JP2509396Y2 - Writing instrument - Google Patents

Description

[Detailed Description of the Invention] (Industrial application) Ink tank based on changes in temperature and atmospheric pressure when supplying ink stored in an ink tank to a pen tip regardless of raw ink state, that is, without relying on capillary force In order to suppress excess or deficiency of ink supply due to volume change of the air inside, a member that temporarily stores ink between the ink tank and the pen tip, and a temporary ink reservoir with a comb-shaped vertical section is provided. The present invention relates to a writing instrument in which an item that the user has is interposed.

(Prior Art) The above-described writing instruments are used in many writing instruments such as fountain pens, small tube writing instruments, and makeup instruments. In recent years,
Applications are expanding, such as for automatic drafting machines such as plotters. The certainty of the function is required as much, and various measures are taken to prevent the ink from leaking unnecessarily from the barrel.

One of them is to increase the gap between the inner wall of the shaft cylinder and the temporary ink reservoir groove of the temporary ink reservoir member toward the front. The idea is to suppress the leakage of ink that has passed through the inner wall of the shaft cylinder by a capillary action. Here, since it is preferable that the temporary ink reservoir member can store a larger amount of ink in the rear temporary ink reservoir groove, the diameter of the temporary ink reservoir groove may be designed to be smaller toward the front. There is also a product that satisfies the above-mentioned relationship of the gap by utilizing this shape.

(Problems to be solved by the invention) Satisfying the relationship that the gap between the inner wall of the shaft cylinder and the temporary ink reservoir groove of the temporary ink reservoir member becomes larger toward the front, in itself, means that the gap becomes larger toward the front. Whether or not it is continuous, or whether the inner wall of the barrel itself is a large diameter hole, a constant diameter hole, or a small diameter hole toward the front. Is desirable regardless of. However, even if this relationship is satisfied, it is not always possible to sufficiently suppress the leakage of the ink transmitted through the inner wall. For example, in the case of an automatic drafting machine pen exclusively used for vertical writing, there is also a compulsory leakage of ink due to vertical movement in contact with the writing surface. In some cases, it is not enough to consider static relationships.

(Means for Solving the Problems) In the present invention, a temporary ink reservoir member having a temporary ink reservoir groove having a comb-shaped vertical cross section whose diameter becomes smaller toward the front is provided with an inner wall of a barrel and a temporary ink reservoir groove. And a large gap that breaks the relationship of the gap that increases toward the front by forming an annular recess in the portion of the inner wall of the barrel that corresponds to the gap that increases toward the front. The writing instrument formed by forming the.

(Operation) The gap between the inner wall of the shaft cylinder and the temporary ink reservoir groove becomes front and rear from the annular recess of the shaft cylinder inner wall, from the rear to the front, wide from the narrow rear to the recess, and narrows. Then, the relationship of reaching the front of the recess is formed.

From the narrow rear side to the widening side of the concave portion, the above-described relationship that the ink leakage is suppressed by the capillary action is satisfied. Further, this relationship is the same as that when a step portion is formed in which the inner side wall of the shaft cylinder has a large diameter hole on the front side. However, if there is ink that goes beyond this relationship and moves further forward, if a step is formed, it will simply move forward, but in the case of a recess, It becomes a pool at the recess. When the ink that collects moves forward, it becomes larger than the thin film or small drops that form the accumulated ink, so there is a possibility of contact with the temporary ink reservoir groove. It will be expensive. Upon contact with the temporary ink fountain groove, the ink moves to the temporary ink fountain groove. Further, for example, when such a forward movement is attempted to occur when the above-described vertical movement is occurring, the ink receives resistance from the front side of the wall surface forming the recess. Upon receiving, at least a part of the ink is given a movement toward the inside of the barrel. Since there is a temporary ink reservoir member, the ink moves to the temporary ink reservoir groove.

Even if not all the inks go through the above-mentioned state, the ink leakage due to the presence of the recesses is suppressed.

(Example) An example is shown in the attached FIG. 1 and FIG. Reference numeral 1 indicates a shaft cylinder, which has an ink tank 3 integrally formed by a tail plug 2. Reference numeral 4 indicates an ink guiding core body made of a fiber converging body, a ceramic communicating porous body or the like, and extends from the ink tank 3 through the central hole of the temporary ink reservoir member 5 to the pen tip body 6. The tip 6 of the pen tip 6 projects from a tip holder 7 which is inserted and fixed to the front end of the barrel 1 by press fitting or the like. In the case of normal writing, the ink guide core 4
The ink is supplied from the ink tank 3 to the pen tip body 6 by. The pen tip body 6 shown in the figure is a pen tip body of a small tube type writing instrument composed of a small tube and a needle body, but it is generally called a resin pen obtained by extrusion molding synthetic resin,
It may be a pen tip of an appropriate writing instrument such as a ballpoint pen, a fountain pen, a writing brush, or a makeup tool such as an eyeliner, a lip color, or a nail color. Further, since various preferable embodiments of the temporary ink reservoir member 5 are already known by many conventional techniques, the description of the function-related portion will be omitted, but in FIG. 2, reference numeral 5a indicates a temporary ink reservoir groove. In addition to the above, in this example, a small diameter portion is shown on the front side in the slightly rear side of the center.

