JPH0440952Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is based on the fact that when the core guide pipe, which is biased forward in the axial direction, is located at the most forward position, the chuck is slightly advanced and expanded, and the next core is opened. This invention relates to a chuck expanding device for an automatic mechanical pencil that automatically follows the movement of the chuck.

[Conventional technology]

Conventionally, in the case of a sharp pencil in which the next lead automatically follows, the chuck is built into the barrel by being biased backward in the axial direction by a chuck spring with a weak elastic force, and the lead guide pipe is moved forward in the axial direction. When it was in position, it pushed the rear end of the chuck and moved forward slightly, expanding due to the chuck's own elasticity.

[Problem that the invention attempts to solve]

Therefore, in an automatic mechanical pencil with a weak chuck spring, there is a risk that the chuck will not close completely and the lead will move back during writing. Moreover, if the chuck is installed even slightly off-center, a problem arises in that the next core cannot fall into the chuck.

[Means for solving problems]

The structure of the present invention that improves the above-mentioned problems will be explained using FIG. and the sliding tool 10
The connecting rod portion 10A is a fastener 4 provided on the shaft tube 12.
Insert the inner flange 10B into the chuck 7 by inserting it through the through hole 4C.
It is located behind the rear end of the. A pipe 11 is fixed to the inner collar 10B of the sliding tool 10, and the pipe 1
The tip of chuck 1 is inserted into the rear cylindrical portion of chuck 7, which is biased axially rearward by chuck spring 8, and abuts against inner stage 7c.

[Effect]

In the state shown in FIG. 1, when the pipe 11 comes into contact with the inner stage 7c of the chuck 7, the front part of the chuck 7, which is divided into several pieces, is spread apart, and the shaft cylinder 12 of the chuck 7 is moved in the outer circumferential direction. By slightly correcting the deviation, the core holding portion 7D of the chuck 7 and the hole of the pipe 11 are aligned. Therefore, when the lead 1 in use becomes short, the next lead 1 is smoothly dropped into the chuck 7. Then, when writing and pressing the tip of the lead 1 and lead guide pipe 5 against the paper surface,
The core guide pipe 5 moves back slightly against the elastic force of the front spring 6, and the sliding tool 10 and pipe 11 that interlock with the core guide pipe 5 also move back, and the pipe 11 is separated from the inner stage 7c of the chuck 7. do. Then, the chuck 7 is moved backward by the chuck spring 8, and the ball 9 rotatably provided on the head 7B of the chuck 7 is brought into contact with the tapered surface 4D that narrows as it goes rearward in the axial direction of the fastener 4. They are brought into contact and closed, and the core 1 is strongly held, resulting in the state shown in FIG.

〔Example〕

Examples of the present invention will be described below.

In FIG. 1, a lead holder 2 that holds the lead 1 with an appropriate force is built into the base 3 so as to be freely slidable in the axial direction, and the front stage 4A of the fastener 4 and the lead guide pipe 5 are screwed onto the base 3. Between the outer flange 5A and the front spring 6
By stretching the core guide pipe 5, the outer flange 5A of the core guide pipe 5 comes into contact with the locking step 3A of the cap 3. A chuck 7 is built into the fastener 4 so as to be able to swing in the axial direction and the radial direction (the outer peripheral direction of the barrel), and between the rear outer stage 7A of the chuck 7 and the inner stage 4B of the fastener 4 , a chuck spring 8 having a step force weaker than the front spring 6 is stretched to urge the chuck 7 rearward in the axial direction, and a ball 9 is rotatably provided on the head 7B of the chuck 7. In FIG. 1, only the front part of the chuck is divided into several pieces, but there will be no problem if the chuck is completely divided into each piece. The connecting rod portion 10A of the sliding tool 10 fixed to the core guide pipe 5 is inserted through the through hole 4C of the fastener 4,
The inner flange 10B of the sliding tool 10 is located axially rearward from the rear end of the chuck 7. A pipe 11 is fixed to the inner collar 10B of the sliding tool 10.
The tip of the chuck 7 is inserted into the rear cylindrical portion of the chuck 7 and comes into contact with the tapered inner stage 7C, thereby expanding the chuck 7 appropriately. Although not shown, it may be loosely fitted between the inner stage of the pipe chuck and the inner collar of the sliding tool. A shaft tube 12 is screwed to the rear of the fastener 4, and a spare core 1 is installed behind the funnel-shaped portion 12A of the shaft tube 12.
(Although not shown, the fastener and the shaft tube may be integrally constructed).

