Knock-type writing implement

Abstract

[Problem] To provide a knock-type writing instrument capable of easily and reliably attaching an operating body detached from a feeding mechanism of a writing body to the feeding mechanism. [Solution] The knock-type writing instrument is provided with: a shaft cylinder (2); a writing body (8) accommodated inside the shaft cylinder (2); a feeding mechanism (3) feeding the writing body (8) forward; and an operating body (4) arranged at the rear of the feeding mechanism (3). The knock-type writing instrument has a handwriting transforming member (5) attached in front of the operating body (4) and used to remove, thermally discolor, or hide handwriting written by means of the writing body (8). The operating body (4) at least partially protrudes from the shaft cylinder (2), and is attached to be slidable back and forth and detachable with respect to the shaft cylinder (2) by a magnetic force acting between the shaft cylinder (2) and the operating body (4).

Description

[Technical Field]

[0001] The present invention relates to an operating body mounting structure for a knock-type writing instrument. [Background technology]

[0002] BACKGROUND ART Writing implements have been known that can change handwriting by rubbing handwriting written with a writing implement equipped with a writing body with a handwriting change member housed within the writing implement, thereby removing the handwriting from the writing surface or thermally changing the color from colored to colored or from colorless.

[0003] As an example of the above-mentioned writing implement, JP2011-230357A discloses a knock-type mechanical pencil in which an eraser that acts as a handwriting changer can be exposed by removing a cap that is detachably attached to the rear end opening of the barrel, and the handwriting written with the lead can be removed from the writing surface by rubbing the eraser against the handwriting.

[0004] According to the knock-type mechanical pencil of JP2011-230357A, a cylindrical cap protrudes from the rear end opening of the barrel, and an eraser is provided inside the cap. By knocking the cap, which serves as the operating body, a lead feed mechanism possessed by the barrel is operated, and the lead is fed out from the writing tip located at the front of the barrel. By removing the cap attached to the rear of the lead feed mechanism, the eraser is exposed, and handwriting made with the mechanical pencil can be removed by rubbing the eraser over the handwriting.

[0005] However, in the knock-type mechanical pencil of JP2011-230357A, the cap is detachably attached to the lead-advancing mechanism by press-fitting or locking so that the cap does not come off the lead-advancing mechanism when writing or carrying it. Therefore, when attaching the cap to the lead-advancing mechanism, the lead-advancing mechanism is pressed forward, and there is a risk that the lead will be unintentionally advanced forward. Furthermore, if the attachment of the cap to the lead-advancing mechanism stops midway and is not attached securely, the cap may come off when writing or carrying it, causing the cap to be damaged or lost and the exposed eraser to become dirty. Summary of the Invention

[0006] The present invention was made based on the above background, and its purpose is to provide a knock-type writing instrument that allows the operating body, which has been removed from the barrel, to be easily and reliably reattached without causing any problems in the extension mechanism.

[0007] [1] The knock-type writing instrument of this embodiment comprises a barrel, a writing body housed inside the barrel and having a writing part at its tip, a feeding mechanism that feeds the writing body forward, and an operating body that is disposed behind the feeding mechanism and operates the feeding mechanism. a handwriting changing member that is fastened to the front of the operating body and that removes, thermally discolors, or conceals handwriting written with the writing tool; The operating body is a knock-type writing instrument characterized in that at least a portion of it protrudes from the barrel and is detachably attached to the barrel so that it can slide back and forth relative to the barrel by magnetic force acting between the barrel and the operating body.

[0008] [2] The knock-type writing instrument of this embodiment is the knock-type writing instrument described in [1], characterized in that it has a magnet on either the barrel or the operating body, and a ferromagnetic body on the other that is magnetically attracted by the magnetic force of the magnet.

[0009] [3] The knock-type writing instrument of this embodiment is a knock-type writing instrument described in [2], characterized in that the operation body is operated to activate the dispensing mechanism, and when the distance between the magnet and the ferromagnetic body is maximized, the operation body returns to its position before operation solely by the magnetic force acting between the magnet and the ferromagnetic body.

[0010] [4] The knock-type writing instrument of this embodiment is a knock-type writing instrument described in any one of [1] to [3], characterized in that when the operating body is removed from the barrel, it can be attached and detached freely to the barrel by magnetic force even if the front and rear directions of the operating body are reversed.

[0011] [5] The knock-type writing instrument of this embodiment is a knock-type writing instrument as described in [4], characterized in that when the operating body is attached to the barrel with the front and back reversed, the operating body abuts against a regulating portion that regulates the forward movement of the operating body. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a vertical end view of a knock-type writing instrument according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged end view showing the AA end face of FIG. [Figure 3] 2 is an exploded view showing the knock-type writing instrument of FIG. 1 in an exploded state for explaining the relationship between the operating body and each part fixed to the operating body. FIG. [Figure 4] 2 is a vertical cross-sectional view showing a state in which the chuck has advanced by operating the operating body in the knock-type writing instrument of FIG. 1. FIG. [Figure 5] 2 is an explanatory diagram showing a state in which the operating body is removed from the knock-type writing instrument of FIG. 1.

[0023] FIG. [Figure 6] 6 is a vertical end view showing a state in which the operating body has been reattached to the barrel cylinder with its front and rear direction reversed from the state shown in FIG. 5. FIG. [Figure 7] FIG. 10 is a vertical end view of a shake-type mechanical pencil according to a second embodiment of the present invention. [Figure 8] FIG. 8 is an enlarged end view showing the BB end face of FIG. 7. [Figure 9]FIG. 8 is an exploded view showing the disassembly state of the shake-type mechanical pencil of FIG. 7 to explain the relationship between the operating body and each part fixed to the operating body. [Figure 10] FIG. 8 is a vertical cross-sectional view showing a state in which the chuck has advanced by operating the operating body in the shake-type mechanical pencil of FIG. 7. [Figure 11] 8 is an explanatory diagram showing a state in which the operating body is removed in the shake-type mechanical pencil of FIG. 7.

[0023] FIG. [Figure 12] 12 is a vertical end view showing a state in which the operating body has been reattached to the barrel cylinder with its front and rear direction reversed from the state shown in FIG. 11. FIG. [Figure 13] FIG. 10 is a vertical cross-sectional view showing a thermochromic writing instrument according to a third embodiment of the present invention when not in use. [Figure 14] FIG. 14 is an enlarged end view of the line CC in FIG. [Figure 15] FIG. 4 is an exploded view of the second operating body. [Figure 16] 14 is a vertical cross-sectional view showing a state in which the second operating body is moved forward from the state shown in FIG. 13. FIG. [Figure 17] 17 is a vertical end view of the third embodiment of the present invention during use, showing a state in which the second operating body has retreated from the state shown in FIG. 16. FIG. [Figure 18] 14 is an explanatory diagram for explaining a state in which the second operating body is removed from the state of FIG. 13. FIG. [Figure 19] 14 is a vertical end view showing a state in which the second operating body has been removed from the state shown in FIG. 13 and attached with the front and back reversed. FIG. DETAILED DESCRIPTION OF THE INVENTION

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

[0014] 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 should be interpreted to include a range within which similar functions can be expected.

[0015] In this specification, the direction in which the central axis of the knock-type writing instrument 1, 101, 201 extends (longitudinal direction) is referred to as the axial direction or longitudinal direction, the direction perpendicular to the axial direction is referred to as the radial direction, and the direction along the circumference around the central axis is referred to as the circumferential direction. Also, along the axial direction, the side where the front end opening of the barrel is located (the pen tip side) is referred to as the front, and the opposite direction is referred to as the rear. Also, along the radial direction, the direction toward the axis center (central axis) of the barrel is referred to as the inside or inward, and the opposite direction is referred to as the outside or outward.

[0016] (First embodiment) Although the knock-type writing instrument 1 of the first embodiment of the present invention is exemplified by a knock-type mechanical pencil, the present invention is not limited to this and can be widely used as long as it is a knock-type writing instrument.

[0017] Figure 1 is a vertical end view of a knock-type writing instrument in a first embodiment of the present invention, Figure 2 is an enlarged end view showing the AA end view of Figure 1, Figure 3 is an exploded view showing the knock-type writing instrument of Figure 1 in a disassembled state to explain the relationship between the operating body and each part fixed to the operating body, Figure 4 is a vertical cross-sectional view showing the state in which the chuck has advanced by operating the operating body in the knock-type writing instrument of Figure 1, Figure 5 is an explanatory diagram showing the state in which the operating body has been removed in the knock-type writing instrument of Figure 1, and Figure 6 is a vertical end view showing the state in which the operating body has been reattached to the barrel with its front-to-back direction reversed from the state in Figure 5.

[0018] As shown in Figures 1 and 2, the mechanical pencil 1 is composed of a barrel 2, an advance mechanism 3 equipped with a chuck 31 that holds a writing lead 8 formed of a lead core that is disposed inside the barrel 2 and serves as the writing body, and an operating body 4 that is detachably attached to the barrel 2 and protrudes rearward from the rear end opening 2c of the barrel 2, located behind the advance mechanism 3.

