Ballpoint pen tip and method for manufacturing the ballpoint pen tip.

Abstract

To provide a ball point pen tip formed in a shape which is not a simple rotor considering mainly designability.SOLUTION: The ball point pen tip including a cylindrical part, a holder constituting a tip side of the cylindrical part and having a diametrically contracting part gradually reduced in an outer diameter to the tip, a writing ball held at the tip of the diametrically contracting part, and a recess part where a part of the diametrically contracting part is recessed.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a ballpoint pen tip and a method for manufacturing the same. [Background technology]

[0002] Ballpoint pen tips manufactured by cutting a cylindrical material made of stainless steel usually have a tapered, approximately conical shape at the tip. Patent Document 1 below discloses a ballpoint pen tip with a concave curved side at the tapered tip, which makes the lines drawn by the pen tip easier to see and also takes design into consideration. There have also been attempts to form a part with fine irregularities on the conical surface of a ball holder and color this part by painting (Patent Document 2 below). Furthermore, a technology has been disclosed in which identification information such as letters is added to the surface of a ballpoint pen tip by laser engraving (Patent Document 3 below).

[0003] A technique has also been disclosed in which an air vent groove is provided along the longitudinal direction around the periphery of the shaft of the pen tip body of a ballpoint pen (Patent Document 4 listed below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-13426 A [Patent Document 2] JP 2009-34874 A [Patent Document 3] JP 2010-155426 A [Patent Document 4] Special Publication No. 2006-509657 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned conventional techniques, the outer diameter of the ballpoint pen tip is formed as a body of revolution around the axis as a whole. The present invention aims to form the tip portion of the ballpoint pen tip into a shape that is not a simple body of revolution, mainly taking into consideration design. [Means for solving the problem]

[0006] The ballpoint pen tip of an embodiment of the present disclosure is characterized in comprising a holder having a cylindrical portion and a tapered portion constituting the tip side of the cylindrical portion and having an outer diameter that gradually decreases toward the tip, a writing ball held at the tip of the tapered portion, and a recess in which a portion of the outer surface of the tapered portion is recessed.

[0007] Here, as for the aforementioned reduced diameter portion, so long as the diameter decreases from the cylindrical portion to the writing ball, there may be a portion in the middle where the diameter is constant.

[0008] In addition, in the ballpoint pen tip of the embodiment of the present disclosure, it is preferable that a plurality of the recesses are provided in consideration of design. Furthermore, in this case, it is preferable that the recesses are equally distributed in the circumferential direction in consideration of the fact that a load is symmetrically applied to the ballpoint pen tip in the manufacturing process.

[0009] In the ballpoint pen tip of the embodiment of the present disclosure, the recess may be colored. By coloring the recess, it is possible to display the color of the ink contained in the ballpoint pen refill to which the ballpoint pen tip is attached.

[0010] The ballpoint pen tip of the embodiment of the present disclosure can be manufactured by cutting a part of the outer surface of the tapered portion of the ballpoint pen tip, the part being recessed, to form a recess. The ballpoint pen tip includes a holder having a cylindrical portion, a tapered portion that constitutes the tip side of the cylindrical portion and has an outer shape that gradually decreases toward the tip, and a writing ball that is held at the tip of the tapered portion. In this case, the cutting is preferably performed by broaching. Effect of the Invention

[0011] Since the embodiment of the present application is configured as described above, it is possible to form the tip portion of the ballpoint pen tip into a shape that is not a simple body of revolution, mainly taking into consideration design. [Brief description of the drawings]

