Side knock type writing instrument

Abstract

To provide a side knock type writing instrument which can be configured with a smaller number of parts and allows easy and reliable forward and backward operation of a writing refill.SOLUTION: The side knock type writing instrument includes a barrel 1, a writing refill 3 movably housed within the barrel, with a writing portion 3a arranged so that it can be protruded and retracted from the front end of the barrel, a spring 4 that applies a biasing force to the writing refill toward the rear end of the barrel, and an operating member 2 that moves within the barrel together with the writing refill and has an integrally molded first operating portion 2c and a second operating portion 2e that are arranged to protrude from a first opening 1c and a second opening 1d formed in the side wall of the barrel, respectively. Operation of the first operating portion moves the writing refill forward within the barrel, causing the writing portion to protrude from the front end of the barrel, and operation of the second operating portion moves the forward-moved writing refill back within the barrel by the biasing force of the spring, allowing the writing portion to be stored within the barrel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a side-knock type writing instrument suitable for use in, for example, a manufacturing site in a factory. [Background technology]

[0002] For example, in manufacturing sites in factories, writing instruments are used for purposes such as recording work, and in many cases, writing instruments are used that have a ballpoint pen refill with a ballpoint pen tip attached to the front end of the ink tube inside the barrel as an interchangeable writing element. However, the above-mentioned writing instruments with replaceable refills are made up of a relatively large number of parts, and there are rare cases where the tip member that is screwed into the tip of the barrel, or the tip barrel that makes up the front half of the barrel, loosens and falls off, resulting in the problem of these parts becoming mixed in as foreign matter on the manufacturing line, etc. In particular, in food factories and pharmaceutical factories, the contamination of foreign matter as described above can lead to more serious problems, and as a preventative measure, measures such as wrapping the tip member and tip barrel with aluminum tape to secure them to the barrel are taken.

[0003] The present applicant has previously proposed a ballpoint pen writing instrument that can be suitably used in factory production sites, etc., and this is disclosed in Patent Document 1. The writing instrument proposed in Patent Document 1 is characterized in that at least the exterior (e.g., barrel, operating parts such as a knock button, cap, and clip) is made of synthetic resin containing magnetic metal powder (e.g., metal powder or iron oxide powder).

[0004] On the other hand, in the above-mentioned writing instrument, a configuration has been proposed in which the writing part can be extended from the front end of the barrel by knocking an operating button located at the rear end of the barrel, and this is disclosed, for example, in Patent Document 2. In response to this, a side-knock type writing instrument has also been proposed in which an operating button is placed on the side of the barrel, and by knocking this button, the writing part is extended from the front end of the barrel. This is disclosed, for example, in Patent Document 3 and Patent Document 4.

[0005] Comparing the two, the former writing instrument, which operates by knocking an operating button located at the rear end of the barrel, requires the operator to change the way he holds the barrel and knock the operating button, whereas the latter side-knock type writing instrument allows the operating button to be knocked by slightly shifting part of the finger holding the barrel. Therefore, the latter side-knock type writing instrument has the advantage that it is easy to change the grip of the barrel when performing the knock operation, and as a result, side-knock type writing instruments are thought to be highly suitable for use in factory manufacturing sites, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-12301 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-203453 [Patent Document 3] Japanese Patent Application Publication No. 8-324181 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-89676 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, the writing instrument disclosed in Patent Document 1 contains magnetic metal powder in the resin parts that make up the outer casing of the writing instrument. This is intended to enable immediate detection by a metal detector, for example, in the event that a part of the writing instrument (such as the tip member or tip barrel) is mixed in as a foreign object on the production line at a manufacturing site. Therefore, for writing implements used in the manufacturing sites described above, it is desirable to employ a structure in which some of the above-mentioned parts will not come off accidentally.