A flange portion 8 is formed on the outer wall of the shaft cylinder 1. Based on the above, an automatic drafting machine pen such as a plotter is a suitable target, and this is an example. In this example, the recess 9 is formed in the inner wall of the barrel 1 at the flange 8. Has been formed. It is formed in a circumferential shape. In this example, the reason why the concave portion 9 is formed at the collar portion 8 is shown because of advantages in molding. That is, when the shaft cylinder 1 is obtained as an injection-molded product of a synthetic resin such as polyethylene, polypropylene, nylon, or polyacetal, when the collar portion 8 is integrally formed, a recess is often formed inside the collar portion. There is. It is not necessary to prepare a mold having a shape corresponding to the recess. It is shown that forming a circumferential recess by injection molding imposes an unreasonable force, which is originally unfavorable in terms of molding. Therefore, it is shown that such a use can be achieved, and the collar portion 8 is a device. Since it is used for attachment to the main body, it is a portion that is easily affected by impact, and is also a portion that is convenient for forming the recess. Of course, the collar portion 8 can be formed as a separate body having an appropriate shape from the shaft cylinder 1, and it is not impossible that the collar portion 8 can be screwed instead of the collar portion when being attached to the apparatus main body.

Further, the boundary between the small diameter portion on the front side and the large diameter portion on the rear side of the temporary ink reservoir member 5 is located at the recess 9. At this boundary of the temporary ink reservoir member 5, the size of the gap with the inner wall of the barrel 1 suddenly changes. This is used. The ink can be made into sufficiently large drops. Reference numeral 10 is an elastic ring for preventing unnecessary leakage of ink from the ink tank 3, 11 is a cap, and 12 is a sealing elastic ring disposed inside the cap 11.

Next, another example is shown in FIG. In the temporary ink reservoir member 5 of this example, the diameter reduction toward the front is continuous rather than stepwise. Further, the inner wall of the barrel 1 has a larger diameter hole toward the front. Although they may be unclear in the state shown in the figure, the gap between the inner wall of the barrel 1 and the temporary ink reservoir groove 5a of the temporary ink reservoir member 5 is continuously increased toward the front due to the combination thereof. .. This example shows an example in which the shape of the temporary ink reservoir member 5 can be appropriately set. When the shaft cylinder 1 is obtained as an injection-molded product, when a slope generally called a draft taper is provided on the inner wall, the slope is forward. It specifically illustrates the use of what can be done.

Various other methods can be used. The shape of the recessed portion 9 is appropriate, and may be as shown in FIGS. 4 and 5, for example. FIG. 5 is also an example in which the recess 9 is formed by combining a plurality of parts. Further, the ink tank 3 may be a cartridge that is separately replaceable from the barrel 1 and may be appropriately replaced, or the barrel 1 may be composed of a plurality of parts such as a front shaft and a rear shaft.

(Effect of the device) A temporary ink reservoir member having a temporary ink reservoir groove having a comb-like vertical cross section whose diameter becomes smaller toward the front, and the gap between the inner wall of the shaft cylinder and the temporary ink reservoir groove becomes larger toward the front. The temporary ink is formed in such a manner that an annular recess is formed in a portion corresponding to a gap that increases toward the front of the inner wall of the shaft cylinder, and a portion with a large gap that breaks the relationship of the gap that increases toward the front is formed. A writing instrument that uses a reservoir member may be one that can strongly prevent ink leakage.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of the present invention, FIG. 2 is an enlarged view of a portion A of FIG. 1, and FIG. 3 is a view corresponding to FIG. 2 showing another example.
4 and 5 are views corresponding to FIG. 2 showing still another example. 1 ... Shaft cylinder, 2 ... Tail plug, 3 ... Ink tank, 4 ...
Ink guide core, 5 ... Temporary ink reservoir, 5a.
Temporary ink reservoir groove, 6 ... Nib, 7 ... Tip holder, 8 ... Collar, 9 ... Recess, 10 ... Elastic ring,
11 …… Cap, 12 …… Elastic ring.

Claims (1)

(57) [Scope of utility model registration request] Claim: What is claimed is: 1. A temporary ink reservoir having a temporary ink reservoir groove having a comb-like vertical cross section, the diameter of which decreases toward the front, and the gap between the inner wall of the shaft cylinder and the temporary ink reservoir increases toward the front. The writing instrument is formed in such a manner that the annular recess is formed in a portion corresponding to a gap that increases toward the front of the inner wall of the barrel, and a portion with a large gap that breaks the relationship of the gap that increases toward the front is formed.