JPH0335588Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field) The present invention involves an operation in which the tip of a sharp pencil mechanism (hereinafter referred to as a cursive) housed in a barrel is made to protrude from the tip of the cursive This invention relates to a sharp pencil with a built-in writing body, in which the operation of drawing out the lead when it is in use, protruding from the tip of the barrel, can be performed by pressing the same notch.

(Prior art) The operation of causing the tip of the writing body stored in the barrel to protrude from the tip of the barrel, and the operation of drawing out the lead when the writing body is in use and protrudes from the tip of the barrel, are performed using the same technique. As a sharpening pencil with a built-in cursive character that can be written by pressing, Jikosho
As disclosed in Publications No. 51-34328 and No. 51-34329, a first spring urges the writing body backward and the writing body stored in the barrel is moved by a well-known forward and backward mechanism (Tokuko Showa).
(Refer to Publication No. 34-7181), it can be stopped at two positions, front and back, and the elastic force of the second spring that biases the lead tank located inside the writing body and connected to the chuck rearward is transferred to the first spring. A structure is known in which the core tank is set to be weaker and a notch is arranged at the rear of the core tank so as to protrude from the rear end of the barrel.

However, in the structure described above, the elastic force of the second spring that biases the chuck backward is weaker than that of the first spring that biases the writing body backward.
When the chuck is pressed to put it in the used state or the unused state, the second spring, which urges the chuck backward, contracts before the first spring, so the chuck moves forward a certain distance while holding the core. Then, the lead is fed out once. Therefore, even when not in use, the core may be exposed from the tip of the barrel, or when in use, the core may protrude more than necessary and the centering length must be adjusted by adding a new notch. There is a problem that it does not.

To solve this problem, as disclosed in Japanese Patent Publication No. 50-25846, by adding a structure to the above-mentioned structure to restrict the backward movement of the lead tank when storing the writing, There is a known structure in which the chuck is opened to prevent the lead from coming out when the chuck is in use, but even with this structure, since the chuck is left open when not in use, it cannot be easily accessed from the outside. Although it has the additional effect of preventing lead breakage due to chuck biting when an impact is applied, the lead is still extended as before when not in use.
Although the frequency with which the lead is drawn out can be reduced by half, the fundamental problem has not been solved.

(Purpose) This invention was created in view of the problems mentioned above.
The primary purpose of a mechanical pencil with a built-in cursive body is to prevent the lead from coming out when the cursive body appears and disappears, and also to prevent the lead from being drawn out when the cursive body is removed, and when not in use, the chuck will not exceed the necessary level in the event of an unexpected impact from the outside. The second purpose is to prevent the core from breaking due to biting into the core.

(Example) Fig. 1 shows a sharp pencil in an unused state, and reference numeral 1 is a barrel made of metal, resin, etc., and a writing body 8, which will be described later, is located at the rear of the barrel 1 in the longitudinal direction. A slit 2 is formed which is longer than the forward and backward distance. Reference numeral 3 denotes a clip that is arranged to fix its base 4 to the barrel 1, and in the illustrated example, the base 4 of the clip 3 is annular, and the annular part has a rear metal plate that can be screwed onto the rear part of the barrel 1. 5 shows a method of clamping, but other known fixing methods may be used. The clip 3 has a clamping protrusion 6 formed at the front thereof located at the front end of the slit 2, and the protrusion 6 has a recess into which an engaging part 16 of a cylinder 9, which will be described later, can engage. It has 7 locations. 8 is the shaft cylinder 1
The writing body 8 is a writing body which is biased backward by a first spring S ₁ which is weaker than the repulsive force of a second spring S ₂ which will be described later. Core pipe 10 and core detent 11 screwed onto the front part
This is a well-known knock-type sharp pencil consisting of a tip body 12 having a cylindrical body 9, a chuck 15 which is connected to a lead tank 14 which has a chuck ring 13 fitted inside the cylinder body 9 and is biased backward by a second spring _S2 . It is a mechanism. Reference numeral 16 denotes an engaging portion formed at the rear of the cylinder 9, and the engaging portion 16 is slidably disposed within the slit 2 with a portion thereof protruding from the outer surface of the shaft cylinder 1. Reference numeral 17 indicates a locking portion formed by fixing a ring to the rear portion of the core tank 14, but the locking portion 17 may also be formed by forming a collar integrally with the core tank 14. In the present invention, the elastic force of the first spring _S1 , which urges the writing body 8 backward, is set to be weaker than that of the second spring, which urges the chuck 15 and the lead tank 14 backward, as shown in FIG. When not in use, the engaging portion 16 is connected to the slit 2.
The engaging portion 17 is located in contact with the front end of the rear metal 5. 18 is the shaft cylinder 1
It is a notch that protrudes from the rear end and is fitted into the rear part of the lead tank 14, and 19 is an eraser.

