Perpetual Pen

Abstract

To provide a fountain pen including a pen body hardly falling from a barrel and hardly scratched on a surface of the pen body in a production step and having a good writing feeling.SOLUTION: In the fountain pen, two rectangular window parts 50 formed symmetrically with a split groove 5d of a pen body 5 as a center axis and having longitudinal parts in a direction along a shaft center are formed at an insertion part 5e inserted into a front opening part 4a of a barrel 4 at a rear side of a fixing part 5a of the pen body 5; an extension part 50a from which the window part 50 extends backward is formed in either one of corner parts at a rear side of the rectangular window part 50; comb grooves 6c formed on an outer face of a pen core 6 inward the window part 50 in a state in which the pen body 5 and the pen core 6 are superposed and inserted are located at the front opening part 4a of the barrel 4; the insertion part 5e excluding the window part 50 in the pen body 5 is held and fixed between the barrel 4 and the pen core 6.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a fountain pen, and more particularly to a fountain pen having a structure in which a pen body and a pen core are inserted in a stacked manner into the front opening of a barrel. [Background technology]

[0002] Conventionally, the pen body of a fountain pen has a fixed part that is stacked to embrace the pen core and inserted into the front opening of the barrel together with the pen core, a tapered elastic part located in front of the fixed part, and a pen point at the tip of the elastic part, and a slit groove is provided along the axis from the pen point to the fixed part. As described in Patent Document 1 (JP Patent Publication 2018-103433), the pen body of this fountain pen has an elastic part and a fixed part that are curved in an arc shape in cross section so as to follow the inner peripheral surface of the barrel and the outer peripheral surface of the pen core, and even if the pen body is made of a soft material such as a so-called gold pen made of 14K or 18K gold, when writing pressure is applied to the pen body, the pen body elastically deforms in a direction away from the pen core in response to the writing pressure, and returns to its original state when the writing pressure is released.

[0003] During the manufacturing process of a fountain pen, the pen body is placed in a rotary barrel polishing machine and rotated to smoothly polish its outer surface. If the pen body is heavy, there is a risk that the surface of the pen body will be damaged by rubbing against other pen bodies.

[0004] In addition, by reducing the mass of the fountain pen's barrel, it is possible to reduce damage caused by barrel polishing. However, simply reducing the thickness of the pen body to reduce its mass may reduce the elasticity of the pen body, resulting in a poor writing feel. Furthermore, simply providing a window in the pen body to reduce its mass may result in greater deformation of the pen body due to the presence of the opening, reducing the pen body's elasticity, or it may not be sufficiently fixed to the front opening of the barrel, making it more likely to fall off. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-103433 A Summary of the Invention [Problem to be solved by the invention]

[0006] To provide a fountain pen in which the pen body is unlikely to fall off the barrel, the surface of the pen body is unlikely to be scratched during the manufacturing process, and which provides a good writing feel. [Means for solving the problem]

[0007] The present invention relates to "1. A fountain pen having a pen body, a fixed part which is stacked so as to embrace a pen core and which is inserted into the front opening of a barrel together with the pen core, a tapered elastic part located in front of the fixed part, a pen point at the tip of the elastic part, and a cut groove formed along the axis from the pen point to the fixed part, and the pen body and the pen core are stacked and inserted into the front opening of the barrel, The pen body is inserted into the front opening of the barrel at the rear of the fixed portion of the pen body, and two rectangular window portions are formed symmetrically with the cut groove of the pen body as a central axis, and have a longitudinal direction along the axis. An extension portion is formed at one of the rear corners of the rectangular window portions, from which the window portion extends rearward. A fountain pen in which, when the pen body and the pen core are inserted into the front opening of the barrel in a stacked manner, a comb groove formed on the outer surface of the pen core is positioned inside the window portion, and the insertion portion of the pen body other than the window portion is clamped and fixed between the barrel and the pen core. 2. A fountain pen as described in paragraph 1 above, in which the peripheral edge of the window portion formed in the pen body has a burr portion protruding toward the back side of the pen body. 3. A fountain pen as described in paragraph 1 or 2 above, in which a locking groove is formed at the rear end edge of the fixed part of the pen body, which locks into a locking protrusion formed on the surface of the pen core to restrict the pen body from retracting, and which aligns the center of the pen body with an ink groove formed along the axis of the pen core. 4. The fountain pen according to any one of items 1 to 3, wherein the vicinity of the outer edge of the window portion in the insertion portion of the pen body is bent toward the pen core, so that when the pen body and the pen core are inserted in an overlapping manner into the front opening of the barrel, the suspension portion formed between the two rectangular windows in the insertion portion of the pen body comes into sliding contact with the inner surface of the barrel when the pen body is inserted.

