Writing implement

Abstract

A writing instrument (10) includes a barrel (20) having an opening (22a); a writing member having a pen tip (13); an advancing and retracting mechanism (40) that advances and retracts the pen tip (13) from the opening (22a); and a sealing mechanism (70) that seals a housing space (S) of the pen tip (13) in a retracted state of the pen tip (13), the sealing mechanism (70) having a lid member (71) that rotates around a rotational axis (79) to close and open the opening (22a) and a guide portion (80) that guides the lid member (71), the lid member (71) having a closing portion (72) having a closing surface (73) that closes the opening (22a) and a first side surface (74), and a leg portion (76) that supports the closing portion (72), the guide portion (80) having a first guide surface (82) that faces the first side surface (74) when the lid member (71) closes the opening (22a), and does not face the first side surface (74) when the lid member (71) opens the opening (22a).

Description

TECHNICAL FIELD

[0001] The present invention relates to a writing instrument.BACKGROUND ART

[0002] Conventionally, there is known a writing instrument including a barrel, a writing member having a pen tip portion, and an advancing and retracting mechanism that advances and retracts the pen tip portion from the barrel. In addition, as such a writing instrument, there is also known a writing instrument including a sealing mechanism that seals a housing space of a pen tip to prevent ink from drying at the pen tip in a retracted state of the pen tip.

[0003] JP 2007-112032 A discloses a writing instrument including a barrel, a writing body housed inside the barrel, a lid disposed in front of the barrel, and a spring that biases the lid in a closing direction. The lid and the spring are rotatably attached to the barrel by an axial rod serving as a rotational axis. In this writing instrument, when the writing body moves forward, the lid is pressed against a distal end of the writing body to open. In addition, when the writing body moves rearward in this state, the writing body is housed inside the barrel, and the lid is closed by a spring force of the spring to close the barrel. Thus, it is possible to prevent the ink from drying in the writing body while the writing body is housed in the barrel.

[0004] In such a writing instrument, at the time of assembly of the sealing mechanism, it is necessary to insert the axial rod into the lid and the barrel in a state in which the lid is fixed to the barrel. At this time, if a position of the lid relative to the barrel is shifted, it is sometimes difficult to appropriately insert the axial rod. Under such circumstances, it is required to make the assembly of the sealing mechanism easy in the writing instrument including the sealing mechanism.SUMMARY OF THE INVENTION

[0005] The present invention has been made in view of such a point, and an object thereof is to provide a writing instrument including a sealing mechanism that can be easily assembled.

[0006] A writing instrument according to the present invention is [1] a writing instrument including: a barrel having an opening; a writing member having a pen tip; an advancing and retracting mechanism that advances and retracts the pen tip from the opening; and a sealing mechanism that seals a housing space of the pen tip in a retracted state of the pen tip, wherein the sealing mechanism has a lid member that rotates around a rotational axis to close and open the opening, and a guide portion that guides the lid member, the lid member has a closing portion having a closing surface that closes the opening and a first side surface, and a leg portion that supports the closing portion, and the guide portion has a first guide surface that faces the first side surface when the lid member closes the opening, and does not face the first side surface when the lid member opens the opening.

[0007] A writing instrument according to the present invention is the writing instrument according to [1], wherein the first side surface is a surface facing a side of the rotational axis, and the first guide surface is a surface facing a side of the opening.

[0008] A writing instrument according to the present invention is the writing instrument according to [1] or [2], wherein the lid member has two of the leg portions, the first side surface is located between the two leg portions, and the guide portion is located in a space between the two leg portions when the lid member closes the opening.

[0009] A writing instrument according to the present invention is the writing instrument according to [1] or [2], wherein the sealing mechanism has two of the guide portions, and the leg portion is located in a space between the two guide portions when the lid member closes the opening.

[0010] A writing instrument according to the present invention is: the writing instrument according to any one of [1] to [4], wherein the guide portion has a second guide surface that guides the leg portion.

[0011] A writing instrument according to the present invention is the writing instrument according to any one of [1] to [5], wherein the closing surface comes into contact with a contact surface surrounding the opening when the lid member closes the opening, and the rotational axis is located opposite to the housing space with respect to an extended plane of the contact surface.

[0012] According to the present invention, it is possible to provide the writing instrument including the sealing mechanism that can be easily assembled.BRIEF DESCRIPTION OF DRAWINGS