[0019] Barrel tube 2 has a tapered cylindrical tip opening 23, a cylindrical front barrel 21 threadedly attached to the rear of tip opening 23, and a cylindrical rear barrel 22 threadedly attached to the rear of front barrel 21, with an inner hole penetrating in the front-to-rear direction formed inside barrel 2. Grip 2a made of elastomer is integrally formed on the outer periphery of barrel tube 2 (front barrel 21) by two-color molding.

[0020] A lead holding member 24 that holds the writing lead 8 with light force is fixed to the front inner periphery of the barrel 2 (nose 23) by press-fitting or over-fitting, and a front end opening 2b is formed at the front end of the barrel 2 (nose 23) through which the writing lead 8 appears and disappears.

[0021] A rear end opening 2c is formed at the rear end of the barrel 2 (the rear end of the rear axle 22). A ferromagnetic cylindrical body 7 is press-fitted or climb-over fitted into the rear end opening 2c. This fixes the cylindrical body 7 to the barrel 2, and a mounting opening 9 is formed by the cylindrical body 7 and the inner periphery of the rear axle 22. The operating body 4, which will be described later, is detachably mounted in the mounting opening 9 and is slidable back and forth. Additionally, a restricting portion 2d with an inner step that protrudes inward is formed on the inner periphery of the barrel 2 (rear axle 22).

[0022] The lead-advancing mechanism 3 consists of a chuck 31 that clamps the writing lead 8, a lead storage tube 34 that is connected to the rear of the chuck 31 and that stores the writing lead 8, a fastener 32 that is fitted onto the head 31a of the chuck 31, a connecting device 33 that receives the fastener 32 at the rear, a spring 35 that is arranged between the connecting device 33 and the lead storage tube 34 and consists of a compression coil spring, and a cylindrical rear connecting tube 36 that is connected to the rear of the lead storage tube 34.

[0023] The chuck 31 is configured to be movable back and forth together with the lead housing tube 34 relative to the connector 33. The head 31a of the chuck 31 is divided into two parts along the axial direction, and the divided heads 31a are formed so that they gradually move apart toward the front, and the fasteners 32 cause the heads 31a to bend radially inward, allowing the writing lead 8 to be clamped.

[0024] Connector 33 is clamped between the front end of front barrel 21 and the inner section of tip 23 that is screwed onto front barrel 21, and is fixed to barrel 2. In addition, spring 35 is stretched between the inner section of connector 33 and the front end of lead accommodating tube 34, and the spring force of spring 35 springs chuck 31 and lead accommodating tube 34 backward relative to connector 33 and barrel 2.

[0025] The rear connecting tube 36 has a larger diameter at the rear than at the front, and the inner periphery is formed in a funnel shape that slopes toward the center. The rear end of the rear connecting tube is configured to abut against the front end of the operating body 4.

[0026] The operating body 4 has a cylindrical operating main body 41, a cylindrical front tube 42 press-fitted or fitted over the front outer periphery of the operating main body 41, and a tail cap 43 press-fitted or fitted over the rear inner periphery 4c of the operating main body 41.

[0027] A handwriting change member 5 equipped with a cylindrical eraser is removably attached to the front inner peripheral portion 4a of the operating body 41. The handwriting change member 5 is attached so as to protrude forward from the front end of the operating body 4, and a protruding portion 5a of the handwriting change member 5 is formed in front of the operating body 4. In addition, a rear portion 4d is formed in the rear of the operating body 4 (tail cap 43) that can come into contact with the restricting portion 2d of the barrel 2 when the operating body 4 is attached to the barrel 2 upside down.

[0028] A magnet 6 made of a permanent magnet is press-fitted or fitted onto the central inner peripheral portion 4b of the operating body 4 (operating main body 41). The axial length of the magnet 6 is formed to be approximately the same as the axial length of the cylindrical body 7 (ferromagnetic body). Furthermore, as shown in FIG. 2, the magnet 6 of this embodiment is formed so that one half of the face is an N pole 6a and the other half is an S pole 6b when viewed from the cross-sectional direction. As a result, the magnet 6 generates a strong magnetic field in the direction of the arrow in FIG. 2.

[0029] A circumferential protrusion 4e that protrudes outward and extends circumferentially is formed on the central outer periphery of the operating body 4 (operating main body 41). The circumferential protrusion 4e is formed so as to be located approximately in the center of the magnet 6 in the axial direction. This circumferential protrusion 4e prevents surface contact between the inner surface of the cylindrical body 7 or barrel 2 and the outer surface of the operating body 4, even when the operating body 4 is swung radially when sliding back and forth or when attaching or detaching the operating body 4 relative to the barrel 2, and the contact area is reduced, thereby reducing contact resistance during movement.

[0030] As described above, the operating body 4 is detachably attached to the attachment opening 9 of the barrel 2 and slidably axially. When attached, the operating body 4 is attracted to the cylindrical body 7 (ferromagnetic body) by the magnetic force of the magnet 6. At this time, the magnetic force of the magnet 6 acts strongly in the axial direction, which is the direction of the arrow in FIG. 2, and the axial lengths of the magnet 6 and the cylindrical body 7 (ferromagnetic body) are formed to be approximately the same. As a result, the magnet 6 is stably fixed by the magnetic force at approximately the same position as the cylindrical body 7 (ferromagnetic body) in the axial direction. Furthermore, when the operating body 4 is attached to the barrel 2, the front end of the operating body 4 (front tube 42) abuts against the rear end of the feeding mechanism 3 (rear connecting tube 36). Therefore, by pressing the operating body 4 forward, the rear connecting tube 36 of the feeding mechanism 3 can be pressed forward.

[0031] The handwriting change member 5 consists of an eraser 51 made of synthetic rubber and a cover 52 that is press-fitted onto the outer periphery of the eraser 51. When the handwriting change member 5 is attached to the front inner periphery 4a of the operating body 4, the outer step of the cover 52 abuts against the front end of the operating body 4, so that it does not sink any deeper and a protruding part 5a is formed.

[0032] Next, a state in which the writing lead 8 is advanced from the front end opening 2b of the barrel 2 (tip opening 23) by advancing the operating body 4 will be described with reference to FIGS. 1, when the operating body 4 is pressed forward, the rear connecting tube 36, which is in contact with the front end of the operating body 4, is also pressed forward at the same time, and the lead housing tube 34, which is connected to the rear connecting tube 36, and the chuck 31, which is connected to the lead housing tube 34, move forward relative to the barrel 2 and the connector 33 while clamping the writing lead 8 against the elastic force of the elastic body 35, and the writing lead 8 is dispensed from the front end opening 2b of the barrel 2. At this time, as the chuck 31 moves forward, the fastener 32 fitted onto the head 31a of the chuck 31 also moves forward, but when the front end of the fastener 32 comes into contact with the inner step 2e of the barrel 2 (nose 23), the fastener 32 disengages from the head 31a of the chuck 31, the head 31a expands, and the clamped state of the writing lead 8 is released, and the forward movement of the writing lead 8 stops. Then, when the pressure on the operating body 4 toward the front is released, the chuck 31 moves backward due to the elastic force of the elastic body 35, and the fastener 32 is once again fitted onto the head 31a, causing the writing lead 8 to be clamped by the chuck 31. At this time, even in the forward state, the operating body 4 is pulled backward by the magnetic force acting between the magnet 6 and the cylindrical body 7 until the axial positions of the magnet 6 and the cylindrical body 7 are aligned. For this reason, there is no need for the elastic body 35 to elastically urge the operating body 4 backward, and the elastic force of the elastic body 35 can be reduced by the weight of the operating body 4.

[0033] Next, the state of removing the operating body 4 from the barrel 2 and reattaching it to the barrel 2 will be described with reference to FIGS. 1 and 5. In the knock-type writing instrument 1 of this embodiment, the operating body 4 can be removed from the barrel 2 from the state shown in FIG. 1 by grasping the operating body 4 and pulling it backward against the magnetic force acting between the magnet 6 and the cylindrical body 7 (ferromagnetic material), as shown in FIG. 5. At this time, the handwriting change member 5 is pulled out along with the operating body 4 and exposed to the outside, so the operating body 4 serves as a gripping part, allowing for a firm grip. Handwriting made with the lead 8, which is a lead, can be removed from the writing surface by rubbing it with the handwriting change member 5 (eraser 51). Furthermore, when the operating body 4 is removed from the barrel 2, the rear of the rear connecting tube 36 is open. Therefore, by inserting a refill lead into the barrel 2 through the rear end opening 2c of the barrel 2, the lead can be refilled into the lead receiving tube 34 through the funnel-shaped rear inner peripheral portion of the rear connecting tube 36. When the removed operating body 4 is then brought close to the attachment opening 9 of the barrel 2 from the handwriting change member 5, the operating body 4 is attracted into the barrel 2 by the magnetic force of the magnet 6 and is adsorbed to the original position shown in Figure 1. When this attachment is performed, the rear end of the feeding mechanism 3 (rear connecting barrel 36) and the front end of the operating body 4 (front barrel 42) come into contact. Therefore, by configuring the device to generate a "click" sound when they come into contact, the user can hear that the attachment of the operating body 4 is complete.