[0008] According to the present invention, by forming two rectangular window portions in the insertion portion of the pen body, it is possible to reduce the mass even when the pen body is made of a material with a high specific gravity, such as 14K or 18K gold.

[0009] Furthermore, the rectangular window portion can have a large opening, and the suspension portion formed between the two rectangular window portions can be formed in a straight line. Therefore, when the pen body and pen core are stacked and inserted into the front opening of the barrel, the suspension portion at the insertion portion of the pen body can be smoothly inserted by sliding it against the inner surface of the barrel.

[0010] In addition, by forming an extension portion that extends rearward at one of the rear corners of the rectangular window portion, when the pen body and pen core are inserted into the front opening of the barrel by stacking them, the window portion gradually enters the front opening of the barrel, allowing for smooth insertion. Furthermore, by providing a burr portion that protrudes from the periphery of the window portion onto the back surface of the pen body due to processing, the protrusion formed by the extension can prevent the pen body from coming off or rotating.

[0011] In addition, by positioning the comb groove formed on the outer surface of the pen core inside the window with the pen body and pen core overlapping and inserted into the front opening of the barrel, the recess formed by the inner surface of the barrel and the inner periphery of the window becomes a temporary storage area for retaining excess ink that flows out due to thermal expansion that occurs when the air in the ink tank is warmed, and as the ink in the ink groove decreases due to writing, the ink in the recess can be supplied to the ink groove via the comb groove. In addition, when washing the fountain pen with water to change writing colors, etc., the recess formed by the inner surface of the barrel and the inner circumference of the window portion is connected to the comb groove, which has the advantage that water can easily reach the recess, making it easy to clean.

[0012] In addition, by forming an engagement groove at the rear end edge of the fixed part of the pen body that engages with an engagement protrusion formed on the surface of the pen core to restrict retraction of the pen body and aligns the ink groove formed along the axis at the centre of the pen core with the centre of the pen body, it becomes easier to position the pen bodies when stacked to embrace the pen core.

[0013] Furthermore, by bending the vicinity of the outer edge of the window portion in the insertion portion of the pen body towards the pen core, when the pen body and pen core are stacked and inserted into the front opening of the barrel, the suspension portion formed between the two rectangular windows in the insertion portion of the pen body slides against the inner surface of the barrel to insert the pen body, making it easier to insert the pen body. Effect of the Invention

[0014] Because of the above-described structure, the present invention makes it possible to obtain a fountain pen that is comfortable to write with, with the pen body being less likely to fall off the barrel and with the surface of the pen body being less likely to be scratched during the manufacturing process. [Brief description of the drawings]

[0015] [Figure 1] 2 is a plan view of the front part of the fountain pen according to the present embodiment, showing the barrel in cross section. FIG. [Diagram 2]2 is a side view of the front part of the fountain pen according to the embodiment, showing the barrel in cross section. FIG. [Diagram 3] FIG. 2 is a plan view of the pen body of the fountain pen according to the embodiment. [Figure 4] FIG. 2 is a diagram showing the pen body of the fountain pen according to the present embodiment after blanking. [Diagram 5] FIG. 2 is a plan view of a pen core of the fountain pen according to the embodiment. [Figure 6] 1 is a plan view of the pen body and pen core of a fountain pen according to an embodiment of the present invention, stacked on top of each other. [Figure 7] FIG. 13 is a plan view of a pen body of a fountain pen in another embodiment. [Figure 8] FIG. 11 is a diagram showing the state in which the pen body of a fountain pen in another embodiment has been blanked. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The fountain pen of this embodiment will be described in detail below with reference to the drawings.

