Notebook

Abstract

[Problem] To miniaturize a mechanism, in a writing implement, for moving a writing member forward by a length longer than the movement length of a knock member. [Solution] A writing implement (10) including: a barrel (20) that has a front-end opening part (20a); a writing member (12) that is disposed inside the barrel; and an appearance / disappearance mechanism (40) that makes a tip end of the writing member appear from or disappear into the front-end opening part. The appearance / disappearance mechanism has: a first slit (81) that extends spirally around a central axis (A) of the barrel and that can rotate in a circumferential direction (dc); a second slit (82) that is disposed at a front side of the first slit, that extends spirally around the central axis, and that can rotate in the circumferential direction integrally with the first slit; a first engagement member (91) that is engaged with the first slit; and a second engagement member (92) that is engaged with the second slit. The movement length (L2) of the second engagement member in the axial direction (da) when the first slit and the second slit integrally rotate in the circumferential direction is longer than the movement length (L1) of the first engagement member in the axial direction.

Description

[Technical Field]

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

[0002] Conventionally, among writing instruments that include a barrel, a writing member arranged within the barrel, and a retraction mechanism that causes the writing member to appear and retract in response to the operation of a knock member, there is known a writing instrument that, when the knock member is operated, moves the writing member forward a distance greater than the distance traveled by the knock member.

[0003] JP4642782B describes a writing instrument equipped with an advance / retract mechanism having an output device that moves a longer distance than the input device. The advance / retract mechanism includes a first cam having a first inclined surface and a second cam having a second inclined surface. The second cam is configured to push an output device assembly having a pen tip forward. In the retracted position, the first cam and the second cam are arranged so that the first and second inclined surfaces face each other and contact each other. When a user pushes the first cam forward, the first cam moves forward while rotating relative to the barrel. Meanwhile, the second cam does not rotate relative to the barrel but is pushed forward by the first cam. When the first cam rotates 180 degrees relative to the barrel, the tip of the first inclined surface of the first cam and the tip of the second inclined surface of the second cam abut axially, and the second cam is positioned in the advance position. During this process, the forward movement distance of the second cam is greater than the forward movement distance of the first cam. Therefore, with this writing implement, when the user presses the first cam forward, the distance the pen tip moves forward is greater than the distance the first cam moves forward.

[0004] In conventional writing instruments, which move a writing element forward by a distance greater than the distance traveled by the knock element when the knock element is operated, the mechanism for achieving this function is large. This results in an increase in the size and weight of the writing element. Furthermore, in the writing instrument disclosed in JP4642782B, the tip of the first inclined surface of the first cam and the tip of the second inclined surface of the second cam abut in the forward position. At this time, the spring force of the spring biasing the output device assembly backward is received at a single point between the tips of the first and second inclined surfaces. In this case, large stress acts on the tips of the first and second inclined surfaces, potentially damaging the tips of the first and second inclined surfaces. Summary of the Invention

[0005] The present invention has been made in consideration of these points, and aims to miniaturize a mechanism in a writing instrument for moving a writing member forward a distance greater than the movement distance of the knock member.

[0006] The writing instrument according to the present invention comprises: [1] A writing instrument comprising a barrel having a front end opening, a writing element disposed within the barrel, and a retraction mechanism for causing the tip of the writing element to protrude and retract from the front end opening, The retractable mechanism is a first slit extending spirally around the central axis of the barrel and rotatable in a circumferential direction; a second slit disposed in front of the first slit, extending spirally around the central axis, and rotatable in the circumferential direction integrally with the first slit; a first engagement member that engages with the first slit; a second engagement member that engages with the second slit, The writing implement is such that when the first slit and the second slit rotate together in the circumferential direction, the axial movement distance of the second engagement member is greater than the axial movement distance of the first engagement member.

[0007] The writing instrument according to the present invention comprises: [2] The writing instrument according to [1], wherein the angle between the rear wall of the second slit and the axial direction is smaller than the angle between the front wall of the first slit and the axial direction.

[0008] The writing instrument according to the present invention comprises: [3] A rotating member is disposed in the shaft cylinder, The writing implement according to [1] or [2], wherein the first slit and the second slit are provided in the rotating member.

[0009] The writing instrument according to the present invention comprises: [4] The writing instrument according to any one of [1] to [3], wherein at least a portion of the second slit overlaps with at least a portion of the first slit when viewed from the axial direction.

[0010] The writing instrument according to the present invention comprises: [5] The writing instrument according to any one of [1] to [4], wherein at least a portion of the second slit overlaps with at least a portion of the first slit when viewed from the circumferential direction.

[0011] The writing instrument according to the present invention comprises: [6] An inner cylinder is provided which is fixed to the barrel cylinder and has a first elongated hole extending in the axial direction and a second elongated hole extending in the axial direction; the first engagement member engages with the first elongated hole, The writing implement according to any one of [1] to [5], wherein the second engagement member engages with the second elongated hole.

[0012] The writing instrument according to the present invention comprises: [7] The writing implement according to [6], wherein the portion of the first engagement member facing the wall surface of the first elongated hole is flat.

