JPH0346942Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> This invention eliminates the need for special knob operations when the lead wears out during writing by releasing the writing pressure while maintaining the writing posture. This invention relates to a sharp pencil that can be used for continuous writing and can be used in the drawing head of an automatic drafting machine.

<Prior art> To eliminate the need for a special knob operation, to convert the writing pressure itself into an operation for centering, and to feed out the lead extremely reliably by simply applying and releasing the pressing force for writing during writing. As a sharpening pencil that can
(filed on the 27th) (Japanese Patent Application Laid-Open No. 60-229797). This includes two sliders, a wedge means for keeping the second slider in the retracted position, which increases the amount of retraction each time writing pressure is applied to the lead, and a wedge means for keeping the first slider, which has been retracted by the writing pressure, in the retracted position. The structure has two sliders, which is called a double slider structure, and is provided with another wedge means for holding the slider in place.

<Problems to be solved by the invention> In the case of the above structure, if the core protruding from the core guide tube is broken and the tip of the core and the tip of the core guide tube are on the same plane, the tip of the core is pressed against the paper surface and There is still room for improvement in that it is not possible to accumulate the amount of retraction of the second slider when the two sliders are retracted step by step and locked at each position.

<Means for Solving the Problems> The present invention includes a chuck mechanism comprising a chuck body and a chuck actuating body that hold the lead and prevent the lead from retreating after a certain amount of retreat, and the chuck mechanism At the front, there is a lead having wedge means for locking a first slider that moves back in response to writing pressure and a second slider that has a lead-carrying member therein and that moves back by increasing amounts each time writing pressure is applied to the respective retreated positions. In the sharpening pencil capable of automatically dispensing a fixed length, a third slider is provided in front of the second slider and has a lead guide tube and is elastically biased rearward so as to come into contact with the front end of the second slider. When writing in a state where the lead does not protrude from the lead guide tube, the second slider is moved back by the retreat of the third slider due to writing pressure, so that the lead comes into contact with the paper surface, and the lead is moved back together with the chuck body that clamps the lead. When the writing pressure is released, the second slider is locked in the retracted position by the wedge means, and the chuck body holding the lead moves forward to project the lead.

<Embodiments> Hereinafter, preferred embodiments of the present invention shown in the drawings will be described in detail.

In FIG. 1, reference numeral 1 denotes a barrel that constitutes the pencil body, and it has many members and parts such as a front barrel 1a, a middle barrel 1b, and a rear barrel 1c, but its structure itself is Since this is clear from the illustrations and is not the gist of the present invention, a detailed explanation will be omitted.

Inside the shaft tube 1, a mantle tube 2 is installed inside the central shaft portion 1b, and a core tank portion 4 that frictionally engages with the mantle tube 2 via a pusher 3 is provided. Therefore, it is biased backwards. Inside the mantle tube 2, a chuck actuating body 6 having an inclined surface 6a is urged forward by a spring 7, and inside thereof a chuck body 9 having a trochanter 8 is urged rearward by a spring 10. It is placed in a energized state. In addition, code 11
This is a rubber ring that is fitted onto the rear ends of two opposing chuck pieces to apply a self-opening force to the chuck pieces to form a chuck body, but the structure of the chuck body is limited to this example. Of course not.

The above structure is largely the same as that of the conventional sharpening pencil or that described in the specification of Japanese Patent Application No. 85606/1983.

The sharpening pencil of the present invention differs from conventional ones in the following points.

A first slider 16 is disposed in the front shaft portion 1a having an inclined surface 13, which holds a trochanter 14 in a small diameter portion at the front and another trochanter 15 at a large diameter portion at the rear. Approximately inwardly of this first slider 16 is a spring 1 whose rear end is supported by a stop 18 fixed to the front shaft portion 1a.
The second slider 20 is biased forward by 9.
is arranged to be movable in the axial direction. The second slider 20 has a protrusion 2 that comes into contact with the first slider.
1 on the outer surface, and a core entraining member 22, such as a rubber ring, is fixed to the inner surface. Furthermore, the second slider 20 is connected to the stopper 1.
It has a shoulder portion 23 that engages with 8 to prevent it from retreating beyond a certain level. A third slider 26 is disposed in front of the second slider 20 and is provided with a core guide tube 24 that is normally in contact with the front end of the second slider 20, and is biased rearward by a spring 25 and is movable in the axial direction. ing. Between the rear trochanter 15 of the first slider 16 and the second slider 20,
A sliding cylinder 30 is provided which is urged backward by a spring 28 with respect to the first slider 16 and has an inclined surface on its outer surface so that it can come into contact with the rear trochanter 15 .

Next, the operation of the sharpening pencil according to the present invention will be explained with reference to FIGS. 1 to 8 and 9 to 11.
The centering operation is shown when the core is protruding from the core guide tube 24, and FIGS. 9 to 11 show the centering operation when the core is not protruding from the core guide tube 24.

When writing is performed with the lead protruding as shown in FIG. 1 and the tip of the lead is pressed against the paper surface, the lead moves back while being held by the chuck body 9 by the retractable amount L1 of the chuck operating body 6. Simultaneously with this retraction of the lead, the second slider 20, which is provided with a lead-carrying member 22 that elastically holds the lead, is also moved back by the same amount, accompanied by the retracting lead. Further, the third slider 26 also moves back by the same amount while maintaining the contact state with the second slider (see FIG. 2).