[0017] Fig. 1 is a plan view of the front part of the fountain pen in this embodiment, showing the barrel in cross section. Fig. 2 is a side view of the front part of the fountain pen in this embodiment, showing the barrel in cross section. Fig. 3 is a plan view of the pen body of the fountain pen in this embodiment. Fig. 4 is a view of the pen body of the fountain pen in this embodiment after blank processing. Fig. 5 is a plan view of the pen core of the fountain pen in this embodiment. Fig. 6 is a plan view of the pen body and pen core of the fountain pen in this embodiment, stacked together. In the description of the drawings, the writing tip side in the drawing is referred to as the front, the opposite side as the rear, the side where the pen body is located relative to the pen core is referred to as the upper side, and the opposite side as the lower side.

[0018] As shown in Figure 1, the fountain pen 1 of this embodiment has a pen body 5 and a pen core 6 inserted in a stacked state into the front opening 4a of a barrel 4, which has a neck tube 3 screwed to the front of the barrel body 2.

[0019] As shown in Figures 1 and 3, the pen body 5 of this embodiment has a fixed portion 5a that is inserted into the front opening 4a of the barrel 4, an elastic portion 5b having a tapered shape located in front of the fixed portion 5a, and a pen point 5c at the tip of the elastic portion 5b, and is provided with a cut groove 5d formed along the axis from the pen point 5c toward the fixed portion 5a. The insertion portion 5e, which is located behind the fixed portion 5a of the pen body 5 and is inserted into the front opening 4a of the barrel 4, has two rectangular window portions 50 that are formed symmetrically around the cut groove 5d of the pen body 5 as the central axis and have their elongated directions along the axis, and an extension portion 50a is formed at the outer corner of the rear of the rectangular window portions 50, from which the window portions 50 extend toward the rear.

[0020] In this embodiment, a V-shaped locking groove 5f that is concave toward the front is formed on the rear end edge of the fixed portion 5a of the pen body 5 shown in Figure 3, which locks into the locking protrusion 6a formed on the surface of the pen core 6 shown in Figure 4. As shown in Figure 5, by placing the pen body 5 on the pen core 6 so that the locking groove 5f locks into the locking protrusion 6a, it is possible to restrict the pen body 5 from retracting relative to the pen core 6 and to easily align the ink groove 6b formed along the axis at the center of the pen core 6 for almost the entire length with the cut groove 5d at the center of the pen body 5.

[0021] Furthermore, when the pen body 5 and pen core 6 are inserted and stacked into the front opening 4a of the barrel 4, the comb groove 6c formed on the outer surface of the pen core 6 is positioned inside the window portion 50, and the recess 51 formed by the inner surface of the barrel 4 and the inner periphery of the window portion 50 serves as a temporary storage area for retaining excess ink (not shown, same below) that flows out due to thermal expansion that occurs when the air in the ink tank 7 is warmed, and as the ink in the ink groove 6b decreases due to writing, the ink in the recess 51 can be supplied to the ink groove 6b via the comb groove 6c. Furthermore, even when washing the fountain pen 1 with water to change writing colors, etc., the recess 51 formed by the inner surface of the barrel 4 and the inner periphery of the window portion 50 is connected to the comb groove 6c, so that the washing water can easily reach the recess 51, making it easier to drain the ink. Furthermore, by making at least the upper part of the two windows 50 of the pen body 5 in the neck tube 3 constituting the barrel tube 4 transparent so that the pen body 5 and the pen core 6 can be seen, when the air inside the ink tank 7 is heated and thermal expansion occurs, the ink overflows and the user can visually see the ink stored in the recess 51 before it overflows. This makes it possible to prevent the fountain pen itself, the paper, etc. from being soiled.

[0022] In this embodiment, the pen body 5 is made of 14K gold with a specific gravity of 13.68, and is made 0.04g lighter by providing two windows 50. This makes the pen body 5 have a mass of 0.475g, and when the pen body 5 is rotated in a rotary barrel polishing machine during the manufacturing process to smoothly polish the outer surface, it is possible to prevent the surface of the pen body 5 from being scratched by multiple pen bodies 5 rubbing against each other.