[0013] The writing instrument according to the present invention comprises: [8] The writing implement according to [6] or [7], wherein the portion of the second engagement member facing the wall surface of the second slot is flat. [Effects of the Invention]

[0014] According to the present invention, it is possible to reduce the size of the mechanism in the writing instrument for moving the writing member forward by a distance greater than the moving distance of the knock member. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram for explaining one embodiment of the present invention, and is a vertical cross-sectional view showing an example of a writing implement in an immersed state. [Figure 2] FIG. 2 is an enlarged longitudinal cross-sectional view showing the rear portion of the writing implement. [Figure 3] FIG. 3 is a vertical cross-sectional view showing the writing implement in a protruding state. [Figure 4] FIG. 4 is an exploded view showing the stroke augmentation mechanism of the writing implement. [Figure 5] FIG. 5 is a perspective view of the stroke increase mechanism in an assembled state. [Figure 6] FIG. 6 is a diagram for explaining the operation of the stroke increasing mechanism. [Figure 7] FIG. 7 is a diagram for explaining the operation of the stroke increasing mechanism. [Figure 8] FIG. 8 is a diagram for explaining the operation of the stroke increasing mechanism. [Figure 9] FIG. 9 is a diagram for explaining the operation of the stroke increasing mechanism. DETAILED DESCRIPTION OF THE INVENTION

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

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

[0018] In this specification, the direction in which the central axis A of the writing instrument 10 extends (longitudinal direction) is referred to as the axial direction da, the direction perpendicular to the axial direction da is referred to as the radial direction, and the direction along the circumference around the central axis A is referred to as the circumferential direction dc. Along the axial direction da, the side toward the pen tip is referred to as the front, and the side opposite the pen tip is referred to as the rear. Also, along the radial direction, the side closer to the central axis A is referred to as the inside or inner side, and the side away from the central axis A is referred to as the outside or outer side.

[0019] Figure 1 is a diagram for explaining one embodiment of the present invention, and is a vertical cross-sectional view showing an example of a writing instrument 10 in a immersed state, Figure 2 is a vertical cross-sectional view showing an enlarged rear portion of the writing instrument 10, and Figure 3 is a vertical cross-sectional view showing the writing instrument 10 in a protruding state.

[0020] The writing instrument 10 of this embodiment includes a writing member 12, a barrel 20, and a retractable mechanism 40. The writing instrument 10 extends along a central axis A. The writing member 12 is a member that writes on a writing surface, such as paper. The writing member 12 is housed within the barrel 20. Examples of the writing member 12 include components used in ballpoint pens, fountain pens, markers, mechanical pencils, stylus pens, and the like. In this embodiment, an example will be described in which the writing instrument 10 is a fountain pen. The writing member 12 of this embodiment includes ink, a barrel that houses the ink, a nib 13 provided at the front end, a first receiving portion 14 that receives the resilient force of a resilient member 42 (described below), and a protruding portion 15 that protrudes radially outward. The first receiving portion 14 is a forward-facing surface of a step formed on the outer surface of the writing member 12.

[0021] The retractable mechanism 40 is a mechanism for alternately switching the writing instrument 10 between a protruding state in which the nib 13 protrudes from the front end opening 20a of the barrel 20 and a retracted state in which the nib 13 is retracted from the front end opening 20a.

[0022] The barrel 20 includes a front barrel 21, a rear barrel 31 disposed behind the front barrel 21, and a tip member 34 disposed in front of the front barrel 21. The central axis of the barrel 20 coincides with the central axis A of the writing instrument 10. A front end opening 20a is provided at the front end of the barrel 20, through which the nib 13 can pass. In this embodiment, the front end opening 20a is formed at the front end of the tip member 34.

[0023] The front shaft 21 is a generally cylindrical member intended to be grasped with the fingers when a user writes with the writing instrument 10. The front shaft 21 includes an inner shaft 22, an outer shaft 26 disposed radially outward of the inner shaft 22, and a first connecting member 28. The inner shaft 22 houses the front portion of the writing member 12. The inner surface of the inner shaft 22 is formed with a second receiving portion 23 that receives the resilient force of a resilient member 42 (described below), and a groove 24 that engages with the protrusion 15 of the writing member 12. The second receiving portion 23 is the rearward-facing surface of a step formed on the inner surface of the inner shaft 22. The groove 24 extends in the axial direction da. By positioning the protrusion 15 of the writing member 12 within the groove 24, the writing member 12 is supported relative to the barrel 20 so as to be movable in the axial direction da but not rotatable in the circumferential direction. The inner shaft 22 is formed, for example, from resin.

[0024] Outer shaft 26 is a component visible to the user and is a component that the user grasps with their fingers when writing with writing instrument 10. Therefore, outer shaft 26 is formed of an appropriate material, taking into consideration design and ease of grip by the user. For example, outer shaft 26 may be formed of resin, elastomer, metal, wood, or the like. First connecting member 28 is a component that forms a connection with rear shaft 31. First connecting member 28 is fixed to the rear end of at least one of inner shaft 22 and outer shaft 26. For example, first connecting member 28 may be fixed to the rear end of at least one of inner shaft 22 and outer shaft 26 by adhesive bonding. First connecting member 28 is formed of, for example, resin, metal, or the like. Note that the illustrated example is not limiting, and inner shaft 22 and outer shaft 26 may be formed of a single component. Furthermore, inner shaft 22, outer shaft 26, and first connecting member 28 may be formed of a single component. In other words, the entire front shaft 21 may be formed integrally.

