JP3334372B2 - Writing implement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink tank for storing ink in a free state and a pen point member, which is elastically deformed by a sliding force of a pressing member slidable in a longitudinal direction. The present invention relates to a writing instrument having a valve member that opens and closes an ink passage.

[0002]

2. Description of the Related Art A writing implement of the type called a so-called raw ink type writing implement which stores ink in a free state without providing an ink holding member such as a batting inside an ink tank has the advantage that a large amount of ink can be stored. On the other hand, there is a problem that ink must be strictly controlled to supply the ink to the pen tip, and ink leakage or writing marks may easily occur.

As an example of a writing implement provided with a valve mechanism between an ink tank and a pen tip, Japanese Patent Application Laid-Open No. 6-24195 discloses a notch made of an elastic material, which receives a pressing force due to sliding of the pen tip, and There has been disclosed a writing implement having a valve member that opens an ink passage in the shape of a circle and contracts elastically when the pressing force is released to close the ink passage.

[0004]

In the apparatus disclosed in the above-mentioned publication, unnecessary outflow of ink due to variations in the locking position of the pressing member, the positional relationship between these and the valve, and the maximum opening area is suppressed. It was difficult to do. Therefore, in order to control ink leakage and ink dropping while satisfying the abundant ink supply during writing, which is an advantage of raw ink type writing implements, it is necessary to strictly control the dimensions and positional relationship of parts There was also a problem with productivity.

[0005]

That is, according to the present invention, a sliding force is exerted by a pressing member slidable in a longitudinal direction between an ink tank accommodating ink in a free state therein and a pen tip member. In a writing instrument having a valve member that opens and closes an ink passage by being elastically deformed, a maximum opening area of an ink tank side opening portion of the ink passage of the valve member may be an opening portion on a pen tip side. The writing implement is characterized in that the writing implement is smaller than the maximum opening area.

[0006]

The flow rate of ink from the ink tank to the pen tip is greatly affected by the opening area of the ink passage in the valve member. The opening of the ink passage differs mainly between the opening on the ink tank side and the opening on the pen tip side. The opening on the ink tank side contributes to liquid tightness when the ink passage is closed, and the opening on the pen tip side contributes to ink supply when the ink passage is opened. By making the maximum opening area of the pen tip side relatively large, it is possible to supply abundant ink, which is the original advantage of raw ink type writing implements, and to make the maximum opening area of the ink tank side opening relatively small. Thus, the liquid tightness when the ink passage is closed can be ensured. In addition, the amount of ink circulation is
At the appropriate position of the ink passage that gradually decreases in diameter toward the ink side.
Ink distribution due to dimensional variations, etc.
Minimizing fluctuations in quantity and ensuring high productivity and stable quality
Things can be supplied.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The writing implement A in FIG. 1 uses the inner hole 2 of the barrel 1 as an ink tank as it is, and is an example of a so-called disposable raw ink type writing implement. A pen point holder 3 is press-fitted and fixed to the tip of the barrel 1, and is prevented from falling off by a projection 4 formed on the inner wall of the barrel 1. In addition, shaft cylinder 1
In order to prevent ink from leaking between the inner wall of the pen tip holder 3 and the pen tip holder 3, an outer circumferential rib 3a having a comb-like cross section is formed on the outer periphery of the pen tip holder 3, and an air passage is formed in a part thereof. Is formed.

A pen tip 5 is slidably mounted in the center hole of the pen tip holder-3. The pen tip 5 comes into contact with a valve member 7 made of an elastic synthetic resin such as silicone rubber, butyl rubber, polyethylene, or polypropylene.
In other words, the pen tip 5 moves toward the ink tank when a slight pressing force such as a pen pressure is applied, and when the pressing force is released, the pen tip 5 moves forward because it is biased forward by the elastic force of the valve member 7. Since the stepped locking portion is formed in the center hole of the pen tip holder 3, the pen tip 3 is prevented from falling off. Also,
The rearward movement of the valve member 7 is prevented by a step-like locking portion formed on the inner wall of the shaft cylinder.

Here, the valve member 7 comprises a fixed leg portion 7a for the barrel 1 and a flat deformed portion 7b in which a cut-shaped ink passage 7c is formed. When a pressing force such as a pen pressure is applied to the pen tip 5, the pen tip 5 moves toward the ink tank and presses the deformed portion 7b of the valve member 7. The deformed portion 7b is elastically deformed by the pressing force and opens the ink passage 7c. Here, by setting the contact relationship between the pen tip 5 and the valve member 7, the ink passage 7c is opened simultaneously with the movement of the pen tip 5, or the ink passage is not reached until the pen tip 5 reaches a certain point. Whether or not 7c is opened can be appropriately set.

As shown in FIG. 2, which is an enlarged cross-sectional view of the portion I in FIG. 1, the pen tip 5 has a step 5a at the rear end thereof, and a reduced diameter portion 5b is formed. The end surface of the reduced diameter portion 5b is a pressing portion 5c against the valve body, and presses the deformed portion 7b of the valve member 7 as the pen tip 5 slides to open the ink passage 7c.

As shown in FIG. 3, which is an enlarged sectional view of the portion I in FIG. 1 viewed from the direction II, the ink passage 7c gradually moves from the opening 7d on the pen tip side toward the opening 7e on the ink tank side. It is formed so as to reduce the diameter. That is, the maximum opening area of the opening 7e on the ink tank side is smaller than the maximum opening area of the opening 7d on the pen tip side when the ink passage 7c is opened under the pressing force of the pen tip 5. is there. Here, by making the maximum diameter of the opening 7d on the pen tip side smaller than the diameter of the reduced diameter part 5b of the pen tip 5, the reduced diameter part 5b is immersed in the opening 7d. It is possible to suppress a phenomenon in which the ink passage is not blocked.

