JP2003285595A - Mechanical pencil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a lead guide ring is generally constituted of a rubber-like elastic material, and accordingly when a compressed state is maintained for a long period, the elastic material is remarkably hardened (generally called 'blooming'), projecting and retracting operation of a lead guide pipe or a feeding operation of the lead is hindered, and when the guide ring is hardened on its surface, a sliding resistance force to a nose is eliminated, the guide pipe is carelessly projected or retracted by its own weight or the guide pie is easily moved, and hence the lead is not fed. <P>SOLUTION: The mechanical pencil comprises a slide member disposed forward of a barrel. In this pencil, the barrel and the slide member longitudinally move in a state in which a slide resistance is imparted, but the slide resistance is released at the retracted position of the slide member. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical pencil having a slide member arranged in front of a barrel.

[0002]

2. Description of the Related Art As an example, Japanese Utility Model Publication No. 57-38311 will be described. In the utility model registration claim of the publication, "... the tip 2 having the second hollow portion 14 in which the chuck ring 5 is fitted and the first hollow portion 10 are brought into contact with the outer periphery, It is provided with a lead guide ring 11 holding a lead guide pipe 12 on the tip side which is press-fitted in a slidable manner, and the like. That is, the core guide ring 11 always slides in the first cavity 10 while being press-fitted.

[0003]

As described in the detailed description, the core guide ring is generally composed of a rubber-like elastic body, and therefore, the compressed state is long-term. Therefore, the hardening is extremely severe (generally referred to as blooming phenomenon, deterioration, aging, etc.), which hinders the operation of retracting the core guide pipe and the operation of extending the core. That is, if the surface of the core guide ring is hardened, the sliding resistance with the tip metal is lost, and the core guide pipe inadvertently appears or disappears due to its own weight, or the core guide pipe easily moves. Therefore, the core could not be extended.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a mechanical pencil having a slide member arranged in front of a barrel.
The shaft cylinder and the slide member move back and forth in a state where a sliding resistance is applied, but the gist is that the sliding resistance is released at the retracted position of the sliding member.

[0005]

The sliding resistance is imparted when the slide member is moving forward, but the sliding resistance is released in the retracted position.

[0006]

EXAMPLE A first example will be described with reference to FIGS. A core tank 2 is arranged in the shaft body 1 so as to be movable back and forth, and a chuck body 3 that can be opened and closed is provided at a front end of the core tank 2.
Is fixed. A chuck ring 4 for opening and closing the chuck body 3 is surrounded by a front portion of the chuck body 3. Further, an elastic member 5 such as a coil spring that biases these members backward is stretched between the core tank 2 and the inner surface step portion 6 of the shaft cylinder 1. The core tank 2, the chuck body 3, the chuck ring 4, the elastic member 5 and the like constitute the core feeding means 7 of the present invention. Further, an inner surface vertical rib 8 is provided on the front portion of the shaft body 1.
A tip member 8 in which a is radially formed is detachably fixed by means such as screwing, and a slide member 9 projecting from the tip thereof is slidably provided in the tip member 8. . A guide member 10 for guiding the core is provided inside the slide member 9, and a silicone rubber or N for holding the core lightly in front of the guide member 10 to prevent the core from retracting.
Although the core detent member 11 made of an elastic body such as BR is arranged, the guide member and the core detent member 11 may be integrally formed with the leading member. Further, a tubular portion 12 is formed on the rear side of the slide member 9, and a window hole 13 is formed in the tubular portion 12 at a position facing each other. Further, a slit is formed in the tubular portion 12 so as to be connected to the window hole 13 and can be expanded by an elastic deformation force when an external action is given to the tubular portion 12. A projecting portion 14 formed on the front outer periphery of the chuck body 3 is loosely inserted into the window hole 13.

An annular member (O-ring) 15 made of a rubber-like elastic material is provided on the outer peripheral surface of the intermediate portion of the slide member 9.
Is attached, but an elastic protrusion or the like may be integrally formed. When the slide member 9 is retracted (the state shown in FIG. 1), the annular member 15 has the leading member 8
Although it does not go into the inner surface vertical rib 8a, when the slide member 9 moves forward and the slide member 9 advances, the annular member 15 goes into the inner surface vertical rib 8a. At this time, the annular member 15 is in a state of being pressed against the inner surface vertical rib 8a. That is, the slide member 9 advances in a state where sliding resistance is imparted by the annular member and the inner surface vertical ribs. Here, the sliding resistance force of the slide member 9 with respect to the tip member 8 (inner surface vertical rib 8a) is set so that the core is larger than the sliding resistance force with respect to the core detent member 11, but the core tank 2 and It is set to be smaller than the resilient force of the resilient member 5 that biases the lead-out means 7 and the like backward. That is, even if the lead advances together with the chuck body 3, the movement of the slide member 9 is restricted with respect to the tip member 8. By the way, the core holding force of the core detent member is
20 gf to 100 gf is a suitable value, and if it is smaller than this value, there is a risk that the core will slip off, and conversely,
If it is high, there is a risk that the core cannot be extended. Further, the sliding resistance force of the annular member 15 with respect to the tip member 8 is 8
0 gf to 120 gf is preferable, and the elastic force of the elastic member 5 that biases the lead tank 2 and the like backward is 500 gf to 600 g.
f is common. In this example, the annular member 15 is slidably contacted with the inner surface vertical rib 8a formed on the tip member 8, but it may be changed to an inner surface vertical rib and simply slidably contacted with the cylindrical inner surface. In consideration of the unexpected deformation, compression of air due to sliding, etc., the rib shape is preferable. A step portion 16 is formed behind the inner surface of the tip member 8.
The chuck ring 4 is a restriction portion that prevents the chuck ring 4 from moving forward, and when the chuck ring 4 contacts the step portion 16,
The chuck body 3 is expanded and the gripped core is released.

