Notebook

Abstract

To provide a writing instrument of which a knock member can be pressed forward with a force smaller than an elastic force of an elastic member.SOLUTION: A writing instrument 10 includes a shaft tube 20 having a front-end opening 20a, a writing member 15 disposed inside the shaft tube 20, and a thrust mechanism 30 that thrusts out a tip of the writing member 15 from the front-end opening 20a. The thrust mechanism 30 has a knock member 31 that a user can press forward and an elastic member 38 that urges the writing member 15 backward, and a force required to press the knock member 31 forward is smaller than an elastic force of the elastic member 38.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, there has been known a writing instrument that includes a barrel, a writing element disposed within the barrel, and a feeding mechanism that feeds the tip of the writing element from the front end of the barrel in response to the operation of a knocking element (see, for example, Patent Document 1). The feeding mechanism is disposed between the barrel and the writing element and has a resilient element that biases the writing element rearward.

[0003] As an example, in such a writing instrument, when a user presses the knock member forward, the writing member moves forward against the resilient force of the resilient member, and the tip of the writing member protrudes forward from the front end of the barrel. Even when the forward pressure on the knock member is released, the writing member maintains a state in which the tip of the writing member protrudes forward from the front end of the barrel. When the user presses the knock member forward in this state, the writing member moves forward a small distance. When the forward pressure on the knock member is released, the resilient force of the resilient member causes the writing member to move backward, and the tip of the writing member retracts from the front end of the barrel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-108668 Summary of the Invention [Problem to be solved by the invention]

[0005] In a conventional writing instrument equipped with a feeding mechanism, in order to reduce the force required to press the knock member forward, it is necessary to reduce the resilient force of the resilient member. Furthermore, if the resilient force of the resilient member is increased, the force required to press the knock member forward also increases. Therefore, it was not possible to determine the force required to press the knock member forward and the resilient force of the resilient member independently. In particular, it was not possible to make the force required to press the knock member forward smaller than the resilient force of the resilient member.

[0006] The present invention has been made in consideration of the above points, and has an object to provide a writing implement that can press a knock member forward with a force smaller than the resilience of the resilient member. [Means for solving the problem]

[0007] The writing instrument according to the present invention comprises: A writing instrument comprising: a barrel having a front end opening; a writing element disposed in the barrel; and a mechanism for feeding the tip of the writing element out from the front end opening, The dispensing mechanism has a knock member that can be pressed forward by a user and a resilient member that urges the writing member backward, The force required to press the knock member forward is smaller than the resilience of the resilient member.

[0008] In the writing instrument according to the present invention, The dispensing mechanism includes: The writing device may further include a pressing force increasing mechanism that increases the pressing force applied to the knock member and transmits the increased pressing force to the writing member when the knock member is pressed forward.

[0009] In the writing instrument according to the present invention, The pressing force increasing mechanism includes: a pressing member whose angle with respect to the central axis of the barrel is changed in accordance with forward movement of the knock member; a slide member that moves forward by a pressing force from the pressing member and moves from one side to the other side in a first direction perpendicular to the central axis of the barrel; The slide member may further include a pressed member that is movable forward by the pressing force from the slide member.

[0010] In the writing instrument according to the present invention, the pressing member has a longitudinal axis in a cross section parallel to the central axis and the first direction, As the knock member moves forward, the angle between the central axis and the longitudinal axis may increase.

[0011] In the writing instrument according to the present invention, the knock member has a pressing surface that presses the pressing member, The pressing surface may extend from the front to the rear as it moves from the one side to the other side in the first direction.

[0012] In the writing instrument according to the present invention, An inclined surface is formed on the inner surface of the barrel, the inclined surface extending from rear to front as it moves from the one side to the other side in the first direction, When the knock member moves forward, the slide member may move along the inclined surface.

[0013] In the writing instrument according to the present invention, The slide member may have a guide portion that guides the pressing member. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a writing implement in which the knock member can be pressed forward with a force smaller than the resilience of the resilient member. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram for explaining a first 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 vertical cross-sectional view showing the pressing force increasing mechanism of the writing implement of FIG. [Figure 3] FIG. 3 is a vertical cross-sectional view showing the writing implement of FIG. 1 in a protruding state. [Figure 4] FIG. 4 is an enlarged vertical cross-sectional view showing the pressing force increasing mechanism of the writing implement of FIG. [Figure 5] FIG. 5 is a perspective view showing the rear barrel of the barrel of the writing instrument cut along the central axis. [Figure 6] FIG. 6 is an enlarged perspective view of the pressing force increasing mechanism in the immersed state. [Figure 7] FIG. 7 is an exploded perspective view of the writing implement. [Figure 8] FIG. 8 is an exploded perspective view of a portion of the pressing force increasing mechanism. [Figure 9] FIG. 9 is a diagram for explaining the operation of the pressing force increasing mechanism. [Figure 10] FIG. 10 is a diagram for explaining the second embodiment of the present invention, and is a vertical cross-sectional view showing another example of a writing implement in a non-knocking state. [Figure 11] 11 is an enlarged vertical cross-sectional view of the pressing force increasing mechanism of the writing implement of FIG. [Figure 12] 12 is an enlarged longitudinal cross-sectional view of the front portion of the writing implement of FIG. [Figure 13] FIG. 13 is a vertical cross-sectional view showing the writing implement of FIG. 10 in a knocked state. [Figure 14] 14 is an enlarged vertical cross-sectional view showing the pressing force increasing mechanism of the writing implement of FIG. [Figure 15] 15 is an enlarged longitudinal cross-sectional view of the front portion of the writing implement of FIG. 13. FIG. [Figure 16] FIG. 16 is a perspective view showing the inner shaft of the barrel of the writing implement cut along the central axis. [Figure 17] FIG. 17 is an enlarged perspective view of the pressing force increasing mechanism in the non-knocking state. [Figure 18] FIG. 18 is an exploded perspective view of the writing implement. [Figure 19] FIG. 19 is an exploded perspective view of a portion of the pressing force increasing mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios of the actual objects have been appropriately changed and exaggerated for the sake of convenience in 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 (the up-down direction in a longitudinal cross-sectional view) 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. Along the axial direction da, the side that comes close to a writing surface such as a paper surface when writing (the pen tip side) is referred to as the front, and the side that moves away from the writing surface (the side opposite the pen tip) is referred to as the rear. Also, along the radial direction, the side that approaches the central axis A is referred to as the inside or inner side, and the side that moves away from the central axis A is referred to as the outside or outer side.

[0019] First embodiment FIG. 1 is a diagram for explaining one embodiment of the present invention, and is a longitudinal cross-sectional view showing an example of a writing instrument 10 in a immersed state, FIG. 2 is a longitudinal cross-sectional view showing an enlarged pressing force increasing mechanism 40 of the writing instrument 10, FIG. 3 is a longitudinal cross-sectional view showing the writing instrument 10 in a protruding state, and FIG. 4 is a longitudinal cross-sectional view showing an enlarged pressing force increasing mechanism 40 of the writing instrument 10 of FIG. 3.

[0020] The writing instrument 10 of this embodiment includes a writing member 15, a barrel 20, and a dispenser mechanism 30. The writing instrument 10 extends along a central axis A. The writing member 15 is a member that writes on a writing surface such as paper. The writing member 15 is housed within the barrel 20. Examples of the writing member 15 include members used in ballpoint pens, fountain pens, markers, rod-shaped lead dispensers (such as mechanical pencils, knock-type eraser dispensers, and knock-type crayon dispensers), stylus pens, and the like. In this embodiment, an example will be described in which the writing instrument 10 is a ballpoint pen. In this case, the writing member 15 is a refill for a ballpoint pen. The writing member 15 of this embodiment includes ink, a dispenser tube that accommodates the ink, a writing portion 17 provided at the front end, and a first receiving portion 18 that receives the resilient force of a resilient member 38 (described below). The first receiving portion 18 is a surface facing forward in a step formed on the outer surface of the writing member 15.