In FIG. 3, the ink passage 7c is tapered from the pen tip side opening 7d toward the ink tank side opening 7e in a tapered shape. The diameter may be reduced stepwise by a part or may be reduced to a curved surface. As a method of forming such an ink passage 7c, various methods such as a method of cutting with a blade or a method of forming at the time of molding can be adopted.

FIGS. 4 and 5 show other examples.
It is shown as a drawing corresponding to FIG. 3 of the above example. FIG.
Is an example in which the valve member 7 is made of a plurality of members (two members). The ink passage 701d formed in the valve member 701 on the pen tip side has a larger diameter than the ink passage 702e formed in the valve member 702 on the ink tank side. By doing so, the maximum opening area on the ink tank side of the ink passage is smaller than the maximum opening area on the pen tip side of the entire valve mechanism. An end of the valve member 702 on the ink tank side is provided with a flange 702 for attachment to the valve member 701 on the pen tip side.
f is formed, and when mounting the valve members in the writing instrument, the respective valve members may be connected to each other. Also,
The valve members may be fixed with an adhesive or the like.

Although not shown, when a two-member valve mechanism is used, the deformed portion of the valve member on the pen tip side is replaced with the deformed portion of the valve member on the ink tank side in addition to the example shown in FIG. By making the pen-tip-side valve member relatively softer than the ink-tank-side valve member, the ink passage closes when the pen-tip-side valve member is closed (opens). Force required for the ink tank) and the maximum opening area of the ink passage on the ink tank side can be made smaller than the maximum opening area on the pen tip side as in the above-described example.

FIG. 5 shows a deformed portion 7 of the valve member 7.
The opening of the ink passage 7c is controlled by devising a method of deforming b. In other words, a space 5d is formed at the center of the rear end of the pen tip 5, and the pressing portion 5c for the valve member 7 is located farther from the ink passage 7c to be the outer peripheral portion of the pen tip 5, so that the pen tip 5 slides. When moving, a relatively outer peripheral side of the deformed portion 7b is pressed, and an inner protrusion 6 as a deformation restricting portion of the deformed portion 7b is formed in the inner hole 2 of the shaft cylinder 1 on the ink tank side, so that an ink passage is formed. At a position relatively close to 7c, retraction of the deformed portion around the ink passage is restricted. By doing so, the deformed portion 7b
Is the pressing portion 5c of the pen tip 5 with respect to the sliding amount of the pen tip 5.
The amount of deformation is large on the outer angle side contacting with the ink passage, but the amount of deformation is small in the vicinity of the ink passage 7c due to the inward protrusion 6 of the inner hole 2, which is due to the opening 7d on the pen tip side of the ink passage 7c and the ink tank side. This also affects the deformation of the opening 7e, so that the maximum opening area on the ink tank side can be made smaller than the maximum opening area on the pen tip side.

Various modifications can be made without departing from the gist of the present invention. To give an example, the ink tank has a slide stopper that moves as the amount of ink decreases, the internal space decreases, and a vent that communicates with the ink tank, and takes in air as the ink is consumed. Such a cartridge may be used, or a cartridge-type writing instrument provided with an exchangeable ink tank may be used. As shown in FIG. 1, the pen tip 5 may be formed by forming a fiber converging body of acrylic fiber or polyester fiber into an appropriate shape, or a synthetic resin pen tip having an ink passage formed therein. Alternatively, a small tubular nib having a hard cylindrical body and a needle as a nib, or a ball nib with a hard ball rotatably held in a tip may be used. Further, the ink passage 7c of the valve 7 is opened by sliding the pen tip 5, but another member for communicating the pressing force (sliding force) is interposed between the pen tip 5 and the valve 7. Alternatively, a dedicated pressing member may be provided to the valve 7 without sliding the tip of the pen, for example, a rear-end knock-type writing instrument.

[0017]

As described above, the writing instrument according to the present invention receives the sliding force of the pressing member slidable in the longitudinal direction between the ink tank containing the ink in the free state and the pen tip member. In a writing instrument having a valve member that opens and closes an ink passage by elastically deforming the ink passage, the maximum opening area of the ink tank side opening portion of the ink passage of the valve member has an opening on the pen tip side. The maximum opening area of the portion is made smaller, so that the outflow of excess ink and the shortage of outflow ink can be suppressed as much as possible with a simple structure.

[Brief description of the drawings]

FIG. 1 is a cutaway sectional view of a main part showing an embodiment.

FIG. 2 is an enlarged sectional view of a portion I in FIG.

FIG. 3 is an enlarged cross-sectional view of part I of FIG. 1 viewed from a direction II.

FIG. 4 is equivalent to a portion I in FIG. 1 showing another embodiment.

FIG. 5 is equivalent to a portion I of FIG. 1 showing still another embodiment.

[Explanation of symbols]

 A Writing implement 1 Shaft cylinder 2 Inner hole 3 Pen tip holder 3a Entire rib 3b Slit 4 Convex part 5 Nib 5a Step 5b Reduced diameter part 5c Press part 5d Space 6 Inward convex part 7 Valve member 7a Fixed leg part 7b Deformation part 7c Ink passage 7d Opening 7e Opening 701 Valve member 701d Opening 702 Valve member 702e Opening 702f Mounting flange

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B43K 5/00-8/24

Claims (1)

(57) [Claims] 1. An ink passage between an ink tank accommodating ink in a free state and a pen point member, which is elastically deformed by a sliding force of a pressing member slidable in a longitudinal direction. In a writing instrument having a valve member that opens and closes, a maximum opening area of an ink tank side opening portion of an ink passage of the valve member is smaller than a maximum opening area of a pen tip side opening portion. Writing implements.