Here, the chuck ring 4 has a step portion 15.
The distance up to the contact with the protrusion 14 of the chuck body 3 is
Is set to be smaller than the distance until it comes into contact with the front end of the window hole 13 of the slide member 9. That is, after the chuck ring 4 contacts the step portion 16 and the chuck body 3 expands, the protrusion 14 of the chuck body 3 contacts the front end portion of the window hole 13. More specifically, the chuck ring contact distance is smaller than the chuck body contact distance by 0.
It is set as short as 2 mm, but 0.1 mm to 1.0
If the difference is about mm, it works well. By the way, although the function can be achieved even with 1.0 mm, the amount of protrusion of the lead becomes large, and adjustment of the amount of protrusion of the lead afterwards becomes troublesome. Further, although a gap is formed between the cylindrical portion 12 of the slide member 9 and the shaft cylinder 1, the gap is smaller than the fitting distance between the chuck body 3 and the slide member 9. It is set. That is, when the projection 14 of the chuck body 3 is loosely inserted (assembled) into the window hole 13 of the slide member 9, the tubular portion 12 near the window hole 13 expands, but the tip member 8 is assembled to the shaft tube 1. After that, the expansion of the cylindrical portion 12 is restricted, and the loosely inserted state between the protrusion 14 and the window hole 13 is maintained. That is, the protrusion 14 does not slip out of the window 13.

A base portion 18 formed on a clip 17 is press-fitted and fixed to the rear portion of the shaft body 1, and an eraser 19 is detachably attached to the rear portion of the core tank 2. There is. Reference numeral 20 is a knock cap that covers the eraser 19, and is detachably attached to the rear portion of the lead tank 2. On the other hand, a grip member 21 made of a rubber material or the like is mounted in front of the barrel 1. The grip member 21 is mounted so as to straddle the recessed portion 1a formed in the barrel 1 and the recessed portion 8b formed in the tip member 8 to prevent the tip member 8 from loosening with respect to the barrel 1. The front member 8 can be grasped with a finger up to the front.

Next, the operation will be described. The state of FIG. 2 is a state in which the chuck body 3 holds the core A. The slide member 9 is pulled rearward by the protrusion 14 of the chuck body 3, and the annular member 15 is separated from the inner surface vertical rib 8a and is in a released state. That is,
It is in a state where no compressive force is applied. When the lead tank 2 is pushed forward from this state, the chuck ring 4
At the same time, the chuck body 3 and the lead A held by the chuck body 3 advance. At this time, since the lead A is lightly held by the lead detent member 11 of the slide member 9, the slide member 9 is also moved forward, but the annular member 15 abuts on the rear end of the inner vertical rib 8a, and , Slide member 9
In addition to the fact that the sliding resistance force on the tip member 8 is set to be large, a large amount of instantaneous compression force for entering (force for starting elastic deformation) is required, so the slide member 9 does not move ( 3), the core A is the detent member 1
It slides in 1 and projects from the tip of the slide member 9. Eventually, the chuck ring 4 contacts the stepped portion 16 of the tip member 8 and its forward movement is restricted (see FIG. 4). At this time,
A gap is formed between the protrusion 14 of the chuck body 3 and the front end of the window hole 13 of the slide member 9. Here, when the lead tank 2 further advances, the chuck body 2 slightly advances the lead A, and brings the projection 14 of the chuck body 3 into contact with the front end portion of the window hole 13 (see FIG. 5). At this time, the chuck body 3 expands to release the gripped core A,
The chuck body 3 may be opened at the moment when the chuck ring 4 contacts the step portion 16. When the lead tank 2 further advances, the protrusion 14 of the chuck body 3 moves the slide member 9 forward. At this time, the slide member 9
Moves forward while giving sliding resistance by the pressure contact action of the annular member 15 and the inner surface vertical rib 8a, but in this example, the sliding resistance force may be set to be extremely small. In the case of this example, the annular member 15 is the inner surface vertical rib 8a.
The most important action is the regulation (prevention) action at the moment of diving into. Therefore, the frictional force (sliding resistance) at the moment of compression is used. As a result, it becomes possible to prevent further deterioration with time due to the compressive deformation of the annular member. Eventually, the intermediate step portion 22 of the slide member 9
Comes into contact with the rear end 23 of the inner surface vertical rib 8a of the front member 8 and its forward movement is blocked (see FIG. 6).

