Writing instrument with malfunction prevention function

Abstract

To provide a knock-type writing instrument including a cylindrical main body extending in the front-to-rear direction, with a taper at the tip and a knock portion at the rear end, and a clip portion disposed at the rear end of the main body for clamping the main body to a fastening material, and by applying a forward force from the rear end toward the tip to the knock portion to activate the knock, the writing tip protrudes in the forward direction from the opening of the taper and is held in a writing position to be ready for writing, in which when the clip portion is clamped to the fastening material, the writing tip is prevented from protruding from the opening of the taper due to an inadvertent application of a forward force toward the knock portion.SOLUTION: Provided is a writing instrument with a malfunction prevention function in which a knock guard portion is provided at the rear end of a main body to prevent a forward force from being inadvertently applied to the knock portion when the forward force is about to be applied inadvertently to the knock portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention relates to a knock-type writing instrument equipped with a clip, and in particular to a writing instrument with an anti-malfunction function that prevents the writing tip from protruding from the tip of the barrel even if force to activate the knock part is inadvertently applied when the clip is clipped to a pocket, notebook, or other fastening. [Background technology]

[0002] In a knock-type writing instrument equipped with a clip, if the knock part is inadvertently pressed while the clip is attached to a pocket, notebook, or other fastening, the writing tip may protrude from the tip of the barrel, causing various problems. This is explained below using an example of a conventional knock-type writing instrument equipped with a clip, as shown in Figure 1.

[0003] The cylindrical body 2 that constitutes the writing instrument 1 extends in the longitudinal direction, which is the left-right direction in Figures 1(a) and (b), and has a taper 3 at the tip (left end of Figure 1(a)) and a clip portion 6 and a knock portion 4 at the rear end (right end of Figure 1(a)).

[0004] Hereinafter, in this specification, the tip side of the cylindrical main body 2 constituting the writing instrument 1 will be referred to as the front side, the rear side as the rear side, the direction from the rear side of the main body 2 toward the tip side as the forward direction, and the direction from the tip side of the main body 2 toward the rear side as the backward direction. Normally, as shown in Figure 1(a), the writing tip 5 is recessed within the opening of the taper 3 and stored within the main body 2. When the knock is activated, that is, when a forward force is applied to the rear end surface 4a of the knock portion 4 as shown by arrow 10 in Figure 1(b), the writing tip 5 protrudes from the opening of the taper 3 and is held in the writing position, ready for writing (Figure 1(b)).

[0005] FIG. 5 is a diagram for explaining an example of malfunction in the conventional general writing instrument 1 shown in FIG. 1. FIG. 5(a) is a front view with a part omitted for explaining a state in which the writing instrument 1 is attached to the pocket 40 of clothes.

[0006] When the writing instrument 1 is attached to the pocket 40, due to the structure of the writing instrument 1, the portion from the rear end of the clip 6 to the rear end of the knock part 4 shown by L1 in FIG. 1(a) will protrude from the edge of the pocket 40 (FIG. 5(a)). FIG. 5(c) is a perspective view for explaining a state in which the conventional general writing instrument 1 shown in FIG. 1 is attached to a notebook 41 or the like. Also in this case, due to the structure of the writing instrument 1, the portion from the rear end of the clip 6 to the rear end of the knock part 4 will protrude from the edge of the notebook 41.

[0007] As described above, since the non-small (not short) portion shown by L1 in FIG. 1(a) protrudes from the edge of the pocket 40 or the edge of the notebook 41, when carrying or working with the writing instrument 1 attached to the pocket 40, notebook 41, file, etc., the knock may be accidentally activated.

[0008] If the knock is accidentally activated, since the writing tip 5 protrudes from the opening of the taper 3 and is held in the writing position, the inside of the pocket 40 may be soiled with ink or the like. For example, if the knock is accidentally activated while the writing instrument 1 is attached to the pocket 40 (FIG. 5(a)), the inside of the pocket 40 may be soiled with the ink 50 of a ballpoint pen or the like as shown in FIG. 5(b). Also, if the knock is accidentally activated while the writing instrument 1 is attached to the notebook 41 (FIG. 5(c)), the notebook 41 may be soiled with the ink 51 of a ballpoint pen or the like as shown in FIG. 5(c).

