Disappearance-style notebook

Abstract

This invention provides a retractable writing instrument having an exterior member that is directly or indirectly attached to the operating member, which allows for more suitable long-term use. [Solution] A retractable writing instrument having a barrel, a pen tip, and an operating member, wherein at least a part of the pen tip protrudes outside the barrel when the operating member moves relative to the barrel, and the instrument has an exterior member to which the operating member or an intermediate member attached to the operating member is to be attached, the exterior member has a pressing plate portion, the attachment target member has a side wall portion and a rear wall portion located behind the side wall portion, the pressing plate portion extends from the side of the side wall portion to the rear of the rear wall portion, the tip end portion in the extension direction is a free end and can swing forward, and by pressing the pressing plate portion forward, the rear wall portion is pressed forward by the pressing plate portion.

Description

Technical Field

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

Background Art

[0002] A retractable writing instrument having a barrel, a pen tip member, and a knock member, and by operating the knock member, the tip of the pen tip member protrudes and retracts inside and outside the barrel is widely known. Such a retractable writing instrument includes a rear knock type retractable writing instrument in which a knock member is attached to the rear end side (tail end side) of the barrel, and a side knock type retractable writing instrument in which a knock member is attached to the side surface of the barrel.

[0003] In the rear knock type retractable writing instrument, the protruding state and the retracted state of the pen tip member are switched by the user pressing the knock member forward with the belly of the thumb or the like. As such a retractable writing instrument, for example, there is one disclosed in Patent Document 1.

[0004] The retractable writing instrument of Patent Document 1 has a protruding portion (a part of a cam member) that protrudes from the rear end of the barrel to the outside, and by the forward movement of this protruding portion, the pen tip protrudes and retracts inside and outside the barrel. Here, this retractable writing instrument has a clip body attached to the protruding portion. The clip body is a molded body made of synthetic resin, and a bottomed cylindrical tubular portion with an open front, a clip base protruding outward from the side surface of the tubular portion, and a clip body extending in the front-rear direction continuously with the protruding end of the clip base are integrally molded by synthetic resin. And this retractable writing instrument attaches the clip body to the protruding portion by fitting the tubular portion over the protruding portion, and by the user pressing the rear end portion of the tubular portion forward, the clip body and the protruding portion move forward together. That is, this retractable writing instrument makes the pen tip protrude and retract inside and outside the barrel by the user operating the protruding portion through the tubular portion attached to the protruding portion.

[0005] In addition, there is a retractable writing instrument with a rear-knock mechanism, disclosed in Patent Document 2. The retractable writing instrument of Patent Document 2 has a rod-shaped operating part, the rear part of which protrudes outward from the rear end of the barrel, and the pen tip retracts inward and outward when the user presses the rear end of the operating part with the pad of their thumb or the like. Furthermore, the retractable writing instrument of Patent Document 2 has an L-shaped clip, and a mounting hole for attaching the clip is provided on the side of the operating part. That is, by inserting a part of the clip into the mounting hole, the clip is attached to the operating part, and the clip extends outward from the inside of the mounting hole to the side of the operating part, then bends and extends forward (towards the pen tip).

[0006] As described above, in the rear-knock type retractable writing instruments of Patent Documents 1 and 2, the clip portion (clip member) is attached indirectly or directly via a cylindrical portion to an operating member (projection portion, operating part) that moves relative to the barrel during operation. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2024-135455 [Patent Document 2] Japanese Patent Publication No. 2023-180926 [Overview of the project] [Problems that the invention aims to solve]

[0008] In the structure described in Patent Document 1 above, the area near the base of the clip is prone to damage. As a result, the strength may decrease over time, causing the base of the clip body (the part close to the clip base) to break when attaching or detaching it from a breast pocket, etc.

[0009] Furthermore, in a structure like that described in Patent Document 2 above, when attaching or detaching it from a breast pocket or the like, force is applied to the connection between the operating part and the clip, causing the clip to unintentionally detach from the operating part. Such detachment becomes more likely to occur as the mounting hole widens with prolonged use, resulting in the problem of the clip frequently detaching unintentionally.

[0010] Furthermore, with the conventional retractable writing instruments described above, the parts that the user directly touches during operation (the cylindrical part, the operating part) can wear down due to repeated contact over time, leading to problems such as an unsightly appearance.

[0011] In other words, a rear-knock type retractable writing instrument, in which a clip member (clip portion) is directly or indirectly attached to an operating member that moves relative to the barrel, had room for further improvement from the standpoint of further suppressing damage and deterioration during prolonged use. To put it another way, a rear-knock type retractable writing instrument, in which an external component such as a clip is directly or indirectly attached to an operating member, had room for further improvement from the standpoint of making it more suitable for prolonged use.

[0012] Therefore, the object of the present invention is to provide a retractable writing instrument having an exterior member that is directly or indirectly attached to an operating member, which is more preferably capable of being used over a long period of time. [Means for solving the problem]

[0013] One aspect of the present invention for solving the above problems is a retractable writing instrument having a barrel, a pen tip, and an operating member, wherein at least a part of the pen tip protrudes outside the barrel when the operating member moves relative to the barrel, and the exterior member has an exterior member to which the operating member or an intermediate member attached to the operating member is to be attached, the exterior member has a pressing plate portion, the attachment target member has a side wall portion and a rear wall portion located behind the side wall portion, the pressing plate portion extends from the side of the side wall portion to the rear of the rear wall portion, the tip portion in the extension direction is a free end and can swing forward, and by pressing the pressing plate portion forward, the rear wall portion is pressed forward by the pressing plate portion, in a retractable writing instrument. The term "writing instrument" as used herein includes mechanical pencils, ballpoint pens, felt-tip pens and other inking tools, and electronic pens such as styluses, and encompasses all tools used for writing (drawing) letters, symbols, pictures, etc. (writing instruments in a broad sense). Furthermore, unlike capped pens where at least a portion of the pen tip is always located outside the barrel, a retractable writing instrument is one in which the movement of an operating mechanism switches between a state where at least a portion of the pen tip is located inside the barrel and a state where it is located outside the barrel.

[0014] According to this design, the pressure plate reduces the load caused by user knocking, thus suppressing the deterioration of the operating member and intermediate member that are attached to it over time.

[0015] Preferably, in a natural state where no external force is applied, there is a gap between the pressing plate portion and the rear wall portion.

[0016] Under these circumstances, the deterioration of operating components and intermediate components over time can be further suppressed.

[0017] Preferably, the pressing plate portion extends from the side toward the central axis in a plan view taken from the rear in the longitudinal direction of the central axis, with the middle portion of the extension portion positioned to coincide with the central axis, and the tip portion of the extension portion positioned beyond the central axis.

[0018] Under these circumstances, the manufacture of retractable writing instruments becomes easier, and manufacturing costs can be reduced, allowing retractable writing instruments to be offered to consumers at a low price.

[0019] Preferably, the exterior member has a first side wall portion and a second side wall portion, with the pressing plate portion positioned between the first side wall portion and the second side wall portion, and by pressing the pressing plate portion forward, the tip portion of the pressing plate portion moves below the rear ends of the first side wall portion and the second side wall portion.

[0020] In this configuration, the first and second side walls function as guides when the pressing plate swings, and the first and second side walls prevent unintended forces from being applied to the pressing plate from the side (in a direction intersecting the direction of swing). As a result, damage and deterioration of the pressing plate can be suppressed.

[0021] Preferably, the mounting member has a first raised portion, a second raised portion, a first groove, and a second groove, the rear portion of the first raised portion forms the rear wall, and the boundary portion between the first raised portion and the second raised portion has a step-forming surface, the first raised portion and the second raised portion are continuous such that their respective rear surfaces and respective side surfaces have a step through the step-forming surface, and in a plan view seen from the rear in the longitudinal direction of the central axis, the first groove and the The second groove is located on both sides of the first raised portion, and the front portion of the first side wall and the front portion of the second side wall are arranged inside the first groove and the second groove, respectively. In a plan view taken from the rear in the longitudinal direction of the central axis, when the direction from the first raised portion to the second raised portion is taken as the first direction, the pressing plate portion, the first side wall, and the front side surface of the second side wall in the first direction in their natural state face the step-forming surface.

[0022] This configuration prevents unintended misalignment of the exterior components and allows for a beautiful, integrated appearance of the rear end of the retractable writing instrument.

[0023] Preferably, the member to be attached has a member body and a target-side engaging piece that protrudes laterally from the member body. The exterior member has an exterior-side engaging portion, and the exterior-side engaging portion includes two engaging piece portions that engage with the target-side engaging piece. At least a part of the target-side engaging piece is disposed between the two engaging piece portions, and in a state of engaging with the two engaging piece portions, the exterior member is attached to the member to be attached. The target-side engaging piece and the two engaging piece portions allow relative movement in the attachment direction of the member to be attached and the exterior member, and restrict relative movement in the removal direction of the member to be attached and the exterior member. The exterior member is attached to the member to be attached in a snap-fit state.

[0024] According to such an aspect, unintentional detachment of the exterior member can be prevented (suppressed).

