Mechanical pencil

Abstract

To realize a retractable unit that retracts the front end of a delivering unit from a barrel by using a simple structure.SOLUTION: A mechanical pencil 10 includes a barrel 20 having a front end opening 20a and a locking portion 24b formed on its inner surface, a delivering unit 30 that delivers a writing lead 100, and a retractable unit 50 that causes the front end of the delivering unit 30 to protrude and retract from the front end opening 20a. The retractable unit 50 includes a first operating body 60, a second operating body 70, and a rotating cam member 80. When the first operating body 60 is operated, the rotating cam member 80 rotates to one side in the circumferential direction dc and is locked by the locking portion 24b, and the front end protrudes from the front end opening 20a. When the second operating body 70 is operated, the rotating cam member 80 rotates to the other side in the circumferential direction dc, the locking of the rotating cam member 80 to the locking portion 24b is released, and the front end retracts from the front end opening 20a.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mechanical pencil. [Background technology]

[0002] There is known a knock-type mechanical pencil in which the tip of the lead-advancing mechanism can be caused to protrude from and retract into the barrel by knocking the operating part provided at the rear end. The mechanical pencil described in Patent Document 1 has a first operating member, which is a knock member protruding from the rear end of the barrel, and a second operating member, which is a clip. In this mechanical pencil, when the first operating member is knocked, the tip of the refill protrudes from the barrel. When the first operating member is further knocked, the writing lead is advanced from the refill. When the second operating member is slid forward, the tip of the refill retracts into the barrel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-203454 A Summary of the Invention [Problem to be solved by the invention]

[0004] The mechanical pencil disclosed in Patent Document 1 has a problem in that the mechanism for extending and retracting the tip of the refill is complicated and the number of parts is large.

[0005] The present invention has been made in consideration of the above points, and has an object to provide a retractable unit with a simple structure that causes the front end of the payout unit to protrude and retract from a barrel. [Means for solving the problem]

[0006] The mechanical pencil of the present invention is [1] A barrel having a front end opening and a locking portion formed on an inner surface thereof; A feeding unit that feeds out a writing lead; a retractable unit that causes a front end of the payout unit to protrude from and retract into the front end opening, The retractable unit includes a first operating body, a second operating body, and a rotating cam member, When the first operating body is operated, the rotating cam member rotates to one side in the circumferential direction and is engaged with the engaging portion, and the front end portion protrudes from the front end opening, When the second operating body is operated, the rotating cam member rotates to the other side in the circumferential direction, the rotating cam member is released from the locking portion, and the front end portion retracts from the front end opening.

[0007] The mechanical pencil of the present invention is [2] The second operating body includes a pressing surface facing forward and extending toward the other side in the circumferential direction as it moves rearward, the rotating cam member includes a first cam surface facing rearward and extending toward the one side in the circumferential direction as it moves rearward, and a second cam surface facing rearward and extending toward the other side in the circumferential direction as it moves rearward, The mechanical pencil described in [1], wherein when the front end of the advancing unit protrudes from the front end opening, at least a portion of the pressing surface and at least a portion of the second cam surface face each other in the axial direction.

[0008] The mechanical pencil of the present invention is [3] The rotating cam member has a plurality of protrusions provided on an outer circumferential surface of the rotating cam member and extending in an axial direction, the plurality of ridges include first ridges and second ridges, the first cam surface is disposed at a rear end of the first protrusion, The mechanical pencil according to [2], wherein the second cam surface is disposed at a rear end of the second protrusion.

[0009] The mechanical pencil of the present invention is [4] The mechanical pencil according to [3], wherein the plurality of ridges are arranged side by side at equal angular pitch in the circumferential direction.

[0010] The mechanical pencil of the present invention is [5] The engaging portion includes a pressure receiving surface facing forward and extending toward the one side in the circumferential direction as it moves rearward, The mechanical pencil according to any one of [2] to [4], wherein the rotating cam member is locked to the locking portion by the first cam surface coming into contact with the pressure-receiving surface. Effect of the Invention

[0011] According to the present invention, it is possible to realize a retractable unit that causes the front end of the payout unit to protrude and retract from the barrel with a simple structure. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing one embodiment of the present invention, and is a vertical sectional view showing an example of a mechanical pencil in an immersed state. [Diagram 2] FIG. 2 is an enlarged view showing the rear portion of the mechanical pencil in the immersed state. [Diagram 3] FIG. 3 is a vertical cross-sectional view showing the mechanical pencil of FIG. 1 in a projected state. [Figure 4] FIG. 4 is an enlarged view showing the rear portion of the mechanical pencil in the protruding state. [Diagram 5] FIG. 5 is an enlarged view showing the front portion of the mechanical pencil in the extended state. [Figure 6] FIG. 6 is a vertical cross-sectional view showing the mechanical pencil during the lead extension operation. [Figure 7] FIG. 7 is an enlarged view showing the front part of the mechanical pencil during the lead extension operation. [Figure 8] FIG. 8 is a perspective view showing the inner surface of the rear barrel of the mechanical pencil. [Figure 9] FIG. 9 is an exploded perspective view of a part of the retractable unit of the mechanical pencil. [Figure 10] FIG. 10 is a diagram for explaining an example of the operation of the disappearance unit. [Figure 11] FIG. 11 is a diagram for explaining an example of the operation of the disappearance unit. [Figure 12] FIG. 12 is a diagram for explaining an example of the operation of the disappearance unit. [Figure 13] FIG. 13 is a diagram for explaining an example of the operation of the disappearance unit. [Figure 14] FIG. 14 is a diagram for explaining an example of the operation of the disappearance unit. [Figure 15] FIG. 15 is a diagram for explaining an example of the operation of the disappearance unit. [Figure 16] FIG. 16 is a diagram for explaining an example of the operation of the disappearance unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to this specification, the scale and the aspect ratio are appropriately changed and exaggerated from those of the actual objects for the convenience of illustration and understanding.

[0014] In addition, terms used in this specification that specify shapes, geometric conditions, and the extent thereof, such as "parallel," "orthogonal," and "same," as well as values ​​of length and angle, are not to be bound by strict meanings, but are to be interpreted to include a range within which similar functions can be expected.

