mechanical pencil

Abstract

To properly hold a writing lead by a lead drawing unit even when a length of a lead pipe is longer than a predetermined length.SOLUTION: A mechanical pencil 10 includes: a barrel 20; an operation member 30 that includes a body portion 31 positioned within the barrel 20 and an operation portion 33 connected to the body portion 31, and is movable back and forth with respect to the barrel 20; and a lead drawing unit 40 arranged in the barrel 20 and having a lead pipe 41 for accommodating a writing lead 80, the writing lead 80 being drawn forward by pressing the operation portion 33 forward. The lead drawing unit 40 has a slide member 50 configured to be movable back and forth with respect to the barrel 20. The slide member 50 has a pressing portion 57 capable of pressing the lead pipe 41 forward. The lead pipe 41 and the pressing portion 57 are spaced apart in a front-rear direction with a gap G therebetween.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] A conventional mechanical pencil is known that has a barrel, a lead-advancing unit disposed within the barrel, and an operating member that includes a clip (see Patent Document 1). In this mechanical pencil, when the user presses the clip forward, the operating member moves forward and presses the rear end of the lead-advancing unit. This pressing force then activates the lead-advancing unit, and the writing lead is advanced forward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 7-37687 Summary of the Invention [Problem to be solved by the invention]

[0004] When using a mechanical pencil, oils and sweat from the user's hands can seep into the interior through gaps in the barrel and adhere to the lead pipe. When this happens, the oils and sweat seep into the lead pipe, causing it to expand and stretch in the front-to-back direction. Furthermore, writing leads contain oils such as silicone oil, and when a writing lead is placed inside the lead pipe, the oils from the writing lead can adhere to the lead pipe. In this case, too, the oils seep into the lead pipe, causing it to stretch.

[0005] Core pipes are usually manufactured by cutting a long pipe-shaped member to a predetermined length. At this time, the length of the core pipe may vary. That is, core pipes that are shorter or longer than the predetermined dimension may be manufactured.

[0006] In conventional mechanical pencils, the operating member is directly connected to the rear end of the lead pipe that houses the lead. If the lead pipe becomes longer than the specified length due to oil or sweat seeping in or manufacturing variations, and is directly connected to the operating member, the chuck connected to the front end of the lead pipe will be positioned further forward than the specified position. In other words, the chuck will always be pressed forward. This causes the front end of the chuck to always be open, which could result in the lead not being properly held by the lead-dispensing unit.

[0007] The present invention has been made in consideration of these points, and aims to properly hold the writing lead using the lead feed unit even when the length of the lead pipe is longer than a predetermined length. [Means for solving the problem]

[0008] The mechanical pencil according to the present invention comprises: A shaft cylinder and an operating member including a main body portion located within the barrel and an operating portion connected to the main body portion, the operating member being movable back and forth relative to the barrel; a lead dispenser unit disposed in the barrel and having a lead pipe for accommodating a writing lead; A mechanical pencil in which the writing lead is advanced forward by pressing the operating portion forward, The core feeding unit has a slide member configured to be movable back and forth relative to the barrel, the slide member has a pressing portion that can press the core pipe forward, The core pipe and the pressing portion are spaced apart in the front-rear direction via a gap.

[0009] In the mechanical pencil according to the present invention, The main body may have a space into which the writing lead can enter after moving rearward from the rear end of the lead pipe.

[0010] In the mechanical pencil according to the present invention, The barrel includes a front axle and a rear axle detachably attached to the front axle, The slide member may be attached to the front axle.

[0011] In the mechanical pencil according to the present invention, The operating member may be attached to the rear axle.

[0012] In the mechanical pencil according to the present invention, a rear end member attached to a rear end of the barrel; The rear end member may be made of a conductive material.

[0013] In the mechanical pencil according to the present invention, The barrel may have a conductive portion that contacts the rear end member. [Effects of the Invention]

[0014] According to the present invention, even if the length of the lead pipe is longer than a predetermined length, the lead can be properly held by the lead feed unit. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the appearance of a mechanical pencil according to the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view showing a mechanical pencil. [Figure 3] FIG. 3 is a vertical cross-sectional view showing the front part of the mechanical pencil separated into front and rear parts. [Figure 4] FIG. 4 is a vertical cross-sectional view showing the rear portion of the mechanical pencil separated into front and rear halves. [Figure 5] FIG. 5 is a vertical cross-sectional view for explaining a space provided in an operating member of the mechanical pencil. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the present invention will be described below with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios of the actual objects have been appropriately changed and exaggerated for the sake of ease of illustration and understanding.

