JPH0920098A - Multiple type writing tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multiple type writing tool with which writing and erasing can be done easily by making at least one writing body out of writing bodies house a coloring sharp lead other than black and arranging an eraser holder movably back and forth in a back barrel. SOLUTION: When a back barrel 4 is rotated in one direction with respect to a tip barrel 3 or an internal barrel 1, a notch 15 provided at a tip of a cam slant face 14 of a cylindrical cam 5 engages with a sliding piece 6 of a mechanical pencil writing body 7 having a coloring sharp lead other than black which can be easily erased by one eraser housed therein, and its writing tip protrudes from a tip hole at the tip barrel. In this state, when the cylindrical cam 5 is moved with barrel by knocking a back end of a top crown 37, the movement is transmitted to the sliding piece 6, a proceeding pipe 23, and the mechanical pencil writing body 7, so that the lead is projected. When the top crown 37 is rotated right and left with respect to the front of the back barrel 4, an eraser holder 42 moves back and forth, so that an eraser 47 comes up and down from a back end hole 39.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple writing instrument in which the tips of a plurality of writing bodies can be alternately retracted and retracted at the front end of the front shaft, and an eraser can be retracted and retracted from the rear end of the rear shaft.

[0002]

2. Description of the Related Art As a conventional example, as shown in Japanese Utility Model Laid-Open No. 60-120889 by the same applicant, a writing tip portion of a writing instrument such as a mechanical pencil writing instrument and a ballpoint pen can be selectively projected and retracted, and a cap is provided. There is a double-sided writing instrument in which an eraser appears and disappears by rotating a crown protruding from the rear end.

The conventional pencil lead can be roughly classified into the following four types of production methods, but when used as a colored sharp lead, all have drawbacks. That is,

(1) A baked pencil lead obtained by using graphite as a coloring agent, an organic material as a binder, a clay, etc. as main materials, kneading, molding and baking them. The pencil lead obtained by this method has reached a sufficient practical strength even in a mechanical pencil lead, and is known as a pencil lead which can be erased with an eraser. However, due to the color of the graphite used and the calcined carbon material, pencil leads other than black have the drawback that they cannot be manufactured.

(2) A non-fired pencil lead obtained by kneading and molding waxes, binders, extenders, pigments and the like. According to this production method, various kinds of organic pigments can be used, light resistance and weather resistance are excellent, and a colored pencil lead having a bright hue can be obtained. However, since this colored pencil lead is not fired and mainly depends on the binding with an organic binder, sufficient strength cannot be obtained when it is used as a lead for a mechanical pencil, and because it contains waxes, it is erased with an eraser. There is a drawback that cannot be done.

(3) Water- and oil-repellent substance, binder, extender,
A non-baking pencil lead obtained by kneading and molding a pigment and the like, and further impregnating open pores formed around the water- and oil-repellent substance with oils and fats.
According to this manufacturing method, when an oil or the like that is liquid at room temperature is selected as the oil or fat to be impregnated, it is possible to manufacture 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 to make a colored pencil lead of a vivid hue, since a binder that can be used is limited to an organic polymer substance or the like due to the heat resistance of the pigment, a fine lead for a mechanical pencil or the like is used. In this case, there is a drawback that sufficient strength cannot be obtained.

(4) A pencil lead obtained by further impregnating a dye ink into a light-colored or white-fired porous pencil lead obtained by kneading, molding and firing boron nitride, clay, an organic substance and the like.
The line drawn by the pencil lead obtained by this method can be erased with an eraser. However, since clay is used as a binder, it cannot be said that the strength is sufficient as compared with the core of the above (1), and a pigment that can be used as a pencil core with a bright hue and high heat resistance temperature and is harmless to the human body. Since it does not exist, a dye that can be impregnated after firing is used as the colorant, and there is a drawback that the light resistance and weather resistance are greatly inferior when compared with the pigment cores of the above (2) and (3). Although it is possible to impregnate the pigment-dispersed ink with a core having large pores, it has a drawback that it cannot be used for a pencil lead for a mechanical pencil because the strength is further lowered.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a cylindrical cam is rotated back and forth with respect to a front shaft or a center shaft to alternately move back and forth,
While maintaining the strength as a burning pencil lead in a compound writing instrument capable of selectively projecting and retracting the tip of each writing body from the tip opening of the tip shaft, it has excellent light resistance, weather resistance, and vivid color,
In addition, at least one of the above cursives has a colored sharp core other than black built therein by using the colored sharp lead for mechanical pencils obtained based on the method for producing a baked pencil lead that can be easily erased with an eraser. In addition to the mechanical pencil writing body, a rear shaft is integrally provided behind the cylindrical cam, and an eraser holder having an eraser sandwiched in the rear shaft is provided so as to be movable back and forth. The purpose is to provide a convenient double-sided writing instrument in which an eraser can appear and disappear from the rear end.