[0021] As the ink, any ink that can be used for a ballpoint pen can be used without any particular limitation. As an example, a thermochromic ink can be used. The thermochromic ink may be a reversible thermochromic ink. As the reversible thermochromic ink, various reversible thermochromic inks may be used alone or in combination, such as a thermal decolorization type that changes from a colored state to a decolorized state when heated and changes from the decolorized state to a colored state when cooled, a thermal color development type that changes from a decolorized state to a colored state when heated and changes from the colored state to the decolorized state when cooled, or a color memory retention type that exhibits a specific color in a specific temperature range and changes color depending on the temperature.

[0022] Barrel tube 20 includes front barrel 21, center barrel 22 arranged behind front barrel 21, and rear barrel 23 arranged behind center barrel 22. The central axis of barrel 20 coincides with central axis A of writing instrument 10. Barrel tube 20 has, at its front end, front end opening 20a through which the tip of writing member 15 (writing part 17) can appear and disappear. Front barrel 21 is a member having a generally cylindrical shape. In this embodiment, front end opening 20a is formed at the front end of front barrel 21. A second receiving portion 20b that receives the elastic force of elastic member 38, which will be described later, is formed on the inner surface of front barrel 21. Second receiving portion 20b is the rear-facing surface of a step formed on the inner surface of front barrel 21.

[0023] Center shaft 22 is a generally cylindrical member disposed behind front shaft 21. The front end of center shaft 22 is attached to the rear end of front shaft 21, thereby connecting center shaft 22 to front shaft 21. As an example, a male thread formed on the outer periphery of the rear end of front shaft 21 is threadedly engaged with a female thread formed on the inner periphery of the front end of center shaft 22, thereby connecting center shaft 22 to front shaft 21. In this embodiment, writing element 15 can be replaced by removing center shaft 22 from front shaft 21. The inner circumferential surface of center shaft 22 is formed with a plurality of sawtooth-shaped cam teeth that protrude forward, and grooves that are formed between the cam teeth and extend in the axial direction da.

[0024] The rear axle 23 is a member having a generally cylindrical shape and is disposed rearward of the center axle 22. The front end of the rear axle 23 is attached to the rear end of the center axle 22, thereby connecting the rear axle 23 to the center axle 22. As an example, the rear end of the center axle 22 is press-fitted into the front end of the rear axle 23, thereby connecting the rear axle 23 to the center axle 22. However, this is not limitative, and the rear axle 23 may also be connected to the center axle 22 by threading a thread formed on the front end of the rear axle 23 into a thread formed on the rear end of the center axle 22.

[0025] FIG. 5 is a perspective view showing the rear axle 23 cut along the central axis A. In this embodiment, an inclined surface 20c, a first guide surface 20d, and a second guide surface 20e are formed on the inner surface of the rear axle 23. The inclined surface 20c functions to guide a rear surface 52 of a slide member 50 (described later). The inclined surface 20c is a forward-facing surface of a step formed on the inner surface of the rear axle 23, and extends from rear to front as it moves from one side to the other in a first direction d1 perpendicular to the central axis A. In the example shown in FIG. 5, the inclined surface 20c is a flat surface. The first guide surface 20d is a flat surface extending parallel to the axial direction da and the first direction and is a surface that guides a side surface 53 of the slide member 50. The second guide surface 20e is a flat surface extending parallel to the axial direction da and the first direction and is a surface that guides a side surface 31d of a knock member 31 (described later).

[0026] A crown 29 is attached to the rear end of the rear axle 23. As an example, the rear end of the rear axle 23 is press-fitted into the front end of the crown 29, thereby connecting the crown 29 to the rear axle 23. However, this is not limitative, and the crown 29 may be connected to the rear axle 23 by threading a thread formed on the front end of the crown 29 into a thread formed on the rear end of the rear axle 23. The crown 29 has a through-hole through which an operating portion 31a of a knock member 31 (described below) is inserted. The crown 29 has the function of preventing the knock member 31 from slipping out rearward from the barrel tube 20.

[0027] The dispensing mechanism 30 is a mechanism for advancing the tip of the writing member 15 (writing part 17) from the front end opening 20a of the barrel 20 (front barrel 21). In this embodiment, the dispensing mechanism 30 has the function of alternately switching the writing instrument 10 between a protruding state in which the tip of the writing member 15 protrudes from the front end opening 20a of the front barrel 21, and a retracted state in which the tip of the writing member 15 is retracted from the front end opening 20a. Therefore, the dispensing mechanism 30 of this embodiment can also be called a protruding / retracting mechanism. The dispensing mechanism 30 of this embodiment includes a knock member 31, an engaging member 34, a rotating cam member 36, a resilient member 38, and a pressing force increasing mechanism 40.

[0028] The knock member 31 is a member intended to be operated by the user. The knock member 31 is configured to be movable back and forth and has an operating portion 31a and a front portion 31b located in front of the operating portion 31a. The operating portion 31a is the portion that is pressed by the user's finger or the like. The operating portion 31a protrudes rearward through a through-hole provided in the crown 29. In the retracted state and the protruding state, the rear end of the operating portion 31a protrudes rearward from the rear end of the barrel 20. In this embodiment, in the retracted state and the protruding state, the rear end of the operating portion 31a protrudes rearward from the crown 29. The front portion 31b has a dimension in the first direction d1 that is larger than the radial dimension of the operating portion 31a. The inner diameter of the through-hole in the crown 29 is large enough to allow the operating portion 31a to pass through but not the front portion 31b. Therefore, the knock member 31 does not slip rearward through the through-hole in the crown 29.

[0029] The front portion 31b has a pressing surface 31c provided at its front end and a pair of side surfaces 31d facing in a second direction d2 (see FIG. 8 ) perpendicular to both the axial direction da and the first direction d1. The pressing surface 31c is a surface that presses the pressing member 60. In this embodiment, the pressing surface 31c extends from the front to the rear as it moves from one side to the other in the first direction d1. The pressing surface 31c may be flat. The pressing surface 31c may also have a shape other than a flat surface, such as a curved surface. The pressing surface 31c does not have to be inclined with respect to the central axis A. That is, the pressing surface 31c may extend perpendicular to the central axis A. Each side surface 31d extends parallel to the axial direction da and the first direction d1, and the pair of side surfaces 31d are parallel to each other. In the illustrated example, all of the side surfaces 31d are flat. The pair of side surfaces 31d are guided by the second guide surfaces 20e of the barrel 20 (rear barrel 23), respectively, thereby restricting the rotation of the knock member 31 in the circumferential direction.

[0030] The engaging member 34 is a member having a generally cylindrical shape as a whole. Cam teeth 34a that protrude forward are formed at the front end of the engaging member 34. In addition, a protrusion 34b that engages with a groove formed in the inner peripheral surface of the barrel 20 (center shaft 22) is formed on the outer peripheral surface of the engaging member 34. With the protrusion 34b engaged with the groove of the barrel 20, the engaging member 34 is arranged so as to be movable in the axial direction da but not rotatable in the circumferential direction.

[0031] The rotating cam member 36 has on its outer surface a plurality of ridges 36a that extend in the axial direction da and engage with grooves in the barrel 20. Cam surfaces 36b that are inclined relative to the axial direction da and the circumferential direction are formed at the rear ends of the ridges 36a. The cam surfaces 36b engage with the cam teeth 34a of the engaging member 34.

