JP2002362088A - Mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently contain leads of a mechanical pencil of a thick diameter even in the case of a distal barrel or a rear barrel of fine specifications and to provide a mechanical pencil of an eraser feeding type a lead color and a residual amount of a lead permitting to be easily confirmed. SOLUTION: The mechanical pencil comprises an eraser feeder detachably mounted at a rear of a distal barrel. The pencil further comprises a bar-like coupler arranged between the eraser feeder and a chuck. A front end of the coupler is integrated with or fixed to a barrel joint provided at a rear end of the chuck, and a rear end of the coupler is contacted with an inner stepped part of the barrel at the front of the eraser feeder. Further, an engaging part provided in the vicinity of the rear end of the coupler is engaged with the inner wall of the barrel. When the feeder is knocked to the distal barrel to enable the lead to be fed so that a space between the feeder and the chuck becomes a lead housing section.

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 an eraser dispenser.

[0002]

2. Description of the Related Art Conventionally, a rear shaft is rotated with respect to a front shaft to feed out a large-diameter eraser from the rear end of the rear shaft, and the rear shaft is knocked at the rear end of the front shaft to feed a core. A mechanical pencil having an eraser dispenser is known.
In addition, a normal eraser unreeling body is composed of a combination of a rear shaft, an inner cylinder, and an eraser holder.The front cylinder portion of the inner cylinder is fitted to the outer periphery of the core case, and the outer periphery of the cylinder portion is attached to the inner surface of the front shaft. It is freely rotatable back and forth, and the inner surface of the rear shaft is fitted on the outer circumference of the front shaft.The rotation of the rear shaft with respect to the front shaft causes the eraser holder to move back and forth and the eraser from the rear end. It is configured to be able to come and go freely. Therefore, when the rear shaft, the front shaft, the cylindrical portion in front of the inner cylinder, and the core case are overlapped, when the front shaft and the rear shaft are thin, the inner diameter of the core case is small, and a sharp core with a large core diameter is required. There is a problem that cannot be built in sufficiently. In addition, to confirm the core color and the remaining amount of the core, the front shaft and the core case may be made of a transparent resin molded product, but it is very difficult to see through the two separated cylinders and it is satisfactory. Was not.

Conventional pencil leads can be roughly classified into the following four types of manufacturing methods, but all of them have disadvantages when used as colored sharp leads. That is, (1) a fired pencil lead obtained by kneading, molding, and then firing the mixture, which is mainly composed of graphite as a coloring agent, an organic substance, clay, or the like as a binder. The pencil lead obtained by this method has recently reached a sufficient practical strength even for a pencil lead, and is known as a pencil lead that can be erased with an eraser. However, there is a drawback that a pencil lead other than black cannot be manufactured due to the colors of graphite and calcined carbon material used.

(2) A non-fired pencil lead obtained by kneading and molding a wax, a binder, a filler, a pigment, and the like. According to this production method, various kinds of organic pigments can be used, light resistance and weather resistance are good, and a color pencil lead having a vivid hue can be obtained. However, this colored pencil core is not fired and relies mainly on bonding with an organic binder. Therefore, when it is used as a mechanical pencil lead, sufficient strength cannot be obtained, and since it contains waxes, it cannot be erased with an eraser. There are drawbacks that can not be done.

(3) Water- and oil-repellent substances, binders, body materials,
A non-fired pencil lead obtained by kneading and molding a pigment or the like, and further impregnating the open pores formed around the water / oil repellent substance with oils and fats.
According to this production method, when a liquid oil or the like at room temperature is selected as the oils and fats to be impregnated, it is possible to produce a colored pencil lead that can be easily erased with an eraser to the same extent as in (1) above. However, in the case of using a color pencil lead of a vivid hue using an organic pigment, a binder that can be used is limited to an organic polymer substance or the like due to the heat resistance of the pigment, and thus a fine lead such as for a mechanical pencil is used. In this case, there is a disadvantage that sufficient strength cannot be obtained.

(4) A pencil lead obtained by impregnating a light-colored or white fired porous pencil lead obtained by kneading, molding and firing boron nitride, clay, an organic substance and the like with a dye ink.
The line drawn by the pencil lead obtained by this method can be erased with an eraser. However, since clay is used as the binder, the strength is not sufficient as compared with the core of the above (1).

