JP7445046B1 - lead used in mechanical pencils - Google Patents

Abstract

[Problem] To provide a lead used in a mechanical pencil that can be used even if the lead becomes short. [Solution] The lead 3b used in the mechanical pencil according to the present invention has hook-shaped engaging portions 8b formed on both end surfaces of the lead 3b, so that one lead and the other lead engage with each other. It is characterized by being connected to form a single core in appearance. [Selection diagram] Figure 11

Description

The present invention relates to a lead used in a mechanical pencil that can be used regardless of the position of the chuck and even if the lead becomes short.

Mechanical pencils have a structure in which the lead cannot be fixed once the lead is shortened to about 10-15 mm, so the lead that has become short and difficult to write with must be removed and a new lead taken out.A typical lead length is about 6 cm. So about 20% is wasted.

Specifically, a mechanical pencil is equipped with a device that grips and feeds the lead (hereinafter referred to as a chuck) and a device that receives the lead sent out by the chuck (hereinafter referred to as a detent).The structure of a typical chuck is as follows. The opening at the tip is divided into three parts, and each time you knock, the opening opens and sends out the wick, and at other times, the opening is closed and the wick is fixed.

Since these two devices (the chuck and the detent) have to be separated, when the lead becomes short, it can no longer be gripped by the chuck, and the lead is supported only by the detent.

In this manner, in a typical mechanical pencil, the lead is firmly fixed by being gripped by the chuck, and furthermore, the detent on the tip side receives and supports the lead sent out by the movement of the chuck.

Then, by knocking on the rear end side, the chuck moves and feeds out the lead, but if the lead becomes too short for the chuck to grasp, it will not be fixed by the chuck, but the next lead will be firmly fixed to the chuck. Since there is a core, it will be pushed by the next core.

It is not impossible to write letters even in this state, but it is difficult to write because the lead rotates or pops out, so this shortened lead has to be removed and the next one comes out. The core is not utilized and is wasted.

Furthermore, since the chuck and detent are separated, a space is created between the two devices, and in that space, the next lead pushes the shortened lead, so only the tips of each other touch, making it shorter. Even if you continue to use the core, if the shafts are not aligned perfectly, the force will not be concentrated in one point, and the core may break in this space.

Therefore, if this shortened lead can be used effectively, a technology has been disclosed as prior art that is thought to reduce waste of the lead and lead to eco-friendliness.

For example, the length of the remaining lead depends on the distance between the chuck and the detent, so as described in Patent Document 1, which is a technique related to the mechanical pencil structure such as the position of the chuck and the space for the chuck to move, A structure that allows the tip of the brush to be brought closer to the tip of the brush is disclosed.

Further, Patent Document 2 discloses a technique for using an adhesive as a core structure technique for reducing the amount of core remaining.

Japanese Patent Application Publication No. 2002-301894 Jitszen No. 59-041580

However, although the technology according to Patent Document 1 is excellent in that it can shorten the length of unnecessary remaining lead, the chuck is closer to the tip of the brush, which complicates the structure and may cause a malfunction. , there is a problem that the chuck near the tip of the brush makes the tip of the brush thick.

Furthermore, the technique disclosed in Patent Document 2 uses an adhesive, and is therefore difficult to call a practical solution.

In addition, since a general lead has a simple elongated cylindrical shape, the shortened lead is no longer fixed by the chuck, and when you try to write, it spins around, making it difficult to write.

As described above, currently there is no easy structure for mechanical pencils and leads that can be used even if the leads are shortened.

An object of the present invention is to provide a lead used in a mechanical pencil that can be used regardless of the position of the chuck and even if the lead becomes short.

In order to achieve the above objects, the present invention provides the following techniques.

In the invention according to claim 1 , by forming hook-shaped engaging portions on both end faces of the core, one of the cores and the other of the cores are engaged with each other and connected to each other, thereby forming a single core in appearance. To provide a lead used in a mechanical pencil, which is characterized by:

According to the invention described in claim 1 , by forming the hook- shaped engaging portions on both end faces of the core, one core and the other core are engaged with each other and connected to each other, so that the exterior appearance is a single core. Since the rear core is fixed by the chuck, not only can the shortened front core be prevented from rotating, but it can also be prevented from popping out .

