connected to a rotation drive mechanism described later.

The second relay member 17 described above has a slightly thick inner diameter on the front end side, and covers the rear end of the slider 3 so that it can slide. A spring 20 is accommodated in a space between the front end portion of the relay member 17 having a slightly thick inner diameter and the first relay member 16 described above.
That is, the spring 20 acts to push the slider 3 forward, and works to bring the contact 3b of the slider 3 into contact with the cam surface of the cam member 8 constituting a core feeding mechanism described later. Although the core feeding mechanism will be described in detail later, the spring 20 is referred to as a cam contact spring for convenience.

  On the other hand, a cylindrical body 22 having a through hole for the writing core 4 is slidably accommodated in the space on the rear end side of the first relay member 16 described above. A core case 23 is fitted and attached to the rear end portion of the cylindrical body 22, and the front end portion of the cylindrical body 22 is attached to the chuck body as the core case 23 moves forward by a knocking operation described later. It abuts on the portion 11 and acts to push the chuck body portion 11 forward. Therefore, for convenience, the cylinder 22 is referred to as a knock operation cylinder.

  In the configuration of the rear half of the mechanical pencil shown in FIG. 2, the rear shaft 25 constituting the shaft cylinder is fitted and attached to the rear end portion of the front shaft 1 described above. An outer shaft 26 integrally formed with a clip portion 26a is attached so as to cover the outer side of the rear shaft 25, and the outer shaft 26 is a retaining ring screwed to the rear end portion of the rear shaft 25. 27 is attached.

A rotation drive mechanism 29 is accommodated in the internal space of the rear shaft 25. The rotation drive mechanism 29 is unitized, and the rear end portion of the short shaft-shaped relay pipe 18 formed of the above-described synthetic resin is connected to the rotation drive mechanism 29.
As shown in FIG. 2, the rotational drive mechanism 29 is pressed rearward by a shaft spring 30 interposed between the rear end portion of the front shaft 1, and the diameter of the rear shaft 25 is reduced. The formed step portion 25 a is pressed against the urging force of the shaft spring 30. Thereby, the rotation drive mechanism 29 is fixed in the rear shaft 25.
The configuration and operation of the rotary drive mechanism 29 will be described in detail later with reference to FIGS.

A knock rod 31 as a knock member is slidably attached to the rear shaft 25 in the rear end portion of the rear shaft 25, and the knock between the rear shaft 25 and the knock rod 31 is knocked. A rod return spring 32 is arranged.
A partition wall 31 a having a writing core replenishing hole is formed slightly closer to the rear end than the center of the knock bar 31. An eraser 33 is detachably attached to the rear end portion of the knock bar 31, and a knock cover 34 covering the eraser 33 is detachably attached to the peripheral surface of the rear end portion of the knock bar 31.
A cylindrical member 35 is attached to the rear end portion of the core case 23. By knocking the knock cover 34, the partition wall portion 31a of the knock bar 31 pushes the cylindrical member 35 forward. Accordingly, the lead case 23 also moves forward.

When the knock cover 34 is knocked in the mechanical pencil configuration described above, the lead case 23 moves forward as described above. As a result, the knock actuating cylinder 22 attached to the front end of the lead case 23 moves forward and pushes the chuck body 11 forward.
Along with this, the writing core 4 held by the chuck main body 11 also moves forward and acts so that the writing core 4 is fed out from the tip pipe 5. When the knocking operation is released, the knocking bar 31 is retracted by the action of the return spring 32 and returns to the state shown in FIG.

At this time, the chuck body 11 is retracted by the action of the chuck spring 14, but the writing core 4 is held by the holding chuck 6 accommodated in the slider 3. The writing core 4 is pulled out without resistance from the chuck body 11 and maintained in a state where it is drawn out from the tip pipe 5. Therefore, each time the knocking operation described above is repeated, the writing core 4 can be fed out by a predetermined amount.
Further, by maintaining the knock cover 34 in the knocked state, the chuck body 11 protrudes from the fastener 10 and the gripping of the core 4 is released. In this state, it is possible to push back the writing core 4 that has been drawn out from the tip pipe 5 with a fingertip or the like.

In the mechanical pencil described above, a rotational drive mechanism 29 is accommodated in the rear shaft 25 as shown in FIG.
The rotation drive mechanism 29 includes a rotor and receives an axial retreat operation by the writing pressure received by the writing core 4 held by the ball chuck 9 and an axial advance operation by releasing the writing pressure. Thus, the rotor is driven to rotate in one direction.

  That is, when the writing core 4 receives a writing pressure, the chuck body 11 shown in FIGS. 1 and 3 is slightly retracted, and the fastener 10 is also retracted via the ball 12. A first relay member 16, a second relay member 17, and a relay pipe 18 are connected to the fastener 10, and a retraction operation and a forward operation (hereinafter referred to as cushioning) of the writing core 4 when receiving writing pressure. Is also transmitted to the rotary drive mechanism 29 described above via each member.

  FIG. 4 is a sectional view showing the entire configuration of the rotation drive mechanism 29. The relay pipe 18 shown in FIG. 4 is coaxially arranged so as to cover the core case 23, and the relay pipe 18 rotates the retraction and forward movement (cushion movement) of the writing core based on the writing movement. It is transmitted to the drive mechanism 29 and acts to transmit the rotational motion of the rotor in the rotational drive mechanism 29 generated by the cushion operation to the ball chuck 9 and the slider 3 through the relay pipe 18.

The rotation drive mechanism 29 includes a rotor 40 formed in a cylindrical shape, and the relay pipe 18 is fitted to the inner peripheral surface of the rotor 40 at the front end portion of the rotation drive mechanism 29. Are combined.
The rotor 40 has a large-diameter portion with a slightly larger diameter near the front end, and a first cam surface 40a is formed on one end surface (rear end surface) of the large-diameter portion. A second cam surface 40b is formed on the other end surface (front end surface).

  On the other hand, a cylindrical first cam forming member (also referred to as an upper cam forming member) 41 is arranged to cover the rear end side of the rotor 40 so that the rotor 40 can be rotated. On the outer periphery of the front end portion of the upper cam forming member 41, a cylindrical second cam forming member (also called a lower cam forming member) 42 is fitted and attached to the upper cam forming member 41. .

