JPH1111077A - Mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an eraser-delivery type mechanical pencil having positively breakage prevention at the period of refilling colored mechanical pencil refills, and an erasing property in the eraser. SOLUTION: This includes a chuck 9 provided at the tip end of a tip spindle to be retractable by a spring 14, a spindle coupler 10 set at the rear end of the chuck, wherein an eraser delivering body has a cap 15 provided with a spiral groove 16 on the inner hole and a slit 22 at the rearward sleeve side surface to be secured rotatably by its rear part within the cap inner hole, an inner sleeve 19 being integrally provided with an elongated refill case part at the front part and an eraser holder 24 with an eraser fixed stationarily at its rear end, a projection made to be fitted in the slit of the inner sleeve and spiral groove of the cap, or the refill case mentioned above is spinde- shiftable with respect to the tip spindle and includes a part being stopped in rotation interactively. In this way, the mechanical pencil is formed by having colored refills held in the refill case and a tip end of the refill case part secured detachable at the rear end of the spindle coupler, and by allowing the cap to rotate with respect to the tip spindle, an eraser freely comes in and out from the rear end.

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 a large-diameter eraser from a rear end of the rear shaft, and a rear shaft is knocked at a rear end of the front shaft to feed a core. Mechanical pencils are known. Conventional pencil leads can be roughly classified into the following four types of manufacturing methods, but all of them have drawbacks when used as colored sharp leads.
That is,

[0003] (1) A fired pencil lead obtained by kneading, molding, and then firing the mixture, which comprises 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, when using an organic pigment as a color pencil lead with a vivid hue, the binder used is limited to organic polymer substances and the like because of the heat resistance of the pigment. 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] However, although the colored sharp core has reached a practical level, the strength of the core and the erasability with an eraser are not sufficient as compared with the black sharp core. Also, there is a problem of how easy to classify as a mechanical pencil, such as the difference between the color tone of the core itself and the written color tone and the differentiation of similar colors.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to an eraser feed-out mechanical pencil which ensures breakage prevention when refilling a colored sharp lead and ensures erasability with an eraser, and which can easily identify the lead color. It can be provided.

[0010]

The present invention has the following arrangement to achieve the above object. The mechanical pencil according to claim 1 is provided with a chuck provided at the tip of the front shaft so as to be pulled backward by a spring, a shaft joint at a rear end of the chuck, and an eraser feeding body,
A cap provided with a spiral groove in the inner hole, a slit provided on the side surface of the rear cylindrical portion, a rear portion rotatably fastened by the cap inner hole, and a long core case portion provided integrally in the front portion. A cylinder, an eraser holder having a projection on the side surface inside the inner cylinder and an eraser fixed at the rear end is inserted, and the projection is provided so as to fit into the slit of the inner cylinder and the spiral groove of the cap, The core case portion is provided with a portion that can be axially shifted with respect to the front shaft and is prevented from rotating between each other,
With the above, the tip of the core case portion is detachably fastened to the rear end of the shaft joint to constitute the mechanical pencil,
By rotating the cap with respect to the front shaft, the eraser can freely come and go from the rear end.

A mechanical pencil according to a second aspect of the present invention is the mechanical pencil according to the first aspect,
A colored sharp lead is built in the lead case, and the lead case and the tip shaft are provided transparently.

A mechanical pencil according to a third aspect of the present invention is the mechanical pencil according to the first aspect.
A colored sharp lead is incorporated in the lead case part, the lead case part is provided entirely or partially in the same color as the color developed by writing with the colored sharp lead, and the leading axis is provided transparently.

A mechanical pencil according to a fourth aspect of the present invention is the mechanical pencil according to any of the first to third aspects, wherein the colored sharp core is easily erased with an eraser.

[0014]

1 and 2 show an embodiment of the present invention. First, a tip pipe 6 through which a core can be inserted is fixed to the tip of the base 5, and 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. Further, a screw portion (female screw) having a step portion 8 at the end is provided behind the inner hole of the base 5.

The front shaft 1 is provided with a shaft portion 2 having a screw portion 3 (male screw) at the end of a cylindrical body, and the shaft portion 2 is provided with a hole having a stepped portion 4a, and the hole is formed at the rear. Of the cylindrical body. 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 a polyhedral shape or a rib-groove engagement relationship for mutually preventing rotation engagement with an engagement portion 23a of the inner cylinder 19 described later. Have been. However, the inner cylinder is movable in the axial direction with respect to the front shaft.

By the way, the fastener 1 is inserted into the hole of the shaft 2 of the front shaft 1.
The chuck 9 is fitted with the head engaged with 3, and the shaft coupling 10 is fixed to the rear end of the chuck 9. The shaft coupling 10 has a flange 11 on the outer periphery, a core guide 12 at the rear end, and further has a hole through which the sharp core 27 is inserted into the chuck. When the joint is fixed to the rear end of the chuck,
A spring 14 is urged between the step 4b of the front shaft and the flange 11 of the shaft joint.

Further, the eraser dispensing body includes a cap 15,
The cap 15 is formed by combining members of an inner cylinder 19 and an eraser holder 24. The cap 15 is provided with an inner hole which is fitted on the outer periphery of the rear end of the front shaft 1, and a step 17 is formed at the rear end of the inner hole. ing. A clip 18 is provided on a side surface, and a spiral groove 16 is formed on an inner surface. The inner cylinder 19 is provided with a flange-shaped locking portion 21 at a substantially central outer peripheral portion, and a rear cylinder portion has a hole through which an eraser 26 is inserted and a rear end of the inner cylinder 19 abutting on the rear end surface of the cap 15. It has a crown portion 20, and long slits 22 are formed at two locations on the side surface of the rear cylindrical portion toward the crown portion 20. In addition, a long cylindrical core case portion 23 is integrally provided in front of the locking portion 21. Further, the above-described front shaft 1 is attached to the outer peripheral portion of the rear end of the core case portion 23.
An engagement portion 23a is formed which engages with the rear end hole to stop rotation.

