JPH0742793Y2 - Writing cap attachment structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a cap mounting structure for a writing instrument in which a cap is pressure-fitted to a main body of a pen tip such as a small-tube writing instrument or a ballpoint pen that projects from the tip.

(Prior Art) As a method of mounting the cap on the main body, there are a method of screwing and a method of pressure fitting. There are two types of press-fitting, one is press-fitting in which press-fitting is performed, and the other is concave-convex fitting in which both the cap and the main body are fitted concavely. This pressure-fitting type has recently been widely used because it has a simple operation such that the cap can be attached and detached by pushing or pulling the cap in the mounting direction, and it is easy to mass-produce as a synthetic resin injection molded product. There is.

On the other hand, however, there is a drawback that the mounting force tends to vary greatly due to the variation in the dimensions of the cap and the main body compared to the case of screwing.By selecting a material that exhibits elasticity, this drawback becomes apparent. It is restrained from doing.

(Problems to be Solved by the Invention) The above-mentioned drawback is certainly convenient if a material capable of exhibiting elasticity can be selected for both the cap side and the body side, but sometimes causes other problems. One of them is
It means that the pen tip is not fixed enough, and if you select a member that projects the tip of the pen tip on the main body side, for example, a material such as the tip holder or the front shaft, that can exert sufficient elasticity, This elasticity is also exerted for fixing the pen tip, which is convenient for making the writing feel soft, but the elasticity becomes too strong, and the nib fixing itself becomes unstable. For example, when it is used by being attached to a machine such as a plotter, the handwriting may be disturbed.

(Means for Solving the Problem) The present invention provides a cap mounting structure for a writing instrument, in which a cap is mounted by pressure fitting to a main body with a pen tip protruding from the tip. A cap mounting structure of a writing instrument is provided, in which a cap fitting portion is provided, and a concave portion that makes mounting of a pen tip and cap mounting independent is provided between both portions of this member.

(Embodiment) FIG. 1 attached shows a first embodiment. Reference numeral A indicates a main body, and reference numeral B indicates a cap. The main body A of this example is an example of a small-tube writing instrument, that is, the main body A has the tip holder 2 press-fitted and fixed to the tip of the barrel 1, and the tip of the tip holder 2 is made of metal, ceramic, or the like. The small tube 3 is projected, and the needle body 4 is inserted into the small tube 3 with its rear end fixed by a weight 5. Incidentally, reference numeral 6 denotes a temporary ink reservoir member generally called bellows having a temporary ink reservoir groove having a comb-shaped vertical cross section, and reference numeral 6 denotes a gap between the shaft cylinder 1 and the chip holder 2. Is an air passage formed as.

Further, the chip holder 2 is an annular recess for mounting the cap B.
It has a recess 2a and a recess 2b. That is, in this example, the member used for mounting with the cap is this chip holder 2, and the recessed portion 2b has a thin material portion forming the annular recessed portion 2a to improve material elasticity. In addition, the pen tip 3 is fixed regardless of the elasticity.

On the other hand, the cap B has an appropriate number of protrusions 7a formed on the wall surface of the inner hole 7. In the state shown in the figure, the convex portion 7a is fitted into the annular concave portion 2a of the chip holder 2. That is, the example of the present example shows one example of the press-fitting by the concave and convex fitting.

Based on the above, in the present example, it is desired that the tip holder 2 securely fixes the small tube 3. Therefore, a relatively hard material is selected as the material of the chip holder 2. On the other hand, a relatively soft material is selected as the material of the cap B. Here, in consideration of the elasticity exerted by the recessed portion 2b and the elasticity exerted by the shape of the cap B, an appropriate material such as nylon, polyethylene, polypropylene, polyacetal, polycarbonate, AS resin, ABS resin may be selected. However, as a specific example, when polyacetal is selected as the tip holder 2 and polypropylene is selected as the cap B, the ink passing through the inside of the wall of the cap B is not used even when the tip of the pen tip 3 is not sealed as shown in the figure. It is preferable since it is possible to sufficiently suppress the permeation loss. Reference numeral C is a contact portion between the main body A and the cap B, which is provided for the purpose of producing a pleasant sound of "squash" and for ensuring the airtightness.

Next, FIG. 2 shows a second embodiment.

In this example, the annular recess 2a of the chip holder 2
The formed meat portion projects forward from the fixing meat portion of the pen tip 3. The elasticity of the annular concave portion 2a when the cap B is attached can be further exerted. In the case of a general writing instrument that is held in the hand, it is preferable to attach it to a device such as a plotter, even if it is not preferable to make the pen tip 3 hard to see as in this example. In that case, since the visual writing is not necessary, it is possible to preferentially consider the exertion of elasticity.

Next, FIG. 3 shows a third embodiment.

In the case of this example, the annular recess 2a is provided in the chip holder 2
It is formed on the inner wall surface of the concave portion 2b. The cap B is mounted so as to apply a spreading force outward to the wall portion forming the annular recess 2a.

Although not shown, various other than the above, can be made. For example, the cap B may be composed of a plurality of members including an outer cap and an inner cap, and the protrusion 7a may be formed on the inner cap. Alternatively, the chip holder 2 may not be a member for mounting the cap. Instead, the tip of the barrel 1 can be used for mounting the cap, the shape of the recessed portion 2b can also be formed so as to be recessed in an annular shape, or can be appropriately formed as a plurality of types. Also, instead of using a small-tube writing instrument, for example, a ball-point pen body using a cylindrical metal tip, or using a synthetic resin extruded product nib fixed to a hard tubular tip is used. In addition, as a type of writing instrument, it can be a type generally called a batting type writing instrument having a built-in ink absorber, and a sealing member for sealing the tip of the pen tip 3. Then, for example, a spherical member can be used. The press-fitting may be other than the concave-convex fitting, for example, press-fitting.

(Effect of the Invention) A pen tip mounting portion and a cap fitting portion are provided in one member of the main body, and a recessed portion that separates the pen tip mounting and the cap mounting is provided between these portions of this member. Therefore, it is possible to securely fix the pen tip and securely attach the cap while using one member.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part showing a first embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view of an essential part showing a second embodiment, and FIG. 3 is a longitudinal sectional view of an essential part showing a third embodiment. A ... Main body, B ... Cap, C ... Abutment between main body and cap, 1 ... Shaft cylinder, 2 ... Chip holder, 2a ...
Annular recess, 2b ... recess, 3 ... pen tip, 4 ... weight,
5 ... Temporary ink reservoir member, 6 ... Air passage, 7 ...
Inner hole of cap, 7a ... Protrusion.

Claims (1)

[Scope of utility model registration request] 1. A cap mounting structure for a writing instrument, wherein a cap is mounted by pressure fitting to a main body having a pen tip protruding from the tip, and a pen tip mounting portion and a cap fitting portion are provided in one member of the main body, Also, between these two parts of this member,
A cap mounting structure for a writing instrument, which is provided with a concave portion that makes it possible to attach the pen tip and mounting the cap independently.