JP2014210378A - Mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical pencil which has broad design width, which enables easy delivery of lead by one hand and which prevents lead from being delivered mistakenly while carried around.SOLUTION: A mechanical pencil is configured in such a manner that: a barrel 4 has a front barrel member 2 and a rear barrel member 3; a lead delivery mechanism is provided having a chuck 8 in the front barrel member 2; a cam mechanism having a sliding body 26 and a rotating body 25 is provided inside the rear barrel member 3; a weight body 20 is loosely fitted to a rear part of the chuck 8; and at the rotating body 25, a cam slope part 25b sliding with the sliding body 26 and an engaging part are provided.

Description

  The present invention relates to a mechanical pencil that feeds a core by relatively rotating a front shaft member and a rear shaft member that constitute a shaft cylinder, and a structure that can perform the core feeding even when the shaft cylinder is swung. About mechanical pencils.

  Conventionally, by rotating the rear shaft cylinder with respect to the front cylinder, the core feeding mechanism disposed in the front cylinder is operated to feed the core, and when not in use, the chuck opens the core. In addition, there is known a rotary pay-out mechanical pencil having a structure in which the function of disabling the lead is added (see Patent Document 1 and Patent Document 2). Further, a swing-out mechanical pencil having a structure in which the core is extended by the inertial force of the weight body by shaking the shaft cylinder is also well known (see Patent Document 3).

  The known rotary pay-out mechanical pencil has a structure in which the cam mechanism is operated by the relative rotation of the front shaft cylinder and the rear shaft cylinder to extend the core, so that the core supply mechanism built in the shaft cylinder is operated. The knock part is not exposed to the exterior, and it is excellent in appearance, but it is necessary to rotate by holding the front cylinder and the rear cylinder, and if you want to extend the core when writing, write The operation of interrupting and changing the shaft cylinder was required, and continuous smooth writing could not be performed. On the other hand, the swing-out mechanical pencil equipped with a knock type mechanical pencil has a weight body, and the weight body moves the chuck forward by swinging the shaft, so that the core can be fed out easily with one hand. Since the knocking part that moves back and forth protrudes from the rear end of the shaft tube, there is a design restriction. In addition, the swing-out mechanical pencil has the convenience that the lead is drawn out only by shaking the shaft tube, but there is a problem that the lead is also drawn out when the shaft tube is shaken when being carried.

Japanese Patent Publication No. 2-47358 JP 2000-335178 A No. 1-20150

  In view of the above problems, the present invention provides a mechanical pencil that can widen the design and can be easily extended with one hand, and that the lead is not accidentally extended when being carried. is there.

The present invention
“1. A shaft cylinder has a front shaft member and a rear shaft member, and by rotating the front shaft member and the rear shaft member relatively, the chuck provided in the shaft cylinder and the chuck In a mechanical pencil having a structure in which a lead feeding mechanism having a lead tank provided at the rear is operated and the lead in the lead tank is fed from a tip opening provided in front of the shaft tube, an inner shaft is provided in the shaft tube. A pressing body that is springed back by a spring is provided on the inner shaft so as to be able to move back and forth, the core tank is disposed in front of the pressing body, and is provided outside the core tank behind the chuck. A weight body capable of abutting on the abutting portion is disposed so as to be movable back and forth, and a sliding body that pushes the pressing body and a rotating body that slides on the sliding body are provided in the shaft cylinder, The rear shaft member is configured to rotate together with the rear shaft member, and the rotation of the rotating body. A cam mechanism is provided in which the sliding body is configured to be movable back and forth within the shaft cylinder, and the cam mechanism advances the sliding body by rotating the front shaft member and the rear shaft member relatively. The sliding body pushes the pressing body to advance the lead tank, advances the lead tank and the chuck together, feeds the lead from the tip, and shakes the shaft tube, A mechanical pencil having a structure in which a weight body abuts on the abutting portion provided behind the chuck, and the chuck is advanced by an inertial force of the weight body so that a lead is fed out from the front opening.
2. A cam protrusion is formed on the sliding body, and the cam protrusion is brought into contact with a cam contact portion formed on the rotating body, whereby the sliding body can be moved back and forth by a cam operation. The mechanical pencil according to claim 1, wherein the chuck is configured to open the lead when the cam projection is locked to the locking portion.
3. The mechanical pencil according to item 2, wherein the engaging part of the rotating body is a concave part or a flat part.
4). 4. The step according to claim 2 or 3, wherein a step portion is provided on a cam slope portion of the rotating body, and the chuck opens the core when the cam projection of the sliding body is in contact with the step portion. mechanical pencil.
5. The cam inclined surface portion of the rotating body has a first inclined portion and a second inclined portion, and the first inclined surface portion is formed by an inclined surface inclined with respect to a surface orthogonal to the rotation axis of the rotating body, The two inclined surfaces are formed so as to be further inclined with respect to the plane perpendicular to the rotation axis than the first inclined portion, and the slope change point of the boundary between the first inclined portion and the second inclined portion is defined as the step portion. 4. The mechanical pencil according to item 4.
6). 5. The mechanical pencil according to 4, wherein a convex portion or a concave portion is formed on the cam slope portion of the rotating body, and the convex portion or the concave portion is the stepped portion.
7). The mechanical pencil according to any one of 2 to 6, wherein a pressing elastic body is disposed between the pressing body and the core tank. It is.