[0009] In a knock-type writing instrument, as described above, the knock part 4 is intentionally knocked as shown by the arrow 10 in FIG. 1(b) to apply a force in the forward direction to activate the knock, and the writing tip 5 is protruded from the opening of the taper 3 and held in the writing position to enable writing.

[0010] On the other hand, when not intended, the knock part 4 is pushed in the direction indicated by the arrow 10 in Fig. 1(b), that is, a force in the forward direction is inadvertently (e.g., carelessly) applied to the knock part, causing the knock to operate, and the writing tip 5 protrudes from the opening of the taper 3 and is held in the writing position, resulting in a state where writing can be performed.

[0011] In the present specification, the situation where such a force in the forward direction is inadvertently, that is, without intention, applied to the knock part, causing the writing tip 5 to protrude from the opening of the taper 3 and be held in the writing position, resulting in a state where writing can be performed, is hereinafter referred to as malfunction in a knock-type writing instrument.

[0012] If a malfunction occurs, as described above, problems such as the pocket 40 or notebook 41 in which the writing instrument 1 is mounted being soiled will occur.

[0013] To prevent such problems from occurring, when a knock-type writing instrument equipped with a clip is clamped to a fastening object such as a pocket or a notebook with the clip, a writing instrument with a malfunction prevention function has been proposed conventionally, which prevents the writing tip from protruding from the tip of the barrel even if the knock part is inadvertently pushed.

[0014] For example, Patent Document 1 discloses a knock-type writing instrument equipped with a clip, which can prevent the clothing from being soiled with ink when the writing instrument is inserted into a pocket of clothing such as a shirt and carried, and accidentally pressing the knock part while in the inserted state to cause the refill to protrude from the tip of the barrel shaft.

[0015] The applicant of the present application has also proposed a knock-type writing instrument with a malfunction prevention function in a knock-type writing instrument equipped with a clip, which can prevent the writing body from advancing even if the knock part is inadvertently pushed while the writing instrument is fastened to a pocket or the like with the clip, regardless of the strength of the pocket fabric or the thickness of the notebook paper (Patent Document 2).

Prior Art Documents

Patent Documents

[0016] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-168443 [Patent Document 2] Japanese Patent No. 6881748 [Summary of the Invention] [Problems to be Solved by the Invention]

[0017] The present invention provides a cylindrical body having a taper at the tip and a knock portion at the rear end, extending in the longitudinal direction which is the front-rear direction, and a clip portion disposed on the rear end side of the body for sandwiching the body between fastening objects. By applying a forward force in the forward direction from the rear end to the knock portion to operate the knock, the writing tip protrudes from the opening of the taper in the forward direction and is held in the writing position so that writing can be performed. In a knock-type writing instrument, when the clip portion sandwiches a fastening object, it is an object of the present invention to propose a writing instrument with a malfunction prevention function that can prevent a forward force from being inadvertently applied toward the knock portion and the writing tip from protruding from the opening of the taper. [Means for Solving the Problems]

[0018] The present invention for solving the above-described problems can be exemplified as follows. [1] A knock-type writing instrument having a cylindrical body having a taper at the tip and a knock portion at the rear end, extending in the longitudinal direction which is the front-rear direction, and a clip portion disposed on the rear end side of the body for sandwiching the body between fastening objects. By applying a forward force in the forward direction from the rear end to the knock portion to operate the knock, the writing tip protrudes from the opening of the taper in the forward direction and is held in the writing position so that writing can be performed. When a force in the forward direction is inadvertently applied to the knocking part, a knock guard part is provided at the rear end of the main body to prevent the inadvertent force in the forward direction from being applied to the knocking part. Writing instrument with malfunction prevention function.