[0032] The resilient member 38 is, for example, a coil spring. The resilient member 38 is disposed in a compressed state between the first receiving portion 18 of the writing member 15 and the second receiving portion 20b of the barrel 20 (front barrel 21). Therefore, the resilient member 38 constantly biases the writing member 15 backward relative to the barrel 20.

[0033] In the present embodiment, when the user presses the knock member 31 forward, the writing member 15 moves forward via the pressing force increasing mechanism 40, the engaging member 34, and the rotating cam member 36, causing the tip of the writing member 15 to protrude forward from the front-end opening 20a. Even when the forward pressure on the knock member 31 is released, the writing member 15 maintains a state in which the tip of the writing member 15 protrudes forward from the front-end opening 20a. When the user presses the knock member 31 forward, the writing member 15 moves a small distance forward. When the forward pressure on the knock member 31 is released, the resilient force of the resilient member 38 causes the writing member 15 to move backward, causing the tip of the writing member 15 to retract from the front-end opening 20a. The specific structures and operations of the groove portion of the barrel 20, the engagement member 34, and the rotating cam member 36 that realize such extending and retracting operations are well known, so detailed explanations will be omitted. As an example, the mechanism disclosed in Figure 5 of JP 2018-108668 A (Patent Document 1) can be used.

[0034] In this embodiment, the writing instrument 10 is configured so that the force required to press the knock member 31 forward is smaller than the resilient force of the resilient member 38. An example of a pressing force increasing mechanism 40 that achieves this function will be described mainly with reference to Figures 2 and 4 to 9. Figure 6 is an enlarged perspective view of the pressing force increasing mechanism 40 in the immersed state, Figure 7 is an exploded perspective view of the entire writing instrument 10, Figure 8 is an exploded perspective view of a portion of the pressing force increasing mechanism 40, and Figure 9 is a diagram for explaining the operation of the pressing force increasing mechanism 40.

[0035] Pressing force increasing mechanism 40 of the present embodiment includes inclined surface 20c, first guide surface 20d, second guide surface 20e, knock member 31, slide member 50, and pressing member 60, which are formed on the inner surface of rear barrel 23. As described above, inclined surface 20c is a rearward-facing surface of a step formed on the inner surface of rear barrel 23, and extends from rear to front as it moves from one side to the other in first direction d1 perpendicular to central axis A (see FIG. 5).

[0036] The pressing member 60 transmits the pressing force received from the knock member 31 to the slide member 50. The pressing member 60 has a front end 62, a rear end 64, and side surfaces 66. The pressing member 60 has a generally rectangular columnar shape overall. In this case, the pressing member 60 has four side surfaces 66 connecting the front end 62 and the rear end 64. The front end 62 and the rear end 64 are given a rounded shape. In particular, the front end 62 and the rear end 64 both have an arc-shaped outline in a cross section perpendicular to the second direction d2. More specifically, the front end 62 and the rear end 64 both have a semicircular outline in a cross section perpendicular to the second direction d2. The rounded shapes of the front end 62 and the rear end 64 allow the pressing member 60 to smoothly change its angle and prevent scratches or sticking from occurring to the knock member 31 and the pressed member 70. The sticking phenomenon refers to a state in which parts stick together, causing an impediment to operation. The rear end portion 64 comes into contact with the pressing surface 31c of the knock member 31.

[0037] One of the four side surfaces 66 serves as an abutment surface 68 that abuts against the abutment portion 58 of the slide member 50. In particular, of the four side surfaces 66, the side surface 66 facing forward and toward the other side in the first direction d1 serves as the abutment surface 68. All four side surfaces 66 may be flat. Furthermore, chamfered portions may be formed between the side surface 66 and the front end portion 62, between the side surface 66 and the rear end portion 64, and between two adjacent side surfaces 66.

[0038] The pressing member 60 is configured so that its angle with respect to the central axis A changes as the knock member 31 moves. As the angle of the pressing member 60 changes, the pressing member 60 presses the abutment portion 58 of the slide member 50 with the abutment surface 68. In this embodiment, the pressing member 60 is configured so that the angle of the pressing member 60 changes with respect to the longitudinal axis A in a cross section parallel to the central axis A and the first direction d1. L The longitudinal axis A L is an axis extending in a direction in which the dimension of the pressing member 60 is maximum when measured in any direction in a cross section parallel to the central axis A and the first direction d1. L The longitudinal axis A coincides with the direction of the straight line connecting the front end 62 and the rear end 64. As shown in FIG. L extends in a direction inclined with respect to the axial direction da and the first direction d1.

[0039] In this embodiment, as shown in FIGS. 2 and 4, the central axis A and the longitudinal axis A L In particular, when the knock member 31 moves forward, the entire pressing member 60 moves forward due to the knock member 31, and the angle between the central axis A and the longitudinal axis A L As can be seen from Figures 2 and 4, the angle between the central axis A and the longitudinal axis A in the protruding state changes. L The angle θ2 between the central axis A and the longitudinal axis A in the immersed state LIn other words, when the knock member 31 moves forward, the angle θ1 between the central axis A and the longitudinal axis A L The angle between the central axis A and the longitudinal axis A becomes larger. L The angle between the central axis A and the longitudinal axis A in a cross section parallel to the central axis A and the first direction d1 is L It refers to the smaller of the two angles formed by and.

[0040] The slide member 50 is a member that transmits the pressing force received from the pressing member 60 to the pressed member 70. The slide member 50 is located between the knock member 31 and the pressed member 70. In particular, the slide member 50 is located between the inclined surface 20c of the barrel 20 (rear barrel 23) and the pressed member 70. The slide member 50 is configured to be able to move forward and from one side to the other in a first direction d1 perpendicular to the central axis A when it receives a pressing force from the pressing member 60.

[0041] The slide member 50 has a front surface 51 facing forward, a rear surface 52 facing rearward, and a pair of side surfaces 53 facing in the second direction d2. The front surface 51 abuts against a pressure-receiving surface 72 (described later) of the pressed member 70 and extends in a direction perpendicular to the central axis A. The rear surface 52 extends from rear to front as it moves from one side to the other in the first direction d1 (see FIG. 8). In the illustrated example, the rear surface 52 is flat. When it receives a pressing force from the pressing member 60, the rear surface 52 slides along the inclined surface 20c of the barrel 20 (rear axle 23), causing the pressing member 60 to move from one side to the other in the first direction d1. As a result, the slide member 50 moves forward and from one side to the other in the first direction d1. Each side surface 53 extends parallel to the axial direction da and the first direction d1, and the pair of side surfaces 53 are parallel to each other. In the illustrated example, both side surfaces 53 are flat surfaces. The pair of side surfaces 53 are guided by the first guide surfaces 20d of the barrel 20 (rear barrel 23). This restricts the rotation of the slide member 50 in the circumferential direction.

[0042] A recess 54 is formed in the slide member 50. The recess 54 extends in the axial direction da and the first direction d1 and is open to the front surface 51, the rear surface 52, and one side in the first direction d1. The recess 54 includes a pair of side surfaces 56 facing each other in the second direction d2. Each side surface 56 extends parallel to the axial direction da and the first direction d1, and the pair of side surfaces 56 are parallel to each other. In the illustrated example, all of the side surfaces 56 are flat. The pair of side surfaces 56 constitute a guide portion that guides the pressing member 60. Therefore, in this specification, the pair of side surfaces 56 may also be referred to as a guide portion 56. The pressing member 60 is located between the pair of side surfaces 56 of the recess 54 of the slide member 50, and movement of the pressing member 60 in the second direction d2 is restricted by the guide portion 56 constituted by the pair of side surfaces 56.

