JPS6224545Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a core for guiding ink in a capillary type writing instrument.

Conventionally, various types of ink guide cores have been proposed for thin tube type writing instruments having such ultra-fine ink guide holes, such as drafting pens, recorder pens, and water-based ballpoint pens for ultra-fine characters. At present, many improvements are still required in order to satisfy both retention characteristics and outflow characteristics and to obtain good writing feel and line drawing characteristics. In conventional ink guide cores made of ultrafine metal wires, the ink guide holes of the thin tubes are simply formed into ring-shaped pores, resulting in weak capillary action.

On the other hand, cores made of ultra-fine synthetic resin wires can be easily molded into irregular cross-sectional shapes, and some are known to have improved configurations, but even with these, there are grooves on the outer peripheral surface of the core or have complicated grooves formed only inside the core, the limited cross-sectional area of the ultra-fine ink guide hole is reduced, and the capillary tubes are biased towards either the center or the outer periphery. will be formed. Therefore, not only is there a shortage of capillary tubes, but also the core structure itself is defective, resulting in fading and discontinuation of the writing line during writing, and fading at the beginning of writing due to the ink return phenomenon called drain back. It was a victory because of this.

The purpose of the present invention is to solve these deficiencies in the ink guide core, to effectively utilize the limited cross section of the ultra-thin ink guide hole, and to appropriately prevent the drain back phenomenon. The purpose is to propose a core that can do this.

In the present invention, on each side wall surface of an appropriate number of protruding pieces formed radially from the center, long branch-like pieces protruding laterally are arranged facing only in one direction of rotation about the center. and at least one short branch-like piece is arranged radially inward of the long branch-like piece facing in the same direction as the rotational direction, and is surrounded by the long branch-like piece and the protruding piece adjacent to each other. The core consists of a deformed monofilament-shaped core made of synthetic resin, which is formed by dividing the voids into smaller sections by the short branch pieces to form ink conduction paths in the shape of a number of connected circular arcs, and the core has a longitudinal axis. The long branch-like piece is twisted in one direction around the protruding piece, and the long branch-like piece is arranged so that a space serving as an ink passage groove is left with respect to a concentric circle touching the end wall of the protruding piece. The gist of this invention is a core for guiding ink in a capillary type writing instrument.

That is, according to the present invention, (i) the core for guiding ink in a capillary type writing instrument is
An appropriate number of protruding pieces formed radially from the center;
Since it is composed of two types of branch pieces, long and short, that protrude from the side wall surface of each protruding piece, even when installed in a thin tube with a relatively small inner diameter, the internal space of the thin tube can be effectively saved. It is possible to form a large number of ink passageways in the form of connected circular arcs by subdividing the tube, making it possible to effectively utilize the limited cross-sectional area within the tube. By arranging the shaped piece on the side wall surface of the radially protruding piece so that it faces only in one rotation direction, it is possible to easily impart twist in the one rotation direction to the core, and by anticipating this twist in advance, die design can be improved. Furthermore, (iii) the long branch-like pieces protruding from the side wall surfaces of the radial protruding pieces can be placed with a space left as an ink passage groove relative to the concentric circle touching the end wall of the protruding pieces. By doing so, remarkable effects such as being able to always secure an effective ink conduction path in the outer peripheral area even when the core is installed in a thin tube with a relatively small inner diameter are achieved. It is something.

Hereinafter, the present invention will be explained with reference to the illustrated embodiments.

FIG. 1 is a side view of the ink guiding core of the capillary type writing instrument according to the present invention, and FIG. 2 is a cross-sectional view of the core. This core 10 is formed from a core body 1 in the shape of an irregular monofilament, which is made by converging and bonding filaments made of thermoplastic synthetic resin such as polyacetal, nylon, or polyolefin. It is molded using an extrusion molding machine. The core body 1 has a center part 2, and six protruding pieces 3 are formed radially from the center part 2, and radial gaps 5 are formed between the adjacent protruding pieces 3, and each protruding piece The side wall of the piece 3 has branch-like pieces 4a and 4b of different lengths projecting laterally from the wall surface. As shown in FIG. 3, the long branch-like piece 4a among the above-mentioned branch-like pieces has a side wall surface centered on the center of the core body 1,
The short branch-like pieces 4b are arranged so as to be in contact with the circle passing through the center of the circular end portion 3a of the protrusion piece 3, and extend from one side wall of the protrusion piece 3 in the same rotational direction. 4a and the center of the core body 1, and further subdivides the radial slit 5 to form extremely thin capillary tubes 6, 7.

FIG. 4 shows an example of a writing instrument using an ink guiding core 10 according to the present invention, which is obtained by cutting and processing the irregularly shaped monofilament core 1 constructed as described above into an appropriate length and shape. be. The writing part metal thin tube 21 is fitted to the neck 20a of the writing instrument 20 via the adapter 22, the core 10 is loosely inserted into the inner hole of the thin tube 21, and the locking part 11 formed as appropriate at one end of the core is inserted into the adapter 22. The core is attached so that it abuts against the inner shoulder, and the other end 12 of the core protrudes slightly from the tip of the thin tube 21. The porous fiber bundle binding body 23 is inserted into the opening of the adapter 22, and the binding body 2
The locking portion 1 is attached to the elastic resin treated surface 24 of No. 3.
1 is pressed to connect, and the other end 25 of the binding body 23 is inserted into the ink storage body 26. Note that the thin tube 21
may be made of ceramic or a composite material of metal and ceramic.