[0012] [Figure 1] 3 shows the processing steps for a ballpoint pen tip according to the first manufacturing method. [Diagram 2] 4 shows the processing steps for a ballpoint pen tip according to the second manufacturing method. [Diagram 3] 4 shows the processing steps for a ballpoint pen tip according to the third manufacturing method. [Figure 4] 11 shows the processing steps for a ballpoint pen tip according to the fourth manufacturing method. [Diagram 5] 1A is a front perspective view, (B) a rear perspective view, (C) a front view, (D) an intermediate view between the front view and the side view, (E) and (F) a bottom view of a ballpoint pen tip of a first embodiment. [Figure 6] FIG. 1 shows a front view (A), an enlarged plan view (B), an enlarged bottom view (C), an enlarged front view (D) of the tip portion, and an enlarged front oblique view (E) of the tip portion of a ballpoint pen refill equipped with a ballpoint pen tip of the first embodiment. [Figure 7] 1A is a front view of a ballpoint pen refill equipped with a ballpoint pen tip of a second embodiment, (B) an enlarged plan view, (C) an enlarged front view of the tip portion, (D) and (E) an enlarged front oblique view of the tip portion. [Figure 8] 1A is a front view of a ballpoint pen refill equipped with a ballpoint pen tip of a third embodiment, (B) an enlarged plan view, (C) an enlarged front view of the tip portion, (D) and (E) an enlarged front oblique view of the tip portion. [Figure 9] 1A is a front view of a ballpoint pen refill equipped with a ballpoint pen tip of a fourth embodiment, (B) an enlarged plan view, (C) an enlarged front view of the tip portion, (D) and (E) an enlarged front oblique view of the tip portion. [Figure 10]13A is a front view of a ballpoint pen refill equipped with a ballpoint pen tip of a fifth embodiment, (B) an enlarged plan view, (C) an enlarged front view of the tip portion, (D) and (E) an enlarged front oblique view of the tip portion. [Figure 11] 13A is a front view of a ballpoint pen refill equipped with a ballpoint pen tip of a sixth embodiment, (B) an enlarged plan view, (C) an enlarged front view of the tip portion, (D) and (E) an enlarged front oblique view of the tip portion. [Figure 12] FIG. 13 is a front view (A), an enlarged plan view (B), an enlarged bottom view (C), an enlarged front view (D) of the tip portion, and an enlarged front oblique view (E) of the tip portion of a ballpoint pen refill equipped with a ballpoint pen tip of a seventh embodiment. [Figure 13] 13A is a front view of a ballpoint pen refill equipped with a ballpoint pen tip of an eighth embodiment, (B) an enlarged plan view, (C) an enlarged front view of the tip portion, (D) and (E) an enlarged front oblique view of the tip portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The embodiments of the present application will be described with reference to the drawings. In the following description with reference to the drawings, a view drawn from the front end side of the ballpoint pen tip or ballpoint pen refill is referred to as a plan view, and a view drawn from the opposite side is referred to as a bottom view. Furthermore, the same reference numerals in each drawing indicate the same configuration without any particular explanation.

[0014] (1) Manufacturing method (1-1) First manufacturing method FIG. 1 is a schematic diagram showing a first manufacturing method of the ballpoint pen tip of this embodiment. FIG. 1(A) shows a front view of the ballpoint pen tip 10 before the recess 24 is formed. The ballpoint pen tip 10 includes a holder 20 formed by cutting a cylindrical metal material, and a writing ball 30 held at the tip of the holder 20. The holder 20 includes a cylindrical cylindrical portion 21 having a maximum outer diameter, a tapered diameter reduced portion 22 in which the tip side of the cylindrical portion 21 is tapered, and an insertion portion 26 in which the rear end side of the cylindrical portion 21 is cylindrically reduced in diameter. In addition, the periphery of the writing ball 30 held at the tip of the reduced diameter portion 22 is a crimped portion 23 that is crimped inward.

[0015] Broach tool 50, which is a tool for forming recesses 24 in reduced diameter portion 22, has a shape as shown in the front view of Fig. 1(B) and the bottom view of Fig. 1(C). Broach tool 50 has a cylindrical shape as a whole, but the bottom end is divided into four, each of which serves as a blade 51 for cutting recesses 24. In other words, the four blades 51 are equally spaced about the axis (see Fig. 1C).

[0016] With the ballpoint pen tip 10 of FIG. 1(A) fixed at a predetermined position on the production line with the tip facing upward, a broach tool 50 whose axis is aligned with that of the ballpoint pen tip 10 is brought close from above, and a portion of the outer surface on the tip side of the reduced diameter portion 22 is cut so as to be recessed with a blade 51 (see FIG. 1(D)).