[0043] The slide member 50 has an abutment portion 58 against which the pressing member 60 abuts. In particular, the abutment surface 68 of the pressing member 60 abuts against the abutment portion 58 of the slide member 50. In the example shown in FIG. 8 , the abutment portion 58 is formed at the connection portion between the rear surface 52 and the recess 54 and extends in the second direction d2. The abutment surface 68 of the pressing member 60 presses against the abutment portion 58, thereby transmitting a pressing force from the pressing member 60 to the slide member 50. In the example shown, the abutment portion 58 may have a chamfered portion. The chamfered portion may have a rounded shape. For example, the chamfered portion may have an arc-shaped cross section perpendicular to the second direction d2. If the abutment portion 58 has a chamfered portion, scratches or digging into the abutment surface 68 of the pressing member 60 can be prevented.

[0044] The pressed member 70 is a member that receives a pressing force from the slide member 50. The pressed member 70 transmits the pressing force received from the slide member 50 to the engaging member 34. The pressed member 70 is configured to be movable back and forth, and has a pressure-receiving surface 72 and a support surface 74 provided at its rear end. The pressure-receiving surface 72 is a surface that receives a pressing force from the slide member 50. In this embodiment, the pressure-receiving surface 72 extends perpendicular to the central axis A. The pressure-receiving surface 72 may be a flat surface. The support surface 74 is a surface that supports the pressing member 60. In particular, the support surface 74 supports the front end 62 of the pressing member 60. In this embodiment, the support surface 74 extends from rear to front as it moves from one side to the other in the first direction d1. The support surface 74 may be a flat surface. The pressed member 70 receives a pressing force from the slide member 50 mainly via the pressure-receiving surface 72, but may also receive a pressing force from the pressing member 60 via the support surface 74. The rear end of the engaging member 34 is inserted into the front portion of the pressed member 70. The pressed member 70 and the engaging member 34 may or may not be fixed to each other.

[0045] The writing instrument 10 of this embodiment has two components, a slide member 50 and a pressing member 60, that transmit the pressing force from the knock member 31 to the pressed member 70. In this case, the force acting on each component can be dispersed compared to when the pressing force from the knock member is transmitted to the pressed member using a single component. This effectively prevents deformation or damage to the component that transmits the pressing force from the knock member 31 to the pressed member 70. This allows the writing member 15 to stably extend and retract.

[0046] Next, referring to Figure 9, we will explain how the pressing force increasing mechanism 40 of this embodiment increases the pressing force applied to the knock member 31 and transmits it to the writing member 15. Figure 9 schematically shows the knock member 31, the slide member 50, and the pressing member 60. The slide member 50 is shown in cross section parallel to the axial direction da and the first direction d1.

[0047] The pressing member 60 of this embodiment functions as a so-called "lever." The front end 62 of the pressing member 60 is a fulcrum 81, the rear end 64 is a force point 83, and the part of the abutment surface 68 that abuts against the abutment portion 58 of the slide member 50 is a point of action 85. Here, the longitudinal axis A of the pressing member 60 L The distance between the fulcrum 81 and the force point 83 measured along the arrow is defined as X1, and the distance between the fulcrum 81 and the action point 85 is defined as X2. Furthermore, the force with which the user presses the knock member 31 forward is defined as F1, and the force acting from the pressing member 60 to the slide member 50 is defined as F2. In this case, based on the principle of leverage, the following equation holds between the distance X1, the distance X2, the pressing force F1, and the pressing force F2. F1 × X1 = F2 × X2 (Formula 1) Therefore, the pressure force F2 can be expressed as follows: F2 = F1 × (X1 / X2) (Formula 2) 9, the distance X2 is smaller than the distance X1. That is, X1 / X2>1. Therefore, the pressing force F1 and the pressing force F2 have the following relationship. F2 > F1 (Formula 3)

[0048] This pressing force F2 is transmitted from the slide member 50 to the writing member 15 via the pressed member 70, the engaging member 34, and the rotating cam member 36. In this embodiment, the distance X2 between the fulcrum 81 and the point of application 85 is smaller than the distance X1 between the fulcrum 81 and the point of application 83, and therefore the pressing force F2 that presses the writing member 15 forward is greater than the pressing force F1 applied to the knock member 31 in the pressing force increasing mechanism 40. For example, if the distance X1 is twice the distance X2, then X1 / X2=2, and therefore, according to the above formula 2, the pressing force F2 is twice the pressing force F1.

[0049] When the knock member 31 moves forward, the slide member 50 also moves forward and from one side to the other in the first direction d1. At this time, the distance X1 remains almost constant, but the distance X2 increases. That is, the value of X1 / X2 decreases. However, as can be seen from FIGS. 2 and 4, in this embodiment, the distance X1 is greater than the distance X2 throughout the entire process from the retracted state to the extended state. That is, the value of X1 / X2 is always greater than 1. Therefore, as the knock member 31 moves forward, the increase factor (F2 / F1) of the pressing force in the pressing force increasing mechanism 40 decreases, but remains greater than 1. That is, the pressing force F2 pressing the writing member 15 forward is always greater than the pressing force F1 applied to the knock member 31.

[0050] Next, the extending and retracting operation of the writing instrument 10 will be described mainly with reference to Figures 1 to 4. Figures 1 and 2 show the writing instrument 10 in a retracted state, and Figures 3 and 4 show the writing instrument 10 in a protruding state.

[0051] In the immersed state, the writing member 15 is urged rearward by the resilient force of the resilient member 38. As a result, the rotating cam member 36 and the engaging member 34 are also urged rearward, and the protrusion 34b of the engaging member 34 is positioned at the rear end of the groove formed on the inner peripheral surface of the barrel 20 (center shaft 22). With the engaging member 34 positioned at the rear end of its range of movement in the axial direction da, the pressed member 70, the sliding member 50, the pressing member 60, and the knocking member 31 are each positioned at the rear part of their range of movement in the axial direction da. In the immersed state, the sliding member 50 is positioned on one side in the first direction d1. At this time, the longitudinal axis A of the pressing member 60 is L and the central axis A is θ1. The length of the pressing member 60 along the axial direction da is L1. Furthermore, the length along the axial direction da between the contact portion between the pressing surface 31c of the knock member 31 and the rear end portion 64 of the pressing member 60 and the rear end of the knock member 31 is L2.

[0052] When the user presses the knock member 31 forward, the knock member 31 moves forward against the resilient force of the resilient member 38. The pressing member 60 receives the forward pressing force from the knock member 31 and moves forward. Also, the rear end 64 of the pressing member 60 receives the pressing force from the knock member 31 and moves toward the other side in the first direction d1. At this time, the position of the front end 62 of the pressing member 60 in the first direction d1 hardly changes. Therefore, the angle of the pressing member 60 with respect to the central axis A changes. In particular, the relationship between the central axis A and the longitudinal axis A L The angle between the central axis A and the longitudinal axis A in the immersed state L The angle between the two points is larger than the angle θ1.

[0053] As the angle of the pressing member 60 relative to the central axis A is changed, the contact surface 68 of the pressing member 60 contacts and presses the contact portion 58 of the sliding member 50. The sliding member 50 receives the pressing force from the pressing member 60 and moves forward from one side to the other in the first direction d1. In particular, the sliding member 50 moves while the rear surface 52 slides along the inclined surface 20c formed on the inner surface of the barrel 20 (rear barrel 23). As the sliding member 50 moves forward, the pressed member 70 receives the pressing force from the sliding member 50 and moves forward. As a result, the pressed member 70, the engaging member 34, the rotating cam member 36, and the writing member 15 move forward against the resilient force of the resilient member 38. When the knock member 31 moves further forward, the writing instrument 10 assumes the protruding state shown in FIGS. 3 and 4.