  A fixed cam surface (also referred to as a first fixed cam surface) 41a is formed on the front end surface of the upper cam forming member 41 facing the first cam surface 40a of the rotor 40. A fixed cam surface (also referred to as a second fixed cam surface) 42 a is formed on the inner surface of the front end portion of the lower cam forming member 42 facing the second cam surface 40 b of the rotor 40.

  Regarding the relationship between the first and second cam surfaces 40a, 40b formed on the rotor 40, the first fixed cam surface 41a, the second fixed cam surface 42a and their interaction, This will be described in detail later with reference to FIGS.

  As shown in FIG. 4, a cylinder member 44 is fitted on the rear end side of the upper cam forming member 41 described above, and an insertion hole 44a through which the core case 23 can be inserted into the rear end portion of the cylinder member 44. Is formed. A torque canceller 45 formed in a cylindrical shape and movable in the axial direction is disposed in the cylinder member 44, and a front end of the inner peripheral surface of the torque canceller 45 and a rear end of the inner peripheral surface of the cylinder member 44 are arranged. A coiled cushion spring 46 is mounted between them.

The cushion spring 46 acts to urge the torque canceller 45 forward, and is pushed by the torque canceller 45 receiving the urging force so that the rotor 40 acts forward.
The rotation drive mechanism 29 is formed in a space through which the core case 23 passes and is isolated from the core case 23. The rotation drive mechanism 29 is united by the members indicated by the reference numerals 40 to 46 as a unit. Has been.

  According to the configuration of the rotation drive mechanism 29 described above, the rotor 40 is connected to the ball chuck via the relay pipe 18, the second relay member 17, and the first relay member 16 while the ball chuck 9 holds the writing core 4. 9. Along with the slider 3, it is rotatable about the axis. When the mechanical pencil is in a state other than the writing state, the rotor 40 is biased forward via the torque canceller 45 by the action of the cushion spring 46.

  On the other hand, when writing is performed with a mechanical pencil, that is, when writing pressure is applied to the writing core 4 protruding from the tip pipe 5, the ball chuck 9 is slightly retracted against the urging force of the cushion spring 46. As a result, the rotor 40 also moves backward in the axial direction. Therefore, the first cam surface 40a formed on the rotor 40 shown in FIG. 4 is joined and engaged with the first fixed cam surface 41a.

5 (A) to 5 (C) and FIGS. 6 (D) and 6 (E) explain the basic operation of the rotation driving mechanism 29 for rotating the rotor 40 by the above-described operation in order.
5 and 6, reference numeral 40 schematically shows the above-described rotor, and one end surface (the upper surface in the drawing) is continuously serrated along the circumferential direction. The first cam surface 40a is formed in an annular shape. Similarly, a second cam surface 40b that is continuously serrated along the circumferential direction is formed in an annular shape on the other end surface (the lower surface in the drawing) of the rotor 40.

  On the other hand, as shown in FIGS. 5 and 6, the first fixed cam surface 41 a that is continuously serrated along the circumferential direction is also formed on the annular end surface of the upper cam forming member 41, A second fixed cam surface 42 a that is continuously serrated along the circumferential direction is also formed on the annular end surface of the lower cam forming member 42.

  Then, the first cam surface 40a formed on the rotor 40, the second cam surface 40b, the first fixed cam surface 41a formed on the upper cam forming member 41, and the first cam surface formed on the lower cam forming member 42. The cam surfaces formed in a sawtooth shape along the circumferential direction of the two fixed cam surfaces 42a are formed so that their pitches are substantially the same. In FIG. 5 and FIG. 6, the circles drawn at the center of the rotor 40 indicate the rotational movement state of the rotor 40.

FIG. 5A shows the relationship among the upper cam forming member 41, the rotor 40, and the lower cam forming member 42 when the mechanical pencil is not in the writing state. In this state, the second cam surface 40b formed on the rotor 40 abuts against the second fixed cam surface 42a side of the lower cam forming member 42 by the urging force of the cushion spring 46 shown in FIG. Has been.
At this time, the first cam surface 40a on the rotor 40 side and the first fixed cam surface 41a are set so as to have a half-phase (half-pitch) offset from one cam tooth in the axial direction. ing.

  FIG. 5B shows an initial state in which the writing pressure is applied to the writing core 4 by using the mechanical pencil. In this case, the rotor 40 retracts in the axial direction by contracting the cushion spring 46 via the ball chuck 9 and the relay pipe 18. Thereby, the rotor 40 moves to the upper cam forming member 41 side.

FIG. 5C shows a state in which writing pressure is applied to the writing core 4 by using a mechanical pencil, and the rotor 40 is in contact with the upper cam forming member 41 side. In this case, the rotor 40 is formed on the rotor 40. The first cam surface 40a thus engaged meshes with the first fixed cam surface 41a on the upper cam forming member 41 side. Thereby, the rotor 40 receives a rotational drive corresponding to a half phase (half pitch) of one tooth of the first cam surface 40a.
In the state shown in FIG. 5C, the second cam surface 40b on the rotor 40 side and the second fixed cam surface 42a are half phase (half pitch) with respect to one tooth of the cam in the axial direction. It is set to be in a shifted relationship.

  Next, FIG. 6D shows an initial state in which the writing with the mechanical pencil is finished and the writing pressure on the writing core 4 is released. In this case, the rotor 40 is operated by the action of the cushion spring 46 described above. Moves forward in the axial direction. Thereby, the rotor 40 moves to the lower cam forming member 42 side.

  Further, FIG. 6E shows a state in which the rotor 40 is in contact with the lower cam forming member 42 side by the action of the cushion spring 46 described above, and in this case, the second formed on the rotor 40 is shown. The cam surface 40b meshes with the second fixed cam surface 42a on the lower cam forming member 42 side. As a result, the rotor 40 again receives a rotational drive corresponding to a half phase (half pitch) of one tooth of the second cam surface 40b.

Therefore, as indicated by the circles drawn at the center of the rotor 40, the rotor 40 receives the first and second cam surfaces 40a, A rotational drive corresponding to one tooth (one pitch) of 40b is received.
Thereby, the writing core 4 held by the ball chuck 9 via the relay pipe 18, the second relay member 17, and the first relay member 16 is also rotationally driven together with the slider 3.

  In the rotation drive mechanism 29 shown in FIG. 4, the cylindrical torque canceller 45 that pushes the rotor 40 forward by receiving the urging force of the coil-shaped cushion spring 46 has the front end surface of the torque canceller 45 and the rotation. A slip is generated between the rear end surface of the child 40 and the rotational movement of the rotor 40 is prevented from being transmitted to the cushion spring 46.

