Notebook

Abstract

To ensure a sealed state of a storage space of a pen point sufficiently in a retracted state of the pen point.SOLUTION: A writing instrument 10 comprises a barrel 20 having a front end opening 20a, a writing member 12 having a pen point 13, a retractable mechanism 40 allowing the pen point 13 to be retractable from the front end opening 20a and a seal mechanism 70 for sealing a storage space S of the pen point 13 at the retracted state of the pen point 13. The seal mechanism 70 has a fixing member 72 fixed to the barrel 20 and a movement member 74 movable back and forth integrally with the writing member 12, and seals the storage space S by abutment of the fixing member 72 and the movement member 74 in an axis direction da.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a writing instrument. [Background technology]

[0002] Conventionally, there is known a writing instrument that includes a barrel, a writing element having a nib, and a retraction mechanism that causes the nib to protrude from and retract into the barrel. Among such writing instruments, there is also known a writing instrument that includes a sealing mechanism that seals the nib storage space when the nib is retracted to prevent ink from drying out in the nib.

[0003] Patent Document 1 discloses a retractable writing instrument that includes a barrel, a cartridge that is disposed within the barrel and has a tip at its tip, and an O-ring that is fitted around the outer periphery of the cartridge. In this retractable writing instrument, the O-ring tightly contacts the inner surface of the barrel, thereby maintaining an airtight internal space in the barrel between the tip opening of the barrel and the O-ring, and preventing the ink in the tip from drying out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-166500 Summary of the Invention [Problem to be solved by the invention]

[0005] In the retractable writing instrument disclosed in Patent Document 1, when the tip of the cartridge is extended or retracted, the barrel and the O-ring remain in radial contact with each other, and the O-ring slides back and forth relative to the barrel. In this case, friction between the barrel and the O-ring may cause the O-ring to wear or break. If a gap forms between the barrel and the O-ring due to wear or breakage of the O-ring, the internal space of the barrel between the tip opening of the barrel and the O-ring cannot be maintained in an airtight state. This can lead to the problem of ink drying out in the tip.

[0006] The present invention has been made in consideration of the above points, and aims to ensure that the storage space for the pen tip is sufficiently sealed when the pen tip is immersed. [Means for solving the problem]

[0007] The writing instrument according to the present invention comprises: A writing implement comprising: a barrel having a front end opening; a writing member having a pen tip; a retraction mechanism for retracting the pen tip from the front end opening; and a sealing mechanism for sealing an accommodation space for the pen tip when the pen tip is retracted, The sealing mechanism includes: a fixed member fixed to the barrel; a moving member that can move back and forth integrally with the writing member, The fixed member and the movable member abut against each other in the axial direction, thereby sealing the accommodation space.

[0008] In the writing instrument according to the present invention, A resilient member may be provided to bias the moving member rearward.

[0009] In the writing instrument according to the present invention, The resilient member may bias the writing member rearward via the moving member.

[0010] In the writing instrument according to the present invention, a cylindrical member surrounding at least a portion of the storage space; The moving member may abut against the cylindrical member.

[0011] In the writing instrument according to the present invention, The moving member may include a flow path that allows air to flow along the axial direction.

[0012] In the writing instrument according to the present invention, The flow path may include a notch formed in an outer circumferential surface of the moving member.

[0013] In the writing instrument according to the present invention, The flow path may include a through-hole that passes through the moving member.

[0014] In the writing instrument according to the present invention, When viewed in the axial direction, the entire flow path may overlap with the fixing member. [Effects of the Invention]

[0015] According to the present invention, when the pen tip is immersed, the storage space for the pen tip can be kept sufficiently sealed. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram for explaining one embodiment of the present invention, and is a vertical cross-sectional view showing an example of a writing implement in an immersed state. [Figure 2] FIG. 2 is an enlarged longitudinal cross-sectional view of the front portion of the writing implement of FIG. [Figure 3] FIG. 3 is a vertical cross-sectional view showing the writing implement in a protruding state. [Figure 4] 4 is an enlarged longitudinal cross-sectional view of the front portion of the writing implement of FIG. [Figure 5] FIG. 5 is a cross-sectional view showing an example of the cross-sectional shape of a moving member of a writing implement. [Figure 6] FIG. 6 is a cross-sectional view showing another example of the cross-sectional shape of the moving member. [Figure 7] FIG. 7 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. [Figure 8] FIG. 8 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. [Figure 9] FIG. 9 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. [Figure 10] FIG. 10 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. [Figure 11] FIG. 11 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will now be described with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

[0018] 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.

[0019] In this specification, the direction in which the central axis A of the writing instrument 10 extends (longitudinal direction) is referred to as the axial direction da, the direction perpendicular to the axial direction da is referred to as the radial direction, and the direction along the circumference around the central axis A is referred to as the circumferential direction dc. Along the axial direction da, the side toward the pen tip is referred to as the front, and the side opposite the pen tip is referred to as the rear. Also, along the radial direction, the side closer to the central axis A is referred to as the inside or inner side, and the side away from the central axis A is referred to as the outside or outer side.