[0015] In this specification, the direction in which the central axis A of the mechanical pencil 10 extends (longitudinal direction, vertical direction in a longitudinal cross section) is the axial direction da, the direction perpendicular to the central axis A is the radial direction, and the direction along the circumference around the central axis A is the circumferential direction dc. In addition, along the axial direction da, the side that approaches the surface to be written on, such as a paper surface, when writing is the front, and the side that moves away from the surface to be written is the rear. In addition, along the radial direction, the direction toward the central axis A is the inside or inward, and the direction away from the central axis A is the outside or outward.

[0016] Fig. 1 is a diagram showing an embodiment of the present invention, and is a vertical cross-sectional view showing an example of a mechanical pencil 10 in a immersed state. Fig. 2 is an enlarged view showing a rear part of the mechanical pencil 10 in the immersed state.

[0017] The mechanical pencil 10 of this embodiment includes a barrel 20, a feed unit 30, and a retractable unit 50. The mechanical pencil 10 has a central axis A extending in the longitudinal direction. The barrel 20 extends in the axial direction da along the central axis A of the mechanical pencil 10. Therefore, the central axis of the barrel 20 coincides with the central axis A of the mechanical pencil 10. The barrel 20 may include a front shaft 22, a rear shaft 24, a grip member 26, and a tip member 28. The front end of the barrel 20 is provided with a front end opening 20a through which the writing core 100 can pass. In this embodiment, the front end opening 20a may be an opening formed at the front end of the tip member 28.

[0018] The front shaft 22 is a member that forms the front part of the mechanical pencil 10. The front shaft 22 has a substantially cylindrical shape. The front shaft 22 may be composed of one member or may be composed of multiple members. A grip member 26 may be disposed on the radially outer side of the front shaft 22. The grip member 26 is intended to be held by the user's fingers when writing with the mechanical pencil 10. The grip member 26 may be formed of an elastic member such as rubber or elastomer.

[0019] The rear shaft 24 is a member that forms the rear portion of the mechanical pencil 10. The rear shaft 24 is a member having a substantially cylindrical shape. The rear shaft 24 may be composed of one member or may be composed of multiple members. The front end of the rear shaft 24 is attached to the rear end of the front shaft 22, thereby connecting the rear shaft 24 to the front shaft 22. As an example, the rear shaft 24 is connected to the front shaft 22 by screwing a female thread portion formed on the inner periphery of the front end of the rear shaft 24 into a male thread portion formed on the outer periphery of the rear end of the front shaft 22.

[0020] The tip member 28 is a member that forms the tip portion of the mechanical pencil 10. The tip member 28 has a generally conical shape, and its outer diameter decreases toward the front. The rear end of the tip member 28 is attached to the front end of the front shaft 22, so that the tip member 28 is connected to the front shaft 22. As an example, the tip member 28 is connected to the front shaft 22 by screwing a female screw portion formed on the inner peripheral surface of the tip member 28 into a male screw portion formed on the outer peripheral surface of the front end of the front shaft 22. The tip member 28 has a step portion 28a provided on the inner surface. The step portion 28a is a portion that comes into contact with a shoulder portion 40a of the pen tip member 40 described later when the writing lead 100 is advanced.

[0021] Next, the retractable unit 50 will be described. FIG. 3 is a vertical cross-sectional view showing the mechanical pencil 10 of FIG. 1 in a protruding state. FIG. 4 is an enlarged view showing the rear part of the mechanical pencil 10 in a protruding state. FIG. 5 is an enlarged view showing the front part of the mechanical pencil 10 in a protruding state. FIG. 6 is a vertical cross-sectional view showing the mechanical pencil 10 during a lead-extending operation. FIG. 7 is an enlarged view showing the front part of the mechanical pencil 10 during a lead-extending operation. FIG. 8 is a perspective view showing the inner surface of the rear shaft 24 of the mechanical pencil 10. FIG. 9 is an exploded perspective view of a part of the retractable unit 50 of the mechanical pencil 10.

[0022] The retractable unit 50 has a function of causing the front end of the feeding unit 30 to protrude and retract from the front end opening 20a of the barrel 20. The retractable unit 50 switches the mechanical pencil 10 between a retracted state and a protruding state. The retracted state is a state in which the tip of the feeding unit 30 is retracted from the front end opening 20a (see FIG. 1). The protruding state is a state in which the tip of the feeding unit 30 protrudes from the front end opening 20a (see FIG. 3).

[0023] The retractable unit 50 includes a first operating body 60, a second operating body 70, a rotating cam member 80, and a locking portion 24b formed on the inner surface of the barrel 20 (rear axle 24). The retractable unit 50 may further include a holding member 90, a resilient member 52, a receiving member 54, a resilient member 56, and a groove portion 24a formed on the inner surface of the barrel 20 (rear axle 24).

[0024] The barrel 20 (rear barrel 24) has a groove 24a, a locking portion 24b, a slit 24d, and an inner surface step 24e. The groove 24a and the locking portion 24b are formed on the inner surface of the barrel 20.

[0025] The groove portion 24a extends linearly along the axial direction da. The groove portion 24a is configured to allow the protrusions 62b of the slide cam member 62 and the protrusions 82 of the rotating cam member 80, which will be described later, to enter from the front. The protrusions 62b and the protrusions 82 are movable in the axial direction da within the groove portion 24a. The barrel 20 has a plurality of groove portions 24a. The plurality of groove portions 24a may be arranged side by side in the circumferential direction dc with equal angular pitches.

[0026] The locking portion 24b is a portion that locks with the first protrusion 84 of the rotating cam member 80 in the protruding state. The locking portion 24b includes a pressure-receiving surface 24c that faces forward. The pressure-receiving surface 24c extends toward one side in the circumferential direction dc as it moves rearward. The pressure-receiving surface 24c may be a flat surface. In the protruding state, the first cam surface 84a of the rotating cam member 80 comes into contact with the pressure-receiving surface 24c, whereby the rotating cam member 80 is locked to the locking portion 24b.

[0027] The slit 24d extends linearly in the axial direction da. The slit 24d penetrates the barrel 20 (rear axle 24) in the radial direction. A rotation stopper 72 (described later) of the second operating body 70 is disposed in the slit 24d. The rotation stopper 72 is movable in the axial direction da within the rear axle 24.

[0028] The inner surface step 24e is a step formed on the inner surface of the barrel 20 (rear barrel 24). The inner surface step 24e includes a surface facing forward. In the retracted state (see FIGS. 1 and 2), the shoulder 64 of the slide cam member 62 contacts the inner surface step 24e.