[0025] Preferably, in the front portion of the target-side engaging piece, a portion on one end side in a predetermined direction contacts a part of one of the engaging piece portions, and a portion on the other end side located on the opposite side in the predetermined direction contacts a part of the other engaging piece portion.

[0026] According to such an aspect, rattling (lateral play) of the exterior member can be prevented (suppressed).

[0027] Preferably, the exterior member has an exterior-side attachment portion and a clip portion, and the clip portion extends forward from the exterior-side attachment portion.

[0028] According to such an aspect, it is not necessary to separately form the exterior member and the clip, the number of parts can be reduced, and the manufacturing cost can be reduced. Therefore, the retractable writing instrument can be provided to consumers at a low price.

[0029] Preferably, the exterior member is made of metal and the member to be attached is made of resin.

[0030] According to such an aspect, wear and damage of the exterior member due to long-term use can be more reliably prevented.

[0031] The aspects described above can be dependent on each other, refer to some of their components, or substitute for some of their components, as long as they fall within the technical scope of the present invention. [Effects of the Invention]

[0032] According to the present invention, it is possible to provide a retractable writing instrument having an exterior member that is directly or indirectly attached to an operating member, which is more preferably capable of being used over a long period of time. [Brief explanation of the drawing]

[0033] [Figure 1] This is a cross-sectional view showing a retractable writing instrument according to an embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view showing a retractable writing instrument. [Figure 3] Figure 2 is a perspective view showing the shaft cylinder. [Figure 4] Figure 2 is a cross-sectional view showing the shaft cylinder. [Figure 5] Figure 2 shows the pressing member, with (a) being a perspective view and (b) being a cross-sectional perspective view. [Figure 6] Figure 2 shows the operating components, with (a) being a perspective view and (b) being a cross-sectional view. [Figure 7] Figure 2 shows the mounting support member, with (a) being a perspective view and (b) being a side view. [Figure 8] Figure 7 is a cross-sectional perspective view showing the mounting support member. [Figure 9] Figure 7 shows the area around the rear end of the mounting support member, with (a) being a perspective view and (b) being a side view. [Figure 10] Figure 7 is a rear view showing the area around the rear end of the mounting support member. [Figure 11] Figure 7 shows a partially cut section of the mounting support member, with (a) being a perspective view and (b) being a side view. [Figure 12] Figure 2 is a perspective view showing the exterior components. [Figure 13] Figure 12 is a perspective view showing the exterior component from a different direction. [Figure 14] This is an explanatory diagram showing a cutaway of the rear portion of the exterior member in Figure 12, illustrating how the rear plate forming section swings. [Figure 15] (a) is a perspective view showing the area around the rear portion of the exterior member in Figure 13, and (b) is a side view showing the area around the exterior-side engaging portion in (a). [Figure 16] Figure 13 is a cross-sectional view AA showing the exterior components. [Figure 17] Figure 1 is an explanatory diagram showing the assembly procedure for the writing instrument, and it should be assembled in the order of (a) and (b). [Figure 18] Figure 17 is followed by an explanatory diagram showing the assembly procedure for the writing instrument, which is assembled in the order of (a) and (b). [Figure 19] Figure 1 shows the area around the rear end of the writing instrument, with (a) being a perspective view and (b) being a rear view. [Figure 20] Figure 19(a) is a cross-sectional view of a writing instrument, shown by BB. [Figure 21] (a) is a perspective view showing the writing instrument of Figure 19(a) with the exterior members visible through it, and (b) is an explanatory diagram showing the writing instrument of (a) broken at the CC plane to show the main parts. [Modes for carrying out the invention]

[0034] Embodiments of the present invention will be described below. In the following description, the front and back will be defined as the pen tip side being the front and the tail end side being the rear.

[0035] As shown in Figures 1 and 2, the writing instrument 1 (retractable writing instrument) of this embodiment includes a barrel 2, a biasing member 3, a lead member 4, a pressing member 5, an operating member 6, a mounting auxiliary member 7 (intermediate member, mounting target member), and an exterior member 8.

[0036] As shown in Figures 3 and 4, the shaft cylinder 2 of this embodiment has a cylindrical front shaft portion 2a and a rear shaft portion 2b, respectively, and is a member formed by connecting these in the front-rear direction. That is, as shown in Figure 4, the rear portion of the front shaft portion 2a is fitted into the front portion of the rear shaft portion 2b from the front, and the threaded portions (engaging portions) formed on the outer circumferential surface of the front shaft portion 2a and the inner circumferential surface of the rear shaft portion 2b are screwed (engaged) together. In this way, the front shaft portion 2a and the rear shaft portion 2b are connected in a detachable manner.

[0037] This shaft cylinder 2 is a cylindrical body having length in the front-to-back direction, and as shown in Figures 3 and 4, it has a tapered portion 10, a front opening 11, a rear opening 12, a rear elongated hole portion 13, and a shaft-side projection portion 14.

[0038] The tapered portion 10 is formed on the front side of the shaft cylinder 2 and gradually narrows as it extends forward.

[0039] The front opening 11 is provided at the front end of the barrel 2 (front part 2a of the barrel), and is a hole that connects the internal space to the outside, and is an opening from which a part of the pen tip forming part 25 (see Figure 1, etc.) can extend and retract. The rear opening 12 is provided at the rear end of the shaft cylinder 2 (rear part 2b of the shaft cylinder) and is a hole that connects the internal space to the outside. The rear elongated hole 13 is provided on the lateral rear end side of the shaft cylinder 2 (rear side portion 2b of the shaft cylinder), and is an elongated hole portion that extends forward from the rear end of the shaft cylinder 2, penetrating the side wall portion of the shaft cylinder 2. In this embodiment, the rear elongated hole 13 is a hole with a substantially rectangular shape when viewed from the side (detailed illustration is omitted).

[0040] The shaft-side projection 14 is a roughly hemispherical, rounded projection that protrudes outward from the side surface (outer surface of the side wall portion) of the shaft cylinder 2. In this embodiment, the shaft-side projection 14 is formed at a position away from the front end of the rear elongated hole portion 13, and is formed so that the shaft-side projection 14 and a part of the rear elongated hole portion 13 are spaced apart in the front-rear direction.

[0041] Furthermore, as shown in Figure 4, the shaft cylinder 2 has an internal shaft-side contact portion 17, a constricted projection portion 18, a shaft cylinder-side engaging portion 19, and a shaft-side engaging groove portion 20.

[0042] The shaft-side contact portion 17 is a part formed slightly behind the front end inside the shaft cylinder 2 (shaft cylinder front portion 2a), and is a surface that intersects with the front-rear direction and faces the rear. In detail, a part of the inner circumferential surface of the shaft cylinder 2, which is aligned in the front-rear direction, and another part are formed with a step, and the shaft-side contact portion 17 is located at the boundary between these two stepped parts.

[0043] The constricted projection 18 is a projection that protrudes inward from the inner circumferential surface of the shaft cylinder 2 and is a continuous annular projection around the central axis α1. The portion enclosed by the constricted projection 18 becomes a narrowed portion (constricted section) within the internal space of the shaft cylinder 2. In other words, the thickness of the circumferential wall of the portion enclosed by the constricted projection 18 is formed to be thicker than the thickness of the circumferential wall of the adjacent portion in the front-to-back direction, and it becomes narrower in diameter (thinner) than the adjacent portion. Furthermore, the central axis α1 is a hypothetical line that partially coincides with the central axis of the writing instrument 1; in other words, it is a hypothetical line (straight line) that extends longitudinally from the central axis of the writing instrument 1. In this embodiment, the central axis α1 of the writing instrument 1 is also the central axis of the barrel 2, and is a hypothetical straight line that passes through the center of the cross-section of each part in the main portion of the barrel 2.

[0044] The shaft cylinder side engagement portion 19 has a plurality of first raised portions 19a, groove portions 19b between the raised portions, and second raised portions 19c. The first raised portion 19a is a part that rises inward from the inner circumferential surface of the shaft cylinder 2 and extends in the front-rear direction, with its front end surface being an inclined surface. In this embodiment, a plurality of first raised portions 19a are arranged at intervals in the circumferential direction (around the central axis α1) of the inner circumferential surface of the shaft cylinder 2. The inter-ridge groove 19b is a groove formed between the two first ridges 19a and extending in the front-rear direction. In this embodiment, multiple inter-ridge grooves 19b are arranged at intervals in the circumferential direction on the inner surface of the shaft cylinder 2. The rear end portion (groove bottom portion) of the inter-ridge groove 19b is located behind the front end portion of the inter-ridge groove 19b. The second raised portion 19c is formed between the two first raised portions 19a, protrudes inward from the inner circumferential surface of the shaft cylinder 2, extends in the front-rear direction, and has an inclined front end surface. This second raised portion 19c is shorter in length (thinner in thickness) than the first raised portion 19a. In this embodiment, multiple second raised portions 19c are arranged at intervals in the circumferential direction of the inner circumferential surface of the shaft cylinder 2. More specifically, these first raised portion 19a, inter-raised groove portion 19b, and second raised portion 19c are arranged in the circumferential direction of the inner surface of the shaft cylinder 2 in the order of first raised portion 19a, inter-raised groove portion 19b, first raised portion 19a, second raised portion 19c, first raised portion 19a, inter-raised groove portion 19b, ... This shaft cylinder-side engaging portion 19 is an engaging portion that engages with the pressing-side engaging portion 32 (see Figure 5, etc.) and the operating-side engaging portion 51 (see Figure 6, etc.), which will be described later.