[0025] The rear axle 31 is a member having a generally cylindrical shape and is arranged rearward of the front axle 21. The rear axle 31 includes a rear axle main body 32 and a second connecting member 33. The rear axle main body 32 is a member having a generally cylindrical shape. The rear axle main body 32 is formed, for example, from resin, metal, wood, etc. The second connecting member 33 is a member that forms a connecting portion with the front axle 21. The second connecting member 33 is fixed to the front end portion of the rear axle main body 32. The second connecting member 33 is formed, for example, from resin, metal, etc. The rear axle 31 is connected to the front axle 21 by attaching the front end portion of the rear axle 31 to the rear end portion of the front axle 21. In particular, the rear axle 31 is connected to the front axle 21 by attaching the second connecting member 33 to the first connecting member 28. For example, a female thread formed on the inner surface of second connecting member 33 is threadedly engaged with a male thread formed on the outer periphery of first connecting member 28, thereby connecting rear axle 31 to front axle 21. Note that rear axle main body 32 and second connecting member 33 may be configured as a single member.

[0026] Tip member 34 is a member that forms the tip portion of barrel 20. Tip member 34 has a generally truncated cone shape, and its outer diameter decreases toward the front. The rear end of tip member 34 is attached to the front end of front axle 21, thereby connecting tip member 34 to front axle 21. Tip member 34 is connected to front axle 21 by, for example, press-fitting, bonding, or screwing in a threaded portion.

[0027] A lid 17 is provided at the front of the barrel 20. The lid 17 seals the storage space for the nib 13 in the retracted state and allows the nib 13 to protrude in the extended state. The lid 17 is biased by a resilient member 18 in a direction that seals the storage space for the nib 13. The resilient member 18 is, for example, a torsion spring. In this embodiment, in the retracted state, the resilient force of the resilient member 18 closes the lid 17, sealing the storage space for the nib 13 (see FIG. 1). This prevents the ink on the nib 13 from drying out. When transitioning from the retracted state to the extended state, the nib 13 moves forward and pushes the lid 17 forward, opening the lid 17, and the nib 13 protrudes forward from the front-end opening 20a of the barrel 20 (see FIG. 3). In this extended state, writing with the writing instrument 10 becomes possible.

[0028] The retractable mechanism 40 is a mechanism for alternately switching the writing instrument 10 between a protruding state and a retracted state. The retractable mechanism 40 of this embodiment includes a resilient member 42 and a stroke increasing mechanism 50. The resilient member 42 is, for example, a coil spring. The resilient member 42 is disposed in a compressed state between the first receiving portion 14 of the writing instrument 12 and the second receiving portion 23 of the barrel 20 (front barrel 21). Therefore, the resilient member 42 constantly biases the writing instrument 12 rearward relative to the barrel 20.

[0029] In this embodiment, the writing instrument 10 is configured so that, when the user presses the knock member 60 forward, the distance the writing member 12 moves forward along the axial direction da is greater than the distance the knock member 60 moves forward along the axial direction da. The stroke increase mechanism 50 that achieves this function will be described primarily with reference to Figures 2, 4, and 5. Figure 2 shows an enlarged view of the stroke increase mechanism 50. Figure 4 is an exploded view of the stroke increase mechanism 50, and Figure 5 is a perspective view of the stroke increase mechanism 50 in an assembled state. The resilient member 52 is not shown in Figure 4.

[0030] The stroke increasing mechanism 50 of this embodiment includes a knock member 60, an inner cylinder 70, a rotating member 80, a first engaging member 91, a second engaging member 92, a sliding member 96, a resilient member 52, and a restricting member 54. Each of the components constituting the stroke increasing mechanism 50 will be described below.

[0031] The knock member 60 is a member intended to be operated by a user. The knock member 60 includes an operating portion 62 and a front portion 64 located in front of the operating portion 62. The operating portion 62 is a portion that is pressed by the user's finger or the like. In the retracted and extended states, the rear end of the operating portion 62 protrudes rearward from the rear end of the barrel 20 (rear barrel 31). The front portion 64 has a radial dimension larger than the radial dimension of the operating portion 62. The inner diameter of the rear end of the barrel 20 is large enough for the operating portion 62 to pass through but not the front portion 64. Therefore, the knock member 60 does not slip rearward from the rear end of the barrel 20. A recess 66 is formed on the front surface of the front portion 64. In this embodiment, in the retracted state, at least a portion of a rearward protruding portion 99 (described later) of the slide member 96 is located within the recess 66. Note that, as shown in FIG. 4, the knock member 60 may be divided into two parts, front and rear.

[0032] Holes 68 are provided in the side wall of the front portion 64. The holes 68 are through-holes that penetrate the side wall of the front portion 64 in the radial direction. In this embodiment, two holes 68 are provided at an angular pitch of 180 degrees in the circumferential direction dc. The holes 68 have the function of holding the first engagement member 91.

[0033] Inner tube 70 is a substantially cylindrical member, and is fixed to barrel tube 20. For example, inner tube 70 is fixed to barrel tube 20 by threading a male thread portion formed on the outer periphery of the rear end of inner tube 70 into a female thread portion formed on the inner periphery of the rear end of rear barrel 31 (rear barrel body 32). In this embodiment, decorative member 36 is connected to the rear end of inner tube 70. Decorative member 36 is a member provided to improve the design of writing instrument 10. Decorative member 36 is fixed to inner tube 70 by threading a female thread portion formed on the inner periphery of decorative member 36 into a male thread portion formed on the outer periphery of the rear end of inner tube 70.

[0034] The inner cylinder 70 has a first elongated hole 71 extending in the axial direction da and a second elongated hole 72 extending in the axial direction da. Fig. 6 shows the first elongated hole 71 and the second elongated hole 72 of the inner cylinder 70 in the retracted state, as well as a first slit 81 and a second slit 82 (described below) of the rotating member 80, viewed from the outside in the radial direction. The elongated holes 71, 72 and the slits 81, 82 are formed in different members, but Fig. 6 shows the elongated holes 71, 72 and the slits 81, 82 overlapping each other.