[0013] [Fig. 1] Fig. 1 is a view for describing an embodiment of the present invention, and is a longitudinal sectional view illustrating an example of a writing instrument in a retracted state. [Fig. 2] Fig. 2 is a longitudinal sectional view illustrating the writing instrument of Fig. 1 in a protruding state. [Fig. 3] Fig. 3 is a perspective view illustrating a sealing mechanism of the writing instrument. [Fig. 4] Fig. 4 is a perspective view illustrating a guide portion of the sealing mechanism. [Fig. 5] Fig. 5 is a view illustrating a lid member and the guide portion in a retracted state. [Fig. 6] Fig. 6 is a sectional view taken along line VI-VI in Fig. 5. [Fig. 7] Fig. 7 is a view for describing an example of an assembly process of the sealing mechanism. [Fig. 8] Fig. 8 is a view for describing an example of the assembly process of the sealing mechanism. [Fig. 9] Fig. 9 is a perspective view illustrating the lid member and the guide portion in Fig. 8. [Fig. 10] Fig. 10 is a view for describing an example of the assembly process of the sealing mechanism. [Fig. 11] Fig. 11 is a view for describing an example of the assembly process of the sealing mechanism. [Fig. 12] Fig. 12 is a view illustrating the lid member and the guide portion in the middle of opening and closing. [Fig. 13] Fig. 13 is a view illustrating a modification of the sealing mechanism, and is a perspective view illustrating a lid member of the sealing mechanism and a guide portion. [Fig. 14] Fig. 14 is a perspective view illustrating the guide portion in Fig. 13. [Fig. 15] Fig. 15 is a view illustrating the lid member and the guide portion in a retracted state. [Fig. 16] Fig. 16 is a sectional view taken along line XVI-XVI in Fig. 15. BEST MODE FOR CARRYING OUT THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that, in the drawings attached to the present specification, scales, vertical and horizontal dimensional ratios, and the like are appropriately changed and exaggerated from the actual ones for convenience of illustration and ease of understanding.

[0015] In addition, terms such as "parallel", "orthogonal", "same", and the like, values of length and angle, and the like, which specify shapes and geometric conditions and degrees thereof, used in the present specification are interpreted including a range in which similar functions can be expected without being bound by a strict meaning.

[0016] In the present specification, a direction in which a central axis A of a writing instrument 10 extends (a longitudinal direction) is defined as an axial direction da, a direction orthogonal to the axial direction da is defined as a radial direction, and a direction along a circumference around the central axis A is defined as a circumferential direction. Along the axial direction da, a pen tip side is defined as front or forward, and a side opposite to the pen tip is defined as rear or rearward. In addition, along the radial direction, a side approaching the central axis A is defined as an inside or inward, and a side away from the central axis A is defined as an outside or outward.

[0017] Fig. 1 is a view for describing the embodiment of the present invention, and is a longitudinal sectional view illustrating an example of the writing instrument 10 in a retracted state, and Fig. 2 is a longitudinal sectional view illustrating the writing instrument 10 in a protruding state.

[0018] The writing instrument 10 of the present embodiment includes a writing member 12, a barrel 20, an advancing and retracting mechanism 40, and a sealing mechanism 70. The writing instrument 10 extends along the central axis A. The writing member 12 is a member that forms a handwriting on a writing surface such as a paper surface. The writing member 12 is housed in the barrel 20. Examples of the writing member 12 include members used for a ballpoint pen, a fountain pen, and a marker. In the present embodiment, an example in which the writing instrument 10 is a fountain pen will be described. The writing member 12 of the present embodiment includes a pen tip 13 provided at a front end portion, a storage tube 15 storing ink, a first receiving portion 17, and a protrusion 19. The storage tube 15 may be, for example, a cartridge type or a converter. The first receiving portion 17 is a surface facing forward in a step portion formed on an outer surface of the writing member 12, and receives a spring force of a first resilient member 42 described later. The protrusion 19 protrudes radially outward from the main body of the writing member 12.

[0019] The advancing and retracting mechanism 40 is a mechanism for alternately switching the writing instrument 10 between a protruding state in which the pen tip 13 protrudes from a front end opening 20a of the barrel 20 and a retracted state in which the pen tip 13 is retracted from the front end opening 20a.

[0020] The barrel 20 includes a front barrel 21, a distal end member 30 disposed in front of the front barrel 21, and a rear barrel 31 disposed at the rear of the front barrel 21. A central axis of the barrel 20 coincides with the central axis A of the writing instrument 10. The front end opening 20a through which the pen tip 13 can pass is provided at a front end of the barrel 20. In the present embodiment, the front end opening 20a is formed at a front end of the distal end member 30.

[0021] The front barrel 21 is a member having a substantially tubular shape, and is intended to be gripped by fingers when a user performs writing with the writing instrument 10. The front barrel 21 of the present embodiment includes an inner barrel 22, an outer barrel 25 disposed radially outward of the inner barrel 22, and a first connecting member 26.

[0022] The inner barrel 22 is a member that houses the front part of the writing member 12 and defines a housing space S of the pen tip 13. The inner barrel 22 is a member having a substantially tubular shape having a central axis coinciding with the central axis A. In the present embodiment, the inner barrel 22 houses the entire pen tip 13 in the retracted state. A groove 24 to be engaged with the protrusion 19 of the writing member 12 is formed on an inner surface of the inner barrel 22. The groove 24 is a groove extending in the axial direction da, and the writing member 12 is supported so as to be movable in the axial direction da and non-rotatable in the circumferential direction with respect to the barrel 20 when the protrusion 19 of the writing member 12 is located in the groove 24. The inner barrel 22 is made of, for example, a resin material such as acrylonitrile-styrene (AS) copolymer resin, acrylonitrile-butadiene-styrene (ABS) copolymer resin, polycarbonate (PC), polypropylene (PP), polyethylene (PE), or elastomer, a rubber material such as nitrile butadiene rubber (NBR), or the like. Note that the inner barrel 22 may be configured using a single member or a plurality of members.

[0023] An opening 22a through which the pen tip 13 can pass is formed at a distal end portion of the inner barrel 22. A contact surface 22b is formed around the opening 22a. The contact surface 22b is a surface with which a lid member 71 described later comes into contact in the retracted state.