[0017] Furthermore, terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "identical," as well as values ​​of lengths and angles, are not to be construed as being bound by strict meanings, but rather as including a range within which similar functions can be expected.

[0018] In this specification, the direction in which the central axis A of the mechanical pencil extends (longitudinal direction, vertical direction in a longitudinal cross section) is referred to as the axial direction da, the direction perpendicular to the axial direction da is referred to as the radial direction dr, and the direction along the circumference around the central axis A is referred to as the circumferential direction. In addition, along the axial direction da, the side that comes close to a writing surface such as a paper surface when writing is referred to as the front, and the side that moves away from the writing surface is referred to as the rear.

[0019] Fig. 1 is a diagram showing the appearance of a mechanical pencil 10 according to the present invention, and Fig. 2 is a vertical cross-sectional view showing the mechanical pencil 10. The mechanical pencil 10 comprises a barrel 20, an operating member 30, and a lead feeding unit 40.

[0020] 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. At least a part of the lead feeding unit 40 is disposed inside the barrel 20. The barrel 20 has a front shaft 21, a rear shaft 25 connected to the rear end of the front shaft 21, a tip member 28 connected to the front end of the front shaft 21, and a sleeve 29 attached to the front end of the tip member 28.

[0021] Front shaft 21 is a member having a generally cylindrical shape and is intended to be grasped with the fingers when a user writes with mechanical pencil 10. A slit 22 is formed in the rear end of front shaft 21 to engage with an engaging protrusion 51 of slide member 50, which will be described later. Slit 22 is a through-hole that penetrates the wall of front shaft 21 in the radial direction dr. However, this is not limited thereto, and slit 22 may also be a groove provided on the inner surface of front shaft 21. Slit 22 extends in the axial direction da. A first receiving portion 23 that receives the elastic force of elastic member 47, which will be described later, is formed on the inner surface of front shaft 21. First receiving portion 23 is the rear-facing surface of a step formed on the inner surface of front shaft 21.

[0022] The rear axle 25 is a member disposed rearward of the front axle 21 and having a generally cylindrical shape. The front end of the rear axle 25 is attached to the rear end of the front axle 21, thereby allowing the rear axle 25 to be detachably attached to the front axle 21. As an example, the rear axle 25 is detachably attached to the front axle 21 by threading a male thread formed on the outer periphery of the rear end of the front axle 21 with a female thread formed on the inner periphery of the front end of the rear axle 25. A slit 26 is formed in the side surface of the rear axle 25, allowing a portion of the operating member 30 to pass through. The slit 26 is a through-hole that penetrates the wall of the rear axle 25 in the radial direction dr. The slit 26 extends in the axial direction da. As a portion of the operating member 30 moves along the slit 26, the operating member 30 can move back and forth along the axial direction da relative to the axle tube 20 (rear axle 25).

[0023] Tip member 28 is a member that forms the tip portion of mechanical pencil 10. Tip member 28 has a generally conical shape, and its outer diameter decreases toward the front. The rear end of tip member 28 is attached to the front end of front shaft 21, thereby connecting tip member 28 to front shaft 21. As an example, tip member 28 is connected to front shaft 21 by threading a female thread formed on the inner periphery of the rear end of tip member 28 into a male thread formed on the outer periphery of the front end of front shaft 21.

[0024] The sleeve 29 is a member that holds the front end of the writing lead 80. The writing lead 80, advanced forward by the lead feeding unit 40, passes through the sleeve 29 and protrudes from the front end of the sleeve 29. The sleeve 29 is fixed to the lead holder 46, which will be described later, and moves back and forth relative to the tip member 28 together with the lead holder 46. When the front end of the writing lead 80 wears, the sleeve 29 abuts against the writing surface, such as paper, and retracts relative to the tip member 28. This allows the front end of the writing lead 80 to protrude a certain length from the front end of the sleeve 29. However, this is not limited to this, and the sleeve 29 may also be fixed to the tip member 28.