[0029] The first operating body 60 is operated by the user when protruding the front end of the feeding unit 30 from the front end opening 20a of the barrel 20. In other words, in the retractable unit 50, the first operating body 60 is operated by the user when switching the mechanical pencil 10 from a retracted state to a protruding state. The first operating body 60 is also operated by the user when protruding the writing lead 100. The first operating body 60 is arranged so as to be movable back and forth and non-rotatable with respect to the barrel 20 (rear barrel 24). The first operating body 60 may include a slide cam member 62, an erasing member 66, and a cap 68.

[0030] The slide cam member 62 has a function of pressing the core pipe 31 forward when the first operating body 60 is pressed forward. In the illustrated example, the slide cam member 62 is a member having a substantially cylindrical shape. The slide cam member 62 may include a front cam 62a, a protrusion 62b, an inner flange portion 62c, an erasing member holding portion 62e, and a shoulder portion 64.

[0031] The front cam 62a is disposed on the front surface of the slide cam member 62. The front cam 62a is configured to be engageable with the rear cam 80a of the rotating cam member 80. The front cam 62a may have a shape that allows it to come into contact with the rear cam 80a with almost no gap. That is, the front cam 62a may have a shape complementary to the rear cam 80a. The front cam 62a may include a first surface that faces one side in the circumferential direction dc as it moves rearward, and a second surface that faces the other side in the circumferential direction dc as it moves rearward. The front cam 62a may include a plurality of first surfaces and a plurality of second surfaces. The plurality of first surfaces and the plurality of second surfaces may be alternately arranged in the circumferential direction dc.

[0032] The ridges 62b are disposed on the outer peripheral surface of the slide cam member 62. The ridges 62b extend linearly in the axial direction da. The slide cam member 62 may have a plurality of ridges 62b. The plurality of ridges 62b may be arranged side by side in the circumferential direction dc with equal angular pitches. The ridges 62b are positioned within the grooves 24a of the barrel 20. In particular, the ridges 62b are always positioned within the grooves 24a of the barrel 20 whether in the retracted state or the protruding state. This allows the slide cam member 62 to move back and forth relative to the barrel 20 but not to rotate.

[0033] The inner flange 62c is disposed on the inner circumferential surface of the slide cam member 62. The inner flange 62c is an annular protrusion extending along the circumferential direction dc. In the protruding state (see Figs. 3 to 5), the rear end of the core pipe 31 may contact the inner flange 62c. In addition, in the protruding state, a gap may be formed between the rear end of the core pipe 31 (described later) and the inner flange 62c. In this case, when the first operating body 60 is pressed forward to advance the writing core 100, the inner flange 62c contacts the rear end of the core pipe 31. An opening 62d is formed on the inside of the inner flange 62c. By removing the cap 68 and the eraser 66 from the slide cam member 62, the writing core 100 can be refilled into the core pipe 31 through the opening 62d.

[0034] The erasing member holding portion 62e is a portion that holds the erasing member 66. The erasing member holding portion 62e is a recess that opens to the rear. The erasing member holding portion 62e is disposed behind the inner flange portion 62c.

[0035] The shoulder portion 64 is a step portion formed on the outer circumferential surface of the slide cam member 62. The shoulder portion 64 includes a surface facing rearward. In the retracted state (see FIGS. 1 and 2), the shoulder portion 64 comes into contact with the inner surface step portion 24e of the barrel 20 (rear barrel 24).

[0036] The erasing member 66 is a member for rubbing handwriting to erase the handwriting. The erasing member 66 is, for example, a rubber eraser. The erasing member 66 is disposed in the erasing member holding portion 62e of the slide cam member 62. The cap 68 is a member attached to the rear end of the slide cam member 62 so as to cover the erasing member 66, and is intended to be contacted and pressed by the user's finger or the like when the user presses the first operating body 60 forward.

[0037] The second operating body 70 is operated by the user when retracting the front end of the feeding unit 30 from the front end opening 20a of the barrel 20. In other words, in the retractable unit 50, the second operating body 70 is operated by the user when switching the mechanical pencil 10 from a protruding state to a retracted state. The second operating body 70 may include a rotation stopper 72 and a pressing portion 74. The second operating body 70 is configured to be movable in the axial direction da.

[0038] The anti-rotation portion 72 has a function of preventing the mechanical pencil 10 from rolling when the mechanical pencil 10 is laid down on a table or the like. A part of the anti-rotation portion 72 is located within the slit 24d of the barrel 20 (rear barrel 24). A part of the anti-rotation portion 72 protrudes radially outward from the barrel 20 (rear barrel 24). The anti-rotation portion 72 is movable within the rear barrel 24 in the axial direction da.

[0039] The pressing portion 74 is a portion that presses a second cam surface 86a (described later) of the rotating cam member 80 when the second operating body 70 moves forward. The pressing portion 74 may be disposed inside any one of the grooves 24a of the barrel 20 (rear barrel 24). The pressing portion 74 may also be disposed inside a groove provided in the barrel 20 (rear barrel 24) separate from the groove 24a. The pressing portion 74 includes a pressing surface 74a. The pressing surface 74a is a surface that comes into contact with the second cam surface 86a when the pressing portion 74 presses the second cam surface 86a. The pressing surface 74a is a surface that faces forward and extends toward the other side in the circumferential direction dc as it approaches the rear. The pressing surface 74a may be a flat surface.

[0040] The rotating cam member 80 is disposed in the shaft cylinder 20 so as to be rotatable about the central axis A and movable in the axial direction da. The rotating cam member 80 has a substantially cylindrical shape. The rotating cam member 80 includes a first cam surface 84a and a second cam surface 86a. The rotating cam member 80 may further include a rear cam 80a and a protrusion 82.

[0041] The rear cam 80a is disposed on the rear surface of the rotating cam member 80. The rear cam 80a is configured to be engageable with the front cam 62a of the slide cam member 62. The rear cam 80a may have a shape that allows it to come into contact with the front cam 62a with almost no gap. That is, the rear cam 80a may have a shape complementary to the front cam 62a. The rear cam 80a may include a first surface that faces one side in the circumferential direction dc as it moves rearward, and a second surface that faces the other side in the circumferential direction dc as it moves rearward. The rear cam 80a may include a plurality of first surfaces and a plurality of second surfaces. The plurality of first surfaces and the plurality of second surfaces may be alternately arranged in the circumferential direction dc. In the protruding state, the first surface of the front cam 62a and the first surface of the rear cam 80a may come into contact with each other while facing each other. Also, in the protruding state, the second surface of the front cam 62a and the second surface of the rear cam 80a may come into contact with each other while facing each other.