  According to the present invention, the lead can be paid out by operating the lead feeding mechanism by relatively rotating the front shaft member and the rear shaft member. Can be paid out.

  Further, in the invention of item 2, since the chuck opens the core when the cam protrusion of the sliding body is locked to the locking portion of the rotating body, the weight body vibrates by shaking the shaft cylinder when it is carried. Thus, the lead can be prevented from being unintentionally drawn out, and an operation of returning the lead protruding from the front end into the front end at the end of writing can be easily performed. In the invention according to item 3, the locking portion of the rotating body is a concave recess, so that the locking state between the locking portion of the rotating body and the cam protrusion of the sliding body can be stabilized. Alternatively, when the locking portion of the rotating body is a flat portion parallel to the surface orthogonal to the rotation axis, the cam protrusion of the rotating body slides with the cam slope portion of the sliding body and moves to the locking portion. The transition will be smooth.

  According to the invention of item 4, when the front shaft member and the rear shaft member are relatively rotated to extend the core, the cam protrusion of the sliding body slides on the cam slope portion of the rotating body and contacts the stepped portion. By making it so that the chuck does not hold the lead open when it comes into contact, the lead is extended by the change in rotational resistance when the cam projection of the sliding member comes into contact with the step of the rotating member. Can be recognized by the user.

  In the invention according to item 5, when the front shaft member and the rear shaft member are relatively rotated to extend the core, the cam protrusion of the sliding body slides on the cam slope portion of the rotating body, and the slope change point When the contact is made, the rotation angle increases due to the steep angle of the second inclined portion with respect to the first inclined portion, and the end of the lead feeding operation can be recognized. Can be executed accurately.

  In the invention according to item 6, when the front shaft member and the rear shaft member are relatively rotated and the core is extended, the cam protrusion of the sliding body slides on the cam slope portion of the rotating body to project the convex portion or the concave portion. Since the rotation resistance changes and the end of the lead feeding operation can be recognized, the lead feeding by the turning operation can be executed accurately.

  As described in item 2 above, when the chuck is maintained with the lead open when being carried, the cam protrusion located at the position where the chuck has opened the lead is further slid onto the cam slant surface to lock the chuck. It is necessary to move to the department. In the invention according to item 7, when the chuck releases the lead and the advancement of the chuck and the lead tank stops, the pressing elastic body disposed between the pressing member and the lead tank contracts, so that the cam protrusion Becomes easy to be locked to the locking portion.

  The present invention can provide a mechanical pencil that has a wide design, can be easily drawn out with one hand, and does not accidentally be drawn out when being carried. .

It is a side view of the mechanical pencil of a present Example. It is sectional drawing in the writing state of a mechanical pencil. It is an internal peripheral surface expanded view of a rotating body. The sliding state of the cam contact part of a rotating body and the cam protrusion of a sliding body is represented. It is sectional drawing in the portable state of a mechanical pencil. It is a mechanical pencil in the state of replenishing the lead. It is an internal peripheral surface expanded view in the modification of a rotary body. It is an internal peripheral surface expanded view in the other modification of a rotary body.

  Next, the mechanical pencil of the present embodiment will be described with reference to FIGS. 1 to 6, but the present invention is not limited to the following embodiments. In addition, the side with the front end of the mechanical pencil is expressed as the front, and the opposite side is expressed as the rear.