[0020] Fig. 1 is a diagram for explaining one embodiment of the present invention, and is a vertical cross-sectional view showing an example of a writing instrument 10 in a immersed state, Fig. 2 is a vertical cross-sectional view showing an enlarged front portion of the writing instrument 10 in the immersed state, Fig. 3 is a vertical cross-sectional view showing the writing instrument 10 in a protruding state, and Fig. 4 is a vertical cross-sectional view showing an enlarged front portion of the writing instrument 10 in the protruding state.

[0021] The writing instrument 10 of this embodiment includes a writing member 12, a barrel 20, a retractable mechanism 40, and a sealing mechanism 70. The writing instrument 10 extends along a central axis A. The writing member 12 is a member that writes on a writing surface such as paper. The writing member 12 is housed within the barrel 20. Examples of the writing member 12 include components used in ballpoint pens, fountain pens, markers, etc. In this embodiment, an example will be described in which the writing instrument 10 is a fountain pen. The writing member 12 of this embodiment includes ink, a barrel that houses the ink, a nib 13 provided at the front end, a first receiving portion 14, and a protruding portion 15. The first receiving portion 14 is a forward-facing surface of a step formed on the outer surface of the writing member 12, and receives the elastic force of an elastic member 42 (described later) via a moving member 74 (described later). The protrusion 15 protrudes radially outward from the main body of the writing element 12 .

[0022] The retractable mechanism 40 is a mechanism for alternately switching the writing instrument 10 between a protruding state in which the nib 13 protrudes from the front end opening 20a of the barrel 20 and a retracted state in which the nib 13 is retracted from the front end opening 20a.

[0023] The barrel 20 includes a front barrel 21, a tip member 30 disposed in front of the front barrel 21, and a rear barrel 31 disposed behind the front barrel 21. The central axis of the barrel 20 coincides with the central axis A of the writing instrument 10. A front end opening 20a is provided at the front end of the barrel 20, through which the nib 13 can pass. In this embodiment, the front end opening 20a is formed at the front end of the tip member 30.

[0024] Front barrel 21 is a member having a generally cylindrical shape, and is intended to be grasped with the fingers of a user when writing with writing instrument 10. Front barrel 21 includes inner shaft 22, outer shaft 25 disposed radially outward of inner shaft 22, first connecting member 26, tubular member 27, and front sealing member 29.

[0025] The inner shaft 22 is a member that houses the front portion of the writing element 12. The inner shaft 22 is a member having a generally cylindrical shape. The inner surface of the inner shaft 22 includes a large diameter portion 22a and a small diameter portion 22b located in front of the large diameter portion 22a. The radial dimension of the small diameter portion 22b is smaller than the radial dimension of the large diameter portion 22a. In the immersed state, the large diameter portion 22a houses at least a portion of the main body of the writing element 12, and the small diameter portion 22b houses the nib 13. Because the radial dimension of the small diameter portion 22b that houses the nib 13 in the immersed state is smaller than the radial dimension of the large diameter portion 22a, the volume of the storage space S, which will be described later, is reduced. This reduces the amount of ink that evaporates from the nib 13 within the storage space S.

[0026] A step 23 is formed between the large diameter portion 22a and the small diameter portion 22b. A groove 24 that engages with the protrusion 15 of the writing member 12 is formed on the inner surface of the large diameter portion 22a. The groove 24 extends in the axial direction da, and the protrusion 15 of the writing member 12 is positioned within the groove 24, so that the writing member 12 is supported relative to the barrel 20 so as to be movable in the axial direction da but not rotatable in the circumferential direction. The inner shaft 22 is formed, for example, from resin.

[0027] Outer shaft 25 is a component visible to the user and is also a component that the user grasps with their fingers when writing with writing instrument 10. Therefore, outer shaft 25 is formed of an appropriate material, taking into consideration design and ease of grip by the user. For example, outer shaft 25 may be formed of resin, elastomer, metal, wood, or the like. First connecting member 26 is a component that forms a connection with rear shaft 31. First connecting member 26 is fixed to the rear end of at least one of inner shaft 22 and outer shaft 25. For example, first connecting member 26 may be fixed to the rear end of at least one of inner shaft 22 and outer shaft 25 by adhesive bonding. First connecting member 26 is formed of, for example, resin, metal, or the like. Note that the illustrated example is not limiting, and inner shaft 22 and outer shaft 25 may be formed of a single component. Furthermore, inner shaft 22, outer shaft 25, and first connecting member 26 may be formed of a single component. In other words, the entire front shaft 21 may be formed integrally.

