JP2023095594A - writing instrument - Google Patents

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

The present invention relates to writing instruments.

2. Description of the Related Art Conventionally, a writing instrument is known that includes a barrel, a writing member having a pen tip, and a retracting mechanism for retracting the pen tip from the barrel. Among such writing instruments, there is also known a writing instrument having a sealing mechanism that seals a space for accommodating the pen tip in order to prevent ink from drying at the pen tip when the pen tip is retracted.

Patent Literature 1 discloses a retractable writing instrument that includes a barrel, a cartridge that is disposed in the barrel and has a tip at the tip, and an O-ring fitted around the outer periphery of the cartridge. In this retractable writing instrument, the O-ring is in close contact with the inner surface of the barrel, so that the inner space of the barrel between the tip opening of the barrel and the O-ring is maintained in an airtight state, and the ink on the tip is prevented from drying. be done.

Japanese Patent Application Laid-Open No. 2009-166500

In the retractable writing instrument disclosed in Patent Document 1, when retracting the tip of the cartridge, the O-ring slides in the longitudinal direction with respect to the barrel while the barrel and the O-ring are in contact with each other in the radial direction. do. In this case, the O-ring may be worn or damaged due to friction between the barrel and the O-ring. If a gap occurs 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. As a result, there is a problem that the ink dries on the tip.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above points, and it is an object of the present invention to ensure a sufficiently sealed state of a space for accommodating a pen tip when the pen tip is retracted.

A writing instrument according to the present invention comprises:
A barrel having a front end opening, a writing member having a pen tip, a retracting mechanism for retracting the pen tip from the front opening, and a sealing mechanism for sealing the pen tip storage space when the pen tip is retracted. and a writing instrument comprising
The sealing mechanism is
a fixing member fixed to the barrel;
a moving member that can move back and forth integrally with the writing member,
The accommodation space is sealed by the axial contact between the fixed member and the movable member.

In the writing instrument according to the present invention,
It may have an elastic member that biases the moving member rearward.

In the writing instrument according to the present invention,
The elastic member may urge the writing member rearward via the moving member.

In the writing instrument according to the present invention,
Having a tubular member surrounding at least part of the accommodation space,
The moving member may abut against the tubular member.

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

In the writing instrument according to the present invention,
The flow path may include a notch formed on the outer peripheral surface of the moving member.

In the writing instrument according to the present invention,
The channel may include a through-hole passing through the moving member.

In the writing instrument according to the present invention,
When viewed from the axial direction, the entire channel and the fixing member may overlap.

According to the present invention, when the pen tip is retracted, it is possible to sufficiently ensure the sealed state of the space for accommodating the pen tip.

FIG. 1 is a diagram for explaining an embodiment of the present invention, and is a vertical cross-sectional view showing an example of a writing instrument in an immersed state. 2 is a longitudinal sectional view showing an enlarged front portion of the writing instrument of FIG. 1. FIG. FIG. 3 is a vertical cross-sectional view showing the writing instrument in a protruded state. 4 is a longitudinal sectional view showing an enlarged front portion of the writing instrument of FIG. 3. FIG. FIG. 5 is a cross-sectional view showing an example of the cross-sectional shape of the moving member of the writing instrument. FIG. 6 is a cross-sectional view showing another example of the cross-sectional shape of the moving member. FIG. 7 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. FIG. 8 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. FIG. 9 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. FIG. 10 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member. FIG. 11 is a cross-sectional view showing still another example of the cross-sectional shape of the moving member.

An embodiment of the present invention will be described below with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and ease of understanding, the scale, length-to-width ratio, etc. are appropriately changed and exaggerated from those of the real thing.

In addition, terms such as "parallel", "perpendicular", "identical", length and angle values, etc. that specify shapes and geometric conditions and their degrees used in this specification are strictly It shall be interpreted to include the extent to which similar functions can be expected without being bound by the meaning.

In this specification, the direction (longitudinal direction) in which the central axis A of the writing instrument 10 extends is the axial direction da, the direction orthogonal to the axial direction da is the radial direction, and the direction along the circumference around the central axis A is the circumferential direction dc. do. Along the axial direction da, the pen tip side is the front side, and the side opposite to the pen tip side is the rear side. In addition, along the radial direction, the side closer to the central axis A is the inner side or the inner side, and the side farther from the central axis A is the outer side or the outer side.