[0017] The ballpoint pen tip 10 after broaching in FIG. 1(D) has a shape as shown in the front view of FIG. 1(E) and the plan view of FIG. 1(F). The cylindrical portion 21, the insertion portion 26, the crimped portion 23, and the writing ball 30 of the holder 20 are the same as those shown in FIG. 1(A), but the outer peripheral surface of the reduced diameter portion 22 has four equally spaced recesses 24 centered on the axis. Each recess 24 is recessed so that three surfaces are exposed: a bottom surface (see FIG. 1(F)) that is fan-shaped in plan view, and two side surfaces (see FIG. 1(E)) that are congruent right-angled triangles. As shown in the front view of FIG. 1(G) and the plan view of FIG. 1(H), the recess 24 can also have a colored portion 25 that is colored by applying a paint of a predetermined color.

[0018] (1-2) Second manufacturing method Fig. 2 is a schematic diagram showing a second manufacturing method of the ballpoint pen tip of this embodiment. In the second manufacturing method, the ballpoint pen tip 10 in the state shown in Fig. 1 (E) and (F) is fixed with the tip facing upward at the same predetermined position on the manufacturing line, and the broach tool 50 shown in Fig. 1 (B) and (C) is again approached from above in a state rotated 45°, and the outer surface without the recess 24 on the tip side of the reduced diameter part 22 is cut so as to be recessed with the blade 51 (see Fig. 2 (A)).

[0019] The ballpoint pen tip 10 after broaching in FIG. 2(A) has a shape as shown in the front view and the plan view of FIG. 2(C). The cylindrical portion 21, the insertion portion 26, the crimped portion 23, and the writing ball 30 of the holder 20 are the same as those shown in FIG. 1(A), but the outer peripheral surface of the reduced diameter portion 22 has eight equally spaced recesses 24 centered on the axis. Each recess 24 is recessed so that three surfaces are exposed: a bottom surface (see FIG. 2(C)) that is fan-shaped in plan view, and two side surfaces (see FIG. 2(B)) that are congruent right-angled triangles. As shown in the front view of FIG. 2(D) and the plan view of FIG. 2(E), the recess 24 can also be colored by applying a paint of a predetermined color to form a colored portion 25.

[0020] (1-3) Third manufacturing method 3 is a schematic diagram showing a third manufacturing method of the ballpoint pen tip of this embodiment. FIG. 3(A) shows a front view of the ballpoint pen tip 10 before the recess 24 is formed. The ballpoint pen tip 10 includes a holder 20 formed by cutting a cylindrical metal material, and a writing ball 30 held at the tip of the holder 20. The holder 20 includes a cylindrical cylindrical portion 21 having a maximum outer diameter, a tapered diameter-reduced portion 22 at the tip side of the cylindrical portion 21, and an insertion portion 26 at the rear end side of the cylindrical portion 21 having a cylindrical diameter-reduced shape. In addition, the periphery of the writing ball 30 held at the tip of the reduced diameter portion 22 is a crimped portion 23 crimped inward.

[0021] Broach tool 50, which is a tool for forming recesses 24 in reduced diameter portion 22, has a shape as shown in the front view of Fig. 3(B) and the bottom view of Fig. 3(C). Broach tool 50 has a cylindrical shape as a whole, but the bottom end is divided into three, each of which serves as a blade 51 for cutting recesses 24. In other words, the three blades 51 are equally spaced about the axis (see Fig. 1C).

[0022] With the ballpoint pen tip 10 of Figure 3 (A) fixed at a predetermined position on the production line with the tip facing upward, a broach tool 50 whose axis is aligned with the ballpoint pen tip 10 is brought close from above and a part of the outer surface on the tip side of the reduced diameter portion 22 is cut so as to be recessed with a blade 51 (see Figure 3 (D)).