[0028] The tubular member 27 and the front sealing member 29 are members that define the storage space S for the pen tip 13. The tubular member 27 is a member having a substantially cylindrical shape with a central axis that coincides with the central axis A. The tubular member 27 is fixed to the inner shaft 22. Specifically, the tubular member 27 is attached to the small-diameter portion 22b of the inner shaft 22. The tubular member 27 is attached to the inner shaft 22 by, for example, press-fitting, gluing, or screwing of a threaded portion. The material of the tubular member 27 is not particularly limited, and examples thereof include metal and resin. The front end of the front sealing member 29 is closed by the lid portion 17 (described below), thereby sealing the front end of the storage space S. The front sealing member 29 is attached to the front end of the tubular member 27. In particular, the front sealing member 29 is attached to the tubular member 27 so that the space between the front sealing member 29 and the tubular member 27 is sealed. The front sealing member 29 is formed of an elastic material such as rubber.

[0029] A lid portion 17 is attached to the cylindrical member 27. In the retracted state, the lid portion 17 closes the front end of the front sealing member 29 to seal the storage space S, and in the protruding state, the lid portion 17 allows the nib 13 to protrude. The lid portion 17 is biased by a resilient member 18 in a direction to seal the storage space for the nib 13. The resilient member 18 is, for example, a torsion spring. In this embodiment, in the retracted state, the resilient force of the resilient member 18 closes the lid portion 17, sealing the storage space S (see FIGS. 1 and 2). This prevents the ink on the nib 13 from drying out. When transitioning from the retracted state to the protruding state, the nib 13 moves forward and pushes the lid portion 17 forward, opening the lid portion 17, and the nib 13 protrudes forward from the front-end opening 20a of the barrel 20 (see FIGS. 3 and 4). In this protruding state, writing with the writing instrument 10 becomes possible.

[0030] Tip member 30 is a member that forms the tip portion of barrel 20. Tip member 30 has the function of protecting tubular member 27, front sealing member 29, lid portion 17, and resilient member 18. Tip member 30 has a generally truncated cone shape, and its outer diameter decreases toward the front. A front end opening 20a from which nib 13 appears and disappears is formed at the front end of tip member 30. The rear end of tip member 30 is attached to the front end of front barrel 21, thereby connecting tip member 30 to front barrel 21. Tip member 30 is connected to front barrel 21 by, for example, press-fitting, adhesive bonding, or threaded engagement of a threaded portion.

[0031] The rear axle 31 is a generally cylindrical member disposed rearward of the front axle 21. The rear axle 31 includes an inner shaft 32, an outer shaft 35 disposed radially outward of the inner shaft 32, a second connecting member 36, and a crown 38.

[0032] The inner shaft 32 is a member that houses the rear portion of the writing member 12. The inner shaft 32 is a member having a generally cylindrical shape. The inner shaft 32 is formed, for example, from resin, metal, wood, or the like. The inner peripheral surface of the inner shaft 32 is formed with a plurality of sawtooth-shaped cam teeth that protrude forward, and grooves that are formed between the cam teeth and extend in the axial direction da.

[0033] The outer shaft 35 is a member that is visible to the user. Therefore, the outer shaft 35 is formed of an appropriate material, taking into consideration design and the like. For example, the outer shaft 35 may be formed of resin, elastomer, metal, wood, or the like. The second connecting member 36 is a member that forms a connection with the front shaft 21. The second connecting member 36 is fixed to the front end of at least one of the inner shaft 32 and the outer shaft 35. For example, the second connecting member 36 may be fixed to the front end of at least one of the inner shaft 32 and the outer shaft 35 by adhesive bonding. The second connecting member 36 is formed of, for example, resin, metal, or the like. Note that the present invention is not limited to the illustrated example, and the inner shaft 32 and the outer shaft 35 may be formed of a single member. Furthermore, the inner shaft 32, the outer shaft 35, and the second connecting member 36 may be formed of a single member. In other words, the entire rear shaft 31 may be formed integrally.

[0034] The retractable mechanism 40 is a mechanism for alternately switching the writing instrument 10 between a protruding state and a retracted state. The retractable mechanism 40 of this embodiment includes a knock member 50, a rotating cam member 60, a first resilient member (resilient member) 42, and a second resilient member 44.

[0035] The first resilient member (resilient member) 42 is, for example, a coil spring. The first resilient member 42 is disposed in a compressed state between the first receiving portion 14 of the writing member 12 and the second receiving portion 28 of the barrel 20 (front barrel 21). In this embodiment, the first receiving portion 14 receives a resilient force from the first resilient member 42 via the moving member 74. As a result, the first resilient member 42 constantly biases the writing member 12 rearward relative to the barrel 20. The first resilient member 42 constitutes a part of the extending / retracting mechanism 40, and also constitutes a part of the sealing mechanism 70, as will be described later.