[0025] A rear end member 12 is attached to the rear end of the rear axle 25. In the example shown in FIG. 2 , an inward protrusion is formed on the inner surface of the front end of the rear end member 12, and this inward protrusion fits into a recess formed in the outer surface of the rear end of the rear axle 25. This restricts forward and backward movement of the rear end member 12 relative to the rear axle 25. A crown 14 is attached to the radially outer side of the rear end of the rear axle 25. The crown 14 has the function of fixing the rear end member 12 to the rear axle 25. In particular, the crown 14 holds the front end of the rear end member 12 so that the inward protrusion of the rear end member 12 does not slip out of the recess of the rear axle 25. As an example, the crown 14 is connected to the rear axle 25 by threading a female thread formed on the inner periphery of the front end of the crown 14 into a male thread formed on the outer periphery of the rear end of the rear axle 25.

[0026] The rear end member 12 may be a member for adding additional functions to the mechanical pencil 10. For example, the rear end member 12 may be the pen tip of a touch pen capable of operating a touch panel. In this case, the rear end member 12 is preferably made of a conductive material. Examples of conductive materials that can be used include metal, conductive resin, and conductive elastic body. From the viewpoint of preventing scratches on the touch panel and preventing impact noises from being generated when touching the touch panel, the rear end member 12 is more preferably made of a conductive resin or a conductive elastic body. Even more preferably, the rear end member 12 is made of a conductive elastic body. Examples of conductive elastic bodies that can be used include conductive rubber and conductive elastomer.

[0027] When rear end member 12 is the pen tip of a touch pen, barrel 20 preferably has a conductive portion 27 that contacts rear end member 12. In the example shown in FIGS. 1 and 2, rear barrel 25 that contacts rear end member 12 is made of a conductive material. In this case, the entire rear barrel 25 is the conductive portion 27. This is not limiting, and conductive portion 27 may be provided on only a portion of rear barrel 25. Furthermore, front barrel 21 may have conductive portion 27 in addition to rear barrel 25. Examples of conductive materials that can be used to make up conductive portion 27 include metal, conductive resin, and conductive elastic body.

[0028] The rear end member 12 may be an erasing member for making handwriting invisible. Examples of the erasing member include an eraser, a friction member for discoloring or erasing thermochromic handwriting, etc. Alternatively, the erasing member may be a mechanism for applying a tape member, known as correction tape, over handwriting to cover it and make it invisible.

[0029] The operating member 30 is a member operated by the user to advance the writing lead 80. When the operating member 30 moves forward, the lead advancement unit 40 is activated, advancing the writing lead 80 forward. The operating member 30 includes a main body 31 located within the barrel 20 (rear barrel 25) and an operating unit 33 connected to the main body 31. The main body 31 refers to the portion of the operating member 30 located within the barrel 20. The main body 31 can move back and forth within the barrel 20 along the axial direction da. The operating unit 33 protrudes outward from the outer surface of the barrel 20 (rear barrel 25) along the radial direction dr and is intended to be directly operated by the user's finger. In this embodiment, the operating unit 33 is a clip. When the user presses the clip forward, the entire clip moves forward relative to the barrel 20. The operating unit 33 is not limited to a clip and may be another protruding portion operable by the user's finger. The operating part 33 is connected to the main body 31 via a connecting part 34. The connecting part 34 is located within the slit 26 of the rear axle 25, and is capable of moving back and forth in the axial direction da along the slit 26. This allows the entire operating member 30 to move back and forth relative to the barrel 20 (rear axle 25).

[0030] In the mechanical pencil 10 of this embodiment, when the user presses the operating portion 33 forward, the lead feed unit 40 is activated and the writing lead 80 is advanced forward. In this case, the rear end member 12 can be fixed to the barrel 20. In this case, when the mechanical pencil 10 is turned over and the rear end member 12 is used, the rear end member 12 does not move relative to the barrel 20. For example, if the rear end member 12 is the tip of a touch pen, when the rear end member 12 is brought into contact with a touch panel, the rear end member 12 does not retract into the barrel 20, facilitating touch operations using the rear end member 12. Furthermore, because the user rarely touches the rear end member 12 with their fingers or the like, soiling of the rear end member 12 can be prevented. The same applies when the rear end member 12 is an eraser.

[0031] FIG. 3 is a longitudinal cross-sectional view showing the front side (front shaft 21 side) of the mechanical pencil 10 separated into front and rear halves, and FIG. 4 is a longitudinal cross-sectional view showing the rear side (rear shaft 25 side) of the mechanical pencil 10 separated into front and rear halves. In this embodiment, the rear shaft 25 is detachably attached to the front shaft 21. When refilling the mechanical pencil 10 with a writing lead 80, the rear shaft 25 is removed from the front shaft 21, and the writing lead 80 is inserted into the lead pipe 41 attached to the front shaft 21. The operating member 30 is attached to the rear shaft 25. Therefore, when the rear shaft 25 is removed from the front shaft 21, the operating member 30 is removed from the front shaft 21 together with the rear shaft 25. In this case, when refilling the writing lead 80, the writing lead 80 to be refilled does not interfere with the operating member 30, making it easy to refill the writing lead 80.