FIG. 1 is a diagram for explaining an embodiment of the present invention, and is a longitudinal sectional view showing an example of a writing instrument 10 in an immersed state, and FIG. 2 is an enlarged front portion of the writing instrument 10 in the immersed state. It is a vertical cross-sectional view shown in FIG. 3 is a longitudinal sectional view showing the writing instrument 10 in a protruding state, and FIG. 4 is a longitudinal sectional view showing an enlarged front portion of the writing instrument 10 in the protruding state.

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 the central axis A. As shown in FIG. The writing member 12 is a member that forms handwriting on a writing surface such as a paper surface. The writing member 12 is housed within the barrel 20 . Examples of the writing member 12 include members used for ballpoint pens, fountain pens, markers, and the like. In this embodiment, an example in which the writing instrument 10 is a fountain pen will be described. The writing member 12 of this embodiment has ink, a storage cylinder that stores the ink, a pen point 13 provided at the front end, a first receiving portion 14 and a projecting portion 15 . The first receiving portion 14 is a front facing surface of a stepped portion formed on the outer surface of the writing member 12, and receives the elastic force of an elastic member 42, which will be described later, via a moving member 74, which will be described later. The protruding portion 15 protrudes radially outward from the body portion of the writing member 12 .

The retraction mechanism 40 alternately switches the writing instrument 10 between a protruding state in which the pen tip 13 protrudes from the front end opening 20a of the barrel 20 and a recessed state in which the pen tip 13 retracts from the front end opening 20a. is.

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

The front barrel 21 is a member having a substantially cylindrical shape, and is intended to be grasped with fingers when the user writes with the writing instrument 10 . The front shaft 21 includes an inner shaft 22 , an outer shaft 25 arranged radially outwardly of the inner shaft 22 , a first connecting member 26 , a tubular member 27 and a front sealing member 29 . there is

The inner shaft 22 is a member that accommodates the front portion of the writing member 12 . The inner shaft 22 is a member having a substantially 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 accommodates at least a portion of the body portion of the writing member 12, and the small-diameter portion 22b accommodates the pen tip 13. As shown in FIG. Since the radial dimension of the small-diameter portion 22b that accommodates the pen tip 13 in the retracted state is smaller than the radial dimension of the large-diameter portion 22a, the capacity of an accommodation space S, which will be described later, is reduced. As a result, the amount of ink evaporated from the pen tip 13 in the housing space S can be reduced.

A step portion 23 is formed between the large diameter portion 22a and the small diameter portion 22b. A groove portion 24 that engages with the protruding portion 15 of the writing member 12 is formed on the inner surface of the large diameter portion 22a. The groove portion 24 is a groove extending in the axial direction da, and the protrusion portion 15 of the writing member 12 is positioned in the groove portion 24, so that the writing member 12 can move in the axial direction da and in the circumferential direction with respect to the barrel 20. is non-rotatably supported on the The inner shaft 22 is made of resin, for example.

The outer shaft 25 is a member that is visually recognized by the user and is a member that the user grips with his or her fingers when writing with the writing instrument 10 . Therefore, the outer shaft 25 is made of an appropriate material in consideration of the design and ease of holding by the user. For example, the outer shaft 25 may be made of resin, elastomer, metal, wood, or the like. The first connecting member 26 is a member forming a connecting portion with the rear axle 31 . The first connecting member 26 is fixed to the rear end of at least one of the inner shaft 22 and the outer shaft 25 . For example, the first connecting member 26 may be fixed to the rear end of at least one of the inner shaft 22 and the outer shaft 25 by adhesion. The first connecting member 26 is made of resin, metal, or the like, for example. In addition, the inner shaft 22 and the outer shaft 25 may be configured by a single member without being limited to the illustrated example. Alternatively, the inner shaft 22, the outer shaft 25 and the first connecting member 26 may be configured as a single member. That is, the entire front shaft 21 may be integrally formed.