[0036] The knock member 50 is a member intended to be operated by the user. The knock member 50 includes an operating portion 52 and an expanded diameter portion 54 located in front of the operating portion 52. The operating portion 52 is the portion that is pressed by the user's finger or the like. The operating portion 52 protrudes rearward from the rear end of the barrel 20 (rear barrel 31). In the retracted state and the extended state, the rear end of the operating portion 52 protrudes rearward from the rear end of the barrel 20. The expanded diameter portion 54 has a radial dimension that is larger than the radial dimension of the operating portion 52. The inner diameter of the rear end of the barrel 20 is large enough that the operating portion 52 can pass through but the expanded diameter portion 54 cannot. Therefore, the knock member 50 will not slip out rearward from the rear end of the barrel 20.

[0037] Cam teeth that protrude forward are formed at the front end of the expanded diameter portion 54. In addition, a protrusion that engages with a groove formed in the inner peripheral surface of the barrel 20 (rear barrel 31) is formed on the outer peripheral surface of the expanded diameter portion 54. With the protrusion engaged with the groove of the barrel 20, the knock member 50 is arranged so as to be movable in the axial direction da but not rotatable in the circumferential direction.

[0038] A hole 56 extending in the axial direction da is formed inside the knock member 50. In this embodiment, the hole 56 is open at the front end of the knock member 50 and closed at the rear end of the knock member 50. An inward protrusion 58 that protrudes radially inward is formed on the inner surface of the hole 56.

[0039] The rotating cam member 60 has, on its outer surface, a plurality of ridges that extend in the axial direction da and engage with grooves in the barrel 20. Cam surfaces that are inclined with respect to the axial direction da and the circumferential direction are formed at the rear ends of the ridges. The cam surfaces engage with cam teeth of the knock member 50. The rotating cam member 60 has a rearward protruding portion 62 that protrudes rearward along the axial direction da. An engaging portion 64 is provided at the rear end of the rearward protruding portion 62. The engaging portion 64 is a protruding portion that protrudes radially outward from the rearward protruding portion 62. The engaging portion 64 engages with the inward protruding portion 58 of the knock member 50 to restrict movement of the knock member 50 and the rotating cam member 60 in the axial direction da.

[0040] A second resilient member 44 is disposed between the knock member 50 and the rotating cam member 60. The second resilient member 44 is, for example, a coil spring. The second resilient member 44 is disposed within the barrel 20 behind the writing member 12. Specifically, the second resilient member 44 is disposed in a compressed state between the knock member 50 and the rotating cam member 60. Therefore, the second resilient member 44 constantly biases the knock member 50 rearward relative to the rotating cam member 60. As a result, the knock member 50 moves rearward relative to the rotating cam member 60, but the engagement portion 64 of the rotating cam member 60 engages with the inward protrusion 58 of the knock member 50, preventing the knock member 50 from moving further rearward relative to the rotating cam member 60. When the engagement portion 64 of the rotating cam member 60 is engaged with the inward protrusion 58 of the knock member 50, the knock member 50 is forced rearward by the second spring member 44, thereby preventing the knock member 50 from rattling.

[0041] The specific structures and operations of the grooves of the barrel 20, the cam teeth and protrusions of the knock member 50, and the ridges and cam surfaces of the rotating cam member 60 are well known, so detailed explanations will be omitted. As an example, the specific structures of these may be the structure of the mechanism disclosed in JP 2013-006281 A.

[0042] The writing instrument 10 of this embodiment has a sealing mechanism 70 that seals the storage space S for the pen tip 13. This sealing mechanism 70 will be described below, mainly with reference to FIG. 2. The sealing mechanism 70 of this embodiment is a mechanism that seals the rear end of the storage space S. The sealing mechanism 70 includes a fixed member 72, a movable member 74, a first resilient member (resilient member) 42, and a second resilient member 44.

[0043] The fixed member 72 is a member fixed to the barrel 20 (front barrel 21). The fixed member 72 has an annular shape that surrounds the central axis A and extends in the circumferential direction dc. In particular, the fixed member 72 is disposed outside the writing member 12. The fixed member 72 is also disposed radially between the writing member 12 and the barrel 20. A gap is formed radially between the inner circumferential surface 73 of the fixed member 72 and the writing member 12. This gap serves as a flow path for air that flows out of the storage space S when the writing member 12 moves forward. In the example shown in FIG. 2, the fixed member 72 is fixed to the tubular member 27 of the barrel 20. The rear end of the tubular member 27 protrudes rearward from the step 23 of the inner shaft 22, and the fixed member 72 is fixed to this rear end. The fixed member 72 is attached to the tubular member 27 by, for example, adhesive bonding, press-fitting, or the like. The fixing member 72 may be made of an elastic material such as rubber.