Here, when the forward movement of the lead tank 2 is released, the chuck body 3 is retracted in the expanded state, but the slide member 9 is not retracted because resistance is given by the annular member 15. Eventually the protrusion 1 of the chuck body 3
When 4 comes into contact with the rear end portion of the window hole 13 of the slide member 9 (see FIG. 7), the backward movement of the slide member 9 is started. Eventually, the chuck body 3 is closed by the chuck ring 4 and grips the core A again (see FIG. 2). Further, since the window hole 13 of the slide member 9 is engaged with the protrusion 14 of the chuck body 3, the retracted position is maintained even after the pressing operation is released, and the window hole 13 of the slide member 9 falls by its own weight or the like, resulting in a trailing core. No gap is formed between B and the residual core A.

A second example will be described with reference to FIGS. This is an example in which the sliding resistance with respect to the inner surface vertical ribs 8a of the slide member 9 is given by the elastic protrusion integrally formed on the slide member 9. More specifically, an elastic piece 25 formed by cutting out in a U-shape (cutout portion 24) is formed on the side surface of the intermediate cylindrical portion of the slide member 9 at a position facing the elastic piece 25. A protrusion 26 is formed on the outer surface of the protrusion. The protrusion 26 corresponds to the annular member 15 of the previous example. And this protrusion 26
Is also released at the position where the slide member 9 is retracted, and when the slide member 9 is moved forward, it slides into the inner-surface vertical rib 8a to provide sliding resistance. Other configurations, operations, and the like are almost the same as the premise, and therefore description thereof will be omitted. A third example will be described with reference to FIG. It is an example in which the present invention is applied to a general mechanical pencil. Similar to the first example, the annular member 15 is provided at the middle portion of the slide member 27.
When the slide member 27 is retracted, the annular member 15 is located behind the inner surface vertical rib 8a. That is, the annular member 15 is in the released state. When the lead-out operation is performed from this state, the slide member 27 is pushed and moved forward by the front end portion of the chuck body 3, and at this time, the annular member 15 sinks into the inner surface vertical rib 8a to impart sliding resistance.

[0013]

According to the present invention, there is provided a mechanical pencil in which a slide member is disposed in front of a shaft cylinder, and the shaft cylinder and the slide member move back and forth in a state in which a sliding resistance is applied. In the retracted position, the sliding resistance is released, so that the function of the slide member is not lost for a long period of time, and thus a good lead-out can be obtained for a long period of time.

[Brief description of drawings]

FIG. 1 is a vertical half sectional view showing a first example.

FIG. 2 is an enlarged view of a main part with the core attached to FIG. .

FIG. 3 is a longitudinal sectional view of an essential part showing the operation.

FIG. 4 is a longitudinal sectional view of an essential part showing the operation.

FIG. 5 is a longitudinal sectional view of an essential part showing the operation.

FIG. 6 is a longitudinal sectional view of an essential part showing the operation.

FIG. 7 is a longitudinal sectional view of an essential part showing the operation.

FIG. 8 is a vertical cross-sectional view of a main part showing a second example.

FIG. 9 is a front view showing a slide member of a second example.

FIG. 10 is a side view of FIG.

FIG. 11 is a vertical cross-sectional view of a main part showing a third example.

[Explanation of symbols]

1-axis body 1a recess 2-core tank 3 chuck body 4 chuck ring 5 Repulsion member 6 Inner surface step 7-core feeding means 8 Tip member 8a inner rib 8b recess 9 Slide member 10 Core detent member 11 groove 12 Cylindrical part 13 windows 14 Projection 15 Annular member (O-ring) 16 steps 17 clips 18 base 19 eraser 20 knock cap 21 Grip member 22 Middle stage 23 Rear end 24 Notch 25 elastic pieces 26 Protrusion 27 Slide member

Claims (3)

[Claims] 1. A mechanical pencil in which a slide member is disposed in front of a shaft cylinder, wherein the shaft cylinder and the slide member move back and forth in a state where a sliding resistance is applied, but at a retracted position of the slide member. Is a mechanical pencil in which the sliding resistance is released. 2. The mechanical pencil according to claim 1, wherein an annular member made of a rubber-like elastic material is arranged between the barrel and the slide member, and the sliding resistance is imparted by the annular member. 3. A chuck body for gripping / releasing a lead is arranged behind the slide member, and a chuck ring for opening / closing the chuck body is surrounded in front of the chuck body and is provided on an outer surface of the chuck body. A protrusion is formed, and the protrusion is loosely inserted into a window hole formed in the slide member, and the moving distance of the chuck ring is set to be greater than the distance that the protrusion of the chuck body moves in the window hole of the slide member. The mechanical pencil according to claim 1, wherein the mechanical pencil is also reduced.