FIG. 1 is a sectional view of a mechanical pencil according to an embodiment of the present invention. FIG. 2 is a sectional view showing a mechanical pencil according to an embodiment of the present invention with a lead inserted into a continuous pipe. FIG. 3 is a sectional view showing how the core shown in FIG. 2 is fed out. FIG. 2 is a sectional view showing a mechanical pencil according to an embodiment of the present invention with a lead inserted into a continuous pipe. FIG. 2 is a sectional view showing a mechanical pencil according to an embodiment of the present invention with a lead inserted into a continuous pipe. FIG. 2 is a perspective view showing a continuous pipe of a mechanical pencil according to an embodiment of the present invention. FIG. 1 is a perspective view showing a mechanical pencil chuck according to an embodiment of the present invention. FIG. 3 is a perspective view showing a state in which a chuck surrounds the outside of a continuous pipe and a grip protrusion is inserted into a grip opening. FIG. 2 is a perspective view of a concavo-convex core according to an embodiment of the present invention. FIG. 3 is a perspective view showing how the concave and convex cores are fitted together. FIG. 2 is a perspective view of a concave-convex hook-shaped core according to an embodiment of the present invention. FIG. 3 is a perspective view showing how the uneven hook-shaped cores are engaged with each other. FIG. 7 is a side view showing the length of the engaging portion of the uneven hook-shaped core. It is a side view which shows the curved part formed in the end surface of the engaging part of an uneven hook-shaped core.

The gist of the mechanical pencil according to the present invention is that it is a mechanical pencil that has a lead tank at the rear of the main body, and that feeds out the lead from the front by gripping and releasing the lead with a chuck inside that is linked to back and forth movement in the axial direction. A cylindrical continuous pipe with openings at both ends through which the core is inserted is fixed inside the main body from near the tip of the main body to at least the chuck along the axial direction, and the continuous pipe is inserted into the side surface of the midway part. The chuck is characterized in that a plurality of gripping openings consisting of openings are formed in the chuck, and the chuck slidably surrounds the continuous pipe, and a gripping protrusion that extends to the gripping opening and can come into contact with the core is formed on the inner wall on the tip side. shall be. In other words, even if the lead becomes short and cannot be gripped by the chuck, the lead is still firmly housed in the continuous pipe, so the pushing force of the next lead can be reliably transmitted to the shortened lead without wavering. It is an object of the present invention to provide a mechanical pencil and a lead that can be used in the mechanical pencil to achieve even greater effects.

Hereinafter, one embodiment of a mechanical pencil 1 and lead 3 according to the present invention will be described with reference to the drawings. Note that the "axial direction" in this description is the direction of the axis passing through the center of the mechanical pencil 1 in the longitudinal direction.

The mechanical pencil 1 according to the embodiment of the present invention is illustrated in FIGS. 1 to 5 (all cross-sectional views with the rear end side omitted, making it easy to understand that the gripping protrusion 7 formed on the chuck 5 grips the lead 3. (The angle of only the gripping protrusion 7 is changed to represent a cross section for convenience.) As shown in FIG. This is a mechanical pencil 1 in which a chuck 5 grips and releases the lead 3 to feed out the lead 3 from the front, and the lead 3 is inserted through a cylindrical continuous pipe 4 with openings at both ends along the axial direction of the main body 1a. The continuous pipe 4 is fixed inside the main body 1a from the vicinity of the tip to at least the chuck 5; A gripping protrusion 7 is formed on the inner wall on the distal end side, which freely surrounds the core 3 and extends into the gripping opening 6 so as to be able to come into contact with the core 3.

Further, the gripping openings 6 of the continuous pipe 4 are bored along the axial direction with a length that allows the chuck 5 to grip and release the core 3, and three openings are formed at equal angles around the axis. The chuck 5 consists of three chuck pieces 5a that surround the continuous pipe 4 from three directions at equal angles from the axial direction and the orthogonal direction, and each chuck piece 5a is formed with a gripping protrusion 7. ing.

Furthermore, the opening on the rear end side of the continuous pipe 4 is formed to communicate with the core tank 13.

Note that a detent 2, which is included in a conventional mechanical pencil, is formed on the tip side of the continuous pipe 4.