[0044] The moving member 74 is a member disposed radially inward relative to the cylindrical member 27. The moving member 74 has an annular shape that surrounds the central axis A and extends in the circumferential direction dc. In this embodiment, the moving member 74 is disposed between the first resilient member 42 and the first receiving portion 14 of the writing member 12 in the axial direction da. Therefore, the moving member 74 is biased toward the first receiving portion 14 by the resilient force of the first resilient member 42. As a result, when the writing member 12 moves forward during the transition from the retracted state to the extended state, the moving member 74 receives a pressing force from the first receiving portion 14 and moves forward together with the writing member 12. Furthermore, when the writing member 12 moves backward during the transition from the extended state to the retracted state, the moving member 74 receives a resilient force from the first resilient member 42 and moves backward together with the writing member 12. That is, the moving member 74 can move back and forth together with the writing member 12 when transitioning from the retracted state to the protruding state, and when transitioning from the protruding state to the retracted state.

[0045] In the example shown in FIG. 2 , the moving member 74 abuts against the cylindrical member 27. In particular, the outer peripheral surface 75 of the moving member 74, located radially outward, abuts against the inner peripheral surface of the cylindrical member 27. The outer peripheral surface 75 of the moving member 74 may abut against the cylindrical member 27 over the entire circumference in the circumferential direction dc, or may abut against the cylindrical member 27 only partially over the entire circumference in the circumferential direction dc by providing a gap (described later). When the moving member 74 abuts against the cylindrical member 27, the moving member 74 moves back and forth while remaining in abutment against the cylindrical member 27. This generates friction between the moving member 74 and the cylindrical member 27. This reduces the moving speed of the moving member 74 relative to the cylindrical member 27. As described above, when the knock member 50 is pressed forward and then released in the protruding state, the writing member 12 moves rearward due to the resilient force of the first resilient member 42. At this time, the moving speed of the moving member 74 relative to the cylindrical member 27 decreases, so that the writing member 12 moves slowly backward after the user releases the pressure on the knock member 50. Therefore, the knock member 50 also moves slowly backward. This gives a sense of luxury to the extending and retracting movement of the writing instrument 10.

[0046] In the immersed state, the writing member 12 is urged forward via the rotating cam member 60 by the resilient force of the second resilient member 44. Therefore, in the immersed state, the first receiving portion 14 of the writing member 12 is in close contact with the moving member 74. In other words, the gap between the moving member 74 and the first receiving portion 14 is sealed.

[0047] The resilience of the first resilient member 42 is greater than the resilience of the second resilient member 44. When the movable member 74 is in contact with the cylindrical member 27, the resilience of the first resilient member 42 is greater than the sum of the frictional force generated between the movable member 74 and the cylindrical member 27 and the resilience of the second resilient member 44. As a result, in the immersed state, the movable member 74 is located at the rear end of its movable range in the axial direction da and abuts against the fixed member 72 from the front in the axial direction da. In particular, the movable member 74 is in close contact with the fixed member 72. That is, the gap between the movable member 74 and the fixed member 72 is sealed. Therefore, the rear end of the accommodation space S is sealed by the sealing mechanism 70.

[0048] In conventional retractable writing instruments, a sealing member such as an O-ring fits radially against a component such as the barrel, sealing the nib storage space. In such writing instruments, when the sealing member moves back and forth with the writing instrument, it slides against the component such as the barrel, which can cause the sealing member to wear or break. If a gap forms between the barrel and the sealing member due to wear or breakage of the sealing member, the storage space cannot be maintained in an airtight state. This can cause ink to dry out at the nib.

[0049] In contrast to this, in this embodiment, the fixed member 72 and the movable member 74 abut in the axial direction da, thereby sealing the storage space S for the pen tip 13. As a result, even if the movable member 74 is worn or damaged and a gap occurs between the cylindrical member 27 and the movable member 74, the fixed member 72 and the movable member 74 are in close contact in the axial direction da, so the storage space S can be kept sealed.

[0050] Furthermore, in the case of conventional technology, when a sealing member is fitted radially against a member such as the barrel to seal the storage space of the pen tip, if the sealing member is smaller than the specified dimensions, a gap will form between the sealing member and the member such as the barrel, making it impossible to properly seal the storage space. Furthermore, if the sealing member is larger than the specified dimensions, the frictional force generated between the sealing member and the member such as the barrel will be large, preventing the writing element from moving back and forth. Therefore, in this case, high dimensional accuracy is required for the sealing member, which increases the manufacturing cost of the part.

[0051] In contrast to this, in this embodiment, the movable member 74 is pressed against the fixed member 72 along the axial direction da by the elastic force of the first elastic member 42, so that the movable member 74 can be brought into appropriate close contact with the fixed member 72 even if the dimensional accuracy of the movable member 74 and the fixed member 72 is not high. This makes it possible to suppress an increase in the manufacturing cost of parts.