[0042] The ridges 82 are disposed on the outer peripheral surface of the rotating cam member 80. The ridges 82 extend linearly in the axial direction da. The rotating cam member 80 may have a plurality of ridges 82. The plurality of ridges 82 may be disposed side by side in the circumferential direction dc with equal angular pitches. The plurality of ridges 82 may include a first ridge 84 and a second ridge 86. As an example, the plurality of ridges 82 may include a plurality of first ridges 84 and one second ridge 86.

[0043] The first ridge 84 includes a first cam surface 84a. The first cam surface 84a is disposed at the rear end of the first ridge 84. The first cam surface 84a extends toward one side in the circumferential direction dc as it moves rearward. In the protruding state, the first cam surface 84a comes into contact with the pressure-receiving surface 24c of the barrel 20, whereby the rotating cam member 80 is locked to the locking portion 24b. The first cam surface 84a may be a flat surface.

[0044] The second protrusion 86 includes a second cam surface 86a. When the second operating body 70 moves forward, the second cam surface 86a comes into contact with the pressing surface 74a of the second operating body 70 and receives a pressing force from the pressing surface 74a. The second cam surface 86a is disposed at the rear end of the second protrusion 86. The second cam surface 86a extends toward the other side in the circumferential direction dc as it moves rearward. That is, the second cam surface 86a extends at an incline toward the opposite side to the first cam surface 84a. The second cam surface 86a may be a flat surface. In the protruding state, at least a portion of the pressing surface 74a and at least a portion of the second cam surface 86a face each other in the axial direction da (see FIG. 13).

[0045] In the recessed state, the ridge 82 is located in the groove 24a of the barrel 20 (see FIG. 10). At this time, the rotating cam member 80 is movable back and forth relative to the barrel 20 but is unable to rotate. In addition, in the protruding state, the ridge 82 is engaged with the locking portion 24b of the barrel 20 (see FIG. 13). At this time, the first cam surface 84a is pressed against the pressure-receiving surface 24c of the locking portion 24b by the elastic force of the elastic member 56. This makes the rotating cam member 80 unable to rotate relative to the barrel 20 and restricts its backward movement relative to the barrel 20.

[0046] The holding member 90 is a member that holds the rotating cam member 80. The holding member 90 has a substantially cylindrical shape. The rotating cam member 80 is disposed on the outside of the holding member 90. The holding member 90 may include a flange portion 92, an inner surface rib 94, and an inward protrusion portion 96.

[0047] The flange portion 92 is disposed on the outer peripheral surface of the front portion of the holding member 90. The flange portion 92 is an annular protrusion extending along the circumferential direction dc. The flange portion 92 has a receiving portion 92a. The receiving portion 92a is a surface facing forward and receives the elastic force of the elastic member 56. The front end portion of the rotating cam member 80 contacts the rear surface of the flange portion 92.

[0048] The inner rib 94 is disposed on the inner peripheral surface of the holding member 90. The inner rib 94 extends linearly along the axial direction da. The holding member 90 has a plurality of inner ribs 94. The plurality of inner ribs 94 may be arranged side by side in the circumferential direction dc at equal angular pitches. A tail plug 47 of the payout unit 30, which will be described later, comes into contact with the front end of the inner rib 94.

[0049] The inward protrusion 96 is disposed on the inner circumferential surface of the rear portion of the holding member 90. The inward protrusion 96 is an annular protrusion extending along the circumferential direction dc. In this embodiment, the inward protrusion 96 is disposed rearward of the inner surface rib 94. An opening 96a is formed on the inside of the inward protrusion 96. The core pipe 31 is disposed within the opening 96a.

[0050] A resilient member 52 is disposed between the first operating body 60 and the holding member 90. In particular, the resilient member 52 is disposed between the slide cam member 62 and the holding member 90. The resilient member 52 is, for example, a coil spring. In the retracted state, the resilient member 52 is compressed between the slide cam member 62 and the holding member 90. At this time, the resilient member 52 biases the first operating body 60 backward against the holding member 90.

[0051] A receiving member 54 is disposed inside the barrel 20. A part of the receiving member 54 may come into contact with the rear end of the front barrel 22, thereby preventing the receiving member 54 from moving forward. The receiving member 54 may also be fixed to the barrel 20. The receiving member 54 includes a receiving portion 54a. The receiving portion 54a is a portion that receives the elastic force of the elastic member 56.

[0052] A resilient member 56 is disposed in a compressed state between the holding member 90 and the receiving member 54. In particular, the resilient member 56 is disposed between the receiving portion 92a of the holding member 90 and the receiving portion 54a of the receiving member 54. The resilient member 52 is, for example, a coil spring. The resilient member 56 biases the holding member 90, the rotating cam member 80, and the first operating body 60 rearward. As a result, in the retracted state, the shoulder portion 64 of the first operating body 60 (slide cam member 62) is pressed against the inner surface step portion 24e of the barrel 20 (rear barrel 24).

[0053] Next, the feeding unit 30 of the mechanical pencil 10 will be described mainly with reference to Figures 3 and 5. In a protruding state (see Figure 3), the feeding unit 30 has a function of feeding the writing lead 100 forward from the front end opening 20a of the barrel 20 by operation by the user. The feeding unit 30 of this embodiment includes a first operating body 60, a lead pipe 31, a chuck 33, a connector 35, a resilient member 37, a receiving member 39, a pen tip member 40, a fastener 41, a lead holder 43, an outer pipe 45, a tail plug 47, and a weight body 49.

[0054] The core pipe 31 is a member that stores the writing lead 100 therein. In addition, in this embodiment, the core pipe 31 also has a function of transmitting a pressing force from the first operating body 60 to the connector 35 when the user presses the first operating body 60 forward. The core pipe 31 has a substantially cylindrical shape. The core pipe 31 may be made of, for example, resin. The core pipe 31 is disposed through the opening 96a of the holding member 90. A slight gap is formed between the outer peripheral surface of the core pipe 31 and the opening 96a of the holding member 90 in the radial direction, and the core pipe 31 can easily move in the axial direction da relative to the holding member 90. The rear end of the core pipe 31 is disposed within the first operating body 60.