The cylindrical member 27 and the front sealing member 29 are members that define the accommodation space S for the pen tip 13 . The tubular member 27 is a member having a substantially cylindrical shape with a central axis line that coincides with the central axis line A. As shown in FIG. The tubular member 27 is fixed with respect to the inner shaft 22 . Specifically, the tubular member 27 is attached to the small diameter portion 22b of the inner shaft 22 . The cylindrical member 27 is attached to the inner shaft 22 by, for example, press-fitting, adhesion, or threaded engagement. Although the material of the cylindrical member 27 is not particularly limited, for example, metal, resin, or the like can be used. The front sealing member 29 is a member for sealing the front end portion of the accommodation space S by closing the front end thereof with a lid portion 17 which will be described later. A front sealing member 29 is attached to the front end of the tubular member 27 . In particular, the front closure member 29 is attached to the tubular member 27 such that there is a seal between the front closure member 29 and the tubular member 27 . The front sealing member 29 is made of, for example, an elastic member such as rubber.

The lid portion 17 is attached to the tubular member 27 . The lid portion 17 closes the front end of the front sealing member 29 to seal the housing space S in the retracted state, and allows the pen tip 13 to protrude in the protruded state. The lid portion 17 is urged by an elastic member 18 in a direction to seal the accommodation space of the pen tip 13 . The resilient member 18 is, for example, a torsion spring. In this embodiment, in the retracted state, the lid portion 17 is closed by the elastic force of the elastic member 18, and the accommodation space S is sealed (see FIGS. 1 and 2). As a result, drying of the ink on the nib 13 is suppressed. When transitioning from the retracted state to the protruding state, the pen tip 13 moved forward pushes the lid portion 17 forward to open the lid portion 17, and the pen tip 13 moves forward from the front end opening portion 20a of the barrel 20. protrude (see FIGS. 3 and 4). In this projecting state, writing with the writing implement 10 is possible.

The tip member 30 is a member that forms the tip portion of the barrel 20 . The tip member 30 has a function of protecting the tubular member 27 , the front sealing member 29 , the lid portion 17 and the resilient member 18 . The tip member 30 has a substantially truncated cone shape, and its outer diameter decreases toward the front. The front end of the tip member 30 is formed with a front end opening 20a through which the pen tip 13 protrudes and retracts. The tip member 30 is connected to the front shaft 21 by attaching the rear end portion of the tip member 30 to the front end portion of the front shaft 21 . The tip member 30 is connected to the front shaft 21 by, for example, press fitting, adhesion, or threaded engagement.

The rear shaft 31 is a member having a substantially cylindrical shape and arranged behind the front shaft 21 . The rear shaft 31 includes an inner shaft 32 , an outer shaft 35 arranged radially outwardly of the inner shaft 32 , a second connecting member 36 , and a crown 38 .

The inner shaft 32 is a member that accommodates the rear portion of the writing member 12 . The inner shaft 32 is a member having a substantially cylindrical shape. The inner shaft 32 is made of resin, metal, wood, or the like, for example. The inner peripheral surface of the inner shaft 32 is formed with a plurality of saw-toothed cam teeth projecting forward, and grooves formed between the cam teeth and extending in the axial direction da.

The outer shaft 35 is a member visually recognized by the user. Therefore, the outer shaft 35 is made of an appropriate material in consideration of design and the like. For example, the outer shaft 35 may be made of resin, elastomer, metal, wood, or the like. The second connecting member 36 is a member forming a connecting portion 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 ends of at least one of the inner shaft 32 and the outer shaft 35 by adhesion. The second connecting member 36 is made of resin, metal, or the like, for example. In addition, the inner shaft 32 and the outer shaft 35 may be composed of a single member without being limited to the illustrated example. Alternatively, the inner shaft 32, the outer shaft 35 and the second connecting member 36 may be configured as a single member. That is, the entire rear axle 31 may be integrally formed.

The protruding/retracting mechanism 40 is a mechanism for alternately switching the writing instrument 10 between a protruded state and a retracted state. The retraction mechanism 40 of the present embodiment includes a knock member 50 , a rotating cam member 60 , a first elastic member (elastic member) 42 and a second elastic member 44 .

The first elastic member (elastic member) 42 is, for example, a coil spring. The first elastic member 42 is arranged 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 elastic force from the first elastic member 42 via the moving member 74 . As a result, the first elastic member 42 constantly urges the writing member 12 toward the rear with respect to the barrel 20 . In addition, the first resilient member 42 constitutes a part of the retraction mechanism 40 and also constitutes a part of the sealing mechanism 70 as will be described later.