[0045] The shaft-side engagement groove 20 is formed on the rear side inside the shaft cylinder 2 and is a groove that is recessed away from the central axis α1 and extends in the front-rear direction (see Figures 4 and 17(b)). As shown in Figure 4, this shaft-side engagement groove 20 is formed on the opposite side of the rear elongated hole 13, straddling the central axis α1.

[0046] As shown in Figure 2, the biasing member 3 is a compression coil spring, and when compressed, it is a member that exerts an elastic restoring force in the opposite direction to the compression direction. In this embodiment, the biasing member 3 is a member that constantly biases the core member 4 backward (details will be described later).

[0047] As shown in Figures 1 and 2, the core member 4 is a rod-shaped member that extends as a whole, and has a pen tip forming portion 25 (pen tip portion) and an ink storage portion 26 (coating liquid storage portion), which are integrally connected to each other.

[0048] The pen tip forming section 25 is the part that can apply the supplied ink (coating liquid) to an object to be coated, such as paper, and in this embodiment, a ballpoint pen tip is used. That is, the core member 4 in this embodiment is a ballpoint pen refill, and the writing instrument 1 in this embodiment is a ballpoint pen (a rear-click type ballpoint pen).

[0049] The ink storage section 26 is a cylindrical member, and is the part in which ink is stored. In this embodiment, the core member 4 has the rear portion of the pen tip forming section 25 inserted through the front opening of the ink storage section 26, with the pen tip forming section 25 fixed to the ink storage section 26, and ink is supplied to the pen tip forming section 25 from inside the ink storage section 26.

[0050] In this embodiment, the ink storage portion 26 has a step formed by making a portion of the front side narrower (shorter in the direction of the cross-section's expansion) than the portion adjacent to the rear side, and a core-side contact wall portion 28 is located between these. This core-side contact wall portion 28 is a surface that intersects (orthogonal in this embodiment) the front-rear direction, is a surface facing forward, is formed in front of the center in the longitudinal direction of the core member 4, and is a surface located at the boundary between two portions of different thicknesses.

[0051] As shown in Figure 5, the pressing member 5 is a resin member formed integrally with a front cylindrical portion 5a and a rear cylindrical portion 5b of different diameters. More specifically, both the front cylindrical portion 5a and the rear cylindrical portion 5b are cylindrical parts extending in the front-rear direction. The front cylindrical portion 5a is formed to be thicker than the rear cylindrical portion 5b, and the rear cylindrical portion 5b extends rearward from the rear end of the front cylindrical portion 5a.

[0052] The pressing member 5 has a pressing-side engaging portion 32, a pressing-side cam portion 33, and a pressing-side locking projection portion 34.

[0053] The pressing-side engaging portion 32 is composed of a plurality of engaging projections 32a that protrude outward from the outer circumferential surface of the front cylindrical portion 5a. As described above, this pressing-side engaging portion 32 is an engaging portion that engages with the shaft cylinder-side engaging portion 19 (see Figure 4).

[0054] The pressing cam portion 33 is formed at the rear end of the front cylindrical portion 5a and has a convex portion 33a that protrudes toward the rear and a concave portion 33b formed between the two convex portions 33a. The pressing cam portion 33 is a portion in which the convex portions 33a and concave portions 33b are alternately arranged around the central axis α1 (the circumferential direction of the shaft cylinder 2, and the circumferential direction of the outer surfaces of the front cylindrical portion 5a and the rear cylindrical portion 5b). This pressing cam portion 33 is continuous in an annular shape around the central axis α1 and is formed to surround the front portion of the rear cylindrical portion 5b. For the sake of drawing, only some of the convex portions 33a and concave portions 33b are labeled with reference numerals, and the reference numerals for others are omitted. Also, in the following description, if there are multiple similar parts, the reference numerals will be omitted as necessary.

[0055] The pressing-side locking projection 34 is a projection formed slightly forward of the rear end portion of the pressing member 5 (rear cylindrical portion 5b), protruding outward from the outer circumferential surface and forming a continuous annular (ring-shaped) projection around the central axis α1. In this embodiment, the pressing-side locking projection 34 has a rounded shape without sharp corners.

[0056] Here, as shown in Figure 5(b), the pressing member 5 has a front opening 37 located on the front end side and a rear opening 38 located on the opposite rear end side, and is a cylindrical body in which the internal space and the outside are in communication via the front opening 37 and the rear opening 38. The pressing member 5 also has a front tapered portion 40, a front groove portion 41, and an internal contact wall portion 42 inside.

[0057] The front tapered portion 40 forms the portion of the inner circumferential surface of the pressing member 5 from the front end to slightly behind, and is a tapered surface portion that narrows in diameter as it approaches the rear. The front groove portion 41 is a continuous annular groove portion around the central axis α1, and is formed slightly behind the rear end of the front tapered portion 40. This front groove portion 41 is a groove that is recessed outward in the radial direction (direction perpendicular to the central axis α1) of the pressing member 5, and in this embodiment, it is a groove with a rounded shape. That is, the bottom portion of the front groove portion 41 is a curved surface recessed in an arc shape along the front-rear direction, and the part closest to the center in the front-rear direction is the most recessed part. Note that there may be more than one front groove portion 41, and if the pressing member 5 has a structure with multiple front groove portions 41, the multiple front groove portions 41 may be formed so that they are aligned in the front-rear direction.

[0058] The internal contact wall portion 42 is a surface that intersects the front-rear direction and is formed near the boundary between the front cylindrical portion 5a and the rear cylindrical portion 5b, and is a surface that faces forward. Here, the portion adjacent to the front side and the portion adjacent to the rear side of the internal contact wall portion 42 are continuous via the internal contact wall portion 42 and are formed to have a step. In other words, the internal contact wall portion 42 is a surface located in the stepped portion formed on the inner circumferential surface of the pressing member 5, and more specifically, it is a surface located between a part and another part of the inner circumferential surface of the pressing member 5 which is arranged to have a step.

[0059] As shown in Figure 6, the operating member 6 has a front portion 6a, an intermediate portion 6b, and a rear portion 6c from the front, and these are integrally formed resin members. As shown in Figure 6(b), the operating member 6 of this embodiment has a front opening 47 on the front end side that connects the internal space to the outside, and is a bottomed cylindrical member with the rear side closed.

[0060] As shown in Figure 6, the intermediate section 6b is a part that is narrower than the front section 6a, and the rear section 6c is a part that is narrower than the intermediate section 6b. In other words, the operating member 6 becomes progressively narrower as it moves towards the rear. The front section 6a and the intermediate section 6b are generally cylindrical in shape, while the rear section 6c is generally polygonal (in this embodiment, a hexagonal tube with a bottom; detailed illustration is omitted).

[0061] As shown in Figure 6, the operating member 6 has an operating-side engaging portion 51, an operating-side cam portion 52, and a first locking projection portion 53.

[0062] The operating-side engaging portion 51 is composed of a plurality of engaging projections 51a, each of which protrudes outward from the outer peripheral surface around the front end of the front portion 6a. This operating-side engaging portion 51 is an engaging portion that engages with the shaft cylinder-side engaging portion 19 (see Figure 4) described above.

[0063] The operating cam portion 52 is formed on the front end surface of the operating member 6 (front portion 6a) and has a convex portion 52a that protrudes forward and a recess 52b formed between the two convex portions 52a. The operating cam portion 52 is formed to be continuous in an annular shape on the outside of the front opening 47, and the convex portions 52a and recess 52b are arranged alternately around the central axis α1.

[0064] The first locking projection 53 is a projection formed on the intermediate portion 6b, protruding outward from the outer circumferential surface and continuing in an annular (circular) shape around the central axis α1. In this embodiment, the first locking projection 53 has a rounded shape without sharp corners.

[0065] Furthermore, as shown in Figure 6(b), the operating member 6 has a second locking projection 54 inside. The second locking projection 54 is formed on the front portion of the operating member 6 (front portion 6a), protruding inward from the inner circumferential surface of the operating member 6, and is a continuous annular (ring-shaped) projection around the central axis α1. In this embodiment, the second locking projection 54 has a rounded shape without sharp corners.

[0066] As shown in Figures 7 and 8, the mounting support member 7 has a support member body portion 60 (target member body) and an exterior engaging portion 61 (target side engaging portion), and is a resin member in which each part is integrally molded. In other words, the mounting support member 7 is a member formed using an appropriate resin (synthetic resin) as the main raw material, and in this embodiment, ABS (acrylonitrile butadiene styrene) resin is used as the main raw material.

[0067] As shown in Figure 8, the auxiliary member body 60 is a bottomed cylindrical member with an open front, and has a side wall forming portion 63 (side wall portion) that forms the side wall portion, and a rear wall forming portion 64 that closes the rear end side of the side wall forming portion 63. The auxiliary member body 60 also has a front opening 65 on its front end side that connects the internal space to the outside.