[0055] The chuck 33 is a member that grips the writing lead 100. The chuck 33 can move back and forth together with the lead pipe 31 and the connector 35. The connector 35 is a member that connects the lead pipe 31 and the chuck 33. In the illustrated example, the rear end of the connector 35 is inserted into the front end of the lead pipe 31, thereby fixing the connector 35 to the lead pipe 31. In addition, the rear end of the chuck 33 is inserted into the front end of the connector 35, thereby fixing the chuck 33 to the connector 35.

[0056] A resilient member 37 is disposed in front of the connector 35. The resilient member 37 is, for example, a coil spring. The resilient member 37 is disposed between the front end of the connector 35 and a receiving member 39. The receiving member 39 is a member that receives the resilient force of the resilient member 37 when the writing lead 100 is extended.

[0057] The pen tip member 40 is a member that holds the front portion of the writing lead 100. The rear end of the pen tip member 40 is attached to the front end of the receiving member 39, thereby connecting the pen tip member 40 to the receiving member 39. As an example, a male threaded portion formed on the outer periphery of the front end of the receiving member 39 is screwed into a female threaded portion formed on the inner periphery of the rear end of the pen tip member 40, thereby connecting the pen tip member 40 to the receiving member 39. The pen tip member 40 has a shoulder portion 40a. The shoulder portion 40a comes into contact with the step portion 28a of the tip member 28 when the writing lead 100 is advanced.

[0058] The fastener 41 is an annular part located radially outward from the front portion of the chuck 33. The rear end of the fastener 41 abuts against the receiving member 39, thereby restricting rearward movement of the fastener 41. The lead holder 43 is located in front of the chuck 33 and is a member that abuts against the outer surface of the writing lead 100 to hold the writing lead 100. The lead holder 43 is formed of an elastic member such as rubber, and prevents the writing lead 100 from moving in the axial direction da when the chuck 33 is not gripping the writing lead 100. The fastener 41 and the lead holder 43 are located within the pen tip member 40.

[0059] The outer pipe 45 is disposed outside the core pipe 31. The outer pipe 45 has a substantially cylindrical shape. The front end of the outer pipe 45 is attached to the receiving member 39. For example, the rear end of the receiving member 39 may be press-fitted into the front end of the outer pipe 45, thereby attaching the outer pipe 45 to the receiving member 39. The outer pipe 45 may be formed of, for example, resin. The rear end of the outer pipe 45 is disposed in the holding member 90. In particular, the rear end of the outer pipe 45 is press-fitted into the holding member 90 from the front, whereby the outer pipe 45 is fixed to the holding member 90.

[0060] The weight body 49 is a cylindrical member extending in the axial direction da. The weight body 49 is disposed outside the core pipe 31 so as to surround the core pipe 31. In particular, the weight body 49 may be disposed between the core pipe 31 and the outer pipe 45. The weight body 49 is formed of a material having a relatively high density, for example, a metal material. A slight gap is formed between the weight body 49 and the core pipe 31 in the radial direction, and the weight body 49 can easily move in the axial direction da relative to the core pipe 31. In particular, when the user shakes the mechanical pencil 10 along the axial direction da, the weight body 49 moves in the axial direction da relative to the core pipe 31.

[0061] The connector 35 has an abutment portion 35a that protrudes radially outward beyond the outer circumferential surface of the core pipe 31. When the weight body 49 moves forward and collides with the abutment portion 35a of the connector 35 from behind, the impact load acting on the connector 35 from the weight body 49 causes the connector 35 to move forward.

[0062] A tail plug 47 is attached to the rear end of the outer pipe 45. The tail plug 47 has a function of preventing the weight body 49 from slipping out rearward of the outer pipe 45. Therefore, the tail plug 47 is fixed to the outer pipe 45. For example, the front end of the tail plug 47 may be press-fitted into the rear end of the outer pipe 45, thereby fixing the tail plug 47 to the outer pipe 45. Note that a slight radial gap is formed between the inner surface of the tail plug 47 and the outer surface of the core pipe 31, and the core pipe 31 can easily move in the axial direction da relative to the tail plug 47. When the outer pipe 45 is disposed in the holding member 90, the tail plug 47 is in contact with the front end of the inner rib 94 of the holding member 90.

[0063] When the first operating body 60 is not pressed forward in the protruding state, as shown in Fig. 4, a gap is formed in the axial direction da between the rear end of the core pipe 31 and the inner flange 62c of the slide cam member 62. When the first operating body 60 is not pressed forward, the outer surface of the front portion of the chuck 33 abuts against the fastener 41 from the inside. Therefore, the front portion of the chuck 33 is prevented from opening outward in the radial direction. This allows the front portion of the chuck 33 to grip the writing core 100.

[0064] When the writing lead 100 is advanced by the advancing unit 30, the first operating body 60 is pressed forward by the user in the protruding state shown in Figures 3 to 5. When the first operating body 60 is pressed forward, the slide cam member 62 moves forward while compressing the elastic member 52, and the rear end of the lead pipe 31 and the inner flange portion 62c of the slide cam member 62 come into contact with each other.

[0065] As described above, the outer pipe 45 is fixed to the holding member 90. When the first operating body 60 is pressed further forward, the first operating body 60, the core pipe 31, the connector 35, the chuck 33 and the fastener 41 move forward relative to the outer pipe 45, the receiving member 39 and the pen tip member 40 while compressing the resilient members 37 and 52. When the chuck 33 moves forward, the writing core 100 held by the chuck 33 moves forward, and the writing core 100 is advanced forward from the front end of the pen tip member 40. When the fastener 41 comes into contact with a step provided on the inner surface of the pen tip member 40, the fastener 41 stops moving forward any further.

[0066] When the first operating body 60 is further pressed forward, the chuck 33 moves forward relative to the fastener 41. As a result, the front part of the chuck 33 is released from the fastener 41. As a result, the front part of the chuck 33 opens radially outward, and the writing core 100 held by the front part of the chuck 33 is released. At this time, the writing core 100 is held by the lead holder 43. When the first operating body 60 is further pressed forward, the front cam 62a of the slide cam member 62 comes into contact with the rear cam 80a of the rotating cam member 80, and the first operating body 60 pushes the rotating cam member 80, the holding member 90, the outer pipe 45, the receiving member 39, and the pen tip member 40 forward. As a result, the entire payout unit 30 moves forward while compressing the elastic member 56. When the first operating body 60 is further pressed forward, the shoulder portion 40a of the pen tip member 40 comes into contact with the step portion 28a of the tip member 28. This prevents the pen tip member 40 from moving forward any further.