  In other words, since the torque canceller 45 is interposed between the rotor 40 and the cushion spring 46, the rotational motion of the rotor 40 is transmitted to the cushion spring 46 by the sliding action described above. Acts to prevent. As a result, it is possible to solve the problem that the spring 46 is twisted back (spring torque) and the rotation operation of the rotor 40 is obstructed.

Next, FIG. 7 and FIG. 8 explain the configuration of the core feeding mechanism. The lead feeding mechanism receives the rotational driving force of the rotor 40 in the rotational driving mechanism 29 and acts to feed the writing lead 4 forward.
7 is a perspective view showing the front half of the mechanical pencil in a state in which the front end portion is removed in a state where a part thereof is broken, and FIG. It is the perspective view which showed the relationship with a slider.

A cam member 8 formed in an annular shape so as to surround a columnar tip portion 3 a formed on the slider 3 is arranged in a state of being accommodated in the above-mentioned mouth end portion 2.
As shown in FIG. 8, the cam member 8 includes a cam surface 8a that rises in the circumferential direction on an annular end surface, and also has a starting point (low position) and a final point (high position) of the cam surface 8a. The position 8b is provided with a step 8b in the axial direction.
That is, the axial step 8b connects the starting point and the final point of the cam surface 8a.

  On the other hand, an abutment 3b protruding in the axial direction is formed integrally with the slider 3 at the base of the tip 3a formed in a columnar shape in the slider 3, and the action of the cam abutting spring 20 is achieved. The contact 3 b is in contact with the cam surface 8 a of the cam member 8 by receiving the forward movement of the slider 3.

In the configuration described above, the rotor 40 of the rotation drive mechanism 29 gradually drives the slider 3 to rotate based on the cushioning action of the writing core. That is, in this embodiment, when the tip 3a of the slider 3 is viewed first, the slider 3 is rotated clockwise.
Thereby, the contact 3b formed on the slider 3 operates so as to rise along the cam surface 8a of the cam member 8, and the slider 3 gradually retracts in the axial direction. At this time, the writing core 4 held by the ball chuck 9 acts so as to be relatively fed out from the tip pipe 5.

When the contact 3b of the slider 3 reaches the axial step 8b formed on the cam member 8, the contact 3b falls along the step 8b by the action of the cam contact spring 20. At that moment, the slider 3 also receives a forward movement corresponding to the height difference of the step 8b.
At this time, the holding chuck 6 accommodated in the slider 3 advances in the same manner, so that the writing core 4 held in sliding contact with the holding chuck 6 is operated to be pulled out from the ball chuck 9.

  By repeating the above operation, the lead feeding mechanism that receives the rotational force from the rotation drive mechanism 29 acts to gradually feed the writing lead from the tip pipe 5 in response to wear of the writing lead 4 accompanying the writing operation. To do. As a result, it is possible to maintain the writing core protruding dimension from the tip pipe substantially constant despite the core wear caused by writing, and to provide a mechanical pencil that is close to ideal without reducing the efficiency of writing. it can.

  In this case, if the degree of wear of the lead 4 due to writing and the amount of feeding of the writing lead 4 by the above-described lead feeding mechanism are set to substantially coincide with each other, the writing lead from the tip pipe 5 will be used regardless of the writing operation. It is possible to expect an ideal operation that can always keep the output dimension of the substrate constant. However, if the setting of the lead feed amount is slightly shifted and the lead feed amount of the lead 4 is increased with respect to the wear amount of the writing lead 4, the lead 4 protrudes with the writing operation and causes a problem that the lead breaks. .

  Therefore, it is desirable that the amount of feeding of the core 4 is set to be slightly smaller than the amount of wear of the core 4 due to writing. By setting the amount of feeding of the core in this way, the above-described knock cover 34 can be set once. A mechanical pencil that can be written for a long time can be provided by the knocking operation.

  In this embodiment, the writing core 4 held by the ball chuck 9 is also rotated by receiving the rotational driving force of the rotor 40 in the rotational driving mechanism 29. It is possible to prevent the writing core 4 from being unevenly worn as it progresses, and to solve the problem that the thickness of the drawn line and the darkness of the drawn line change greatly.

By the way, in the embodiment shown in the drawing, the cam member 8 that constitutes the above-described core feeding mechanism is accommodated in a tip portion (cuticle) 2 that is detachably attached to the shaft cylinder (tip shaft) 1. In addition, the cutlery 2 and the cam member 8 are configured as separate parts. However, the cam member 8 can be formed as a single part integrally with the cutlery 2.
Thus, even if the former configuration in which the cam member 8 is accommodated in the cutlery 2 or the latter configuration in which the cutlery 2 and the cam member 8 are integrally formed is adopted, the axial direction formed in the cam member 8 By preparing a plurality of types of the step 8b, the user can select a cam member 8 having a different step 8b along with the replacement of the cutlery 2 to adjust the amount of writing lead in the lead feeding mechanism. Is possible.

  If this configuration is used, the writing core 4 can be exchanged by changing the cutting plastic 2 according to the degree of wear of the writing core due to the difference in writing pressure and the hardness of the writing core 4 to be used. The amount of feed can be adjusted individually. According to this, it is possible to provide a mechanical pencil that can exhibit the above-described effect of being able to continue writing for a long time with a single knocking operation.

  Next, FIG. 9 and FIG. 10 show a second embodiment of the mechanical pencil according to the present invention. FIG. 9 is a cross-sectional view showing the structure of the first half, and the parts corresponding to the respective parts in the first embodiment shown in FIGS. Description is omitted.

  In the second embodiment shown in FIG. 9, a spring 50 is disposed between the slider 3 and the ball chuck 9. The spring 50 pushes the slider 3 toward the front in the axial direction and urges the chuck body 11 constituting the ball chuck 9 toward the rear in the axial direction so that the writing core 4 is moved by the ball chuck 9. It also functions as a gripper. That is, the spring 50 performs the operation of the cam contact spring 20 and the chuck spring 14 in the first embodiment shown in FIG. 1 and FIG. For convenience, 50 is referred to as a combined spring.

In the second embodiment, the tip pipe 5 is supported by a pipe support member 51, and is constituted by a member different from the slider 3 in which the holding chuck 6 is accommodated in the shaft core portion.
Further, as shown in the schematic diagram of FIG. 10, the slider 3 is formed with a rod-shaped contact 3b protruding in the axial direction with respect to the main body of the slider 3, and this rod-shaped contact 3b. The front end of the cam member 8 is configured to come into contact with the cam surface 8a of the cam member 8 disposed in the tip 2 by the action of the dual purpose spring 50.