[0035] The first elongated hole 71 and the second elongated hole 72 are both through holes that penetrate the side wall of the inner tube 70 in the radial direction. The first elongated hole 71 and the second elongated hole 72 each extend linearly along the axial direction da. In this embodiment, two first elongated holes 71 are provided at an angular pitch of 180 degrees in the circumferential direction dc. Two second elongated holes 72 are provided at an angular pitch of 180 degrees in the circumferential direction dc. The first elongated holes 71 and the second elongated holes 72 are aligned in the circumferential direction dc. The length of the second elongated holes 72 along the axial direction da is greater than the length of the first elongated holes 71 along the axial direction da. The front end of the second elongated holes 72 is located forward of the front end of the first elongated hole 71. The rear end of the second elongated hole 72 is located forward of the rear end of the first elongated hole 71. When viewed along the circumferential direction dc, at least a portion of the second elongated hole 72 overlaps with at least a portion of the first elongated hole 71. In particular, when viewed along the circumferential direction dc, a rear portion of the second elongated hole 72 overlaps a front portion of the first elongated hole 71. A first engagement member 91 engages with the first elongated hole 71, and a second engagement member 92 engages with the second elongated hole 72. The first elongated hole 71 is surrounded by a side wall surface 71a and an end wall surface 71b. The second elongated hole 72 is surrounded by a side wall surface 72a and an end wall surface 72b. The side wall surfaces 71a, 72a are flat surfaces extending along the axial direction da. The end wall surfaces 71b, 72b are curved surfaces having an arc-like shape.

[0036] The rotating member 80 is a substantially cylindrical member and is rotatable in the circumferential direction dc relative to the barrel 20. The rotating member 80 has a first slit 81 that extends spirally around the central axis A and a second slit 82 that extends spirally around the central axis A. The first slit 81 and the second slit 82 both penetrate the side wall of the rotating member 80 in the radial direction. As will be described later, a first engaging member 91 engages with the first slit 81, and a second engaging member 92 engages with the second slit 82. The rotating member 80 rotates to one side in the circumferential direction dc as the knock member 60 moves forward.

[0037] The first slits 81 and the second slits 82 are rotatable integrally in the circumferential direction dc when the rotating member 80 rotates. The term "integrally" rotatable between the first slits 81 and the second slits 82 means that when the first slits 81 rotate by a certain angle in the circumferential direction dc, the second slits 82 also rotate by the same angle in the same direction in the circumferential direction dc. In the present embodiment, both the first slits 81 and the second slits 82 are provided in one rotating member 80. This allows the first slits 81 and the second slits 82 to rotate integrally in the circumferential direction dc. However, this is not limited thereto, and the stroke increasing mechanism 50 may include two rotating members 80, with the first slits 81 provided in one rotating member 80 and the second slits 82 provided in the other rotating member 80. In this case, the first slits 81 and the second slits 82 are rotatable integrally in the circumferential direction dc when the one rotating member 80 and the other rotating member 80 are configured to be rotatable integrally in the circumferential direction dc.

[0038] In this embodiment, two first slits 81 are provided at an angular pitch of 180 degrees in the circumferential direction dc. Furthermore, two second slits 82 are provided at an angular pitch of 180 degrees in the circumferential direction dc. The first slits 81 and the second slits 82 are aligned in the circumferential direction dc. The length of the second slits 82 along the axial direction da is greater than the length of the first slits 81 along the axial direction da. The front end of the second slits 82 is located forward of the front end of the first slits 81. Furthermore, the rear end of the second slits 82 is located forward of the rear end of the first slits 81.

[0039] When viewed along the axial direction da, at least a portion of the second slit 82 overlaps with at least a portion of the first slit 81. In particular, when viewed along the axial direction da, a rear portion of the second slit 82 overlaps with a front portion of the first slit 81. By arranging the first slit 81 and the second slit 82 in this manner, the space required for arranging the first slit 81 and the second slit 82 can be reduced. This allows the stroke increase mechanism 50 to be made smaller. This also allows the writing instrument 10 to be made smaller.

[0040] When viewed along the circumferential direction dc, at least a portion of the second slit 82 overlaps with at least a portion of the first slit 81. In particular, when viewed along the circumferential direction dc, a rear portion of the second slit 82 overlaps with a front portion of the first slit 81. By arranging the first slit 81 and the second slit 82 in this manner, the space required for arranging the first slit 81 and the second slit 82 can be reduced. This allows the stroke increase mechanism 50 to be made smaller. This also allows the writing instrument 10 to be made smaller.

[0041] The first slit 81 has a front wall 81a and a rear wall 81b that face each other. The front wall 81a is located forward of the rear wall 81b. The front wall 81a and the rear wall 81b extend in directions that are inclined with respect to both the axial direction da and the circumferential direction dc. A bulging portion 81c that bulges forward is provided at the front end of the rear wall 81b. In the protruding state (see FIG. 9 ), the bulging portion 81c functions as a detent that prevents the first engagement member 91 from moving toward the rear end of the first slit 81 due to the elastic force of the elastic member 42. The second slit 82 has a front wall 82a and a rear wall 82b that face each other. The front wall 82a is located forward of the rear wall 82b. The front wall 82a and the rear wall 82b extend in directions that are inclined with respect to both the axial direction da and the circumferential direction dc. A bulging portion 82c that bulges forward is provided at the front end of the rear wall 82b. In the protruding state, the bulging portion 82c has a function of preventing the second engaging member 92 from moving toward the rear end side of the second slit 82 due to the resilient force of the resilient member 42.