[0067] When the user releases the pressure on the first operating body 60, the first operating body 60, the core pipe 31, the connector 35, the chuck 33 and the fastener 41 move backward due to the elastic force of the elastic member 56 and the elastic member 37. When the rear end of the fastener 41 contacts the front end of the receiving member 39, the fastener 41 does not move backward any further. When the chuck 33 moves further backward, the front part of the chuck 33 moves toward the inside of the fastener 41 and abuts against the fastener 41 to grip the writing core 100. At this time, since the writing core 100 is held by the core holder 43, the backward movement of the writing core 100 is suppressed. In this way, in the writing instrument of this embodiment, the writing core 100 is advanced forward from the front end of the pen tip member 40.

[0068] In the mechanical pencil 10 of this embodiment, the user can also advance the writing lead 100 by shaking the mechanical pencil 10 along the axial direction da. When the user shakes the mechanical pencil 10 along the axial direction da, the weight body 49 moves forward and collides with the abutment portion 35a of the connector 35 with force. This causes the core pipe 31, the connector 35, and the chuck 33 to move forward while compressing the resilient member 37. In particular, the core pipe 31, the connector 35, and the chuck 33 move relative to the pen tip member 40. At this time, the shoulder portion 40a of the pen tip member 40 does not need to contact the step portion 28a of the tip member 28.

[0069] When the chuck 33 moves forward, the writing core 100 held by the chuck 33 moves forward, and the writing core 100 is extended forward from the front end of the pen tip member 40. When the chuck 33 moves further forward, the front part of the chuck 33 moves forward relative to the fastener 41. This causes the front part of the chuck 33 to open radially outward, and the writing core 100 held by the front part of the chuck 33 is released. At this time, the writing core 100 is held by the lead holder 43.

[0070] When the pressure on the connector 35 by the weight 49 is released, the elastic force of the elastic member 37 moves the core pipe 31, the connector 35, and the chuck 33 rearward. When the chuck 33 moves rearward, the front portion of the chuck 33 moves toward the inside of the fastener 41 and abuts against the fastener 41 to grip the writing core 100. At this time, since the writing core 100 is held by the lead holder 43, rearward movement of the writing core 100 is suppressed. With the writing instrument of this embodiment, even in this manner, the writing core 100 can be advanced forward from the front end of the pen tip member 40.

[0071] In addition, when the mechanical pencil 10 is carried in the immersed state, if the mechanical pencil 10 is shaken, the weight body 49 may move in the front-rear direction. In this case, the weight body 49 may collide with the abutment portion 35a of the connector 35, and the writing lead 100 may be unintentionally advanced. In this embodiment, when the resilient member 37, the resilient member 52, and the resilient member 56 are incorporated in the mechanical pencil 10, the resilient force of the resilient member 56 is set to be greater than the sum of the resilient forces of the resilient member 37 and the resilient member 52. In the immersed state, the first cam surface 84a of the rotating cam member 80 is not engaged with the engaging portion 24b of the shaft tube 20. In this case, the large resilient force of the resilient member 56 causes the holding member 90 and the rotating cam member 80 to retreat significantly. As a result, the resilient member 52 arranged between the first operating body 60 and the holding member 90 is compressed.

[0072] In addition, since the outer pipe 45 is fixed to the holding member 90, the outer pipe 45, the receiving member 39, the pen tip member 40, and the fastener 41 move backward relative to the core pipe 31, the connector 35, and the chuck 33. At this time, the front part of the chuck 33 is positioned forward relative to the fastener 41. As a result, the front part of the chuck 33 opens radially outward, and the writing core 100 held by the front part of the chuck 33 is released. In this state, since the chuck 33 does not hold the writing core 100, even if the weight body 49 collides with the abutment part 35a of the connector 35, the writing core 100 is not advanced forward. Therefore, in such a mechanical pencil 10, when the mechanical pencil 10 is carried in a immersed state, the writing core 100 is prevented from being unintentionally advanced due to the forward and backward movement of the weight body 49.

[0073] Next, an example of the operation of the retractable unit 50 will be described with reference to Figs. 10 to 16. Figs. 10 to 16 are developments showing a part of the retractable unit 50 in a state where one place in the circumferential direction dc of the mechanical pencil 10 is cut and opened along a plane extending in the axial direction da and radial direction. Figs. 10 to 16 show the retractable unit 50 as seen from the outside in the radial direction. Also, in Figs. 10 to 16, the rotating cam member 80 is shown by a solid line, the second operating body 70 by a dashed line, the slide cam member 62 by a dashed line, and the shaft tube 20 by a dashed line.

[0074] In the retractable unit 50 of this embodiment, by operating the first operating body 60, the rotating cam member 80 rotates to one side in the circumferential direction dc and is locked to the locking portion 24b, and the front end protrudes from the front end opening 20a. Also, by operating the second operating body 70, the rotating cam member 80 rotates to the other side in the circumferential direction dc, and the locking of the rotating cam member 80 to the locking portion 24b is released, and the front end retracts from the front end opening 20a.

[0075] First, referring to Figs. 10 to 13, an example of the operation of the retractable unit 50 when the tip of the payout unit 30 is protruded from the front end opening 20a of the barrel 20 will be described. Fig. 10 shows a part of the retractable unit 50 in a retracted state. The protrusion 62b of the slide cam member 62 is always positioned within the groove 24a of the barrel 20 in both the retracted state and the protruding state. This allows the slide cam member 62 to move back and forth relative to the barrel 20 but not to rotate. In the retracted state, the protrusion 82 of the rotating cam member 80 is positioned within the groove 24a of the barrel 20. At this time, the rotating cam member 80 is movable back and forth relative to the barrel 20 but not to rotate.

[0076] When the operator presses the first operating body 60 forward, the resilient member 56 is compressed, and the first operating body 60, the rotating cam member 80, and the holding member 90 move forward (see FIG. 11). As a result, the protrusion 82 of the rotating cam member 80 comes out forward from the groove portion 24a of the barrel 20. In this state, the rotating cam member 80 becomes rotatable in the circumferential direction relative to the barrel 20. At this time, the tip of the payout unit 30 protrudes from the front end opening 20a of the barrel 20.