Knock member 50 is a member intended to be operated by a user. The knock member 50 includes an operating portion 52 and an enlarged diameter portion 54 located in front of the operating portion 52 . The operating portion 52 is a portion that is pressed by a user's finger or the like. The operating portion 52 protrudes rearward from the rear end of the barrel 20 (rear shaft 31). The rear end of the operating portion 52 projects rearward from the rear end of the barrel 20 in the retracted state and the projected state. The enlarged diameter portion 54 has a radial dimension larger than the radial dimension of the operating portion 52 . The inner diameter of the rear end portion of the barrel 20 is large enough to allow the operation portion 52 to pass through but not to allow the enlarged diameter portion 54 to pass therethrough. Therefore, the knock member 50 does not come out rearward from the rear end portion of the barrel 20 .

A cam tooth projecting forward is formed at the front end of the enlarged diameter portion 54 . A protruding portion that engages with a groove formed in the inner peripheral surface of the barrel 20 (rear shaft 31) is formed on the outer peripheral surface of the enlarged diameter portion 54. As shown in FIG. The knock member 50 is arranged so as to be movable in the axial direction da and unrotatable in the circumferential direction, with the projecting portion engaged with the groove portion of the barrel 20 .

A hole portion 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 inner protruding portion 58 that protrudes radially inward is formed on the inner surface of the hole portion 56 .

The rotary cam member 60 has, on its outer surface, a plurality of ridges that extend in the axial direction da and engage with the grooves of the shaft cylinder 20 . A cam surface inclined with respect to the axial direction da and the circumferential direction is formed at the rear end of the ridge. The cam surface engages cam teeth on the knock member 50 . The rotating cam member 60 has a rear projection 62 that projects rearward along the axial direction da. An engaging portion 64 is provided at the rear end of the rear projection portion 62 . The engaging portion 64 is a protrusion that protrudes radially outward from the rear protrusion 62 . The engaging portion 64 engages with the inward projecting 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.

A second elastic member 44 is arranged between the knock member 50 and the rotary cam member 60 . The second elastic member 44 is, for example, a coil spring. The second elastic member 44 is arranged inside the barrel 20 behind the writing member 12 . Specifically, the second elastic member 44 is arranged in a compressed state between the knock member 50 and the rotating cam member 60 . Therefore, the second elastic member 44 always urges the knock member 50 rearward against the rotating cam member 60 . As a result, the knocking member 50 moves rearward with respect to the rotating cam member 60 , but the engaging portion 64 of the rotating cam member 60 engages the inward projecting portion 58 of the knocking member 50 , thereby causing the knocking member 50 to move backward. is prevented from moving further rearwardly relative to the rotating cam member 60 . With the engaging portion 64 of the rotating cam member 60 engaged with the inward projecting portion 58 of the knock member 50 , the knock member 50 is urged rearward by the second elastic member 44 , thereby causing the knock member 50 to move. Rattling is suppressed.

Since 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 rotary cam member 60 are known, detailed description thereof will be omitted. As an example, it is possible to use the structure of the mechanism disclosed in Japanese Unexamined Patent Application Publication No. 2013-006281 as these specific structures.

The writing instrument 10 of this embodiment has a sealing mechanism 70 that seals the accommodation space S of the pen tip 13 . The sealing mechanism 70 will be described below mainly with reference to FIG. The sealing mechanism 70 of this embodiment is a mechanism that seals the rear end of the accommodation space S. As shown in FIG. The sealing mechanism 70 includes a fixed member 72 , a moving member 74 , a first elastic member (elastic member) 42 and a second elastic member 44 .

The fixed member 72 is a member fixed to the barrel 20 (front shaft 21). The fixing member 72 has an annular shape surrounding the central axis A and extending in the circumferential direction dc. Among other things, the fixing member 72 is arranged outside the writing member 12 . The fixing member 72 is arranged between the writing member 12 and the barrel 20 in the radial direction. A gap is formed between the inner peripheral surface 73 of the fixing member 72 and the writing member 12 along the radial direction. This gap serves as a flow path for the air flowing out of the accommodation 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 . A rear end portion of the tubular member 27 protrudes rearward from the stepped portion 23 of the inner shaft 22, and the fixing member 72 is fixed to this rear end portion. The fixing member 72 is attached to the tubular member 27 by, for example, adhesion, press-fitting, or the like. As the material of the fixing member 72, for example, an elastic material such as rubber can be used.