  FIG. 1 is a side view of the mechanical pencil of this embodiment. The mechanical pencil 1 is configured by connecting a front shaft member 2 and a rear shaft member 3 to form a shaft cylinder 4. A front end member 5 is attached to a front end portion of the front shaft member 2, and a rear end portion of the rear shaft member 3 is attached. A tail crown 6 is attached, and a base portion 7 a of a clip 7 is sandwiched between the rear shaft member 3 and the tail crown 6.

  FIG. 2 is a cross-sectional view of the mechanical pencil of this embodiment. The lead feeding mechanism of the present embodiment is configured by dividing the front part of the chuck 8 into three parts, and the rear part of the chuck 8 is fitted to the front end part of the cylindrical connector 9. A lead tank 10 is loosely fitted to the rear portion of the connector 9, and a lead 11 is accommodated in the lead tank 10.

  Further, a fastener 12 is externally fitted to the head 8a of the chuck 8, and a chuck spring 14 is stretched between the connecting member 13 for receiving the fastener 12 and the connector 9 with a load of about 100 g. 8 is ejected rearward and the head 8 a is pressed against the fastener 12. Then, the chuck 8 is closed and the core 11 is held. A substantially conical tip port member 5 is detachably screwed to the front portion of the connecting member 13. A lead holder 15 that holds the lead 11 lightly is provided inside the tip member 5.

  Further, the front shaft member 2 is screwed to the rear portion of the connecting member 13 and fixed by an adhesive, and the front screw portion 16a of the inner shaft 16 is screwed and bonded to the rear screw portion 2a of the front shaft member 2. It is fixed by the agent. A cylindrical pressing body 17 is detachably and slidably inserted into the rear inner flange 16 c of the inner shaft 16, and a spring 18 is stretched between the inner shaft 16 and the pressing body 17. The pressing body 17 is repelled rearward. In this embodiment, the outer flange 17a and the slit 17b are formed at the tip of the pressing body 17, and the outer rod 17a is inserted into the rear inner rod 16c in a state where the tip is inserted into the rear inner flange 16c of the inner shaft 16. It will contact | abut to 16c and will be in a retaining state.

  Further, the lead tank 10 is slidably inserted into the front portion 17c of the pressing body 17, and a pressing elastic body 19 is provided between the rear end 10a of the lead tank 10 and a step portion 17d formed on the inner diameter of the pressing body 17. Is arranged. The entire length of the pressing elastic body 19 is shorter than the distance between the rear end 10a of the core tank 10 and the stepped portion 17d of the pressing body 17. Further, between the contact portion 9a formed at the rear of the connector 9 and the front end contact portion 17e of the pressing body 17, a metal weight body 20 is slid on the outer surface of the core tank 10 so as to move back and forth. It is.

  Further, the clip 7 is attached to the rear end of the rear shaft member 3, and the rear shaft member 3 and the base portion 7 a of the clip 7 are connected to each other by the tail crown mounting member 21 and the joint 22 housed behind the rear shaft member 3. It is sandwiched at the same time. Thereby, the clip 7 is fixed to the rear shaft member 3 so as not to rotate. Further, an eraser 23 is detachably attached to the opening 21a of the tail crown mounting member 21. To cover the eraser 23, the tail crown 6 is detachably screwed to the tail crown mounting member 21.

A front female screw portion 24a of the inner cylinder 24 is detachably screwed to the rear male screw portion 16b of the inner shaft 16, and the front end opening portion 22a of the joint 22 is loosely fitted to the rear end opening portion 14c of the inner shaft 16. The rotating body 25 is fitted so that the rear shaft member 3, the rotating body 25, and the clip 7 can rotate together.
Further, a sliding body 26 is disposed in front of the rotating body 25, and a cam contact portion 25a formed on the rotating body 25 is brought into contact with a cam protrusion 26a formed on the sliding body 26, whereby the sliding body 26 is operated as a cam. Enabled to move back and forth. The cam projection 26a of the sliding body 26 is inserted into a slit portion 24b drilled in the inner cylinder 24 so as to suppress the rotational movement of the sliding body 26 so that it can move back and forth. Then, the rear end portion 17f of the pressing body 17 and the front end portion 26d of the sliding body 26 come into contact with each other, and both the pressing body 17 and the sliding body 26 are ejected rearward by the spring 18. Further, the swinging of the rear shaft member 3 is restricted by covering the rear end portion 2 b of the front shaft member 2 with the front end portion 3 a of the rear shaft member 3.