[0034] Furthermore, in this embodiment, when reattaching the operating body 4 to the barrel 2 after it has been pulled out as shown in Figure 5, the operating body 4 can be attached to the barrel 2 even if the front-to-back direction is reversed. When the operating body 4 is reversed and brought closer to the attachment opening 9 of the barrel 2 from the rear end (tail cap 43), the operating body 4 is attracted to the tubular body 7 (ferromagnetic body) of the barrel 2 by the magnetic force of the magnet 6, just as when it is attached from the handwriting change member 5 side, resulting in the attached state shown in Figure 6. In this state of Figure 6, the restricting portion 2d of the barrel 2 and the rear part 4d of the operating body 4 abut against each other, and the operating body 4 is attached to the barrel 2 with the protruding portion 5a of the handwriting change member 5 protruding rearward from 2c of the barrel 2. Therefore, when rubbing the handwriting made by the writing lead 8 with the handwriting changing member 5 (eraser 51) in the state of Figure 6, the rubbing action can be performed by grasping the barrel 2, and since the barrel diameter of the barrel 2 is larger than that of the operating body 4, it is easier to apply force than when rubbing by grasping the operating body 4. Therefore, the rubbing action can be performed easily and the handwriting can be removed.

[0035] In this embodiment, the material constituting the cylindrical body 7 (ferromagnetic body) is one that is attracted by the magnetic force of the magnet 6, and it is preferable to use a substance that is strongly magnetized by a magnetic field and remains magnetized even when the magnetic field is removed, such as iron, cobalt, nickel and their alloys, ferrite, etc.

[0036] In this embodiment, a knock-type writing instrument 1 has been provided in which the operating body 4 removed from the barrel 2 can be easily and reliably reattached to the barrel 2 using magnetic force without causing any malfunction in the advancement mechanism 3.

[0037] The knock-type writing instrument 1 of this embodiment comprises a barrel 2, a writing body 8 housed inside the barrel 2 and having a writing part at its tip, an advancing mechanism 3 that advances the writing body 8 forward, and an operating body 4 located behind the advancing mechanism 3 and operating the advancing mechanism 3. It has a handwriting change member 5 that is engaged in front of the operating body 4 and is used to remove, thermally discolor or conceal handwriting written with the writing body 8, and at least a portion of the operating body 4 protrudes from the barrel 2, and is attached to the barrel 2 so that it can slide back and forth and be detached by the magnetic force acting between the barrel 2 and the operating body 4.

[0038] According to this knock-type writing instrument 1, the operating body 4, which operates the feeding mechanism 3 for feeding the writing element 8, is magnetically slidably and detachably attached to the barrel 2, and since the operating mechanism does not have a locking or press-fit structure, the operating mechanism is not pressed when attached, preventing the feeding mechanism 3 from being unintentionally activated and feeding out the writing element 8. In addition, since the handwriting change member 5 is located in front of the operating body 4, removing the operating body 4 from the barrel 2 can simultaneously remove the handwriting change member 5, and gripping the operating body 4 will not soil the handwriting change member 5 with hand oils or the like, and furthermore, the ability to grip it firmly makes it easy to erase or discolor written handwriting or to conceal handwriting. Furthermore, since the handwriting change member 5 can be stored in the barrel 2 when not in use, when not in use or when carried in a bag or pencil case, the handwriting change member 5 is prevented from being damaged or soiled by other items, and the handwriting change member 5 is prevented from damaging or soiling other items.

[0039] The handwriting changer 5 in this embodiment can be a synthetic rubber eraser that removes handwriting made with a lead core by rubbing it, a friction body made of an elastic material that changes color from colored to colored or from colorless to colorless due to frictional heat when rubbing handwriting made with thermochromic ink or a solid core, a correction fluid that conceals handwriting by applying paint over it, or correction tape that conceals handwriting by applying tape over it. More preferably, an eraser or friction body material that does not require a large space and can be easily attached is used. The knock-type writing instrument 1 of this embodiment can be used in knock-type mechanical pencils, ballpoint pens, markers, fountain pens, multi-lead writing instruments, etc. The elastic material constituting the friction body is preferably a synthetic resin (rubber, elastomer) having elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, ethylene propylene diene rubber (EPDM), etc.

[0040] In the knock-type writing instrument 1 of this embodiment, a magnet 6 is provided on either the barrel 2 or the operating body 4, and a ferromagnetic body 7 that is magnetically attracted by the magnetic force of the magnet 6 is provided on the other.

[0041] According to this knock-type writing instrument 1, the magnetic force generated by the magnet 6 provided on either the barrel 2 or the operating body 4 attracts the ferromagnetic body 7 provided on the other, so that the operating body 4 can be fixed to the barrel 2 by magnetic force without using a press-fit or locking structure. When the operating body 4 is attached to the barrel 2 by magnetic force, it is preferable to adjust the magnetic force, magnetic field, shapes, and distance between the magnet 6 and the ferromagnetic body 7 so that the axial position of the operating body 4 relative to the barrel 2 is stable. This makes it possible to prevent the operating mechanism from malfunctioning when the operating body 4 presses the operating mechanism forward when attached to the barrel 2.

[0042] The ferromagnetic material 7 in this embodiment refers to a material that is strongly magnetized by a magnetic field and remains magnetized even after the magnetic field is removed, such as iron, cobalt, nickel, alloys thereof, and ferrite.

[0043] In the knock-type writing instrument 1 of this embodiment, the operating body 4 is operated to activate the advancement mechanism 3, and when the distance between the magnet 6 and the ferromagnetic body 7 is maximized, the operating body 4 returns to its position before operation solely due to the magnetic force acting between the magnet 6 and the ferromagnetic body 7.

[0044] With such a knock-type writing instrument 1, even if the operating body 4 is advanced by a pressing action or the like, the operating body 4 returns to its original position by magnetic force, so there is no need to bias the operating body 4 with a compression spring such as a coil spring, and the configuration of the operating mechanism can be simplified and costs can be reduced.

[0045] In the knock-type writing instrument 1 of this embodiment, when the operating body 4 is removed from the barrel 2, it can be detachably attached to the barrel 2 by magnetic force even if the front and rear directions of the operating body 4 are reversed.

[0046] According to such a knock-type writing instrument 1, the handwriting change member 5 engaged with the operating body 4 is configured to protrude rearward from the rear end of the barrel 2, which prevents the removed operating body 4 from being lost or damaged, and since the handwriting change member 5 can be used to remove, discolor or conceal handwriting by gripping the barrel 2, it is preferable to grip the barrel 2, which is at least thicker than the operating body 4, as this allows for a firmer grip and makes it easier to apply force.

[0047] In the knock-type writing instrument 1 of this embodiment, when the operating body 4 is attached to the barrel 2 upside down, the operating body 4 comes into contact with the restricting portion 2d that restricts the operating body 4 from moving forward.

[0048] With such a knock-type writing instrument 1, even if force is applied when using the handwriting change member 5, the handwriting change member 5 can be prevented from advancing and sinking into the barrel 2 together with the operating body 4, so that more force can be applied when using the handwriting change member 5.

[0049] This embodiment has been able to provide a knock-type writing instrument 1 that allows the operating body 4 detached from the feeding mechanism 3 of the writing body 8 to be easily and reliably attached to the feeding mechanism 3.

[0050] In this embodiment, the handwriting changing member 5 is exemplified as a synthetic rubber eraser for erasing lead from a mechanical pencil, but this embodiment is not limited to this. For example, an elastic friction body may be used to thermally change the color of handwriting made with thermochromic ink or thermochromic solid lead from colored to colorless or from colored to colored by frictional heat caused by rubbing, or correction fluid may be used to cover up handwriting by applying paint over it, or correction tape may be used to cover up handwriting by applying tape over it.

[0051] The knock-type writing implement of this embodiment can be widely used as a knock-type writing implement, and can be employed in knock-type ballpoint pens, markers, fountain pens, multi-lead writing implements, and the like in addition to knock-type mechanical pencils.

[0052] (Second embodiment) Figure 7 is a vertical end view of a dispenser mechanical pencil in a second embodiment of the present invention, Figure 8 is an enlarged end view showing the BB end face of Figure 7, Figure 9 is an exploded view showing the dispenser mechanical pencil of Figure 7 in a disassembled state to explain the relationship between the operating body and each part fixed to the operating body, Figure 10 is a vertical cross-sectional view showing the state in which the chuck has advanced by operating the operating body in the dispenser mechanical pencil of Figure 7, Figure 11 is an explanatory diagram showing the state in which the operating body has been removed in the dispenser mechanical pencil of Figure 7, and Figure 12 is a vertical end view showing the state in which the operating body has been reattached to the barrel with its front-to-back direction reversed from the state in Figure 11.