[0019] [2] When viewing the writing instrument with the malfunction prevention function in the forward direction from the rear side of the writing instrument with the malfunction prevention function, the knock guard part covers at least a part of the rear end surface of the knocking part, which is the rear end surface of the knocking part, and is fixedly arranged with respect to the rear end of the main body. The writing instrument with the malfunction prevention function according to [1] is provided with a guard part on the rear side of the rear end surface of the knocking part.

[0020] [3] The knock guard part includes a guard support part extending from the rear end of the main body in the backward direction, which is the direction from the front end to the rear end. The guard part is supported by the guard support part at the rear end of the guard support part, which is the rear end of the guard support part. The writing instrument with the malfunction prevention function according to [2].

[0021] [4] The guard support part is formed integrally with the main body or is formed separately from the main body. The writing instrument with the malfunction prevention function according to [3].

[0022] [5] The main body is provided with a tail plug at the rear end. The guard support part is formed integrally with the tail plug or is formed separately from the tail plug. The writing instrument with the malfunction prevention function according to [3].

[0023] [6] When viewing the writing instrument with the malfunction prevention function in the forward direction from the rear side of the writing instrument with the malfunction prevention function, the guard part covers a part of the periphery of the rear end surface of the knocking part and is arc-shaped. The writing instrument with the malfunction prevention function according to [2] or [3].

[0024] [7] The guard part is composed of a plate-like body parallel to the rear end face of the knock part, and is a writing instrument with an anti-malfunction function of [2] or [3].

[0025] [8] The clip part is a writing instrument with an anti-malfunction function of any one of [3] to [7], which is supported by the guard support part.

[0026] [9] A writing instrument with an anti-malfunction function of [8], in which the position of the rear end of the clip part in the front-rear direction, which is the rear end of the clip part, is substantially the same as the position of the guard part in the front-rear direction.

Effect of the Invention

[0027] According to the present invention, in a knock-type writing instrument having a cylindrical body that extends in the front-rear direction and is provided with a taper at the tip and a knock part at the rear end, and a clip part that is disposed on the rear end side of the body and sandwiches the body between fasteners, by applying a forward force in the forward direction, which is the direction from the rear end to the tip, to the knock part to operate the knock, the writing tip protrudes from the opening of the taper in the forward direction and is held at the writing position so that writing can be performed. When the clip part sandwiches the fastener, it is possible to provide a writing instrument with an anti-malfunction function that can prevent the writing tip from protruding from the opening of the taper due to an inadvertent forward force being applied toward the knock part.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0029] An example of a writing instrument 11 with an anti-malfunction function according to an embodiment of the present invention will be described with reference to FIGS. 2 and 3. Hereinafter, in this specification, the writing instrument 11 with an anti-malfunction function may sometimes be simply referred to as "writing instrument 11".

[0030] The writing instrument 11 of this embodiment includes a main body 12 and a clip portion 16 (FIG. 2). The main body 12 has a taper 13 at the tip (the left end in FIG. 2(b)) and a knock portion 14 at the rear end (the right end in FIG. 2(b)), and is cylindrical and extends in the front-rear direction. The clip portion 16 is provided on the rear end side of the main body 12, and functions to sandwich the main body 12 between fastening objects such as a pocket or a notebook, similar to the clip portion 6 in the conventional writing instrument 1 described with reference to FIGS. 1 and 5.

[0031] Similar to the conventional writing instrument 1 described with reference to FIG. 1, the writing instrument 11 of this embodiment is a knock-type writing instrument that can be used for writing by applying a forward force in the forward direction from the rear end to the tip to the knock portion 14 to operate the knock, so that as shown in FIG. 3(b), the writing tip protrudes from the opening of the taper 13 in the forward direction and is held in the writing position.

[0032] When an unintended forward force is about to be applied to the knock part 14 of the writing instrument 11 of this embodiment, that is, without intention, the knock guard part 17 that prevents the unintended forward force from being applied to the knock part 14 is provided at the rear end of the main body 12, which is a characteristic feature.

