JPS608239B2 - low viscosity ink writing instrument - Google Patents

Description

Detailed Description of the Invention The most important thing to keep in mind when writing with low viscosity ink such as water-based ink or alcohol-containing ink stored in the reservoir is a ballpoint pen, felt pen, etc. First, when writing, ink always comes out in just the right amount.

That is, in this type of writing instrument, the base of the lead protrudes or is exposed into the ink reservoir, and in the case of a ballpoint pen, the ink travels around the guide lead, which is a solid body, and In the case of Feltben, it passes through the inside of a fibrous core and is supplied to its tip. However, if the ink and air inside the reservoir expand due to the temperature of the scribe's hand or the outside temperature, the ink will flow out excessively.
Eventually, it begins to drip from the tip of the core.

Furthermore, as the user writes, the amount of ink in the reservoir decreases, but unless the accompanying decrease in air pressure within the reservoir is properly compensated for, the ink will flow out unsmoothly, eventually making it impossible to write. In order to eliminate this inconvenience, when the ink or air in the reservoir expands, the ink that is about to flow out is bypassed to a location other than the vent core and temporarily stored. When the pressure inside the storage cylinder decreases, outside air may be automatically introduced into the storage cylinder.

Conventionally, various proposals have been made to achieve this purpose, but all of them have complex structures and
Functionally, it could not be said that it was necessarily satisfactory.

The purpose of the present invention is to be able to supply ink properly and smoothly regardless of changes in temperature or atmospheric pressure, and to ensure that the ink stops working during periods of static calendar, that is, times of inconvenience. Yes, and there is a mechanism for that.
To provide a water-soluble ink writing odor that is simple and can reduce the occupied volume.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

In the figure, reference numeral 1 denotes a cylindrical writing body, a vent hole 20 is provided in the tapered part at the front end, and a holder iron insertion hole 2 is provided in the tip of the tapered part 7.

Further, the rear end portion 3 is closed. Reference numeral 4 denotes an ink reservoir inserted into the main body 1 of the writing instrument over almost its entire length, the rear end 5 of which is closed, and a holder 6 iron-coupled to the front end thereof.

A stepped core hole with a large diameter at the front is bored on the axis of the holder 6.

The outer circumferential surface of the base body of the holder 6, which can fit properly with the ink reservoir 4, has an air intake part, an ink overflow part, an air guide part, and a large-diameter stop collar 8 from the rear to the front. It is formed.

The suction part consists of a fine spiral groove 9 with a narrow remaining bottom whose rear end fits in with the ink reservoir 4.

The ink overflow portion is provided with a large number of narrow, deep-bottomed parallel annular grooves 10 at slight intervals, and a large cross-sectional area guide groove in the wisteria line direction at an appropriate location on the outer peripheral surface, the rear end of which is connected to the spiral groove 9. 1
1, and on the opposite side of the guide groove 11 in the radial direction, a suction groove 12 is carved, which has an extremely small width in the circumferential direction, whose inner end reaches the core hole 7, and which is quite long in the axial direction. It is formed by

The air guide section has a plurality of annular grooves 13 of slightly large size (appropriate size that does not exhibit capillary action) lined up front and back, and the annular groove 13 at the rearmost position, the front end of the guide groove 11, and each groove. The annular grooves 13 and the frontmost annular groove 13 and the front part of the stop ring 8 are formed by having notch holes 14 provided at different positions in the circumferential direction to communicate with each other.

The cross-sectional area of the spiral groove 9, the width of the parallel ring 10, and the width of the suction groove 12 in the circumferential direction are all determined so that the ink can be sucked by capillary action. Specifically, the cross-sectional area and length of the spiral groove 9 are set such that, in a static state, the ink in the ink reservoir 4 is sucked by capillary action, and the front surface of the ink stops in the middle of the spiral groove 9. It is stipulated in The capillary force in the parallel annular groove is larger than the capillary force in the spiral groove 9, and is equal to or greater than the capillary force in the suction groove 12. Further, the capillary force due to the suction groove 12 is larger than the capillary force around the ink guide wick 19 inserted into the core hole 7 of the holder 6 (in case the guide wick is made of fiber, the capillary force itself).

The dimensions of the ink guide core 19 are determined so that when the ink in the ink reservoir 4 expands, the excess ink is sent to the ink overflow portion without passing through the spiral groove 9.

A holding cylinder 16 is formed in front of the base portion of the holder 6 via a tapered portion 15 .

A tip cylinder 18 is fixedly mounted inside the holding cylinder 16 and supports a ball 17 at its tip.

In this embodiment, the ink guide core 19 is made of a solid body,
Its front end is located at the front end of the tip cylinder 18, and its rear end slightly protrudes from the rear end of the holder 6 and enters into the ink reservoir 4.