[0053] As shown in Figures 7 and 8, the dispensing mechanical pencil 101 is composed of a barrel 102, a lead-advancing mechanism 103 equipped with a chuck 131 that clamps a writing lead 108 formed of a lead core that is arranged inside the barrel 102 and serves as the writing body, and a lead-accommodating member (lead-accommodating tube) 134 that accommodates the writing lead 108, a weight 110 that is loosely fitted into the lead-accommodating member 134 so as to be movable back and forth, and an operating body 104 that is arranged behind the lead-advancing mechanism 103, is detachably attached to the barrel 102, and protrudes rearward from a rear end opening 102c of the barrel 102.

[0054] Barrel tube 102 has a tapered cylindrical tip opening 123, a cylindrical front barrel 121 threadedly attached to the rear of tip opening 123, and a cylindrical rear barrel 122 threadedly attached to the rear of front barrel 121, and an inner hole penetrating in the front-to-rear direction is formed inside barrel tube 102. Grip 102a made of elastomer is integrally formed by two-color molding on the outer periphery of barrel tube 102 (front barrel 22).

[0055] A lead holding member 124 that holds the writing lead 108 with light force is fixed to the front inner periphery of the barrel 102 (nose 123) by press-fitting or over-fitting, and a front end opening 102b is formed at the front end of the barrel 102 (nose 123) through which the writing lead 108 appears and disappears.

[0056] A rear end opening 102c is formed at the rear end of the barrel 102 (the rear end of the rear axle 122). A ferromagnetic cylindrical body 107 is press-fitted or climb-over fitted into the rear end opening 102c. This fixes the cylindrical body 107 to the barrel 102, and a mounting opening 109 is formed by the cylindrical body 107 and the inner periphery of the rear axle 122. An operating body 104, which will be described later, is detachably mounted in the mounting opening 109 and is slidable back and forth. In addition, a step-shaped restricting portion 102d that protrudes inward is formed on the inner periphery of the barrel 102 (rear axle 122), and a protrusion 102f that also protrudes inward is formed in front of the restricting portion 102d.

[0057] The lead-advancing mechanism 103 has a chuck 131 that clamps the writing lead 108, a cylindrical connector 137 connected to the rear of the chuck 131, a lead holding member 134 that is connected to the rear of the connector 137 and holds the writing lead 108, a fastener 132 fitted onto the head 131a of the chuck 131, a connecting member 133 that receives the fastener 132 at the rear, a spring 135 that is arranged between the connecting member 133 and the lead holding member 134 and is made of a compression coil spring, and a cylindrical rear connecting tube 136 that is connected to the rear of the lead holding member 134.

[0058] The chuck 131, together with the connector 137 and the lead accommodating member 134, is configured to be movable back and forth relative to the connecting device 133. The head 131a of the chuck 131 is divided into two parts along the axial direction, and the divided heads 131a are formed so that they gradually move apart toward the front, and the heads 131a are each bent radially inward by the fastener 132, allowing the writing lead 108 to be clamped.

[0059] Connector 137 has elastic pieces extending circumferentially from the base at two opposing locations on the base, approximately in the middle of connector 137. Furthermore, abutment portions 137a projecting axially rearward are formed at the tip of each of the two elastic pieces. The front end of weight body 110 is configured to abut against abutment portions 137a, and when weight body 110 advances and abuts against abutment portion 137a, the elastic pieces flex to absorb the impact force at the time of abutment, thereby reducing contact noise. The force is also transmitted to chuck 131 and lead housing member 134 via connector 137, causing chuck 131 and lead housing member 134 to advance, allowing writing lead 108 housed in lead housing member 134 to be gripped by chuck 131 and advanced forward.

[0060] Connector 133 is formed in a ring shape, and is fixed to barrel 102 by being clamped between the front end of front barrel 121 and the inner section of tip 123 that is screwed onto front barrel 121. In addition, elastic body 135 is stretched between the inner section of connector 133 and the front end of lead accommodating member 134, and the elastic force of elastic body 135 elastically urges chuck 131, connector 137, and lead accommodating member 134 rearward relative to connector 133 and barrel 102.

[0061] The rear connecting tube 136 has a larger diameter at the rear than at the front, and the inner periphery is formed in a funnel shape that slopes toward the center. The rear end of the rear connecting tube is configured to abut against the front end of the operating body 104.

[0062] The weight body 110 is made of stainless steel and formed into a cylindrical shape, and is loosely fitted between the outer periphery of the lead accommodating member 134 and the inner periphery of the barrel 102. When the weight body 110 moves forward, it comes into contact with the abutment portion 137a of the connector 137, and when the weight body 110 moves backward, it comes into contact with the protrusion 102f of the barrel 102.

[0063] The operating body 104 has a cylindrical operating main body 141, a cylindrical front tube 142 press-fitted or fitted over the front outer periphery of the operating main body 141, and a tail cap 143 press-fitted or fitted over the rear inner periphery 104c of the operating main body 141.

[0064] A rubbing member (handwriting change member) 105 equipped with a cylindrical eraser is removably attached to the front inner peripheral portion 104a of the operating body 141. The rubbing member 105 is attached so as to protrude forward from the front end of the operating body 104, and a protruding portion 105a of the rubbing member 105 is formed in front of the operating body 104. In addition, a rear portion 104d is formed in the rear of the operating body 104 (tail cap 143) so as to be able to come into contact with the restricting portion 102d of the barrel 102 when the operating body 104 is attached to the barrel 102 upside down.

[0065] A magnet 106 made of a permanent magnet is press-fitted or fitted onto the central inner peripheral portion 104b of the operating body 104 (operating main body 141). The axial length of the magnet 106 is formed to be approximately the same as the axial length of the cylindrical body 107 (ferromagnetic body). Furthermore, as shown in FIG. 8, the magnet 106 of this embodiment is formed so that one half of the face is an N pole 106a and the other half is an S pole 106b when viewed from the cross-sectional direction. As a result, the magnet 106 generates a strong magnetic field in the direction of the arrow in FIG. 8.

[0066] A circumferential protrusion 104e that protrudes outward and extends circumferentially is formed on the central outer periphery of the operating body 104 (operating main body 141). The circumferential protrusion 104e is formed so as to be located approximately in the center of the magnet 106 in the axial direction. This circumferential protrusion 104e prevents surface contact between the inner surface of the cylindrical body 107 or the barrel 102 and the outer surface of the operating body 104, even if the operating body 104 is swung radially when sliding the operating body 104 back and forth or when attaching or detaching the operating body 104 relative to the barrel 102, and the contact area is reduced, thereby reducing contact resistance during movement.

[0067] As described above, the operating body 104 is detachably attached to the attachment opening 109 of the barrel 102 and slidably axially. When attached, the operating body 104 is attracted to the cylindrical body 107 (ferromagnetic body) by the magnetic force of the magnet 106. At this time, the magnetic force of the magnet 106 acts strongly in the axial direction, which is the direction of the arrow in FIG. 8, and the axial lengths of the magnet 106 and the cylindrical body 107 (ferromagnetic body) are formed to be approximately the same. As a result, the magnet 106 is stably fixed by the magnetic force at approximately the same position as the cylindrical body 107 (ferromagnetic body) in the axial direction. Furthermore, when the operating body 104 is attached to the barrel 102, a gap is formed between the front end of the operating body 104 (front barrel 142) and the rear end of the lead advancing mechanism 103 (rear connecting barrel 136). Furthermore, when the operating body is pushed forward, the front part of the advanced operating body 104 (front tube 142) comes into contact with the rear end of the lead advancing mechanism 103 (rear connecting tube 136), and therefore the lead advancing mechanism 103 (rear connecting tube 136) can be pushed forward by pushing the operating body 104 forward. At this time, the protruding part 105a of the scraping member 105 is inserted into the rear inner hole of the lead advancing mechanism 103 (rear connecting tube 136), but the scraping member 105 and the lead advancing mechanism 103 (rear connecting tube 136) are configured not to come into contact with each other.

[0068] The rubbing member 105 is made of an eraser 151 made of synthetic rubber, and a cover 152 that is press-fitted onto the outer periphery of the eraser 151. When the rubbing member 105 is attached to the front inner periphery 104a of the operating body 104, the outer step of the cover 152 abuts against the front end of the operating body 104, so that the rubbing member 105 does not sink any deeper, and a protrusion 105a is formed.

