Applicator

Abstract

To provide an applicator that can improve the accuracy of circumferential alignment between components that are spaced apart in the axial direction compared to when a plurality of components are joined by screwing.SOLUTION: An applicator 1 (1A, 1B) includes a shaft portion (10) having an L-shaped first recess (12) that opens to the rear side, a tail plug (40) having an L-shaped second recess (42) that opens to the front side, and an intermediate shaft (50) including a front end portion (54) on whose outer surface a first convex portion (51) that engages with the first recess (12) is provided and which is coupled to the shaft portion (10) by engagement between the first recess (12) and the first convex portion (51), and a rear end portion (55) on whose outer surface a second convex portion (52) that engages with the second recess (42) is provided and which is coupled to the tail plug (40) by engagement between the second recess (42) and the second convex portion (52).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an applicator. [Background technology]

[0002] BACKGROUND ART Applicators that are configured by assembling a plurality of parts have been known in the past. For example, Patent Documents 1 and 2 describe writing implements that are constructed by assembling a plurality of parts.

[0003] Although parts of an applicator are generally joined by screwing, Patent Documents 1 and 2 also describe the use of engagement between an L-shaped groove and an engaging portion as a means of joining parts. Specifically, in Patent Document 1, an L-shaped groove (engagement receiving portion) is provided on the inner surface of the barrel, and an engagement protrusion is provided on the outer surface of the tip, so that the L-shaped groove and the engagement protrusion are engaged when assembling the writing instrument. Similarly, in Patent Document 2, an engagement portion is provided on the outer surface of the barrel holder, and an L-shaped groove is provided in the rear end support portion, so that the engagement portion of the barrel holder is engaged with the L-shaped groove in the rear end support portion when assembling the writing instrument. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-178000 [Patent Document 2] Japanese Patent Publication No. 2023-170323 Summary of the Invention [Problem to be solved by the invention]

[0005] However, from the viewpoint of improving the design of the applicator, it is sometimes required to align parts spaced apart in the axial direction in the circumferential direction. For example, if the front shaft located at the front side of the applicator and the tail plug located at the rear end of the applicator each have a pattern or shape that is not uniform in the circumferential direction, it may be desirable to improve the design of the applicator as a whole by aligning the circumferential positions of the front shaft and tail plug.

[0006] Threaded engagement is a common method for connecting multiple components that make up a sprayer. However, in the case of a sprayer in which multiple components are connected by threaded engagement, it is difficult to align the components that are spaced apart in the axial direction with high precision in the circumferential direction. This is because the circumferential positions of the components spaced apart in the axial direction vary due to the sum of the tolerances of each component in the threaded portion.

[0007] Patent Documents 1 and 2 also do not describe a configuration for realizing highly accurate alignment in the circumferential direction between components that are positioned apart in the axial direction.

[0008] In view of the above circumstances, at least some embodiments of the present invention aim to provide an applicator that can improve the circumferential alignment accuracy between parts that are axially spaced apart, compared to when multiple parts are joined by screwing. [Means for solving the problem]

[0009] In at least some embodiments of the present invention, an applicator comprises: a shaft portion having an L-shaped first recess portion that opens to the rear side; a tail plug having an L-shaped second recess that opens to the front side; an intermediate shaft including a front end portion having a first protrusion on its outer peripheral surface that engages with the first recess, and coupled to the shaft portion through engagement between the first protrusion and the first recess; and a rear end portion having a second protrusion on its outer peripheral surface that engages with the second recess, and coupled to the tail plug through engagement between the second protrusion and the second recess; Equipped with. [Effects of the Invention]

[0010] According to at least some embodiments of the present invention, the first convex portion provided at the front end of the intermediate shaft is engaged with the L-shaped first recess of the shaft portion, and the second convex portion provided at the rear end of the intermediate shaft is engaged with the L-shaped second recess of the tail plug, thereby enabling highly accurate circumferential alignment of the shaft portion and the tail plug. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of an applicator according to an embodiment. [Figure 2] FIG. 1 is an exploded perspective view of an applicator according to an embodiment. [Figure 3] FIG. 1 is a cross-sectional view of an applicator according to an embodiment. [Figure 4] FIG. 10 is a perspective view showing how an intermediate shaft is assembled to a front shaft part of the sprayer according to one embodiment. [Figure 5] FIG. 10 is a cross-sectional view of an applicator according to another embodiment. [Figure 6] FIG. 10 is a cross-sectional perspective view of a shaft portion of an applicator according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0013] FIG. 1 is a perspective view of an applicator according to one embodiment, showing the internal structure of the applicator with some components transparent. FIG. 2 is an exploded perspective view of an applicator according to one embodiment. FIG. 3 is a cross-sectional view of an applicator according to one embodiment. FIG. 4 is a perspective view showing how an intermediate shaft is assembled to a front shaft part of a sprayer according to one embodiment. In the following description, when referring to several embodiments including applicator 1A according to the embodiment shown in Figures 1 to 4 and applicator 1B according to another embodiment described below with reference to Figures 5 and 6, the term applicator 1 may be used. In this specification, the term "front" refers to the tip side of applicator 1 (the pen tip 72 side), and the term "rear" refers to the rear end side of applicator 1.