[0032] The operating member 30 of this embodiment includes a first component 35 and a second component 39. The entire first component 35 and a portion of the second component 39 constitute the main body 31. Furthermore, portions of the second component 39 constitute the operating portion 33 and the connecting portion 34. The first component 35 and the second component 39 are fixed to each other and operate integrally. The first component 35 is inserted rearward into the rear axle 25 from an opening at the front end of the rear axle 25. A portion of the second component 39 passes through the slit 26 of the rear axle 25 and is inserted radially inward into the rear axle 25. The first component 35 and the second component 39 are then coupled together within the rear axle 25. The first component 35 and the second component 39 are coupled together by fitting together, for example, by fitting a convex portion on one of the first component 35 and the second component 39 into a concave portion on the other component. In this way, since the operating member 30 includes a first part 35 and a second part 39 that are fixed to each other, the operating member 30 will not come off the barrel 20 during use, and stable core ejection operation can be performed.

[0033] The main body 31 has a first abutment portion 37 that abuts against the slide member 50. In the example shown in FIGS. 2 and 4, the first abutment portion 37 is provided at the front end of the main body 31. In the example shown, the first abutment portion 37 is provided at the front end of the first component 35. When the user presses the operating unit 33 forward, the pressing force is transmitted from the operating member 30 to the slide member 50 via the first abutment portion 37 and a second abutment portion 52 of the slide member 50, which will be described later.

[0034] The main body 31 has a space S. As shown in FIG. 5 , the space S is configured to allow the writing lead 81 that has moved rearward from the rear end 41a of the lead pipe 41 to enter. The space S is open at the front end of the main body 31 and extends rearward from the front end of the main body 31. With the mechanical pencil 10, after writing is finished or when the front end of the writing lead 80 significantly protrudes from the front end of the mechanical pencil 10 (sleeve 29), the operating member 30 may be operated to retract the front end of the writing lead 80 that protrudes from the front end of the mechanical pencil 10 into the mechanical pencil 10. Furthermore, when refilling the writing lead 80, the writing lead 80 may be inserted into the mechanical pencil 10 from the front end of the mechanical pencil 10. When a writing lead 80 used in writing is retracted while another writing lead 81 is stored in the lead pipe 41, the front end of the writing lead 81 may be pushed by the rear end of the writing lead 80, causing the writing lead 81 to move rearward. At this time, the rear end of the lead 81 moves rearward beyond the rear end 41a of the lead pipe 41. If the operating member 30 located behind the lead pipe 41 prevents the lead 81 from moving rearward, the lead 80 cannot be stored in the mechanical pencil 10. If the user tries to store the lead 80 with too much force, the lead 80 or the lead 81 may break.

[0035] In this embodiment, because the main body 31 of the operating member 30 has the space S, even if the rear end of another writing lead 81 is pushed by the writing lead 80 and moves rearward beyond the rear end 41a of the lead pipe 41, the main body 31 does not prevent the writing lead 81 from moving rearward. Therefore, the writing lead 80 can be smoothly stored inside the mechanical pencil 10. It is also possible to effectively prevent breakage of the writing lead 80 or the writing lead 81. Considering that many commercially available writing leads 80 are 60 mm long, it is preferable that the length from the front end of the mechanical pencil 10 (sleeve 29) to the rear end of the space S along the axial direction da be at least twice the length of the writing lead 80, i.e., 120 mm or more.

[0036] The lead dispensing unit 40 has a mechanism that advances the writing lead 80 forward when the user operates the operating member 30. The lead dispensing unit 40 of this embodiment includes a lead pipe 41, a chuck 42, a resilient member 43, a receiving member 44, a fastener 45, a lead holder 46, a resilient member 47, and a slide member 50.

[0037] The lead pipe 41 is a member that houses the writing lead 80. The lead pipe 41 has an overall cylindrical (pipe-like) shape. The lead pipe 41 also has the function of transmitting the pressing force received from the slide member 50 to the chuck 42. The lead pipe 41 is made of, for example, resin.