In addition, the cam member 8 in the second embodiment includes a cam surface 8a that rises in the circumferential direction on an annular end surface, and also has a starting point (low position) and a final point (high position) of the cam surface 8a. Between the two positions in the axial direction as indicated by reference numerals 8c and 8d.
That is, in the second embodiment, the rotation driving mechanism 29 is operated by the cushioning operation of the writing core 4 accompanying writing, and the rod-shaped contact 3b formed on the slider 3 thereby has a step difference. By sequentially dropping into 8c and 8d, the contact 3b operates so as to move from the final point (high position) of the cam surface 8a to the starting point (low position).

As shown in FIG. 5C, this is because the first cam surface 40a of the rotor in the rotary drive mechanism is engaged with the fixed cam surface 41a on the upper cam forming member 41 side, and the contact 3b of the slider 3 is engaged. Operates under the step 8c under the action of the dual purpose spring 50.
Subsequently, as shown in FIG. 6E, the contact 3b of the slider 3 is moved to the dual-purpose spring 50 in a state where the second cam surface 40b of the rotor is engaged with the fixed cam surface 42a on the lower cam forming member 42 side. Under the action of the above, it operates so as to fall along the step 8d.

The holding chuck 6 disposed on the slider 3 operates so as to pull out the writing core 4 from the ball chuck 9 when the contact 3b of the slider 3 falls down the steps 8c and 8d. This is the same as the first embodiment.
Therefore, also in the second embodiment shown in FIG. 9 and FIG. 10, it is possible to obtain the same operational effects as those of the first embodiment already described.

The cam member 8 constituting the core feeding mechanism described above forms the step 8b or the two-step steps 8c and 8d at the point where the cam surface 8a formed on the annular end surface makes one round. It can also be formed at a half-circumferential point on the end face of the plate or at a point shorter than that.
This can be set as appropriate in consideration of the number of teeth of the serrated cam constituting the rotary drive mechanism 29, that is, the rotational step amount of the serrated cam.

  Next, FIG. 11 thru | or FIG. 13 shows 3rd Embodiment in the mechanical pencil concerning this invention. FIG. 11 is a sectional view showing the structure of the first half part, FIG. 12 is a perspective view showing the front half partly broken, and FIG. 13 is the core feeding mechanism and feeding amount shown in FIG. FIG. 6 is a perspective view showing a main part of an adjustment mechanism 60. Parts corresponding to the respective parts in the first embodiment shown in FIGS. 1 and 3 are denoted by the same reference numerals, and therefore detailed description thereof is omitted.

  In the third embodiment, the mechanical pencil is used in combination with the lead feeding mechanism described above in the first and second embodiments, and adjusts the feeding amount of the writing lead by the lead feeding mechanism. A feed amount adjusting mechanism 60 is provided. The feed amount adjusting mechanism 60 is similar to the lip portion 2 in the first embodiment and the second embodiment, but has an adjustment lip portion 61 having a different shape, and an adjustment cap 62 that covers the adjustment lip portion 61. It has.

  The adjustment tip 61 will be described in terms of differences from the tip 2 in the first and second embodiments. The adjustment port tip 61 is formed with a slide hole 61a extending in the axial direction at a step portion between a cylindrical portion at the tip and a cylindrical portion formed at a larger diameter following the rear portion. Further, the adjustment mouth end portion 61 includes an engagement protrusion 61b formed in an annular shape on the outer peripheral surface of the cylindrical portion formed to have a large diameter. The engaging protrusions 61b do not have to be formed over the entire outer peripheral surface, and may be a single protrusion or a plurality of protrusions provided at equal intervals in the circumferential direction.

  The adjustment cap 62 has a hole formed in the front end surface thereof, and a cylindrical portion at the tip of the adjustment mouth end 61 projects from the hole. The adjustment cap 62 includes a cylindrical portion formed with a small diameter and a cylindrical portion formed with a large diameter. On the inner peripheral surface of the large-diameter cylindrical portion, an engagement groove 62a provided in an annular shape in a shape complementary to the engagement protrusion 61b of the adjustment port tip 61 is provided.

  In the state where the adjustment cap 62 is put on the adjustment port tip 61, between the hole on the front end surface of the adjustment cap 62 and the cylindrical portion at the tip of the adjustment port tip 61, and within the large-diameter cylindrical portion of the adjustment cap 62. There is a loose fit between the peripheral surface and the outer peripheral surface of the corresponding adjustment tip 61. Further, the rear end surface of the adjustment cap 62 is in light contact with another step portion of the adjustment mouth end portion 61. Therefore, the adjustment cap 62 can rotate around the axial direction with respect to the adjustment mouth end portion 61. The movement of the adjustment cap 62 in the axial direction is restricted by the engagement between the engagement protrusion 61 b of the adjustment port tip 61 and the engagement groove 62 a of the adjustment cap 62.

  Inside the front end of the adjustment cap 62, an adjustment cam member 63 formed in an annular shape so as to surround the cylindrical portion at the tip of the adjustment port tip 61 is provided. An adjustment contact 66 described later is in contact with an adjustment cam surface 63a that is a cam surface of the adjustment cam member 63. The adjustment cam member 63 has a shape similar to that of the cam member 8 in the first embodiment and the second embodiment. That is, the adjustment cam surface 63a is configured to rise along the circumferential direction on the annular end surface, and includes a starting point (low position) and a final point (high position).

  A cam base member 64 formed in an annular shape so as to surround a columnar tip portion 3 a formed in the slider 3 is provided inside the front end of the adjustment port end portion 61. In addition, a cam member 65 formed in an annular shape is provided behind the cam base member 64 so as to surround a cylindrical tip portion 3a formed in the slider 3.

  The cam member 65 includes a cam surface 65a, and the starting point and the final point of the cam surface 65a are separated from each other. However, the cam member 65 is not separated so as to inhibit the circumferential movement of the contact 3b of the slider 3. . The cam member 65 is fixed to the cam base member 64 via the connecting portion 65b at the starting point or the final point of the cam surface 65a or in the vicinity thereof. Therefore, the starting point side or the final point side of the cam surface 65a of the cam member 65 fixed to the cam base member 64 is a fixed end, and the other side is a free end. The cam member 65 is a beam-like member. is there. In this embodiment, the cam member 65 is fixed to the cam base member 64 via the connecting portion 65b at the starting point of the cam surface 65a. The cam member 65 is formed of a flexible material.