[0023] Moreover, the rectangular window 50 is formed so as to have a longitudinal direction in the direction along the axis, and can be formed long along the pen body 5, allowing a large opening to be provided, and the mass of the pen body 5 to be significantly reduced. Furthermore, as described above, the suspension portion 5h formed between the two rectangular windows 50 can be formed in a straight line, so that when the pen body 5 and the pen core 6 are inserted in a stacked manner into the front opening 4a of the barrel 4, the suspension portion 5h in the insertion portion 5e of the pen body 5 can be brought into sliding contact with the inner surface of the barrel 4, allowing for smooth insertion.

[0024] Furthermore, in this embodiment, the vicinity of the outer edge of the window portion 50 in the insertion portion 5e of the pen body 5 is provided with a hanging portion 5i that hangs down toward the pen core 6 (downward).Therefore, when the pen body 5 and the pen core 6 are overlappingly inserted into the front opening 4a of the barrel 4, the pen body 5 is inserted in sliding contact with the inner surface of the front opening 4a of the barrel 4 using the suspension portion 5h formed between the two rectangular window portions 50 in the insertion portion 5e of the pen body 5 as a reference, without touching the hanging portion 5i, making it easy to insert the pen body 5. In addition, the step 5j formed on the upright portion 5i of the pen body 5 engages with a step 6d formed opposite the protrusion 5j on the side of the pen core 6, thereby making it difficult for the pen body 5 to fall out from the front of the barrel 4 when the pen body 5 and the pen core 6 are inserted and stacked in the front opening 4a of the barrel 4.

[0025] In addition, the fixed portion 5a and the elastic portion 5b of the pen body 5 are curved in an arc shape in cross section so as to fit the inner surface of the barrel 4 and the outer surface of the pen core 6. Although the pen body 5 is made of 14K gold, a soft material, as mentioned above, when writing pressure is applied to the pen body 5, the pen body 5 elastically deforms in the direction away from the pen core 6 (upward) in response to the writing pressure, and returns to its original state when the writing pressure is released. 3, the pen body 5 of this embodiment is formed with a total length L of 25.25 mm, a length L1 of the fixed portion 5a of 7.75 mm, and a length L2 of the elastic portion 5b of 17.5 mm. The pen body 5 is formed so that the radius of the inner surface of the fixed portion 5a is uniformly 3.0 mm, and the radius of the arc shape of the inner surface of the elastic portion 5b is 3.0 mm on the fixed portion 5a side and gradually increases from there toward the tip, with the radius of the maximum width being 6.0 mm, and the radius from the maximum width to the tapered portion being 7.0 mm near the pen point 5c. The thickness of the pen body 5 is gradually increased toward the front, from 0.2 mm at the rear end to 0.5 mm at the front end. In addition, the width of the narrowest fixed portion 5a of the pen body 5 is 5.35 mm, and the overall length of the window portion 50 is 4.85 mm, which is narrower than the width of the fixed portion 5a. Therefore, even when multiple pen bodies 5 are placed in a rotary barrel polishing machine for polishing, the multiple pen bodies 5 are less likely to become tangled with each other.

[0026] In this embodiment, when the pen body 5 and the pen core 6 are inserted and stacked into the front opening 4a of the barrel 4, the fixed portion 5a of the pen body 5 extends 6.6 mm into the front opening 4a of the barrel 4, and the front edge of the window portion 50 is spaced 0.65 mm from the front opening 4a of the barrel 4. Therefore, the two windows 50 opened in the pen body 5 are recessed within the barrel 4, and therefore there is no reduction in the elasticity of the pen body 5, which would affect the writing feel. In particular, in this embodiment, the pen body 5 has strength obtained even if the openings made by the two windows 50 are large, and as a result, there is no reduction in the elasticity of the pen body 5.