Next, the action will be explained.

If the knob 18 is pressed in the state shown in FIG. 1, that is, in the unused state, the elastic force of the first spring _S1 is weaker than that of the second spring _S2 , so the chuck 15 is biased backward by the second spring _S2 . The entire writing body 8 moves forward while maintaining the state in which the lead L is held in between. With this forward movement, the engaging portion 16 also moves forward within the slit 2 and eventually engages with the recess 7 of the clip 3, so if the pressure on the notch 18 is released here, the writing 8 will appear as shown in FIG. The distal end portion can be used in a state where it protrudes from the distal end of the shaft cylinder 1.

In the usage state shown in FIG. 2, the forward movement of the writing body 8 is restricted by the intermediate step 12a of the tip 12, the inner step 1a of the barrel 1, or the front end of the engaging portion 16 by the front end of the recess 7. Therefore, if the chuck 18 is pressed in this state, the chuck 15 will move forward with respect to the cylinder 9, and the lead L can be fed out.

To change the used state from the used state shown in FIG. 2 to the unused state, lift the clamping protrusion 6 of the clip 3 upward, or push down the rearwardly extending portion 3a of the clip 3 to connect the engaging part 16 and the recess. 7, and the entire writing body 8 retreats due to the repulsive force of the first spring _S1 . Even during this transition, the chuck 15 is urged backward by the second spring _S2 and maintains the state in which it grips the core L.

(Effects) As is clear from the above explanation, in the present invention, the elastic force of the first spring S ₁ that urges the writing 8 backward is set to be weaker than that of the second spring S ₂ .
When the tip of the writing body 8 is projected from the tip of the barrel 1 to be in use, and when the tip of the writing body 8 is stored in the barrel 1 and is not in use, the chuck 15 is Since the second spring _S2 is always biased backward and the state in which the lead L is held is maintained, the lead will not be drawn out unnecessarily.

Further, when not in use, the chuck 15 is prevented from moving backward by a locking part 17 provided on the core tank 14, and the engaging part 16 is located between the rear end of the slit 2 and the bottom. In short, the cylinder 9 is the first
Since it is held between the spring S ₁ and the second spring S ₂ and is in a balanced state, even if an unexpected shock is applied from the outside in this state, no force will be applied to the chuck 15 to close it compared to the normal state, and the chuck will close. This prevents breakage of the lead due to the chuck 15 biting into the lead L more than necessary, and further urges the chuck 15 backward when not in use, in other words, urges the cylinder body 9 forward. Since the elastic force of the second spring _S2 is relieved by the first spring _S1 acting in the opposite direction, the chuck 15 will not gradually dig into the core L even if it is not used for a long time. This also prevents damage to the surface of the lead L.

In the embodiments shown in FIGS. 1 and 2, the engaging portion 16 provided on the cylinder body 8 as a mechanism for advancing and retracting the writing body 8 is shown as being engaged with the recess 7 of the clip 3. However, as shown in FIG. 3, the mechanism for advancing and retracting the writing body 8 has an engaging portion 16 in a hole 1b provided in the shaft tube 1.
It is also possible to adopt a method in which the engaging part of the writing body is engaged with the barrel or the clip, and the engagement is released directly with a part of the clip 3 or with a finger. Various methods can be used as long as they are possible.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a vertical sectional view showing the non-use state, FIG. 2 is a vertical sectional view showing the used state, and FIG. 3 is a main part showing another forward/backward mechanism. FIG. 1... shaft cylinder, 3... clip, 5a... step part,
8... Cursive writing, 16... Engaging portion, 17... Locking portion, S ₁ ... First spring, S ₂ ... Second spring.

Claims (1)

[Scope of utility model registration request] In a sharp pencil with a built-in cursive body, in which the engaging part of the cursive body is brought into use by engaging with the barrel or the clip, and the writing body is brought into the unused state by releasing the engagement, the engaging part is not used. When the first spring is loosely inserted in the slit of the barrel and biases the writing body backward, the elastic force of the first spring is made weaker than that of the second spring located inside the writing body and biasing the chuck backward; A sharp pencil with a built-in writing body, characterized in that the lead tank of the writing body is provided with a locking part that comes into contact with the inner stage of the barrel cylinder and restricts its backward movement.