[0008] Furthermore, as a writing instrument to be used in factory manufacturing sites, etc., the value of adopting a side-knock writing instrument can be said to be high, as mentioned above, from the viewpoint that it is easy to change the barrel with one hand when performing the knock operation. However, as described in Patent Document 3, for example, a side-knock writing instrument is equipped with a tip (nose member), a barrel, a clip, a swing element serving as a knock operation button disposed on the side wall of the barrel, and a rotating cam mechanism that fixes the ballpoint pen refill in an advanced or retracted position. The rotating cam mechanism is equipped with many parts, such as a cam body, a rotating cam, and a cam bar that meshes with the rotating cam.

[0009] Furthermore, the writing instrument described in Patent Document 4, which is cited as another example of a side-knock type writing instrument, also requires a large number of parts, such as a tip (tip member), a barrel, a clip, an operating member for operating the knock, and an engaging member that carries a refill and moves due to the action of a cam formed on the operating member. Therefore, there is an increased risk that the above-mentioned parts will accidentally come off and become mixed into the product as foreign matter.

[0010] This invention was made in consideration of the current state of the conventional writing instruments described above, and its objective is to provide a side-knock type writing instrument that can be constructed with a smaller number of parts and that allows the writing refill inside the barrel to be easily and reliably moved forward and backward. [Means for solving the problem]

[0011] The side-knock writing instrument of this invention, which has been made to solve the above-mentioned problems, is a side-knock writing instrument comprising a barrel, a writing refill that is movably housed within the barrel and has a writing part that can be protruded and retracted from the front end of the barrel, a spring that applies a biasing force to the writing refill toward the rear end of the barrel, and an operating member that moves within the barrel together with the writing refill and has an integrally molded first operating part and a second operating part that are arranged to protrude from first and second openings, respectively, formed in the side wall of the barrel, and is characterized in that by operating the first operating part, the writing refill is advanced within the barrel, causing the writing part to protrude from the front end of the barrel, and by operating the second operating part, the writing refill in its advanced state is retracted within the barrel by the biasing force of the spring, allowing the writing part to be stored within the barrel.

[0012] In this case, in a preferred embodiment, the operating member has an engagement / disengagement protrusion that slides within the barrel, which is integrally molded with the first operating part and the second operating part, and when the first operating part is operated, the writing refill moves forward within the barrel, and the engagement / disengagement protrusion engages with an engagement portion provided within the barrel, thereby holding the writing refill in an advanced state, and when the second operating part is operated, the engagement of the engagement protrusion with the engagement portion is released, and the writing refill is moved backward within the barrel by the spring force.

[0013] On the other hand, in addition to the above-mentioned configuration, a tip member is attached to the front end of the barrel, so that the writing part can be protruded and retracted from the tip opening formed in the tip member, one end of the spring abuts against the writing refill, and the other end is positioned abutting within the tip member, a locking protrusion is formed on the peripheral surface of the rear end of the tip member so as to protrude from the peripheral surface, and the front end opening of the barrel is provided with an attachment groove for the locking protrusion, which includes a first guide groove formed from the front end opening toward the rear end of the barrel, a second guide groove formed following the first guide groove along the axis of the inner circumference of the barrel, and a third guide groove formed following the second guide groove and folding back toward the front end opening of the barrel and terminating just before the front end opening, and it is desirable that the tip member be configured so that the locking protrusion of the tip member is attached to the third guide groove and abuts against the terminal end of the third guide groove due to the biasing force of the spring, and the tip member is attached to the front end of the barrel.

[0014] Furthermore, it is desirable that the rear end of the barrel be provided with an opening through which a writing implement can be hung. [Effects of the Invention]

[0015] The side-knock writing instrument according to the present invention includes an operating member that integrates a first operating portion and a second operating portion, the first operating portion and the second operating portion being disposed to protrude from a first opening and a second opening, respectively, formed in the side wall of the barrel. The writing refill moves within the barrel as the operating member moves within the barrel. This allows the writing refill to be advanced within the barrel by operating the first operating portion, causing the writing part to protrude from the tip of the barrel. Furthermore, the writing refill in the advanced state can be retracted within the barrel by operating the second operating portion due to the biasing force of the spring, allowing the writing part to be stored within the barrel.