[0023] The ballpoint pen tip 10 after broaching in FIG. 3(D) has a shape as shown in the front view of FIG. 3(E) and the plan view of FIG. 3(F). The cylindrical portion 21, the insertion portion 26, the crimped portion 23, and the writing ball 30 of the holder 20 are the same as those shown in FIG. 3(A), but the outer peripheral surface of the reduced diameter portion 22 has three equally spaced recesses 24 centered on the axis. Each recess 24 is recessed so that three surfaces are exposed: a bottom surface (see FIG. 3(F)) that is fan-shaped in plan view, and two side surfaces (see FIG. 3(E)) that are congruent right-angled triangles. As shown in the front view of FIG. 3(G) and the plan view of FIG. 3(H), the recess 24 can also be colored by applying a paint of a predetermined color to form a colored portion 25.

[0024] (1-4) Fourth manufacturing method Fig. 4 is a schematic diagram showing a fourth manufacturing method of the ballpoint pen tip of this embodiment. In the fourth manufacturing method, the ballpoint pen tip 10 in the state shown in Fig. 3(E) and (F) is fixed with the tip facing upward at the same predetermined position on the manufacturing line, and the broach tool 50 shown in Fig. 3(B) and (C) is again approached from above in a rotated state of 60°, and the outer surface without the recess 24 on the tip side of the reduced diameter part 22 is cut so as to be recessed by the blade 51 (see Fig. 4(A)).

[0025] The ballpoint pen tip 10 after broaching in FIG. 4(A) has a shape as shown in the front view of FIG. 4(B) and the plan view of FIG. 4(C). The cylindrical portion 21, the insertion portion 26, the crimped portion 23, and the writing ball 30 of the holder 20 are the same as those shown in FIG. 3(A), but the outer peripheral surface of the reduced diameter portion 22 has six equally spaced recesses 24 centered on the axis. Each recess 24 is recessed so that three surfaces are exposed: a bottom surface (see FIG. 4(C)) that is fan-shaped in plan view, and two side surfaces (see FIG. 4(B)) that are congruent right-angled triangles. As shown in the front view of FIG. 4(D) and the plan view of FIG. 4(E), the recess 24 can also have a colored portion 25 that is colored by applying a paint of a predetermined color.

[0026] (1-5)Other As described above, the manufacturing method of the ballpoint pen tip of the embodiment of the present application can be carried out by applying a conventional manufacturing line and adding a broaching process. Also, the blades 51 of the broaching tool 50 may be arranged asymmetrically with respect to the axis, but in order to equalize the load on the ballpoint pen tip 10 during broaching, it is preferable that the blades 51 of the broaching tool 50 are arranged evenly with respect to the axis as in the first to fourth manufacturing methods described above.

[0027] The colored portion 25 shown in Figures 1(G) and (H), 2(D) and (E), 3(G) and (H), and 4(D) and (E) can also be colored to correspond to the color of ink contained in the ink containing tube 41 of the ballpoint pen refill 40 to which the ballpoint pen tip 10 is attached. In this way, since the colored portion 25 is in a state where paint is contained in the recess 24, it will not peel off due to rubbing when the ballpoint pen is knocked.

[0028] In addition, depending on the arrangement and number of the recesses 24 or colored portions 25 shown in Figures 1(E) and (F), Figures 2(B) and (C), Figures 3(E) and (F), and Figures 4(B) and (C), it is also possible to use an identifier that corresponds to the attributes of the ink, such as whether it is a water-based ink, an oil-based ink, or a thermochromic ink, or even the color of the ink.

[0029] (2) 10 ballpoint pen tips and 40 ballpoint pen refills (2-1) First embodiment The ballpoint pen tip 10 of the first embodiment is shown in a front oblique view in FIG. 5(A), a rear oblique view in FIG. 5(B), a front view in FIG. 5(C), an intermediate view between the front view and the side view in FIG. 5(D), a plan view in FIG. 5(E), and a bottom view in FIG. 5(F).