[0014] In some embodiments, as shown in Figures 1 to 3, the applicator 1 includes a shaft portion 10, a tail plug 40, and an intermediate shaft 50 including a front end portion 54 and a rear end portion 55 that are connected to the shaft portion 10 and the tail plug 40, respectively.

[0015] Applicator 1 has a configuration that allows it to supply a liquid or gel to an object to be applied from applicator part 2 at the tip side of applicator 1. The use of applicator 1 is not particularly limited, and applicator 1 may be a writing instrument for writing with ink or a cosmetic instrument for applying cosmetics. 1 to 3, the exemplary embodiment is a direct ink marking pen that can supply ink stored in the internal space 4 of the ink tank 3 serving as the intermediate shaft 50 from the pen tip 72 (applicator part 2) to a writing surface. The internal space 4 of the ink tank 3 contains an agitating ball 5 for agitating the ink. In other embodiments, the writing implement serving as the applicator 1 is a batting-type marking pen, or a writing implement other than a marking pen (such as a felt-tip pen, marker, or brush pen).

[0016] The shaft portion 10 has a first recess 12 that opens to the rear side. The first recess 12 is provided radially outward of a circular opening 11 of the shaft portion 10 and communicates with the opening 11, as shown in FIG. The first recess 12 is an L-shaped recess including an axial recess 12A and a bent recess 12B bent from the front end of the axial recess 12A. As shown in FIGS. 1 to 2 and 4, the axial recess 12A extends along the axial direction of the applicator 1. In contrast, the bent recess 12B extends in a direction (circumferential direction) perpendicular to the axial direction of the applicator 1. In other words, the bent recess 12B is formed by recessing one of a pair of side wall surfaces 13 (see FIG. 4) that define the axial recess 12A in a direction (circumferential direction) perpendicular to the axial direction. 1, 2, and 4, the front end of the axial recess 12A is closed by the front wall 15 of the first recess 12, while the rear end of the axial recess 12A is open to the rear side. In this way, a first protrusion 51 of the intermediate shaft 50, which will be described later, can enter the axial recess 12A of the first recess 12 from the rear. In order to assist the first protrusion 51 of the intermediate shaft 50 in entering the axial recess 12A from the rear, a tapered portion may be provided on the rear end side of the axial recess 12A to widen the width of the entrance of the first recess 12.

[0017] In one embodiment, the first recess 12 is an L-shaped slit provided in a part of the shaft portion 10 that has the first recess 12. In another embodiment, the first recess 12 is an L-shaped groove provided in the inner circumferential surface of a shaft member that constitutes the shaft portion 10. In the exemplary embodiment shown in Figures 1 to 2 and 4, the first recess 12 is an L-shaped first slit 16 provided in a part of the shaft part 10 that has the first recess 12 (a front shaft part 21 described below).

[0018] In some embodiments, a plurality of first recesses 12 are provided at a plurality of locations in the circumferential direction of the applicator 1. In one embodiment, a pair of first recesses 12 are arranged at 180-degree intervals in the circumferential direction of the applicator 1. In the exemplary embodiment shown in Fig. 4, the axial recesses 12A of the pair of first recesses 12 are provided at circumferential positions corresponding to a pair of corners that face each other across the central axis of the applicator 1, out of four corners (corners) of a rectangular column portion 22 of a part of the shaft portion 10 that has the first recesses 12 (a front shaft part 21, described below). Furthermore, when the prismatic shape of the shaft is triangular or hexagonal, first recesses 12 may be arranged at three locations at 120-degree intervals in the circumferential direction of applicator 1. In other words, the locations of first recesses 12 can be selected appropriately as long as they are arranged at equal intervals in the circumferential direction in accordance with the prismatic shape of the shaft.

[0019] The tail plug 40 has a second recess 42 that opens to the front side. The second recess 42 is provided radially outward of the circular opening 41 of the tail plug 40 and communicates with the opening 41, as shown in FIG. The second recess 42 is an L-shaped recess including an axial recess 42A and a bent recess 42B bent from the rear end of the axial recess 42A. As shown in FIGS. 1 and 2, the axial recess 42A extends along the axial direction of the applicator 1. In contrast, the bent recess 42B extends in a direction (circumferential direction) perpendicular to the axial direction of the applicator 1. In other words, the bent recess 42B is formed by recessing one of a pair of side wall surfaces 43 (see FIGS. 1 and 2) that define the axial recess 42A in a direction (circumferential direction) perpendicular to the axial direction. 1 and 2, the rear end of the axial recess 42A is closed by a rear wall 45, whereas the front end of the axial recess 42A is open to the front side. Thus, a second protrusion 52 of the intermediate shaft 50, which will be described later, can enter the axial recess 42A of the second recess 42 from the front. In the exemplary embodiment shown in FIGS. 1 and 2, in order to assist the second protrusion 52 of the intermediate shaft 50 in entering the axial recess 42A from the front, a tapered portion 42C is provided on the front end side of the axial recess 42A of the second recess 42 to widen the width of the entrance of the second recess 42. That is, the second recess 42 includes the tapered portion 42C located on the front end side of the axial recess 42A, and the width of the second recess 42 widens toward the front at the tapered portion 42C.