[0054] As described with reference to Figure 9, in this embodiment, the pressing force that presses writing member 15 forward is greater than the pressing force applied to knock member 31. That is, in writing instrument 10 of this embodiment, the user can press writing member 15 forward against the resilient force of resilient member 38 with a force greater than the pressing force applied to knock member 31. In other words, the force required to press knock member 31 forward is smaller than the resilient force of resilient member 38.

[0055] People with weak fingers, such as children and the elderly, may have difficulty extending the tip of the writing member from the front-end opening of the barrel against the resilient force of the resilient member. In conventional writing instruments, the resilience of the resilient member must be reduced to allow even people with weak fingers to easily extend the writing member. However, reducing the resilience of the resilient member causes the writing member to rattle inside the barrel, making stable writing difficult. In contrast, in this embodiment, the force required to press the knock member 31 forward is less than the resilience of the resilient member 38. This allows for a writing instrument 10 that allows even people with weak fingers to easily extend the writing member 15 without reducing the resilience of the resilient member 38.

[0056] In addition, in writing instruments, it may be desirable to reduce the clearance between the outer peripheral surface of the front portion of the writing member and the inner peripheral surface of the front shaft and configure the front portion of the writing member to be press-fit into the front shaft, thereby suppressing wobble of the writing member and enabling stable writing. However, in conventional writing instruments, when the front portion of the writing member is configured to be press-fit into the front shaft, the resilient force of the resilient member must be increased to urge the writing member rearward against the frictional force between the writing member and the front shaft during the extension / retraction operation. However, increasing the resilient force of the resilient member increases the force required to press the knock member forward, making the extension / retraction operation difficult. In contrast, in this embodiment, the user can press the writing member 15 forward with a force greater than the pressing force applied to the knock member 31. Therefore, even if the resilient force of the resilient member is increased, there is no need to change the force required to press the knock member 31 forward against this resilient force. Therefore, while maintaining easy extension and retraction operation, rattle of the writing member 15 can be suppressed, allowing stable writing.

[0057] The central axis A and the longitudinal axis A of the pressing member 60 L The angle between the central axis A and the longitudinal axis A in the immersed state LBy making the angle θ1 between the sliding member 50 and the pressing member 60 larger than the angle θ1, the length of the pressing member 60 along the axial direction da becomes smaller. Therefore, even if the pressing surface 31c of the knock member 31 is not inclined with respect to the central axis A, the forward movement stroke of the pressed member 70, which moves forward in response to the pressing force from the sliding member 50, is smaller than the forward movement stroke of the knock member 31. The writing member 15 moves forward integrally with the pressed member 70 via the engaging member 34 and the rotating cam member 36. Therefore, the forward movement distance of the writing member 15 along the axial direction da is shorter than the forward movement distance of the knock member 31 along the axial direction da.

[0058] In this embodiment, the pressing surface 31c of the knock member 31 is inclined with respect to the central axis A. Specifically, the pressing surface 31c extends from front to rear as it moves from one side to the other in the first direction d1. As the angle of the pressing member 60 relative to the central axis A changes, the contact portion between the pressing surface 31c of the knock member 31 and the rear end 64 of the pressing member 60 moves from one side to the other in the first direction d1. As a result, the length along the axial direction da between the contact portion and the rear end of the knock member 31 becomes shorter than the length L2 along the axial direction da between the contact portion and the rear end of the knock member 31 in the retracted state. Therefore, the length along the axial direction da from the front end 62 of the pressing member 60 to the rear end of the knock member 31 becomes even shorter. In this case, the forward movement distance of the writing member 15 along the axial direction da becomes even shorter than the forward movement distance of the knock member 31 along the axial direction da.

[0059] In the protruding state, the slide member 50 is located on the other side in the first direction d1. L and the central axis A is θ2. The length of the pressing member 60 along the axial direction da is L3. Furthermore, the length along the axial direction da between the contact portion between the pressing surface 31c of the knock member 31 and the rear end portion 64 of the pressing member 60 and the rear end of the knock member 31 is L4. In this case, the angle θ2 is greater than the angle θ1. The length L3 is smaller than the length L1. Furthermore, the length L4 is smaller than the length L2.

[0060] The writing instrument 10 of this embodiment comprises a barrel 20 having a front end opening 20a, a writing member 15 arranged within the barrel 20, and a dispensing mechanism 30 that extends the tip of the writing member 15 from the front end opening 20a. The dispensing mechanism 30 has a knock member 31 that can be pressed forward by the user, and a resilient member 38 that urges the writing member 15 backward, and the force required to press the knock member 31 forward is smaller than the resilience of the resilient member 38.

[0061] In conventional writing instruments, if the resilience of the resilient member is reduced so that even people with weak finger strength can easily advance the writing member, the writing member would rattle inside the barrel, making it difficult to write stably. With writing instrument 10 of this embodiment, the force required to press knock member 31 forward is less than the resilience of resilient member 38, so it is possible to realize writing instrument 10 that allows even people with weak finger strength to easily advance writing member 15 without reducing the resilience of resilient member 38.

[0062] Furthermore, in conventional writing instruments, in order to reduce rattle of the writing member and enable stable writing, the front portion of the writing member is configured to be press-fit into the front shaft. However, increasing the resilience of the resilient member increases the force required to press the knock member forward, making the extension / retraction operation difficult. With the writing instrument 10 of this embodiment, the user can press the writing member 15 forward with a force greater than the pressing force applied to the knock member 31. Therefore, even if the resilience of the resilient member is increased, there is no need to change the force required to press the knock member 31 forward against this resilience. Therefore, rattle of the writing member 15 can be reduced, enabling stable writing while maintaining easy extension / retraction operation.

[0063] In the writing instrument 10 of this embodiment, the dispensing mechanism 30 has a pressing force increasing mechanism 40 that increases the pressing force applied to the knock member 31 and transmits it to the writing member 15 when the knock member 31 is pressed forward.

[0064] According to this writing instrument 10, the pressing force increasing mechanism 40 allows the writing member 15 to be pressed forward with a force greater than the pressing force applied by the user to the knock member 31. This allows the force required to press the knock member 31 forward to be smaller than the resilience of the resilient member 38.

[0065] In the writing instrument 10 of this embodiment, the pressing force increasing mechanism 40 includes a pressing member 60 whose angle with respect to the central axis A of the barrel 20 changes as the knock member 31 moves forward, a sliding member 50 that moves forward due to the pressing force from the pressing member 60 and moves from one side to the other in a first direction d1 perpendicular to the central axis A of the barrel 20, and a pressed member 70 that can move forward due to the pressing force from the sliding member 50.

[0066] According to this writing instrument 10, since two components, the slide member 50 and the pressing member 60, are used to transmit the pressing force from the knock member 31 to the pressed member 70, the force acting on each component can be dispersed compared to when a single component is used to transmit the pressing force from the knock member to the pressed member 70. This effectively prevents deformation or damage to the component that transmits the pressing force from the knock member 31 to the pressed member 70. This allows for stable extension and retraction of the writing member 15.

[0067] In the writing instrument 10 of this embodiment, the pressing member 60 has a longitudinal axis A in a cross section parallel to the central axis A and the first direction d1. L When the knock member 31 moves forward, the central axis A and the longitudinal axis A L The angle between increases.

[0068] According to such a writing instrument 10, it is possible to make the pressing force that presses the writing member 15 forward greater than the pressing force applied to the knock member 31 by utilizing the so-called "leverage principle."

[0069] In the writing instrument 10 of this embodiment, the knock member 31 has a pressing surface 31c that presses the pressing member 60, and the pressing surface 31c extends from the front to the rear as it moves from one side to the other side in the first direction d1.