  The adjustment abutment 66 is an elongated member, and passes through a hole or notch provided in the slide hole 61a of the adjustment port tip 61 and the corresponding cam base member 64, and the adjustment cam member 63 and the cam member 65. The two ends are in contact with each other. That is, one end of the adjustment contact 66 abuts on the adjustment cam surface 63a of the adjustment cam member 63, and the other end is a surface opposite to the cam surface 65a of the cam member 65 and spaced from the fixed end. Abut. The length of the adjustment contact 66 is such that when the adjustment contact 66 is in contact with the starting point of the adjustment cam member 63, the starting point of the cam surface 65a of the cam member 65 as shown in FIG. And the final point are determined to have the same height, that is, the entire cam surface 65a is on the same plane.

  When the feed amount adjusting mechanism 60 is applied to the first embodiment, the cam contact spring 20 is applied. When the feed amount adjusting mechanism 60 is applied to the second embodiment, the combined spring 50 is used. 3b contacts the cam surface 65a of the cam member 65 and urges the cam member 65 forward. Therefore, the cam member 65 is in contact with the adjustment contact 66 by the biasing force or the restoring force of the flexible cam member 65 itself.

  Next, a method for adjusting the feeding amount of the writing core by the feeding amount adjusting mechanism 60 will be described. As described above, when the adjusting contact 66 is in contact with the starting point of the adjusting cam member 63, the starting point and the final point of the cam surface 65a of the cam member 65 are at the same height. Therefore, the contact 3b only circulates on the same plane along the cam surface 65a. Therefore, the slider 3 does not move back in the axial direction based on the cushioning action of the writing lead by the writing action, and therefore the feeding amount of the writing lead 4 is zero.

  In this embodiment, for example, referring to FIG. 13, when the adjustment cap 62 is gripped and the left end of the slider 3 is viewed first and the counter contact 66 is rotated counterclockwise, the adjustment contact 66 is adjusted by the adjustment cam member. 63, the adjustment abutment 66 gradually retreats in the axial direction along with the adjustment cam surface 63a. At this time, the cam member 65 that is in contact with the other end of the adjusting contact 66 is deformed so that the free end side is retracted so as to be pushed up from below with the fixed end by the connecting portion 65b as a fulcrum. As a result, the cam member 65 forms a cam surface 65a that rises like the cam surface 8a in the first and second embodiments.

  On the other hand, when gripping the adjustment cap 62 and rotating the slider 3 toward the tip 3a first and rotating it clockwise, the adjustment contact 66 is biased by the cam contact spring 20 or the combined spring 50. The cam member 65 operates so as to descend along the adjustment cam surface 63a of the adjustment cam member 63 through the cam member 65 or by the restoring force due to the elasticity of the cam member 65 itself. As a result, the adjustment contact 66 gradually advances in the axial direction. At this time, the free end side of the cam member 65 moves forward with the fixed end by the connecting portion 65b as a fulcrum by the action of the cam contact spring 20 or the combined spring 50 or by the restoring force due to the elasticity of the cam member 65 itself. . When the adjustment cap 62 continues to rotate clockwise and the adjustment contact 66 reaches the starting point of the adjustment cam member 63, the entire cam surface 65a is on the same plane as shown in FIG.

  In summary, when the adjustment cam member 63 is rotated by rotating the adjustment cap 62, the adjustment contact 66 that slides on the adjustment cam surface 63a is moved back and forth in accordance with the rotation. The free end side of the cam member 65 is moved back and forth by the back and forth movement of the adjustment contact 66, and the difference in level of the step between the starting point and the final point of the cam surface 65a is adjusted.

  When the cam surface 65 a is formed so that the cam member 65 rises, the writing core is retracted in the axial direction based on the cushioning action of the writing core by the writing operation and is held by the ball chuck 9. 4 acts so as to be relatively fed out from the tip pipe 5. The relative feeding amount of the writing core 4 at this time is determined by the degree of inclination of the cam surface 65 a, that is, the axial position of the adjusting contact 66 according to the rotation of the adjusting cap 62.

  When the contact 3b of the slider 3 reaches the final point of the cam surface 65a, the contact 3b falls along the step between the start point and the cam contact spring 20 or the combined spring 50. At that moment, the slider 3 also receives a forward movement corresponding to the level difference of the step. At this time, the holding chuck 6 accommodated in the slider 3 advances in the same manner, so that the writing core 4 held in sliding contact with the holding chuck 6 is operated to be pulled out from the ball chuck 9. The feeding amount of the writing core 4 at this time is determined by the height difference of the step, that is, the degree of inclination of the cam surface 65a, in other words, the axial position of the adjusting contact 66 according to the rotation of the adjusting cap 62. Is done.

  Therefore, by adjusting the rotation position of the adjustment cap 62, it is possible to adjust the feeding amount of the writing core 4 in the core feeding mechanism. If this configuration is used, the feeding amount of the writing core 4 can be individually adjusted according to the degree of wear of the writing core due to differences in the writing pressure and the hardness of the writing core 4 to be used. can do. According to this, it is possible to provide a mechanical pencil that can exhibit the above-described effect of being able to continue writing for a long time with a single knocking operation.

  Furthermore, according to the feed amount adjusting mechanism 60 according to the third embodiment, an easy method of rotating the adjustment cap 62 without requiring the replacement work of the cam member 8 as described above in the first embodiment. Thus, it is possible to adjust the feeding amount of the writing core 4. The maximum feed amount that can be adjusted of the writing core 4 by the feed amount adjusting mechanism 60 is determined by the difference in level between the starting point and the final point of the adjusting cam surface 63 a of the adjusting cam member 63. Therefore, the adjustment cam member 63 is configured so as to have the step having a length (height) that exceeds the normally assumed degree of wear of the writing core 4, thereby writing according to the preference of all users. The feeding amount of the lead 4 can be set. As a matter of course, a user who does not like the automatic feeding of the writing core 4 rotates the adjustment cap 62 so that the adjustment contact 66 contacts the starting point of the adjustment cam member 63. What is necessary is just to make it let the feeding amount of the writing core 4 become zero. Note that a scale or the like indicating the relative rotational position may be provided on the outer peripheral surface of the adjustment cap 62 so that the user can visually recognize the current amount of feeding.