[0016] According to the writing implement described above, the basic configuration of the side knock type writing implement is formed by the barrel, the operating member, and the spring, excluding the writing refill. Therefore, it is possible to realize a side-knock type writing instrument with an extremely small number of parts and a simplified configuration, which can contribute to the provision of a writing instrument that significantly reduces the risk of parts accidentally coming off and becoming mixed in as foreign matter with the product, for example, on the production line of the factory mentioned above.

[0017] In a side-knock writing instrument equipped with a tip member at the front end of the barrel, the front end opening of the barrel is provided with first through third guide grooves that are connected in a U-shape. The locking protrusion of the tip member, which protrudes from the circumferential surface of the rear end of the tip member, passes through the first through third guide grooves that are connected in a U-shape, allowing the tip member to be attached to the front end opening of the barrel. In this case, the locking protrusion of the tip member is attached to the front end of the barrel in a state of abutting the end of the third guide groove due to the biasing force of the spring, so the locking protrusion of the tip member always remains in abutment with the end of the third guide groove due to the biasing force of the spring. This eliminates the problem of the tip member accidentally falling off the barrel. [Brief explanation of the drawings]

[0018] [Figure 1] 1A and 1B are perspective views showing the external configuration of a side-knock type writing implement according to the present invention, in which FIG. 1A shows a state in which the writing part is protruded, and FIG. 1B shows a state in which the writing part is housed within the barrel. [Figure 2A] 1A and 1B show the overall structure of a side-knock writing implement with the writing part housed in the barrel, where (A) is a top view and (B) is a cross-sectional view of the lower half seen from the axis line in the state shown in (A). [Figure 2B] 1A and 1B show the overall structure of a side-knock type writing implement in which the writing part is housed in a barrel, where (A) is a front view and (B) is a cross-sectional view of the lower half as seen from the axis line in the state shown in (A). [Figure 3A] 1A and 1B show the overall structure of a side-knock type writing implement with a protruding writing part, in which (A) is a top view and (B) is a cross-sectional view of the lower half as seen from the axis in the state shown in (A). [Figure 3B]1A and 1B show the overall structure of a side-knock type writing implement with a protruding writing part, in which (A) is a front view and (B) is a cross-sectional view of the lower half seen from the axis line in the state shown in (A). [Figure 4] FIG. 2 is an exploded view of the components of a side-knock writing instrument. [Figure 5] 10A to 10D are perspective views showing the front end of the writing implement, illustrating in sequence how the tip member is removed from the front end of the barrel. [Figure 6A] The figure shows the single component structure of the barrel, where (A) is a top view and (B) is a cross-sectional view of the lower half seen from the axis line in the state shown in (A). [Figure 6B] The figure shows the individual components of the barrel, where (A) is a front view, (B) is a cross-sectional view of the lower half seen from the axis line in the state shown in (A), and (C) is a left side view. [Figure 7] 1A and 1B show the individual components of the barrel, with FIG. 1A being a perspective view with the front end facing forward, and FIG. 1B being a perspective view with the rear end facing forward. [Figure 8] 1A and 1B show the individual components of the operating member, where (A) is a perspective view with the front end facing forward, (B) is a perspective view with the rear end facing forward, (C) is a top view, and (D) is a front view. [Figure 9A] The individual components of the tip member are shown, with (A) being an oblique view with the front end facing forward, (B) being an oblique view with the rear end facing forward, (C) being a top view, and (D) being a cross-sectional view of the lower half viewed from the axis of the state shown in (C). [Figure 9B] 1A and 1B show the individual components of the tip member, where (A) is a front view, (B) is a cross-sectional view of the lower half viewed from the axis of the state shown in (A), (C) is a left side view, and (D) is a right side view. DETAILED DESCRIPTION OF THE INVENTION

[0019] The side-knock writing instrument according to the present invention will be described based on the embodiment shown in the drawings. In the following drawings, the same parts are designated by the same reference numerals, but in some drawings, due to space limitations, reference numerals are assigned to representative parts, and the details will be described by referring to the reference numerals assigned to the drawings showing the individual components. The overall structure of this side-knock type writing instrument is shown in Figures 1 to 3B, and each of these figures shows the writing part protruding from the tip member attached to the front end of the barrel, and the writing part housed within the tip member, respectively. FIG. 4 shows an exploded view of each component that constitutes the side-knock writing implement shown in FIGS. 1 to 3B.