[0068] As shown in Figures 7 and 8, the side wall forming portion 63 is a wall portion that is continuous in an annular shape around the central axis α1. The central axis α1 is also the central axis of the auxiliary member main body portion 60, and is also a hypothetical straight line passing through the center of the cross-section of each part in the main portion of the auxiliary member main body portion 60.

[0069] The rear wall forming portion 64 has an uneven portion in the part that forms the outer surface, and in detail, as shown in Figure 7, it has a first raised portion 71, a second raised portion 72, a first groove portion 73, and a second groove portion 74. In the following explanation, the first direction is defined as the direction perpendicular to the longitudinal direction of the central axis α1, moving from the first raised portion 71 towards the second raised portion 72, and the second direction is defined as the opposite direction. Furthermore, in the following explanation, the third direction is defined as the direction perpendicular to the longitudinal direction (front-back direction) of the central axis α1, and perpendicular to both the first and second directions.

[0070] The first raised portion 71 is a lumpy portion that protrudes (bumps) towards the rear, and in this embodiment, its general shape is approximately that of a rectangular parallelepiped. This first raised portion 71 has a first raised rear wall portion 71a (rear wall portion) that forms the rear wall portion and a plurality (three in this embodiment) of first raised side wall portions 71b that form the side wall portion.

[0071] The rear surface of the first raised portion 71 (the rear surface of the first raised rear wall portion 71a) is a curved surface that curves so as to be slightly convex toward the rear. The first raised rear wall portion 71a also has a rear recess 77 on its rear surface (the upper surface in Figures 9(a) and 9(b)). The rear recess 77 is a recess that is concave toward the front, and in this embodiment, it is a substantially hemispherical recess.

[0072] The first raised portion 71 is formed by a plurality of first raised side wall portions 71b that are continuous in the circumferential direction, with one of its four sides (one of the four sides) being integrated with the second raised portion 72. More specifically, in a plan view from the rear (see Figure 10), the three first raised side wall portions 71b are connected in a roughly U-shape, forming the side wall portion of the first raised portion 71.

[0073] The second raised portion 72 is a lumpy portion that is raised (protrudes) so as to be convex toward the rear, and in this embodiment, its general shape is approximately that of a rectangular parallelepiped.

[0074] In this embodiment, the auxiliary member body portion 60 has a lateral projection 63a that protrudes outward in the first direction from a part of the side wall forming portion 63 (see Figure 7), and this lateral projection 63a is a portion that is roughly rectangular in shape and extends in the front-rear direction. Furthermore, in this embodiment, the second raised portion 72 has an end portion in the first direction that protrudes laterally outward, and the lower portion of the protruding portion is formed to be integrated with the upper end portion of the lateral projection 63a.

[0075] This second raised portion 72 has a second raised rear wall portion 72a that forms the rear wall portion and a plurality (four in this embodiment) second raised side wall portions 72b that form the side wall portion. The rear surface of the second raised portion 72 (the rear surface of the second raised rear wall portion 72a) is a curved surface that curves so as to be slightly convex toward the rear. In addition, the four second raised side wall portions 72b are located at both ends in the first direction, and the other two are located at both ends in the third direction, each forming a side wall portion.

[0076] Here, the rear surface of the second raised portion 72 is located further back than the rear surface of the first raised portion 71. These are continuous via a second raised side wall portion 72b and are formed to have a step. Similarly, the side surface of the second raised portion 72 located on one end side in the third direction is located outward in the same direction than the side surface of the first raised portion 71 in the same direction. Also, the side surface of the second raised portion 72 located on the other end side in the third direction is located outward in the same direction than the side surface of the first raised portion 71 in the same direction. Each of these is continuous via a second raised side wall portion 72b and is formed to have a step.

[0077] Based on the above, one second raised side wall portion 72b located at the boundary between the first raised portion 71 and the second raised portion 72 forms a step-forming surface portion 79 located at the boundary between two portions with a step. The stepped surface portion 79 is a surface that intersects (orthogonal in this embodiment) the first direction and the second direction, and is a surface that faces the base end side in the first direction (the tip side in the second direction).

[0078] The first groove 73 and the second groove 74 are recessed groove portions that extend forward, as shown in Figures 9 and 10, and extend linearly along the first direction. More specifically, as shown in Figure 10, the first groove 73 and the second groove 74 extend from the edge portion of the auxiliary member body 60 to the step-forming surface portion 79 in a plan view from the rear.

[0079] Furthermore, the first groove 73 and the second groove 74 are located on either side of the first raised portion 71 when viewed from the rear in a plan view. In other words, one of the first groove 73 and the second groove 74 is adjacent to one end of the first raised portion 71 in the third direction, and the other is adjacent to the other end in the same direction. Furthermore, a portion of the groove wall of both the first groove 73 and the second groove 74 is formed by the first raised side wall portion 71b.

[0080] As shown in Figures 9(a) and 9(b), the groove bottoms of the first groove 73 and the second groove 74 are adjacent to the front end portion (lower end portion in Figures 9(a) and 9(b)) of the first raised portion 71 in the third direction. In other words, the position of the groove bottoms of the first groove 73 and the second groove 74 in the front-rear direction (position in the up-down direction in Figures 9(a) and 9(b)) is the same as the position in the front-rear direction of the front end portion of the first raised portion 71.

[0081] As shown in Figure 7, the exterior engagement portion 61 is a part in which an engagement piece forming portion 84 (target-side engagement piece) that protrudes outward in a second direction from the side surface (outer surface surface of the side wall forming portion 63) of the auxiliary member main body portion 60 and a block-like portion 85 are integrally formed.

[0082] As shown in Figure 11, the engagement piece forming portion 84 is a plate-shaped portion extending in the front-rear direction, and has an introduction guide portion 84a and a forming piece main body portion 84b from the rear end side (upper end side in Figure 11).

[0083] The introduction guide section 84a is a roughly trapezoidal plate-shaped portion with thickness in the second direction, and has a tapered shape in which the width gradually increases (the length in the third direction increases) as it moves forward. The formed piece body portion 84b is a roughly rectangular plate-shaped portion having thickness in the second direction, and more specifically, a roughly rectangular plate-shaped portion extending in the front-rear direction (up-down direction in Figure 11). This formed piece body portion 84b has a first engaging portion 91 and a second engaging portion 92 at both ends in the width direction (third direction).

[0084] Here, as shown in Figure 11(b), the engaging piece forming portion 84 is a part that is symmetrical on both sides of the central portion in the width direction (third direction), and the first engaging portion 91 and the second engaging portion 92 are also parts that are symmetrical in the width direction. For this reason, only the second engaging portion 92, one of the two, will be described in detail, and the other, the first engaging portion 91, will be omitted as it would be redundant to provide a detailed explanation.

[0085] As shown in Figure 11, the second engaging portion 92 has a first restricting piece 95, a second restricting piece 96, a locking wall 97, and a contact surface 98 from the rear side (upper side in Figure 11), and these are arranged with a gap between them in the front-rear direction.

[0086] The first restricting piece 95 and the second restricting piece 96 are protruding portions that project outward in the third direction, and both are substantially triangular plate-shaped portions with thickness in the second direction, with a rear surface that is inclined. More specifically, the rear surfaces of both the first restricting piece 95 and the second restricting piece 96 are inclined surfaces that slope outward in the third direction as they move forward. Furthermore, the front surfaces of the first restricting piece 95 and the second restricting piece 96 are surfaces that intersect (orthogonal in this embodiment) with the front-rear direction and face forward. In detail, the first restricting piece 95 and the second restricting piece 96 in this embodiment are substantially triangular portions with a corner missing, formed between the inclined rear surface and the flat front surface of the protruding end portion.

[0087] The locking wall portion 97 is a roughly rectangular plate-shaped portion that extends elongated in the front-rear direction, with the rear side surface intersecting (orthogonal in this embodiment) the front-rear direction, and the outer side surface being parallel to the front-rear direction. The maximum length of the locking wall portion 97 in the third direction (the maximum length of each portion in the third direction) is shorter than the maximum length of the first restricting piece portion 95 and the second restricting piece portion 96 in the third direction (the length of the front side surface in the third direction).

[0088] The contact surface portion 98 is continuous with the lower end portion of the outer side surface of the locking wall portion 97, intersects with the front-rear direction (orthogonal in this embodiment), and faces the rear.

[0089] As shown in Figure 7, the lumpy portion 85 is a roughly rectangular parallelepiped-shaped part, and more specifically, it has a shape in which a part of the corner of the rear portion (upper portion in Figure 7) is missing. More specifically, the lumpy portion 85 has a rectangular truncated base shape around the rear end, and its front portion is a roughly rectangular parallelepiped-shaped lumpy portion extending in the front-rear direction. In this embodiment, the lumpy portion 85 has recesses formed on the sides located on both sides in the third direction, which are indented in the same direction (one of the recesses is not shown in Figure 7).