  The adjustment cam member 63 is housed in the adjustment cap 62 in the embodiment shown in the figure, and is configured as a separate component from the adjustment cap 62. However, the adjustment cam member 63 can be integrally formed with the adjustment cap 62 as a single component. Similarly, the adjustment port portion 61 and the cam base member 64 may be integrally formed as one part, and the cam base member 64 and the cam member 65 may be integrally formed as one part. The contactor 66 may be integrally formed into one part. Moreover, the adjustment cam surface 63a of the adjustment cam member 63 does not need to form an annular surface extending over the entire circumference, and may be a partial one.

  14 and 15 show a fourth embodiment of the mechanical pencil according to the present invention. FIG. 14 is a sectional view showing the configuration of the first half, and FIG. 15 is a sectional view showing the configuration of the first half. Parts corresponding to the respective parts in the first embodiment shown in FIGS. 1 and 3 and the third embodiment shown in FIGS. 11 to 13 are denoted by the same reference numerals, and detailed description thereof is omitted. To do.

  In the fourth embodiment, the mechanical pencil is used in combination with the lead feeding mechanism described above in the first and second embodiments, and adjusts the feeding amount of the writing lead by the lead feeding mechanism. A feed amount adjusting mechanism 70 is provided. The feed amount adjustment mechanism 70 includes an adjustment port tip portion 71 that is similar to the feed amount adjustment mechanism 60 according to the third embodiment but has a different shape, and an adjustment cap 72 that covers the adjustment port tip portion 71.

  The feed amount adjustment mechanism 70 according to the fourth embodiment does not have the adjustment cam member 63. Instead, the feed amount adjusting mechanism 70 is configured to adjust the difference in level of the step between the starting point and the final point of the cam surface 65a of the cam member 65 by sliding the adjusting cap 72 in the axial direction. This is different from the feed amount adjustment mechanism 60 according to the third embodiment. Therefore, the adjustment cap 72 is referred to as an adjustment slider 72 for convenience.

  Similar to the adjustment port tip portion 61 in the third embodiment, the adjustment port tip portion 71 is formed with a slide hole 71a through which the adjustment contact 66 slides. In addition, the adjustment port tip 71 includes an engagement protrusion 71b formed in an annular shape on the outer peripheral surface of a cylindrical portion formed to have a large diameter, like the adjustment port tip 61 in the third embodiment. Further, a locking projection 71 c is provided at the cylindrical portion at the tip of the adjustment port tip 61. Further, the adjustment port end portion 71 includes an annular wall portion 71 d formed in an annular shape in order to support the outer peripheral surface of the adjustment slider 72. Note that the engaging protrusion 71b and the locking protrusion 71c do not need to be formed over the entire circumference of the outer peripheral surface, and may be one or a plurality of protrusions provided at equal intervals in the circumferential direction.

  The adjustment slider 72 has a hole formed in the front end surface thereof, and a cylindrical portion at the tip of the adjustment mouth end 71 projects from the hole. The adjustment slider 72 includes a cylindrical portion formed with a small diameter and a cylindrical portion formed with a large diameter. On the inner peripheral surface of the large-diameter cylindrical portion, a plurality of engagement grooves 72a provided in an annular shape in a shape complementary to the engagement protrusions 61b of the adjustment port tip 61 are provided.

  In the state where the adjustment slider 72 is put on the adjustment port tip 71, between the hole on the front end surface of the adjustment slider 72 and the cylindrical portion at the tip of the adjustment port tip 71 and within the large diameter cylindrical portion of the adjustment slider 72. There is a loose fit between the peripheral surface and the outer peripheral surface of the corresponding adjustment tip 71. Therefore, the adjustment slider 72 can slide in the axial direction with respect to the adjustment tip 71. The relative position in the axial direction of the adjustment slider 72 with respect to the adjustment port tip 71 can be adjusted stepwise by the engagement between the engagement protrusion 71 b of the adjustment port tip 71 and the plurality of engagement grooves 72 a of the adjustment slider 72. . The maximum advance position of the adjustment slider 72 with respect to the adjustment port tip 71 is determined by the engagement between the edge of the hole on the front end surface of the adjustment port tip 71 and the engagement protrusion 71 c of the adjustment slider 72. Further, the maximum retracted position is determined by the contact between the rear end surface of the adjustment slider 72 and another step portion of the adjustment mouth end portion 71.

  Accordingly, the maximum feed amount that can be adjusted of the writing core 4 by the feed amount adjustment mechanism 70 is determined by the distance between the maximum forward position and the maximum reverse position of the adjustment slider 72 with respect to the adjustment tip 71. Note that the relative position can be adjusted steplessly by increasing the degree of fitting between the adjustment port tip 71 and the adjustment slider 72 without using the engagement protrusion 71b and the plurality of engagement grooves 72a. Good. As a result, the feed amount can be adjusted more finely.

  The adjustment abutment 66 passes through a hole or a notch provided in the slide hole 71a of the adjustment tip 71 and the corresponding cam base member 64, and both ends abut against the adjustment slider 72 and the cam member 65. Is in a state. That is, one end of the adjustment contact 66 abuts against the inner wall of the front end portion of the adjustment slider 72, and the other end abuts against a portion of the cam member 65 opposite to the cam surface 65a and spaced from the fixed end. . The length of the adjustment contact 66 is such that when the adjustment slider 72 is at the maximum forward position, the starting point and the final point of the cam surface 65a of the cam member 65 are at the same height as shown in FIG. That is, it is determined so that the entire cam surface 65a is on the same plane.

  Next, a method for adjusting the feeding amount of the writing core by the feeding amount adjusting mechanism 70 will be described. As described above, when the adjustment slider 72 is at the maximum advanced position, the starting point and the final point of the cam surface 65a of the cam member 65 are at the same height. It only circulates on the same plane along. Therefore, the slider 3 does not move back in the axial direction based on the cushioning action of the writing lead by the writing action, and therefore the feeding amount of the writing lead 4 is zero.

  In this embodiment, when the adjustment slider 72 is pushed in while being gripped and is retracted in the axial direction, the adjustment contact 66 is also retracted in the axial direction. At this time, the cam member 65 that is in contact with the other end of the adjusting contact 66 is deformed so that the free end side is retracted so as to be pushed up from below with the fixed end by the connecting portion 65b as a fulcrum. As a result, the cam member 65 forms a cam surface 65a that rises like the cam surface 8a in the first and second embodiments.