As shown in FIG. 5, the capillary writing instrument 20 configured as described above has a capillary tube 21 located outside the long branch-like piece 4a of the core 10 of the present invention inside the capillary tube 21 constituting the writing section. It has a large number of extremely fine ink passage grooves 8 along the inner circumference 21a,
The ink has a large number of ultra-fine capillaries 6 and 7 that are inwardly limited by the branch pieces 4a, 4b and the protruding piece 3 and are continuous to the radial slit 5, and has a strong capillary action that takes on the shape of a connected circular arc as a whole. A conductive path 9 is provided.

As a result, an even capillary distribution is obtained in the writing section thin tube of the writing instrument from the center to the inner wall surface of the thin tube, and there is no partial bias in the capillary distribution unlike in conventional products. In particular, the core 10 according to the present invention
(Core body 1) is a protruding piece 3 that extends from the side wall surface of the long branch-like piece 4a.
Since the arrangement is such that the end wall 3 of the protruding piece 3 is in contact with a circle passing through the center of the circular end 3a of the projecting piece 3,
A space that becomes the ink passage groove 8 remains between the concentric circle substantially touching a, that is, the inner wall surface of the thin tube 21 and the long branch piece 4a, and therefore a continuous ink passage 9.
It forms and exerts remarkable effects, and
By simply considering the relative relationship between the diameter of the circular end portion of the protruding piece 3 and the width of the branch piece 4a, the space size can be specified and the ink passage groove 8 can be easily designed. Furthermore, since the number of ink passage grooves 8 is large, the core 10 can be held in a floating state by the surface tension of the ink within the thin tube 21, and the optimal floating state is determined by the outer diameter of the center 10 or This can be obtained by appropriately determining the inner diameter of.

In addition, by appropriately arranging the long branch-like pieces, the ink passage groove 8 is formed with a larger volume and gap width than the ultra-fine capillary tubes 6 and 7, and the capillary force increases from the outer periphery of the core body 1 toward the center. It becomes possible to obtain an attractive force gradient that In this case, not only can the amount of ink held in the capillary tube be increased, but also the ink is easily guided from the channel 8 to the capillary tubes 6 and 7, and there is no shortage of ink in the center when writing. It also has the advantage of preventing blurring and interruptions in handwriting even during high-speed writing that consumes ink. In addition, with the configuration in which the branch pieces 4 are arranged and connected in the same rotation direction from one side wall of the protruding piece 3, that is, in one rotation direction with the center of the core 10 (core body 1) as the rotation axis, the core body 1 can be rotated. During molding, molding shrinkage occurs only in one rotational direction, and the molten resin bundle discharged from the die can be cooled and solidified as if it were swirling, making it easy to form a highly flexible spiral core 1. The radial gap 5 can also be narrowed.

The above molding shrinkage rate depends on the temperature of the molten resin and other molding conditions, and can be changed as appropriate for the purpose of controlling the width and amount of the radial gaps 5.
Therefore, the optimal slit width and amount can be easily obtained according to the required writing characteristics, and when designing the die, the width of the slit of the die can be set wide by taking into account molding shrinkage in one rotation direction. This makes die design easier.

As described above, the ink guiding core according to the present invention has a continuous shape in which the entire conductive path is narrow and connected with complicated circular arcs within the capillary, and moreover, it is possible to form a large number of capillary tubes of the optimum size. Strong capillary action can be imparted to the writing parts of capillary writing instruments having various diameters and lengths.

Therefore, it is possible to improve the ink retention and outflow characteristics of the writing instrument, and in turn, it is possible to obtain good ink followability and clear handwriting without interruptions in ink outflow. Furthermore, when the ink is left unused, the so-called drain back phenomenon in which ink returns to the inside from the writing section does not occur, and fading at the beginning of writing can be prevented.

FIGS. 6 and 7 show other embodiments using the core for guiding ink according to the present invention.

The ink guide core according to the present invention is a water-based ballpoint pen or a water-based ballpoint pen constructed by forming a ball seat 31 and an ink guide hole 32 in a thin tube 30 and inserting the core into the thin tube, as shown in FIG. As shown in Figure 7, a writing part thin tube 40 and a long ink guiding thin tube 41
Even in a recorder pen or the like constructed by inserting a core into the thin tube of the writing section, the above-mentioned remarkable effects can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a side view of the core for guiding ink according to the present invention, FIG. 2 is a cross-sectional view taken along the line - in FIG.
Fig. 3 is an enlarged sectional view of the main part of Fig. 2, Fig. 4 is a longitudinal sectional view showing the main part of an example of a writing instrument equipped with a core according to the present invention, and Fig. 5 is taken along the - line in Fig. 4. 6 and 7 are a longitudinal sectional view and a perspective view of a main part, respectively, showing other examples of a writing instrument equipped with a core according to the present invention. 1...Core body, 2...Center part, 3...Protruding piece, 4
a, 4b... branch piece, 5... radial slit, 6,7
... Capillary tube, 8 ... Ink passage groove, 9 ... Ink passage, 10 ... Core, 21, 30, 40 ... Thin tube.

Claims (1)

[Scope of utility model registration request] On each side wall surface of an appropriate number of protruding pieces formed radially from the center, long branch-like pieces protruding laterally are arranged facing only in one direction of rotation about the center, and at least one two short branch-like pieces are arranged radially inwardly of the long branch-like piece facing in the same direction as the rotational direction, and a gap surrounded by the long branch-like piece and the protruding piece adjacent to each other is It consists of a deformed monofilament core made of synthetic resin, which is further subdivided by short branch pieces to form ink conduction paths in the shape of a large number of connected circular arcs, and the core has a uniform shape around its longitudinal axis. A thin tube type writing instrument, characterized in that the long branch-like piece is twisted in a direction, and the long branch-like piece is arranged so that a space serving as an ink passage groove is left with respect to a concentric circle in contact with the end wall of the protruding piece. Core for guiding ink.