[0069] Next, a state in which the writing lead 108 is advanced from the front end opening 102b of the barrel 102 (tip opening 123) by advancing the operating body 104 will be described with reference to FIGS. 7, when the operating body 104 is pressed forward, the operating body 104 moves forward against the magnetic force acting between the magnet 106 and the cylindrical body 107. Then, the front part of the moving forward operating body 104 abuts against the rear end of the rear connecting tube 136 and presses it forward, and the lead accommodating member 134, connector 137, and chuck 131 connected to the rear connecting tube 136 move forward relative to the barrel 102 and connecting device 133 while clamping the writing lead 108 against the elastic force of the elastic body 135, and the writing lead 108 is fed out from the front end opening 102b of the barrel 102. At this time, as the chuck 131 moves forward, the fastener 132 fitted onto the head 131a of the chuck 131 also moves forward, but the front end of the fastener 132 abuts against the inner step 102e of the barrel 102 (nose 123), causing the fastener 132 to disengage from the head 131a of the chuck 131, causing the head 131a to expand, releasing the clamped state of the writing lead 108 and stopping the forward movement of the writing lead 108. Then, when the forward pressure of the operating body 104 is released, the chuck 131 moves backward due to the elastic force of the elastic body 135, and the fastener 132 is once again fitted onto the head 131a, causing the writing lead 108 to be clamped by the chuck 131. At this time, even in the advanced state, the operating body 104 is pulled backward by the magnetic force acting between the magnet 106 and the cylindrical body 107 until the axial positions of the magnet 106 and the cylindrical body 107 are aligned. Therefore, there is no need to use the spring 135 to spring the operating body 104 backward, and the operating body 104 can be automatically returned to its original position by magnetic force.

[0070] The writing lead 108 can also be extended by swinging the barrel back and forth. When the barrel 102 is grasped and swung back and forth from the state shown in Figure 7, inertial force acts on the weight body 110, which is loosely fitted inside the barrel 102, causing it to slide back and forth. When the weight body 110, which is moved forward by inertial force, comes into contact with the abutment portion 137a of the connector 137, the connector 137 can be moved forward together with the chuck 131 and the lead accommodating member 134, and this makes it possible to advance the writing lead 108 forward in the same way as when the operating body 104 is advanced. Note that when the barrel 102 is swung back and forth, the weight body 110 is fixed by the magnetic force acting between the magnet 106 and the cylindrical body 107 (a ferromagnetic material), and the operating body 104 and the lead advancing mechanism 103 do not come into contact with each other.

[0071] Next, a state in which the operating body 104 is removed from the barrel 102 and then reattached to the barrel 102 will be described. In the dispenser-type mechanical pencil 101 of this embodiment, from the state shown in FIG. 7, the operating body 104 can be pulled out of the barrel 102 as shown in FIG. 11 by grasping the operating body 104 and pulling it backward against the magnetic force acting between the magnet 106 and the cylindrical body 107 (ferromagnetic body). At this time, the rubbing member 105 is pulled out together with the operating body 104 and exposed to the outside. Therefore, the operating body 104 serves as a gripping portion, allowing it to be firmly gripped, and handwriting made by the lead 108, which is a lead core, can be removed from the writing surface by rubbing it with the rubbing member 105 (eraser 151). Furthermore, when the operating body 104 is detached from the barrel 102, the rear of the rear connecting tube 136 is open, and so by inserting a refill lead into the barrel 102 through the rear end opening 102c of the barrel 102, the lead can be replenished into the lead accommodating member 134 through the funnel-shaped rear inner periphery of the rear connecting tube 136. When the detached operating body 104 is brought closer to the attachment opening 109 of the barrel 102 from the rubbing member 105, the operating body 104 is attracted into the barrel 102 by the magnetic force of the magnet 106 and is adsorbed to the position shown in FIG. 7. When attached in this manner, the rear end of the lead advancing mechanism 103 (rear connecting tube 136) does not come into contact with the front end of the operating body 104 (front tube 142), and the rear connecting tube 136 is not pressed by the operating body 104, preventing the lead advancing mechanism 103 from malfunctioning and the writing lead 108 from being unintentionally advanced.

[0072] Furthermore, in this embodiment, when reattaching the operating body 104 to the barrel 102 after it has been pulled out as shown in Fig. 11, the operating body 104 can be attached to the barrel 102 even if the front-to-back direction of the operating body 104 is reversed. When the operating body 104 is reversed and brought closer to the attachment opening 109 of the barrel 102 from the rear end (tail plug 43) side, the operating body 104 is attracted to the tubular body 107 (ferromagnetic body) of the barrel 102 by the magnetic force of the magnet 106, just as when it is attached from the scraping member 105 side, resulting in the attached state shown in Fig. 12. In this state of Fig. 12, the restricting portion 102d of the barrel 102 and the rear part 104d of the operating body 104 are in contact with each other, and the protruding portion 105a of the scraping member 105 protrudes rearward from the rear end opening 102c of the barrel 102, and the operating body 104 is attached to the barrel 102. Therefore, when rubbing the handwriting of the writing lead 108 with the rubbing member 105 (eraser 151) in the state shown in FIG. 12 , the user can grip the barrel 102 and perform the rubbing operation. Because the barrel 102 has a larger shaft diameter than the operating body 104, it is easier to apply force than when gripping the operating body 104. This makes it easier to perform the rubbing operation and remove the handwriting. In the state shown in FIG. 12 , the rear section 104d of the operating body 104 abuts against the restricting section 102d of the barrel 102, so the writing lead 108 cannot be advanced by pushing the operating body 104 forward. However, by swinging the barrel 102 back and forth, the generated inertial force advances the weight body 110, which advances the chuck 131 via the connector 137, thereby advancing the writing lead 108, further improving convenience.

[0073] In this embodiment, the material constituting the cylindrical body (ferromagnetic body) 107 is one that is attracted by the magnetic force of the magnet 106, and it is preferable to use a substance that is strongly magnetized by a magnetic field and remains magnetized even when the magnetic field is removed, such as iron, cobalt, nickel and their alloys, ferrite, etc.

[0074] The dispensing mechanical pencil 101 of this embodiment uses a magnet 106 to realize a simple structure for attaching the operating body 104 to the barrel 102, and also makes it possible to easily expose and use the rubbing member 105 (eraser 151) housed inside the barrel 102.

[0075] In this embodiment, the rubbing member 105 is exemplified as a synthetic rubber eraser for removing lead from a mechanical pencil, but this embodiment is not limited to this. For example, an elastic friction body may be used that thermally changes the color of handwriting made with a thermochromic solid lead from colored to colorless or from colored to colored by frictional heat caused by rubbing. The elastic material constituting the friction body is preferably an elastic synthetic resin (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, ethylene propylene diene rubber (EPDM), etc.

[0076] [1] In this embodiment, a knock-type writing implement (dispensing mechanical pencil) 101 includes a barrel 102, a chuck 131 that clamps a writing lead 108, a cylindrical lead housing member 134 that houses the writing lead 108, and a lead-advancing mechanism 103 that includes a weight body 110 that is slidably attached to the lead housing member 134 back and forth along the axial direction. The lead-advancing mechanism 103 is operated by pressing the weight body 110 forward, or by swinging the barrel 102 back and forth, which moves the weight body 110 due to the inertial force. The lead-advancing mechanism 103 is operated by pressing the weight body 110 forward, or by swinging the barrel 102 back and forth. The knock-type writing implement (dispensing mechanical pencil) 101 advances a writing lead 108 from a front end opening 102b of the barrel 102, the operating body 104 is attached to the barrel 102 by magnetic force so as to be freely slidable back and forth and detachable, and has an abrading member 105 that is engaged with the front part of the operating body 104 and removes or thermally discolors handwriting written with the writing lead 108, the operating body 104 is configured so that there is a gap between the operating body 104 and the lead holding member 134 when not in operation, and is configured so that the operating body 104 can abut against the rear end of the lead holding member 134 when moved forward during operation.

[0077] According to this knock-type writing implement 101, the operating body 104 that operates the lead advancing mechanism 103 for advancing the writing lead 108 is magnetically and detachably attached to the barrel 102, and because the lead housing member 134 of the lead advancing mechanism 103 and the operating body 104 are attached in a spaced-apart state, the operating body 104 does not press the lead housing member 134 when attached and activate the operating mechanism, preventing the lead advancing mechanism 103 from accidentally operating and advancing the writing lead 108. Furthermore, because the operating body 104 is magnetically and detachably attached to the barrel 102, there is no need for a locking or press-fit structure for the operating mechanism, and the operating body 104 can be automatically attracted by magnetic force by simply bringing it close to the barrel 102 without requiring a complex structure, and furthermore, it is possible to prevent the operating body 104 from being attached to the barrel 102 in an incomplete state. Furthermore, since the rubbing member 105 is engaged at the front part of the operating body 104, the rubbing member 105 can be easily exposed to the outside by removing the operating body 104 from the barrel 102, and the rubbing member 105 will not be soiled with hand oils or the like by gripping the operating body 104, and the ability to grip it firmly has the effect of making it easier to apply force when performing a rubbing operation with the rubbing member 105 to remove handwriting or thermally discolor it.