[0020] In one embodiment, the second recess 42 is an L-shaped slit provided in the tail plug 40. In another embodiment, the second recess 42 is an L-shaped groove provided in the inner circumferential surface of the tail plug 40. In the exemplary embodiment shown in FIGS. 1 and 2, the second recess 42 is an L-shaped slit 46 provided in the tail plug 40.

[0021] In some embodiments, a plurality of second recesses 42 are provided at a plurality of locations in the circumferential direction of the applicator 1. In the exemplary embodiment shown in FIG. 2, a pair of second recesses 42 are arranged at intervals of 180 degrees in the circumferential direction of the applicator 1.

[0022] The intermediate shaft 50 includes a front end 54 having a first protrusion 51 provided on the outer peripheral surface thereof, and a rear end 55 having a second protrusion 52 provided on the outer peripheral surface thereof. The front end 54 and rear end 55 of the intermediate shaft 50 are cylindrical and can be inserted into the circular opening 11 of the shaft portion 10 and the circular opening 41 of the tail plug 40, respectively. In other words, the outer diameter of the cylindrical front end 54 of the intermediate shaft 50 corresponds to the inner diameter of the opening 11 of the shaft portion 10, and the outer diameter of the cylindrical rear end 55 of the intermediate shaft 50 corresponds to the inner diameter of the opening 41 of the tail plug 40.

[0023] The first protrusion 51 of the intermediate shaft 50 engages with the L-shaped first recess 12 of the shaft portion 10. The front end portion 54 of the intermediate shaft 50 is coupled to the shaft portion 10 by the engagement of the first protrusion 51 with the first recess 12. In the exemplary embodiment shown in Figure 4, the width W1 of the first convex portion 51 in a direction perpendicular to the axial direction (circumferential direction) of the applicator 1 corresponds to the width W2 of the axial recess 12A of the first recess 12 (W1 ≒ W2), and the width W3 of the first convex portion 51 in the axial direction of the applicator 1 corresponds to the width W4 of the bending recess 12B of the first recess 12 (W3 ≒ W4). Therefore, when the intermediate shaft 50 is assembled to the shaft section 10, the first convex portion 51 moves in the axial direction until it abuts against the front wall 15 of the axial recessed portion 12A, and when the intermediate shaft 50 is rotated clockwise in this state, the first convex portion 51 enters the bending recessed portion 12B. With the intermediate shaft 50 assembled to the shaft section 10, the first convex portion 51 engages with the bending recessed portion 12B of the first recessed portion 12. When the intermediate shaft 50 is to be removed from the shaft section 10, the intermediate shaft 50 is rotated counterclockwise to move the first convex portion 51 from the bending recessed portion 12B to the axial recessed portion 12A, and then the intermediate shaft 50 is moved rearward to remove the first convex portion 51 from the axial recessed portion 12A.

[0024] The second protrusion 52 of the intermediate shaft 50 engages with the L-shaped second recess 42 of the tail plug 40. The rear end 55 of the intermediate shaft 50 is coupled to the tail plug 40 by the engagement of the second protrusion 52 with the second recess 42. In one embodiment, the dimensional relationship between the second convex portion 52 and the second concave portion 42 is the same as the dimensional relationship between the above-described first convex portion 51 and the first concave portion 12. That is, the width of the second convex portion 52 in a direction perpendicular to the axial direction of the applicator 1 corresponds to the width of the axial concave portion 42A of the second concave portion 42, and the width of the second convex portion 52 in the axial direction of the applicator 1 corresponds to the width of the bending concave portion 42B of the second concave portion 42. In this case, when the tail plug 40 is assembled to the intermediate shaft 50, the second convex portion 52 moves in the axial direction until it abuts against the rear wall 45 of the axial recessed portion 42A, and when the tail plug 40 is rotated clockwise in this state, the second convex portion 52 enters the bent recessed portion 42B. With the tail plug 40 assembled to the intermediate shaft 50, the second convex portion 52 engages with the bent recessed portion 42B of the second recessed portion 42. When the tail plug 40 is to be removed from the intermediate shaft 50, the tail plug 40 is rotated counterclockwise to move the second convex portion 52 from the bent recessed portion 42B to the axial recessed portion 42A, and the tail plug 40 is then further moved rearward to remove the second convex portion 52 from the axial recessed portion 42A.