[0042] In this embodiment, the angle θ2 between the rear wall 82b of the second slit 82 and the axial direction da is smaller than the angle θ1 between the front wall 81a of the first slit 81 and the axial direction da. The angle θ1 between the front wall 81a and the axial direction da refers to the smaller of the two angles formed by the front wall 81a and a line extending in the axial direction da when viewed from the radial direction as shown in FIGS. 6 to 9 . Furthermore, if the angle between the front wall 81a and the axial direction da is not constant along the entire length of the front wall 81a, the angle between the front wall 81a and the axial direction da can be measured at multiple locations on the front wall 81a, and the arithmetic mean value of the measured values ​​can be used as the angle θ1. For example, five points are measured forward of the center of the front wall 81a and five points are measured rearward of the center of the front wall 81a, for a total of 10 points. The angles between the front wall 81a and the axial direction da at these 10 points can be measured, and the arithmetic mean value of the measured values ​​can be used as the angle θ1. The same applies to the angle θ2.

[0043] The rear end of the rotating member 80 protrudes rearward from the rear end of the barrel 20 (rear barrel 31), and crown 38 is fixed to the rear end of the rotating member 80. Crown 38 is rotatable integrally with the rotating member 80. In the retracted state, when the user presses the knock member 60 forward, the rotating member 80 rotates to one side in the circumferential direction dc and assumes the protruding state. In this embodiment, when the user rotates crown 38 to the other side in the circumferential direction dc in the protruding state, the rotating member 80 together with crown 38 rotates to the other side in the circumferential direction dc and assumes the retracted state. The operation of returning the writing instrument 10 from the protruding state to the retracted state will be described in detail below.

[0044] The slide member 96 is a member disposed in front of the knock member 60. The slide member 96 includes a front portion 97 and a rearward protruding portion 99 located rearward of the front portion 97 and protruding rearward. A hole 98 is provided in the side wall of the front portion 97. The hole 98 is a through-hole that radially penetrates the side wall of the front portion 97. In this embodiment, two hole portions 98 are provided at an angular pitch of 180 degrees in the circumferential direction dc. The hole portions 98 have the function of holding the second engagement member 92. The slide member 96 is configured to move back and forth integrally with the second engagement member 92.

[0045] The first engagement member 91 is a rod-shaped member held by the knock member 60. The first engagement member 91 can move back and forth integrally with the knock member 60. The knock member 60 is disposed radially penetrating the hole 68 of the knock member 60. In particular, the knock member 60 has two hole portions 68, and the first engagement member 91 is disposed penetrating the two hole portions 68 of the knock member 60. One end of the first engagement member 91 engages with one of the two first slits 81 of the rotating member 80 and one of the two first elongated holes 71 of the inner cylinder 70. The other end of the first engagement member 91 engages with the other of the two first slits 81 of the rotating member 80 and the other of the two first elongated holes 71 of the inner cylinder 70. Specifically, one end of the first engagement member 91 radially passes through one of the two first slits 81 of the rotating member 80, and one end edge of the first engagement member 91 is located inside one of the two first elongated holes 71 of the inner cylinder 70. The other end of the first engagement member 91 radially passes through the other of the two first slits 81 of the rotating member 80, and the other end edge of the first engagement member 91 is located inside the other of the two first elongated holes 71 of the inner cylinder 70. As a result, when the rotating member 80 rotates in the circumferential direction dc relative to the inner cylinder 70, each end of the first engagement member 91 moves within the first elongated hole 71 and the first slit 81 so as to always be located in a portion where the first elongated hole 71 and the first slit 81 overlap when viewed from the radial direction.

[0046] The second engagement member 92 is a rod-shaped member and is held by the slide member 96. The second engagement member 92 can move back and forth integrally with the slide member 96. The slide member 96 is disposed so as to radially penetrate a hole 98 of the slide member 96. In particular, the slide member 96 has two hole portions 98, and the second engagement member 92 is disposed so as to penetrate the two hole portions 98 of the slide member 96. One end of the second engagement member 92 engages with one of the two second slits 82 of the rotating member 80 and one of the two second elongated holes 72 of the inner cylinder 70. The other end of the second engagement member 92 engages with the other of the two second slits 82 of the rotating member 80 and the other of the two second elongated holes 72 of the inner cylinder 70. Specifically, one end of the second engagement member 92 radially passes through one of the two second slits 82 of the rotating member 80, and one edge of the second engagement member 92 is located inside one of the two second elongated holes 72 of the inner tube 70. The other end of the second engagement member 92 radially passes through the other of the two second slits 82 of the rotating member 80, and the other edge of the second engagement member 92 is located inside the other of the two second elongated holes 72 of the inner tube 70. As a result, when the rotating member 80 rotates in the circumferential direction dc relative to the inner tube 70, each end of the second engagement member 92 moves within the second elongated hole 72 and the second slit 82 so as to always be located in a portion where the second elongated hole 72 and the second slit 82 overlap when viewed from the radial direction.