[0052] If the space between the writing member 12 and the tubular member 27 is completely sealed by the movable member 74, when the writing member 12 moves forward from the retracted state, the volume of the space sealed by the lid portion 17 and the movable member 74 decreases, and the pressure in this space increases. In this case, the increased pressure may generate a force pushing the writing member 12 backward. As a result, the user may need to apply a large amount of pressure to the knock member 50 to transition the writing instrument 10 from the retracted state to the extended state. Furthermore, if the lid portion 17 is opened while the pressure in the space sealed by the lid portion 17 and the movable member 74 is elevated, the pressure in the space suddenly decreases the moment the lid portion 17 opens. This sudden decrease in pressure may cause ink to leak from the nib 13. As described below, this increased pressure may also serve as an auxiliary force to open the lid portion 17 when the nib 13 pushes the lid portion 17 forward. Therefore, a configuration in which the space between the writing member 12 and the cylindrical member 27 is completely sealed by the moving member 74 is not excluded from the preferred embodiment.

[0053] In this embodiment, the moving member 74 includes a flow path 76 that allows air to flow along the axial direction da. As a result, when the writing member 12 moves forward from the immersed state and the moving member 74 separates from the fixed member 72, the space between the lid portion 17 and the moving member 74 and the space behind the moving member 74 are connected via the flow path 76. Therefore, even if the volume of the space between the lid portion 17 and the moving member 74 decreases, the pressure in this space does not change. This allows the user to press the knock member 50 forward without experiencing a force pushing the writing member 12 backward due to the pressure in this space. Furthermore, since the pressure in the space between the lid portion 17 and the moving member 74 does not suddenly decrease when the lid portion 17 is opened, ink leakage from the pen tip 13 can be suppressed.

[0054] Specific examples of the shape of such flow path 76 will be described below with reference to Figures 5 to 11. Figures 5 to 11 are cross-sectional views corresponding to line AA in Figure 2, showing a cross section perpendicular to the central axis A of the movable member 74. In Figures 5 to 11, the inner circumferential surface 73 of the fixed member 72 as viewed along the axial direction da is shown by a dashed line. Also, in Figures 5 to 11, the writing member 12 is not shown.

[0055] The flow path 76 may include a notch 77 formed in the outer peripheral surface 75 of the moving member 74 and extending in the axial direction da. In the example shown in FIGS. 5 to 8, the moving member 74 has the notch 77 formed in the circular outer peripheral surface 75. In particular, in the example shown, the moving member 74 has a plurality of notches 77 arranged in the circumferential direction dc. In this embodiment, the notch 77 extends parallel to the axial direction da, but this is not limited thereto. The notch 77 may extend in a direction inclined with respect to the axial direction da. In the example shown in FIG. 5, the notch 77 has a linear shape when viewed from the axial direction da. In the example shown in FIG. 6, the notch 77 has a shape with a constant depth. The depth here is a dimension measured radially inward from an extension line of the outer peripheral surface 75. In the example shown in FIG. 7, the notch 77 has an arc shape that convex radially inward. In the example shown in Fig. 8, the notch portions 77 have a shape formed by combining two arcs that are convex radially outward. Note that in the example shown in Fig. 5, the moving member 74 has four notch portions 77, in the example shown in Fig. 6, the moving member 74 has six notch portions 77, in the example shown in Fig. 7, the moving member 74 has eight notch portions 77, and in the example shown in Fig. 8, the moving member 74 has twelve notch portions 77, but the number of notch portions 77 is arbitrary and is not limited to these.

[0056] The flow path 76 may include through holes 78 that penetrate the moving member 74. In the example shown in FIGS. 9 and 10 , the moving member 74 has through holes 78 extending along the axial direction da. In particular, in the illustrated example, the moving member 74 has a plurality of through holes 78 aligned in the circumferential direction dc. In the present embodiment, the through holes 78 extend parallel to the axial direction da, but this is not limited thereto. The through holes 78 may extend in a direction inclined with respect to the axial direction da. In the example shown in FIG. 9 , the through holes 78 have a circular shape when viewed from the axial direction da. In the example shown in FIG. 10 , the through holes 78 have an oval shape extending along the circumferential direction dc. Note that in the example shown in FIG. 9 , the moving member 74 has 16 through holes 78, and in the example shown in FIG. 10 , the moving member 74 has three through holes 78, but the number of through holes 78 is arbitrary and is not limited thereto. Note that the flow path 76 may include both the cutout portions 77 and the through holes 78.

[0057] The moving member 74 does not have to be in contact with the cylindrical member 27. In the example shown in Fig. 11, a gap is formed between an outer peripheral surface 75 of the moving member 74 and the inner peripheral surface of the cylindrical member 27 over the entire circumference of the outer peripheral surface 75, and this gap forms a flow path 76.