[0025] In some embodiments, the bending directions of the bending recess 12B of the first recess 12 and the bending recess 42B of the second recess 42 are set to be opposite to each other in order to align the rotation direction of the intermediate shaft 50 when the intermediate shaft 50 is attached to or detached from the shaft portion 10 with the rotation direction of the tail plug 40 when the tail plug 40 is attached to or detached from the intermediate shaft 50. 2, when viewed from the rear of the applicator 1, in the first recess 12, the bending recess 12B extends clockwise from the axial recess 12A, whereas in the second recess 42, the bending recess 42B extends counterclockwise from the axial recess 42A. In this case, when assembling the intermediate shaft 50 to the shaft portion 10, by rotating the intermediate shaft 50 clockwise, the first protrusion 51 of the intermediate shaft 50 engages with the bending recess 12B of the first recess 12. Furthermore, when assembling the tail plug 40 to the intermediate shaft 50, by rotating the tail plug 40 clockwise, the second protrusion 52 of the intermediate shaft 50 engages with the bending recess 42B of the second recess 42.

[0026] In some embodiments, as shown in FIGS. 1 to 3, the shaft portion 10 includes a front shaft portion 20 located in front of the intermediate shaft 50 and an outer cylinder portion 30 that covers the intermediate shaft 50. The front shaft portion 20 has a first recess 12 at its rear end. The outer cylinder portion 30 is an exterior portion that forms at least a part of the outer shape of the applicator 1. The outer cylinder portion 30 may cover not only the intermediate shaft 50 but also the first recessed portion 12 at the rear end of the front shaft portion 20. Furthermore, the outer cylinder portion 30 may cover the second recessed portion 42 of the tail plug 40 in addition to the intermediate shaft 50 and the first recessed portion 12 of the front shaft portion 20. In the exemplary embodiment shown in FIGS. 1 to 3 , the first recessed portion 12 of the front shaft portion 20, the intermediate shaft 50, and the second recessed portion 42 of the tail plug 40 are housed inside the outer cylinder portion 30.

[0027] In some embodiments, the front shaft portion 20 and the outer cylinder portion 30 are configured as separate parts (21, 31) that can be separated from each other. In the embodiment shown in FIGS. 1 to 4, shaft portion 10 is an assembly of multiple parts including front shaft part 21 and outer cylinder part 31. In this case, front shaft part 20 is formed by front shaft part 21 having first recess 12 at its rear end, and outer cylinder part 30 is formed by outer cylinder part 31 that is detachable from front shaft part 21. Outer cylinder part 31 has a front end opening 32 into which the rear end of front shaft part 21 fits. Front shaft part 21 is assembled to outer cylinder part 31 by fitting the rear end of front shaft part 21 into front end opening 32, and shaft portion 10 including front shaft part 21 and outer cylinder part 31 is formed. In some other embodiments, as will be described later with reference to FIGS. 5 and 6, the shaft portion 10 is a single-piece molded product including the front shaft portion 20 and the outer cylinder portion 30.

[0028] 1, 2, and 4, the rear end of the front shaft part 21 is prismatic, and the front end opening 32 of the outer cylinder part 31 has a complementary angular shape to the rear end of the front shaft part 21. This allows the outer cylinder part 31 to be attached to the front shaft part 21 so as not to be rotatable in the circumferential direction. Specifically, front shaft part 21 has a prismatic portion 22 having a prismatic outer shape with first slits 16 formed on the rear end side as first recesses 12. Here, "prismatic" means that the cross-sectional shape has corners with greater curvature than other parts, as opposed to a perfect circle, and includes not only cases where the cross-sectional shape is a geometric polygon, but also cases where the cross-sectional shape is defined by multiple corners (portions with relatively greater curvature) and curves with smaller curvature than the corners. In the exemplary embodiment shown in FIG. 4, the cross-sectional shape of prismatic portion 22 of front shaft part 21 has four curves with relatively smaller curvatures and corners defined by the intersections of these four curves.

[0029] The outer cylinder part 31 is sandwiched and held between the front shaft part 21, which is joined to the front end part 54 of the intermediate shaft 50, and the tail plug 40, which is joined to the rear end part 55 of the intermediate shaft 50. In other words, the tail plug 40 has the function of preventing the outer cylinder part 31 from slipping out rearward from the front shaft part 21. Furthermore, by the outer tube part 31 being stretched in the axial direction between the front shaft part 21 and the tail plug 40, the engagement of the first convex part 51 with the bending recess 12B of the first recess 12 and the engagement of the second convex part 52 with the bending recess 42B of the second recess 42 can be made stronger.