  On the other hand, when the adjustment slider 72 is pulled while being gripped by the adjustment slider 72, the adjustment contact 66 is moved via the cam member 65 biased by the cam contact spring 20 or the combined spring 50. Or it advances to an axial direction with the restoring force by the elasticity of cam member 65 itself. At this time, the free end side of the cam member 65 moves forward with the fixed end by the connecting portion 65b as a fulcrum by the action of the cam contact spring 20 or the combined spring 50 or by the restoring force due to the elasticity of the cam member 65 itself. . When the adjustment slider 72 continues to be pulled and reaches the maximum advance position, the entire cam surface 65a is on the same plane as shown in FIG.

  In summary, when the adjustment slider 72 is moved back and forth, the adjustment contact 66 moves back and forth in accordance with the back and forth movement. The free end side of the cam member 65 is moved back and forth by the back and forth movement of the adjustment contact 66, and the difference in level of the step between the starting point and the final point of the cam surface 65a is adjusted. Therefore, also in the fourth embodiment shown in FIG. 14 and FIG. 15, the same operational effects as those of the third embodiment already described can be obtained. Note that a scale or the like indicating the position of the adjustment slider 72 relative to the outer peripheral surface of the adjustment slider 72 may be provided so that the user can visually recognize the current amount of feeding.

  In the embodiment shown in the figure, the adjustment slider 72 is configured as a separate component from the adjustment contact 66. However, the adjustment slider 72 and the adjustment contact 66 can be integrally formed as one component. Similarly, the cam member 65 and the adjustment contact 66 may be integrally formed into one part.

  Next, FIGS. 16 to 18 show a fifth embodiment of the mechanical pencil according to the present invention. 16 is a cross-sectional view of the configuration of the first half, FIG. 17 is a cross-sectional view of the configuration of the first half, and FIG. It is shown with the perspective view shown. Parts corresponding to the respective parts in the first embodiment shown in FIGS. 1 and 3 and the third embodiment shown in FIGS. 11 to 13 are denoted by the same reference numerals, and detailed description thereof is omitted. To do.

  In the fifth embodiment, the mechanical pencil is used in combination with the lead feeding mechanism described above in the first and second embodiments, and adjusts the feeding amount of the writing lead by the lead feeding mechanism. A feed amount adjusting mechanism 80 is provided. The feed amount adjustment mechanism 80 includes an adjustment port tip portion 81 that is similar to the feed amount adjustment mechanism 70 according to the fourth embodiment but has a different shape, and an adjustment slider 82 that is attached to the adjustment port tip portion 81.

  The feed amount adjustment mechanism 80 according to the fifth embodiment does not have the adjustment cap 72 and the adjustment contact 66, but instead slides the adjustment slider 82 in the axial direction, thereby forming the cam surface of the cam member 65. It differs from the feed amount adjusting mechanism 70 according to the fourth embodiment in that it is configured to directly adjust the level difference of the step between the starting point and the final point of 65a.

  The adjustment port tip 81 has an adjustment slide hole 81a extending in a rectangular shape in the longitudinal direction so as to be accessible to the internal cam member 65 in the cylindrical portion at the tip and the cylindrical portion formed larger in diameter following the rear portion. Is formed.

  The adjustment slider 82 is disposed through the adjustment slide hole 81 a of the adjustment port tip 81, and is attached to the adjustment port tip 81 so as to be slidable in the axial direction. A plurality of protrusions are provided on the outer surface of the adjustment slider 82 so that the user's finger does not slip when attached to the adjustment port 81, and the inner surface of the adjustment slider 82 extends inward and is a cam. A support member 82a that supports the member 65 from the surface opposite to the cam surface 65a is formed.

  The maximum forward position and the maximum backward position of the adjustment slider 82 with respect to the adjustment mouth tip 81 are regulated by the shape of the adjustment slide hole 81 a of the adjustment mouth tip 81. Specifically, when the adjustment slider 82 is at the maximum advance position in the axial direction, as shown in FIG. 17, the starting point and the final point of the cam surface 65a of the cam member 65 are at the same height, that is, The entire cam surface 65a is determined to be on the same plane.

  Therefore, the maximum feed amount that can be adjusted of the writing core 4 by the feed amount adjustment mechanism 80 is the distance between the maximum forward position and the maximum reverse position of the adjustment slider 82 with respect to the adjustment tip 81.

  Next, a method for adjusting the feeding amount of the writing core by the feeding amount adjusting mechanism 80 will be described. As described above, when the adjustment slider 82 is at the maximum forward position, the starting point and the final point of the cam surface 65a of the cam member 65 are at the same height. It only circulates on the same plane along. Therefore, the slider 3 does not move back in the axial direction based on the cushioning action of the writing lead by the writing action, and therefore the feeding amount of the writing lead 4 is zero.

  In this embodiment, when the adjustment slider 82 is retreated in the axial direction while being pressed by a finger, the cam surface 65a of the cam member 65 is also retreated in the axial direction while being supported by the support 82a. At this time, the cam member 65 is deformed so that the free end side is retracted so as to be pushed up from below with the fixed end by the connection portion 65b as a fulcrum. As a result, the cam member 65 forms a cam surface 65a that rises like the cam surface 8a in the first and second embodiments.

  On the other hand, when the adjustment slider 82 is pushed forward with the finger in the axial direction, the cam member 65 is restored by the action of the cam contact spring 20 or the combined spring 50 or by the elasticity of the cam member 65 itself. As a result, the free end moves forward with the fixed end of the connecting portion 65b as a fulcrum. When the adjustment slider 82 continues to advance and reaches the maximum advance position, the entire cam surface 65a is on the same plane as shown in FIG.

  In summary, when the adjustment slider 82 is moved back and forth, the free end side of the cam member 65 is also moved back and forth in accordance with the back and forth movement, and the difference in level of the step between the starting point and the final point of the cam surface 65a is adjusted. The Therefore, also in the fifth embodiment shown in FIGS. 16 to 18, it is possible to obtain the same operational effects as those of the third embodiment and the fourth embodiment already described. It should be noted that a scale or the like indicating the position of the adjustment slider 82 relative to the outer peripheral surface in the vicinity of the adjustment slide hole 81a of the adjustment port tip 81 may be provided so that the user can visually recognize the current amount of feeding.