[0038] The chuck 42 is a member that grips the writing lead 80. The chuck 42 can move in the front-to-rear direction together with the lead pipe 41. In the example shown in Figures 2 and 3, the rear end of the chuck 42 is inserted into the front end of the lead pipe 41, thereby fixing the chuck 42 to the lead pipe 41.

[0039] A resilient member 43 is disposed in front of the core pipe 41. The resilient member 43 is, for example, a coil spring. A receiving member 44 is disposed in front of the resilient member 43, and the resilient member 43 is disposed in a compressed state between the front end of the core pipe 41 and the receiving member 44. The receiving member 44 is a member that receives the resilient force of the resilient member 43 and is pressed forward by the resilient force of the resilient member 43, abutting against a step formed on the inner surface of the tip member 28. In the example shown in FIGS. 2 and 3 , the front end of the core pipe 41 is inserted into the receiving member 44 from the rear. This prevents the front end of the core pipe 41 and the receiving member 44 from shifting in the radial direction dr. The fastener 45 is an annular part located radially outward from the front portion of the chuck 42. The rear end of the fastener 45 abuts against the receiving member 44, thereby restricting rearward movement of the fastener 45. The lead holder 46 is disposed in front of the chuck 42 and is a member that abuts against the outer surface of the writing lead 80 to hold the writing lead 80. The lead holder 46 is formed from an elastic member such as resin or rubber, and prevents the writing lead 80 from moving in the axial direction da when the chuck 42 is not gripping the writing lead 80. In this embodiment, the lead holder 46 is configured to be movable back and forth within a predetermined range relative to the tip member 28.

[0040] The slide member 50 has a function of transmitting the pressing force from the operating member 30 to the core pipe 41. The slide member 50 is disposed radially outward of the core pipe 41 in the radial direction dr and has a generally cylindrical shape. An engaging protrusion 51 is provided on the outer surface of the slide member 50. The engaging protrusion 51 engages with the slit 22 of the front axle 21. The engaging protrusion 51 is located within the slit 22 and is movable along the axial direction da along the slit 22. This allows the slide member 50 to move back and forth relative to the barrel 20 (front axle 21). The movement range of the engaging protrusion 51 in the axial direction da is restricted by the slit 22. The slide member 50 has a second abutment portion 52 that abuts against the first abutment portion 37 of the operating member 30. In the example shown in FIGS. 2 and 3, the second abutment portion 52 is provided at the rear end of the slide member 50.

[0041] A resilient member 47 is disposed between the front end of the slide member 50 and the first receiving portion 23 of the front axle 21. The resilient member 47 is, for example, a coil spring. The slide member 50 has a second receiving portion 53 that receives the resilient force of the resilient member 47. In the example shown in FIGS. 2 and 3 , the second receiving portion 53 is provided at the front end of the slide member 50. The resilient member 47 is disposed in a compressed state between the first receiving portion 23 of the front axle 21 and the second receiving portion 53 of the slide member 50. The slide member 50 is pressed rearward by the resilient force of the resilient member 47. This pressing force is transmitted from the slide member 50 to the operating member 30 via the second abutment portion 52 and the first abutment portion 37 of the operating member 30. As a result, when no forward pressing force is acting on the operating portion 33, the resilient force of the resilient member 47 positions the operating member 30 at the rearmost position of its movable range in the axial direction da.

[0042] Slide member 50 is attached to front axle 21. Therefore, when rear axle 25 is removed from front axle 21, slide member 50 is separated from operating member 30, as shown in Figure 3. Because slide member 50 is pressed rearward by the resilient force of resilient member 47, when rear axle 25 is removed from front axle 21, engaging protrusion 51 abuts against the rear end of slit 22 of front axle 21.

[0043] A through-hole 54 extending in the axial direction da is formed in the rear end of the slide member 50. In the example shown in FIGS. 2 and 3, a protrusion 55 that protrudes inward is formed on the inner surface of the rear end of the slide member 50, and the through-hole 54 is the portion surrounded by this protrusion 55. The through-hole 54 has a shape and dimensions that allow the writing lead 80 to pass through. When refilling the writing lead 80, with the rear barrel 25 removed from the front barrel 21, the writing lead 80 is inserted into the lead pipe 41 via the through-hole 54.