[0030] 1 to 3, front barrel part 21 includes a first locking portion 24 adjacent to the front side of rectangular column portion 22, and tail plug 40 includes a second locking portion 44 adjacent to the rear side of front end portion 48 that is inserted into rear end opening 34 of barrel part 31. First locking portion 24 is thicker than rectangular column portion 22, and second locking portion 44 is thicker than front end portion 48. In other words, in front barrel part 21, first locking portion 24 protrudes radially outward from rectangular column portion 22, and in tail plug 40, second locking portion 44 protrudes radially outward from front end portion 48. Therefore, the front end of outer barrel part 31 is locked by first locking portion 24 of front shaft part 21, and the rear end of outer barrel part 31 is locked by second locking portion 44 of tail plug 40. In other words, outer barrel part 31 is clamped between first locking portion 24 of front shaft part 21 and second locking portion 44 of tail plug 40.

[0031] In some embodiments, as shown in Figures 1 and 2, the front barrel part 21, the outer barrel part 31, and the tail plug 40 each have a prismatic shape with corners that coincide with each other at least in the portions that make up the outer surface of the applicator 1. 1 and 2, first locking portion 24 of front barrel part 21, outer barrel part 31, and second locking portion 44 of tail plug 40 are parts that make up the outer surface of applicator 1. Therefore, from the perspective of improving the design of applicator 1 as a whole, first locking portion 24 of front barrel part 21, outer barrel part 31, and second locking portion 44 of tail plug 40 have a rectangular columnar shape with four corners, and the corners of each of the outer shapes are aligned with each other.

[0032] In some embodiments, the applicator 1 includes a cap 60 having a rear end opening 61 into which the front shaft portion 20 fits, as shown in FIGS. Front shaft section 20 has truncated pyramidal portion 26, which has a truncated pyramidal outer shape, forward of first recess 12. Trauncated pyramidal portion 26 constitutes the rear-end portion of the front region of front shaft section 20 that fits into rear-end opening 61 of cap 60. When front shaft section 20 is formed by front shaft part 21 as in the embodiment of Figures 1 to 3, truncated pyramidal portion 26 is provided in front shaft part 21 adjacent to the front side of first locking portion 24. Trauncated pyramidal portion 26 is tapered such that the cross-sectional area gradually decreases toward the front. In contrast, the rear end opening 61 of the cap 60 is prismatic, corresponding to the outer shape of the truncated pyramidal portion 26 of the front shaft portion 20. This makes it easy to insert the cap 60 into the tapered rear end opening 61 of the truncated pyramidal portion 26 of the front shaft portion 20. Furthermore, because the prismatic rear end opening 61 corresponds to the outer shape of the truncated pyramidal portion 26, the cap 60 can be attached to the front shaft portion 20 so that it is immovable in the rotational direction. Although not shown, a small protrusion is provided on the rear end opening 61 of cap 60, and another small protrusion is also provided on the truncated pyramidal portion 26 of front barrel 20. The small protrusions can be locked together by climbing over each other in the axial direction. This is known as cap fitting, and cap 60 can be removably fixed to front barrel 20.

[0033] In the embodiment shown in FIG. 3, the cap 60 includes an outer cap 62 that defines a rear end opening 61 and an inner cap 64 that is provided inside the outer cap 62. Inner cap 64 has a sealing protrusion 66 that continues in the circumferential direction on its inner circumferential surface. In contrast, front barrel portion 20 includes a cylindrical tip portion 28 on the front side of truncated pyramidal portion 26. When cap 60 is attached to front barrel portion 20, tip portion 28 of front barrel portion 20 is inserted into inner cap 64, and sealing protrusion 66 on the inner circumferential surface of inner cap 64 comes into close contact with the outer circumferential surface of tip portion 28. In this way, sealing protrusion 66 of inner cap 64 and tip portion 28 of front barrel portion 20 form a sealed space inside inner cap 64 for accommodating applicator part 2 (pen tip 72), thereby preventing applicator part 2 (pen tip 72) from drying out.

[0034] In some embodiments, as shown in Figures 1 and 2, the cap 60 (outer cap 62), the outer tube portion 30 of the shaft portion 10, and the tail plug 40 (second locking portion 44) each have a rectangular columnar shape with corners that coincide with each other.

[0035] Next, other internal structures of the applicator 1 will be described with reference to FIGS.

[0036] In some embodiments, the front axle part 21 is a two-color molded product (or a composite molded product formed by joining two parts together) including a first resin part 20A made of a first resin and a second resin part 20B made of a second resin different from the first resin.