[0078] Furthermore, since the operating body 104 is fixed to the barrel 102 by magnetic force with the lead holding member 134 and the operating body 104 spaced apart, the weight of the operating body 104 is prevented from being transmitted to the chuck 131 via the lead holding member 134, thereby preventing any effect on the clamping force of the chuck 131 on the writing lead 108.

[0079] The writing lead 108 in this embodiment is not particularly limited as long as it is a lead body that can be stored in a mechanical pencil and can be extended and used for writing, but suitable examples include lead leads and colored solid leads that can be removed from the writing surface by rubbing the writing, and thermochromic solid leads that change color from colored to colored or from colored to colorless by heating the writing.

[0080] The rubbing member 105 in this embodiment may be a synthetic rubber eraser that removes handwriting with a lead core or a colored solid core by rubbing, or a friction body made of an elastic material that changes color from color to color or from color to colorless by heat when rubbing handwriting with a thermochromic solid core. The elastic material constituting the friction body is preferably an elastic synthetic resin (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, ethylene propylene diene rubber (EPDM), etc.

[0081] [2] The knock-type writing instrument (dispensing mechanical pencil) 101 of this embodiment is the knock-type writing instrument (dispensing mechanical pencil) 101 described in [1], which has a magnet 106 on either the barrel 102 or the operating body 104, and a ferromagnetic body 107 on the other that is attracted by the magnetic force of the magnet 106.

[0082] According to this knock-type writing instrument 101, the magnetic field generated by the magnet 106 provided on either the barrel 102 or the operating body 104 attracts the ferromagnetic body 107 provided on the other, so that the operating body 104 can be fixed to the barrel 102 by magnetic force without using a press-fit or locking structure. When the operating body 104 is attached to the barrel 102 by magnetic force, it is preferable to adjust the magnetic force, magnetic field, shapes, and distance between the magnet 106 and the ferromagnetic body 107 so that the axial position of the operating body 104 relative to the barrel 102 is stable. This prevents the operating mechanism from malfunctioning when the operating body 104 presses the operating mechanism forward when the operating body 104 is attached to the barrel 102, and allows the operating body 104 to be attached with a reliable distance between the operating body 104 and the lead housing member 134 of the operating mechanism.

[0083] In this embodiment, the ferromagnetic material 107 refers to a material that is strongly magnetized by a magnetic field and remains magnetized even after the magnetic field is removed, such as iron, cobalt, nickel, alloys thereof, and ferrite.

[0084] In addition, the operating body 104 may be operated to activate the dispensing mechanism, and when the operating body 104 moves forward to maximize the distance between the magnet 106 and the ferromagnetic body 107, the operating body 104 may be configured to return to the position it was in before operation solely by the magnetic force acting between the magnet 106 and the ferromagnetic body 107. In this case, even if the operating body 104 is moved forward by a pressing operation or the like, the operating body 104 returns to its original position by the magnetic force, so there is no need to bias the operating body 104 with a compression spring such as a coil spring, and the mounting structure of the operating body 104 can be simplified to reduce costs.

[0085] [3] The knock-type writing instrument (dispensing mechanical pencil) 101 of this embodiment is a knock-type writing instrument (dispensing mechanical pencil) 101 described in [1] or [2], in which, when the operating body 104 is removed from the barrel 102, the operating body 104 can be attached and detached to the barrel 102 by magnetic force even if the front-to-back direction of the operating body 104 is reversed.

[0086] [4] The knock-type writing instrument (dispensing mechanical pencil) 101 of this embodiment is the knock-type writing instrument (dispensing mechanical pencil) 101 described in [3], in which, when the operating body 104 is attached to the barrel 102 with the front and rear reversed, at least a part of the rubbing member 105 engaged with the operating body 104 protrudes outward from the barrel 102.

[0087] According to such a knock-type writing instrument 101, the rubbing member 105 engaged with the operating body 104 is configured to protrude rearward from the rear end of the barrel 102, which prevents the detached operating body 104 from being lost or damaged, and also allows the barrel 102 to be grasped when using the rubbing member 105 to remove or discolor handwriting, so that grasping the barrel 102, which is at least thicker than the operating body 104, allows for a firmer grip and makes it easier to apply force, which is preferable.

[0088] [5] The knock-type writing instrument (dispensing mechanical pencil) 101 of this embodiment is the knock-type writing instrument (dispensing mechanical pencil) 101 described in [3] or [4], in which, when the operating body 104 is attached to the barrel 102 with the front and rear reversed, the operating body 104 abuts against the regulating portion 102d that regulates the forward movement of the operating body 104.

[0089] According to such a knock-type writing implement 101, even if force is applied when using the rubbing member 105, the rubbing member 105 together with the operating body 104 can be prevented from advancing and sinking into the barrel 102, so that more force can be applied when using the rubbing member 105.

[0090] This embodiment realizes a simple structure for attaching the operating body 104 to the barrel 102, and provides a knock-type writing instrument (dispensing mechanical pencil) 101 that can easily expose and use the rubbing member 105 housed inside the barrel 102.

[0091] (Third embodiment) A third embodiment of the present invention is shown in Figures 13 to 19. Figure 13 is a vertical cross-sectional view showing a thermochromic writing instrument according to this embodiment when not in use, Figure 14 is an enlarged end view of line CC in Figure 13, Figure 15 is an exploded view of a second operating body according to this embodiment, Figure 16 is a vertical cross-sectional view showing a state in which the second operating body has been advanced from the state in Figure 13, Figure 17 is a vertical end view of this embodiment when in use and shows a state in which the second operating body has been retracted from the state in Figure 16, Figure 18 is an explanatory view for explaining a state in which the second operating body has been removed from the state in Figure 13, and Figure 19 is a vertical end view showing a state in which the second operating body has been removed from the state in Figure 13 and attached upside down.

[0092] The thermochromic writing instrument 201 of this embodiment comprises a barrel 202, a writing body 203 housed within the barrel 202, a first operating body 204 protruding radially outward from the outer surface of the barrel 202, and a retraction mechanism that allows the pen tip 231 of the writing body 203 to freely protrude and retract from the front end hole 227 of the barrel 202 by sliding the first operating body 204 forward.

[0093] The writing element 203 comprises a pen tip 231, an ink reservoir 232 into whose front end opening the pen tip 231 is press-fitted, thermochromic ink filled in the ink reservoir 232, and a follower (e.g., a high-viscosity fluid) filled at the rear end of the thermochromic ink and which advances as the thermochromic ink is consumed.

[0094] The pen tip 231 may, for example, consist of only a metal ballpoint pen tip that rotatably holds a ball at its front end, or a synthetic resin pen tip holder that holds the rear outer surface of the ballpoint pen tip. A tail plug 233 with a vent hole that allows ventilation between the ink reservoir 232 and the outside is attached to the rear end opening of the ink reservoir 232. A spring that presses the ball at the front end forward is housed inside the pen tip 231. The spring is a compression coil spring with a rod portion at the front end, and the front end of the rod portion contacts the rear surface of the ball. When not writing, the forward bias of the spring brings the ball into close contact with the inner surface of the inward-facing front edge of the ballpoint pen tip, preventing ink leakage from the front end of the pen tip 231 and ink evaporation.

[0095] The barrel 202 is made up of a tapered cylindrical front axle 221, a cylindrical center axle 222 threadedly attached to the rear of the front axle, and a cylindrical rear axle 223 connected to the rear end of the center axle 222. A slide hole 224 extending in the front-rear direction and penetrating radially is formed in a rear side wall 229 of the barrel 202 (the side wall of the center axle 222 and rear axle 223). A cam portion 226 is formed integrally with the inner surface of the barrel 202 (center axle 222), and a stepped restriction portion 228 protruding inward is formed on the inner surface of the rear axle 223 behind the cam portion 226.

[0096] A rear end opening 225 is formed at the rear end of the barrel 202 (the rear end of the rear axle 223). A tubular body 209 made of a ferromagnetic material is press-fitted or climb-over fitted into the rear end opening 225. This fixes the tubular body 209 to the barrel 202, and forms an attachment opening 210 made up of the tubular body 209 and the inner periphery of the rear axle 223. A second operating body 205, which will be described later, is attached to the attachment opening 210 so that it can slide back and forth and be detachable.

[0097] The first operating body 204 includes an operating portion 241 that protrudes outward from the slide hole 224 of the barrel tube 202, a base 242 that is integrally connected to the operating portion 241, a shaft portion 243 that is integrally connected to the base 242 and extends forward from the base 242, and a rear hole 244 that extends forward from the rear end of the base 242. The first operating body 204 is obtained by molding a synthetic resin (e.g., polycarbonate resin). Cam teeth that engage with the rotating member 207 are formed on the front end of the shaft portion 243, either integrally or attached as a separate member. The rear hole 244 is formed so that the friction body 206, which will be described later, can be inserted therein, and the front end of the friction body 206 abuts against a bottom 245 of the rear hole 244.

