JPS5852958Y2 - Shape pencil - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mechanical pencil, and more particularly to a mechanical pencil with an improved base assembly structure.

Conventional mechanical pencils generally have a cap connected to the tip of the barrel, and a lead protrudes from the tip of the cap.

However, mechanical pencils with the above structure conventionally incorporate components such as a chuck from the base connection end of the barrel, a coil spring for chuck ring knocking, etc., and then screw the base into the barrel to hold down these parts. Because of this, when screwing the cap onto the tip of the shaft cylinder, you have to hold the cap with your fingers to prevent the coil springs from popping out, which makes assembly difficult and time-consuming. This resulted in poor performance and a significant decrease in assembly efficiency.

In particular, when adding a means to prevent the lead from retracting and breaking when excessive writing pressure is applied to the lead, a coil spring to provide that cushion is incorporated in addition to the knock spring. , it becomes even more difficult to assemble.

Furthermore, since the cap and the barrel must be individually machined, there is a drawback that the parts are expensive.

The present invention was developed with the aim of eliminating the above-mentioned problems of the conventional method, and involves forming an engaging stepped portion at the inner end of the base fitting hole formed at the tip of the shaft cylinder. A cylindrical shaft-tube fitting part that can be press-fitted into the cap fitting hole is formed at the rear of the cap, and a plurality of slits are cut in the axial direction from the rear end of the shaft-tube fitting part. At the same time, an engagement protrusion that can be engaged with the engagement step is formed on the outer edge of the rear end, and the shaft tube fitting portion is press-fitted into the base fitting hole, and the engagement protrusion is attached to the engagement step. The present invention provides a mechanical pencil characterized in that the mouthpiece is connected to the barrel by engagement.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an enlarged cross section of a mechanical pencil according to an applied example of the present invention, in which an engaging stepped portion (retaining portion) 3 is formed at the inner end of the base fitting hole 2 at the tip of the barrel 1. .

The cap 4 is made of plastic, has a core insertion hole 5 penetrating its axis, and has a cylindrical shaft fitting portion 6 formed at the rear of the cap 4 .

A plurality of slits 7 are cut from the rear end of this shaft cylinder fitting portion 6, and the engagement protrusion 8 is provided protruding from the outer edge of the rear end.

This engagement protrusion 8 is such that when the shaft cylinder fitting part 6 is fitted into the base fitting hole 2 of the shaft cylinder 1, the stepped surface 9 of the base of the shaft cylinder fitting part 6 is at the tip of the shaft cylinder 1. It is formed so as to engage with the retaining step portion 3 when it comes into contact with the retaining step portion 3.

In addition, the chuck 10 incorporated into the shaft cylinder 1, the knock spring 11 for restoring this chuck 10. The components such as the chuck ring 12 that opens and closes the chuck 10, the cushion spring 13 that retracts the core and prevents the core from breaking when excessive pressure is applied to the core, and the sleeve 14 that pressurizes the core are made of a shaft cylinder. It can be installed by dropping the rear end side of 1.

Therefore, when connecting the shaft tube 1 and the base 4, if the shaft tube fitting part 6 of the base 4 is press-fitted into the base fitting hole 2 at the tip of the shaft tube 1 into which the component parts have been assembled in advance, The barrel fitting part 6 is inserted into the cap fitting hole 2 by deflection in the axial direction, and at the same time as the tip of the barrel 1 contacts the step surface 9, the engaging protrusion 8 is removed from the cap fitting hole 2. It comes out and is engaged with the retaining step part 3 by the elastic restoring force, and is connected again without coming off.

Thereby, the cap 4 can be fixed to the shaft cylinder 1 with a single touch.

FIG. 3 shows another embodiment of a mechanical pencil according to an applied example of the present invention, in which a radial hole (retaining portion) 15.15 is bored at the inner end of the base fitting hole 2 of the barrel 1. And this hole 15
．． 15 so that the engaging protrusion 8 of the cap 4 is engaged therewith.

According to this embodiment, the cap 4 can be opened by inserting the engaging protrusion 8 inward from the outside of the hole 15.15 if necessary.
can be used to remove it from the shaft tube 1.

For this purpose, a hole 15.15 can also be drilled in the retaining step 3 in the embodiment shown in FIG.

FIG. 4 shows an embodiment of the present invention, which includes a shaft cylinder fitting part 6 of a base 4 and extends in the axial direction, and inside this shaft cylinder fitting part 6 there is a chuck 10, which is the above-mentioned component. Knock spring 11.
Chuck ring 12, cushion spring 13, sleeve 1
4, a C-ring-shaped retaining ring 17 is fitted into the protrusion 16 formed on the inner edge of the rear end of the shaft tube fitting part 6 to prevent the cushion spring 13 from being removed and to attach the chuck 10 to the chuck 10. It is designed to serve as a guide for the core tube 18 to be coupled.

In this embodiment as well, the components can be assembled into the base 4 in advance and then simply inserted into the base fitting hole 2 of the shaft tube 1 to connect them.

As described above, according to the mechanical pencil according to the present invention,
Since the connection can be made by simply inserting the cap into the tip of the barrel, installation is extremely simple, and at the same time, as shown in the illustrated embodiment, the component parts are assembled into the barrel or the cap, and the cap is assembled. Since it is possible to create a structure that only requires fitting, it is possible to eliminate the work of holding down other components from protruding when connecting the cap, and it is possible to significantly improve the work efficiency of assembly work. .

In the illustrated embodiment, the base is made of plastic, but it may also be made of metal such as a light alloy.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway enlarged sectional view showing an embodiment of a mechanical pencil according to an applied example of the present invention, Fig. 2 is a side view of the base, and Fig. 3 is a schematic diagram showing an embodiment of an applied example of the present invention. Fig. 4 is an enlarged sectional view of a main part showing an embodiment of the present invention. 1... shaft cylinder, 2... base fitting hole, 3...
...Engagement stepped portion, 4...Base, 5...
... Core insertion hole, 6 ... Shaft tube fitting part, 7 ...
...Slit, 8...Engaging protrusion, 9...
・Step surface, 10...Chuck, 11...
Knock spring, 12...Chuck ring, 13.
... Cushion spring, 14 ... Sleeve, 15 ... Hole, 16 ... Flange, 17.
...Retaining ring.

Claims (1)

[Scope of utility model registration request] The shaft cylinder 1 for gripping has retaining parts 3, 15 such as steps and holes near the tip, and the engaging protrusion 8 protrudes outward from the outer edge of the rear end. A cap 4 that is press-fitted into the engaging portion 3.15 of the cap, a slit 7 cut in the axial direction from the rear end of the cap 4, and a core tube 1 installed in the cap 4.
8. A mechanical pencil equipped with a lead feeding mechanism such as a chuck 10, a sleeve 14, and a spring 11.