[0030] The ballpoint pen tip 10 includes a holder 20 formed by cutting a cylindrical metal material, and a writing ball 30 held at the tip of the holder 20 (see Figs. 1(A)-(E)). The holder 20 includes a cylindrical portion 21 having a maximum outer diameter, a tapered portion 22 that constitutes the tip side of the cylindrical portion 21 and gradually reduces in diameter toward the tip, a plurality of recesses 24, specifically four recesses 24, formed by partially recessing the outer surface of the tapered portion 22, and an insertion portion 26 having a cylindrically reduced diameter at the rear end side of the cylindrical portion 21 (see Figs. 1(A)-(D)). A back hole 27 opens at the rear end of the insertion portion 26 (see Figs. 1(B) and (F)). The periphery of the writing ball 30 held at the tip of the tapered portion 22 is a crimped portion 23 that is crimped inward (see Figs. 1(A)-(E)). The recesses 24 are formed as shown in the first manufacturing method. The four recesses 24 are equally spaced in the circumferential direction about the axis (see FIG. 1(E)). Each of the recesses 24 is recessed so that three faces are exposed: a bottom face (see FIG. 5(E)) that is sector-shaped in a plan view, and two side faces (see FIGS. 5(A) to (D)) that are congruent right-angled triangles.

[0031] The ballpoint pen refill 40 with the ballpoint pen tip 10 of the first embodiment attached is shown in a front view in FIG. 6(A), an enlarged plan view in FIG. 6(B), an enlarged bottom view in FIG. 6(C), an enlarged front view of the tip portion in FIG. 6(D), and an enlarged front perspective view of the tip portion in FIG. 6(E). The ballpoint pen refill 40 is formed by pressing the insertion portion 26 (see FIGS. 5(A)-(D)) of the ballpoint pen tip 10 into the tip of a cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical portion 21 of the ballpoint pen tip (see FIGS. 6(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 6(C)).

[0032] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the tapered portion 22 that constitutes the tip side of the cylindrical portion 21 is tapered, and the outer diameter gradually decreases toward the tip. A part of the outer surface of the tapered portion 22 is recessed into four recesses 24. The periphery of the writing ball 30 that is held at the tip of the tapered portion 22 is a crimped portion 23 that is crimped inward (see Figs. 6(B), (D) and (E)). The recesses 24 are formed as shown in the first manufacturing method. The four recesses 24 are equally spaced in the circumferential direction with respect to the axis (see Fig. 6(B)). Each of the recesses 24 is recessed so that three faces are exposed: a bottom face that is fan-shaped in a plan view (see Fig. 5(E)) and two side faces that are congruent right-angled triangles (see Fig. 6(E)).

[0033] In addition, when the ballpoint pen refill 40 in the state shown in Figure 6 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0034] (2-2) Second embodiment The ballpoint pen refill 40 with the ballpoint pen tip 10 of the second embodiment attached is shown in a front view of FIG. 7(A), an enlarged plan view of FIG. 7(B), an enlarged bottom view of FIG. 7(C), an enlarged front view of the tip portion of FIG. 7(D), and an enlarged front perspective view of the tip portion of FIG. 7(E). The ballpoint pen refill 40 is formed by pressing the insertion part 26 (see FIG. 5(A)-(D)) of the ballpoint pen tip 10 (not shown) into the tip of the cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical part 21 of the ballpoint pen tip 10 (see FIG. 6(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 7(C)).

[0035] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the tapered portion 22 that constitutes the tip side of the cylindrical portion 21 is tapered, and the outer diameter gradually decreases toward the tip. A part of the outer surface of the tapered portion 22 is recessed into four recesses 24. The periphery of the writing ball 30 that is held at the tip of the tapered portion 22 is a crimped portion 23 that is crimped inward (see Figures 7(B), (D) and (E)). The recesses 24 are formed as shown in the first manufacturing method. However, in this embodiment, the rear end edge of the recesses 24 stops further forward than in the first embodiment. The four recesses 24 are equally spaced in the circumferential direction with respect to the axis (see Figure 7(B)). Each of the recesses 24 is recessed so that three faces are exposed: a bottom face (see FIG. 7(E)) that is sector-shaped in a plan view, and two side faces (see FIG. 7(E)) that are congruent right-angled triangles.