[0058] 5 to 11, when viewed from the axial direction da, the entire flow path 76 is located radially outward of the inner circumferential surface of the fixed member 72. In other words, when viewed from the axial direction da, the entire flow path 76 overlaps with the fixed member 72. In this case, when the moving member 74 comes into close contact with the fixed member 72 in the axial direction da, the entire flow path 76 is blocked by the fixed member 72. This ensures that the rear end of the accommodation space S is properly sealed in the retracted state.

[0059] Next, the operations of the retractable mechanism 40 and the sealing mechanism 70 will be described with reference to FIGS.

[0060] When the user presses the knock member 50 forward in the immersed state (FIGS. 1 and 2), the writing member 12 moves forward via the rotating cam member 60. At this time, the moving member 74 also moves forward integrally with the writing member 12. When the moving member 74 separates from the fixed member 72, the space between the lid portion 17 and the moving member 74 and the space behind the moving member 74 communicate with each other via the flow path 76 and the gap formed between the inner circumferential surface 73 of the fixed member 72 and the writing member 12. When the writing member 12 moves further forward, the nib 13 pushes the lid portion 17 forward against the resilient force of the resilient member 18, thereby opening the lid portion 17. At this time, because the space between the lid portion 17 and the moving member 74 and the space behind the moving member 74 are connected, the user can press the knock member 50 forward without being subjected to a force pushing the writing member 12 backward due to pressure within this space. Furthermore, when the cover 17 is opened, the pressure in the space between the cover 17 and the moving member 74 does not suddenly decrease, which prevents ink from leaking from the pen tip 13. Furthermore, when the writing member 12 moves forward, the pen tip 13 protrudes forward from the front end opening 20a. Even when the forward pressure of the knock member 50 is released, the writing member 12 maintains a state in which the pen tip 13 protrudes forward from the front end opening 20a. This causes the writing instrument 10 to transition from the immersed state to the protruding state.

[0061] Furthermore, when the user presses the knock member 50 forward in the extended state (FIGS. 3 and 4), the writing member 12 moves a small distance forward. When the forward pressure on the knock member 50 is released, the resilient force of the first resilient member 42 moves the writing member 12 rearward, and the nib 13 retracts from the front-end opening 20a. As the writing member 12 moves further rearward, the nib 13 is housed within the storage space S, and the resilient force of the resilient member 18 causes the lid portion 17 to close the front end of the front sealing member 29. As the writing member 12 moves further rearward, the moving member 74 comes into close contact with the fixed member 72 in the axial direction da. At this time, the fixed member 72 completely blocks the flow path 76, sealing the storage space S. By sealing the storage space S, drying of the ink on the nib 13 is suppressed in the retracted state.

[0062] If the moving member 74 does not have a flow path 76, when the writing member 12 moves forward from the immersed state, the volume of the space sealed by the lid portion 17 and the moving member 74 decreases, and the pressure in this space increases. In this case, the increased pressure causes the lid portion 17 to receive a force acting in a direction that causes the lid portion 17 to open. Therefore, when the pen tip 13 pushes the lid portion 17 forward, this increased pressure serves as an auxiliary force for opening the lid portion 17. Therefore, a configuration in which the moving member 74 does not have a flow path 76 is also a preferred embodiment.

[0063] The writing instrument 10 of this embodiment comprises a barrel 20 having a front end opening 20a, a writing member 12 having a nib 13, a retraction mechanism 40 that causes the nib 13 to protrude and retract from the front end opening 20a, and a sealing mechanism 70 that seals the storage space S for the nib 13 when the nib 13 is retracted.The sealing mechanism 70 has a fixed member 72 fixed to the barrel 20 and a movable member 74 that can move back and forth integrally with the writing member 12, and the fixed member 72 and the movable member 74 abut in the axial direction da to seal the storage space S.

[0064] With this writing instrument 10, the fixed member 72 and the movable member 74 abut against each other in the axial direction da, thereby sealing the storage space S for the pen tip 13. As a result, even if the movable member 74 wears or breaks, causing a gap to form between the cylindrical member 27 and the movable member 74, the fixed member 72 and the movable member 74 are in close contact in the axial direction da, so the storage space S can be kept sealed. Therefore, the storage space S can be kept sealed sufficiently in the immersed state.

[0065] The writing instrument 10 of this embodiment has a resilient member 42 that biases the moving member 74 rearward.

[0066] According to this writing instrument 10, the elastic force of the elastic member 42 presses the movable member 74 against the fixed member 72 along the axial direction da, so that the movable member 74 can be brought into appropriate close contact with the fixed member 72 even if the dimensional accuracy of the movable member 74 and the fixed member 72 is not high. This makes it possible to prevent an increase in the manufacturing costs of parts.

[0067] In the writing instrument 10 of this embodiment, the resilient member 42 biases the writing member 12 rearward via the moving member 74.