[0090] As shown above, as indicated in Figures 7(a) and 11, a first insertion space 100 and a second insertion space 101 are formed between the inner surface of the block-like portion 85 and the outer surface of the side wall forming portion 63, on both sides of the engaging piece forming portion 84. The first insertion space 100 and the second insertion space 101 are gap portions that are open on the rear (upward in Figures 7 and 11) and on the outside in the third direction. Although not particularly limited, each part of the mounting support member 7 described above may be chamfered to give it a rounded shape.

[0091] Furthermore, as shown in Figure 8, the auxiliary member body portion 60 has an auxiliary locking projection portion 103 inside. The auxiliary locking projection 103 is formed on the front portion of the auxiliary member body 60, protruding inward from the inner circumferential surface of the auxiliary member body 60, and is a continuous annular (ring-shaped) projection around the central axis α1. In this embodiment, the auxiliary locking projection 103 is formed slightly behind the front opening 65 (near the front end) and has a rounded shape without sharp corners.

[0092] As shown in Figures 12 and 13, the exterior member 8 has an exterior mounting portion 107 and a clip portion 108, and these are integrally formed members. The exterior member 8 in this embodiment is a metal member mainly made of an appropriate metal such as iron or stainless steel, and is formed by bending a metal plate or the like.

[0093] As shown in Figures 12 and 13, the exterior mounting portion 107 includes a pressing plate portion 110, a first side wall portion 111, a second side wall portion 112, and an exterior engaging portion 113 (see Figure 13).

[0094] The pressing plate portion 110 has a side plate forming portion 110a extending in the front-rear direction (up-down direction in Figures 12 and 13), a curved portion 110b that curves and extends toward a first direction as it moves toward the rear, and a rear plate forming portion 110c that extends toward the front end in the same direction along the first direction. The rear end of the side plate forming portion 110a and the front end portion of the curved portion 110b are continuous, and the end portion of the curved portion 110b in the first direction and the base end portion of the rear plate forming portion 110c are continuous, and these are formed as a single unit.

[0095] As shown in Figure 13, the first side wall portion 111 has a main side wall portion 111a extending in the front-rear direction and a protruding piece portion 111b projecting in the first direction from the rear side portion of the main side wall portion 111a. That is, as shown in Figure 14, the first side wall portion 111 has a roughly L-shaped plate form when viewed from the side (when viewed from the third direction). As shown in Figures 12 and 13, the second side wall portion 112 is substantially the same shape as the first side wall portion 111, and most of it is a portion that is spaced apart from the first side wall portion 111 in the third direction. That is, the second side wall portion 112, like the first side wall portion 111, has a side wall main body portion 112a that extends in the front-rear direction and a protruding piece portion 112b that protrudes in the first direction from the rear side portion of the side wall main body portion 112a.

[0096] In this embodiment, as shown in Figure 14, the tip portion (the tip portion in the first direction) of the rear plate forming portion 110c of the pressing plate portion 110 is a free end, and it is swingable between the first side wall portion 111 and the second side wall portion 112 (the second side wall portion 112 is not shown in Figure 14). That is, the pressing plate portion 110 is elastically deformable, and as shown in Figure 14, it moves forward when a person presses it forward (downward in Figure 14) with their finger or the like, and returns to its original position when the person releases their finger or the like and the pressure is released.

[0097] As shown in Figure 15, the exterior-side engaging portion 113 has a first engaging piece portion 113a (engaging piece portion) and a second engaging piece portion 113b (engaging piece portion). The first engaging piece 113a and the second engaging piece 113b project outwards from the inner portion of the first side wall 111 and the inner portion of the second side wall 112, respectively, in a direction toward each other. More specifically, as shown in Figures 15(a) and 16, the first engaging piece 113a and the second engaging piece 113b project outwards in a diagonal direction that is toward the inward direction in the third direction and toward the tip side in the second direction.

[0098] In this embodiment, the exterior member 8 is a member that is symmetrical on both sides of the central portion in the third direction, and the first engaging piece 113a and the second engaging piece 113b are also symmetrical in the third direction. For this reason, only the first engaging piece 113a, one of the two, will be described in detail, and the other, the second engaging piece 113b, will be omitted as it would be redundant to provide a detailed description.

[0099] As shown in Figures 15(a) and 15(b), the first engaging piece 113a has a first restricting piece 115 and a second restricting piece 116 from the rear side (upper side in Figures 15(a) and 15(b)), and these are arranged with a gap between them in the front-rear direction.

[0100] The first restricting piece 115 and the second restricting piece 116 are protruding portions that project in the direction of projection of the first engaging piece 113a, and are generally triangular plate-shaped portions. The rear surfaces of both the first restricting piece 115 and the second restricting piece 116 are surfaces that intersect (orthogonal in this embodiment) with the front-rear direction, and are surfaces that face the rear. In addition, the front surfaces of the first restricting piece 115 and the second restricting piece 116 are inclined surfaces that slope toward the base end in the projection direction as they move forward. Furthermore, a rounded corner portion is formed at the point where the protruding end portion of the rear surface and the rear end portion of the front surface are continuous.

[0101] As shown in Figures 12 and 13, the clip portion 108 has a clip body portion 108a and a clamping projection forming portion 108b (see Figure 13).

[0102] The clip body portion 108a has an outer wall portion 122, two clip side wall portions 123 and 124, and a front side wall portion 125.

[0103] The outer wall portion 122 is a vertical plate-like portion located at the end in the second direction, has thickness in the same direction, and extends in the front-to-back direction (up-to-down direction in Figures 12 and 13). The two clip sidewall portions 123 and 124 are portions that protrude in a first direction from both ends in the width direction of the outer wall portion 122. That is, the outer wall portion 122 and the two clip sidewall portions 123 and 124 have a roughly U-shaped cross-section (detailed illustration omitted) and extend in the front-rear direction. Furthermore, a portion of the front end of the two clip sidewall portions 123 and 124 has a longer protruding length compared to the rear end.

[0104] The front wall portion 125 is located at the front end of the clip body portion 108a and protrudes in a first direction from the front end of the clip body portion 108a. In this embodiment, it has a rounded shape that is convex forward. In this embodiment, the rear portions of the front wall portion 125 located at both ends in the third direction are continuous with the front portions of the two clip side wall portions 123 and 124, forming a series of wall portions. For this reason, the front end portion of the clip portion 108 in this embodiment has a rounded shape.

[0105] As shown in Figure 13, the clamping projection forming portion 108b is a curved plate-shaped portion that is curved so as a whole it is convex toward the first direction, and has a clamping projection body 128 and a connecting portion 129, and is a portion formed so that these are integrated together. The clamping projection body 128 is a substantially polygonal plate-shaped portion, and the connecting portion 129 is a portion that is formed to be thinner than the clamping projection body 128 in the third direction. The clamping projection forming portion 108b extends cantileveredly from the front side wall portion 125 toward the rear and is pivotable relative to the front side wall portion 125. As a result, when the clamping projection body 128 is pressed in the second direction, the clamping projection body 128 moves in the second direction, causing the clamping projection forming portion 108b to elastically deform, and when the pressure is released, it returns to its original shape.

[0106] Next, the manufacturing method of the writing instrument 1 of this embodiment will be described.

[0107] (Connection body formation process) When manufacturing the writing instrument 1 of this embodiment, a process is carried out to form a connecting body that links the pressing member 5 and the operating member 6, as shown in Figure 17(a). That is, the rear cylindrical portion 5b (see Figure 5) of the pressing member 5 is inserted into the interior of the operating member 6 from the front opening 47 (see Figure 6) of the operating member 6, and is positioned inside the operating member 6. At this time, as shown in Figure 1, the pressing-side locking projection 34 of the pressing member 5 moves over the second locking projection 54 of the operating member 6 and moves to the rear side of the second locking projection 54. Also, the pressing-side cam portion 33 of the pressing member 5 and the operating-side cam portion 52 of the operating member 6 become engaged with each other. As a result, the pressing member 5 and the operating member 6 are able to rotate relative to each other around the central axis α1, and are connected in a manner that restricts relative movement in the direction of separation. The formed connected body is attached to an assembly jig (not shown).

[0108] (Inside cylinder arrangement process) Next, as shown in Figures 17(a) and 17(b), a step is performed to position a part of the connecting body inside the rear part 2b of the shaft cylinder. Specifically, as shown in Figure 17(a), the front part 2a of the shaft cylinder (see Figure 3, etc.) is removed from the rear part 2b of the shaft cylinder, and the rear part 2b of the shaft cylinder and the connecting body are moved relative to each other so that they approach the connecting body attached to an assembly jig (not shown). Then, the connecting body is inserted into the rear part 2b of the shaft cylinder through the front opening of the rear part 2b of the shaft cylinder, and by moving the connecting body and the rear part 2b of the shaft cylinder relative to each other, as shown in Figure 17(b), the majority of the connecting body is positioned inside the rear part of the rear part 2b of the shaft cylinder.

[0109] At this time, the connecting body is configured such that the pressing-side engaging portion 32 of the pressing member 5 and the operating-side engaging portion 51 of the operating member 6 are engaged with the shaft cylinder-side engaging portion 19 (see Figure 4) of the rear shaft cylinder portion 2b. In addition, the rear portion of the operating member 6 (the upper portion in Figure 17(b)) protrudes outward from the rear opening 12 located at the rear end of the rear shaft cylinder portion 2b.