[0047] The first engagement member 91 has a first abutment surface 91a at a portion facing the side wall surface 71a of the first elongated hole 71. The second engagement member 92 has a second abutment surface 92a at a portion facing the side wall surface 72a of the second elongated hole 72. In this embodiment, the abutment surfaces 91a, 92a are flat. Because the abutment surfaces 91a, 92a are flat, the area of ​​the abutment portion between the abutment surfaces 91a, 92a and the side wall surfaces 71a, 72a is increased, and the pressure acting on the abutment surfaces 91a, 92a is reduced. Therefore, wear of the abutment surfaces 91a, 92a when the abutment surfaces 91a, 92a slide against the side wall surfaces 71a, 72a can be suppressed.

[0048] However, the first engaging member 91 and the second engaging member 92 may have a circular cross-sectional shape along their entire length. In this case, the engaging members 91 and 92 can easily rotate about their axes, allowing the engaging members 91 and 92 to roll relative to the side wall surfaces 71 a and 72 a. This reduces friction between the engaging members 91 and 92 and the side wall surfaces 71 a and 72 a.

[0049] A resilient member 52 is disposed between the first engagement member 91 and the slide member 96. The resilient member 52 is, for example, a coil spring. The resilient member 52 is disposed in a compressed state between the first engagement member 91 and the slide member 96. Therefore, the resilient member 52 constantly biases the first engagement member 91 rearward relative to the slide member 96.

[0050] The restricting member 54 is disposed in front of the rotating member 80 and restricts the forward movement of the rotating member 80. The restricting member 54 is not fixed to the barrel 20 and is capable of forward and backward movement in the axial direction da and rotation in the circumferential direction dc. However, the forward movement of the restricting member 54 is restricted by the second connecting member 33 of the rear axle 31, and the rearward movement of the restricting member 54 is restricted by the rotating member 80. When the rotating member 80 moves forward, the rotating member 80 abuts against the restricting member 54, and the restricting member 54 abuts against the second connecting member 33, thereby preventing the rotating member 80 from moving further forward. From the perspective of reducing friction between the rotating member 80 and the restricting member 54 and between the restricting member 54 and the barrel 20 (rear axle 31), the restricting member 54 is preferably made of a material that is unlikely to generate large friction (highly lubricious). Examples of such materials that can be used include polyacetal, fluororesin, and PEEK (polyether ether ketone).

[0051] Next, the extension / retraction operation of the writing instrument 10 and the operation of the stroke increasing mechanism 50 will be described. Figures 6 to 9 are diagrams for explaining the operation of the stroke increasing mechanism 50. In Figures 6 to 9, the first elongated hole 71 and the second elongated hole 72 of the inner tube 70, the first slit 81 and the second slit 82 of the rotating member 80, the first engaging member 91 and the second engaging member 92 are shown overlapping when viewed from the outside in the radial direction. As described above, when the rotating member 80 rotates in the circumferential direction dc relative to the inner tube 70, each end of the first engaging member 91 moves within the first elongated hole 71 and the first slit 81 so as to always be located in the area where the first elongated hole 71 and the first slit 81 overlap when viewed from the radial direction. Furthermore, when the rotating member 80 rotates in the circumferential direction dc relative to the inner tube 70, each end of the second engaging member 92 moves within the second elongated hole 72 and the second slit 82 so that it is always positioned in the area where the second elongated hole 72 and the second slit 82 overlap when viewed radially.

[0052] In the retracted state, the writing element 12 is biased rearward by the resilient force of the resilient member 42. This also biases the second engagement member 92, the slide member 96, the resilient member 52, the first engagement member 91, and the knock member 60 rearward. At this time, the first engagement member 91 is positioned at the rearmost portion of the first elongated hole 71 and the first slit 81, and the second engagement member 92 is positioned at the rearmost portion of the second elongated hole 72 and the second slit 82 (see FIG. 6). In this state, the pen tip 13 is retracted from the front-end opening 20a. The resilient force of the resilient member 18 closes the cover 17, sealing the storage space for the pen tip 13. The resilient force of the resilient member 42 is greater than that of the resilient member 52. Therefore, in the retracted state, the resilient force of the resilient member 42 compresses the resilient member 52.

[0053] When the user presses the knock member 60 forward, the knock member 60 moves forward against the elastic force of the elastic member 42. The first engagement member 91 is pressed by the knock member 60 and moves forward (see FIG. 7). Each end of the first engagement member 91 moves forward within the first elongated hole 71 of the inner tube 70. The inner tube 70 is fixed to the barrel 20 (rear barrel 31) and does not rotate relative to the barrel 20. Therefore, the knock member 60 and the first engagement member 91 move in the axial direction da relative to the barrel 20, but do not move in the circumferential direction dc.

[0054] When the first engagement member 91 moves forward, the first engagement member 91 presses against the front wall 81a of the first slit 81 of the rotation member 80. Because the front wall 81a extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc, a component force is generated in the front wall 81a that presses the front wall 81a toward one side in the circumferential direction dc. This component force causes the rotation member 80 to rotate toward one side in the circumferential direction dc.

[0055] As the rotating member 80 rotates in the circumferential direction dc, the rear wall 82b of the second slit 82 of the rotating member 80 presses the second engagement member 92. As described above, the inner tube 70 does not rotate relative to the barrel 20. Therefore, the second engagement member 92, which is engaged with the second elongated hole 72 of the inner tube 70, moves in the axial direction da relative to the barrel 20, but does not move in the circumferential direction dc. The rear wall 82b extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc. Therefore, a component force that presses the second engagement member 92 forward is generated in the second engagement member 92. This component force causes the second engagement member 92 to move forward. As a result, the writing member 12 is pressed forward by the second engagement member 92. At this time, the pen tip 13, which has moved forward, presses the cover portion 17 forward, causing the cover portion 17 to open.