The moving member 74 is a member arranged radially inside the tubular member 27 . The moving member 74 has an annular shape surrounding the central axis A and extending in the circumferential direction dc. In this embodiment, the moving member 74 is arranged between the first elastic 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 elastic force of the first elastic member 42 . As a result, when the writing member 12 moves forward when transitioning from the retracted state to the projected state, the moving member 74 receives the pressing force from the first receiving portion 14 and moves forward together with the writing member 12 . Further, when the writing member 12 moves backward when transitioning from the projected state to the retracted state, the moving member 74 receives the elastic force of 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 integrally with the writing member 12 when transitioning from the retracted state to the projected state and when transitioning from the projected state to the retracted state.

In the example shown in FIG. 2, the moving member 74 is in contact with the tubular member 27. As shown in FIG. In particular, the outer peripheral surface 75 of the moving member 74 located radially outward is in contact with the inner peripheral surface of the tubular member 27 . The outer peripheral surface 75 of the moving member 74 may be in contact with the cylindrical member 27 over the entire circumference in the circumferential direction dc, or may be partially provided with a gap, which will be described later, so that Only a part may contact the tubular member 27 . When the moving member 74 is in contact with the cylindrical member 27 , the moving member 74 moves while contacting the cylindrical member 27 when the moving member 74 moves back and forth. Thereby, a frictional force is generated between the moving member 74 and the tubular member 27 . As a result, the moving speed of the moving member 74 with respect to the tubular member 27 is reduced. As described above, in the projecting state, when the knock member 50 is pressed forward and then released, 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 with respect to the tubular member 27 is reduced, so that the writing member 12 slowly moves rearward after the user releases the pressing force of the knock member 50 . Therefore, the knock member 50 also slowly moves rearward. As a result, it is possible to give a feeling of high quality to the appearing/removing operation of the writing instrument 10 .

In the retracted state, the writing member 12 is urged forward through the rotating cam member 60 by the repulsive force of the second repulsive member 44 . Therefore, the first receiving portion 14 of the writing member 12 is in close contact with the moving member 74 in the retracted state. That is, the space between the moving member 74 and the first receiving portion 14 is sealed.

The elastic force of the first elastic member 42 is greater than the elastic force of the second elastic member 44 . When the moving member 74 is in contact with the cylindrical member 27, the elastic force of the first elastic member 42 is the frictional force generated between the moving member 74 and the cylindrical member 27 and the second elastic member. It is larger than the sum with the elastic force of 44. Thus, in the retracted state, the moving member 74 is positioned at the rearmost portion of the movable range in the axial direction da, and contacts the fixed member 72 from the front in the axial direction da. Among other things, the moving member 74 is in close contact with the fixed member 72 . That is, the space between the moving member 74 and the fixed member 72 is sealed. Therefore, the rear end of the housing space S is sealed by the sealing mechanism 70 .

In a conventional retractable writing instrument, a sealing member such as an O-ring is in close contact with a member such as a barrel in a radial direction, thereby sealing a space for accommodating the pen tip. In such a writing instrument, when the sealing member moves back and forth together with the writing member, the sealing member may slide against a member such as the barrel, and the sealing member may be worn or damaged. If a gap occurs between the barrel and the sealing member due to wear or breakage of the sealing member, it becomes impossible to maintain the housing space in an airtight state. This may cause the ink to dry out at the nib.

In contrast, in the present embodiment, the accommodation space S for the pen tip 13 is sealed by the fixing member 72 and the moving member 74 coming into contact with each other in the axial direction da. As a result, even if the moving member 74 is worn or damaged and a gap is generated between the cylindrical member 27 and the moving member 74, the fixed member 72 and the moving member 74 are in close contact with each other in the axial direction da. The airtightness of the space S can be maintained.