[0024] The outer barrel 25 is a member that is visually recognized by the user, the member being grasped by the fingers when the user performs writing with the writing instrument 10. Therefore, the outer barrel 25 is made of an appropriate material in consideration of designability and ease of holding for the user. For example, the outer barrel 25 may be made of resin, elastomer, metal, wood, or the like. The first connecting member 26 is a member constituting a connecting portion with the rear barrel 31. The first connecting member 26 is fixed to a rear end portion of at least one of the inner barrel 22 and the outer barrel 25. For example, the first connecting member 26 may be fixed to the rear end portion of at least one of the inner barrel 22 and the outer barrel 25 by adhesion or insert molding. The first connecting member 26 is made of, for example, resin, metal, or the like. Note that the present invention is not limited to the illustrated example, and the outer barrel 25 and the first connecting member 26 may be omitted. For example, the entire front barrel 21 may be integrally formed.

[0025] The distal end member 30 is a member that forms a distal end part of the barrel 20. The distal end member 30 has a function of protecting a front end portion of the front barrel 21, the lid member 71, and a resilient member 90. The distal end member 30 has a substantially truncated cone shape, and an outer diameter thereof decreases toward the front. The front end opening 20a through which the pen tip 13 protrudes and is retracted is formed at a front end of the distal end member 30. When a rear end portion of the distal end member 30 is attached to the front end portion of the front barrel 21, the distal end member 30 is connected to the front barrel 21. The distal end member 30 is connected to the front barrel 21 by, for example, press-fitting, adhesion, or screwing of a screw portion.

[0026] The rear barrel 31 is a member having a substantially tubular shape and disposed at the rear of the front barrel 21. The rear barrel 31 includes an inner barrel 32, an outer barrel 35 disposed radially outward of the inner barrel 32, a second connecting member 36, and a head cap 38.

[0027] The inner barrel 32 is a member that houses a rear part of the writing member 12. The inner barrel 32 is a member having a substantially tubular shape. The inner barrel 32 is made of, for example, resin, metal, wood, or the like. A plurality of serrated cam teeth protruding forward and a groove formed between the cam teeth and extending in the axial direction da are formed on an inner peripheral surface of the inner barrel 32.

[0028] The outer barrel 35 is a member visually recognized by the user. Therefore, the outer barrel 35 is made of an appropriate material in consideration of designability and the like. For example, the outer barrel 35 may be made of resin, elastomer, metal, wood, or the like. The second connecting member 36 is a member constituting the connecting portion with the front barrel 21. The second connecting member 36 is fixed to a front end portion of at least one of the inner barrel 32 and the outer barrel 35. For example, the second connecting member 36 may be fixed to the front end portion of at least one of the inner barrel 32 and the outer barrel 35 by adhesion or insert molding. The second connecting member 36 is made of, for example, resin, metal, or the like. Note that the present invention is not limited to the illustrated example, and the inner barrel 32 and the outer barrel 35 may be configured using a single member. The inner barrel 32, the outer barrel 35, and the second connecting member 36 may be configured using a single member. That is, the entire rear barrel 31 may be integrally formed.

[0029] The advancing and retracting mechanism 40 is a mechanism for alternately switching the writing instrument 10 between the protruding state and the retracted state. The advancing and retracting mechanism 40 of the present embodiment includes a push member 50, a rotary cam member 60, the first resilient member 42, and a second resilient member 44.

[0030] The first 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 17 of the writing member 12 and a second receiving portion 28 of the barrel 20 (the front barrel 21). The second receiving portion 28 is a stepped portion provided on an inner peripheral surface of the barrel 20 (the front barrel 21) and includes a surface facing rearward. In the present embodiment, the first receiving portion 17 receives a spring force from the first resilient member 42. Thus, the first resilient member 42 constantly biases the writing member 12 rearward of the barrel 20. Note that the first resilient member 42 constitutes a part of the advancing and retracting mechanism 40 and constitutes a part of the sealing mechanism 70 as described later.

[0031] The push member 50 is intended to be operated by the user. The push member 50 includes an operation portion 52 and a large-diameter portion 54 located in front of the operation portion 52. The operation portion 52 is a part pressed by the user's finger or the like. The operation portion 52 protrudes rearward from a rear end of the barrel 20 (the rear barrel 31). In the retracted state and the protruding state, a rear end of the operation portion 52 protrudes rearward from the rear end of the barrel 20. The large-diameter portion 54 has a radial dimension larger than a radial dimension of the operation portion 52. An inner diameter of a rear end portion of the barrel 20 has a size that allows passage of the operation portion 52 but does not allow passage of the large-diameter portion 54. Therefore, the push member 50 does not come out rearward from the rear end portion of the barrel 20.

[0032] A cam tooth protruding forward are formed at a front end of the large-diameter portion 54. In addition, on an outer peripheral surface of the large-diameter portion 54, a protrusion which engages with the groove formed on the inner peripheral surface of the barrel 20 (the rear barrel 31) is formed. The push member 50 is disposed to be movable in the axial direction da and not to be rotatable in the circumferential direction in a state in which the protrusion engages with the groove of the barrel 20.