In the writing state shown in FIG. 2, when the pen pressure is released and the tip of the lead is pulled away from the paper surface, the chuck actuating body 6 moves forward and returns due to the elastic force of the spring 7, so that the same amount of lead is held between the chuck body 9. Advance. As the core moves forward, the second slider 20 also tries to move forward, but
At this time, since a wedge action occurs between the front trochanter 14, the inclined surface 13 of the shaft cylinder 1, and the second slider 20, the second slider 20 does not move forward but remains at the retreated position. Furthermore, since the third slider 26 also remains under the action of the spring 25,
It stays in the backward position without moving forward. That is, the third
As shown in the figure, when writing is canceled, the lead and chuck body 9 move forward, but the second slider 20 and the third
Since the slider 26 remains at the retracted position in FIG. 2, the distance L1 is added to the amount of writing consumption subtracted from the amount of lead protrusion in FIG.
This means that the core protrudes from the tip of the core guide tube (see Figure 3).

FIG. 4 shows a state in which the second slider 20 has retreated to the rearmost position after repeating the above operation several times, and its shoulder abuts against the front end of the stopper 18. In this state, the third slider 26 is prevented from retreating at the position where it contacts the first slider 16.

When you start writing again from the state shown in Figure 4, the second
Since the slider 20 has already retreated to the rearmost position, it cannot retreat any further, so even if the tip of the core is pressed against or released from the paper surface, the core will not protrude further from the core guide tube 24. , the lead is only worn out by writing (see Figure 5).

FIG. 6 shows a state in which writing is performed from the state shown in FIG. 5, and the lead is worn out so that the lead and the lead guide tube 24 are flush with each other or the lead guide tube 24 is in contact with the paper surface. As you write, the third slider 26 moves to the first slider 1 by pressing the lead guide tube 24.
6 moves rearward, the front trochanter 14 is separated from the inclined surface 13 and the second slider 20, and the wedge action by the trochanter 14 is released.

If the tip of the core is moved away from the plane of the paper, the first slider 16 will stop at its retreated position due to the wedge action of the rear trochanter 15, so the second slider 20
moves forward and contacts the third slider 26. In this forward movement process of the second slider 20, the second slider 20 first moves forward through the gap between the second slider 20 and the third slider 26, and then, after coming into contact with the third slider 26, the third slider 26 is carried away. This movement difference becomes the centering length l that protrudes from the core guide tube (FIG. 7).

In the state shown in FIG. 7, the first slider 16 is still in the retracted position, so the three sliders 16, 20, 26 move further forward from the state shown in FIG. 7 until a wedge action occurs on the anterior trochanter 14. (See Figure 8).

The above explanation relates to feeding out the lead from a state in which the lead has already protruded from the lead guide tube 24, but next, referring to FIGS. A brief explanation of centering in this case will be given below.

As shown in FIG. 9, when an attempt is made to start writing by pressing the tip of the lead guide tube 24 against the paper surface with the lead not protruding from the lead guide tube 24, the second slider 20 is pushed backward by the third slider 26. At the same time, since the core comes into contact with the paper surface P in this process, the chuck body 9 that holds the core also retreats by the retractable amount of the chuck actuating body 6 (10th
(see figure).

When the tip of the core guiding tube 24 is moved away from the plane of the drawing from the state shown in FIG. 10, the chuck actuating body 6 moves forward and returns due to the elastic force of the spring 7, so that the core held by the chuck body 9 also moves forward by the same amount. As the core advances, a forward force is also applied to the second slider 20, but in this direction, a wedge force is generated by the front trochanter 14, so the second slider 20 does not move forward and remains at its retreated position. The core protrudes from the tip of the core guide tube by approximately the difference between the two. The subsequent operations are the same as those shown in FIGS. 1 to 8, so the explanation will be omitted.

<Effects of the invention> Since the sharpening pencil of the present invention is constructed as described above, even if the lead guide tube 24 and the lead become flush (for example, due to the lead breaking),
While the first slider 16 remains in the same position, the third slider 26 and the second slider 20 can be moved back by pressing the tip of the lead guide tube 24 against the paper surface when writing, and are locked in the retreated position. When pressed for the first time from the flush state, the lead protrudes from the tip of the lead guide tube 24 by an amount equivalent to the amount of retraction of the chuck body, and thereafter writing can be performed by pressing the lead against the paper surface.

[Brief explanation of the drawing]

1 to 11 are partially cutaway sectional views of a sharpening pencil showing the structure and operating state according to a preferred embodiment of the present invention, and FIGS. 1 to 8 show the lead in a state where the lead has already protruded. Figures 9 to 11 are diagrams showing the operation of drawing out the lead after starting writing with the lead not protruding from the tip of the lead guide tube of the pencil body. 6...Chuck operating body, 9...Chuck body, 1
6...first slider, 20...second slider, 22...core entrainment member, 24...core guide tube, 2
5... Spring, 26... Third slider.

Claims (1)

[Scope of utility model registration request] A chuck mechanism is provided which includes a chuck body 9 and a chuck actuating body 6 that hold the lead and prevent the lead from retreating after a certain amount of retraction, and in front of the chuck mechanism is a first slider that retreats due to writing pressure. 1
6, and a sharp pencil capable of automatically feeding out a lead to a fixed length, which has a lead entraining member 22 inside and has a wedge means for locking the second slider 20, which moves back by an increasing amount each time writing pressure is applied, at the retreated position. In front of the second slider, there is provided a third slider 26 which has a core guide tube 24 and is elastically biased rearward so as to come into contact with the front end of the second slider, and the core protrudes from the core guide tube. In writing without
The second slider moves back due to the pressure of the pen.
The slider is moved back to bring the lead into contact with the paper surface, and the chuck holding the lead is moved back together, and when the writing pressure is released, the second slider is locked at the retreated position by the wedge means, A sharp pencil in which the chuck that holds the lead moves forward to make the lead stick out.