[0110] (Temporary installation process of intermediate components) Next, as shown in Figure 17(b), the mounting support member 7 is temporarily attached to the operating member 6 of the connecting body. That is, the rear portion 6c of the operating member 6 (see Figure 6) is inserted into the interior of the mounting support member 7 through the front opening 65 (see Figure 8) of the mounting support member 7, and is positioned inside the mounting support member 7.

[0111] At this time, the lateral projection 63a of the auxiliary member body 60 is engaged with the shaft-side engagement groove 20 of the rear shaft portion 2b, so that the lateral projection 63a is inserted into the shaft-side engagement groove 20 (see Figures 17(b) and 18(a)). Here, the lateral projection 63a is formed on a part of the outer circumferential surface of the auxiliary member body 60, around the end in the first direction. Similarly, the shaft-side engagement groove 20 is formed on a part of the outer circumferential surface of the rear shaft portion 2b, around the end in the first direction. Therefore, by simply engaging the lateral projection 63a with the shaft-side engagement groove 20, the worker can temporarily install the mounting auxiliary member 7 without having to finely adjust its orientation or position. In other words, the lateral projection 63a and the shaft-side engagement groove 20 function as positioning means that facilitate the positioning of the mounting auxiliary member 7 relative to the rear shaft portion 2b (shaft 2). Furthermore, the lateral projection 63a and the shaft-side engagement groove 20 also function as guide means to prevent misalignment when the rear part 2b (shaft cylinder 2) is moved relative to the rear part 2b of the shaft cylinder and when it is moved in the direction toward the front of the rear part 2b of the shaft cylinder. In addition, the lateral projection 63a and the shaft-side engagement groove 20 also function as rotation restricting means to prevent relative rotation of the mounting auxiliary member 7 with respect to the rear part 2b (shaft cylinder 2) (relative rotation around the central axis α1). Furthermore, at this point, a portion of the lumpy portion 85 is inserted into the rear elongated hole portion 13 (see Figures 17(b) and 18(a)).

[0112] (Temporary installation process of exterior components) Next, as shown in Figure 18(a), the exterior member 8 is temporarily attached to the mounting support member 7. That is, the first engaging piece 113a and the second engaging piece 113b of the exterior member 8 are inserted into the first insertion space 100 and the second insertion space 101 of the mounting support member 7, respectively (the first insertion space 100 is not shown in Figure 18(a); see Figure 7(a)). As a result, as shown in Figure 18(b), the pressing plate portion 110 covers the block-shaped portion 85 (see Figure 18(a)) and the first raised portion 71 from above. Through the above steps, a work-in-progress of the writing instrument 1 (hereinafter also referred to as a writing instrument work-in-progress) is formed by combining (temporarily assembling) the rear part of the barrel 2b, the connecting body (pressing member 5, operating member 6), the mounting auxiliary member 7, and the exterior member 8.

[0113] (Pressing process) Next, as shown in Figure 18(a), a pressing process is performed on the writing instrument work-in-progress using an external jig to apply pressure from the rear towards the front. This results in the exterior member 8 being permanently attached to the mounting auxiliary member 7 (details will be described later). Then, the rear part 2b of the shaft cylinder, the connecting body (pressing member 5, operating member 6), the mounting auxiliary member 7, and the exterior member 8 are each adjusted so that their relative positions are appropriate to each other, and they move from a temporarily assembled state to an assembled state.

[0114] In this embodiment, as shown in Figure 19, a portion of the pressing plate portion 110 is positioned to coincide with the central axis α1 (the region through which the central axis α1 passes). More specifically, as shown in Figure 19(b), in a plan view of the writing instrument 1 from the rear, the pressing plate portion 110 extends from the outermost edge of the writing instrument 1 (which is also the edge of the contour, and the portion near the lower end in Figure 19(b)) toward the central axis α1 along the first direction. The tip of the pressing plate portion 110 in the extension direction (first direction) is positioned beyond the central axis α1 in the same direction. That is, the middle portion of the pressing plate portion 110 in the extension direction is positioned to coincide with the central axis α1, and the tip portion in the extension direction is located toward the tip in the first direction than the central axis α1.

[0115] With this configuration, as described above, by applying pressing force with an external jig, the pressing force is appropriately applied to the mounting auxiliary member 7 and the connecting body via the exterior member 8, and each is positioned in the correct location. In other words, with a single pressing operation using a single jig, the assembly of five components—the rear part of the barrel 2b, the pressing member 5, the operating member 6, the mounting auxiliary member 7, and the exterior member 8—can be performed, thus simplifying the manufacturing process of the writing instrument 1.

[0116] (Core component installation process) After the pressing process, as shown in Figure 1, the writing instrument 1 is assembled by inserting the rear portion of the core member 4 into the rear part 2b of the barrel, fitting the rear portion of the biasing member 3 onto the front portion of the core member 4, and attaching the front part 2a of the barrel to the rear part 2b of the barrel. When replacing the core member 4, the writing instrument 1 can be replaced by removing the front part 2a of the barrel, taking out the core member 4, and then attaching a new core member 4 using the same procedure.

[0117] In this embodiment, the writing instrument 1 has the rear portion of the core member 4 inserted into the pressing member 5 from the front, and the rear end portion of the core member 4 is in contact with the internal contact wall portion 42 of the pressing member 5 from the front. In addition, the writing instrument 1 has the front end portion of the biasing member 3 in contact with the shaft-side contact portion 17 of the front part 2a of the barrel from the rear, and the rear end portion in contact with the core-side contact wall portion 28 of the core member 4 from the front. As a result, the core member 4 is constantly biased backward by the biasing member 3.

[0118] In this embodiment, as shown in Figure 20, the writing instrument 1 has a pair of engaging parts, the engaging piece forming part 84 and the exterior side engaging part 113, which are engaged parts, and the first engaging piece part 113a and the second engaging piece part 113b are located on both sides of the engaging piece forming part 84 in the third direction.

[0119] As described above, the engagement piece forming portion 84 has an introduction guide portion 84a on its rear side. Therefore, when the writing instrument 1 engages the engagement piece forming portion 84 with the exterior engagement portion 113 (see Figure 18(a)), it is easy to introduce the rear side portion of the engagement piece forming portion 84 between the front ends of the first engagement piece portion 113a and the second engagement piece portion 113b (the lower ends in Figure 20).

[0120] Furthermore, the first restricting piece 95, the second restricting piece 96, and the first restricting piece 115, the second restricting piece 116 allow relative movement of the exterior member 8 with respect to the mounting auxiliary member 7 in the mounting direction, while restricting relative movement in the removal direction.

[0121] For example, if the exterior member 8 is moved forward and attached without moving the mounting support member 7 (see Figure 18(a), shown at the bottom of the figure), the exterior member 8 will move forward. As a result, the inclined surfaces of the two second restricting pieces 116 of the exterior member 8 will be in surface contact with the inclined surfaces of the two first restricting pieces 95 (detailed illustration omitted). In this case, as the exterior member 8 is moved forward, the contact position between the inclined surfaces changes, and the exterior member 8 moves forward, causing the two second restricting pieces 116 to move forward over the two first restricting pieces 95. Similarly, the two second restricting pieces 116 then move forward over the two second restricting pieces 96, and the two first restricting pieces 115 then move forward over the two first restricting pieces 95. As a result, the engaging piece forming part 84 and the exterior side engaging part 113 engage, and the exterior member 8 is attached to the mounting support member 7.

[0122] In contrast, as shown in Figure 20, when the engaging piece forming portion 84 and the exterior-side engaging portion 113 are engaged, if the exterior member 8 is moved relative to the mounting auxiliary member 7 in the attachment / detachment direction, the rear surfaces of the two second restricting pieces 116 come into contact with the front surfaces of the two second restricting pieces 96. As a result, the relative movement of the exterior member 8 in the removal direction relative to the mounting auxiliary member 7 (rearward movement with the mounting auxiliary member 7 fixed) is restricted (prevented). In other words, in this embodiment, the exterior member 8 is attached to the mounting auxiliary member 7 in a fixed state by the engagement of the engaging piece forming portion 84 and the exterior-side engaging portion 113. Note that the fixed state referred to here means that it cannot be removed unless at least a part of one or both of the separately formed mounting auxiliary member 7 and the exterior member 8 is deformed or destroyed.

[0123] As shown in Figure 20, the writing instrument 1 of this embodiment has a gap (first locking gap) formed between the rear surface of the first regulating piece 115 and the front surface of the first regulating piece 95, and the maximum length of this gap in the front-rear direction is set to a predetermined length L1. Note that the maximum length in the front-rear direction referred to here is the maximum value of the lengths of each part in the front-rear direction. In addition, the writing instrument 1 has a gap (second locking gap) formed between the rear surface of the second regulating piece 116 and the front surface of the second regulating piece 96, and the maximum length of this gap in the front-rear direction is set to a predetermined length L2.