[0077] The rotating cam member 80 receives the elastic force of the elastic member 56 via the holding member 90. Due to this elastic force, the rear cam 80a of the rotating cam member 80 slides against the front cam 62a of the slide cam member 62. In particular, the first surface of the rear cam 80a slides against the first surface of the front cam 62a. This causes the rotating cam member 80 to rotate toward one side in the circumferential direction dc. Thereafter, the rotation of the rotating cam member 80 stops in a state in which the first surface of the rear cam 80a and the first surface of the front cam 62a face each other and come into contact with each other, and the second surface of the rear cam 80a and the second surface of the front cam 62a face each other and come into contact with each other (see FIG. 12). At this time, a part of the first cam surface 84a of the rotating cam member 80 faces a part of the pressure receiving surface 24c of the locking portion 24b in the axial direction da. In this case, the first cam surface 84a and the pressure receiving surface 24c may or may not come into contact with each other.

[0078] When the operator releases the pressure on the first operating body 60, the elastic force of the elastic member 56 moves the holding member 90 and the rotating cam member 80 backward, and the first cam surface 84a of the rotating cam member 80 and the pressure receiving surface 24c of the rear shaft 24 come into contact with each other. After that, the first cam surface 84a slides against the pressure receiving surface 24c. This causes the rotating cam member 80 to rotate toward one side in the circumferential direction dc. When the side surface of the first protrusion 84 comes into contact with the side surface of the rear shaft 24, the rotation of the rotating cam member 80 stops (see FIG. 13). That is, the rotating cam member 80 is locked by the locking portion 24b. In this state, the backward movement of the rotating cam member 80 and the holding member 90 is restricted. Therefore, the tip of the feeding unit 30 remains protruding from the front end opening 20a of the barrel 20 and does not retract. That is, the mechanical pencil 10 is in a protruding state. At this time, the slide cam member 62 is urged rearward against the holding member 90 by the resilient force of the resilient member 52. Therefore, the slide cam member 62 separates from the rotating cam member 80 and moves rearward.

[0079] Next, with reference to Figs. 14 and 15, the operation of the retractable unit 50 when the writing lead 100 is advanced will be described. When the operator presses the first operating body 60 forward in the protruding state, the first operating body 60 (slide cam member 62) moves forward while the resilient member 52 is compressed. This causes the front cam 62a of the slide cam member 62 to contact the rear cam 80a of the rotating cam member 80. In this embodiment, the second surface of the front cam 62a and the second surface of the rear cam 80a come into contact with each other. When the slide cam member 62 moves further forward, the second surface of the front cam 62a slides against the second surface of the rear cam 80a, and the rotating cam member 80 rotates slightly to the other side in the circumferential direction dc (see Fig. 14).

[0080] When the slide cam member 62 moves further forward, the second surface of the front cam 62a slides against the second surface of the rear cam 80a, and the rotating cam member 80 rotates further to the other side in the circumferential direction dc. Thereafter, the rotation of the rotating cam member 80 stops in a state in which the first surface of the rear cam 80a and the first surface of the front cam 62a face to face and come into contact with each other, and the second surface of the rear cam 80a and the second surface of the front cam 62a face to face and come into contact with each other (see FIG. 15). At this time, a part of the first cam surface 84a of the rotating cam member 80 is maintained facing a part of the pressure receiving surface 24c of the locking portion 24b in the axial direction da.

[0081] When the operator releases the pressure on the first operating body 60 in this state, the elastic force of the elastic member 56 moves the holding member 90 and the rotating cam member 80 backward, and the first cam surface 84a of the rotating cam member 80 and the pressure-receiving surface 24c of the rear shaft 24 come into contact with each other again, returning to the state shown in FIG. 13. Therefore, the tip of the feeding unit 30 is maintained protruding from the front end opening 20a of the barrel 20. That is, the mechanical pencil 10 is maintained in a protruding state. In other words, even if the first operating body 60 is pressed forward in the protruding state, the tip of the feeding unit 30 does not retract from the front end opening 20a of the barrel 20. The feeding operation of the writing lead 100 in the feeding unit 30 is as described above, so a description thereof will be omitted.

[0082] Next, with reference to Fig. 13 and Fig. 16, an example of the operation of the retractable unit 50 when retracting the tip of the feeding unit 30 from the front end opening 20a of the barrel 20 will be described. In the protruding state shown in Fig. 13, at least a part of the pressing surface 74a of the second operating body 70 and at least a part of the second cam surface 86a of the rotating cam member 80 face each other in the axial direction da. Note that the entire pressing surface 74a of the second operating body 70 and the entire second cam surface 86a of the rotating cam member 80 may face each other in the axial direction da.

[0083] In this state, when the operator presses the first operating body 60 forward, the pressing surface 74a and the second cam surface 86a come into contact with each other. When the first operating body 60 moves further forward, the second cam surface 86a is pressed against the pressing surface 74a, and the rotating cam member 80 moves forward. At this time, since the rotating cam member 80 is biased backward by the elastic member 56, the second cam surface 86a slides against the pressing surface 74a, and the rotating cam member 80 rotates toward the other side in the circumferential direction dc. At this time, the first cam surface 84a of the rotating cam member 80 comes out forward from the locking portion 24b. That is, the locking of the rotating cam member 80 to the locking portion 24b is released.

[0084] When the rotation cam member 80 is released from the locking portion 24b, the second cam surface 86a slides further against the pressing surface 74a, and the rotation cam member 80 rotates further toward the other side in the circumferential direction dc. As a result, the second cam surface 86a and the pressing surface 74a do not face each other in the axial direction da, and the ridges 82 (the first ridges 84 and the second ridges 86) of the rotation cam member 80 are positioned on the extension lines of the grooves 24a of the barrel 20 (FIG. 16). Thereafter, the rotation cam member 80 moves backward by the elastic force of the elastic member 56, and the ridges 82 (the first ridges 84 and the second ridges 86) enter the grooves 24a, respectively, and return to the state (retracted state) of FIG. 10. As a result, the tip of the feeding unit 30 retracts from the front end opening 20a of the barrel 20. That is, the mechanical pencil 10 changes from the protruding state to the retracted state.