[0007] As an improvement of (4), by kneading, extruding and baking in a non-oxidizing atmosphere a compounded composition containing at least a body material and an organic excipient, the organic excipient is carbonized. Forming a first fired core using the obtained carbide as a binder, and heating the first fired core in an oxidizing atmosphere to form a second fired core made of at least a constitutional material by oxidizing and removing the binder of the carbide; A third fired core body in which pores of the second fired core body are impregnated with a perhydropolysilazane-containing liquid and heat-treated in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere to produce silicon nitride. And a high-strength fired sharp core obtained by coloring the third fired core with a coloring agent having excellent light resistance and weather resistance is obtained. In the obtained third fired core, silicon nitride as a binder is finely and uniformly dispersed in the core, and is generated. Further, since the body material is highly oriented, a small amount of silicon nitride is generated. It is easy to develop the strength of the core, and the collapse of the core during writing is uniform.

[0008]

SUMMARY OF THE INVENTION The present invention makes it possible to sufficiently incorporate a sharp core having a large core diameter even if the front shaft or the rear shaft has a narrow specification, and it is easy to confirm the core color and the remaining amount of the core. It is possible to provide a mechanical pencil that can be supplied with an eraser.

[0009]

The present invention has the following arrangement to achieve the above object. The mechanical pencil according to claim 1 is a mechanical pencil in which an eraser feeding body is detachably attached to the rear of the front shaft, wherein a rod-shaped connecting tool is disposed between the eraser feeding body and the chuck, By knocking the eraser feeding body with respect to the front shaft, the core can be fed, and a space between the eraser feeding body and the chuck is formed as a core housing portion.

[0010] A mechanical pencil according to a second aspect of the present invention is the mechanical pencil according to the first aspect,
The front end of the connecting tool is integrally or fixedly attached to a shaft joint provided at the rear end of the chuck, and the rear end of the connecting tool is in contact with the inner step of the cylindrical portion in front of the eraser feeding body, and further near the rear end of the connecting tool. Is provided with an engaging portion that engages with the inner wall of the cylindrical portion.

A mechanical pencil according to a third aspect of the present invention is the mechanical pencil according to the first aspect,
The tip shaft is provided transparently, and the core accommodating part has a built-in colored sharp core, in which a porous fired core body is impregnated with dye or pigment ink, and writing lines can be easily erased with an eraser. The eraser attached to the feeding body is provided in substantially the same color as the coloring written with a colored sharp core.

[0012]

FIG. 1 shows a first embodiment of the present invention. First, a tip pipe 6 through which a core can be inserted is inserted into the tip of the base 5.
A holding chuck 7 made of rubber or the like, through which the core is appropriately frictionally engaged and inserted, is fixed to the end of the inner hole.
In addition, a screw portion (female screw) having a step 8 at the end is provided behind the inner hole of the base 5.

The front shaft 1 is a transparent resin molded product. A shaft portion 2 having a screw portion 3 (male screw) is provided at the tip of a cylindrical body, and a hole having a step portion 4a is provided in the shaft portion 2. The hole communicates with the inner hole at the rear of the cylinder. A step 4b is provided at the tip of the inner hole. Further, the rear end hole of the front shaft 1 communicating with the inner hole portion is provided with an engaging portion 1a such as a polyhedral shape or a rib-groove relationship or the like, which is rotationally engaged with a tube portion 23 of an inner tube 19 described later. Is provided. However, the inner cylinder is movable in the axial direction with respect to the front shaft.

By the way, the chuck 9 is inserted into the hole of the shaft portion 2 of the front shaft 1 by engaging the head with the fastener 13, and the rear end of the chuck 9 is fixed to the shaft joint 11. The shaft coupling 11 has a core guide portion 12 at the inner rear end thereof, and further has a hole through which the sharp core 27 is inserted in the chuck. When the shaft joint 11 is fixed to the rear end of the chuck, a spring 14 is laid between the step 4b of the front shaft 1 and the front end of the shaft joint 11 to urge the chuck 9 rearward of the front shaft 1. Have been.