  Further, as shown in FIGS. 2 and 3, the cam contact portion 25a formed on the rotating body 25 is inclined with respect to the cam inclined surface portion 25b inclined with respect to the surface orthogonal to the rotation axis CA and the surface orthogonal to the rotation axis CA. And a recessed portion 25c. The cam inclined surface 25b is further inclined with respect to the surface perpendicular to the rotational axis CA than the first inclined portion 25d inclined to the surface orthogonal to the rotational axis CA of the rotating body 25 and the first inclined portion 15d. By providing the two inclined portions 25e, a stepped portion was formed at the boundary between the first inclined portion 25d and the second inclined portion 25e, and the stepped portion was set as a slope change point 25f.

  As shown in FIG. 2, the sliding body 26 is formed with a circumferential groove 26b, and an annular ring member 27 is provided in the groove 26b. The ring member 27 is a member that is in contact with the inner surface 24c of the inner cylinder 24, and imparts an appropriate resistance when the front shaft member 2 and the rear shaft member 3 are relatively rotated. As such a ring member 27, for example, an O-ring formed of a synthetic rubber material that increases resistance can be used.

  Here, the position I of the cam projection 26a shown in FIGS. 2 and 4 indicates the writing state of the mechanical pencil of the present embodiment, and the cam wall 26c of the sliding body 26 and the wall portion 25g of the rotating body 25 are separated. It is in a contact state.

  Next, a description will be given of the first means for extending the lead from the writing state with reference to FIGS. In the mechanical pencil 1 of the present embodiment, when the rear shaft member 3 is rotated in one direction (the direction of arrow A in FIG. 1), the rotating body 25 is rotated together with the rear shaft member 3, and the front shaft member 3 and Since the cam projection 26a is regulated by the slit portion 24b of the integrated inner cylinder 24, the sliding body 26 does not rotate, and the cam projection 26a is advanced by the cam inclined surface portion 25b and moved to the position II shown in FIG. To do. That is, the cam protrusion 26a of the sliding body 26 and the first inclined portion 25d provided on the cam slope portion 25b of the rotating body 25 reach the inclination changing point 25f while abutting, and move the sliding body 26 forward. At this time, the pressing body 17 in which the advanced sliding body 26 is in contact is advanced. Then, the pressing body 17, the pressing elastic body 19, and the core tank 10 come into contact with each other, and the pressing elastic body 19 and the chuck spring 14 start to shrink, but the chuck spring 14 is stretched with an attachment load of about 100 g. Therefore, after the pressing elastic body 19 starts to shrink first and the spring load of the chuck spring 14 and the spring load of the pressing elastic body 19 are balanced, the chuck spring 14 and the pressing elastic body 19 are used for pressing. Since the elastic body 19 has a higher spring constant, the chuck spring 14 contracts more greatly, the lead tank 10 and the chuck 8 move forward, and the lead is fed out. Then, as shown in FIG. 4, the cam protrusion 26a is in the position II and abuts on the second inclined portion 25e. At this time, the end of the lead feeding operation can be recognized by increasing the rotational resistance for rotating the rear shaft member 3 with respect to the front shaft member 2.

Next, the second means in the case of extending the lead from the writing state will be described with reference to FIGS. In the mechanical pencil of this embodiment, when the shaft cylinder 4 is swung back and forth, the weight body 20 loosely fitted to the outside of the core tank 10 moves forward and comes into contact with the contact portion 9 a formed in the connector 9. Then, the connector 9 advances together with the chuck 8 by the impact force when the weight body 20 abuts, and a certain amount of the core 11 is drawn out. The advancement of the connector 9 is stopped when the step 9b of the connector contacts the step 13a of the connecting member 13.

  Next, a case where writing is finished and the portable state is set will be described with reference to FIGS. 2 and 4. The sliding body 26 at the position II shown in FIG. 4 moves forward while sliding the second inclined portion 25e of the rotating body 25 by further rotating the rear shaft member 3 in one direction, and moves the cam protrusion 26a. Although not shown, the chuck 8 located in front of the shaft cylinder 4 is maintained in a state in which the core 11 is opened by engaging with a recess 25c provided in the cam contact portion 25a of the rotating body 25 (position III in FIG. 4). I was able to. At this time, the pressing body 17 moves forward together with the sliding body 26 to advance the core tank 10, the connector 9, and the chuck 8. When the step 9 b of the connector 9 comes into contact with the step 13 a of the connecting member 13, the chuck 8. Since the pressing elastic body 19 is contracted, the pressing body 17 continues to advance, and the cam projection 26a of the sliding body 26 shifts to a position from II to III in FIG. It can be in a portable state. In the portable state, the chuck 8 cannot move forward, and the chuck 8 is in an open state, so the core 11 is not held. For this reason, even if the weight body 20 moves back and forth due to vibration during carrying, the lead is not drawn out, and the chuck 8 does not hold the lead 11, so the lead 11 from the tip 5 a of the tip member 12. Is protruding, the lead is held only by the lead holder 15 inside the tip member 5 and can be returned to the tip 5a by pushing the lead 11 protruding from the tip 5a backward. It is.