In addition, when the sealing member is in close contact with a member such as a barrel in the radial direction as in the prior art to seal the housing space of the nib, if the sealing member is smaller than a predetermined size, the sealing member However, a gap is generated between the housing and a member such as the shaft cylinder, and the housing space cannot be properly sealed. Further, if the sealing member is larger than the predetermined size, the frictional force generated between the sealing member and a member such as a barrel increases, preventing the writing member 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 parts.

In contrast, in the present embodiment, the moving 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 dimensional accuracy of the moving member 74 and the fixed member 72 is improved. The moving member 74 can be properly brought into close contact with the fixed member 72 even if the height is not high. As a result, it is possible to suppress an increase in the manufacturing cost of the component.

When the space between the writing member 12 and the cylindrical member 27 is completely sealed by the moving member 74, it is sealed by the lid portion 17 and the moving member 74 when the writing member 12 moves forward from the retracted state. As the volume of the closed space decreases, the pressure in this space increases. In this case, the increased pressure may generate a force pushing the writing member 12 back. As a result, the user may have to apply a large pressing force to the knock member 50 in order to shift the writing instrument 10 from the retracted state to the protruded state. Further, when the lid portion 17 is opened while the pressure in the space sealed by the lid portion 17 and the moving member 74 is increased, the pressure in the space is suddenly reduced at the moment the lid portion 17 is opened. This rapid decrease in pressure may cause ink to leak from the nib 13 . As will be described later, this increased pressure can also serve as an assist force for opening the lid portion 17 when the pen tip 13 pushes the lid portion 17 forward. Therefore, the 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 embodiments.

In this embodiment, the moving member 74 includes a channel 76 that allows air to flow along the axial direction da. As a result, when the writing member 12 moves forward from the retracted state, 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 are separated. are communicated via a channel 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. As a result, the user can press the knock member 50 forward without receiving the force of pushing back the writing member 12 due to the pressure in this space. Moreover, 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, so ink leakage from the nib 13 can be suppressed.

Hereinafter, examples of specific shapes of such flow channels 76 will be described with reference to FIGS. 5 to 11. FIG. 5 to 11 are transverse cross-sectional views corresponding to line AA in FIG. 5 to 11, the inner peripheral surface 73 of the fixing member 72 when viewed along the axial direction da is indicated by broken lines. 5 to 11, illustration of the writing member 12 is omitted.

The flow path 76 may include a notch portion 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 a cutout portion 77 formed in a circular outer peripheral surface 75. As shown in FIG. In particular, in the illustrated example, the moving member 74 has a plurality of notches 77 arranged in the circumferential direction dc. In the present embodiment, the cutout portion 77 extends parallel to the axial direction da, but the invention is not limited to this, and the cutout portion 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 the extension of the outer peripheral surface 75 . In the example shown in FIG. 7, the notch 77 has an arcuate shape that protrudes radially inward. In the example shown in FIG. 8, the cutout portion 77 has a shape obtained by combining two circular arcs that protrude outward in the radial direction. 5, the moving member 74 has four notches 77, and in the example shown in FIG. 6, the moving member 74 has six notches 77, In the example shown in FIG. 7, the moving member 74 has eight notches 77, and in the example shown in FIG. 8, the moving member 74 has twelve notches 77. , the number of notches 77 is arbitrary and not limited to these.

Channel 76 may include a through hole 78 that extends through moving member 74 . In the example shown in FIGS. 9 and 10, the moving member 74 has a through hole 78 extending along the axial direction da. In particular, in the illustrated example, the moving member 74 has a plurality of through holes 78 arranged in the circumferential direction dc. Although the through hole 78 extends in parallel with the axial direction da in the present embodiment, the through hole 78 may extend in a direction inclined with respect to the axial direction da. In the example shown in FIG. 9, the through hole 78 has a circular shape when viewed from the axial direction da. In the example shown in FIG. 10, the through hole 78 has an oval shape extending along the circumferential direction dc. 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 3 through holes 78. , the number of through-holes 78 is arbitrary and not limited to these. Note that the flow path 76 may include both the notch 77 and the through hole 78 .

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

In the examples shown in FIGS. 5 to 11, the entire flow path 76 is located radially outside the inner peripheral surface of the fixing member 72 when viewed in the axial direction da. That is, when viewed from the axial direction da, the entire flow path 76 and the fixing member 72 overlap. In this case, when the moving member 74 is brought into close contact with the fixed member 72 in the axial direction da, the fixed member 72 completely closes the flow path 76 . As a result, the rear end of the accommodation space S is properly sealed in the retracted state.