In the above embodiment, when it is inconvenient, some of the ink in the storage cylinder 4 is sucked into the spiral groove 9 due to the capillary action of the spiral groove 9 to a position where its forward movement force disappears, and outside air enters the storage cylinder 4. It is preventing the influx to. As writing progresses, the ink in the ink cylinder 4 decreases and the pressure inside the storage cylinder 4 decreases, and outside air flows in through the ventilation hole 20, passes through the notch hole 14, the annular groove 13, and the guide groove 11, and The ink in the spiral groove 9 is pushed back and flows into the ink reservoir 4, thereby compensating the air pressure inside the reservoir 4.

Furthermore, when the ink or air in the reservoir 4 expands due to body temperature or other influences during writing, the ink will be removed by the spiral groove 9.
It passes around the guide core 19, which is easier to flow than the core hole 7, and overflows into the suction groove 12 from the core hole 7, and is stored in the parallel annular groove 10.

Furthermore, although excess ink flows into the guide book 11, the dimensions of each part are determined so that it never completely blocks the guide groove 11. Therefore, excessive ink is supplied to the tip of the conductive core 19 and the ink never drips out from around the ball 17.

The ink accumulated in the suction groove 12, the parallel annular groove 10, and the guide groove 11, which are ink overflow areas, is caused by capillary phenomenon as you write.
It is supplied around the guide core 19 through the suction groove 12,
It gradually decreases.

In addition, each annular groove 13 has a notch hole 14 located at a different position from each other, so that even if the ballpoint pen is turned downward or shaken with ink accumulated in the ink overflow part, , the ink in the ink overflow area will not flow out from the tip.

In the present invention, in the static calendar state, the ink in the ink reservoir 4 is sucked by capillary action over a certain length at the rear of the spiral groove 9 serving as the suction section, but the ink in the ink reservoir 4 expands. However, the surplus ink does not pass through the spiral groove 9, but instead flows into the ink overflow part.
Since the capillary force of the helical groove 9 is larger than that of the helical groove 9, the ink in the ink overflow portion is not sucked into the helical groove 9.

That is, in any case, only a certain amount of ink is sucked into the rear part of the spiral groove 9, and the front part of the spiral groove 9 always remains in a void state. When the air pressure inside the ink reservoir 4 decreases, the outside air removes the ink at the rear of the spiral groove 9 and is easily sucked in, allowing smooth writing.

In addition, in the present invention, since the spiral groove 9 acts as a valve for intake of outside air, the length in the spiral direction can be made significantly smaller than the actual length of the groove. This is convenient for downsizing.

Note that the present invention also applies to those in which the conductive core is made of fiber.
Needless to say, it is applicable.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal sectional front view showing an example in which the present invention is applied to a ballpoint pen, FIG. 2 is a longitudinal sectional view taken along the 0-Ro line in FIG. 1, and FIG. Line longitudinal section, 4th
The figure is also a longitudinal sectional view taken along the line W-N, and FIG.
It is a vertical cross-sectional view taken along the V line. 1...Main body, 2...Holder unit insertion hole,
3... Rear end portion, 4... Ink reservoir, 5
...Rear end, 6...Holder, 7...
... Core hole, 8 ... Stop tsuba, 9 ...
Spiral groove, 10...Parallel annular groove, 11...
Guide groove, 12... Suction groove, 13... Annular groove, 14... Notch hole, 15... Bupa part, 1
6...Holding cylinder, 17...Pole, 18...
Chip cylinder, 19...Ink guide core, 20...Vent hole. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. In a low-viscosity ink writing instrument configured to supply ink from an ink reservoir to a writing end via a guide core, a rear end is attached to the rear end of the outer peripheral surface of a holder that holds the guide core. is provided with a spiral groove that communicates with the ink storage portion, and in front of the spiral groove is provided a number of parallel annular grooves with a narrow width and deep bottom, and at appropriate locations on the outer circumferential surface thereof, the rear end is connected to the spiral groove, and the front end is a spiral groove. An axial guide groove with a large cross-sectional area that connects with the outside air is provided, and an axial suction groove with an extremely small circumferential width and an inner end reaching the core hole for holding the guide core in the holder is provided at a suitable location on the outer circumferential surface. A groove is provided, and the dimensions of the helical groove are determined so that when the ink is left at rest, the ink in the ink reservoir is sucked halfway through by capillary action, and the capillary force of the parallel annular groove is the capillary force of the suction groove is equal to or smaller than the capillary force of the parallel annular groove and greater than the capillary force in the ink reservoir of the guide wick, and the dimensions of the guide wick are: A low-viscosity ink writing instrument characterized in that when the ink in the ink reservoir expands, surplus ink is sent forward through the guide core without passing through the spiral groove. 2. The low-viscosity ink writing instrument according to claim 1, wherein the guiding core is a solid body. 3. The low-viscosity ink writing instrument according to claim 1, wherein the guiding core is fibrous. 4 Slightly large and complex annular grooves lined up front and back in front of the guide groove are provided, and the rearmost annular groove and the front end of the guide groove, each annular groove with each other, and the frontmost annular groove and the front part, The low-viscosity ink writing implement according to any one of claims 1 to 3, wherein each of the low-viscosity ink writing implements communicates with each other through notch holes provided at offset positions in the circumferential direction.