Pen nibs for dip pens and methods for manufacturing pen nibs
The dip pen nib with angled grooves and a detachable design addresses ink type changes, writing comfort, and durability issues, enabling long-lasting writing and consistent line width.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- ITOYA CO LTD
- Filing Date
- 2024-12-27
- Publication Date
- 2026-07-09
AI Technical Summary
Existing pens face challenges in easily changing ink types without compromising writing feel, durability, and maintaining consistent line width, as they either require cumbersome tank cleaning, handmade variations, or struggle with groove angles affecting ink retention and writing comfort.
A dip pen nib with a frustoconical body featuring multiple longitudinal grooves of varying angles and a detachable design, manufactured using a three-stage cutting process, ensures easy ink type changes, maintains consistent line width, and enhances durability by using metal materials.
The design allows for long-lasting writing with a single dip, easy ink type switching, and ensures a good writing feel while preventing variations in line width and durability through surface tension and metal strength.
Smart Images
Figure 2026115819000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a pen tip of a felt pen and a method for manufacturing the pen tip, which perform writing and drawing while applying ink to the pen tip.
Background Art
[0002] In recent years, the types (colors and characteristics) of inks that can be used in felt pens, glass pens, and fountain pens have increased rapidly, and there is a demand for pens that can easily change the type of ink.
[0003] As a fountain pen, there is one that includes a pen shaft having an ink tank holding ink, a pen tip provided at the tip of the pen shaft, and a relay core that guides the ink in the ink tank to the pen tip (for example, see Patent Document 1). Changing the type of ink is performed by changing the ink held in the ink tank.
[0004] As a glass pen, there is one in which a glass pen tip having a straight groove is detachably provided on a pen shaft (for example, see Patent Document 2). By washing the pen tip with water, the type of ink can be changed.
[0005] As a felt pen, there is one in which a plurality of grooves having different depths are formed on a conical pen tip made of metal (for example, see Patent Document 3). Similar to a glass pen, by washing the pen tip with water, the type of ink can be changed.
Prior Art Documents
Patent Documents
[0006]
Patent Document 1
Patent Document 2
Patent Document 3
Summary of the Invention
[0007] However, with the fountain pen described in Patent Document 1 above, changing the type of ink required first discarding the ink currently in the ink tank and then cleaning the ink tank, nib, and lead, making the process of changing ink types cumbersome.
[0008] Furthermore, while the glass pen described in Patent Document 2 above allows for easy change of ink type, the nib is handmade by a glass craftsman, resulting in variations in nib thickness and groove width. Consequently, the amount of ink held in the nib and the width of the written lines differed from one pen to another. Additionally, because the nib is made of glass, it could chip or break due to impact.
[0009] Furthermore, while the dip pen described in Patent Document 3 allows for easy changes in ink type and ensures strength due to its metal tip, the constant angle of the grooves formed on the tip makes it difficult to maintain a good writing feel while retaining a large amount of ink in the vertical grooves and writing for extended periods with a single dip.
[0010] Therefore, the present invention aims to provide a dip pen nib and a method for manufacturing the nib that allows for easy changes in ink type, maintains a good writing feel without causing individual differences in line width, allows for long-term writing with a single dip in ink, and ensures durability. [Means for solving the problem]
[0011] To achieve the above objective, the pen tip of the dip pen of the present invention comprises a frustoconical body portion and a connecting portion, and is detachably attached to a pen shaft via the connecting portion, wherein the pen tip is made of metal, and the body portion has a plurality of longitudinal grooves extending from the tip to the base, the longitudinal grooves being an ink application portion formed parallel to the inclination of the frustoconical body portion from the tip to the base, an ink holding portion that is continuously formed from the ink application portion toward the base of the body portion and gradually deepens toward the base, and the deepest groove portion where the ink holding portion is deepest The ink coating portion is characterized by comprising a shallow inclined portion that gradually becomes shallower toward the groove, the ink coating portion being composed of a first angle portion formed at a predetermined angle on the bottom side of the groove, and a second angle portion formed from the first angle portion toward the opening of the groove with a smaller groove angle than the first angle portion, and the ink holding portion being composed of the first angle portion formed on the bottom side of the groove, the second angle portion formed from the first angle portion toward the opening of the groove, and a third angle portion formed from the second angle portion toward the opening of the groove with a smaller groove angle than the second angle portion.
[0012] Furthermore, it is preferable that the groove angle of the first angled portion is 120°, the groove angle of the second angled portion is 90°, and the groove angle of the third angled portion is 60°.