[0033] A hole 56 extending in the axial direction da is formed inside the push member 50. In the present embodiment, the hole 56 is open at a front end of the push member 50 and closed at a rear end of the push member 50. An inward protrusion 58 protruding radially inward is formed on an inner surface of the hole 56.

[0034] An O-ring 59 is disposed on an outer peripheral surface of the push member 50. The O-ring 59 is disposed in a groove formed to annularly extend in the circumferential direction on the outer peripheral surface of the push member 50. In the example illustrated in Fig. 1, the O-ring 59 is disposed between the operation portion 52 and the large-diameter portion 54 of the push member 50. The O-ring 59 has a function of sealing between the inner peripheral surface of the barrel 20 (the rear barrel 31) and the outer peripheral surface of the push member 50 in the retracted state illustrated in Fig. 1. The O-ring 59 is made of, for example, an elastic material such as rubber.

[0035] 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 groove of barrel 20. A cam surface inclined with respect to the axial direction da and the circumferential direction is formed at rear ends of the ridges. The cam surface engages with the cam tooth of the push member 50. The rotary cam member 60 has a rear protrusion 62 that protrudes rearward along the axial direction da. An engaging portion 64 is provided at a rear end of the rear protrusion 62. The engaging portion 64 is a protrusion protruding radially outward from the rear protrusion 62. The engaging portion 64 engages with the inward protrusion 58 of the push member 50 to restrict the movement of the push member 50 and the rotary cam member 60 in the axial direction da.

[0036] The second resilient member 44 is disposed between the push member 50 and the rotary cam member 60. The second resilient member 44 is, for example, a coil spring. The second resilient member 44 is disposed in the barrel 20 at the rear of the writing member 12. Specifically, the second resilient member 44 is disposed in a compressed state between the push member 50 and the rotary cam member 60. Therefore, the second resilient member 44 constantly biases the push member 50 rearward of the rotary cam member 60. Thus, although the push member 50 moves rearward of the rotary cam member 60, the engaging portion 64 of the rotary cam member 60 engages with the inward protrusion 58 of the push member 50, so that the push member 50 is prevented from further moving rearward of the rotary cam member 60. The push member 50 is biased rearward by the second resilient member 44 in a state in which the engaging portion 64 of the rotary cam member 60 engages with the inward protrusion 58 of the push member 50, so that rattling of the push member 50 is suppressed.

[0037] Since specific structures and operations of the groove of the barrel 20, the cam tooth and the protrusion of the push member 50, and the ridges and the cam surface of the rotary cam member 60 are known, detailed description thereof will be omitted. As an example, a structure of a mechanism disclosed in JP 2013-006281 A can be used as these specific structures.

[0038] The writing instrument 10 of the present embodiment includes the sealing mechanism 70 that seals the housing space S of the pen tip 13. Hereinafter, the sealing mechanism 70 will be described with reference to Figs. 1 to 6. Fig. 3 is a perspective view illustrating the sealing mechanism 70. Fig. 4 is a perspective view illustrating a guide portion 80 of sealing mechanism 70. Fig. 5 is a view illustrating the lid member 71 and the guide portion 80 in the retracted state when viewed from a direction perpendicular to the contact surface 22b and a closing surface 73 described later. Fig. 6 is a sectional view taken along line VI-VI in Fig. 5. The sealing mechanism 70 of the present embodiment is a mechanism that seals a front end of the housing space S. The sealing mechanism 70 includes the contact surface 22b of the barrel 20 (the inner barrel 22), the lid member 71, a pin 79, the guide portion 80, and the resilient member 90.

[0039] The inner barrel 22 has the opening 22a through which the pen tip 13 can pass and the contact surface 22b surrounding the opening 22a. In the example illustrated in Figs. 1 and 3, the lid member 71 and the resilient member 90 are attached to the inner barrel 22 via the pin 79.

[0040] The lid member 71 closes a front end of the inner barrel 22 in the retracted state to seal the housing space S, and allows the pen tip 13 to protrude in the protruding state. The lid member 71 is configured to be rotatable around the pin 79 serving as a rotational axis. The lid member 71 includes a closing portion 72 that closes the opening 22a, a leg portion 76 that supports the closing portion 72, and a locking portion 78 that locks a first end portion 95, which will be described later, of the resilient member 90. The closing portion 72 has the closing surface 73 which faces the contact surface 22b and comes into contact with the contact surface 22b in a state in which the lid member 71 closes the opening 22a, and a first side surface 74. In the present embodiment, the closing surface 73 is a plane extending in parallel to the contact surface 22b in the state in which the lid member 71 closes the opening 22a. The first side surface 74 is a side surface extending in a direction intersecting the closing surface 73. In the present embodiment, the first side surface 74 is a plane extending orthogonal to the closing surface 73.

[0041] The leg portion 76 is a member that supports the closing portion 72. The lid member 71 has two leg portions 76. One end of the leg portion 76 is fixed to the closing portion 72. In the example illustrated in Fig. 3, the leg portion 76 is integrally formed with the closing portion 72. The other end of the leg portion 76 is bent along at least a part of the periphery of the pin 79, and serves as an attachment portion 77 for attaching the lid member 71 to the pin 79. As illustrated in Fig. 8, the attachment portion 77 is formed by bending the other end of the leg portion 76 in a loop shape. The lid member 71 is attached to the pin 79 by inserting the pin 79 into the loop of the attachment portion 77.