  In the third to fifth embodiments described above, the starting point side of the cam surface 65a of the cam member 65 is set as the fixed end, and the final point side is retracted to adjust the feeding amount of the writing core 4. It was possible. However, the final point side of the cam surface 65a of the cam member 65 may be a fixed end and the starting point side may be advanced so that the feeding amount of the writing core 4 can be adjusted.

  In the first to fifth embodiments of the mechanical pencil according to the present invention, the writing core 4 is rotationally driven together with the ball chuck 9 that rotates by receiving the rotational driving force of the rotor 40 in the rotational driving mechanism 29. Was composed. However, as a matter of course, the lead feeding mechanism and the feeding amount adjusting mechanism in these embodiments can be applied to a mechanical pencil in which the writing lead is not rotationally driven. Hereinafter, the mechanical pencil mechanism in which the writing core is not rotationally driven will be briefly described by taking as an example the case where it is applied to the mechanical pencil in the third embodiment described above. The mechanism is referred to as a non-rotating drive mechanism 90.

  19 to 21 show a mechanical non-rotation drive mechanism 90 of a mechanical pencil in which the writing core 4 is not rotationally driven. FIG. 19 is a sectional view showing a mechanism in which the ball chuck 9 and the writing core 4 do not rotate despite the rotational driving action of the rotor 40, and FIG. FIG. 21 is a perspective view partially broken away of the front half of the non-rotating drive mechanism 90. FIG. Parts corresponding to the respective parts in the first embodiment shown in FIGS. 1 and 3 and the third embodiment shown in FIGS. 11 to 13 are denoted by the same reference numerals, and detailed description thereof is omitted. To do. The mechanical pencil having the non-rotation drive mechanism 90 is advantageous for a user who does not like the rotation of the writing core.

  The non-rotation drive mechanism 90 is similar to the first relay member 16, the second relay member 17, and the knock actuation cylinder 22 according to the first embodiment, but the first relay members have different shapes. 91, a second relay member 92, and a knock actuating cylinder 93.

  The first relay member 91 includes a sliding contact protrusion 91a formed in an annular shape on the outer peripheral surface thereof. Further, the first relay member 91 is provided with a pair of holding holes 91b that extend in the axial direction in the cylindrical portion on the rear end side of the sliding contact projection 91a and are disposed at positions facing the axial center. . The second relay member 92 includes, on its inner peripheral surface, a sliding contact groove 92a provided in an annular shape at a position corresponding to the sliding contact protrusion 91a of the first relay member 91 and complementary thereto. . The knock actuating cylinder 93 is provided with a pair of holding projections 93 a on the outer peripheral surface thereof at positions corresponding to the pair of holding holes 91 b of the first relay member 91.

  In the first embodiment, as described above, the first relay member 16 is fitted to the inner peripheral surface of the second relay member 17 formed in a cylindrical shape at a substantially central portion in the length direction. Attached. Therefore, the rotational movement by the relay pipe 18 connected to the rotation drive mechanism 29 rotates the writing core 4 together with the ball chuck 9 and the slider 3 via the second relay member 17 and the first relay member 16. However, in the non-rotating drive mechanism 90, the first relay member 91 and the second relay member 92 are not fitted, and therefore the rotational motion of the second relay member 92 is not transmitted to the first relay member 91. . That is, the rotational movement of the second relay member 92 is absorbed by the sliding between the sliding contact groove 92 a and the sliding contact protrusion 91 a of the first relay member 91, and thus the rotation of the first relay member 91. Movement is suppressed.

  Further, there is a possibility that rotational movement is transmitted by friction between the sliding contact projection 91 a and the sliding contact groove 92 a, but the holding projection 93 a of the knock actuating cylinder 93 is a pair of holding holes of the first relay member 91. By being arranged in 91b, transmission of rotational motion is prevented. That is, since the holding projection 93a of the knock actuating cylinder 93 extends into the pair of retaining holes 91b of the first relay member 91, the knock actuating cylinder 93 is allowed to slide in the axial direction but is axial. No rotational movement around is allowed. Further, the holding projection 93 a of the knock actuating cylinder 93 is adjusted to a height that does not contact the inner peripheral surface of the second relay member 92. Therefore, the holding projection 93a of the knock actuating cylinder 93 does not hinder the knocking operation.

1 Lead shaft (shaft tube)
2 Mouth (Cutipura)
DESCRIPTION OF SYMBOLS 3 Slider 3a Slider tip 3b Contact 4 Writing core 5 Tip pipe 6 Holding chuck 8 Cam member 8a Cam surface 8b Step 8c, 8d Two step 9 Ball chuck 10 Fastener 11 Chuck body 12 Ball 14 Chuck spring 16 First relay member 17 Second relay member 18 Relay pipe 20 Spring for cam contact 22 Knocking cylinder 23 Core case 25 Rear shaft (shaft cylinder)
26 outer shaft 29 rotation drive mechanism 30 shaft spring 32 return spring 34 knock cover 40 rotor 40a first cam surface 40b second cam surface 41 upper cam forming member (first cam forming member)
41a First fixed cam surface 42 Lower cam forming member (second cam forming member)
42a Second fixed cam surface 44 Cylinder member 45 Torque canceller 46 Cushion spring 50 Combined spring 51 Pipe support member

Claims (1)

A ball chuck that allows the writing core to advance and prevents retraction is housed in the shaft cylinder, and the axial retraction operation by the writing pressure received by the writing core gripped by the ball chuck and the axial direction by the release of the writing pressure. Comprising a lead feeding mechanism for feeding the writing lead forward in response to a forward movement;
A rotation driving mechanism for rotating the rotor in one direction in response to an axial retreat operation by the writing pressure received by the writing core held by the ball chuck and an axial advance operation by releasing the writing pressure; The core feeding mechanism is configured to receive the rotational driving force of the rotor in the rotational driving mechanism and to feed the writing core forward .
The core feeding mechanism has a cam surface that rises in an annular end surface along the circumferential direction, and a cam member that has a step in the axial direction between a starting point and a final point of the cam surface; The rotary drive mechanism is rotated by receiving the rotational driving force of the rotor, partly provided with a contact that contacts the cam surface of the cam member, and the shaft core portion is in sliding contact with the peripheral surface of the writing core And a slider with a holding chuck that holds the lead,
The writing core held in sliding contact with the holding chuck is moved by the forward movement of the slider when the slider abutting against the cam surface of the cam member falls into the step formed in the axial direction. A mechanical pencil that operates to pull out from the ball chuck .

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