[0033] Except for this point, the writing instrument of the present invention adopts the same configuration, structure, and mechanism as the conventionally known cylindrical main body 2 that is provided with a taper 3 at the front end and a knock part 4 at the rear end and extends in the front-rear direction, and a clip part 6 that is provided on the rear end side of the main body 2 and sandwiches the main body 2 between fastening objects. By applying a forward force in the forward direction, which is the direction from the rear end to the front end indicated by the arrow 10 in FIG. 1(b), to the knock part 4 to operate the knock, the writing tip 5 protrudes from the opening of the taper 3 in the forward direction and is held at the writing position to enable writing.

[0034] For example, the writing instrument 11 of this embodiment can be applied to a liquid marker, a mechanical pencil, or other appropriate writing bodies. In FIGS. 2 and 3, a writing instrument having a ballpoint pen refill 19 as a writing body is described as an example.

[0035] The cylindrical main body 12 that constitutes the writing instrument 11 extends in the longitudinal direction, which is the left-right direction in FIGS. 2(b), (c), 3(a), and (b). It has a taper 13 at the front end (the left end in FIG. 2(b)), and a knock part 14 is provided at the rear end (the right end in FIG. 2(b)) of the main body 12.

[0036] In the illustrated embodiment, the main body 12 is provided with a taper mounting screw part 12a on the inner peripheral wall of its front end (FIG. 8(e)), the taper 13 is provided with a screw part 13a (FIG. 7(a)), and a structure in which the two are mounted between each other is adopted.

[0037] As shown in FIGS. 3, the refill 19 is retractable within the main body 12, that is, it is housed so as to be movable in the forward direction and the backward direction.

[0038] The refill 19 is biased in the backward direction by a spring 20 (Fig. 3).

[0039] As a mechanism for moving and feeding out a writing body such as the refill 19 in the forward direction by knocking the knock portion 14 as indicated by an arrow 10 in Fig. 3(b), various conventionally known mechanisms can be adopted. These are well-known mechanisms, and detailed illustration and description thereof are omitted.

[0040] In the present embodiment, an example in the case where a rotary cam type feeding mechanism is adopted is schematically illustrated. The cylindrical main body 12 is provided with a plurality of main body cam portions 12b at predetermined intervals in the circumferential direction on the inner peripheral wall on the rear end side, as illustrated in Fig. 8(e). The cylindrical knock portion 14 fitted inside the rear end of the main body 12 is provided with a plurality of positioning convex portions 14a at predetermined intervals in the circumferential direction on the outer peripheral wall on the front end side, and a cam portion 14b at the tip of the cylindrical portion, as illustrated in Fig. 9. Further, the cylindrical rotor 21 fitted inside the knock portion 14 is provided with a plurality of cam portions 21a at predetermined intervals in the circumferential direction on the outer peripheral wall on the front end side, and a refill receiving portion 21b formed to project radially inward at the rear end, as illustrated in Fig. 10.

[0041] By knocking the knock portion 14 as indicated by an arrow 10 in Fig. 3(b), the refill 19 moves forward against the biasing force of the spring 20, and the writing tip 15 provided at the tip of the refill 19 projects from the opening of the taper 13 and is held at the writing position (Fig. 3(b)). When the refill 19 moves backward from the writing position illustrated in Fig. 3(b), that is, the forward position, by the biasing force of the spring 20 and returns to the backward position illustrated in Fig. 3(a), the writing tip 15 is immersed in the opening of the taper 13 and is housed inside the main body 12 (Figs. 2 and 3(a)).

[0042] Hereinafter, the description will focus on the configuration and structure in which a knock guard 17 portion for preventing an unintended forward force from being applied to the knock portion 14, that is, when an unintended forward force is about to be applied to the knock portion 14 of the writing instrument 11 of the present embodiment, is provided at the rear end of the main body 12.

[0043] The knock guard portion 17 includes guard portions 18a and 18c (Figs. 2, 3, 11, and 12). The guard portions 18a and 18c are disposed in a position-fixed manner with respect to the rear end of the main body 12 on the rear side of the rear end surface 14a of the knock portion (Figs. 2, 3, 11, and 12). Further, the guard portions 18a and 18c are structured to cover at least a part of the knock portion rear end surface 14a, which is the rear end surface of the knock portion 14, when the writing instrument 11 is viewed in the forward direction from the rear side of the writing instrument 11 (Figs. 2(d) and 12(c)).