[0042] In the present embodiment, the first side surface 74 is a surface facing the attachment portion 77 side. The pin 79 serving as the rotational axis is attached to the attachment portion 77. Therefore, the first side surface 74 is a surface facing the rotational axis (the pin 79) side. In addition, in the example illustrated in Fig. 5, the first side surface 74 is located between the two leg portions 76.

[0043] The resilient member 90 is a member that biases the lid member 71 toward the contact surface 22b by the spring force. The resilient member 90 is, for example, a torsion spring. The resilient member 90 includes a coil portion 91, a first arm 93, and a second arm 97. The coil portion 91 is a main body part of the torsion spring, and is a part that generates the spring force in the resilient member 90. The first arm 93 extends from the coil portion 91 and has the first end portion 95 on a side opposite to the coil portion 91. The lid member 71 has the locking portion 78 on the closing portion 72 on a side opposite to the closing surface 73, and the resilient member 90 is attached to the lid member 71 by locking the first end portion 95 to the locking portion 78. In the example illustrated in Fig. 3, the locking portion 78 is formed by folding back a tongue piece, which extends from a side surface of the closing portion 72 on a side opposite to the leg portion 76 (opposite to the first side surface 74), to the side opposite to the closing surface 73. The second arm 97 extends from the coil portion 91 and has a second end portion 99 on a side opposite to the coil portion 91. In the example illustrated in Fig. 3, the second arm 97 extends from the coil portion 91 to the side opposite to the first arm 93. The second end portion 99 is disposed in a recess 29 provided at a front end part of the inner barrel 22.

[0044] The pin 79 is a rod-shaped member extending in a direction orthogonal to the axial direction da. The pin 79 may be a solid columnar member or a hollow cylindrical member. In the example illustrated in Fig. 3, the pin 79 is inserted into a through hole 27 provided at the front end part of the inner barrel 22, the attachment portion 77 of the lid member 71, and the coil portion 91 of the resilient member 90. Thus, the lid member 71 and the resilient member 90 are attached to the barrel 20 (the inner barrel 22) via the pin 79. The lid member 71 can rotate around the pin 79 to one side and the other side to come into contact with the contact surface 22b or to be separated from the contact surface 22b. That is, the pin 79 also serves as the rotational axis of the lid member 71. Note that a gap serving as a clearance may be formed between an annular portion provided at a proximal end portion of the lid member 71 and an outer peripheral surface of the pin 79. Even in this case, the pin 79 is substantially the rotational axis of the lid member 71.

[0045] The lid member 71 is biased by the resilient member 90 in a direction of sealing the housing space S of the pen tip 13. In the present embodiment, in the retracted state, the closing surface 73 of the lid member 71 comes into contact with the contact surface 22b of the inner barrel 22 by the spring force of the resilient member 90 to close the opening 22a. Thus, the housing space S of the pen tip 13 is sealed (see Figs. 1 and 3). In this case, drying of the ink at the pen tip 13 is suppressed. At the time of transition from the retracted state to the protruding state, when the pen tip 13 moving forward pushes the lid member 71 forward so that the lid member 71 is opened, and the pen tip 13 protrudes forward through the opening 22a and the front end opening 20a (see Fig. 2). In this protruding state, writing by the writing instrument 10 becomes possible.

[0046] The guide portion 80 will be described mainly with reference to Figs. 4 to 6. The guide portion 80 is a member for guiding the lid member 71. In particular, the guide portion 80 has a function of guiding the lid member 71 such that the lid member 71 is disposed at a predetermined position at the time of assembly of the sealing mechanism 70. The guide portion 80 has a first guide surface 82 and a second guide surface 84. The first guide surface 82 is a surface with which the first side surface 74 of the lid member 71 is intended to come into contact at the time of assembly of the sealing mechanism 70. In the present embodiment, the first guide surface 82 is a plane extending perpendicularly to the contact surface 22b. In particular, the first guide surface 82 is a surface facing the opening 22a side along a direction parallel to the contact surface 22b. The first guide surface 82 is located so as to face the first side surface 74 when the lid member 71 closes the opening 22a. Note that the first guide surface 82 does not face the first side surface 74 when the lid member 71 opens the opening 22a. Here, a state in which the first side surface 74 and the first guide surface 82 face each other refers to a state in which the first side surface 74 and the first guide surface 82 oppose each other at an angle of 10 degrees or less. For example, the state in which the first side surface 74 and the first guide surface 82 face each other includes a case where the first side surface 74 and the first guide surface 82 are disposed in parallel. A state in which the first side surface 74 and the first guide surface 82 do not face each other refers to a state in which the first side surface 74 and the first guide surface 82 do not oppose each other and a state in which the first side surface 74 and the first guide surface 82 oppose each other at an angle exceeding 10 degrees. As illustrated in Figs. 5 and 6, the guide portion 80 is located in a space between the two leg portion 76 of the lid member 71 when the lid member 71 closes the opening 22a.