Next, operations of the retractable mechanism 40 and the sealing mechanism 70 will be described with reference to FIGS. 1 to 4. FIG.

When the user presses the knock member 50 forward in the retracted state (FIGS. 1 and 2), the writing member 12 moves forward via the rotating cam member 60. As shown in FIG. At this time, the moving member 74 also moves forward integrally with the writing member 12 . When the moving member 74 is separated 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 separated from the passage 76 and the inner peripheral surface 73 of the fixing member 72 and the writing member. 12 through a gap formed between them. When the writing member 12 moves further forward, the pen tip 13 pushes the lid portion 17 forward against the repulsive force of the resilient member 18, thereby opening the lid portion 17.例文帳に追加At this time, since the space between the lid portion 17 and the moving member 74 and the space behind the moving member 74 communicate with each other, the user pushes back the writing member 12 by the pressure in this space. The knock member 50 can be pushed forward without receiving force. Moreover, 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, so ink leakage from the nib 13 can be suppressed. Further, 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. As a result, the writing instrument 10 transitions from the retracted state to the projected state.

Further, when the user presses the knock member 50 forward in the projecting state (FIGS. 3 and 4), the writing member 12 moves forward by a minute distance. When the forward pressure of the knock member 50 is released, the writing member 12 moves rearward due to the repulsive force of the first repulsive member 42, and the pen tip 13 retracts from the front end opening 20a. Further, when the writing member 12 moves rearward, the pen point 13 is accommodated in the accommodation space S, and the elastic force of the elastic member 18 causes the lid portion 17 to close the front end of the front sealing member 29 . Further, when the writing member 12 moves rearward, the moving member 74 comes into close contact with the fixed member 72 in the axial direction da. At this time, the entire passage 76 is blocked by the fixing member 72, and the accommodation space S is hermetically sealed. By sealing the accommodation space S, drying of the ink at the nib 13 is suppressed in the immersed state.

If the moving member 74 does not have the flow path 76, the volume of the space sealed by the lid portion 17 and the moving member 74 decreases when the writing member 12 moves forward from the retracted state. The pressure in this space increases accordingly. In this case, due to the increased pressure, the lid portion 17 receives a force acting in the opening direction of the lid portion 17 . Therefore, this increased pressure serves as an assist force for opening the lid portion 17 when the pen tip 13 pushes the lid portion 17 forward. Therefore, a form in which the moving member 74 does not have the flow path 76 is also one of the preferred embodiments.

The writing instrument 10 of the present embodiment includes a barrel 20 having a front end opening 20a, a writing member 12 having a pen tip 13, a retraction mechanism 40 for retracting the pen tip 13 from the front end opening 20a, and retraction of the pen tip 13. a sealing mechanism 70 that seals the housing space S of the pen tip 13 in the state, the sealing mechanism 70 includes a fixed member 72 fixed to the barrel 20 and a moving member that can move back and forth integrally with the writing member 12. The housing space S is hermetically sealed by the fixing member 72 and the moving member 74 coming into contact with each other in the axial direction da.

According to the writing instrument 10 as described above, the housing space S for the pen tip 13 is sealed by the contact between the fixed member 72 and the moving member 74 in the axial direction da. As a result, even if the moving member 74 is worn or damaged and a gap is generated between the cylindrical member 27 and the moving member 74, the fixed member 72 and the moving member 74 are in close contact with each other in the axial direction da. The airtightness of the space S can be maintained. Therefore, in the immersed state, the sealed state of the housing space S can be sufficiently ensured.

The writing instrument 10 of this embodiment has an elastic member 42 that biases the moving member 74 rearward.

According to such a writing instrument 10, since the moving member 74 is pressed against the fixed member 72 along the axial direction da by the elastic force of the elastic member 42, the dimensional accuracy of the moving member 74 and the fixed member 72 is not high. However, the moving member 74 can be properly brought into close contact with the fixed member 72 . As a result, it is possible to suppress an increase in the manufacturing cost of the component.

In the writing instrument 10 of this embodiment, the resilient member 42 urges the writing member 12 rearward via the moving member 74 .