[0056] In this embodiment, both the first slit 81 and the second slit 82 are provided in one rotating member 80. This allows the first slit 81 and the second slit 82 to rotate integrally in the circumferential direction dc.

[0057] When the user presses the knock member 60 further forward, the knock member 60 moves further forward. As a result, the first engagement member 91 is positioned at the forefront of the first elongated hole 71 and the first slit 81 (see FIG. 8). Furthermore, as the rotating member 80 rotates further toward one side in the circumferential direction dc, the second engagement member 92 is also positioned at the forefront of the second elongated hole 72 and the second slit 82. At this time, the pen tip 13 protrudes forward from the front-end opening 20a of the barrel 20.

[0058] When the user releases the pressure on the knock member 60, the writing member 12 moves rearward due to the elastic force of the elastic member 42. This causes the second engagement member 92 to move rearward, and the second engagement member 92 presses the rear wall 82b of the second slit 82 rearward (see FIG. 9). A bulging portion 82c that bulges forward is provided at the front end of the rear wall 82b. This bulging portion 82c prevents the second slit 82 from rotating to the other side in the circumferential direction dc. Furthermore, the elastic force of the elastic member 52 causes the first engagement member 91 to move rearward. This causes the first engagement member 91 to press the rear wall 81b of the first slit 81 rearward. A bulging portion 81c that bulges forward is provided at the front end of the rear wall 81b. This bulging portion 81c prevents the first slit 81 from rotating to the other side in the circumferential direction dc. Therefore, even if the user releases the pressure on the knock member 60, the rotating member 80 does not rotate to the other side in the circumferential direction dc, and the first engaging member 91 and the second engaging member 92 do not move rearward from this state. As a result, the pen tip 13 is maintained in a state where it protrudes forward from the front-end opening 20a of the barrel 20 (see FIG. 3).

[0059] 9, the positions of the first engagement member 91 and the second engagement member 92 in the immersed state are indicated by dashed lines. In this embodiment, the angle θ2 between the rear wall 82b of the second slit 82 and the axial direction da is smaller than the angle θ1 between the front wall 81a of the first slit 81 and the axial direction da. As a result, when the first slit 81 and the second slit 82 rotate integrally in the circumferential direction dc, the movement distance L2 of the second engagement member 92 in the axial direction da is greater than the movement distance L1 of the first engagement member 91 in the axial direction da. Therefore, when a user presses the knock member 60, the movement distance (stroke) of the writing member 12 along the axial direction da is greater than the movement distance (stroke) of the knock member 60 along the axial direction da.

[0060] When transitioning writing instrument 10 from the extended state (see FIG. 3) to the retracted state (see FIG. 1), the user rotates crown 38 to the other side in circumferential direction dc, causing rotation member 80, which is fixed to crown 38, to rotate to the other side in circumferential direction dc. As a result, first engagement member 91 moves over bulging portion 81c of first slit 81. Similarly, second engagement member 92 moves over bulging portion 82c of second slit 82. Thereafter, first engagement member 91 and second engagement member 92 move rearward due to the resilient force of resilient member 42. At this time, first engagement member 91 moves to the rear portion of first slit 81 and presses against rear wall 81b of first slit 81. Furthermore, second engagement member 92 moves to the rear portion of second slit 82 and presses against rear wall 82b of second slit 82. Because the rear walls 81b, 82b extend in a direction inclined relative to both the axial direction da and the circumferential direction dc, a component force is generated in the rear walls 81b, 82b that presses the rear walls 81b, 82b toward the other side in the circumferential direction dc. This component force causes the rotating member 80 to rotate toward the other side in the circumferential direction dc. As the first engaging member 91 and the second engaging member 92 move rearward, the writing member 12 also moves rearward and retracts from the front-end opening 20a of the barrel 20. The resilient force of the resilient member 18 then closes the cover 17, sealing the storage space for the nib 13.

[0061] The writing instrument 10 of this embodiment is a writing instrument 10 comprising a barrel 20 having a front end opening 20a, a writing member 12 arranged in the barrel 20, and a retraction mechanism 40 that causes the tip of the writing member 12 to protrude and retract from the front end opening 20a, wherein the retraction mechanism 40 has a first slit 81 that extends spirally around the central axis A of the barrel 20 and is rotatable in the circumferential direction dc, a second slit 82 that is arranged in front of the first slit 81, extends spirally around the central axis A, and is rotatable in the circumferential direction dc integrally with the first slit 81, a first engagement member 91 that engages with the first slit 81, and a second engagement member 92 that engages with the second slit 82, and when the first slit 81 and the second slit 82 rotate integrally in the circumferential direction dc, the axial movement distance L2 of the second engagement member 92 in the axial direction da is greater than the axial movement distance L1 of the first engagement member 91 in the axial direction da.

[0062] In this writing instrument 10, the axial movement distance L2 of the second engagement member 92 is greater than the axial movement distance L1 of the first engagement member 91. Therefore, when a user presses the knock member 60, the movement distance of the writing member 12 along the axial direction da can be greater than the movement distance of the knock member 60 along the axial direction da. Furthermore, this mechanism is configured with the first slit 81 and the second slit 82, which extend spirally around the central axis A and are rotatable in the circumferential direction dc. Therefore, a desired stroke ratio can be achieved by adjusting the position, angle, and spacing of the first slit 81 and the second slit 82. This increases the design flexibility of the mechanism for making the movement distance of the writing member 12 greater than the movement distance of the knock member 60. This allows for a more compact mechanism for moving the writing member 12 forward by a distance greater than the movement distance of the knock member 60.