[0047] The second guide surface 84 is a surface that guides the leg portions 76. The second guide surface 84 has a function of guiding the leg portions 76 such that the lid member 71 is disposed at a predetermined position at the time of assembly of the sealing mechanism 70. In addition, the second guide surface 84 has a function of guiding the leg portions 76 and stably closing and opening the opening 22a by the lid member 71 when the lid member 71 rotates around the rotational axis (the pin) 79 to one side and the other side. In the example illustrated in Fig. 5, the second guide surface 84 is a surface extending perpendicularly to the contact surface 22b and also extending perpendicularly to the first guide surface 82. In the illustrated example, the guide portion 80 has two second guide surfaces 84 facing each other. One second guide surface 84 faces one leg portion 76 of the lid member 71, and the other second guide surface 84 faces the other leg portion 76 of the lid member 71. In particular, one second guide surface 84 extends parallel to one leg portion 76 of the lid member 71, and the other second guide surface 84 extends parallel to the other leg portion 76 of the lid member 71.

[0048] A height H of the guide portion 80 from the contact surface 22b is larger than a thickness T of the closing portion 72 of the lid member 71. In this case, the entire first side surface 74 can come into contact with the first guide surface 82 along the thickness direction of the closing portion 72 at the time of assembly of the sealing mechanism 70. Therefore, the guide portion 80 can stably guide the lid member 71 at the time of assembly of the sealing mechanism 70.

[0049] The rotational axis (the pin 79) of the lid member 71 is located opposite to the housing space S with respect to an extended plane 22c of the contact surface 22b (see Fig. 11). In particular, the entire rotational axis 79 of the lid member 71 is located opposite to the housing space S with respect to the extended plane 22c of the contact surface 22b. In other words, the rotational axis of the lid member 71 is located in front of the extended plane 22c of the contact surface 22b. This suppresses the first side surface 74 and the guide portion 80 from coming into contact with each other during opening and closing of the lid member 71 (see Fig. 12). The height H of the guide portion 80 from the contact surface 22b can be increased.

[0050] In a state in which the lid member 71 closes the opening 22a and the pin 79 is inserted into the attachment portion 77 of the lid member 71 and the through hole 27 of the inner barrel 22, a width W1 of a gap formed between the first side surface 74 and the first guide surface 82 in the direction parallel to the contact surface 22b may be, for example, 0 mm or more and 1.0 mm or less. When the width W1 is 0 mm or more, it is possible to suppress the first side surface 74 and the guide portion 80 from coming into contact with each other and hindering the smooth movement of the lid member 71 when the lid member 71 rotates around the rotational axis (the pin) 79 to one side and the other side. Since the width W1 is 1.0 mm or less, it is possible to reduce the amount of positional deviation between the attachment portion 77 of the lid member 71 and the through hole 27 of the inner barrel 22 in a state in which the first side surface 74 and the first guide surface 82 are in contact with each other. Thus, at the time of assembly of the sealing mechanism 70, the pin 79 can be easily inserted into the through hole 27 and the attachment portion 77 in the state in which the first side surface 74 and the first guide surface 82 are in contact with each other.

[0051] In a state in which the lid member 71 closes the opening 22a and the pin 79 is inserted into the attachment portion 77 of the lid member 71 and the through hole 27 of the inner barrel 22, a width W2 of a gap formed between the leg portion 76 and the second guide surface 84 in the direction parallel to the contact surface 22b may be, for example, 0.01 mm or more and 0.5 mm or less. When the width W2 is 0.01 mm or more, it is possible to suppress the guide portion 80 from hindering the smooth movement of the lid member 71 when the lid member 71 rotates around the rotational axis (the pin) 79 to one side and the other side. In addition, since the width W2 is 0.5 mm or less, it is possible to suppress the leg portion 76 from being displaced in a lateral direction (direction perpendicular to the second guide surface 84). Thus, rattling of the leg portion 76 in the lateral direction can be suppressed.

[0052] In the present embodiment, the first guide surface 82 faces the first side surface 74 when the lid member 71 closes the opening 22a as illustrated in Figs. 1 and 6. On the other hand, the first guide surface 82 does not face the first side surface 74 when the lid member 71 opens the opening 22a as illustrated in Fig. 2.

[0053] Next, an operation of the advancing and retracting mechanism 40 will be described with reference to Figs. 1 and 2.

[0054] When the user presses the push member 50 forward in the retracted state (Fig. 1), the writing member 12 moves forward via the rotary cam member 60. When the writing member 12 moves forward, the pen tip 13 pushes the lid member 71 forward against the spring force of the resilient member 90 to open the lid member 71. When the writing member 12 further moves forward, the pen tip 13 protrudes forward from the front end opening 20a. Even when the forward pressing of the push 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. Thus, the writing instrument 10 transitions from the retracted state to the protruding state.

[0055] In addition, in the protruding state (Fig. 2), when the user presses the push member 50 forward, the writing member 12 moves forward by a minute distance. When the forward pressing of the push member 50 is released, the writing member 12 moves rearward by the spring force of the first resilient member 42, and the pen tip 13 is retracted from the front end opening 20a. When the writing member 12 further moves rearward, the pen tip 13 is housed in the housing space S, and the lid member 71 closes the opening 22a of the barrel 20 (the inner barrel 22) by the spring force of the resilient member 90. Thus, the housing space S is sealed. As the housing space S is sealed, drying of the ink at the pen tip 13 is suppressed in the retracted state.