Further, the eraser feeding member is constituted by combining members of a rear shaft 15, an inner cylinder 19, and an eraser holder 24. The rear shaft 15 has an inner hole which is fitted forwardly on the outer periphery of the rear end of the front shaft 1. A step 17 is formed at the rear end of the inner hole. A clip 18 is provided on the side surface, and a spiral groove 16 is formed on the inner surface. The inner cylinder 19 is provided with a collar-shaped locking portion 21 at an outer peripheral portion substantially at the center thereof, and has a rear cylindrical portion having a hole through which an eraser 26 is inserted, and a rear end thereof abutting on a rear end surface of the rear shaft 15. It has a crown portion 20, and further, a long slit portion 22 is formed at two places on the side surface of the rear tubular portion toward the crown portion 20. Further, a tubular portion 23 is integrally provided in front of the locking portion 21, and an engaging portion is formed on the outer periphery of the tubular portion 23 so as to engage with the rear end hole of the above-mentioned front shaft 1 to prevent rotation. .

Further, the eraser dispenser is provided with the inner cylinder 19.
The eraser holder 24 is resiliently fitted from the slit portion 22 so that the engagement protrusion 25 provided on the side surface thereof is fitted into the slit portion, and the inner cylinder 19 is moved from the rear end of the rear shaft 15 to the engagement protrusion 25. Insert while inserting into the spiral groove 16,
The locking portion 21 is locked to the step 17 of the rear shaft 15 by elastic deformation, so that the rear shaft 15 is rotatable with respect to the inner cylinder 19 between the crown 20 and the step 17 and is prevented from falling off. . An eraser 26 is fixed to the rear end of the eraser holder 24.

On the other hand, the front end of the connecting member 10 is integrally or fixedly attached to a shaft joint 11 provided at the rear end of the chuck 9, and a contact portion 10 b is provided at the rear end of the connecting member 10 by bending. A protruding engagement portion 10a is provided near the rear end of the tool 10.

[0018] In this state, the eraser feed-out body is connected to the front shaft 1
And the cylindrical portion 23 of the inner cylinder 19 is
And the contact portion 10b provided at the rear end of the connecting member 10 is brought into contact with the inner step portion 23a of the cylindrical portion 23, and further provided near the rear end of the connecting member 10. Engaging part 10
a frictionally engages with the inner wall of the cylindrical portion 23. The engaging means is not limited. As described above, when the rear shaft 15 is rotated with respect to the front shaft 1, the eraser 26 protrudes and retracts from the rear end hole of the crown 20.

FIG. 2 shows a second embodiment of the present invention. Hereinafter, only differences from the first embodiment will be described. First, the rear end hole of the front shaft 1 is provided with an engaging portion having a polyhedral shape or a rib-groove engaging relationship or the like, which is rotationally engaged with a cylindrical portion 31 described later. However, the cylindrical portion 31 is movable in the axial direction with respect to the front shaft 1. (However, there is no necessity to stop the rotation of the cylindrical portion 31 and the front shaft 1. It is more convenient that the rotation is stopped in operation.)

The eraser dispensing body is constituted by combining members of a rear shaft 30 and an eraser holder 38. First, a slit 34 is provided on the side surface of the rear shaft 30, and a projection 35 is formed on at least one wall of the slit 34.
And grooves 36 are provided alternately.

On the other hand, the eraser holder 38 has a bottomed cylindrical holding portion 39 for fastening the rear end of the eraser 44 at the rear, and a hole 40 is provided at the bottom. An elastic piece 41 having a notch and being displaceable is provided on one side of the front cylindrical portion of the eraser holder 38, and an operation button 42 having a locking projection 43 is formed at the tip of the elastic piece 41. I have.
The crown 37 has a hole having a portion that can be fixed to the rear end of the rear shaft 30 and a rear end hole through which the eraser 44 can appear and disappear.

Further, an eraser holder 38 is inserted from the rear end of the rear shaft 30, and the operation button 42 is projected outward from the slit 34, and the locking projection 43 is locked in the groove 36. In this state, the locking projection 43 is blocked by the projection 35 of the slit, so that the eraser holder 38 is prevented from moving back and forth. When the operation button 42 is appropriately pressed, the engagement between the locking projection 43 and the groove 36 is released, and in this state, the operation button 42 is moved back and forth to move the eraser holder 38. Further, the eraser 44 is fixed to the holding portion 39 of the eraser holder 38. A crown 37 is fixed to the rear end of the rear shaft 30. Rear shaft 3
A cylindrical portion 31 having a rear end portion integrally connected by a wall portion 32 to the front inner hole portion 0 extends forward. In addition, a partition-like inner step portion 33 that receives the rear end of the core is provided at the rear end of the inner hole of the cylindrical portion 31.