Further, the problem of the colored sharp lead used in the multiple writing instrument of the present invention is to solve the above-mentioned drawbacks of the conventional lead, which has markedly excellent mechanical strength and produces vivid colors. Therefore, it is possible to provide a colored sharp core having properties such as drawing a line excellent in light resistance and weather resistance and having erasability by an eraser.

[0010]

MEANS FOR SOLVING THE PROBLEMS An engaging portion for fitting a resin-made front shaft and a resin-made middle shaft in a non-rotatable and retaining manner to each other is provided, and both are fixed and integrated with the center shaft. The cursive body is fitted into the guide grooves of the guide part between the guide part and the sliding piece so that it can be moved back and forth by urging the return springs. A cylindrical cam provided in a circumferential shape is rotatably prevented from moving with respect to the guide part or the center shaft, and each sliding piece is brought into contact with the inclined surface of the cam to alternately move back and forth by the rotation of the cylinder cam with respect to the leading shaft or the center shaft. The tip of each cursive body can be selectively retracted from the tip opening of the tip shaft, and when at least the mechanical pencil cursive body is projected, the cylindrical cam shifts axially with respect to the center shaft and the guide part to allow the core to be extended. And at least one of the above cursive Shall in mechanical pencil cursive colored sharp core other than black is incorporated, the colored sharp core readily erased with an eraser,

As (1), a rear shaft made of resin is integrally provided at the rear of the cylindrical cam, a spiral groove is formed in the inner hole of the rear shaft, and the resin crown has a long slit. The inner cylinder part and the outer cylinder part are integrally formed, the inner cylinder part of the crown is fitted in the inner hole of the rear shaft, and the outer cylinder part is fixed to the outer peripheral part behind the rear shaft so as to be rotatable only. In the inner cylinder part, the elastic part for sandwiching the eraser in the rear and the eraser holder having the protrusion on the front cylinder part are mounted with the protrusions fitted in the slits and the spiral groove, and are attached to the front shaft or the center shaft. By rotating the rear shaft, the tip of the cursive body appears and disappears, and by rotating the outer cylinder part of the crown with respect to the rear shaft, the eraser can appear and disappear.

As (2), a slit is provided in a cylindrical portion extending to the rear of the cylindrical cam to form a rear shaft made of resin, and protrusions and grooves are alternately provided on both sides of the slit of the cylindrical portion. An eraser holder with an eraser attached to the rear is attached by inserting the protrusion provided on the outer periphery of the eraser holder into the groove of the slit in a disengageable manner, and the eraser holder is moved back and forth with respect to the rear shaft to remove the eraser from the rear shaft. It is configured so that it can appear and disappear from the edge.

As (3), the chuck body is integrally formed with the eraser accommodating portion at the rear of the cam portion, and the chuck body is urged rearward with the rear shaft being stopped outside the chuck body. The chuck body is configured to hold the eraser.

The following means can be considered as a method for producing the colored sharp core used in the present invention.

(A-1) A compounded composition containing at least a body material and an organic molding material is kneaded, extruded, and fired in a non-oxidizing atmosphere to obtain a carbonized product of the organic molding material. Forming a first firing core as a binder,
A second fired body comprising at least a body material obtained by heating the first fired core in an oxidizing atmosphere to oxidize and remove a binder of a carbide;
A fired core was formed, and a perhydropolysilazane-containing liquid was impregnated into the pores of the second fired core, and silicon nitride was generated by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. A high-strength fired pencil lead in which a third fired core having open pores is formed, and the third fired core is colored with a coloring agent. (A-2) A fired pencil lead containing a dye or pigment having excellent light resistance and weather resistance in the open pores of a high-strength fired pencil lead having open pores as at least a colorant. The above "in an inert atmosphere such as a nitrogen atmosphere" means an atmosphere of an inert gas such as a nitrogen gas atmosphere or an argon gas atmosphere.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIGS. 1 to 4 show a first embodiment of the present invention corresponding to the means (1) for solving the above problems. The compound writing instrument of the present invention includes a center shaft 1 integrally provided with a guide portion 2, a front shaft 3, a rear shaft 4 integrally provided with a cylindrical cam 5, a pair of sliding pieces 6, 6 ', and a mechanical pencil writing body 7, 8. , Crown 37, eraser holder 42, eraser 4
7 is the main component. First, the center shaft 1 is made of resin and, as shown in FIG. 1, has a guide groove 9 that is long in the axial direction and opens on the side surface from the substantially central portion to the rear end, and a similar guide groove 9'on the side surface opposite to it. A guide unit 2 is provided. The front half of the guide portion 2 communicates with each of the guide grooves 9 and 9'and has a hole 32,
A tubular portion 10 having a partition portion 16 having a length of 32 "and an opening at the front end is provided, and a step portion 31 is provided at the rear end of the tubular portion 10, and a bulging engagement is provided on the front outer peripheral portion of the step portion 31. A joint portion 13 is formed.

