JPH0444389Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sharp pencil whose lead is hard to break.

Knock-type sharp pencils and sharp pencils that automatically feed out the lead that decreases as you write are known, but if the lead is long and is dropped or handled roughly, the vibration may occur. The core may bend and break due to impact.

The present invention prevents such drawbacks and has various other features by attaching a core cap with an outer diameter smaller than the inner diameter of the shaft cylinder to the rear of the core, which prevents vibrations, shocks, etc. from acting on the core. Even if the core cap comes into contact with the inner surface of the shaft cylinder, it prevents the core from deflecting.
It can be made less likely to break.

This will be explained below along with examples.

In the figure, the shaft tube 1 and the cap 2 are fitted and attached to a connecting tube 3 formed at the rear of the cap.
It can be attached by screwing or other appropriate methods. A chuck means for gripping the lead 4 so as to withstand writing pressure is provided inside. Although a known knock-type chuck mechanism or the like may be provided as the knocking means, the drawing shows an automatic feeding mechanism configured to automatically feed out the lead as the writing is performed.

Although various known mechanisms can be applied to the automatic feeding mechanism, the structure shown in the figure is as follows. A slider 5 is fitted into a hole 6 at the tip of the base so as to be movable in the axial direction. The core guide pipe 8 is made of a synthetic resin material with a small frictional effect. As the material for the pipe, polyacetal resin, polyamide resin, fluorine resin, and other thermoplastic synthetic resin materials having a low coefficient of friction are used, but metal pipes such as stainless steel pipes can also be used. In the figure, the slider is integrally molded as a whole, but the guide pipe 8 may be made separately and combined. The tip of the pipe 8 is preferably formed into a tapered surface 9, and a flange 10 is formed in the middle, and the slider 5 can move forward until the flange 10 abuts against the step 11 of the base 2. The base is also preferably made of a synthetic resin material such as polyacetal resin or polyamide resin, which has the same effect as the guide pipe.

At the rear of the slider 5, there is a chuck 13 which is made by combining two chuck elements 12, 12 in a complementary cylindrical shape so as to be able to grip the core, and a chuck 13 which is fitted onto the outer periphery of the chuck and which is attached to the outer surface of the chuck element 12. A chuck ring 17 having a tapered surface 16 formed on its inner surface is provided so as to receive and support a ball 15 seated in the formed recess 14, and the chuck ring 17 is fitted into the connecting cylinder 3. The facing surface of the chuck element 12 is formed with a rough surface such as an uneven surface as appropriate to hold the core holding portion 1.
8, and a tapered surface 19 is formed at the front and rear to guide the core, so that the front and rear are similar in shape. A spring 20 is provided between the flange 10 of the slider 5 and the chuck 13 to cause the tip of the guide pipe 8 of the slider 5 to protrude from the tip of the base 2 and to bias the chuck 13 rearward. .

The connecting tube 3 at the rear of the chuck 13 has a core 4.
A core guide 21 having an inverted conical tapered surface is fitted to guide the core to the chuck.

A core cap 22 having a diameter slightly smaller than the inner diameter of the barrel 1 is attached to the rear end of the core 4 so as to be able to come into contact with the inner surface of the barrel. The core cap 22 is made of an appropriate material such as polypropylene or other impact-resistant synthetic resin material, styrofoam, foamed urethane or other synthetic resin foam, natural rubber, synthetic rubber, metal material, or other suitable material to reduce impact. The one shown in FIG. 1 has a conical shape with an insertion hole 23 formed in the center, and a small protrusion 24 provided in the hole, which is tightly fitted into the rear part of the core 4. The insertion hole 23 may be a through hole having a smaller diameter than the outer diameter of the core, as shown in FIG. Incidentally, the shaft cylinder 1 can also be made transparent from a transparent or semi-transparent material. In this case, if it is made into an appropriate design shape 25 such as a character shape as shown in FIG. It can be assumed that there is. A tail plug 26 is provided at the rear end of the shaft cylinder 1. As shown in the figure, the outer periphery of the core cap 22 is close to the inner surface of the shaft cylinder 1, but if the connecting cylinder 3 is provided with a core tank (not shown) extending into the shaft cylinder as is known in the art. In this case, the outer periphery of the core cap 22 may be formed close to the inner surface of the core tank.

In use, the core 4 is pushed from behind the chuck 13 through the core guide 21 with the barrel 1 removed, and is advanced until it coincides with the tip of the slider 5. At that time, check 13
is pushed forward on the way, but then returns to the rear (the position shown in the figure) by the action of the spring 20, grips the lead, and can withstand the pressure of the writing. Then, by connecting the shaft tube 1 to the base 2, writing can be performed as usual. When the lead 4 decreases due to use, the slider 5 is also pushed back, but when the writing tip is removed from the paper surface, the slider 5 moves forward by the action of the spring 20, and the lead 4 moves forward accordingly. In this case, the chuck means permits advancement of the core in a known manner.

Since the present invention is constructed as described above, the core cap is attached to the inner surface of the barrel so that the core can come into contact with the inner surface of the barrel even if it is handled roughly during use or falls on the floor. Since they are in contact, there is no risk of bending, and if the shaft is made transparent as shown above, the amount of remaining core can be easily seen by looking through the core cap, making it very interesting from a design standpoint. can be taken as a thing.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a partially omitted cross-sectional view, and FIGS. 2 and 3 are a cross-sectional view and a front view, respectively, of a modified example of the core cap. 1... shaft cylinder, 4... core, 22... core cap.

Claims (1)

[Claims for Utility Model Registration] 1. In a sharp pencil having a lead chuck means inside the barrel, a lead cap having a diameter slightly smaller than the inner diameter of the barrel is attached to the rear of the lead so as to be able to come into contact with the inner surface of the barrel. A sharpening pencil. 2. The sharp pencil according to claim 1, wherein the chuck means has an automatic feeding mechanism configured to automatically feed out the lead as the pencil is written. 3. The sharp pencil according to claim 1 or 2, wherein the barrel is transparent.