[0044] In the form shown in Figs. 2 and 3, the guard portion 18a is structured to cover about half of the circular knock portion rear end surface 14a when the writing instrument 11 is viewed in the forward direction from the rear side of the writing instrument 11 (Fig. 2(d)).

[0045] In this case, as shown in Figs. 3(a), (b), and 11(b), the guard portion 18a can be a plate-like body parallel to the knock portion rear end surface 14a.

[0046] In the form shown in Fig. 12, the guard portion 18c has an arc-shaped structure that covers a part of the periphery of the circular knock portion rear end surface 14a when the writing instrument 11b is viewed in the forward direction from the rear side of the writing instrument 11b (Fig. 12(c)).

[0047] In any structure, when an unintended forward force is about to be applied to the knock portion 14, the guard portions 18a and 18c of the knock guard portion 17 prevent the above-described force from being applied to the knock portion 14.

[0048] This will be described with reference to Fig. 4 in relation to the embodiments of Figs. 2 and 3. When attempting to apply a force in the forward direction indicated by arrow 10 to the knock portion 14 to activate the knock, if a human finger 30 comes into contact with the guard portion 18a of the knock guard portion 17 disposed on the rear side of the rear end face 14a of the knock portion, since the guard portion 18a is disposed in a position-fixed manner with respect to the rear end of the main body 12, it is not possible to apply a force in the forward direction indicated by arrow 10 to the rear end face 14a of the knock portion with the finger 30 (Fig. 4(a)).

[0049] Therefore, when an unintended forward force is about to be applied to the knock portion 14, the guard portion 18a of the knock guard portion 17 prevents the above-described force from being applied to the knock portion 14.

[0050] Thus, when the writing instrument 11 of this embodiment is attached to a pocket 40 or a notebook 41 as shown in Fig. 6, it is possible to prevent malfunctions from occurring and problems from arising as in the case of the conventional writing instrument 1 described with reference to Fig. 4.

[0051] On the other hand, when attempting to apply a force in the forward direction indicated by arrow 10 to the knock portion 14 to activate the knock, if the finger 30 is used to apply a force in the forward direction indicated by arrow 10 to the rear end face 14a of the knock portion while avoiding the guard portion 18a so that the human finger 30 does not come into contact with the guard portion 18a of the knock guard portion 17 (Fig. 4(b)), similar to the case of the conventional writing instrument 1 described with reference to Fig. 1, the writing tip 15 protrudes in the forward direction from the opening of the taper 13 and is held in the writing position, enabling writing (Fig. 4(c)).

[0052] This situation is the same in the case of the writing instrument 11a shown in Fig. 11 and the writing instrument 11b shown in Fig. 12, where the guard portion 18c has an arc-shaped structure that covers a part of the periphery of the rear end face 14a of the knock portion, which is circular when viewing the writing instrument 11b in the forward direction from the rear side.

[0053] As shown in Fig. 12, the writing instrument 11b is different from the writing instrument 11 shown in Figs. 2 and 3 only in that the shape of the guard part 18a is flat plate-shaped and covers about half of the rear end surface 14a of the circular knock part when the writing instrument 11 is viewed in the forward direction from the rear side of the writing instrument 11, while the guard part 18c has an arc-shaped structure that covers a part of the periphery of the rear end surface 14a of the circular knock part when the writing instrument 11b is viewed in the forward direction from the rear side of the writing instrument 11b. Therefore, regarding the writing instrument 11b shown in Fig. 12, the description of parts other than the shape and structure of the guard part 18c is omitted.