According to the writing instrument 10 as described above, the resilient member 42 exhibits both the function of urging the moving member 74 rearward and the function of urging the writing member 12 rearward. In other words, one elastic member 42 can urge the moving member 74 rearward and the writing member 12 rearward. Therefore, an increase in the number of parts can be suppressed.

The writing instrument 10 of this embodiment has a tubular member 27 that surrounds at least a portion of the accommodation space S, and the moving member 74 is in contact with the tubular member 27 .

According to such a writing instrument 10 , a frictional force is generated between the moving member 74 and the cylindrical member 27 . As a result, the moving speed of the moving member 74 with respect to the cylindrical member 27 is reduced. As a result, the knock member 50 slowly moves rearward together with the writing member 12 when transitioning from the protruded state to the retracted state. As a result, it is possible to give a feeling of high quality to the appearing/removing operation of the writing instrument 10 .

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

In the writing instrument 10 of this embodiment, the channel 76 includes a notch 77 formed on the outer peripheral surface of the moving member 74 .

In the writing instrument 10 of this embodiment, the channel 76 includes a through-hole 78 passing through the moving member 74 .

According to such a writing instrument 10, when the writing member 12 moves forward from the retracted state, if the moving member 74 separates from the fixed member 72, the space between the lid portion 17 and the moving member 74 and the moving member 74 move. The space behind is communicated with through a 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. As a result, the user can press the knock member 50 forward without receiving the force of pushing back the writing member 12 due to the pressure in this space. Moreover, 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, so ink leakage from the nib 13 can be suppressed.

In the writing instrument 10 of this embodiment, the entire flow path 76 and the fixing member 72 overlap when viewed from the axial direction da.

According to the writing instrument 10 as described above, when the moving member 74 is in close contact with the fixing member 72 in the axial direction da, the fixing member 72 blocks the flow path 76 as a whole. As a result, the rear end of the accommodation space S is properly sealed in the retracted state.

10 Writing instrument 12 Writing member 13 Pen tip 14 First receiving portion 15 Protruding portion 17 Lid portion 18 Resilient member 20 Axle tube 20a Front end opening portion 21 Front shaft 22 Inner shaft 22a Large diameter portion 22b Small diameter portion 23 Stepped portion 24 Groove portion 25 Outside Shaft 26 First connecting member 27 Cylindrical member 28 Second receiving portion 29 Front sealing member 30 Tip member 31 Rear shaft 32 Inner shaft 35 Outer shaft 36 Second connecting member 38 Crown 40 Retraction mechanism 42 First elastic member source)
44 Second elastic member 50 Knock member 52 Operation portion 54 Expanded diameter portion 56 Hole portion 58 Inward protrusion 60 Rotating cam member 62 Rear protrusion 64 Engaging portion 70 Sealing mechanism 72 Fixed member 73 Inner peripheral surface 74 Moving member 75 Outer peripheral surface 76 Flow path 77 Notch 78 Through hole da Axial direction dc Circumferential direction A Central axis S Accommodating space

Claims (8)

A barrel having a front end opening, a writing member having a pen tip, a retracting mechanism for retracting the pen tip from the front opening, and a sealing mechanism for sealing the pen tip storage space when the pen tip is retracted. and a writing instrument comprising
The sealing mechanism is
a fixing member fixed to the barrel;
a moving member that can move back and forth integrally with the writing member,
A writing instrument, wherein the housing space is hermetically sealed by axial contact between the fixed member and the movable member. 2. The writing instrument according to claim 1, comprising an elastic member that biases said moving member backward. 3. The writing instrument according to claim 2, wherein said elastic member urges said writing member rearward via said moving member. Having a tubular member surrounding at least part of the accommodation space,
The writing instrument according to any one of claims 1 to 3, wherein the moving member is in contact with the cylindrical member. The writing instrument according to any one of claims 1 to 4, wherein the moving member includes a channel that allows air to flow along the axial direction. 6. The writing instrument according to claim 5, wherein the flow path includes a notch formed on the outer peripheral surface of the moving member. 7. The writing instrument according to claim 5, wherein said flow path includes a through hole passing through said moving member. The writing instrument according to any one of claims 5 to 7, wherein the entire flow path and the fixing member overlap when viewed from the axial direction.

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