[0056] Next, a method for assembling the sealing mechanism 70 will be described with reference to Figs. 7 to 11. Figs. 7 to 11 are views for describing an example of an assembly process of the sealing mechanism 70.

[0057] Fig. 7 is a longitudinal sectional view illustrating the distal end part of the barrel 20 (the inner barrel 22) before the lid member 71, the resilient member 90, and the pin 79 are attached. The inner barrel 22 has the guide portion 80.

[0058] First, as illustrated in Figs. 8 and 9, the lid member 71 is disposed on the inner barrel 22. Specifically, the lid member 71 is disposed such that the closing surface 73 of the lid member 71 comes into contact with the contact surface 22b of the inner barrel 22, and the first side surface 74 of the lid member 71 comes into contact with the first guide surface 82 of the guide portion 80. At this time, the lid member 71 can be positioned by bringing the first side surface 74 into contact with the first guide surface 82. More specifically, the attachment portion 77 of the lid member 71 and the through hole 27 of the inner barrel 22 can be located substantially on a straight line by disposing the lid member 71 such that the first side surface 74 comes into contact with the first guide surface 82. Thus, the lid member 71 can be easily assembled to the inner barrel 22.

[0059] Next, the resilient member 90 is disposed as illustrated in Fig. 10. The first end portion 95 of the resilient member 90 is locked to the locking portion 78 of the lid member 71, and the resilient member 90 is disposed such that the coil portion 91 of the resilient member 90 and the through hole 27 are located substantially on a straight line. At this time, the second end portion 99 of the resilient member 90 is disposed in the recess 29 of the inner barrel 22.

[0060] Finally, as illustrated in Fig. 11, the pin 79 is disposed so as to penetrate the through hole 27, the attachment portion 77, and the coil portion 91. Specifically, the pin 79 is inserted into the through hole 27, the attachment portion 77, and the coil portion 91. At this time, since the lid member 71 is positioned by the first side surface 74 coming into contact with the first guide surface 82, the through hole 27, the attachment portion 77, and the coil portion 91 are located substantially on a straight line, so that the pin 79 can be smoothly inserted.

[0061] Fig. 12 is a view illustrating the lid member 71 and the guide portion 80 in the middle of opening and closing. As illustrated in Fig. 11, in a state in which the lid member 71 is attached to the inner barrel 22 by the pin 79 and the lid member 71 closes the opening 22a, the gap having the width W1 is formed between the first side surface 74 and the first guide surface 82. Thus, the first side surface 74 and the guide portion 80 are suppressed from coming into contact with each other during the opening and closing of the lid member 71 as illustrated in Fig. 12. Such a width W1 may be, for example, 0 mm or more and 1.0 mm or less.

[0062] The writing instrument 10 of the present embodiment includes: the barrel 20 having the opening 22a; the writing member having the pen tip 13; the advancing and retracting mechanism 40 that advances and retracts the pen tip 13 from the opening 22a; and the sealing mechanism 70 that seals the housing space S of the pen tip 13 in the retracted state of the pen tip 13, the sealing mechanism 70 having the lid member 71 that rotates around the rotational axis 79 to close and open the opening 22a, and the guide portion 80 that guides the lid member 71, the lid member 71 having the closing portion 72 having the closing surface 73 that closes the opening 22a and the first side surface 74, and the leg portion 76 that supports the closing portion 72, the guide portion 80 having a first guide surface 82 that faces the first side surface 74 when the lid member 71 closes the opening 22a and does not face the first side surface 74 when the lid member 71 opens the opening 22a.

[0063] In the writing instrument 10 of the present embodiment, the first side surface 74 is a surface facing the rotational axis 79 side, and the first guide surface 82 is a surface facing the side opposite to the rotational axis 79.

[0064] In the writing instrument 10 of the present embodiment, the lid member 71 has the two leg portions 76, the first side surface 74 is located between the two leg portions 76, and the guide portion 80 is located in the space between the two leg portions 76 when the lid member 71 closes the opening 22a.

[0065] According to the writing instrument 10, when the lid member 71 is assembled to the barrel 20, the lid member 71 can be positioned with respect to the barrel 20 by disposing the lid member 71 such that the first side surface 74 of the lid member 71 comes into contact with the first guide surface 82 of the guide portion 80. In particular, the attachment portion 77 of the lid member 71 and the through hole 27 of the inner barrel 22 can be located substantially on a straight line by disposing the lid member 71 such that the first side surface 74 comes into contact with the first guide surface 82. Thus, the lid member 71 can be easily assembled to the inner barrel 22. That is, the sealing mechanism 70 can be easily assembled.

[0066] In the writing instrument 10 of the present embodiment, the guide portion 80 has the second guide surface 84 that guides the leg portion 76.

[0067] According to the writing instrument 10, it is possible to suppress the leg portions 76 from being displaced in the lateral direction (the direction perpendicular to the second guide surface 84) during the opening and closing of the lid member 71. Thus, the rattling of the leg portion 76 in the lateral direction can be suppressed, and the lid member 71 can be stably opened and closed.

[0068] In the writing instrument 10 of the present embodiment, when the lid member 71 closes the opening 22a, the closing surface 73 comes into contact with the contact surface 22b surrounding the opening 22a, and the rotational axis 79 is located opposite to the housing space S with respect to the extended plane 22c of the contact surface 22b.