In the state shown in FIG. 1, by bringing the pipe 11 into contact with the inner stage 7C of the chuck 7, the chuck 7 is appropriately pushed out and the chuck 7 is expanded.
The core holding portion 7D of the chuck 7 and the hole of the pipe 11 are aligned by slightly correcting the deviation in the radial direction.
Therefore, when the lead 1 in use becomes short, the next lead 1 can automatically and smoothly fall into the chuck 7. When writing next time, by pressing the lead 1 and the lead guide pipe 5 against the paper surface, the lead guide pipe 5 is slightly retracted against the elastic force of the front spring 6. As a result, the sliding tool 10 and the pipe 1 are linked to the core guide pipe 5.
1 also moves backward, and pipe 1 is inserted from the inner stage 7C of chuck 7.
1 is separated. Then, the chuck 7, which is urged backward by the chuck spring 8, comes into contact with the tapered surface 4D of the fastener 4, where the ball 9 provided on the head 7B becomes narrower as it goes rearward in the axial direction. When closed, the ball 9 and the fastener 4 are attached to the rear in the axial direction.
The core 1 is held with strong force by the wedge action of the tapered surface 4D, resulting in the state shown in FIG. When writing is performed in this state, the lead guide pipe 5 retreats as the lead 1 wears out, and writing is performed. When writing is stopped, the lead guide pipe 5 is moved forward by the front spring 6 and returns to the state shown in FIG. 1.

In the embodiment described above, the core guide pipe always moves forward in the axial direction when it is separated from the plane of the paper, but in the embodiment shown in FIG. A plurality of balls 1 are rotatably provided on the retainer 13, and a tapered surface 112C is provided that widens as it approaches.
4 to the shaft cylinder 112 by the elastic force of the rear spring 15.
A core guide pipe 5 is brought into contact with the tapered surface 112C of the retainer 13, and the outer flange 13A of the retainer 13 is brought into frictional contact with an elastic body 16 such as rubber fixed to the inner surface of the shaft tube 112C with a stronger elastic force than the rear spring 15.
The chuck expanding device of the present invention is provided in an automatic dispensing type sharp pencil which constitutes an intermittent moving device and is provided with an intermittent moving device for the lead guide pipe 5. In this embodiment, the core guide pipe 5 retreats as the core 1 wears, but even if the tip of the core guide pipe 5 is moved away from the plane of the paper, the wedge between the ball 14 and the tapered surface 112C of the shaft cylinder 112 remains as shown in FIG. Since the outer surface 110C of the sliding tool 110 is held by the action, the core guide pipe 5 does not move forward. Then, when writing continues and the lead 1 wears out a certain amount, the rear outer stage 110D of the sliding tool 110 moves to the retainer 13.
The retainer 13 is moved backward, and the wedge action between the tapered surface 112C of the shaft cylinder 112 and the balls 14 is released. Moreover, at this time, the outer flange 13A of the retainer 13 is in frictional contact with a force stronger than the rear spring 15, so the retainer 13 does not move forward. Therefore, the core guide pipe 5 moves forward due to the elastic force of the front spring 6, and the tip of the pipe 11 contacts the inner stage 7C of the chuck 7 to expand the chuck 7, and the outer flange of the rear end of the sliding tool 110 110E
is in contact with the rear end of the retainer 13 and the retainer 1
3, the ball 14 comes into contact with the tapered surface 112C of the shaft cylinder 112, and returns to the state shown in FIG.

[Effect of idea]

As explained above, in the present invention, when the core guide pipe that is biased forward in the axial direction is located at the most forward position in the axial direction, the tip of the pipe that interlocks with the core guide pipe comes into contact with the inner stage of the chuck. The feature is that the chuck is pushed out and the radial offset of the chuck is slightly corrected to align the center of the chuck's core holding part and the pipe hole.

This eliminates the need for the chuck itself to have spring properties for expansion, so the chuck can be reliably closed with a small amount of force and the core can be strongly held. Furthermore, since the chuck is pushed open by the pipe, the chuck can be opened reliably and the next core can be reliably dropped into the chuck.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the main part of the embodiment of this invention showing the chuck in an expanded state, Fig. 2 is a longitudinal sectional view of the main part showing the writing state of the embodiment of Fig. 1, and Fig. 3 is a longitudinal sectional view of the main part of the embodiment of this invention. FIG. 4 is a longitudinal cross-sectional view of the main part showing the chuck in an expanded state in another embodiment of the invention, and FIG. 4 is a longitudinal cross-sectional view of the main part showing the writing state of the embodiment of FIG. 1... core, 5... core guide pipe, 7... chuck, 7C... inner stage of chuck 7, 7D... core holding part of chuck 7, 8... chuck spring,
11...Pipe.

Claims (1)

[Scope of utility model registration request] As the core wears, the core guide pipe retreats, and by moving the core guide pipe forward, the core is fed out. When the core guide pipe is positioned at the most forward position in the axial direction, the chuck expands, and the cores are gradually inserted into the chuck. A self-feeding sharp pencil that automatically follows a lead guide pipe, a chuck whose front part including at least a lead holding part is divided into two or more pieces, and a chuck that is moved rearward in the axial direction. Consisting of a chuck spring that biases, when the core guide pipe is positioned at the frontmost position in the axial direction, the front part of the pipe inserted into the rear cylinder of the chuck comes into contact with the inner stage of the chuck, causing the chuck to expand appropriately. A chuck expanding device for an automatic mechanical pencil.