[0070] According to this writing instrument 10, when the knock member 31 moves forward, the rear end 64 of the pressing member 60 moves smoothly toward the other side in the first direction d1 due to the pressing force from the knock member 31. Therefore, the angle of the pressing member 60 with respect to the central axis A can be easily changed.

[0071] In the writing instrument 10 of this embodiment, an inclined surface 20c is formed on the inner surface of the barrel 20, extending from rear to front as it moves from one side to the other in the first direction d1, and when the knock member 31 moves forward, the slide member 50 moves along the inclined surface 20c.

[0072] According to such a writing instrument 10, with a simple configuration, the slide member 50 can be moved from one side to the other side in the first direction d1 as the knock member 31 moves forward.

[0073] In the writing instrument 10 of this embodiment, the slide member 50 has a guide portion 56 that guides the pressing member 60.

[0074] According to such writing instrument 10, the pressing member 60 is guided by the guide portion 56, so that the movement of the pressing member 60 in the second direction d2 is restricted. Therefore, the pressing force can be transmitted from the pressing member 60 to the sliding member 50 in a stable manner.

[0075] Second embodiment The second embodiment will be described with reference to Figures 10 to 19. In the following description and the drawings used in the following description, parts that can be configured similarly to the first embodiment will be denoted by the same reference numerals as those used for the corresponding parts in the first embodiment, and duplicated descriptions will be omitted.

[0076] In this embodiment, the writing instrument 100 is a mechanical pencil. Fig. 10 is a diagram for explaining one embodiment of the present invention, and is a vertical cross-sectional view showing an example of the writing instrument 100 in a non-knock state, Fig. 11 is a vertical cross-sectional view showing an enlarged view of the pressing force increasing mechanism 40 of the writing instrument 100 in a non-knock state, and Fig. 12 is a vertical cross-sectional view showing an enlarged view of the front portion of the writing instrument 100 in a non-knock state. Fig. 13 is a vertical cross-sectional view showing the writing instrument 100 in a knock state, Fig. 14 is a vertical cross-sectional view showing an enlarged view of the pressing force increasing mechanism 40 of the writing instrument 100 in a knock state, and Fig. 15 is a vertical cross-sectional view showing an enlarged view of the front portion of the writing instrument 100 in a knock state.

[0077] In this embodiment, the writing member 15 is a writing lead. Accordingly, in this embodiment, the writing member 15 is also referred to as a writing lead 15. The writing lead 15 is a cylindrical member made of, for example, graphite.

[0078] Barrel tube 20 includes a front shaft 21, a center shaft 22 arranged rearward of front shaft 21, a rear shaft 23 arranged rearward of center shaft 22, a tip member 25 arranged in front of front shaft 21, a connecting member 26 connecting front shaft 21 and tip member 25, and a sleeve 27 attached to the front end of tip member 25. The central axis of barrel 20 coincides with central axis A of writing instrument 100. A front end opening 20a is provided at the front end of barrel 20, through which writing lead 15 can pass. In this embodiment, front end opening 20a is an opening formed at the front end of sleeve 27. Feed-out mechanism 30 has a mechanism that, when operated by the user, feeds out writing lead 15 forward from front end opening 20a.

[0079] Front barrel 21 is a generally cylindrical member that is intended to be grasped with the fingers when a user writes with writing instrument 100. Center barrel 22 is a generally cylindrical member that is disposed behind front barrel 21. Center barrel 22 is connected to front barrel 21 by attaching the front end of center barrel 22 to the rear end of front barrel 21. As an example, center barrel 22 is connected to front barrel 21 by threading a male thread formed on the outer periphery of the rear end of front barrel 21 with a female thread formed on the inner periphery of the front end of center barrel 22. In this embodiment, by removing center barrel 22 from front barrel 21, writing lead 15 can be refilled into lead pipe 32, which will be described later.

[0080] FIG. 16 is a perspective view of the center shaft 22 cut along the central axis A. In this embodiment, an inclined surface 20c, a first guide surface 20d, and a second guide surface 20e are formed on the inner surface of the center shaft 22. The inclined surface 20c functions to guide the rear surface 52 of the slide member 50. The inclined surface 20c is a forward-facing surface of a step formed on the inner surface of the center shaft 22, and extends from rear to front as it moves from one side to the other in a first direction d1 perpendicular to the central axis A. In the example shown in FIG. 16, the inclined surface 20c is a flat surface. The first guide surface 20d is a flat surface extending parallel to the axial direction da and the first direction and serves to guide the side surface 53 of the slide member 50. The second guide surface 20e is a flat surface extending parallel to the axial direction da and the first direction and serves to guide the side surface 31d of the knock member 31.

[0081] The rear axle 23 is a member having a generally cylindrical shape and is disposed rearward of the center axle 22. The front end of the rear axle 23 is attached to the rear end of the center axle 22, thereby connecting the rear axle 23 to the center axle 22. As an example, the rear end of the center axle 22 is press-fitted into the front end of the rear axle 23, thereby connecting the rear axle 23 to the center axle 22. However, this is not limitative, and the rear axle 23 may also be connected to the center axle 22 by threading a thread formed on the front end of the rear axle 23 into a thread formed on the rear end of the center axle 22.

[0082] Tip member 25 is a member that forms the tip portion of writing instrument 100. Tip member 25 has a generally conical shape, and its outer diameter decreases toward the front. Tip member 25 is connected to front barrel 21 by attaching the rear end of tip member 25 to the front end of front barrel 21 via connecting member 26. As an example, a male threaded portion formed on the outer periphery of the front end of connecting member 26 is threadedly engaged with a female threaded portion formed on the inner periphery of the rear end of tip member 25, thereby connecting tip member 25 to connecting member 26. Alternatively, a male threaded portion formed on the outer periphery of the rear end of connecting member 26 is threadedly engaged with a female threaded portion formed on the inner periphery of the front end of front barrel 21, thereby connecting front barrel 21 to connecting member 26. Note that this is not a limitation, and tip member 25 may be connected directly to front barrel 21 without using connecting member 26.

[0083] The sleeve 27 is a member that holds the front end of the writing lead 15. The writing lead 15, which is advanced forward by the feeding mechanism 30, passes through the sleeve 27 and protrudes from the front end of the sleeve 27 (front end opening 20a). The sleeve 27 is fixed to a lead holder 37, which will be described later, and moves back and forth together with the lead holder 37 relative to the tip member 25. When the front end of the writing lead 15 wears down, the sleeve 27 abuts against a writing surface such as paper and retracts relative to the tip member 25. However, this is not a limitation, and the sleeve 27 may also be fixed to the tip member 25.

[0084] A crown 29 is attached to the rear end of the rear axle 23. As an example, a male thread formed on the outer periphery of the rear end of the rear axle 23 is threadedly engaged with a female thread formed on the inner periphery of the front end of the crown 29, thereby connecting the crown 29 to the rear axle 23. In this embodiment, by removing the crown 29 from the rear axle 23, a weight body 39 (described below) can be removed or replaced. An inward protrusion 29a protruding inward is provided at the rear end of the crown 29. The crown 29 has a through hole through which an operating portion 31a of a knock member 31 (described below) is inserted. This through hole is surrounded by the inward protrusion 29a. The crown 29 has the function of preventing the knock member 31 from slipping rearward out of the barrel 20.

[0085] The dispensing mechanism 30 of this embodiment is a mechanism for dispensing the tip of the writing lead 15 from the front end opening 20a of the barrel 20 (sleeve 27). The dispensing mechanism 30 of this embodiment includes a knock member 31, a lead pipe 32, a chuck 33, a connector 134, a receiving member 35, a fastener 136, a lead holder 37, a resilient member 38, a weight 39, and a pressing force increasing mechanism 40. The pressing force increasing mechanism 40 of this embodiment can be configured in the same way as the pressing force increasing mechanism 40 of the first embodiment, so a detailed description of the pressing force increasing mechanism 40 of this embodiment will be omitted.