As described above, the eraser feed-out body is inserted into the rear end hole of the front shaft 1, the cylindrical portion 31 is engaged with the front shaft 1 so as to prevent rotation, and the contact portion provided at the rear end of the connecting tool 10 is provided. Part 10b
Is brought into contact with the inner step 33 of the tubular portion 31, and
The engagement portion 10a provided near the rear end of the cylinder portion frictionally engages with the inner wall of the cylindrical portion 31. As described above, when the operation button 42 is slid with respect to the rear shaft 30, the eraser 44 protrudes and retracts from the rear end hole of the crown 37.

[0024]

In the case of Embodiment 1 In order to extend the core, the front shaft 1 is gripped, the rear end of the crown portion 20 at the rear end of the rear shaft 15 is axially shifted (knocked), and the associated chuck 9 is advanced to advance the core. Pay out. When the rear shaft 15 is rotated with respect to the front shaft 1, the eraser 26 protrudes and retracts from the rear end of the crown 20. In the case of Embodiment 2 When the operation button 42 is moved back and forth with respect to the rear shaft 30, the eraser 44 comes out from the rear end of the crown 37.

Further, by disposing the rod-shaped connecting member 10 between the eraser feeding member and the chuck 9, the space between the eraser feeding member and the chuck 9 becomes a core receiving portion.
The built-in core 28 can be stored directly in the inner hole of the front shaft. Therefore, even if the front shaft and the rear shaft are thin, it is possible to sufficiently incorporate a sharp core with a large core diameter, and since the core can be seen directly from the outer wall of the transparent front shaft, the core color and core You can easily check the remaining amount. Also, a porous sintering core is impregnated with a dye or pigment ink, and a colored sharp core, which makes it easy to erase the writing line with an eraser, and an eraser with good erasability for the core are provided in substantially the same color as the colored sharp core. This makes it possible to improve the display properties and to make the eraser less conspicuous by erasing with the same colored sharp core.

[0026]

The configuration and operation of the mechanical pencil according to the present invention are as described above. A sharp core having a large core diameter can be sufficiently incorporated even in a thin specification of the front shaft and the rear shaft. It is possible to provide an eraser feeding type mechanical pencil that allows easy confirmation of the remaining amount of the core. In addition, by providing a colored sharp core and an eraser having good erasability for the core in substantially the same color as the colored sharp core, the display properties are improved, and the stains due to erasure by the same colored sharp core of the eraser can be made inconspicuous. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mechanical pencil that is Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of a mechanical pencil that is Embodiment 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front shaft 1a Engagement part 2 Shaft part 3 Screw part 4a Step part 4b Step part 5 Base 6 Tip pipe 7 Holding chuck 8 Step part 9 Chuck 10 Connector 10a Engagement part 10b Contact part 11 Shaft joint 11a Hole part 12 Core guide part 13 Fastener 14 Spring 15 Rear shaft 16 Spiral groove 17 Step part 18 Clip 19 Inner cylinder 20 Crown part 21 Locking part 22 Slit part 23 Tube part 23a Inner step part 24 Eraser rubber holder 25 Engagement protrusion 26 Eraser 27 Sharp core 28 Built-in core 30 Rear shaft 31 Cylindrical part 32 Wall part 33 Inner part 34 Slit 35 Projection 36 Groove 37 Crown 38 Eraser rubber holder 39 Nipping part 40 Hole 41 Elastic piece 42 Operation button 43 Locking projection 44 Eraser

Claims (3)

[Claims] 1. A mechanical pencil in which an eraser feeder is detachably mounted behind a front shaft, a rod-shaped connecting member is disposed between the eraser feeder and the chuck, and the rod is connected to the front shaft. A sharp pencil characterized in that a core can be extended by knocking the eraser feeding body, and a space between the eraser feeding body and the chuck is formed as a core receiving portion. 2. A front end of the connecting tool is integrally or fixedly attached to a shaft joint provided at a rear end of the chuck, and a rear end of the connecting tool is brought into contact with an inner step portion of a cylindrical portion in front of the eraser feeding body, and further connected. 2. The mechanical pencil according to claim 1, further comprising an engagement portion which engages with an inner wall of the cylindrical portion near a rear end of the tool. 3. A colored sharp core in which a leading axis is provided transparently, and a porous fired core body is impregnated with a dye or pigment ink and a writing line can be easily erased with an eraser is provided in a core accommodating portion. 2. The mechanical pencil according to claim 1, wherein the eraser built in and attached to the eraser feeder is provided in substantially the same color as the color developed by writing with a colored sharp core.