With this structure, even if the lead 3 becomes short and cannot be gripped by the chuck 5, the lead 3 is firmly housed in the continuous pipe 4, so the pushing force of the next lead 3' can be applied reliably without wavering. This can be transmitted to core 3, which has become shorter.

Although detailed description will be given below in detail with reference to the drawings, the cross-sectional views shown in FIGS. 1 to 5 show that the mechanical pencil 1 is rotated around its axis, excluding the spring 11 (and part of the chuck 5) The external shape of each part appears.

As shown in FIG. 1, the main body 1a of the mechanical pencil 1 according to the present embodiment is formed into a substantially cylindrical shape with a sharp tip and a detent 2 disposed at the tip, and a knock button (not shown) is provided at the rear end. The button engages with a push-in part 12 disposed inside the main body 1a, so that the push-in part 12 can be operated back and forth.

The detent 2 has a cylindrical shape with an insertion hole having an inner diameter that substantially matches the diameter of the core 3, and communicates with the tip of a continuous pipe 4 fixed in the axial direction inside the main body 1a.

Although the detent 2 does not necessarily have to be located at the tip of the main body 1a, it is desirable that it be placed at the tip of the continuous pipe 4.

The continuous pipe 4 has a long cylindrical shape with both ends open and has an inner diameter large enough to allow the core 3 to be inserted smoothly, and has a plurality of gripping openings 6 formed on the side surface of the middle part.

Specifically, as shown in FIG. 6, the grip opening 6 of the continuous pipe 4 is bored along the axial direction with a length that allows the chuck 5 to grip and release the core 3. Three locations are formed at equal angles around the axis.

The continuous pipe 4 is preferably made of a synthetic resin material in order to reduce its weight, but it may also be made of metal.

The periphery of the continuous pipe 4 fixed inside has a plurality of spaces serving as sliding chambers 14, and the distal end side of the main body 1a has an operation chamber 15 and a regulation chamber 16, and a rear part of the regulation chamber 16. A slide chamber 17 and an urging chamber 18 are formed in the slide chamber 17 .

The operation chamber 15 is a cylindrical space around the axis from which the gripping opening 6 of the continuous pipe 4 is exposed, and the regulation chamber 16 is a cylindrical space around the axis with a larger diameter than the inner diameter of the operation chamber 15. In the space, the rear end side of the gripping opening 6 of the continuous pipe 4 is exposed at the front.

Further, the regulation chamber 16 is provided with a distal end side of a chuck 5 that slidably surrounds the continuous pipe 4 and a chuck ring 10 that surrounds the chuck 5.

As shown in FIGS. 1, 7, and 8, the chuck 5 consists of three chuck pieces 5a that surround the continuous pipe 4 from three directions at equal angles from the axial direction and the orthogonal direction, and the outer shape of the tip side is While expanding outwardly, a gripping protrusion 7 extending into the gripping opening 6 and capable of abutting against the core 3 is formed on the inner wall.

In addition, the expanded tip side of the chuck 5, which is composed of three chuck pieces 5a, is formed to have an outer diameter that can extend into the operating chamber 15, and each chuck piece 5a is formed so as to generate a biasing force to open outward. are doing.

Note that the material of the chuck 5 is preferably a synthetic resin material in order to reduce the weight, but it may also be made of metal.

The chuck ring 10 has a cylindrical shape with a bottom, and has an insertion hole formed at the bottom through which the chuck 5 surrounding the continuous pipe 4 of the regulation chamber 16 is inserted, and the part on the distal end side where the chuck 5 expands serves as a front opening. The chuck pieces 5a are in contact with each other to restrict the movement of the chuck pieces 5a from opening outward.

Further, the chuck ring 10 is formed to allow slight back and forth movement in the regulation chamber 16. Specifically, the outer diameter of the chuck ring 10 is formed to be slightly smaller than the inner diameter of the regulation chamber 16, and The height of the chuck ring 10 is formed to be slightly lower than the height of the regulation chamber 16, and the front open end of the chuck ring 10 is formed so as to come into contact with a stepped portion between the regulation chamber 16 and the operation chamber 15.

Note that the material of the chuck ring 10 is preferably a synthetic resin material in order to reduce weight, but it may also be made of metal.