The eraser dispensing body is configured such that an eraser holder 24 is elastically fitted from the slit 22 of the inner cylinder 19 to engage an engagement projection 25 provided on a side surface of the eraser holder 24 with the cap 15. The engaging projection 25 is inserted into the spiral groove 16 from the rear end thereof while being engaged with the spiral groove 16, and the locking part 21 is locked to the step part 17 of the cap 15 by elastic deformation. The inner cylinder 19 is rotatable with respect to the portion 17 and is prevented from falling off. An eraser 26 is fixed to the rear end of the eraser holder 24.

In this state, the eraser feeding body is inserted into the rear end hole of the front shaft 1, and the front end hole of the core case portion 23 of the inner cylinder is detachably attached to the outer peripheral portion of the rear end of the shaft joint 10. Is done. As described above, when the cap 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. An opening / closing part is provided at the tip of the core case part so that the built-in core does not fall off. It is also possible to provide joints.

In the first embodiment, the core case 2
3 has a colored sharp core built therein, and at least the core case 23 and the tip shaft 1 are transparently provided.

As a second embodiment, a colored sharp core is incorporated in the core case portion 23, and at least the core case portion 23 is provided as transparent or entirely or partially in the same color as the color written with the colored sharp core. The front shaft 1 is provided as transparent. Making a part of the lead case part transparent means that the presence of the built-in lead 28 can be seen through from the outside. or,
As means for partially transparentizing, it is possible to double-mold a transparent and colored resin, or to paint a transparent cylindrical portion.

In a third embodiment, a colored sharp lead that can be easily erased with an eraser is incorporated in the lead case portion 23.

[0023]

First, in order to advance the lead, the front shaft 1 is gripped, the rear end of the crown portion 20 at the rear end of the cap 15 is axially shifted (knocked), and the associated chuck 9 is advanced to advance the lead.
When the cap 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 addition, since the lead case portion 23 is integrated with the eraser feeding member, a combination of a colored sharp lead and an eraser with good erasability for the lead can be specified, and the lead case portion can be detachably attached. Thus, it is possible to specify a combination of chuck mechanisms suitable for the properties of the core.
In addition, by using a specific unit so that refilling of the core alone is not performed, the problem of breakage of the core when refilling the core is solved. That is, it is possible to solve the problem that the strength of the lead and the erasability of the eraser are not sufficient when a colored sharp lead is mounted on an arbitrary mechanical pencil.

By making the lead case portion 23 and the tip shaft 1 transparent, the presence of the lead can be seen through. Further, if the tip shaft is made transparent and the lead case portion is colored the same as the written color tone of the lead, the difference between the color tone of the lead itself and the written tone and the differentiation of similar colors can be easily identified. Also, it has excellent display properties. If a part of the lead case is made transparent, the presence of the lead can be confirmed.

[0026]

The construction and operation of the mechanical pencil according to the present invention are as described above. This ensures the prevention of breakage when refilling a colored sharp lead and the erasability with an eraser, and makes it easy to identify the lead color. It is possible to provide an eraser feeding type mechanical pencil excellent in display performance.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mechanical pencil according to an embodiment of the present invention.

FIG. 2 corresponds to FIG. 1 and shows a state in which a colored part having the same color tone as that of writing on the lead and a transparent part capable of confirming the presence of the lead are provided on the lead case.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 front shaft 2 shaft portion 3 screw portion 4a step portion 4b step portion 5 base 6 tip pipe 7 holding chuck 8 step portion 9 chuck 10 shaft joint 11 flange portion 12 core guide 13 fastener 14 spring 15 cap 16 spiral groove 17 step portion Reference Signs List 18 clip 19 inner cylinder 20 crown part 21 locking part 22 slit 23 core case part 23a engaging part 24 eraser holder 25 engaging protrusion 26 eraser 27 sharp core 28 built-in core 29 coloring part 30 transparent part

Claims (4)

[Claims] 1. A mechanical pencil in which an eraser feeding body is detachably mounted behind a front shaft, a chuck provided at a tip of the front shaft so as to be pulled rearward by a spring, and a rear end of the chuck. A shaft coupling is provided in the cap, and the eraser unwinder has a cap with a spiral groove in the inner hole and a slit on the side surface of the rear cylinder. An inner cylinder with a long core case part integrally provided with an eraser holder with a projection on the side and an eraser fixed at the rear end is inserted into the inner cylinder, and the projection has a slit and cap of the inner cylinder Is provided so as to fit into the spiral groove of the core case, and the core case portion is provided with a portion which can be axially shifted with respect to the front shaft and is prevented from rotating between each other. Above joint The mechanical pencil is detachably fastened to a rear end of the mechanical pencil, and the eraser is allowed to protrude and retract from the rear end by rotating a cap with respect to a front shaft. 2. The mechanical pencil according to claim 1, wherein a colored sharp lead is incorporated in the lead case part, and the lead case part and the tip shaft are provided transparently. 3. A method in which a colored sharp lead is incorporated in the lead case part, the lead case part is provided entirely or partially in the same color as the color developed by the colored sharp lead, and the tip shaft is provided in a transparent manner. The mechanical pencil according to claim 1, wherein: 4. The mechanical pencil according to claim 1, wherein the colored sharp core can be easily erased with an eraser.