[0036] In addition, when the ballpoint pen refill 40 in the state shown in Figure 7 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0037] (2-3) Third embodiment The ballpoint pen refill 40 with the ballpoint pen tip 10 of the third embodiment attached is shown in a front view of FIG. 8(A), an enlarged plan view of FIG. 8(B), an enlarged bottom view of FIG. 8(C), an enlarged front view of the tip portion of FIG. 8(D), and an enlarged front perspective view of the tip portion of FIG. 8(E). The ballpoint pen refill 40 is formed by pressing the insertion part 26 (see FIG. 5(A)-(D)) of the ballpoint pen tip 10 (not shown) into the tip of the cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical part 21 of the ballpoint pen tip 10 (see FIG. 8(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 8(C)).

[0038] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the tapered portion 22 that constitutes the tip side of the cylindrical portion 21 is tapered, and the outer diameter gradually decreases toward the tip. A part of the outer surface of the tapered portion 22 is recessed into eight recesses 24. The periphery of the writing ball 30 that is held at the tip of the tapered portion 22 is a crimped portion 23 that is crimped inward (see Figs. 8(B), (D) and (E)). The recesses 24 are formed as shown in the second manufacturing method. The eight recesses 24 are equally spaced in the circumferential direction with respect to the axis (see Fig. 8(B)). Each of the recesses 24 is recessed so that three faces are exposed: a bottom face that is approximately fan-shaped in a plan view (see Fig. 8(E)) and two side faces that are congruent right-angled triangles (see Fig. 8(E)).

[0039] In addition, when the ballpoint pen refill 40 in the state shown in Figure 8 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0040] (2-4) Fourth embodiment A ballpoint pen refill 40 with a ballpoint pen tip 10 of the fourth embodiment attached thereto is shown in a front view in FIG. 9(A), an enlarged plan view in FIG. 9(B), an enlarged bottom view in FIG. 9(C), an enlarged front view of the tip portion in FIG. 9(D), and an enlarged front perspective view of the tip portion in FIG. 9(E). The ballpoint pen refill 40 is formed by pressing the insertion portion 26 (see FIG. 5(A)-(D)) of the ballpoint pen tip 10 (not shown) into the tip of a cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical portion 21 of the ballpoint pen tip (see FIG. 9(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 9(C)).

[0041] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the tapered portion 22 that constitutes the tip side of the cylindrical portion 21 is tapered, and the outer diameter gradually decreases toward the tip. Part of the outer surface of the tapered portion 22 is recessed into eight recesses 24. The periphery of the writing ball 30 that is held at the tip of the tapered portion 22 is a crimped portion 23 that is crimped inward (see Figs. 9(B), (D) and (E)). The recesses 24 are formed as shown in the second manufacturing method. However, the second broaching process remains at a position closer to the tip side than the first broaching process. As a result, the eight recesses 24 are alternately arranged with four recesses located closer to the rear end and equally spaced in the circumferential direction with respect to the axis, and four recesses located closer to the tip and equally spaced in the circumferential direction with respect to the axis (see Fig. 9(B)). Each of the recesses 24 is recessed so that three surfaces are exposed: a bottom surface (see FIG. 9(E)) that is approximately sector-shaped in plan view, and two side surfaces (see FIG. 9(E)) that are congruent right-angled triangles.

[0042] In addition, when the ballpoint pen refill 40 in the state shown in Figure 9 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0043] (2-5) Fifth embodiment The ballpoint pen refill 40 with the ballpoint pen tip 10 of the fifth embodiment attached is shown in a front view of FIG. 10(A), an enlarged plan view of FIG. 10(B), an enlarged bottom view of FIG. 10(C), an enlarged front view of the tip portion of FIG. 10(D), and an enlarged front perspective view of the tip portion of FIG. 10(E). The ballpoint pen refill 40 is formed by pressing the insertion part 26 (see FIG. 5(A)-(D)) of the ballpoint pen tip 10 (not shown) into the tip of the cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical part 21 of the ballpoint pen tip (see FIG. 10(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 10(C)).