[0085] The mechanical pencil 10 of this embodiment comprises a barrel 20 having a front end opening 20a and a locking portion 24b formed on its inner surface, an advancing unit 30 that advances the writing lead 100, and a retractable unit 50 that causes the front end of the advancing unit 30 to protrude and retract from the front end opening 20a. The retractable unit 50 includes a first operating body 60, a second operating body 70, and a rotating cam member 80. When the first operating body 60 is operated, the rotating cam member 80 rotates to one side in the circumferential direction dc and is locked by the locking portion 24b, and the front end protrudes from the front end opening 20a. When the second operating body 70 is operated, the rotating cam member 80 rotates to the other side in the circumferential direction dc, the locking of the rotating cam member 80 to the locking portion 24b is released, and the front end retracts from the front end opening 20a.

[0086] According to such a mechanical pencil 10, the retractable unit 50 can be configured only by the barrel 20, the first operating body 60, the second operating body 70, and the rotating cam member 80, so that the structure of the retractable unit 50 is simplified. In addition, the number of parts of the retractable unit 50 can be reduced.

[0087] In the mechanical pencil 10 of this embodiment, the second operating body 70 includes a pressing surface 74a facing forward and extending toward the other side of the circumferential direction dc as it approaches rearward, and the rotating cam member 80 includes a first cam surface 84a facing rearward and extending toward one side of the circumferential direction dc as it approaches rearward, and a second cam surface 86a facing rearward and extending toward the other side of the circumferential direction dc as it approaches rearward, and when the front end of the pay-out unit 30 protrudes from the front end opening 20a, at least a portion of the pressing surface 74a and at least a portion of the second cam surface 86a face each other in the axial direction da.

[0088] According to such a mechanical pencil 10, the rotating cam member 80 can be rotated to the other side in the circumferential direction dc simply by pressing the second operating body 70 forward. That is, the front end of the advancing unit 30 can be retracted from the front end opening 20a of the barrel 20 with a simple operation.

[0089] In the mechanical pencil 10 of this embodiment, the rotating cam member 80 has a plurality of ridges 82 provided on the outer peripheral surface of the rotating cam member 80 and extending in the axial direction da, the plurality of ridges 82 including a first ridge 84 and a second ridge 86, the first cam surface 84a being disposed at the rear end of the first ridge 84, and the second cam surface 86a being disposed at the rear end of the second ridge 86.

[0090] According to such a mechanical pencil 10, since an additional member for providing the second cam surface 86a is not required, it is possible to suppress an increase in the number of parts. Also, since there is no need to provide an additional protrusion or the like for providing the second cam surface 86a on the rotating cam member 80, the structure of the rotating cam member 80 is simplified.

[0091] In the mechanical pencil 10 of this embodiment, the multiple protrusions 82 are arranged side by side at equal angular pitches in the circumferential direction dc.

[0092] According to such a mechanical pencil 10, the force acting on the rotating cam member 80 is prevented from being biased along the circumferential direction dc, so that the rotating cam member 80 can be operated smoothly.

[0093] In the mechanical pencil 10 of this embodiment, the locking portion 24b includes a pressure-receiving surface 24c facing forward and extending toward one side in the circumferential direction dc as it moves toward the rear, and the rotating cam member 80 is locked to the locking portion 24b when the first cam surface 84a comes into contact with the pressure-receiving surface 24c.

[0094] According to such a mechanical pencil 10, the engagement between the first cam surface 84a and the pressure-receiving surface 24c makes it possible to stably maintain the state in which the front end of the feeding unit 30 protrudes from the front end opening 20a. [Explanation of symbols]

[0095] 10. Mechanical Pencil 20 shaft cylinder 20a Front end opening 22 Front axle 24 rear axle 24a Groove 24b Locking part 24c Pressure surface 24d slit 24e Inner step 26 Grip material 28 Tip member 28a Stepped section 30 Payout unit 31 Core Pipe 33 Chuck 35 Connectors 35a Contact part 37 Elastic members 39 Supporting member 40 Pen tip parts 40a Shoulder 41 Fasteners 43 Core holder 45 Outer pipe 47 Tail plug 49 Heavy body 50 Appearing Unit 52 Elastic members 54 Supporting member 54a Receiving part 56 Elastic members 60 1st operating body 62 Slide cam member 62a Front Cam 62b protrusion 62c Inner collar 62d opening 62e Erasing member holding part 64 Shoulder 66 Erasing materials 68 Cap 70 Second operating body 72 Anti-rotation part 74 Pressing part 74a Pressing surface 80 Rotating cam member 80a Rear Cam 82 protrusion 84 First protrusion 84a First cam surface 86 Second protrusion 86a Second cam surface 90 Retaining member 92 Flange 92a Receiving part 94 Inner Rib 96 Inward protrusion 96a Opening 100 writing lead A Center axis da Axial direction dc circumferential direction

Claims

1. a barrel having a front end opening and a locking portion formed on an inner surface; A feeding unit that feeds out a writing lead; a retractable unit that causes a front end of the payout unit to protrude from and retract into the front end opening, The retractable unit includes a first operating body, a second operating body, and a rotating cam member, When the first operating body is operated, the rotating cam member rotates to one side in a circumferential direction and is engaged with the engaging portion, and the front end portion protrudes from the front end opening, When the second operating body is operated, the rotating cam member rotates to the other side in the circumferential direction, the rotating cam member is released from the locking portion, and the front end portion retracts from the front end opening.

2. the second operation body includes a pressing surface facing forward and extending toward the other side in the circumferential direction as it moves rearward, the rotating cam member includes a first cam surface facing rearward and extending toward the one side in the circumferential direction as it moves rearward, and a second cam surface facing rearward and extending toward the other side in the circumferential direction as it moves rearward, The mechanical pencil according to claim 1 , wherein when the front end of the feeding unit protrudes from the front end opening, at least a portion of the pressing surface and at least a portion of the second cam surface face each other in the axial direction.

3. the rotating cam member has a plurality of protrusions provided on an outer circumferential surface of the rotating cam member and extending in an axial direction, The plurality of ridges include a first ridge and a second ridge, the first cam surface is disposed at a rear end of the first protrusion, The mechanical pencil according to claim 2 , wherein the second cam surface is disposed at a rear end of the second ridge.

4. The mechanical pencil according to claim 3 , wherein the plurality of ridges are arranged side by side at equal angular pitches in the circumferential direction.

5. The locking portion includes a pressure receiving surface facing forward and extending toward the one side in the circumferential direction as it moves rearward, The mechanical pencil according to any one of claims 2 to 4, wherein the rotating cam member is locked to the locking portion by the first cam surface contacting the pressure receiving surface.

Images