[0098] The second operating body 205 has a cylindrical operating main body 251 and a tail cap 252 that is press-fitted or jump-fitted onto a rear inner periphery 255 of the operating main body 251. A friction body 206 made of an elastic material is engaged with a front inner periphery 253 of the operating main body 251 by press-fitting or jump-fitting. The friction body 206 protrudes forward from the front end of the second operating body 205, and a protruding portion 261 of the friction body 206 is formed in front of the second operating body 205, and the top of the protruding portion 261 is formed into a convex curved surface. In addition, a rear portion 256 that can abut against the restricting portion 228 of the barrel 202 when the second operating body 205 is attached to the barrel 202 upside down is formed on the rear portion of the second operating body 205 (tail cap 252).

[0099] A magnet 208 made of a permanent magnet is press-fitted or jump-fitted into the central inner peripheral portion 254 of the second operating body 205 (operation main body 251). The axial length of the magnet 208 is formed to be substantially the same as the axial length of the cylindrical body 209 (ferromagnetic body). Furthermore, as shown in FIG. 14, the magnet 208 of this embodiment is formed so that one half of the face is an N pole 281 and the other half is an S pole 282 when viewed from the cross-sectional direction. As a result, the magnet 208 generates a strong magnetic field in the direction of the arrow in FIG. 14.

[0100] As described above, the second operating body 205 is detachably attached to the attachment opening 210 of the barrel 202 and slidably axially. When attached, the second operating body 205 is attracted to the cylindrical body 209 (ferromagnetic body) by the magnetic force of the magnet 208. At this time, the magnetic force of the magnet 208 acts strongly in the axial direction, which is the direction of the arrow in FIG. 14 , and the axial lengths of the magnet 208 and the cylindrical body 209 (ferromagnetic body) are formed to be approximately the same. As a result, the magnet 208 is stably fixed by the magnetic force at approximately the same position as the cylindrical body 209 (ferromagnetic body) in the axial direction. At this time, the friction body 206 engaged with the second operating body 205 is inserted into the rear hole 244 of the first operating body 204, and the front end of the friction body 206 abuts against the bottom 245. The rear end of the second operating body 205 protrudes rearward from the rear end opening 225 of the barrel 202. Therefore, by pressing the second operating body 205 forward, the first operating body 204 can be pressed forward.

[0101] The retraction mechanism is a side-slide type mechanism using a rotary cam mechanism. The retraction mechanism includes a cam portion 226 formed on the inner surface of the rear barrel 223, a rotating member 207 that engages with the cam portion 226 and abuts against the rear end of the writing element 203, a first operating body 204 that engages with the rotating member 207 and protrudes radially outward from the slide hole 224, a second operating body 205 that protrudes rearward from a rear end opening 225 of the barrel 202, and a spring 211 (e.g., a compression coil spring) that is housed in the barrel 202 and biases the writing element 203 rearward. The retraction mechanism of this embodiment is a double-knock type in which the pen tip is extended and retracted by sliding the first operating body 204 forward or pressing the second operating body 205 forward.

[0102] When the second operating body 205 is pressed forward from the pen tip retracted state shown in FIG. 13 against the magnetic force of the magnet 208 and the rearward bias of the resilient body 211, the first operating body 204, which is in contact with the friction body 206, is pressed forward, and the first operating body 204 presses the rotating member 207 forward, which presses the rear end of the writing body 203 forward, causing the pen tip 231 to protrude forward and outward from the front end hole 227. At this time, the rotating member 207 engages with the cam portion 226, maintaining the pen tip protruding state as shown in FIG. 16. Then, the second operating body 205 is attracted to the cylindrical body (ferromagnetic body) by the magnetic force of the magnet 208 and retracts to the position it was in before being pressed, resulting in the state shown in FIG. 17. This puts the thermochromic writing instrument 201 into a usable state (a state ready for writing).

[0103] 17, when the second operating body 205 is pressed forward against the magnetic force of the magnet 208, the front end of the friction body 206 fixed to the advanced second operating body 205 comes into contact with the bottom of the first operating body 204, moving the first operating body 204 forward. The advanced first operating body 204 then advances the rotating member 207, disengaging the cam portion 226 from the rotating cam of the rotating member 207 and causing the rotating member 207 to move backward, which in turn moves the writing body 203, the first operating body 204, and the second operating body 205 backward, resulting in the pen-tip-retracted state. This places the thermochromic writing instrument 201 in an unused state (a writing-unused state and a friction body-unused state). Furthermore, when the writing body 203, the first operating body 204, and the second operating body 205 move backward, the second operating body 205 is attracted to the cylindrical body 209 (ferromagnetic body) by the magnetic force of the magnet 208, thereby stopping its backward movement. This reduces the impact force generated when the backward movement stops, and the first operating body 204 is received by the friction body 206 made of an elastic body fixed to the second operating body 205. This reduces the impact force applied to the writing body 203. This is particularly effective in a structure in which a ball is held in the pen tip of the writing body 203 as in this embodiment, because if the writing body 203 receives a strong impact when it moves backward, the ball will move backward, and air will be drawn in between the ball and the tip of the ballpoint pen, which may hinder the discharge of ink inside during writing.

[0104] The operation of extending and retracting the writing element 203 forward can also be performed by sliding only the first operating element 204 forward, without the need to operate the second operating element 205. This allows the user to extend the writing element by operating either the first operating element 204 or the second operating element 205, thereby transitioning from an unused state to a used state, which is highly convenient.

[0105] Next, a state in which the second operating body 205 is removed from the barrel 202 and then reattached to the barrel 202 will be described. In the thermochromic writing instrument 201 of this embodiment, from the state shown in Fig. 13, the second operating body 205 can be pulled out from the barrel 202 as shown in Fig. 18 by grasping the second operating body 205 and pulling it backward against the magnetic force acting between the magnet 208 and the cylindrical body 209 (ferromagnetic body). At this time, the friction body 206 is pulled out together with the second operating body 205 and exposed to the outside, so that the second operating body 205 serves as a gripping part and can be firmly gripped. By rubbing the writing with thermochromic ink on the writing instrument with the friction body 206, frictional heat is generated, causing the writing to discolor. Furthermore, when the removed second operating body 205 is brought closer to the mounting opening 210 of the barrel from the friction body 206, the magnetic force of the magnet 208 attracts the second operating body 205 into the barrel, and it is attracted to the original position shown in Figure 13.

[0106] Furthermore, in this embodiment, when reattaching the second operating body 205 to the barrel tube 202 after it has been pulled out as shown in Fig. 18 , the second operating body 205 can be attached to the barrel tube 202 even if the front-to-rear direction of the second operating body 205 is reversed. When the second operating body 205 is reversed and brought closer to the attachment opening 210 of the barrel tube 202 from the rear end side, the second operating body 205 is attracted to the tubular body 209 (ferromagnetic body) by the magnetic force of the magnet 208, just as when it is attached from the friction body 206 side, and the state shown in Fig. 19 is reached in which the second operating body 205 is attached to the barrel tube 202. In this state shown in Fig. 19 , the restricting portion 228 of the barrel tube and the rear part 256 of the second operating body 205 abut against each other, and the friction body 206 protrudes rearward from the rear end opening 225 of the barrel tube 202, and the second operating body 205 is attached to the barrel tube 202. 19, when rubbing handwriting with thermochromic ink with the friction body 206, the user can grasp the barrel 202 and perform the rubbing action. Because the barrel diameter of the barrel 202 is larger than that of the second operating body 205, it is easier to apply force than when rubbing by grasping the second operating body 205. This makes it easier to perform the rubbing action and thermally discolor the handwriting due to frictional heat. Note that in this embodiment, even when the second operating body 205 is attached backwards, the pen tip 231 of the writing body 203 can be extended and retracted by sliding the first operating body 204 along the axial direction, further improving convenience.

[0107] In this embodiment, the elastic material constituting the friction body 206 is preferably an elastic synthetic resin (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, and ethylene propylene diene rubber (EPDM). The elastic synthetic resin constituting the friction body 206 is not a highly abrasive elastic material (such as an eraser), but a low-abrasion elastic material that generates almost no abrasion debris (eraser debris) during friction. The friction body 206 may be provided at least on the outer surface of the front end of the second operating body 205. For example, the friction body 206 made of an elastic material may be secured (fixed) to the outer surface of the front end of the second operating body 205 by press-fitting, engaging, screwing, fitting, bonding, two-color molding, or the like. Alternatively, the entire second operating body 205, except for the magnet 208, may be integrally formed from an elastic material.

[0108] In this embodiment, the material constituting the cylindrical body 209 (ferromagnetic body) is one that is attracted by the magnetic force of the magnet 208, and it is preferable to use a substance that is strongly magnetized by a magnetic field and remains magnetized even when the magnetic field is removed, such as iron, cobalt, nickel and their alloys, ferrite, etc.

[0109] The knock-type writing instrument (thermochromic writing instrument) 201 of this embodiment can store the friction body 206 inside the barrel 202 when not needed, and can be easily removed from the barrel together with the second operating body 205, which is attracted by magnetic force, to perform the rubbing operation, making it highly convenient and preventing the friction body 206 from becoming dirty.