[0063] Furthermore, in the writing instrument 10 of this embodiment, the engaging members 91, 92 and the rotating member 80 come into contact with each other at multiple points and receive the resilient force of the resilient member 42, so that the resilient force of the resilient member 42 is dispersed, thereby reducing the stress acting between the engaging members 91, 92 and the rotating member 80. This makes it possible to prevent damage to the retractable mechanism 40.

[0064] In the writing instrument 10 of this embodiment, the angle θ2 between the rear wall 82b of the second slit 82 and the axial direction da is smaller than the angle θ1 between the front wall 81a of the first slit 81 and the axial direction da.

[0065] With this writing instrument 10, when the first slit 81 and the second slit 82 rotate integrally in the circumferential direction dc, the movement distance L2 of the second engagement member 92 in the axial direction da can be made greater than the movement distance L1 of the first engagement member 91 in the axial direction da, with a simple configuration. Furthermore, by adjusting the angles θ1 and θ2, a desired stroke ratio can be achieved.

[0066] The writing instrument 10 of this embodiment has a rotating member 80 disposed inside the barrel 20, and the first slit 81 and the second slit 82 are provided in the rotating member 80.

[0067] According to such writing instrument 10, since both first slit 81 and second slit 82 are provided in one rotating member 80, it is possible to form a compact rotating member 80. This reduces the number of parts in retractable mechanism 40, and makes it possible to make retractable mechanism 40 smaller.

[0068] In the writing instrument 10 of this embodiment, at least a portion of the second slit 82 overlaps with at least a portion of the first slit 81 when viewed in the axial direction da.

[0069] In the writing instrument 10 of this embodiment, at least a portion of the second slit 82 overlaps with at least a portion of the first slit 81 when viewed in the circumferential direction dc.

[0070] By arranging the first slit 81 and the second slit 82 in this manner, it is possible to reduce the space required for arranging the first slit 81 and the second slit 82. Therefore, it is possible to reduce the size of the retractable mechanism 40.

[0071] The writing instrument 10 of this embodiment is provided with an inner tube 70 fixed to the barrel 20 and having a first elongated hole 71 extending in the axial direction da and a second elongated hole 72 extending in the axial direction da, and a first engaging member 91 engages with the first elongated hole 71, and a second engaging member 92 engages with the second elongated hole 72.

[0072] According to this writing instrument 10, the engaging members 91, 92 can be moved in the axial direction da while the rotation of the engaging members 91, 92 in the circumferential direction dc is restricted by the long holes 71, 72. The combination of the long holes 71, 72 and the slits 81, 82 allows the engaging members 91, 92 to move smoothly back and forth.

[0073] In the writing instrument 10 of this embodiment, the portion (contact surface) 91a of the first engagement member 91 that faces the side wall surface 71a of the first elongated hole 71 is flat.

[0074] In the writing instrument 10 of this embodiment, the portion (contact surface) 92a of the second engagement member 92 that faces the side wall surface 72a of the second elongated hole 72 is flat.

[0075] In this writing instrument 10, the flat contact surfaces 91a, 92a increase the contact area between the contact surfaces 91a, 92a and the side wall surfaces 71a, 72a, thereby reducing the pressure acting on the contact surfaces 91a, 92a. This reduces wear on the contact surfaces 91a, 92a when the contact surfaces 91a, 92a slide against the side wall surfaces 71a, 72a.

Claims

1. A writing instrument comprising: a barrel having a front end opening; a writing element disposed in the barrel; and a retraction mechanism for causing the tip of the writing element to protrude and retract from the front end opening, The retractable mechanism is a first slit extending spirally around the central axis of the barrel and rotatable in a circumferential direction; a second slit disposed in front of the first slit, extending spirally around the central axis, and rotatable in the circumferential direction integrally with the first slit; a first engagement member that engages with the first slit; a second engagement member that engages with the second slit, When the first engagement member pushes the first slit forward, the first slit and the second slit rotate together in the circumferential direction, A writing implement, wherein when the first slit and the second slit rotate integrally in the circumferential direction, the axial movement distance of the second engagement member is greater than the axial movement distance of the first engagement member.

2. The writing implement according to claim 1 , wherein an angle between a rear wall of the second slit and the axial direction is smaller than an angle between a front wall of the first slit and the axial direction.

3. a rotating member disposed within the barrel, The writing implement according to claim 1 , wherein the first slit and the second slit are provided in the rotary member.

4. The writing instrument according to claim 1 , wherein at least a portion of the second slit overlaps with at least a portion of the first slit when viewed in the axial direction.

5. The writing implement according to claim 1 , wherein at least a portion of the second slit overlaps with at least a portion of the first slit when viewed in the circumferential direction.

6. an inner cylinder fixed to the barrel cylinder and having a first elongated hole extending in the axial direction and a second elongated hole extending in the axial direction; the first engagement member engages with the first elongated hole, The writing implement according to any one of claims 1 to 5, wherein the second engagement member engages with the second elongated hole.

7. The writing implement according to claim 6 , wherein a portion of the first engagement member facing the side wall surface of the first elongated hole is a flat surface.

8. The writing implement according to claim 6 , wherein a portion of the second engagement member facing the side wall surface of the second elongated hole is flat.

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