[0044] A guide surface 56 is formed at the rear end of the slide member 50 to guide the front end of the writing lead 80 when refilling the writing lead 80. The guide surface 56 extends in a direction inclined with respect to both the axial direction da and the radial direction dr, moving away from the central axis A along the radial direction dr as it extends rearward along the axial direction da. Therefore, the guide surface 56 has a so-called funnel-like shape as a whole. In the example shown in FIGS. 2 and 3 , the guide surface 56 is provided on the protruding portion 55. When refilling the writing lead 80, if the writing lead 80 is moved forward with its front end in contact with the guide surface 56, the front end of the writing lead 80 is guided by the guide surface 56 toward the through-hole 54. This allows the writing lead 80 to be easily inserted into the lead pipe 41.

[0045] The slide member 50 has a pressing portion 57 that can press the core pipe 41 forward. In the example shown in FIGS. 2 and 3, the pressing portion 57 is configured to be able to press the rear end 41a of the core pipe 41 forward. In the example shown, the pressing portion 57 is a front-facing surface of the protruding portion 55. When the rear axle 25 is assembled to the front axle 21 and no forward pressing force is acting on the operating member 30, the core pipe 41 and the pressing portion 57 are spaced apart in the front-to-rear direction by a gap G. In particular, when the rear axle 25 is assembled to the front axle 21 and no forward pressing force is acting on the operating member 30, the rear end 41a of the core pipe 41 and the pressing portion 57 are spaced apart in the front-to-rear direction by a gap G.

[0046] The lead pipe 41 may expand and become longer due to the penetration of oils and sweat from the user's hands that have entered the interior through gaps in the barrel 20. The lead pipe 41 may also expand due to the penetration of oils such as silicone oil contained in the writing lead 80 housed inside the lead pipe 41. Furthermore, when the lead pipe 41 is manufactured by cutting a long pipe-shaped member to a predetermined length, variations in the length of the lead pipe 41 occur, and the length of the lead pipe 41 may become longer than the predetermined length.

[0047] If the operating member is directly connected to the rear end of the lead pipe, the chuck connected to the front end of the lead pipe will be positioned further forward than the specified position. This means that the chuck will always be pressed forward. This will cause the front end of the chuck to always be open, which could prevent the lead from being properly held by the lead dispenser.

[0048] In the mechanical pencil 10 of this embodiment, the lead pipe 41 and the pressing portion 57 are separated in the front-to-rear direction by a gap G, so that even if the length of the lead pipe 41 is greater than a predetermined length, the gap G can absorb changes in the length of the lead pipe 41. This prevents the chuck 42 from being constantly pressed forward, even if the length of the lead pipe 41 is greater than a predetermined length. This allows the chuck 42 to properly hold the writing lead 80.

[0049] The distance between the rear end 41a of the core pipe 41 and the pressing portion 57, i.e., the dimension of the gap G along the axial direction da, is preferably 1 mm or more and 3 mm or less when the rear shaft 25 is attached to the front shaft 21 and no forward pressing force is acting on the operating member 30. By making the dimension of the gap G along the axial direction da 1 mm or more, the gap G can sufficiently absorb changes in the length of the core pipe 41. Furthermore, by making the dimension of the gap G along the axial direction da 3 mm or less, it is possible to prevent the core feeding unit 40 from becoming large.

[0050] Next, the operation of the mechanical pencil 10 of this embodiment will be described. FIG. 2 shows the mechanical pencil 10 of this embodiment in a state where no forward pressing force is acting on the operating member 30. In this state, the resilient force of the resilient member 47 presses the slide member 50 against the operating member 30, and the operating member 30 is positioned at the rearmost position within its movable range in the axial direction da. At this time, a pressing force due to the resilient force of the resilient member 47 acts between the first contact portion 37 of the operating member 30 and the second contact portion 52 of the slide member 50. The core pipe 41 and the pressing portion 57 of the slide member 50 are spaced apart in the front-rear direction via a gap G. In particular, the rear end 41a of the core pipe 41 and the pressing portion 57 are spaced apart in the front-rear direction via a gap G.

[0051] When the user presses the operating portion 33 forward, the operating member 30 and the sliding member 50 move forward against the elastic force of the elastic member 47. At this time, the core pipe 41 does not move. Therefore, as the operating member 30 and the sliding member 50 move forward, the dimension of the gap G along the axial direction da decreases. Then, the pressing portion 57 of the sliding member 50 abuts against the rear end 41a of the core pipe 41.