[0020] This side-knock writing instrument does not have a cap that detachably covers the tip of the writing instrument or a clip that fastens the barrel to, for example, a breast pocket, so that it can be used effectively in factory manufacturing sites, particularly food production lines. With the elimination of the cap, the writing part is configured to be able to protrude and retract from the tip member, and with the elimination of the clip, a strap hole (through hole) is formed at the rear end of the barrel, and a strap (not shown) is passed through this strap hole and hung around the worker's neck, thereby preventing the writing instrument from being lost. A tip member is detachably attached to the front end of the barrel, and is configured so that a ballpoint pen refill that functions as a writing refill can be replaced.

[0021] As shown in the exploded view of parts in FIG. 4, the side knock type writing instrument of this embodiment comprises a barrel 1 It is composed of an operating member 2 that is inserted into the barrel 1 from the front end opening of the barrel 1, a writing refill 3 that is inserted into the barrel 1 through a hollow portion formed along the axis of the operating member 2, a coil-shaped spring 4 that has one end abutting a part of the writing refill 3 and the other end abutting inside the tip member 5, and the tip member 5 that is detachably attached to the front end opening of the barrel 1. A part of the writing refill 3 and the other parts except for the spring 4 are made of a resin material.

[0022] The individual components of the barrel 1 are shown in FIGS. 6A, 6B and 7. FIG. The front half of the barrel 1 is formed in a roughly cylindrical shape, and the rear half has an outer diameter that tapers toward the rear. A pair of elongated surfaces, a first surface 1a1 and a second surface 1a2, are formed axially symmetrically in the rear half of the barrel 1. In addition, a strap hole 1b is formed through the barrel 1 so as to be perpendicular to the opposing first surface 1a1 and second surface 1a2 at the rear end of the barrel, and a strap (not shown) can be passed through this strap hole 1b and worn around the neck, for example, to prevent the writing instrument from being lost.

[0023] A first opening 1c that is connected to the inside of the barrel 1 is formed long in the axial direction by forming a chamfered state on the cylindrical side surface of the front half of the barrel 1. A first operating portion 2c formed on the operating member 2, which will be described later, is disposed in this first opening 1c so as to protrude from the barrel 1. Furthermore, a second opening 1d that communicates with the interior of the barrel 1 is formed along the axial direction on the side of the barrel 1 that is rotated 90 degrees from the first opening 1c by similarly chamfering the side along the longitudinal direction. The opening length and opening width of this second opening 1d are each smaller than those of the first opening 1c. A second operating portion 2e formed on the operating member 2, which will be described later, is disposed in this second opening 1d so as to protrude from the interior of the barrel 1.

[0024] Furthermore, a short third opening 1e is formed immediately after the second opening 1d, and the opening width of this third opening 1e is formed to be the same as the opening width of the second opening 1d. The third opening 1e is where an engaging / disengaging protrusion 2f integrally formed with the operating member 2, which will be described later, is disposed. The rear end portions of the second opening 1d and the third opening 1e are not subjected to the above-mentioned chamfering, and are formed with surfaces perpendicular to the axis of the barrel 1 as shown in the drawing. This allows the rear ends of the second opening 1d and the third opening 1e to function as a first engaged portion 1d1 and a second engaged portion 1e1 that can reliably engage with an engaging / disengaging protrusion 2f formed on the operating member 2, which will be described later. In this embodiment, the first opening 1c and the second opening 1d are formed at positions that are rotated 45 degrees from each other with respect to the first surface 1a1 formed on the barrel 1. In other words, the first surface 1a1 is formed on the rear end side of the barrel 1 between the first opening 1c and the second opening 1d.