[0037] In the exemplary embodiment shown in FIGS. 2 and 3 , the first resin portion 20A includes a circular opening 11 and a first recess 12 in the shaft portion 10. Two rows of inner peripheral convex portions 27 are provided on the inner peripheral surface of the first resin portion 20A that defines the opening 11. These two rows of inner peripheral convex portions 27 correspond to two rows of outer peripheral convex portions 56 provided on the outer peripheral surface of the front end portion 54 of the intermediate shaft 50, respectively. That is, when the front end portion 54 of the intermediate shaft 50 is assembled to the front shaft component 21, the two rows of outer peripheral convex portions 56 ride over the corresponding inner peripheral convex portions 27 and stop in a state of contact with the inner peripheral convex portions 27. This prevents ink from leaking from the internal space 4 of the ink tank 3 serving as the intermediate shaft 50 through a gap between the front end portion 54 of the intermediate shaft 50 and the first resin portion 20A of the front shaft component 21. The first resin constituting the first resin portion 20A is not particularly limited, but for example, polypropylene (PP) having appropriate elasticity may be used from the viewpoint of effectively preventing ink leakage by engagement between the outer peripheral convex portion 56 and the inner peripheral convex portion 27. In this case, the intermediate shaft 50 may also be made of polypropylene (PP) having appropriate elasticity.

[0038] 2 and 3, the second resin part 20B includes a first locking part 24 that constitutes part of the outer surface of the applicator 1, and a truncated pyramidal part 26 located in front of the first locking part 24. The first locking part 24 and the truncated pyramidal part 26 have a prismatic outer shape with the positions of the corners coinciding with each other. The second resin constituting the second resin portion 20B is not particularly limited, but for example, from the viewpoint of giving a sense of unity to the prismatic and truncated pyramidal appearances of the first engagement portion 24 and the truncated pyramidal portion 26 and improving the design, it is possible to use a luxurious polycarbonate (PC) or polymethyl methacrylate (PMMA), etc.

[0039] In some embodiments, the applicator 1 includes a nib set 70 that is mounted in front of the ink reservoir 3 as the intermediate shaft 50. As shown in FIGS. 2 and 3 , the nib set 70 is assembled to the ink tank 3 by being inserted into the front-end opening 59 of the ink tank 3. The nib set 70 includes a nib 72 serving as the application part 2, a sleeve 73 that guides the nib 72 axially and functions as an ink absorbing body (buffer member) to prevent ink leakage, a valve element 74 press-fitted to the rear end of the nib 72, a valve seat 76 against which the valve element 74 can seat, a spring 79 that biases the valve element 74 forward, and a valve casing 78 that covers the valve element 74 and the spring 79. The valve casing 78 is inserted into the front-end opening 59 of the ink tank 3. The nib 72 passes through the through-hole 29 in the tip portion 28 of the front barrel part 21, so that the tip of the nib 72 protrudes from the front barrel part 21. The sleeve 73 is housed inside the truncated pyramidal portion 26 of the front barrel part 21. When the force acting rearward from the paper surface on the pen tip 72 is small, the valve body 74 is pressed against the valve seat 76 by the forward biasing force of the spring 79, blocking the ink supply path from the internal space 4 of the ink tank 3 to the pen tip 72. In contrast, when the force acting rearward from the paper surface on the pen tip 72 exceeds the biasing force of the spring 79, the pen tip 72 moves backward while being guided by the sleeve 73, the valve body 74 moves away from the valve seat 76, and the internal space 4 of the ink tank 3 and the space on the pen tip 72 side communicate with each other.

[0040] Fig. 5 is a cross-sectional view of an applicator according to another embodiment, and Fig. 6 is a cross-sectional perspective view of the shaft portion 10 of an applicator according to another embodiment.

[0041] In some embodiments, the shaft portion 10 of the applicator 1 (1B) is an integrally molded product including a front shaft portion 20 and an outer cylinder portion 30, as shown in FIG. The stem 10 includes a prismatic section 14 formed by the rear end of the front stem 20 and the outer tube 30. The prismatic section 14 of the stem 10 has a prismatic outer shape whose corners coincide with those of the cap 60 (outer cap 62) and the tail plug 40 (second locking section 44). 6, the front shaft portion 20 has an L-shaped first recessed groove 18 as the first recessed portion 12. As described above, the first recessed portion 12 (first recessed groove 18) includes an axial recessed portion 12A extending along the axial direction of the applicator 1 (1B), and a bent recessed portion 12B that is bent from the innermost portion of the axial recessed portion 12A in a direction perpendicular to the axial direction.

[0042] The characteristic configurations of the applicators 1 (1A, 1B) according to the above-described embodiments can be summarized as follows.

[0043] [1] The applicator 1 (1A, 1B) according to at least some embodiments of the present invention is a shaft portion (10) having an L-shaped first recess (12) that opens to the rear side; a tail plug (40) having an L-shaped second recess (42) that opens to the front side; an intermediate shaft (50) including a front end (54) having a first protrusion (51) on its outer circumferential surface that engages with the first recess (12), and coupled to the shaft portion (10) by the engagement between the first recess (12) and the first protrusion (51); and a rear end (55) having a second protrusion (52) on its outer circumferential surface that engages with the second recess (42), and coupled to the tail plug (40) by the engagement between the second recess (42) and the second protrusion (52); Equipped with.