[0052] When the user presses the operating portion 33 further forward, the elastic member 43 is compressed, and the core pipe 41 and chuck 42 move forward together with the operating member 30 and the slide member 50 against the elastic forces of the elastic member 43 and the elastic member 47. When the chuck 42 is not pressed forward, the outer surface of the front portion of the chuck 42 abuts against the fastener 45 from the inside. This prevents the front portion of the chuck 42 from opening radially outward. This allows the front portion of the chuck 42 to grip the writing lead 80. When the chuck 42 moves forward together with the fastener 45, the writing lead 80 gripped by the chuck 42 moves forward. When the chuck 42 moves further forward, the fastener 45 abuts against the inner step of the tip member 28, and the front portion of the chuck 42 moves forward relative to the fastener 45. This causes the front portion of the chuck 42 to open outward, releasing the writing lead 80 that was held in the front portion of the chuck 42. At this time, the writing lead 80 is held by the lead holder 46.

[0053] When the user releases pressure on the operating part 33, the operating member 30, slide member 50, lead pipe 41, and chuck 42 move rearward due to the resilient forces of the resilient members 43 and 47. This causes the front portion of the chuck 42 to move toward the inside of the fastener 45, abutting against the fastener 45 and gripping the writing lead 80. At this time, the writing lead 80 is held by the lead holder 46, so the writing lead 80 is prevented from moving rearward.

[0054] The fastening force of the fastener 45 stops the rearward movement of the chuck 42 and the core pipe 41 fixed to the chuck 42. Thereafter, the elastic force of the elastic member 47 causes the operating member 30 and the sliding member 50 to move rearward. This causes the pressing portion 57 of the sliding member 50 to move away from the rear end 41a of the core pipe 41, forming a gap G between the pressing portion 57 and the rear end 41a. As the operating member 30 and the sliding member 50 move rearward, the dimension of the gap G along the axial direction da increases. Then, the operating member 30 reaches the rearmost position of its movable range in the axial direction da, and the rearward movement of the operating member 30 and the sliding member 50 stops. In the example shown in FIG. 2 , the connecting portion 34 of the operating member 30 abuts against the front end of the crown 14, stopping the rearward movement of the operating member 30.

[0055] By repeating the above steps, the writing lead 80 is advanced forward, and the front end of the writing lead 80 passes through the sleeve 29 and protrudes forward from the front end of the sleeve 29 .

[0056] After finishing writing or when the front end of the writing lead 80 protrudes significantly from the front end of the mechanical pencil 10 (sleeve 29), the operating member 30 may be operated to retract the front end of the writing lead 80 protruding from the front end of the mechanical pencil 10 into the mechanical pencil 10. Also, when refilling the writing lead 80, the writing lead 80 may be inserted into the mechanical pencil 10 from the front end of the mechanical pencil 10. If another writing lead 81 is located behind the writing lead 80 held by the chuck 42, the front end of the writing lead 81 is pushed by the rear end of the writing lead 80, causing the writing lead 81 to move rearward, and the rear end of the writing lead 81 is positioned rearward of the rear end 41a of the lead pipe 41.

[0057] The rear end of the lead 81, which has moved rearward from the rear end 41a of the lead pipe 41, enters the space S of the main body 31 of the operating member 30. Therefore, the main body 31 does not impede the rearward movement of the lead 81. This allows the lead 80 to be smoothly stored inside the mechanical pencil 10. It also makes it possible to effectively prevent the lead 80 or the lead 81 from breaking.

[0058] The mechanical pencil 10 of this embodiment includes a barrel 20, a main body 31 located within the barrel 20, and an operating part 33 connected to the main body 31, and is equipped with an operating member 30 that is movable back and forth relative to the barrel 20, and a lead dispensing unit 40 that is arranged within the barrel 20 and has a lead pipe 41 that houses a writing lead 80, and the mechanical pencil 10 is configured so that the writing lead 80 is advanced forward when the operating part 33 is pressed forward, and the lead dispensing unit 40 has a sliding member 50 that is configured to be movable back and forth relative to the barrel 20, and the sliding member 50 has a pressing part 57 that can press the lead pipe 41 forward, and the lead pipe 41 and the pressing part 57 are separated in the front-to-back direction by a gap G.

[0059] If the operating member is directly connected to the rear end of the lead pipe, the chuck connected to the front end of the lead pipe will be positioned further forward than the specified position. This means that the chuck will always be pressed forward. This will cause the front end of the chuck to always be open, which could prevent the lead from being properly held by the lead dispenser.