[0025] A mounting groove for detachably mounting a tip member 5 is provided in the front end opening of the barrel 1. As shown in (B) of Figure 6A, for example, this mounting groove comprises a first guide groove 1f formed from the front end opening toward the rear end side of the barrel 1, a second guide groove 1g formed following the first guide groove 1f along the axis of the inner circumference of the barrel 1, and a third guide groove 1h formed following the second guide groove 1g and folding back toward the front end opening of the barrel 1 and terminating in an end portion 1i just before the front end opening.

[0026] The mounting grooves of the tip member 1, consisting of the first guide groove 1f, the second guide groove 1g, and the third guide groove 1h, are similarly formed in an axially symmetrical manner on the opposing inner surfaces within the front end opening of the barrel 1. Then, the locking protrusion 5c formed on the tip member 5, which will be described later, is inserted along the first guide groove 1f, second guide groove 1g, and third guide groove 1h, which are formed in a U-shape, and the tip member 5 is attached to the tip of the barrel 1. In this embodiment, the second guide groove 1g, the third guide groove 1h and their terminal ends 1i penetrate to the outside of the barrel 1 and form openings in the side wall of the barrel 1.

[0027] A fourth guide groove 1j (see Fig. 4, Fig. 6A(B), and Fig. 6B(C)) is formed in the front end opening of the barrel 1, extending from the front end opening to the first opening 1c. The first guide groove 1f located on the second opening 1d side is formed by linearly extending the first guide groove 1f from the second opening 1d to the third opening 1e (see Fig. 6B(B)). The fourth guide groove 1j and the first guide groove 1f, which is formed by extending from the second opening 1d to the third opening 1e, are formed to facilitate the insertion of the first operating portion 2c, the second operating portion 2e, and the engagement / disengagement protrusion 2f, which will be described later, formed on the operating member 2, when the operating member 2 is elastically deformed and inserted into the front end opening of the barrel 1 during assembly of the writing instrument.

[0028] The individual structure of the operating member 2 is shown in FIG. The operating member 2 is made of an elastically deformable resin material, and has a circular contact portion 2a at its front end for contacting the writing refill. A guide body 2b extends rearward along approximately half the circumference of the contact portion 2a and is molded in such a way that the cylindrical body is split in half along the axial direction. Therefore, the ink collection tube 3c of the ballpoint pen refill described below as the writing refill 3 can be accommodated and arranged within the barrel 1 via the annular abutment portion 2a and the hollow portion along the inner surface of the guide body 2b.

[0029] A first operating portion 2c is formed on the outer surface of the guide body 2c in a state where it protrudes outward. Additionally, a thin and long engaging / disengaging piece 2d is formed from the annular contact portion 2a toward the rear, adjacent to the guide body 2c in the circumferential direction, and the rear end of this engaging / disengaging piece 2d is formed so as to be spaced outward relative to the axis of the operating member 2 (see Fig. 8(D)). A second operating portion 2e is formed at approximately the center of the length of the engaging / disengaging piece 2d in a state of protruding outward from the engaging / disengaging piece 2d. Furthermore, an engagement / disengagement protrusion 2f is formed at the rear end of the engagement / disengagement piece 2d in an upright position facing outward, and a bending suppression piece 2g is formed at the inside of the rear end of the engagement / disengagement piece 2d in a folded position facing forward. The protruding direction of the second operating portion 2e and the engaging / disengaging protrusion 2f molded on the engaging / disengaging piece 2d is formed at an angle of 90 degrees relative to the protruding direction of the first operating portion 2c formed on the outer surface of the guide body 2b.

[0030] The writing refill 3 used in this embodiment is shown in central cross-sectional views along the axis in Figures 2A, 2B, 3A, and 3B, and in a perspective view in Figure 4. This writing refill 3 has a ballpoint pen tip 3a made of a metal material in the writing portion, and this ballpoint pen tip 3a constitutes a ballpoint pen refill connected to an ink reservoir 3c via a relay member 3b. As shown in the figure, the relay member 3b has a large diameter portion 3b1 that covers the front end of the ink containing tube 3c from the outside, and the annular abutment portion 2a of the operating member 2 mentioned above abuts against the rear end of this large diameter portion 3b1, thereby moving the writing refill 3 forward within the barrel 1.