[0069] According to the writing instrument 10, the first side surface 74 and the guide portion 80 are suppressed from coming into contact with each other during the opening and closing of the lid member 71.

[0070] A modification of the present embodiment will be described with reference to Figs. 13 to 16. In the following description and drawings to be used in the following description, parts that can be configured in the same manner as the above-described embodiment may be represented by the same reference signs as the reference sings which have been used for the corresponding parts in the above-described embodiment, and the repeated description will be omitted.

[0071] Fig. 13 is a view illustrating a modification of the sealing mechanism 70, and is a perspective view illustrating the lid member 71 of the sealing mechanism 70 and the guide portion 80. Fig. 14 is a perspective view illustrating the guide portion 80 of the present modification. Fig. 15 is a view illustrating the lid member 71 and the guide portion 80 in the retracted state when viewed from the direction perpendicular to the contact surface 22b and the closing surface 73. Fig. 16 is a sectional view taken along line XVI-XVI in Fig. 15. Note that Fig. 15 corresponds to the line XV-XV in Fig. 16.

[0072] The sealing mechanism 70 of the present modification has two guide portions 80. Each of the two guide portions 80 has the first guide surface 82 and the second guide surface 84. The first guide surface 82 is located so as to face the first side surface 74 when the lid member 71 closes the opening 22a.

[0073] The second guide surface 84 of one guide portion 80 and the second guide surface 84 of the other guide portion 80 face each other. The second guide surface 84 of one guide portion 80 and the second guide surface 84 of the other guide portion 80 extend in parallel to each other.

[0074] The second guide surface 84 of one guide portion 80 faces one leg portion 76 of the lid member 71. The second guide surface 84 of the other guide portion 80 faces the other leg portion 76 of the lid member 71. The second guide surface 84 of the one guide portion 80 extends in parallel with the one leg portion 76 of the lid member 71. The second guide surface 84 of the other guide portion 80 extends in parallel with the other leg portion 76 of the lid member 71.

[0075] As illustrated in Figs. 14 and 15, the leg portion 76 of the lid member 71 is located in a space between the two guide portions 80 when the lid member 71 closes the opening 22a. In particular, in the present modification, the two leg portions 76 of the lid member 71 are located in the space between the two guide portions 80 when the lid member 71 closes the opening 22a. The leg portion 76 of the lid member 71 are located in a space between the second guide surface 84 of one guide portion 80 and the second guide surface 84 of the other guide portion 80 when the lid member 71 closes the opening 22a.

[0076] In the writing instrument 10 of the present modification, the sealing mechanism 70 has the two guide portions 80, and the leg portions 76 are located in the space between the two guide portions 80 when the lid member 71 closes the opening 22a.

[0077] Also with the above writing instrument 10, it is possible to suppress the leg portions 76 from being displaced in the lateral direction (the direction perpendicular to the second guide surface 84) during the opening and closing of the lid member 71. Thus, the rattling of the leg portion 76 in the lateral direction can be suppressed, and the lid member 71 can be stably opened and closed.

[0078] Such writing instrument 10 also suppresses the contact between the first side surface 74 and the guide portion 80 during the opening and closing of the lid member 71.

[0079] Note that, also with the writing instrument 10 of the present modification, when the lid member 71 is assembled to the barrel 20, the lid member 71 can be positioned with respect to the barrel 20 by disposing the lid member 71 such that the first side surface 74 of the lid member 71 comes into contact with the first guide surface 82 of the guide portion 80. In particular, the attachment portion 77 of the lid member 71 and the through hole 27 of the inner barrel 22 can be located substantially on a straight line by disposing the lid member 71 such that the first side surface 74 comes into contact with the first guide surface 82. Thus, the lid member 71 can be easily assembled to the inner barrel 22. That is, the sealing mechanism 70 can be easily assembled.

Claims

1. A writing instrument comprising: a barrel having an opening; a writing member having a pen tip; an advancing and retracting mechanism that advances and retracts the pen tip from the opening; and a sealing mechanism that seals a housing space of the pen tip in a retracted state of the pen tip, wherein the sealing mechanism has a lid member that rotates around a rotational axis to close and open the opening, and a guide portion that guides the lid member, the lid member has a closing portion having a closing surface that closes the opening and a first side surface, and a leg portion that supports the closing portion, and the guide portion has a first guide surface that faces the first side surface when the lid member closes the opening, and does not face the first side surface when the lid member opens the opening.

2. The writing instrument according to claim 1, wherein the first side surface is a surface facing a side of the rotational axis, and the first guide surface is a surface facing a side of the opening.

3. The writing instrument according to claim 2, wherein the lid member has two of the leg portions, the first side surface is located between the two leg portions, and the guide portion is located in a space between the two leg portions when the lid member closes the opening.

4. The writing instrument according to claim 2, wherein the sealing mechanism has two of the guide portions, and the leg portion is located in a space between the two guide portions when the lid member closes the opening.

5. The writing instrument according to claim 1, wherein the guide portion has a second guide surface that guides the leg portion.

6. The writing instrument according to any one of claims 1 to 5, wherein the closing surface comes into contact with a contact surface surrounding the opening when the lid member closes the opening, and the rotational axis is located opposite to the housing space with respect to an extended plane of the contact surface.

Images