[0060] According to the mechanical pencil 10 of this embodiment, the lead pipe 41 and the pressing portion 57 are separated in the front-to-rear direction by a gap G, so that the gap G can absorb changes in the length of the lead pipe 41, even if the length of the lead pipe 41 is greater than a predetermined length. This prevents the chuck 42 from being constantly pressed forward, even if the length of the lead pipe 41 is greater than a predetermined length. This allows the chuck 42 to properly hold the writing lead 80.

[0061] In the mechanical pencil 10 of this embodiment, the main body 31 has a space S into which the writing lead 80 that has moved rearward from the rear end of the lead pipe 41 can enter.

[0062] With this mechanical pencil 10, when the front end of a writing lead 80 protruding from the front end of the mechanical pencil 10 is stored within the mechanical pencil 10, or when the writing lead 80 is refilled into the mechanical pencil 10 from the front end of the mechanical pencil 10, even if the rear end of another writing lead 81 in the lead pipe 41 is pushed by the writing lead 80 and moves rearward from the rear end 41a of the lead pipe 41, the main body 31 does not prevent the writing lead 81 from moving rearward. Therefore, the writing lead 80 can be stored smoothly within the mechanical pencil 10. It is also possible to effectively prevent the writing lead 80 or writing lead 81 from breaking.

[0063] In the mechanical pencil 10 of this embodiment, the barrel 20 includes a front shaft 21 and a rear shaft 25 detachably attached to the front shaft 21, and the slide member 50 is attached to the front shaft 21.

[0064] In the mechanical pencil 10 of this embodiment, the operating member 30 is attached to the rear shaft 25.

[0065] With this mechanical pencil 10, when refilling the mechanical pencil 10 with the writing lead 80, the rear shaft 25 can be removed from the front shaft 21, and the writing lead 80 can be inserted into the lead pipe 41 attached to the front shaft 21. Furthermore, when the rear shaft 25 is removed from the front shaft 21, the operating member 30 is removed from the front shaft 21 together with the rear shaft 25. Therefore, when refilling the writing lead 80, the writing lead 80 to be refilled does not interfere with the operating member 30, so the writing lead 80 can be easily refilled.

[0066] The mechanical pencil 10 of this embodiment has a rear end member 12 attached to the rear end of the barrel 20, and the rear end member 12 is made of a conductive material.

[0067] In the mechanical pencil 10 of this embodiment, the barrel 20 has a conductive portion 27 that comes into contact with the rear end member 12.

[0068] According to this embodiment, the mechanical pencil 10 can function as a touch pen that can operate a touch panel. This eliminates the need to carry a touch pen separately from the mechanical pencil 10. This improves the convenience of the mechanical pencil 10. [Explanation of symbols]

[0069] 10 Mechanical Pencil 12 Rear end member 14 Crown 20 shaft cylinder 21 Front axle 22 Slit 23 First Receiving Section 25 rear axle 26 Slit 27 Conductive part 28 Tip member 29 Sleeve 30 Operating member 31 Main body 33 Operation section 34 Connection 35 First Part 37 1st contact part 39 Second Part 40 Core feed unit 41 Core pipe 41a rear end 42 Zipper 43 Elastic members 44 Receiving member 45 Fasteners 46 Lead holder 47 Elastic members 50 Slide member 51 Engagement protrusion 52 Second contact part 53 Second Receiving Section 54 Through hole 55 Protrusion 56 Guide surface 57 Pressing part 80 writing lead 81 Writing lead A Center axis G Gap S space da axial direction dr radial direction

Claims

1. A cylinder including a front axle and a rear axle detachably attached to the front axle; an operating member including a main body portion located within the barrel and an operating portion connected to the main body portion, the operating member being movable back and forth relative to the barrel; a lead dispenser unit disposed in the barrel and having a lead pipe for accommodating a writing lead; A mechanical pencil in which the writing lead is advanced forward by pressing the operating portion forward, The lead feeding unit has a slide member attached to the front shaft and configured to be movable back and forth relative to the shaft tube, the slide member has a pressing portion that can press the core pipe forward, The core pipe and the pressing portion are spaced apart in the front-rear direction via a gap.

2. The mechanical pencil according to claim 1 , wherein the main body portion has a space into which the writing lead can enter after moving rearward from the rear end of the lead pipe.

3. The mechanical pencil according to claim 1 or 2, wherein the operating member is attached to the rear shaft.

4. a rear end member attached to a rear end of the barrel; The mechanical pencil according to any one of claims 1 to 3, wherein the rear end member is made of a conductive material.

5. The mechanical pencil according to claim 4 , wherein the barrel has a conductive portion that contacts the rear end member.

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