[0044] According to the configuration [1] above, the first convex portion (51) provided at the front end portion (54) of the intermediate shaft (50) is engaged with the L-shaped first concave portion (12) of the shaft portion (10), and the second convex portion (52) provided at the rear end portion (55) of the intermediate shaft (50) is engaged with the L-shaped second concave portion (42) of the tail plug (40), thereby enabling highly accurate circumferential alignment of the shaft portion (10) and the tail plug (40).

[0045] [2] In some embodiments, in the configuration of [1] above, The shaft portion (10) a front shaft portion (20) located in front of the intermediate shaft (50) and having a first recess (12) at its rear end; an outer cylinder portion (30) that covers a first recess (12) at the rear end of the front shaft portion (20) and the intermediate shaft (50); Includes.

[0046] According to the configuration [2] above, the outer cylinder portion (30) covers the first recess (12) of the front shaft portion (20) and the intermediate shaft (50), thereby improving the design of the applicator (1; 1A, 1B) as a whole.

[0047] [3] In some embodiments, in the configuration of [2] above, The outer cylindrical portion (30) covers the second recess (42) of the tail plug (40).

[0048] According to the configuration [3] above, the outer cylinder portion (30) covers not only the first recess (12) of the front shaft portion (20) and the intermediate shaft (50), but also the second recess (42) of the tail plug (40), thereby further improving the design of the applicator (1; 1A, 1B) as a whole.

[0049] [4] In some embodiments, in the configuration of [2] or [3] above, The front shaft portion (20) is formed by a front shaft part (21) having an L-shaped first slit (16) as a first recess (12) at its rear end, The outer cylindrical portion (30) is detachably attached to the front shaft part (21) and is formed by the outer cylindrical part (31) having a front end opening (32) into which the rear end of the front shaft part (21) is fitted.

[0050] According to the configuration [4] above, the shaft portion 10 is formed of multiple parts, including the front shaft part 21 and the outer cylinder part 31, which facilitates molding of the shaft portion 10. Furthermore, if the intermediate shaft 50 is assembled to the front shaft part 21 with the outer cylinder part 31 removed from the front shaft part 21, the visibility of the first recessed part 12 and the first protruding part 51 is improved, which facilitates the assembly work.

[0051] [5] In some embodiments, in the configuration of [4] above, The rear end of the front shaft part (21) is prismatic, The front end opening (32) of the outer barrel part (31) has an angular shape that is complementary to the rear end of the front shaft part (21).

[0052] According to the configuration [5] above, the outer tube part (31) can be attached to the front shaft part (21) so that it cannot rotate circumferentially, and the outer tube part (31) can be aligned circumferentially with respect to the front shaft part (21) with high precision.

[0053] [6] In some embodiments, in the configuration of [4] or [5] above, The outer cylinder part (31) is sandwiched and held between the front shaft part (21) connected to the front end part (54) of the intermediate shaft (50) and the tail plug (40) connected to the rear end part (55) of the intermediate shaft (50). The tail plug 40 may be made of a thermoplastic elastomer having a suitable elasticity, which reduces axial dimensional variations of the intermediate shaft 50.

[0054] According to the configuration [6] above, the outer cylinder part (31) is sandwiched and held between the front shaft part (21) and the tail plug (40), so that the outer cylinder part (31) can be prevented from slipping out in the axial direction while maintaining ease of attachment and detachment of the outer cylinder part (31).

[0055] [7] In some embodiments, in any of the configurations [4] to [6] above, The front barrel part (21), the outer barrel part (31), and the tail plug (40) each have a prismatic shape with corners that coincide with each other at least in the portions that form the outer surface of the applicator (1A).

[0056] According to the configuration [7] above, the front shaft part (21), the outer cylinder part (31), and the tail plug (40) that constitute the outer surface of the applicator (1A) each have a rectangular columnar shape, and the corners of each of the outer shapes match each other, thereby improving the design of the applicator (1A) as a whole. For the reason described in [1] above, the front shaft part (21) and the tail plug (40) can be aligned in the circumferential direction with high precision. Therefore, the positions of the corners of the outer shapes of each part of the applicator (1A), including the front shaft part (21) and the tail plug (40), which are positioned axially apart, match with high precision, which contributes to improving the design of the applicator (1A).

[0057] [8] In some embodiments, in any of the configurations [2] to [7] above, The applicator (1; 1A, 1B) is The cap (60) has a rear end opening (61) into which the front shaft portion (20) of the shaft portion (10) is fitted, The front shaft portion (20) has a truncated pyramidal shape in front of the first recess (12), The rear end opening (61) of the cap (60) is prismatic in shape, corresponding to the truncated pyramidal outer shape of the front shaft portion (20).

[0058] According to the configuration [8] above, the cap (60) can be attached to the front shaft portion (20) so that it cannot rotate circumferentially, and the cap (60) can be aligned circumferentially with respect to the front shaft portion (20) with high precision.