[0031] On the other hand, the coil spring 4 is shown in a perspective view in Fig. 4, for example, and is made of a metal material as is well known. The rear end of the spring 4 is attached so as to surround the writing part (ballpoint pen tip) 3a and is disposed in contact with the large diameter part 3b1 of the relay member 3b. In addition, the front end of the spring 4 abuts against a part of the inside of the tip member 5 described below, so that when the spring 4 exerts an axial expanding force, the writing refill 3 is subjected to a force that causes it to retreat within the barrel 1, and the tip member 5 is subjected to a force that causes it to protrude forward from the barrel 1.

[0032] The individual components of the prong member 5 are shown in Figures 9A and 9B. The front half of the tip member 5 is formed in a conical shape, and an opening 5a is provided at the tip of the cone, and the writing part 3a of the writing refill 3 appears and disappears through this tip opening 5a. The conical portion has a pair of recesses 5b formed along the axis at axially symmetrical positions. These recesses 5b function as anti-slip devices when attaching or detaching the tip member 5 to the front end of the barrel 1. It should be noted that a larger number of recesses 5b can be arranged at equal intervals along the conical surface, and the number is arbitrary.

[0033] The rear half of the tip member 5 is formed in a cylindrical shape, and a pair of locking projections 5c are formed at axially symmetrical positions on this cylindrical portion so as to protrude from the cylindrical surface. This locking protrusion 5c is inserted along the first guide groove 1f, second guide groove 1g, and third guide groove 1h formed in the front end opening of the barrel 1, thereby allowing the tip member 5 to be detachably attached to the front end opening of the barrel 1; the attachment and detachment operation will be described later.

[0034] The inside diameter of the tip member 5 decreases in a stepped manner from the rear end opening to the tip opening 5a, and six rib members 5d are arranged at equal intervals along the inner circumference at approximately the center of the tip member 5 in the front-to-back direction, protruding toward the axis. The rear half of each rib member 5d is formed so that its axial protrusion height narrows toward the front, while the front half of each rib member 5d is formed so that its axial protrusion height remains substantially constant toward the front. The front end of each rib member 5d has a stepped inner diameter, and one of these stepped portions forms the abutment portion 5e for the front end of the spring 4.

[0035] To assemble the above-described components into the writing implement shown in FIGS. 1 to 3B, first, the operating member 2 must be inserted into the front end opening of the barrel 1 and attached. 4, the rear end of the guide body 2b of the operating member 2 is faced toward the front end opening of the barrel 1, and the first operating part 2c and the second operating part 2e of the operating member 2 are aligned so as to face the fourth guide groove 1j and the first guide groove 1f of the front end opening of the barrel 1. In this state, the engaging / disengaging piece 2d of the operating member 2 is elastically deformed in the axial direction, and the operating member 2 is pushed into the front end opening of the barrel 1.

[0036] At this time, as already explained, the guide body 2b of the operating member 2 is molded in a state in which a cylinder is split in half along the axial direction, so that the operating member 2 can be inserted into the barrel 1 with the rear end of the guide body 2b slightly tilted toward the axial center of the barrel 1. As a result, the first operating portion 2c, the second operating portion 2e and the engagement / disengagement protrusion 2f of the operating member 2 are set in a protruding state from the first opening 1c, the second opening 1d and the third opening 1e of the barrel 1, respectively.

[0037] With the operating member 2 set in the barrel 1 as described above, the rear end of the ink storage tube 3c of the writing refill 3 is inserted into the annular abutment portion 2a of the operating member 2, thereby storing the writing refill 3 in the barrel 1. The rear end of the large diameter portion 3b1 formed on the writing refill 3 is then brought into abutment with the annular abutment portion 2a of the operating member 2. Next, a coil spring 4 is attached so as to cover the tip writing portion 3a of the writing refill 3, and a tip member 5 is attached to the front end opening of the barrel 1, thereby assembling the side knock type writing implement.