[0044] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the narrowed portion 22 that constitutes the tip side of the cylindrical portion 21 first narrows in diameter in a tapered manner, then has the same outer shape toward the tip, and further narrows in diameter toward the tip. A part of the outer surface of the narrowed portion 22 is recessed into four recesses 24. The periphery of the writing ball 30 that is held at the tip of the narrowed portion 22 is crimped inward to form a crimped portion 23 (see Figures 10(B), (D) and (E)). The recesses 24 are formed as shown in the first manufacturing method. The four recesses 24 are equally spaced in the circumferential direction with respect to the axis (see Figure 10(B)). Each of the recesses 24 has a bottom surface (see Figure 10(E)) that is approximately fan-shaped when viewed in a plane, and is formed by a portion at the rear end having two side surfaces that are congruent right-angled triangles (see Figure 10(E)), followed by a groove-shaped portion.

[0045] In addition, when the ballpoint pen refill 40 in the state shown in Figure 10 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0046] (2-6) Sixth embodiment A ballpoint pen refill 40 with a ballpoint pen tip 10 of the sixth embodiment attached thereto is shown in a front view in FIG. 11(A), an enlarged plan view in FIG. 11(B), an enlarged bottom view in FIG. 11(C), an enlarged front view of the tip portion in FIG. 11(D), and an enlarged front perspective view of the tip portion in FIG. 11(E). The ballpoint pen refill 40 is formed by pressing the insertion portion 26 (see FIG. 5(A)-(D)) of the ballpoint pen tip 10 (not shown) into the tip of a cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical portion 21 of the ballpoint pen tip (see FIG. 11(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 11(C)).

[0047] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the reduced diameter portion 22 constituting the tip side of the cylindrical portion 21 is reduced in diameter in a concave curved shape, and the outer diameter gradually decreases toward the tip. Part of the outer surface of the reduced diameter portion 22 is recessed into eight recesses 24. The periphery of the writing ball 30 held at the tip of the reduced diameter portion 22 is a crimped portion 23 that is crimped inward (see Figs. 11(B), (D) and (E)). The recesses 24 are formed as shown in the second manufacturing method. However, the second broaching process remains at a position closer to the tip side than the first broaching process. As a result, the eight recesses 24 are alternately arranged with four recesses located closer to the rear end and equally spaced in the circumferential direction with respect to the axis, and four recesses located closer to the tip and equally spaced in the circumferential direction with respect to the axis (see Fig. 11(B)). Each of the recesses 24 is recessed so that three sides are exposed: a bottom surface (see Figure 11(E)) that is approximately fan-shaped when viewed in a plane, and two side surfaces (see Figure 11(E)) that form congruent right-angled triangles with their hypotenuses curved so as to be recessed.

[0048] In addition, when the ballpoint pen refill 40 in the state shown in Figure 11 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0049] (2-7) Seventh embodiment The ballpoint pen refill 40 with the ballpoint pen tip 10 of the seventh embodiment attached is shown in a front view of Fig. 12(A), an enlarged plan view of Fig. 12(B), an enlarged bottom view of Fig. 12(C), an enlarged front view of the tip portion of Fig. 12(D), and an enlarged front perspective view of the tip portion of Fig. 12(E). The ballpoint pen refill 40 is formed by pressing the insertion part 26 (see Figs. 5(A) to (D)) of the ballpoint pen tip 10 (not shown) into the tip of a cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical part 21 of the ballpoint pen tip (see Figs. 12(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see Fig. 12(C)).

[0050] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the reduced diameter portion 22 constituting the tip side of the cylindrical portion 21 is reduced in diameter in a concave curved shape, and the outer diameter gradually decreases toward the tip. A part of the outer surface of the reduced diameter portion 22 is recessed into eight recesses 24. The periphery of the writing ball 30 held at the tip of the reduced diameter portion 22 is a crimped portion 23 that is crimped inward (see Figs. 12(B), (D) and (E)). The recesses 24 are formed as shown in the second manufacturing method. The eight recesses 24 are equally spaced in the circumferential direction with respect to the axis (see Fig. 12(B)). Each of the recesses 24 is recessed so that three faces are exposed: a bottom face (see Fig. 12(E)) that is approximately fan-shaped in a plan view, and two side faces (see Fig. 12(E)) that are congruent right-angled triangles with their hypotenuses curved to be recessed.