[0054] In the forms shown in Figs. 2 and 3, the guard part 18a has a structure that covers about half of the rear end surface 14a of the circular knock part when the writing instrument 11 is viewed in the forward direction from the rear side of the writing instrument 11. As described above, when an inadvertent forward force is about to be applied to the knock part 14, the guard part 18a prevents such an inadvertent force from being applied to the knock part 14 in the forward direction. Also, when trying to apply a forward force indicated by the arrow 10 to the knock part 14 to operate the knock, in order to prevent the human finger 30 from contacting the guard part 18a, the finger 30 avoids the guard part 18a and applies a forward force indicated by the arrow 10 to the rear end surface 14a of the knock part (Fig. 4(b)).

[0055] Therefore, it is not necessary for the guard part 18a to cover a large area of the rear end surface 14a of the knock part. The area covered by the guard part 18a of the rear end surface 14a of the knock part is, as shown in Figs. 2 and 3, at most a structure that covers about half of the rear end surface 14a of the knock part, which is sufficient. Also, from this perspective, as shown in Fig. 12, the guard part 18c can be made to have an arc-shaped structure that covers a part of the periphery of the rear end surface 14a of the knock part from the rear side when the writing instrument 11b is viewed in the forward direction from the rear side of the writing instrument 11b.

[0056] In the illustrated embodiment, the knock guard portion 17 includes a guard support portion 18 (Figs. 2, 3, 11) that extends from the rear end of the main body 12 in the backward direction, which is the direction from the front end to the rear end, and a guard support portion 18b (Fig. 12).

[0057] And the above-described guard portions 18a and 18c are structured to be supported by the guard support portions 18 and 18b at the rear ends of the guard support portions 18 and 18b, which are the rear ends of the guard support portions (Figs. 2, 3, 11, 12).

[0058] As a result, the guard portions 18a and 18c are structured to be disposed in a position-fixed manner with respect to the rear end of the main body 12 on the rear side of the rear end surface 14a of the knock portion.

[0059] As shown in the drawing, the guard support portions 18 and 18b can be formed integrally with the main body 12. Although not shown in the drawing, the guard support portions 18 and 18b can be separated from the main body 12, and a structure can be adopted in which the guard support portions 18 and 18b of the knock guard portion 17 formed separately from the main body 12 are attached to the rear end of the main body 12.

[0060] Note that, like the writing instrument 11a of the present embodiment illustrated in Fig. 11, the main body 12 can be provided with a tail plug 22 at the rear end, and the guard support portion 18 can be formed integrally with the tail plug 22. In this case, a structure can also be adopted in which the guard support portion 18 and the tail plug 22 are formed separately and the guard support portion 18 is attached to the tail plug 22. Since the writing instrument 11a illustrated in Fig. 11 is the same as the writing instrument 11 described with reference to Figs. 2 and 3 except that the guard support portion 18 is attached to the tail plug 22, the description thereof is omitted.

[0061] In the above-described embodiment, both the guard support portion 18 (Figs. 2, 3) and the guard support portion 18b (Fig. 12) cover a part in the circumferential direction of the outer peripheral surface of the cylindrical knock portion 14 from the outside. The knock portion 14 is adapted to slide in the front-rear direction along the inner wall surface of the guard support portions 18 and 18b.

[0062] In the illustrated embodiment, the length in the front-rear direction of the guard support portion 18 indicated by L3 in FIG. 2(c) is substantially the same as the length in the front-rear direction of the knock portion 14 extending in the rearward direction from the rear end of the main body 12, and the front surfaces of the guard portions 18a and 18c are in contact with the rear end surface 14a of the knock portion (FIGS. 3(a), 11(b), 12(c)).

[0063] As described above, as long as the guard portions 18a and 18c that are fixedly arranged with respect to the rear end of the main body 12 and are located on the rear side of the rear end surface 14a of the knock portion cover at least a part of the rear end surface 14a of the knock portion when the writing instrument 11 is viewed in the forward direction from the rear side of the writing instrument 11. Therefore, the length in the front-rear direction of the guard support portion 18 may be larger than that shown in the figure, and a structure may be adopted in which there is a space in the front-rear direction between the front surfaces of the guard portions 18a and 18c and the rear end surface 14a of the knock portion.