[0124] Furthermore, the writing instrument 1 has a predetermined length L1 that is longer than the predetermined length L2, and more specifically, the predetermined length L1 is about twice as long as the predetermined length L2. Note that "about twice" here includes not only a perfect double, but also an error margin of a few percent. Furthermore, in this embodiment, when the exterior member 8 is attached to the mounting auxiliary member 7, the front portions (lower portions in Figure 20) of the first engaging piece 113a and the second engaging piece 113b are in contact with the two contact surfaces 98 from the rear.

[0125] With this configuration, the writing instrument 1 of this embodiment can be securely attached to the exterior member 8 by the mounting auxiliary member 7, and rattling of the exterior member 8 in the front-to-back direction can be reduced. In other words, as described above, when the exterior member 8 is attached, both the second restricting piece 116 and the first restricting piece 115 come into contact with the first restricting piece 95 in that order. For this reason, the first restricting piece 95 is more likely to deform unintentionally when the exterior member 8 is attached than the second restricting piece 96, which only comes into contact with the second restricting piece 116. For this reason, as described above, the predetermined length L1 is intentionally made longer, so that even if the protruding end of the first restricting piece 95 is crushed and deformed so as to face forward, the problem of the exterior member 8 being unable to be attached due to this deformation is prevented. On the other hand, by shortening the predetermined length L2, when the exterior member 8 attempts to move relative to the mounting support member 7 in the removal direction, the distance of movement is reduced, thus preventing the exterior member 8 from rattling excessively in the front-to-back direction. Furthermore, in this embodiment, the writing instrument 1 is structured such that when the exterior member 8 is attached to the mounting auxiliary member 7, the exterior member 8 does not move any further relative to the mounting auxiliary member 7 in the mounting direction. That is, if the first engaging piece 113a and the second engaging piece 113b move relative to the mounting auxiliary member 7 and attempt to move in the direction toward the front of the mounting auxiliary member 7, this movement is prevented by contacting the two contact surfaces 98 from behind.

[0126] While not particularly limited, the predetermined length L2 is preferably 0.1 mm or less. In addition to this configuration, the writing instrument 1 may also be configured such that a gap is formed between the rear surface of the first restricting piece 115 and the front surface of the first restricting piece 95, while the rear surface of the second restricting piece 116 and the front surface of the second restricting piece 96 are in contact, so that no gap is formed between them.

[0127] Furthermore, in this embodiment, the outer surfaces of each of the two locking wall portions 97 of the writing instrument 1 are in contact with the first engaging piece portion 113a and the second engaging piece portion 113b, respectively, from the inside in a third direction. More specifically, the outer surfaces of the locking wall portions 97 are in contact from the inside with the protruding ends of the first engaging piece portion 113a and the second engaging piece portion 113b, which are located in front of (downward in Figure 20) the second restricting piece portion 116. As a result, the writing instrument 1 of this embodiment can be attached to the mounting auxiliary member 7 so that the front portion of the exterior mounting portion 107 does not rattle in the third direction. As a result, the exterior member 8 can prevent lateral movement of the clip, that is, rattle caused by the portion around the front end of the clip portion 108 (around the front wall portion 125, see Figure 12, etc.) swinging like a pendulum in the third direction.

[0128] Here, the writing instrument 1 is capable of switching between a retracted state in which the front end portion of the pen tip forming part 25 is located inside the barrel 2 (see Figure 1) and a protruding state in which the front end portion of the pen tip forming part 25 protrudes to the outside from the front opening 11 (not shown). In other words, as described above, the writing instrument 1 is a rear-knock type retractable writing instrument, and the retracted state and the protruding state are switched by pressing at least one of the mounting auxiliary member 7 and the exterior member 8 forward.

[0129] In detail, when the writing instrument 1 is in the retracted state, a knock operation is performed to press at least one of the mounting auxiliary member 7 and the exterior member 8 forward, causing the pressing member 5 and the operating member 6 to move forward. As the pressing member 5 and the operating member 6 move forward, the engagement position of the pressing-side cam portion 33 and the operating-side cam portion 52 (see Figure 17(a)) changes, and the pressing member 5 rotates relative to the operating member 6. Then, the engagement position of the pressing-side engagement portion 32 of the pressing member 5 and the barrel-side engagement portion 19 of the barrel 2 (see Figure 4) changes, and the pressing member 5 is positioned further forward inside the barrel 2. As a result, the lead member 4 is pressed forward by the pressing member 5, the front end portion of the pen tip forming portion 25 protrudes outside the barrel 2, and the writing instrument 1 transitions to the protruding state.

[0130] In contrast, when the writing instrument 1 is in the protruding state, a knock operation is performed to press at least one of the mounting auxiliary member 7 and the exterior member 8 forward, causing the pressing member 5 and the operating member 6 to move slightly forward. As a result of this movement, the engagement position of the pressing-side cam portion 33 and the operating-side cam portion 52 (see Figure 17(a)) changes, causing the pressing member 5 to rotate relative to the operating member 6, and changing the engagement position of the pressing-side engagement portion 32 of the pressing member 5 and the barrel-side engagement portion 19 of the barrel 2 (see Figure 4). When the pressing force by the user is released in this state, the biasing force of the biasing member 3 pushes the lead member 4 backward, the lead member 4 pushes the pressing member 5 backward, and the pressing member 5 further pushes the operating member 6 backward. In other words, the core member 4, the pressing member 5, and the operating member 6 each move backward, and as the operating member 6 moves backward, the mounting auxiliary member 7 attached to the operating member 6 and the exterior member 8 attached to the mounting auxiliary member 7 also move backward. As a result, the front end portion of the pen tip forming part 25 retracts into the barrel 2, and the writing instrument 1 moves into the retracted state.

[0131] As shown in Figure 21(a), the writing instrument 1 of this embodiment has the aforementioned pressing plate portion 110, first side wall portion 111, and second side wall portion 112, which form a part of the portion of the writing instrument 1 that receives the knocking operation, from the side to the rear end. In other words, the pressing plate portion 110, first side wall portion 111, and second side wall portion 112 are arranged in the portion that is easily subjected to the knocking operation.

[0132] As described above, the pressing plate portion 110 is elastically deformable, and its protruding end portion is swingable (see Figure 14). Furthermore, in a natural state without any external force such as pressing force applied, the writing instrument 1 has a first void portion 136 (void portion) between the inner surface (front surface) of the rear plate forming portion 110c and the rear surface of the first raised portion 71 (first raised rear wall portion 71a), as shown in Figure 21(b).

[0133] Furthermore, the writing instrument 1 has a second void 137 between the inner surface of the first side wall portion 111 (protruding piece portion 111b) and the outer surface of the first raised side wall portion 71b located on one end side in the third direction. In addition, the writing instrument 1 has a third void 138 between the inner surface of the second side wall portion 112 (side wall body portion 112a) and the outer surface of the first raised side wall portion 71b located on the other end side in the third direction. Furthermore, the writing instrument 1 has a fourth void 139 between the front end portion (lower end portion in Figure 21(b)) of the protruding piece 111b of the first side wall portion 111 and the front end portion (groove bottom portion) of the first groove portion 73. In addition, the writing instrument 1 has a fifth void 140 between the front end portion of the protruding piece 112b of the second side wall portion 112 and the front end portion (groove bottom portion) of the second groove portion 74. In this embodiment, the first void portion 136 to the fifth void portion 140 form a series of spaces.

[0134] According to this embodiment, when force is applied to the rear plate forming portion 110c, such as by being knocked from diagonally behind, the tip side of the rear plate forming portion 110c moves downward and comes into contact with the rear side surface of the first raised portion 71, causing both the mounting auxiliary member 7 and the exterior member 8 to move forward. As a result, the writing instrument 1 of this embodiment can reduce the load caused by the knocking operation.

[0135] Furthermore, in this embodiment, the rear plate forming portion 110c swings between the protruding piece 111b of the first side wall portion 111 and the protruding piece 112b of the second side wall portion 112. As a result, even if force is applied to the rear plate forming portion 110c from the outside and above the first side wall portion 111, the protruding pieces 111b and 112b function as guides, and the rear plate forming portion 110c swings in the intended direction and in the intended posture. As a result, in the writing instrument 1 of this embodiment, the rear plate forming portion 110c appropriately contacts the rear surface of the first raised portion 71, and the load caused by the knocking operation can be reduced more reliably. Furthermore, in this embodiment, even if an unintended strong force is applied to the rear plate forming portion 110c from the side, such as by dropping the writing instrument 1, the first side wall portion 111 and the second side wall portion 112 function as protective members for the rear plate forming portion 110c. As a result, the writing instrument 1 can prevent unintended deformation of the rear plate forming portion 110c.