[0027] 1 and 2, when the pen body 5 and the pen core 6 are inserted in the front opening 4a of the barrel 4, the comb groove 6c formed on the outer surface of the pen core 6 is located inside the window 50, and the insertion part 5e of the pen body 5 other than the window 50 is sandwiched and fixed between the barrel 4 and the pen core 6. In this embodiment, the peripheral part of the window 50 has a burr part (not shown, the same applies below) that protrudes from the processing on the lower side (back side) of the pen body 5, and further, the back side (lower) of the protrusion 5g formed at the outer edge of the extension 50a also has a burr part that protrudes from the processing, so that the burr part is caught on the surface of the pen core 6, preventing the pen body 5 from coming off or rotating. The protrusion 5g has a vertical part in the direction along the axis and a horizontal part in the direction perpendicular to the vertical part, which makes it possible to prevent the pen body 5 from falling off the pen core 6 and also prevents the pen body 5 from rotating relative to the pen core 6, allowing for stable writing.

[0028] Fig. 7 is a plan view of the pen body of a fountain pen in another embodiment. Fig. 8 is a view of the pen body of a fountain pen in another embodiment after blank processing. The pen body 5' shown in Fig. 7 has, in the same manner as the pen body 5 shown in Fig. 3, two rectangular window sections 50' formed symmetrically with respect to the cut groove 5d of the pen body 5' as the central axis and having their longitudinal direction along the axis in the insertion section 5e of the pen body 5. The main difference from the pen body 5 shown in Fig. 3 is that an extension section 50a' from which the window section 50' extends rearward is formed at the inner rear corner of the rectangular window section 50', and a protrusion 5g' formed at the outer edge of the extension section 50a has a vertical section in the direction along the axis and an inclined section inclined at 45 degrees, but otherwise is the same. [Explanation of symbols]

[0029] 1...fountain pen, 2...barrel body, 3...neck barrel, 4...Shaft cylinder, 4a...Front opening, 5...pen body, 5a...fixed part, 5b...elastic part, 5c...pen point, 5d...cut groove, 5e...insertion part, 5f...locking groove, 5g...protrusion, 5h... Suspended part, 5i... Suspended part, 5j... Stepped part, 50: window portion, 50a: extension portion, 51: recess portion, 6...pen core, 6a...engagement protrusion, 6b...ink groove, 6c...comb groove, 6d…Step, 7…Ink tank, 5': pen body, 50': window portion, 50a': extension portion, 5g': protrusion portion.

Claims

1. A fountain pen having a pen body which is stacked to hold a pen core and is inserted into a front opening of a barrel together with the pen core, a tapered elastic portion located in front of the fixing portion, a pen point at the tip of the elastic portion, and a cut groove formed along the axis from the pen point toward the fixing portion, and the pen body and the pen core are stacked and inserted into the front opening of the barrel, The pen body is inserted into the front opening of the barrel at the rear of the fixed portion of the pen body, and two rectangular window portions are formed symmetrically with the cut groove of the pen body as a central axis, and have a longitudinal direction along the axis. An extension portion is formed at one of the rear corners of the rectangular window portions, from which the window portion extends rearward. A fountain pen in which, when the pen body and the pen core are inserted into the front opening of the barrel in a stacked manner, a comb groove formed on the outer surface of the pen core is positioned inside the window portion, and the insertion portion of the pen body other than the window portion is clamped and fixed between the barrel and the pen core.

2. 2. The fountain pen according to claim 1, wherein the periphery of the window formed in the pen body has a burr portion protruding toward the back surface of the pen body.

3. A fountain pen as described in claim 1 or 2, wherein a locking groove is formed at the rear end edge of the fixed part of the pen body, which locks with a locking protrusion formed on the surface of the pen core to restrict the pen body from retracting, and which aligns the center of the pen body with an ink groove formed along the axis of the pen core.

4. A fountain pen as described in any one of claims 1 to 3, wherein the vicinity of the outer edge of the window portion in the insertion portion of the pen body is bent toward the pen core, so that when the pen body and the pen core are inserted in a stacked manner into the front opening of the barrel, the pen body is inserted with a suspension portion formed between the two rectangular window portions in the insertion portion of the pen body sliding against the inner surface of the barrel.

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