[0064] As described above and shown in the figures, in the writing instruments 11, 11a, and 11b of the present embodiment, the clip portion 16 can be supported by the guard support portion 18. In this case, the clip portion 16 can be integrally formed with the guard support portion 18 constituting the knock guard portion 17, or can be a separate body.

[0065] As described above, the advantage of the structure in which the clip portion 16 is supported by the guard support portion 18 is particularly exhibited by the fact that the position in the front-rear direction of the rear end of the clip portion, which is the rear end of the clip portion 16, and the position in the front-rear direction of the guard portions 18a and 18c are substantially the same (FIGS. 3(a), 11(b), 12(c)).

[0066] As shown in the figure, if the position in the front-rear direction of the rear end of the clip portion, which is the rear end of the clip portion 16, and the position in the front-rear direction of the guard portions 18a and 18c are substantially the same, the portion indicated by L2 in FIG. 2(c) will have a size (length) that protrudes from the edge of the pocket 40 or the edge of the notebook 41 when the writing instrument 11 is inserted into the pocket 40 or the like (FIG. 6).

[0067] As described above, since the length of the portion indicated by this L2 is such that the position in the front-rear direction of the rear end of the clip portion, which is the rear end of the clip portion 16, and the positions in the front-rear direction of the guard portions 18a and 18c are substantially the same, it becomes very small (short) as shown in FIGS. 2(c) and 6.

[0068] Therefore, with such a structure, when the writing instrument 11 is attached to the pocket 40, the notebook 41, the file, etc. and carried or used, there is less protrusion, and malfunction, dropping, etc. can be reduced, which is advantageous.

[0069] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the technical scope understood from the description of the claims.

Claims

1. A cylindrical body that has a taper at the front end and a knock portion at the rear end and extends in the front-rear direction, and a clip portion that is disposed on the rear end side of the body and sandwiches the body between fastening objects. By applying a forward force in the forward direction, which is the direction from the rear end to the front end, to the knock portion to activate the knock, the writing tip protrudes from the opening of the taper in the forward direction and is held in the writing position so that writing can be performed. A knock-type writing instrument, When an unintended forward force is about to be applied to the knock portion, a knock guard portion that prevents the unintended forward force from being applied to the knock portion is provided at the rear end of the body. A writing instrument with an anti-malfunction function.

2. When the writing instrument with an anti-malfunction function is viewed in the forward direction from the rear side of the writing instrument with an anti-malfunction function, the knock guard portion covers at least a part of the rear end surface of the knock portion, which is the rear end surface of the knock portion, and is fixedly disposed with respect to the rear end of the body. A guard portion is provided on the rear side of the rear end surface of the knock portion. The writing instrument with an anti-malfunction function according to Claim 1.

3. The knock guard portion includes a guard support portion that extends from the rear end of the body in the backward direction, which is the direction from the front end to the rear end. The guard portion is supported by the guard support portion at the rear end of the guard support portion, which is the rear end of the guard support portion. The writing instrument with an anti-malfunction function according to Claim 2.

4. The guard support portion is integrally formed with the body or is formed separately from the body. The writing instrument with an anti-malfunction function according to Claim 3.

5. The body has a tail plug at the rear end, and the guard support portion is integrally formed with the tail plug or is formed separately from the tail plug. The writing instrument with an anti-malfunction function according to Claim 3.

6. When the writing instrument with an anti-malfunction function is viewed in the forward direction from the rear side of the writing instrument with an anti-malfunction function, the guard portion covers a part of the periphery of the rear end surface of the knock portion from the rear side and is arc-shaped. The writing instrument with an anti-malfunction function according to Claim 2 or 3.

7. The guard portion is formed of a plate-like body parallel to the rear end surface of the knock portion. The writing instrument with an anti-malfunction function according to Claim 2 or 3.

8. The writing instrument with an anti-malfunction function according to claim 3, wherein the clip portion is supported by the guard support portion.

9. The writing instrument with an anti-malfunction function according to claim 8, wherein a position in the front-rear direction of a rear end of the clip portion, which is the rear end of the clip portion, and a position in the front-rear direction of the guard portion are substantially the same.

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