[0038] When attaching the tip member 5 to the front end opening of the barrel 1, the locking projection 5c formed on the tip member 5 is aligned with the first guide groove 1f formed in the front end opening of the barrel 1, and the rear cylindrical portion of the tip member 5 is inserted into the front end opening of the barrel 1. As a result, the locking projection 5c of the tip member 5 moves through the first guide groove 1f and reaches the second guide groove 1g.

[0039] In this state, by rotating the tip member 5 clockwise relative to the barrel 1, the locking protrusion 5c moves along the second guide groove 1g and reaches the third guide groove 1h. When the locking protrusion 5c reaches the third guide groove 1h, it receives the biasing force of the spring 4 and moves forward along the third guide groove 1h, and the locking protrusion 5c is pressed against the terminal end 1i of the third guide groove 1h. This keeps the tip member 5 stably attached to the front end opening of the barrel 1, and prevents the tip member 5 from loosening and falling off unnoticed.

[0040] Figure 5 shows the procedure for removing the tip member 5 from the barrel 1. This is the reverse of the procedure for attaching the tip member 5 to the barrel 1 described above, so the procedure for removing the tip member 5 will be briefly explained below. In the state shown in Figure 5(A), the tip member 5 is subjected to a biasing force from the spring 4 in a direction pushing it out from the front end opening of the barrel 1. Therefore, by performing an operation to push the tip member 5 into the barrel 1, the locking protrusion 5c retreats from the third guide groove 1h as shown in Figure 5(B). In this state, by rotating the tip member 5 counterclockwise relative to the barrel 1, the locking protrusion 5c moves within the second guide groove 1g and moves toward the first guide groove 1f as shown in Figure 5(C). By pulling the tip member 5 out of the barrel in this state, the tip member 5 can be removed from the barrel 1 as shown in Figure 5(D).

[0041] In the side-knock writing instrument configured as described above, the first operating portion 2c protruding from the peripheral side surface of the barrel 1 is slid forward, causing the operating member 2 to move forward within the barrel 1. As a result, the annular abutment portion 2a of the operating member 2 abuts against the large diameter portion 3b1 of the writing refill 3, pushing out the writing refill 3, and the tip writing portion 3a protrudes from the tip opening 5a of the tip member 5 (see Figures 1(A), 3A, and 3B). As the operating member 2 moves forward, the engaging / disengaging protrusion 2f formed on the operating member 2 slides from the third opening 1e along the inner surface of the barrel 1 to the second opening 1d, where it engages with the first engaged portion 1d1 of the second opening 1d. This keeps the tip writing portion 3a protruding from the tip opening 5a of the tip member 5.

[0042] When the tip writing portion 3a protrudes from the tip opening 5a of the tip member 5, a knocking operation is performed to push the second operating portion 2e into the barrel 1, causing the engagement / disengagement piece 2d to bend in the axial direction, and the engagement / disengagement protrusion 2f molded at the rear end of the engagement / disengagement piece 2d to be released from its engagement with the first engagement portion 1d1 formed in the second opening 1d. As a result, the biasing force of the spring 4 causes the operating member 2 to retract within the barrel 1 together with the writing refill 3, and the tip writing portion 3a is housed within the tip member 5. Then, the engaging / disengaging protrusion 2f slides along the inner surface of the barrel 1 and enters the third opening 1e, where it is engaged with the second engaged portion 1e1 formed in the third opening 1e (see Figures 1(B), 2A, and 2B).

[0043] As already explained, a bending-preventing piece 2g is molded on the rear end of the engaging / disengaging piece 2d of the operating member 2. When excessive pressure is applied to the second operating part 2e during the knocking operation that pushes the second operating part 2e into the barrel 1, this bending-preventing piece 2g comes into contact with the side surface of the ink containing tube 3c of the writing refill 3. This prevents the engaging / disengaging piece 2d that forms the second operating part 2e and the like from bending excessively and being damaged, such as by breakage. Furthermore, the bending suppression piece 2g can also contribute to preventing the engagement / disengagement protrusion 2f from entering the rear side of the third opening 1e due to excessive bending of the engagement / disengagement piece 2d, which would put the writing implement in a malfunction state.