[0086] A step 31e is formed between the operating portion 31a and the front portion 31b of the knock member 31. The step 31e is a surface facing rearward at the rear end of the front portion 31b. In this embodiment, the step 31e includes a plane extending perpendicular to the central axis A. When the user swings the barrel 20 back and forth, causing the weight body 39 to move forward, the step 31e receives an impact load from the weight body 39.

[0087] The lead pipe 32 is a component that stores the writing lead 15 therein. In this embodiment, when a user presses the knock member 31 forward, the lead pipe 32 receives this pressing force via the pressing force increasing mechanism 40. The lead pipe 32 also has the function of transmitting the pressing force from the knock member 31 to the connector 134. The lead pipe 32 is formed, for example, from resin. The chuck 33 is a component that grips the writing lead 15. The chuck 33 can move back and forth together with the lead pipe 32 and the connector 134. The connector 134 is a component that connects the lead pipe 32 and the chuck 33. In the illustrated example, the rear end of the connector 134 is inserted into the front end of the lead pipe 32, thereby fixing the connector 134 to the lead pipe 32. The rear end of the chuck 33 is inserted into the front end of the connector 134, thereby fixing the chuck 33 to the connector 134.

[0088] A resilient member 38 is disposed in front of the connector 134. The resilient member 38 is, for example, a coil spring. A receiving member 35 is disposed between the tip member 25 and the resilient member 38. The resilient member 38 is disposed in a compressed state between the front end of the connector 134 and the receiving member 35. The resilient member 38 constantly urges the core pipe 32, the chuck 33, and the connector 134 rearward relative to the barrel 20. When the chuck 33 holds the writing lead 15, the writing lead 15 is also urged rearward via the chuck 33 and the connector 134. The receiving member 35 is a member that receives the resilient force of the resilient member 38, and is pressed forward by the resilient force of the resilient member 38 and abuts against a step formed on the inner surface of the tip member 25.

[0089] The fastener 136 is an annular part located radially outward from the front portion of the chuck 33. The rear end of the fastener 136 abuts against the receiving member 35, restricting rearward movement of the fastener 136. The lead holder 37 is located in front of the chuck 33 and is a component that abuts against the outer surface of the writing lead 15 to hold the writing lead 15. The lead holder 37 is formed from an elastic material such as resin or rubber, and prevents the writing lead 15 from moving in the axial direction da when the chuck 33 is not holding the writing lead 15. In this embodiment, the lead holder 37 is configured to be movable back and forth within a predetermined range relative to the tip member 25.

[0090] The weight body 39 is a member that generates a pressing force that moves the chuck 33 forward. In the writing instrument 100 of this embodiment, the user can move the chuck 33 forward and advance the writing lead 15 either by directly pressing the knock member 31 forward or by swinging the writing instrument 100 back and forth, causing the weight body 39 to move back and forth. The weight body 39 is arranged to be movable back and forth relative to the barrel 20 and is configured to press the knock member 31 forward when it moves forward. The weight body 39 may press the knock member 31 directly when it moves forward, or it may press it indirectly via another member. The weight body 39 is arranged radially outward from at least a portion of the knock member 31. In particular, the weight body 39 is arranged radially outward from the operating portion 31a of the knock member 31 so as to surround the operating portion 31a. The weight body 39 is a cylindrical member having a central axis that coincides with the central axis A. The weight 39 is made of a material with a relatively high density, such as a metal material.

[0091] A gap is formed between the weight body 39 and the operating portion 31a, allowing the weight body 39 to move in the axial direction da relative to the operating portion 31a. In particular, when the user swings the writing instrument 100 along the axial direction da, the weight body 39 moves in the axial direction da relative to the operating portion 31a. When the weight body 39 moves forward and collides with the step portion 31e of the knock member 31, the impact load acting from the weight body 39 on the knock member 31 causes the knock member 31 to move forward. The weight body 39 is disposed between the step portion 31e of the knock member 31 and the inward protrusion 29a of the crown 29 in the axial direction da, and is movable in the axial direction da between the step portion 31e and the inward protrusion 29a. In other words, the range of movement of the weight body 39 in the axial direction da is defined by the step portion 31e and the inward protrusion 29a.

[0092] In this embodiment, the weight body 39 is located behind the rear end 32a of the lead pipe 32. In particular, even when the weight body 39 is located at the most forward position in its range of movement in the axial direction da, the entire weight body 39 is located behind the rear end 32a of the lead pipe 32. In conventional mechanical pencils with a weight body, the weight body is located radially outward from the lead pipe. Here, the weight body is formed of an opaque material, such as metal. Therefore, even if the barrel 20 and the lead pipe 32 were formed of a transparent material, such as a transparent resin, the presence of the weight body would prevent the user from viewing the interior of the lead pipe 32 from outside the barrel 20. In this embodiment, the weight body 39 is located behind the rear end 32a of the lead pipe 32. Therefore, the user can view the interior of the lead pipe 32 from outside the barrel 20, even if the barrel 20 and the lead pipe 32 are formed of a transparent material. Therefore, the remaining length of the writing lead 15 during use and the presence or absence of a spare lead in the lead pipe 32 can be confirmed from outside the barrel 20.

[0093] When the writing lead 15 is advanced by the feeding mechanism 30, the user presses the knock member 31 forward. This presses the lead pipe 32, the connector 134, and the chuck 33 forward via the pressing force increasing mechanism 40. That is, the lead pipe 32, the connector 134, and the chuck 33 move forward against the resilient force of the resilient member 38. In this embodiment, the user also swings the writing instrument 100 along the axial direction da, causing the weight body 39 to move forward and collide with the rear end of the connector 134, which also moves the lead pipe 32, the connector 134, and the chuck 33 forward against the resilient force of the resilient member 38.

[0094] When the knock member 31 is not pressed forward, the outer surface of the front portion of the chuck 33 abuts against the fastener 136 from the inside. This prevents the front portion of the chuck 33 from opening radially outward. This allows the front portion of the chuck 33 to grip the writing lead 15. When the chuck 33 moves forward, the writing lead 15 gripped by the chuck 33 moves forward, and the writing lead 15 is extended forward from the front end opening 20a of the tip member 25. When the chuck 33 moves further forward, the front portion of the chuck 33 moves forward relative to the fastener 136. This causes the front portion of the chuck 33 to open radially outward, and the writing lead 15 gripped by the front portion of the chuck 33 is released. At this time, the writing lead 15 is held by the lead holder 37.

[0095] When the user releases the pressure on the knock member 31, or when the weight 39 releases the pressure on the connector 134, the resilient force of the resilient member 38 moves the lead pipe 32, connector 134, and chuck 33 rearward. This causes the front portion of the chuck 33 to move toward the inside of the fastener 136, abutting against the fastener 136 and gripping the lead 15. At this time, the lead 15 is held by the lead holder 37, so rearward movement of the lead 15 is suppressed. In this way, with the writing instrument of this embodiment, the lead 15 is advanced forward from the front end opening 20a of the tip member 25.

[0096] Next, the operation of feeding out the writing lead 15 in the writing instrument 100 will be described mainly with reference to Figures 10 to 15. Figures 10 to 12 show the writing instrument 100 in a non-knocking state, and Figures 13 to 15 show the writing instrument 100 in a knocking state.