In this way, by forming the sliding chamber 14 (the operating chamber 15 and the regulation chamber 16), the continuous pipe 4, the chuck 5, and the chuck ring 10, the interior of the continuous pipe 4 is formed from the core tank 13 on the rear end side of the main body 1a. As shown in FIG. 2, the gripping protrusion 7 of the chuck piece 5a, which is inserted from the outside into the gripping opening 6 of the continuous pipe 4, can grip the core 3 from three equal directions. .

Furthermore, as shown in FIG. 3, by pressing a knock button on the rear end side (not shown), a push-in portion 12, which will be described later and engaged with the knock button, advances the chuck 5 into the operation chamber 15 within the range of the gripping opening 6. While the chuck 5 gripping the core 3 feeds out the core 3 forward, the chuck piece 5a opens toward the inner wall of the operating chamber 15, and the grip on the core 3 is released.

By repeating such an operation, it becomes possible to feed out the core 3 forward, and this is due to the following configuration.

At the rear of the regulation chamber 16, as shown in FIG. The biasing chamber 18 is a cylindrical space having an inner diameter slightly larger than the outer diameter of the tip end side of the pushing part 12 that surrounds and engages, and the biasing chamber 18 communicates with the rear thereof and is loosely inserted into the middle part of the pushing part 12. It is formed into a cylindrical space with an inner diameter slightly larger than the outer diameter of the spring 11.

That is, the inner diameter of the slide chamber 17 is smaller than the inner diameter of the biasing chamber 18.

The pushing part 12 is composed of a cylindrical front half and a cylindrical rear half having a larger outer diameter than the first half, and a core tank 13 is formed in the latter half.

Note that the material of the push-in portion 12 is preferably a synthetic resin material in order to reduce weight, but it may also be made of metal.

Further, the front inner circumferential wall of the front half surrounds and engages the rear end side of the chuck 5, and the inner circumferential wall of the front half surrounds and engages with the rear end side of the continuous pipe 4 so that the rear end side of the continuous pipe 4 can be slidably surrounded. It forms a step.

The spring 11, which is loosely inserted into the middle part of the push-in part 12 forming the front half, makes contact with the step where the slide chamber 17 and the biasing chamber 18 communicate with each other, and connects the front half and the rear half. The spring 11 can be held in the biasing chamber 18 by the rear part of the spring 11 coming into contact with the location (core tank 13).

With the above configuration, as shown in FIG. 3, when the knock button is pressed, the push-in portion 12 that engages with the knock button advances the chuck 5 into the operating chamber 15 against the biasing force of the spring 11, and the core While the chuck 5 gripping the core 3 feeds out the core 3 forward, each chuck piece 5a opens toward the inner wall of the operating chamber 15, and the grip on the core 3 is released.

Then, the pushing part 12 that engages with the chuck 5 returns to the rear by the biasing force of the spring 11, and at the same time each chuck piece 5a also returns to the regulation chamber 16, thereby completing one feeding operation.

By repeating such an operation, as shown in FIG. The front end abuts inside the continuous pipe 4 and acts virtually like a single lead, allowing writing to be performed without the leads wobbling each other.

As shown in FIG. 5, even if the front lead 3 becomes short, the back spare lead 3' is firmly gripped by the chuck 5, making it possible to write with force.

Next, as shown in FIGS. 9 to 14, the core according to the embodiment of the present invention has uneven engaging portions 8 formed on both end surfaces of the core, so that one core and the other core fit into each other. They are a concave-convex core 3a and a concave-convex hook-shaped core 3b that are formed so as to fit together or engage to form a single core in external appearance.

Specifically, the concave-convex core 3a shown in FIG. 9 has an engaging part 8 formed of a semicircular cut step (concave-convex part 8a), and FIG. 10 shows that the concave-convex cores 3a, 3a' It shows how it is.

With this configuration, even if the uneven core 3a becomes short and is no longer gripped by the chuck 5, the front short uneven core 3a that engages with the rear uneven core 3a' which is gripped and fixed by the chuck 5 will not rotate. You can write stably without any problems.

In addition, the uneven hook-shaped core 3b shown in FIG. ) By forming the engaging portion 8 into a hook shape, as shown in FIG. It consists of

With this configuration, not only rotation but also substantially fixation can be achieved by firmly engaging the uneven hook-shaped core 3b and the uneven hook-shaped core 3b'.