[0013] Furthermore, the present invention provides a method for manufacturing the nib of a dip pen, comprising a frustoconical body portion and a connecting portion, the nib of a dip pen being detachably attached to a pen shaft via the connecting portion, comprising: a body portion processing step of cutting the frustoconical shape of the body portion; a vertical groove processing step of cutting a plurality of vertical grooves on the outer circumferential surface of the body portion with a three-stage cutting edge having a first cutting edge surface, a second cutting edge surface, and a third cutting edge surface where the angle between the cutting edge surfaces decreases sequentially from the top of the cutting edge; a finishing processing step of finishing the body portion; and an electrolytic polishing step of electrolytically polishing the body portion, wherein the vertical groove processing step includes an ink application portion processing step of cutting grooves parallel to the inclination of the frustocone of the body portion from the tip side of the body portion using the first cutting edge surface and the second cutting edge surface; and an ink holding portion processing step of cutting grooves gradually deeper toward the base side of the body portion using the first cutting edge surface, the second cutting edge surface, and the third cutting edge surface.
[0014] Furthermore, it is preferable that the vertical groove machining process includes a shallow inclined section machining process in which the ink-holding portion formed in the ink-holding portion machining process is gradually formed from the deep groove portion, where the ink-holding portion formed in the ink-holding portion machining process is deepest, toward the base of the main body portion, using the first cutting edge surface, the second cutting edge surface, and the third cutting edge surface.
[0015] Furthermore, it is preferable that the three-stage blade is formed with the first cutting edge surface having an angle of 120°, the second cutting edge surface having an angle of 90°, and the third cutting edge surface having an angle of 60°. [Effects of the Invention]
[0016] According to the pen tip of the present invention, by forming vertical grooves as described above, the ink application section, composed of the first and second angled sections, maintains a good writing feel, while the ink retention section, composed of the first, second, and third angled sections, can hold a certain amount of ink due to surface tension. This allows for long-lasting writing with a single dip. Furthermore, the first angled section, where the groove angle is formed to be the largest, allows for thorough cleaning of the ink by washing the pen tip with water, making it easy to change ink types. In addition, there is no risk of individual differences in line width, and the strength of the pen tip is ensured. [Brief explanation of the drawing]
[0017] [Figure 1] This is an enlarged front view of a pen tip showing one embodiment of the present invention. [Figure 2] This is also a magnified plan view of the pen tip. [Figure 3] This is an enlarged cross-sectional view of line III-III in Figure 1. [Figure 4] This is an enlarged view of section A1 in Figure 3. [Figure 5] This is an enlarged cross-sectional view of VV in Figure 1. [Figure 6] This is an enlarged view of section A2 in Figure 5. [Figure 7] This is an explanatory diagram of the vertical groove. [Figure 8]It is a front view of a felt pen showing an exemplary form of the present invention. [Figure 9] It is also a cross-sectional view of the felt pen. [Figure 10] It is an explanatory view of a three-edge blade for cutting a longitudinal groove.
Mode for Carrying Out the Invention
[0018] Figs. 1 to 9 are views showing an exemplary form of the felt pen of the present invention. The felt pen 1 of this exemplary form is composed of a pen tip 10 and a pen shaft 20 as shown in Figs. 8 and 9, and the pen tip 10 is detachably connected to the pen shaft 20.
[0019] The pen tip 10 has a main body portion 10a formed in a frustum of a cone shape and a male screw portion 10b (connecting portion) for connecting to the pen shaft 20, and is formed of a metal such as titanium or stainless steel, for example. In the main body portion 10a, eight longitudinal grooves 11 having a substantially V-shaped cross section are provided at equal intervals in the circumferential direction from the tip portion 10c toward the base portion 10d.
[0020] Each longitudinal groove 11 includes an ink application portion 11a cut parallel to the inclination of the frustum of the cone of the main body portion 10a from the tip portion 10c toward the base portion 10d side, an ink holding portion 11b formed continuously from the ink application portion 11a and gradually deeper toward the base portion 10d side, and a shallow inclination portion 11d formed gradually shallower from the deep groove portion 11c where the ink holding portion 11b is deepest toward the base portion 10d.
[0021] The tip of the ink application portion 11a is formed in a hemispherical shape. As shown in Figs. 3 and 4, the ink application portion 11a is composed of a first angle portion 11e having an angle of 120° at the bottom side of the groove formed and a second angle portion 11f provided from the first angle portion 11e toward the opening side of the groove and having a smaller groove angle than the first angle portion 11e, for example, 90°.