[0044] As already explained, the protruding direction of the second operating part 2e is formed at an angle of 90 degrees to the protruding direction of the first operating part 2c, and a first surface 1a1 is formed in the rear half of the barrel 1 between them, and a second surface 1a2 is formed on the back side of the first surface 1a1 in an axially symmetrical manner. This allows, for example, the second surface 1a2 to be placed between the thumb and index finger, and the first operating part 2c to be slid with the thumb and the second operating part 2e to be knocked with the index finger, thereby contributing to providing a writing instrument with improved operability.

[0045] As is clear from the above explanation, the side-knock writing instrument according to the present invention can realize a writing instrument with an extremely small number of parts and a simplified configuration, as explained, for example, based on Figure 4. Therefore, it is possible to obtain the unique effects described in the "Effects of the Invention" section above, such as contributing to the provision of a writing instrument that significantly reduces the risk of parts accidentally coming loose on a factory production line, etc., and becoming mixed in with the product as foreign matter. Furthermore, the writing instrument of this invention can be used not only in the manufacturing site of the factory mentioned above, but also by general users, etc., as it allows the writing refill to be advanced and retracted easily and reliably. [Explanation of symbols]

[0046] 1 shaft cylinder 1a1 First side 1a2 Second side 1b Strap hole 1c 1st opening 1d 2nd opening 1d1 First engaged part 1e 3rd opening 1e1 Second engaged part 1f First guide groove 1g Second guide groove 1h Third guide groove 1i Termination 2 Operating member 2a Contact part 2c 1st operation section 2d detachable piece 2e 2nd operation section 2f Engagement / disengagement protrusion 2g bending suppression piece 3 Writing refills (ballpoint pen refills) 3a Writing part (ballpoint pen tip) 3b Relay member 3b1 Large diameter part 3c Ink collection pipe 4 Spring 5 Tip member 5a Tip opening 5c Locking protrusion

Claims

1. A side-knock type writing implement comprising: a barrel; a writing refill movably accommodated within the barrel and having a writing portion that can be projected and retracted from the front end of the barrel; a spring that applies a biasing force to the writing refill toward the rear end of the barrel; and an operating member that moves within the barrel together with the writing refill and has integrally molded first and second operating portions that are respectively positioned to protrude from first and second openings formed in a side wall of the barrel, A side-knock type writing instrument characterized in that, by operating the first operating part, the writing refill is advanced within the barrel, causing the writing part to protrude from the front end of the barrel, and by operating the second operating part, the writing refill in its advanced state is retracted within the barrel by the spring force, allowing the writing part to be stored within the barrel.

2. The operating member has an engaging / disengaging protrusion that slides within the barrel, and is integrally formed with the first operating portion and the second operating portion, By operating the first operating portion, the writing refill advances within the barrel, and the engaging / disengaging protrusion engages with an engaging portion provided within the barrel, thereby maintaining the writing refill in an advanced state; The side-knock type writing instrument according to claim 1, characterized in that, by operating the second operating part, the engagement of the engagement protrusion with the engaged part is released, and the writing refill is retracted within the barrel by the spring force.

3. A tip member is attached to the front end of the barrel, and the writing part is configured to be able to appear and disappear from a tip opening formed in the tip member, and one end of the spring abuts against the writing refill, and the other end is disposed in abutment within the tip member, A locking projection is formed on the peripheral surface of the rear end of the tip member in a state where it protrudes from the peripheral surface, and a mounting groove for the locking projection is provided in the front end opening of the barrel, the mounting groove including a first groove formed from the front end opening toward the rear end side of the barrel, a second groove formed following the first groove along the axis of the inner circumference of the barrel, and a third groove formed following the second groove and folding back toward the front end opening of the barrel and terminating just before the front end opening, A side-knock type writing instrument as described in claim 1 or 2, characterized in that the tip member is attached to the front end of the barrel with the locking protrusion of the tip member attached to the third groove and abutting against the terminal end of the third groove by the spring force.

4. 3. A side-knock type writing implement according to claim 1 or 2, wherein an opening is provided at the rear end of the barrel to enable the writing implement to be hung.

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