[0097] In the non-knocking state, the resilient force of the resilient member 38 urges the core pipe 32, the chuck 33, the connector 134, and the writing lead 15 rearward. In the non-knocking state, the slide member 50 is positioned on one side of the first direction d1. At this time, the longitudinal axis A of the pressing member 60 is Land the central axis A is θ1. The length of the pressing member 60 along the axial direction da is L1. Furthermore, the length along the axial direction da between the contact portion between the pressing surface 31c of the knock member 31 and the rear end portion 64 of the pressing member 60 and the rear end of the knock member 31 is L2.

[0098] When the user presses the knock member 31 forward, or when the user swings the barrel 20 back and forth and the weight body 39 collides with the step portion 31e of the knock member 31, the knock member 31 moves forward against the resilient force of the resilient member 38. The pressing member 60 receives a forward pressing force from the knock member 31 and moves forward. Also, receiving a pressing force from the knock member 31, the rear end portion 64 of the pressing member 60 moves toward the other side in the first direction d1. At this time, the position of the front end portion 62 of the pressing member 60 in the first direction d1 hardly changes. Therefore, the angle of the pressing member 60 with respect to the central axis A is changed. In particular, the relationship between the central axis A and the longitudinal axis A L The angle between the center axis A and the longitudinal axis A in the non-knock state L The angle between the two points is larger than the angle θ1.

[0099] As the angle of the pressing member 60 relative to the central axis A is changed, the abutment surface 68 of the pressing member 60 abuts against the abutment portion 58 of the sliding member 50 and presses the abutment portion 58. The sliding member 50 receives a pressing force from the pressing member 60 and moves forward, moving from one side to the other in the first direction d1. In particular, the sliding member 50 moves while the rear surface 52 slides along the inclined surface 20c formed on the inner surface of the barrel 20 (rear barrel 23). As the sliding member 50 moves forward, the pressed member 70 receives a pressing force from the sliding member 50 and moves forward. As a result, the pressed member 70, the core pipe 32, the chuck 33, the connector 134, and the writing lead 15 move forward against the resilient force of the resilient member 38. When the knock member 31 further moves forward, the writing instrument 100 enters the knock state shown in FIGS. 13 to 15 .

[0100] In this embodiment, the pressing force that presses the core tube 32, chuck 33, connector 134, and writing lead 15 forward is greater than the pressing force applied to the knock member 31. That is, in the writing instrument 100 of this embodiment, the core tube 32, chuck 33, connector 134, and writing lead 15 can be pressed forward against the elastic force of the elastic member 38 with a force that is greater than the pressing force applied by the user to the knock member 31 and the pressing force due to the impact load that the weight body 39 imparts to the knock member 31. In other words, the force required to press the knock member 31 forward is less than the elastic force of the elastic member 38.

[0101] The pressing force generated by the impact load of the weight body is smaller than the pressing force generated by the user pressing the knock member. Therefore, in conventional mechanical pencils with a weight body, the resilient force of the resilient member that urges the chuck backward is small so that even a small pressing force can move the chuck forward. This also reduces the gripping force of the chuck on the lead. In this case, the force (writing pressure) that presses the lead backward during writing can cause the lead to slip relative to the chuck and sink into the mechanical pencil. In contrast, this embodiment can achieve the following effects in addition to the effects of the first embodiment. In this embodiment, the force required to press the knock member 31 forward is smaller than the resilient force of the resilient member 38. Therefore, even if the resilient force of the resilient member 38 is large, the pressing force generated by the impact load of the weight body 39 allows the lead 15 to be properly dispensed. Therefore, it is possible to increase the gripping force of the chuck 33 on the writing lead 15, and it is possible to effectively prevent the writing lead from slipping against the chuck due to writing pressure.

[0102] In the writing instrument 100 of this embodiment, the weight body 39 is located behind the rear end 32 a of the core pipe 32 .

[0103] With this writing instrument 100, the weight 39 is located behind the rear end 32a of the lead pipe 32, so if the barrel 20 and the lead pipe 32 are made of a transparent material, the user can see the inside of the lead pipe 32 from outside the barrel 20. Therefore, the remaining length of the writing lead 15 in use, the presence or absence of a spare lead in the lead pipe 32, etc. can be confirmed from outside the barrel 20.

[0104] In the writing instrument 100 of this embodiment, the weight body 39 is disposed radially outward from at least a portion of the knock member 31.

[0105] According to this writing instrument 100, the knock member 31 and the weight body 39 can be arranged to overlap in the axial direction da, thereby reducing the space required to arrange the weight body 39. Therefore, the arrangement of the weight body 39 can prevent the writing instrument 100 from becoming larger.

[0106] In the writing instrument 100 of this embodiment, the knock member 31 has a step portion 31e, and when the weight body 39 moves forward, it collides with the step portion 31e and presses the knock member 31 forward.

[0107] With this writing instrument 100, the user's finger and the weight body 39 press the same knock member 31, so there is no need to provide an additional member to be pressed by the weight body 39. This prevents the writing instrument 100 from becoming too large. [Explanation of symbols]

[0108] 10 Writing instruments 15 Writing materials (writing cores) 17 Writing section 18 First Receiving Section 20 shaft cylinder 20a Front end opening 20b 2nd receiving part 20c slope 20d First guide surface 20e Second guide surface 21 Front axle 22 Center axis 23 rear axle 25 Tip member 26 Connecting member 27 Sleeve 29 Head crown 29a Inward protrusion 30 Maneuvering mechanism 31 Knock parts 31a Operation section 31b Front part 31c Pressing surface 31d side 31e Stepped section 32 Core pipe 32a rear end 33 Zipper 34 Engagement member 34a cam teeth 34b Protrusion 35 Receiving member 36 Rotating cam member 36a protrusion 36b Cam surface 37 Lead holder 38 Elastic members 39 Heavy body 40 Pressing force increasing mechanism 50 Slide member 51 Front 52 Rear 53 Side 54 Recess 56 Side (guide part) 58 Contact part 60 Pressing member 62 Front end 64 Rear end 66 Side 68 Contact surface 70 Pressurized member 72 Pressure-receiving surface 74 Support surface 81 Fulcrum 83 Emphasis 85 Point of action 100 writing instruments 134 Connector 136 Fasteners A Center axis AL Longitudinal axis da axial direction d1 1st direction d2 2nd direction

Claims

1. A writing instrument comprising: a barrel having a front end opening; a writing element disposed in the barrel; and a mechanism for feeding the tip of the writing element out from the front end opening, The dispensing mechanism has a knock member that can be pressed forward by a user and a resilient member that urges the writing member backward, a force required to press the knock member forward is smaller than the elastic force of the elastic member; the feeding mechanism has a pressing force increasing mechanism that increases the pressing force applied to the knock member and transmits the increased pressing force to the writing member when the knock member is pressed forward, The pressing force increasing mechanism includes: a pressing member whose angle with respect to the central axis of the barrel is changed in accordance with forward movement of the knock member; a slide member that moves forward by a pressing force from the pressing member and moves from one side to the other side in a first direction perpendicular to the central axis of the barrel; a pressing member that is movable forward by the pressing force from the sliding member.

2. the pressing member has a longitudinal axis in a cross section parallel to the central axis and the first direction, The writing instrument of claim 1 , wherein the angle between the central axis and the longitudinal axis increases as the knock member moves forward.

3. the knock member has a pressing surface that presses the pressing member, The writing implement according to claim 1 or 2, wherein the pressing surface extends from the front to the rear as it moves from the one side to the other side in the first direction.

4. An inclined surface is formed on the inner surface of the barrel, the inclined surface extending from rear to front as it moves from the one side to the other side in the first direction, The writing implement according to any one of claims 1 to 3, wherein when the knock member moves forward, the slide member moves along the inclined surface.

5. The writing implement according to any one of claims 1 to 4, wherein the slide member has a guide portion that guides the pressing member.

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