[0068] In this writing instrument 10, the resilient member 42 functions to urge both the moving member 74 rearward and the writing member 12 rearward. In other words, the single resilient member 42 can urge both the moving member 74 rearward and the writing member 12 rearward. This prevents an increase in the number of parts.

[0069] The writing instrument 10 of this embodiment has a cylindrical member 27 that surrounds at least a portion of the storage space S, and the moving member 74 abuts against the cylindrical member 27.

[0070] With this writing instrument 10, friction occurs between the moving member 74 and the tubular member 27. This reduces the moving speed of the moving member 74 relative to the tubular member 27. As a result, when transitioning from the extended state to the retracted state, the knock member 50 moves slowly backward together with the writing member 12. This gives a luxurious feel to the extending and retracting movement of the writing instrument 10.

[0071] In the writing instrument 10 of this embodiment, the moving member 74 includes a flow path 76 that allows air to flow along the axial direction da.

[0072] In the writing instrument 10 of this embodiment, the flow path 76 includes a notch 77 formed in the outer peripheral surface of the moving member 74 .

[0073] In the writing instrument 10 of this embodiment, the flow path 76 includes a through-hole 78 that passes through the moving member 74 .

[0074] With this writing instrument 10, when the writing member 12 moves forward from the immersed state and the moving member 74 separates from the fixed member 72, the space between the lid portion 17 and the moving member 74 and the space behind the moving member 74 are connected via the flow path 76. Therefore, even if the volume of the space between the lid portion 17 and the moving member 74 decreases, the pressure in this space does not change. This allows the user to press the knock member 50 forward without being subjected to a force pushing the writing member 12 backward due to the pressure in this space. Furthermore, when the lid portion 17 is opened, the pressure in the space between the lid portion 17 and the moving member 74 does not suddenly decrease, which prevents ink from leaking from the pen tip 13.

[0075] In the writing instrument 10 of this embodiment, the entire flow path 76 and the fixed member 72 overlap when viewed in the axial direction da.

[0076] According to this writing instrument 10, when the movable member 74 is in close contact with the fixed member 72 in the axial direction da, the entire flow path 76 is blocked by the fixed member 72. This allows the rear end of the storage space S to be properly sealed in the immersed state. [Explanation of symbols]

[0077] 10 Writing instruments 12 Writing materials 13 Pen tip 14 First Receiving Section 15 Protrusion 17 Lid 18 Elastic member 20 shaft cylinder 20a Front end opening 21 Front axle 22 Inner shaft 22a Large diameter section 22b Small diameter section 23 Step section 24 Groove 25 Outer shaft 26 First connecting member 27 Cylindrical member 28 Second Receiving Section 29 Front sealing member 30 Tip member 31 rear axle 32 Inner shaft 35 Outer shaft 36 Second connecting member 38 Head crown 40 Appearance mechanism 42 First spring element (spring element) 44 Second spring element 50 Knock member 52 Operation section 54 Expanded diameter part 56 Hole 58 Inward protrusion 60 Rotating cam member 62 Rear protrusion 64 Engagement part 70 Sealing mechanism 72 Fixing member 73 Inner peripheral surface 74 Moving parts 75 Outer surface 76 Flow path 77 Notch 78 Through Hole da axial direction dc circumferential direction A Center axis S Storage space

Claims

1. A writing implement comprising: a barrel having a front end opening; a writing member having a pen tip; a retraction mechanism for causing the pen tip to protrude and retract from the front end opening; a sealing mechanism for sealing an accommodation space for the pen tip when the pen tip is retracted; and a cylindrical member surrounding at least a portion of the accommodation space, The sealing mechanism includes: a fixed member fixed to the barrel; a moving member that can move back and forth integrally with the writing member, the moving member is in contact with the cylindrical member, The fixed member and the movable member abut against each other in the axial direction, thereby sealing the accommodation space.

2. A writing instrument comprising: a barrel having a front end opening; a writing member having a pen tip; a retractable mechanism for causing the pen tip to protrude and retract from the front end opening; and a sealing mechanism for sealing the storage space for the pen tip when the pen tip is retracted, The sealing mechanism includes: a fixed member fixed to the barrel; a moving member that can move back and forth integrally with the writing member, the moving member includes a flow path that allows air to flow in an axial direction; The fixed member and the movable member abut in the axial direction, thereby sealing the accommodation space.

3. 3. The writing implement according to claim 1, further comprising a resilient member that biases the moving member rearward.

4. The writing implement according to claim 3 , wherein the resilient member biases the writing member rearward via the moving member.

5. The writing implement according to claim 2 , wherein the flow path includes a notch formed in an outer peripheral surface of the moving member.

6. The writing implement according to claim 2 or 5, wherein the flow path includes a through-hole that penetrates the moving member.

7. The writing implement according to claim 2 , wherein the entire flow path overlaps with the fixing member when viewed in the axial direction.

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