[0051] In addition, when the ballpoint pen refill 40 in the state shown in Figure 12 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0052] (2-8) Eighth embodiment The ballpoint pen refill 40 with the ballpoint pen tip 10 of the eighth embodiment attached is shown in a front view of FIG. 13(A), an enlarged plan view of FIG. 13(B), an enlarged bottom view of FIG. 13(C), an enlarged front view of the tip portion of FIG. 13(D), and an enlarged front perspective view of the tip portion of FIG. 13(E). The ballpoint pen refill 40 is formed by pressing the insertion part 26 (see FIG. 5(A)-(D)) of the ballpoint pen tip 10 (not shown) into the tip of the cylindrical ink containing tube 41. Therefore, only the tip portion is exposed from the tip of the ink containing tube 41 beyond the cylindrical part 21 of the ballpoint pen tip (see FIG. 13(A), (D), and (E)). On the other hand, the rear end of the ballpoint pen tip 10 attached to the tip can be seen from the opening at the rear end of the ink containing tube 41 (see FIG. 13(C)).

[0053] The cylindrical portion 21 is the portion of the ballpoint pen tip 10 with the largest outer diameter, and the reduced diameter portion 22 constituting the tip side of the cylindrical portion 21 is reduced in diameter in a concave curved shape, and the outer diameter gradually decreases toward the tip. A part of the outer surface of the reduced diameter portion 22 is recessed into four recesses 24. The periphery of the writing ball 30 held at the tip of the reduced diameter portion 22 is a crimped portion 23 that is crimped inward (see Figs. 13(B), (D) and (E)). The recesses 24 are formed as shown in the first manufacturing method. The four recesses 24 are equally spaced in the circumferential direction with respect to the axis (see Fig. 13(B)). Each of the recesses 24 is recessed so that three faces are exposed: a bottom face (see Fig. 13(E)) that is approximately fan-shaped in a plan view, and two side faces (see Fig. 13(E)) that are congruent right-angled triangles with their hypotenuses curved to be recessed.

[0054] In addition, when the ballpoint pen refill 40 in the state shown in Figure 13 (E) is rotated around its axis, the recess 24 of the reduced diameter portion 22 of the ballpoint pen tip 10 rotates, thereby creating a design effect by changing the appearance.

[0055] (2-9)Other In the ballpoint pen refill 40 of each of the above embodiments, the ballpoint pen tip 10 was attached directly to the tip of the ink containing tube 41, but depending on the relationship between the thickness of the ink containing tube 41 and the outer diameter of the ballpoint pen tip 10, a joint may be interposed between the ballpoint pen tip 10 and the ink containing tube 41. [Industrial Applicability]

[0056] The present invention can be used in ballpoint pen tips. [Explanation of symbols]

[0057] 10 Ballpoint Pen Tip 20 holder 21 cylindrical portion 22 reduced diameter portion 23 Crimping portion 24 Recess 25 Colored portion 26 Insertion part 27 Back hole 30 Writing Ball 40 Ballpoint pen refill 41 Ink reservoir tube 50 Broach tool 51 Blade

Claims

1. a holder having a cylindrical portion and a tapered portion that constitutes a tip side of the cylindrical portion and has an outer diameter that gradually decreases toward the tip; A writing ball held at the tip of the reduced diameter portion; a recess formed by recessing a part of an outer surface of the reduced diameter portion; Equipped with The recesses are arranged at equal intervals in the circumferential direction, The recess is colored, A ballpoint pen tip, characterized in that the recess has a bottom surface that is sector-shaped in a plan view and two side surfaces that are congruent right-angled triangles.

2. A method for manufacturing a ballpoint pen tip, comprising: a holder having a cylindrical portion, a tapered portion forming the tip side of the cylindrical portion and having an outer shape that gradually decreases toward the tip; and a writing ball held at the tip of the tapered portion, the method comprising the steps of: cutting a portion of the outer surface of the tapered portion by broaching to form a recess having a bottom that is fan-shaped in a plan view and two side surfaces that are congruent right-angled triangles.

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