[0022] As shown in Figures 5 and 6, the ink-holding portion 11b is composed of a first angled portion 11e formed on the bottom side of the groove, a second angled portion 11f formed on the groove opening side of the first angled portion 11e, and a third angled portion 11g provided from the second angled portion 11f toward the groove opening, with a smaller groove angle than the second angled portion 11f, for example, 60°.
[0023] In this embodiment, the ink-coated portion 11a is formed to a depth of 0.06 mm and to a length of 3 mm from the tip. The shallow inclined portion 11d is formed in the shape of a circular arc with a radius of 10 mm.
[0024] The pen tip 10 formed in this way can hold the most ink due to surface tension at the third angled portion 11g of the ink-holding portion 11b, where the groove angle is formed at 60°, when the pen tip 10 is immersed in ink. Furthermore, when applying ink (writing or drawing), the second angled portion 11f of the ink-applying portion 11a, where the groove angle is formed at 90°, comes into contact with the application surface, such as paper. However, the second angled portion 11f, which is formed at a larger angle than the third angled portion 11g, can reduce friction with the paper surface, resulting in a better writing experience.
[0025] Furthermore, since the first angled portion 11e formed on the bottom side of the ink coating portion 11a and the ink holding portion 11b is formed at an obtuse angle of 120°, the original type of ink can be effectively cleaned from the bottom side of the groove when changing the type of ink.
[0026] Thus, the pen tip 10 maintains a good writing feel in the ink application section 11a, while the ink holding section 11b holds a consistent amount of ink well, allowing for writing or drawing for extended periods. Furthermore, when changing ink types, the original ink can be easily cleaned, making it easy to switch between ink types.
[0027] The pen shaft 20 is made of metal, resin, wood, or the like, and has a hollow shaft portion 20a and a tip member 20b provided at the tip of the shaft portion 20a. The tip member 20b is provided with a female thread portion 20c, and the pen tip 10 is detachably connected to the pen shaft 20 by fitting the male thread portion 10b of the pen tip 10 into the female thread portion 20c.
[0028] Next, we will explain the manufacturing method of the pen tip 10.
[0029] The main body portion 10a is formed, for example, by machining it with an NC lathe, in which a main body machining process (rough machining process) is performed in which a frustoconical shape is cut and the tip of the frustoconical shape is cut into a hemispherical shape, a longitudinal groove machining process is performed in which eight longitudinal grooves 11 are machined on the outer surface of the main body portion 10a, a finishing machining process is performed to finish the frustoconical shape and the hemispherical tip, and an electrolytic polishing process is performed to remove burrs from the surface by electrolytic polishing.
[0030] The vertical groove machining process includes an ink coating section machining process in which the ink coating section 11a is machined with a three-stage blade 12 as shown in Figure 10, an ink holding section machining process in which the ink holding section 11b is machined, and a shallow inclined section machining process in which the shallow inclined section 11d is machined.
[0031] As shown in Figure 10, the three-stage blade 12 has a first cutting edge surface 12a at the top P1 side with an angle θ1 of 120°, a second cutting edge surface 12b below the first cutting edge surface 12a with an angle θ2 of 90°, and a third cutting edge surface 12c below the second cutting edge surface 12b with an angle θ3 of 60°, all of which are sequentially and integrally provided. The depth L1 of the first cutting edge surface 12a and the depth L2 of the second cutting edge surface 12b are both 0.03 mm.
[0032] As shown in Figure 7, in the ink coating section processing step, a groove with a depth of 0.06 mm is cut parallel to the inclination of the frustocone of the main body 10a (11.8°) using a three-stage cutting blade 12, starting 3 mm below the tip of the frustocone that forms the main body 10a (the tip before the tip is cut into a hemispherical shape). Furthermore, the tip 10c is cut into a hemispherical shape. This forms the ink coating section 11a, which is composed of a first angled section 11e and a second angled section 11f.
[0033] Next, in the ink-holding portion processing step, the same three-stage cutting blade 12 is used to cut a groove that gradually deepens from the ink-coating portion 11a toward the base portion 10d of the main body portion 10a, for example, in this embodiment the groove depth is formed to 0.06 mm to 1.02 mm. This forms the ink-holding portion 11b, which is composed of a first angle portion 11e, a second angle portion 11f, and a third angle portion 11g.
[0034] Next, in the shallow inclined section machining process, the groove is cut from the deep groove 11c of the ink-holding section 11b toward the base 10d using the same three-stage cutting tool 12 so that it forms an arc shape with a radius of 10 mm when viewed from the side, and the shallow inclined section 11d is formed to become progressively shallower toward the base 10d.