[0059] [9] In some embodiments, in the configuration of [8] above, The cap (60), the outer cylindrical portion (30) of the stem (10), and the tail plug (40) each have a prismatic shape with the corners aligned with one another.

[0060] According to the configuration [9] above, the cap (60), the outer tubular portion (30), and the tail plug (40) each have a rectangular columnar shape, and the corners of the respective shapes coincide with each other, thereby improving the design of the applicator (1; 1A, 1B) as a whole. The front shaft portion (20) and the tail plug (40) can be aligned circumferentially with high precision for the reasons described in [1] above. The front shaft portion (20) and the cap (60) can be aligned circumferentially with high precision for the reasons described in [8] above. Therefore, the positions of the corners of the outer shapes of each part of the applicator (1; 1A, 1B) match with high precision, including the cap (60), front shaft portion (20), and tail plug (40), which are positioned axially apart, which contributes to improving the design of the applicator (1; 1A, 1B).

[0061]

[10] In some embodiments, in any of the configurations [2], [3], [8], or [9] above, The shaft portion (10) is an integrally molded product including a front shaft portion (20) and an outer cylinder portion (30), The front shaft portion (20) of the shaft portion (10) has an L-shaped first recessed groove (18) as the first recess (12).

[0062] According to the configuration

[10] above, the shaft portion (10) is formed from an integrally molded product including the front shaft portion (20) and the outer cylinder portion (30), thereby making it possible to reduce the manufacturing cost of the applicator (1B) by reducing the number of parts while enjoying the technical benefits of [1] above.

[0063] The applicator 1 according to the embodiment has been described above, but appropriate modifications may be made without departing from the spirit of the present invention. For example, Figures 1 and 2 show an example of an applicator 1 in which the outer shapes of multiple axially separated parts (21, 31, 40, 60) are rectangular columns and the corners of these parts are aligned, but the present invention can also be applied to applicators in which the patterns of multiple axially separated parts are aligned circumferentially. [Explanation of symbols]

[0064] 1 (1A, 1B): Applicator 10: Shaft 11:Aperture 12: First recess 16: First slit 18: 1st concave groove 20: Front shaft 21: Front axle parts 30: Outer cylinder 31: Outer cylinder part 32: Front end opening 34: Rear end opening 40: tail plug 41 :Aperture 42: Second recess 46: Slit 48: Front end 50: Intermediate shaft 51: First convex part 52: Second convex part 54: Front end 55: Rear end 59: Front end opening 60: Cap 61: Rear end opening

Claims

1. a shaft portion having an L-shaped first recess portion that opens to the rear side; a tail plug having an L-shaped second recess that opens to the front side; an intermediate shaft including a front end portion having a first protrusion on an outer peripheral surface thereof that engages with the first recess, and coupled to the shaft portion through engagement between the first protrusion and the first recess; and a rear end portion having a second protrusion on an outer peripheral surface thereof that engages with the second recess, and coupled to the tail plug through engagement between the second protrusion and the second recess; An applicator comprising:

2. The shaft portion is a front shaft portion located in front of the intermediate shaft and having the first recess at a rear end thereof; an outer cylinder portion that covers the first recess at the rear end of the front shaft portion and the intermediate shaft; Contains The applicator according to claim 1 .

3. The outer cylindrical portion covers the second recess of the tail plug. The applicator according to claim 2.

4. the front shaft portion is formed by a front shaft part having an L-shaped first slit as the first recess at a rear end thereof, The outer cylindrical portion is detachable from the front shaft part and is formed by an outer cylindrical part having a front end opening into which the rear end of the front shaft part is fitted. The applicator according to claim 2 or 3.

5. The rear end of the front shaft component is prismatic, The front end opening of the outer barrel part has an angular shape complementary to the rear end of the front shaft part. The applicator according to claim 4.

6. The outer cylinder part is sandwiched and held between the front shaft part connected to the front end part of the intermediate shaft and the tail plug connected to the rear end part of the intermediate shaft. The applicator according to claim 4.

7. The front barrel part, the outer barrel part, and the tail plug each have a prismatic shape with corners that are aligned with each other at least in the portions that form the outer surface of the applicator. The applicator according to claim 4.

8. a cap having a rear end opening into which the front shaft portion of the shaft portion is fitted, The front shaft portion has a truncated pyramidal shape forward of the first recess, The rear end opening of the cap has a prismatic shape corresponding to the truncated pyramidal shape of the front shaft portion. The applicator according to claim 2 or 3.

9. The cap, the outer cylindrical portion of the barrel, and the tail plug each have a prismatic shape with corners that coincide with each other. The applicator according to claim 8.

10. the shaft portion is an integrally molded product including the front shaft portion and the outer cylinder portion, The front shaft portion of the shaft portion has an L-shaped first groove as the first recess. The applicator according to claim 2 or 3.

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