[0136] Furthermore, as described above, the writing instrument 1 has a configuration that includes a fourth void 139 and a fifth void 140 in addition to the first void 136. As a result, when force is applied to the area spanning the rear plate forming portion 110c and the two protruding pieces 111b and 112b, such as when knocked from the rear, the writing instrument 1 can distribute the load evenly (or approximately evenly) to the rear plate forming portion 110c and the two protruding pieces 111b and 112b. As a result, the writing instrument 1 of this embodiment can prevent deterioration of the exterior member 8 due to prolonged use. Furthermore, it is preferable that the size of the fourth void 139 and the fifth void 140 (their respective maximum lengths in the front-to-back direction) be greater than or equal to the size of the first void 136 (their maximum length in the front-to-back direction). In this embodiment, the writing instrument 1 has the sizes of the fourth void 139 and the fifth void 140 larger than the size of the first void 136. With this configuration, when a strong force is suddenly applied to the area spanning the rear plate forming portion 110c and the two protruding pieces 111b and 112b, unintended deformation of the pressing plate portion 110 can be prevented (suppressed). Here, the "size of the first void 136" is the maximum length in the front-to-back direction of the portion between the inner surface of the rear plate forming portion 110c and the rear surface of the first raised rear wall portion 71a, and the rear surface of the first raised rear wall portion 71a is the rear end surface excluding the portion in which the rear recess 77 is formed.

[0137] It should be added that, as described above, in this embodiment, the first engaging piece 113a and the second engaging piece 113b of the writing instrument 1 are in contact with the two contact surfaces 98 from the rear (see Figure 20). As a result, if force is applied to the area spanning the rear plate forming portion 110c and the two protruding pieces 111b and 112b, the entire exterior member 8 moves forward relative to the mounting auxiliary member 7, and the state in which the fourth gap portion 139 and the fifth gap portion 140 are formed is maintained.

[0138] Furthermore, in this embodiment, as shown in Figure 21(a), the writing instrument 1 has a block-shaped portion 85 positioned close to the inside of the portion enclosed by the side plate forming portion 110a, the side wall main body portion 111a, and the side wall main body portion 112a. Therefore, even if an unintended force is applied to the continuous portion of these side plate forming portion 110a, the side wall main body portion 111a, and the side wall main body portion 112a, it is possible to prevent the exterior member 8 (exterior side mounting portion 107) from undergoing unintended large deformation.

[0139] Furthermore, in this embodiment, as described above, as shown in Figure 16, the first engaging piece 113a and the second engaging piece 113b protrude diagonally (in a direction toward the inside in the third direction and toward the tip side in the second direction). Therefore, as shown in Figure 18(a), when the exterior member 8 is attached to the mounting auxiliary member 7 of the writing instrument 1 of this embodiment, the first engaging piece 113a and the second engaging piece 113b come into contact with the block-shaped portion 85 from the inside (from the base end side in the second direction) (detailed illustration is omitted). As a result, the writing instrument 1 can prevent rattling of the exterior member 8 in the first and second directions.

[0140] As shown in Figure 21(a), the writing instrument 1 of this embodiment has its first-direction end of the exterior member 8, that is, the first-direction ends of the rear plate forming portion 110c and the two protruding pieces 111b and 112b, facing the step-forming surface portion 79 and positioned adjacent to the step-forming surface portion 79. More specifically, the first-direction end of the exterior member 8 is in contact with the step-forming surface portion 79, or is separated from it with a minute gap between them. Furthermore, the rear surface (upper surface in Figure 21) of the rear plate forming portion 110c and the rear surface of the second raised rear wall portion 72a are continuous in the first direction, forming a series of surfaces that constitute a curved surface shape. That is, both the rear surface of the rear plate forming portion 110c and the rear surface of the second raised rear wall portion 72a are curved with a similar (or approximately similar) curvature so as to be convex towards the rear, and the front-to-back direction (up-to-down direction in Figure 21) of each part in the third direction is the same (or approximately the same). Furthermore, the outer surfaces of the two protruding pieces 111b and 112b, and the outer surfaces of the two second raised side wall portions 72b and 72b located at both ends in the third direction, are located on the same plane (or substantially on the same plane), forming a series of surfaces. As a result, the writing instrument 1 of this embodiment can have a beautiful, unified appearance at the rear. In addition, as a result, it is possible to prevent (suppress) the problem of the user feeling discomfort in their fingertips when knocking on the area of ​​the rear end portion that spans the mounting auxiliary member 7 and the exterior member 8.

[0141] In the embodiment described above, the writing instrument 1 is a rear-click type ballpoint pen, but the present invention is not limited thereto. The retractable writing instrument of the present invention can be any writing instrument, for example, a mechanical pencil that extends a graphite lead. In this case, the pen tip portion is the tip portion of the graphite lead. In the embodiment described above, an example was shown in which the exterior member 8 is indirectly attached to the operating member 6 via the mounting auxiliary member 7. However, the member to which the exterior member 8 is attached may be the operating member 6 instead of the mounting auxiliary member 7. That is, the retractable writing instrument may be provided with the rear wall forming portion 64 and the engaging piece forming portion 84 on the operating member, and the exterior member 8 may be directly attached to the operating member. In this case, the operating member is not particularly limited, but it is preferable that it be made of resin, and from the viewpoint of enabling smooth retraction and extension, it is preferable that it be made of POM (polyacetal resin) as the main raw material.

[0142] In the embodiments described above, the components can be freely substituted or added between each embodiment, as long as they fall within the technical scope of the present invention. [Explanation of symbols]

[0143] 1 Writing instrument 1 (removable writing instrument) 2 shaft cylinder 6 Operating Member 7. Mounting support members (intermediate members, members to be mounted) 8. Exterior components 25. Pen tip forming section (pen tip section) 60 Auxiliary member main body (target member main body) 63 Side wall forming part (side wall part) 71 1st protuberance 71a First raised rear wall (rear wall) 72 Second bulge 73 First trench section 74 Second groove 84 Engagement piece forming portion (target side engagement piece) 107 Exterior side mounting part 108 Clip section 110 Pressing plate section 113a First engaging piece (engaging piece) 113b Second engagement piece (engagement piece) 136 1st cavity (void)

Claims

1. A retractable writing instrument comprising a barrel, a pen tip, and an operating member, wherein at least a portion of the pen tip protrudes outside the barrel when the operating member moves relative to the barrel, The exterior member has the aforementioned operating member or an intermediate member attached to the aforementioned operating member as the mounting target member, The exterior member comprises a pressing plate portion, The mounting target member has a side wall portion and a rear wall portion located behind the side wall portion. The pressing plate portion extends from the side of the side wall portion to the rear of the rear wall portion, and the tip portion in the extending direction is a free end and is swingable forward. A retractable writing instrument in which pressing the pressing plate portion forward causes the rear wall portion to be pressed forward by the pressing plate portion.

2. The retractable writing instrument according to claim 1, wherein in a natural state where no external force is applied, there is a gap between the pressing plate portion and the rear wall portion.

3. The retractable writing instrument according to claim 1 or 2, wherein the pressing plate portion extends in a direction toward the central axis from the side in a plan view taken from the rear in the longitudinal direction of the central axis, the middle portion of the extension is positioned to coincide with the central axis, and the tip portion of the extension is positioned to cross the central axis.

4. The exterior member has a first side wall portion and a second side wall portion, The retractable writing instrument according to claim 1 or 2, wherein the pressing plate portion is disposed between the first side wall portion and the second side wall portion, and by pressing the pressing plate portion forward, the tip portion of the pressing plate portion moves below the rear ends of the first side wall portion and the second side wall portion.

5. The mounting member has a first raised portion, a second raised portion, a first groove, and a second groove. The rear portion of the first raised portion forms the rear wall portion, The first raised portion and the second raised portion have a step-forming surface portion at the boundary, and the first raised portion and the second raised portion are continuous such that their respective rear surfaces and respective side surfaces have a step through the step-forming surface portion. In a plan view taken from the rear along the longitudinal direction of the central axis, the first groove and the second groove are located on either side of the first raised portion. The front portion of the first side wall and the front portion of the second side wall are arranged inside the first groove and the second groove, respectively. In a plan view taken from the rear along the longitudinal direction of the central axis, when the direction from the first raised portion to the second raised portion is defined as the first direction, the pressing plate portion, the first side wall portion, and the tip side surface of the second side wall portion in the first direction in their natural state face the step-forming surface portion, as described in claim 4.

6. The mounting target member has a target member body and a target-side engaging piece that protrudes laterally from the target member body. The exterior member has an exterior-side engaging portion, The exterior-side engaging portion includes two engaging piece portions that engage with the target-side engaging piece, At least a portion of the target-side engaging piece is positioned between the two engaging piece portions, and the exterior member is attached to the mounting target member while engaged with the two engaging piece portions. The retractable writing instrument according to claim 1 or 2, wherein the target-side engaging piece and the two engaging piece portions allow relative movement of the mounting target member and the exterior member in the mounting direction, and restricts relative movement of the mounting target member and the exterior member in the removal direction, and the exterior member is fixedly attached to the mounting target member.

7. The retractable writing instrument according to claim 6, wherein the front portion of the target-side engaging piece has a portion at one end in a predetermined direction that contacts a part of one of the engaging pieces, and the portion at the other end located on the opposite side in the predetermined direction that contacts a part of the other engaging piece.

8. The exterior member has an exterior mounting portion and a clip portion. The retractable writing instrument according to claim 1 or 2, wherein the clip portion extends forward from the exterior mounting portion.

9. The retractable writing instrument according to claim 1 or 2, wherein the exterior member is made of metal and the mounting member is made of resin.

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