Therefore, with the mechanical pencil 1 and leads 3, (3a, 3b) according to the present invention, it is possible to continue writing even if the leads 3, (3a, 3b) become so short that they cannot be gripped by the chuck 5.

Note that the length t shown in FIG. 13 is the length required to form the engaging portion 8 (8b) consisting of a cut step at both ends of the uneven hook-shaped core 3b, and a length of about 2 mm is sufficient. .

Further, in FIG. 14, curved portions 9 made of roundness are formed on both end surfaces of the uneven hook-shaped core 3b so that the uneven hook-shaped cores 3b can be smoothly engaged with each other.

Note that the uneven lead 3a and the uneven hook-shaped lead 3b according to the present embodiment exhibit further sufficient effects when used in the mechanical pencil 1 according to the present embodiment, but they can also be used in other mechanical pencils. It goes without saying that it is possible.

As described above, the mechanical pencil 1 according to the present embodiment includes the lead tank 13 at the rear of the main body 1a, and inside the mechanical pencil 1, which is linked to the back and forth movement in the axial direction, the chuck 5 grips and releases the lead 3. This is a mechanical pencil 1 in which a lead 3 is fed out from the front, and a cylindrical continuous pipe 4 with open ends through which the lead 3 is inserted is inserted along the axial direction from near the tip of the main body 1a to at least the chuck 5. The continuous pipe 4 is fixedly installed inside the pipe 1a, and the continuous pipe 4 has a plurality of gripping openings 6 formed on the side surface of the middle part, and the chuck 5 slidably surrounds the continuous pipe 4, and has a gripping opening 6 on the inner wall on the tip side. By forming the gripping protrusion 7 that extends into the gripping opening 6 and can come into contact with the lead 3, it is possible to prevent the axes of the shortened lead 3 and the next lead 3' from wobbling, so that the lead 3 becomes shorter. Even if the lead 3 cannot be gripped by the chuck 5, it is firmly housed in the continuous pipe 4, so that the pushing force of the next lead 3' can be reliably transmitted to the shortened lead 3 without wavering.

Further, the gripping openings 6 of the continuous pipe 4 are bored along the axial direction with a length that allows the chuck 5 to grip and release the core 3, and three openings are formed at equal angles around the axis. The chuck 5 consists of three chuck pieces 5a that surround the continuous pipe 4 from three directions at equal angles from the axial direction and the orthogonal direction, and each chuck piece 5a is provided with a gripping protrusion 7. Therefore, the gripping protrusion 7 formed on the chuck 5 can grip the core from three directions in the gripping opening 6 of the continuous pipe 4 into which the core 3 has been inserted, thereby fixing the core 3.

In addition, since the opening on the rear end side of the continuous pipe 4 is in communication with the wick tank 13, when the wick 3 at the front in the continuous pipe 4 is fed out, spare wicks 3 stocked in the wick tank 13 can be used. ' can be smoothly led out into the continuous pipe 4.

In addition, by forming the uneven core 3a according to this embodiment and the uneven engaging portions 8 (8a) on both end faces of the core, one uneven core 3a and the other uneven core 3a' fit into each other, resulting in an appearance. Since the rear concavo-convex core 3a' is fixed by the chuck 5 since it becomes a single core in sight, it is possible to prevent the shortened front concave-convex core 3a from rotating.

Furthermore, by forming the engaging portion 8 (8b) in a hook shape, one uneven hook-shaped core 3b and the other uneven hook-shaped core 3b' engage with each other and are connected to each other, so that the unevenness becomes shorter. Not only can the hook-shaped core 3b be prevented from rotating, but it can also be prevented from popping out.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention as described in the claims. is possible.

1 mechanical pencil 1a main body 2 detent 3 lead 3' spare lead 3a uneven lead 3b uneven hook-shaped lead 4 continuous pipe 5 chuck 6 gripping opening 7 gripping protrusion 8 engaging part 8a uneven part 8b uneven hook-shaped part 9 curved part 10 Chuck ring 11 Spring 12 Pushing part 13 Core tank 14 Sliding chamber 15 Operating chamber 16 Regulation chamber 17 Slide chamber 18 Biasing chamber

Claims (1)

A sharpener characterized in that by forming hook-shaped engaging portions on both end faces of the lead, one of the leads and the other of the leads engage and connect with each other to form a single lead in appearance. Lead used in pencils.

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