[0110] [1] The knock-type writing instrument (thermochromic writing instrument) 201 of this embodiment accommodates a writing body 203 inside a barrel 202 so as to be movable in the front-rear direction, accommodates thermochromic ink inside the writing body 203, provides a pen tip 231 capable of ejecting thermochromic ink at the front end of the writing body 203, protrudes a first operating body 204 movable in the front-rear direction from a side wall 229 of the barrel 202, and is configured so that the pen tip 231 of the writing body 203 can be protruded and retracted from the front end hole of the barrel 202 by sliding the first operating body 204 forward. The knock-type writing instrument (thermochromic writing instrument) 201 houses a friction body 206 made of a low-wear elastic material that can rub the handwriting of "K" and thermochromicize the handwriting with the frictional heat generated when the handwriting is rubbed, and is provided with a second operating body 205 at the rear of the writing body 203, at least a portion of which protrudes from the rear end of the barrel 202 and can operate the first operating body 204, and the second operating body 205 has the friction body 206 in its front portion and is attached to the barrel 202 so as to be slidable back and forth along the axial direction by magnetic force and to be detachably attached thereto.

[0111] According to such a knock-type writing instrument 201, the friction body 206 is provided at the front portion of the second operating body 205, and the friction body 206 is housed in the barrel 202. Therefore, regardless of whether the pen tip 231 is protruding or retracting, contact with the user's fingertip and contact between the friction body 206 and the inner surface of a container (for example, the inner surface of a pen case, the bottom surface of a pen stand, or the inner surface of a clothing pocket) can be avoided, and adhesion of fingerprints, dust, etc. to the friction body 206 (i.e., contamination of the friction body 206) can be prevented. Furthermore, since the second operating body 205 is removably attached to the barrel 202 by magnetic force, there is no need for a locking or press-fit structure for the barrel 202. Simply bringing the second operating body 205 close to the barrel 202 automatically attracts the second operating body 205 to the barrel 202 by magnetic force. Therefore, the second operating body 205 can be easily attached to and detached from the barrel 202. Furthermore, since the second operating body 205 is provided with the friction body 206 at the front portion thereof, the friction body 206 can be easily exposed to the outside by removing the second operating body 205 from the barrel 202, and the friction body 206 can be held firmly without being soiled with fingerprints or oils by gripping the operating body, which has the effect of making it easier to apply force when performing a rubbing action with the friction body 206 to thermally discolor the handwriting due to frictional heat.

[0112] Furthermore, in the knock-type writing instrument 201 of this embodiment, by operating the second operating body 205 protruding from the rear end of the barrel 202, the first operating body 204 can be indirectly operated and the pen tip 231 of the writing body 203 can be caused to protrude from the front end hole of the barrel 202.This means that the user can choose either the first operating body 204 protruding from the side wall 229 of the barrel 202 or the second operating body 205 protruding from the rear end of the barrel 202 to operate the writing body 203 to extend or retract, making it highly convenient.

[0113] In this embodiment, the elastic material constituting friction body 206 is preferably an elastic synthetic resin (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, ethylene propylene diene rubber (EPDM), etc. The elastic synthetic resin constituting friction body 2064 is not a highly abrasive elastic material (such as an eraser), but a low-abrasion elastic material that generates almost no abrasion debris (eraser debris) during friction.

[0114] [2] The knock-type writing instrument (thermochromic writing instrument) 201 of this embodiment is the knock-type writing instrument (thermochromic writing instrument) 201 described in [1], which has a magnet 208 on either the barrel 202 or the second operating body 205, and a ferromagnetic body 209 that is attracted to the magnet 208 on the other.

[0115] According to such a knock-type writing instrument 201, the ferromagnetic body 209 provided on either the barrel 202 or the second operating body 205 is attracted by a magnetic field generated by the magnet 208 provided on the other, so that the second operating body 205 can be attracted to the barrel 202 by magnetic force without using a press-fit or locking structure. When the second operating body 205 is attached to the barrel 202 by magnetic force, it is preferable to adjust the magnetic force, magnetic field, shapes, and distance between the magnet 208 and the ferromagnetic body 209 so that the axial position of the second operating body 205 relative to the barrel 202 is stable. This prevents the second operating body 205 from pressing the first operating body 204 forward when the second operating body 205 is attached to the barrel 202, thereby preventing the pen tip 231 from being accidentally extended.

[0116] In this embodiment, the ferromagnetic material 209 is a material that is attracted by the magnetic force of the magnet 208, is strongly magnetized by a magnetic field, and remains magnetized even after the magnetic field is removed. Examples of such materials include iron, cobalt, nickel, and alloys thereof, and ferrite.

[0117] Furthermore, the second operating body 205 may be configured to operate the first operating body 204, and when the distance between the magnet 208 and the ferromagnetic body 209 is maximized as the second operating body 205 moves forward, the operating body may be configured to return to its position before operation solely by the magnetic force acting between the magnet 208 and the ferromagnetic body 209. In this case, even if the second operating body 205 is moved forward by a pressing operation or the like, the second operating body 205 returns to its original position by the magnetic force, eliminating the need to bias the second operating body 205 with a compression spring such as a coil spring, thereby simplifying the configuration of the operating mechanism and reducing costs. Furthermore, because the second operating body 205 always returns to its original position even when the writing body 203 is extended, the second operating body 205 does not become immersed in the barrel 202 when removed from the barrel 202 to use the friction body 206, and therefore the second operating body 205 is not difficult to grip.

[0118] [3] The knock-type writing instrument (thermochromic writing instrument) 201 of this embodiment is the knock-type writing instrument (thermochromic writing instrument) 201 described in [1] or [2], in which, when the second operating body 205 is removed from the barrel 202, the second operating body 205 can be attached and detached to the barrel 202 by magnetic force even if the front-to-back direction of the second operating body 205 is reversed.

[0119] [4] The knock-type writing instrument (thermochromic writing instrument) 201 of this embodiment is a knock-type writing instrument (thermochromic writing instrument) 201 described in claim [3], in which, when the second operating body 205 is attached to the barrel 202 with the front and back reversed, at least a part of the friction body 206 engaged with the first operating body 204 protrudes outward from the barrel 202.

[0120] According to such a knock-type writing instrument 201, the friction body 206 engaged with the second operating body 205 is configured to protrude rearward from the rear end of the barrel 202, which prevents the second operating body 205 from being lost or damaged when removed, and also allows the barrel 202 to be gripped when thermally discoloring handwriting using the friction body 206, so that gripping the barrel 202, which is at least thicker than the second operating body 205, allows for a firm grip and makes it easier to apply force, which is preferable.

[0121] [5] The knock-type writing instrument (thermochromic writing instrument) 201 of this embodiment is a knock-type writing instrument (thermochromic writing instrument) 201 described in [3] or [4], in which, when the second operating body 205 is attached to the barrel 202 in an inverted position, the operating body abuts against a regulating portion 228 that regulates the forward movement of the operating body.

[0122] According to such a knock-type writing implement 201, even if force is applied to the friction body 206 when using it, the friction body 206 can be prevented from advancing and sinking into the barrel 202 together with the second operating body 205, so that more force can be applied to the friction body 206 when using it, making it easier to perform the rubbing action.

Claims

1. The pen comprises a barrel, a writing body housed inside the barrel and having a writing part at the tip, a feeding mechanism for feeding the writing body forward, and an operating body disposed behind the feeding mechanism for operating the feeding mechanism, a handwriting change member attached to the front of the operation body for removing, thermally discoloring, or concealing handwriting written with the writing tool; At least a portion of the operating body protrudes from the barrel, and the operating body is detachably attached to the barrel by a magnetic force acting between the barrel and the operating body; A knock-type writing instrument characterized in that after the operating body is pressed forward to activate the feeding mechanism, when the forward pressure on the operating body is released, the operating body moves backward due to the magnetic force acting between the barrel and the operating body, returning to the position before operation.

2. 2. The knock-type writing implement according to claim 1, wherein a magnet is provided in either the barrel or the operating body, and a ferromagnetic body is provided in the other of the barrel or operating body that is attracted by the magnetic force of the magnet.

3. The knock-type writing instrument according to claim 2, characterized in that the feeding mechanism is activated by operating the operating body, and when the distance between the magnet and the ferromagnetic body is maximized, the operating body returns to its position before operation solely by the magnetic force acting between the magnet and the ferromagnetic body.

4. A knock-type writing instrument as described in any one of claims 1 to 3, characterized in that when the operating body is removed from the barrel, it can be attached and detached freely to the barrel by magnetic force even if the front and rear directions of the operating body are reversed.

5. 5. The knock-type writing implement according to claim 4, wherein when the operating body is attached to the barrel in a reversed front-to-back position, the operating body abuts against a restricting portion that restricts forward movement of the operating body.

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