  As described above, when the rear shaft member 3 is rotated with respect to the front shaft member 2 and the core is extended, the cam protrusion 26a of the sliding body 26 comes into contact with the second inclined portion 25e of the rotating body 25, and the front The end of the lead feeding operation can be recognized by increasing the rotational resistance for rotating the rear shaft member 3 with respect to the shaft member 2. Accordingly, it is possible to suppress the rotation of the rear shaft member 3 with respect to the front shaft member 2 and to prevent the cam protrusion 26a of the sliding body 26 from being unintentionally locked to the concave portion 25c of the rotating body 25.

  Further, when returning from the carrying state to the writing state, the rear shaft member 3 is rotated in the other direction with respect to the front shaft member 2 from the state of FIG. 5 (in the direction of arrow B in FIG. 1). The engagement state between the cam projection 26a and the recess 25c of the rotating body 25 is released, and the cam projection 26a of the sliding body 26 is shifted from the position III to the position I in FIG. At this time, when the cam protrusion 26a of the sliding body 26 contacts the second inclined portion 25e of the rotating body 25, the cam protrusion 26a is shown in FIG. 4 by the elastic force of the chuck spring 14, the spring 18, and the pressing elastic body 19. It moves to the position of I, and it will be in the state which can write in FIG.

  Further, when the lead tank 10 is replenished with the lead, the sliding member is rotated from the state shown in FIG. 2 with respect to the front shaft member 2 in the other direction (in the direction of arrow B in FIG. 1). Since the cam wall 26c of 26 and the wall portion 25g of the rotating body 25 are in contact with each other and the rotation of the sliding body 26 in the direction of arrow C in FIG. 4 is restricted, the rear male screw portion 16b of the inner shaft 16 is restricted. And the front female screw portion 24a of the inner cylinder 24 are released, and the front shaft member 2 and the rear shaft member 3 can be divided as shown in FIG. In the state of FIG. 6, the pressing body 17 is exposed from the rear of the front shaft member 2, and the core can be replenished to the core tank 10 from the opening (not shown) of the rear end portion 17 f of the pressing body 17.

  FIG. 7 shows a modification of the rotating body. The cam contact portion 250a formed on the rotating body 250 is formed with a cam slope portion 250b inclined with respect to a surface orthogonal to the rotation axis CA and a flat portion 250c extending parallel to the surface orthogonal to the rotation axis CA. It is.

  In the modification of the rotating body shown in FIG. 7, when the rotating body 250 is formed with a flat portion 250 c parallel to a surface orthogonal to the rotation axis CA, when the above writing is finished and the portable body is put in a portable state, Transition when the cam protrusion 26a of the moving body 26 slides on the cam contact portion 250a of the rotating body 250 and moves from the cam inclined surface portion 250b to the flat portion 250c can be performed smoothly.

  FIG. 8 shows another modification of the rotating body. The cam contact portion 251a formed on the rotating body 251 has a cam slope portion 251b and a locking portion 251c. The cam slope portion 251b has a convex portion 251d (the form shown in FIG. 8A) or a concave portion 251e (FIG. 8B). The form shown in FIG.

  In another modification of the rotating body shown in FIG. 8, when the front shaft member 2 and the rear shaft member 3 are rotated to feed the core 11, the rear end of the cam protrusion 26 a is the cam slope portion 251 b of the rotating body 251. The end of the lead feeding operation can be recognized by abutting against the convex portion 251d or the concave portion 251e and the rotation resistance is changed, so that the lead feeding by the turning operation can be accurately executed.