[0035] As described above, the nib of this example is formed in such a way that a single dip in ink allows for long-lasting, smooth writing. Furthermore, the type of ink can be easily changed by washing the nib with water. In addition, forming the nib from metal ensures its strength. In particular, when the nib is made of titanium, both strength and lightness are ensured, making it less likely to cause writing fatigue even during prolonged use. Moreover, since the vertical grooves are machined using an NC lathe, there is no risk of individual variations in the width or depth of the grooves.
[0036] Furthermore, the present invention is not limited to the embodiments described above. The length and depth of the vertical grooves can be appropriately determined according to the length and diameter of the pen tip, and is not limited to forming grooves with a depth of 0.06 mm to 1.02 mm as in the embodiments described above. The number of vertical grooves is also arbitrary. Moreover, the angle of the grooves is not limited to 120°, 90°, or 60°, but can be set while adjusting as appropriate. [Explanation of Symbols]
[0037] 1…Dip pen, 10…Pen tip, 10a…Body, 10b…Male thread, 10c…Tip, 10d…Base, 11…Longitudinal groove, 11a…Ink application area, 11b…Ink retention area, 11c…Deep groove, 11d…Shallow bevel, 11e…First angle, 11f…Second angle, 11g…Third angle, 12…Three-stage blade, 12a…First cutting edge surface, 12b…Second cutting edge surface, 12c…Third cutting edge surface, 20…Pen shaft, 20a…Shaft, 20b…Tip component, 20c…Female thread
Claims
1. A pen tip for a dip pen, comprising a frustoconical body and a connecting part, which is detachably attached to a pen shaft via the connecting part, The pen tip is made of metal, and the body has a plurality of vertical grooves extending from the tip to the base. The longitudinal groove extends from the tip towards the base. The ink application section is formed parallel to the inclination of the frustocone of the main body, An ink-holding portion is formed that gradually deepens from the ink-coating portion toward the base of the main body, The ink-holding portion comprises a deep groove portion that is the deepest part of the ink-holding portion, and a shallow inclined portion that gradually becomes shallower towards the base. The ink coating portion is composed of a first angled portion formed at a predetermined angle on the bottom side of the groove, and a second angled portion formed from the first angled portion toward the opening of the groove, with a smaller groove angle than the first angled portion. The pen tip of a dip pen is characterized in that the ink-holding portion is composed of a first angled portion formed on the bottom side of the groove, a second angled portion formed extending from the first angled portion toward the opening side of the groove, and a third angled portion formed extending from the second angled portion toward the opening of the groove, with a smaller groove angle than the second angled portion.
2. The nib of a dip pen according to claim 1, characterized in that the first angled portion has a groove angle of 120°, the second angled portion has a groove angle of 90°, and the third angled portion has a groove angle of 60°.
3. A method for manufacturing a pen tip for a dip pen, comprising a frustoconical body and a connecting part, which is detachably attached to a pen shaft via the connecting part, A main body machining process in which the frustoconical shape of the main body is cut, A vertical groove machining process is performed on the outer circumferential surface of the main body by cutting with a three-stage cutting edge having a first cutting edge surface, a second cutting edge surface, and a third cutting edge surface, the angle formed by the cutting edge surfaces decreasing sequentially from the top of the cutting edge. A finishing process for finishing the main body, The system includes an electrolytic polishing step for electrolytically polishing the main body, The aforementioned longitudinal groove machining process is, An ink coating process is performed by cutting a groove parallel to the inclination of the frustocone of the main body from the tip side of the main body using the first cutting edge surface and the second cutting edge surface, An ink-holding portion machining process in which grooves are gradually cut deeper toward the base side of the main body portion using the first cutting edge surface, the second cutting edge surface, and the third cutting edge surface, A method for manufacturing the tip of a dip pen, characterized by containing the following:
4. The method for manufacturing a pen tip for a dip pen according to claim 3, characterized in that the vertical groove machining step includes a shallow inclined section machining step in which the ink-holding portion formed in the ink-holding portion machining step is gradually formed to become shallower from the deep groove portion, where the ink-holding portion formed in the ink-holding portion machining step is deepest, toward the base of the main body portion, by the first cutting edge surface, the second cutting edge surface, and the third cutting edge surface.
5. The method for manufacturing a pen tip for a dip pen according to claim 3 or 4, characterized in that the three-stage blade is formed with an angle of 120° for the first cutting edge surface, an angle of 90° for the second cutting edge surface, and an angle of 60° for the third cutting edge surface.