JPH025991Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention has an ink tank that directly stores ink without occluding it in batting, etc., and the air inside the ink tank expands due to factors such as temperature rise. To improve a cap of a writing instrument equipped with an ink reservoir for temporarily storing ink pushed out from an ink tank when the ink is pressed out from the tip of the brush or from the air hole.

(Prior art) Barrel 1 and cap 2 of a conventional writing instrument of this type
The fitting structure is as shown in FIG. That is, the interior of the cap 2 is provided with a part that fits tightly against the barrel 1, such as an inner cap 3, which seals the brush tip 4 and the air hole 5 from the outside air and prevents the brush tip 4 from drying and air from the air hole 5. Prevents ink evaporation.

(Problems to be Solved by the Invention) In the conventional structure described above, when the cap 2 is fitted with the brush tip 4 facing down, the shaft tube 1 will be slightly closed even after its outer surface comes into close contact with the inner surface of the middle cap 3. Since the inner cap 3 is press-fitted and fixed by a distance of The amount of ink overflows and is stored in the ink reservoir 6. Conversely, when the cap 2 is removed from the shaft cylinder 1, the air inside the middle cap 3 will be depressurized, contrary to the above phenomenon, and therefore some of the ink in the ink tank will be drawn out and the ink reservoir 6 will be removed. will be stored in As described above, each time the cap 2 is attached or detached, the amount of ink stored in the ink reservoir 6 increases, and eventually the storage capacity is exceeded and ink is blown out from the air holes 5.

The object of the present invention is to provide a writing instrument cap that overcomes the drawbacks of the conventional products.

(Means for Solving the Problems) The present invention solves the above-mentioned problems by providing a cap attached to the barrel of a writing instrument using an ink direct storage system in which an ink reservoir is attached to an ink tank. When attached to the cylinder, inner diameter reducing protrusions are provided on the inner surface corresponding to the front and rear sides of the air hole of the shaft cylinder to tightly isolate the air hole by closely contacting the surface of the shaft cylinder, and a cap is attached to the top or side surface. The present invention provides a cap for a writing instrument, which is provided with a ventilation hole that communicates the inner hole with the outside, and further includes a non-water-absorbing elastic material inside the top surface of the cap, which completely immerses and shields the tip of the writing instrument. be.

(Function) The present invention prevents the air compression or depressurization phenomenon that occurs in conventional structures when the cap is attached or detached by providing a vent on the top or side surface of the cap that communicates the inner hole of the cap with the outside. However, by providing a ventilation hole, the drying of the tip of the brush and the evaporation of ink from the air hole can be prevented by using a non-water-absorbing elastic material that completely immerses the tip of the brush and shielding it from the air hole. This is achieved by an inner diameter reducing protrusion on the inner surface of the cap that is in close contact with the barrel surface.

(Example) FIG. 1 is a longitudinal sectional view showing an example of the present invention. The barrel 1 of the writing instrument main body has an ink tank 7 inside its rear end, and in front thereof has a large number of circumferential grooves 8 on its outer surface, and an axial longitudinal groove 9 that communicates each of the circumferential grooves 8. A storage body 6 is installed inside.
The front end of the ink reservoir 6 protrudes from the front end of the barrel 1, and an air hole 5 is provided at the boundary between the protrusion 10 and the barrel 1 to communicate the inside of the ink reservoir and the outside of the barrel. . A mouth plug 13 holding a chip 11 is press-fitted into the front end of the protrusion 10 of the ink reservoir 6, and the chip 11 is inserted into an axial vertical hole 13 provided at the center of the ink reservoir 6. It is connected to the ink guide rod 14. In normal writing conditions, ink is supplied from the ink tank 7 to the tip 4 of the tip 11 via the ink guide rod 14.
If excessive ink flows out due to the replacement of air with the ink in the ink tank 7 consumed during writing, or the expansion of the air in the ink tank due to a rise in temperature, etc., the ink flows through the overflow hole at the rear end of the ink reservoir 6. 15 and is temporarily stored in each circumferential groove 8 through the communication groove 9. When the cap 2 is attached to the barrel 1, the inner surface of the barrel 1 corresponds to the front and rear sides of the air hole 5 of the barrel 1 (more precisely, the protruding portions 10 of the barrel 1 and the ink reservoir 6). A pair of inner diameter reducing protrusions 16 are provided which are in close contact with the surface of the inner diameter. This protrusion 16
Therefore, the air hole 5 is airtightly isolated from the inside and outside of the cap 2. A cylindrical portion 18 having an inner surface stepped portion 17 is protruded from the inside of the top end surface of the cap 2, and a non-water-absorbing cylindrical elastic body 19 is attached to the inner surface stepped portion of the inner hole. The position of the elastic body 19 is set at such a position that when the cap 2 is attached to the barrel 1, the brush tip 4 can reach the tip surface 20 and completely immerse therein. Vent holes 21 are provided at upper and lower positions on the outer circumferential portion of the cylindrical portion 18, opening at the top end surface of the cap 2 and communicating the inside of the cap 2 with the outside air. Therefore, when the cap 2 is attached to the barrel, the inside of the cap is in communication with the outside air, but the brush tip 4 and the air hole 5 inside the cap are hermetically sealed by the elastic body 19 and the protrusion 16, respectively. maintain.

(Effects of the invention) The present invention has the above-mentioned structure and function, and since the internal space of the cap is communicated with the outside through the vent, the air inside the cap is compressed or vice versa when the cap is attached or detached. Since the phenomenon of pressure reduction is eliminated, ink is prevented from accumulating in the ink reservoir, and an accident in which ink exceeding the ink storage capacity of the ink reservoir is blown out from an air hole or the like is prevented. However, even though the inside of the cap communicates with the outside, the tip of the brush is sealed by an elastic body and the air hole is sealed by a protrusion, so the drying of the tip and the evaporation of ink from the air hole are prevented. Preventive measures have been taken and the cap's functionality will not be impaired in the slightest.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention;
The figure is a longitudinal sectional view showing a conventional example. 1...Shaft cylinder, 2...Cap, 3...Medium cap, 4
... Brush tip, 5... Air hole, 6... Ink reservoir, 7...
Ink tank, 8... Circumferential groove, 9... Vertical groove, 10... Protrusion, 11... Chip, 12... Mouth plastic, 13... Vertical hole,
DESCRIPTION OF SYMBOLS 14... Ink guide rod, 15... Overflow hole, 16... Projection, 17... Inner surface step, 18... Cylindrical part, 19... Elastic body, 20... Tip surface, 21... Vent hole.

Claims (1)

[Scope of utility model registration request] When the cap is attached to the barrel of a writing instrument using an ink direct storage method in which an ink reservoir is attached to the ink tank, the cap is placed on the inner surface corresponding to the front and back positions of the air holes of the barrel when the cap is attached to the barrel. In addition to providing an inner diameter reducing protrusion that adheres closely to the barrel surface to airtightly isolate the air hole, a vent hole is provided on the top or side surface to communicate the inner hole of the cap with the outside, and a writing instrument is provided inside the top surface. A writing instrument cap that is made of a non-water-absorbing elastic material that completely immerses and shields the tip of the writing instrument.