1 ... mechanical pencil,
2 ... front shaft member, 2a ... rear screw part, 2b ... rear end part,
3 ... rear shaft member, 3a ... front end,
4 ... shaft tube,
5 ... tip member, 5a ... tip,
6 ... Tail crown,
7 ... clip, 7a ... base,
8 ... chuck, 8a ... head,
9 ... Connector, 9a ... Contact part, 9b ... Step part,
10 ... core tank, 10a ... rear end,
11 ... Core
12 ... Fasteners,
13 ... Connecting member, 13a ... Stepped part,
14 ... Chuck spring,
15 ... Core holder,
16 ... inner shaft, 16a ... front screw part, 16b ... rear male screw part,
16c ... rear inner cage,
17 ... Pressing body, 17a ... Border, 17b ... Slit, 17c ... Front part,
17d: Stepped portion, 17e: Front end contact portion, 17f: Rear end portion,
18 ... Spring,
19: elastic body for pressing,
20 ... weight body,
21 ... Tail crown mounting member, 21a ... Opening,
22 ... Fitting,
23 ... eraser,
24 ... inner cylinder, 24a ... front female screw part, 24b ... slit part, 24c ... inner surface,
25 ... Rotating body, 25a ... Cam contact part, 25b ... Cam slope part, 25c ... Recessed part,
25d ... 1st inclination part, 25e ... 2nd inclination part, 25f ... Inclination change point, 25g ... Wall part,
26 ... sliding body, 26a ... cam projection, 26b ... groove, 26c ... cam wall,
26d ... front end,
27. Ring member,
250 ... Rotating body, 250a ... Cam contact part, 250b ... Cam slope part, 250c ... Flat part,
251 ... Rotating body, 251a ... Cam contact part, 251b ... Cam slope part, 251c ... Locking part,
251d ... convex part, 251e ... concave part,
CA: Rotating shaft.

Claims (7)

  A shaft cylinder has a front shaft member and a rear shaft member, and a chuck provided in the shaft cylinder and a rear side of the chuck are provided by relatively rotating the front shaft member and the rear shaft member. In a mechanical pencil having a structure in which a lead feeding mechanism having a lead tank is operated and a lead in the lead tank is fed from a front opening provided in front of the shaft tube, an inner shaft is provided in the shaft tube, A pressing body that is springed back by a spring is provided on the inner shaft so as to be movable back and forth, the core tank is disposed in front of the pressing body, and an abutting portion that is provided outside the core tank and behind the chuck A weight body capable of abutting is provided so as to be movable back and forth, and a sliding body that pushes the pressing body and a rotating body that slides on the sliding body are provided in the shaft cylinder, and the rotating body and the rear shaft The members are configured to rotate together in conjunction with each other, and the rotation body rotates as described above. A cam mechanism is provided in which the moving body is configured to be movable back and forth in the shaft cylinder, and the cam mechanism advances the sliding body while rotating the front shaft member and the rear shaft member relative to each other. A sliding body pushes the pressing body to advance the lead tank, advances the lead tank and the chuck together, feeds the lead from the leading end, and shakes the shaft tube, thereby the weight body. Is a mechanical pencil having a structure that abuts against the abutting portion provided on the rear side of the chuck, advances the chuck by the inertial force of the weight body, and feeds the core from the front opening.   A cam protrusion is formed on the sliding body, and the cam protrusion is brought into contact with a cam contact portion formed on the rotating body, whereby the sliding body can be moved back and forth by a cam operation. The mechanical pencil according to claim 1, wherein the chuck opens the lead when the cam projection is locked to the locking portion.   The mechanical pencil according to claim 2, wherein the locking portion of the rotating body is a concave portion or a flat portion.   The step according to claim 2 or 3, wherein a step portion is provided on the cam slope portion of the rotating body, and the chuck opens the core when the cam projection of the sliding body is in contact with the step portion. The mechanical pencil described in 1.   The cam inclined surface portion of the rotating body has a first inclined portion and a second inclined portion, and the first inclined surface portion is formed by an inclined surface inclined with respect to a surface orthogonal to the rotation axis of the rotating body, The two inclined surfaces are formed so as to be further inclined with respect to the plane perpendicular to the rotation axis than the first inclined portion, and the slope change point of the boundary between the first inclined portion and the second inclined portion is defined as the step portion. The mechanical pencil according to claim 4.   The mechanical pencil according to claim 4, wherein a convex portion or a concave portion is formed on the cam slope portion of the rotating body, and the convex portion or the concave portion is the stepped portion.   The mechanical pencil according to any one of claims 2 to 6, wherein an elastic body for pressing is disposed between the pressing body and the core tank.

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