Further, as shown in FIG. 2, a vertical groove 18 is formed on the rear side surface of the center shaft 1 with a narrow portion 18b via a forward inclined surface 18a.
Is connected to the circumferential groove 19 to form a substantially gate-shaped window portion. Further, as will be described later, the protrusion 17 of the cylindrical cam 5 is provided with the vertical groove 18
Then, the protrusion 17 elastically expands the inclined surface 18a, passes through the narrow portion 51, and enters the circumferential groove 19. The cylindrical cam 5 rotates while the projection 17 contacts the circumferential rear wall of the circumferential groove 19 so that the writing portion of the mechanical pencil writing body 7 or the mechanical pencil writing body 8 appears and disappears alternately from the tip end opening of the tip shaft. Become. Further, the circumferential groove 19 is a mechanical pencil cursive body 7.
And the projection 1 when the mechanical pencil cursive body 8 projects
Wide groove 50 so that the cylindrical cam 5 can move axially at position 7
a and 50c are provided, and a narrow groove 50b is provided between the rear wall 48 and the front wall of the circumferential groove 19 so that the cylindrical cam 5 cannot substantially move axially at the position of the protrusion 17 when the cursive body is stored. A front wall 49b protruding rearward is provided so as to be formed.

The front end of the tip shaft 3 is tapered, and the tip end of the inner hole portion is provided with an inner step portion 27. In the rear end hole, an engagement groove 12 is provided, which engages with an engagement portion 13 provided on the outer peripheral portion of the cylindrical portion 10 of the guide cylinder, and prevents the cylindrical portion 10 from slipping out and rotating. . The cylindrical portion 10 and the front shaft 3 are detachably fixed by an appropriate force. (Showa 6
(Same as the configuration of the front shaft in JP-A-4-3491)

The rear shaft 4 is made of resin and has a cylindrical cam 5 integrally at its tip. The cylindrical cam 5 has a cylindrical shape, and has a cam slope 14 that is circumferentially displaced back and forth at the front end edge.
A cutout 15 is formed at the foremost end of the fourth member 4. Further, on the side surface of the cylindrical cam 5, there is formed a protrusion 17 which is inserted into the vertical groove 18 of the center shaft 1 and elastically fits into the circumferential groove 19 so as to rotate and prevent from coming off within a certain range (approximately 180 degrees). .

By the way, the rear shaft 4 has a cylindrical portion extending behind the cylindrical cam 5, and a spiral groove 33 is formed in the inner hole of the cylindrical portion. A rear end of the cylindrical cam 5 has a boss portion 36 which protrudes slightly in a circumferential shape, and a shaft portion 34 having a protruding engagement portion 35 is provided at the rear of the cylindrical portion. On the other hand, the crown 37 made of resin is an inner cylindrical portion 40 having a long slit 41.
b and an outer cylindrical portion 40a formed with an engaging portion 38 having a circumferential groove on the inner surface on the outside thereof. In the crown 37, the inner tubular portion 40b is fitted in the inner hole of the rear shaft 4, and the engaging portion 38 of the outer tubular portion 40a is elastically fitted in the engaging portion 35 so that the crown 37 is the outer tubular portion. At 40a, it is fixed to the cap 4 so as to be rotatable only. The boss portion 36 serves as a guide for the tip of the inner tubular portion 40b.

Further, an eraser 4 is provided at the rear end in the inner tubular portion 40b.
7 is attached. The eraser holder 42 is formed with a pair of elastic pieces 45 for sandwiching the eraser 47 at the rear, and has an engaging projection 46 on the inner surface of the elastic piece 45. A projection 44 is formed on the outer periphery of the front cylindrical portion 43. The eraser holder 42 has the projection 44 and the elastic piece 45 fitted in the slit 41 of the inner cylinder, and the projection 44 is further fitted in the spiral groove 33 so that the inner cylinder 40 b
It is arranged inside. In this state, when the outer cylindrical portion 40 a is rotated with respect to the rear shaft 4, the eraser holder 42 moves back and forth, so that the eraser 47 can protrude and retract from the rear end hole 39.

Further, the sliding piece 6 has a projection 22 on the outer surface thereof, and a central portion projects from the rear end surface of the projection 22 and both sides thereof have substantially the same slope as the cam slope 14 of the cylindrical cam 5 described above. It has a slope. Further, a hole is provided which abuts against the flange portion 24 of the core pipe 23 to protrude and fit the rear of the core pipe 23 long. Further, the sliding piece 6 ', like the sliding piece 6, has a projection 22' and a cam slope. Mechanical pencil writing bodies 7 and 8 are fitted to the tips of core pipes 23 and 26 penetrating the sliding pieces 6 and 6 '.

The mechanical pencil writing body 7 incorporates a general chuck mechanism, is joined to the core pipe 23 via a joint 29 connected to the chuck mechanism at the rear end, and has a flange portion 24 provided behind the core pipe 23. The sliding piece 6 is fitted in contact with the sliding piece 6, and the rear end hole of the core pipe 23 protruding from the rear end of the sliding piece 6 is closed by a tail plug 25 or the like. The leading of the lead is performed by moving the chuck by the axial movement of the sliding piece 6 in a state where the step 28 at the tip end of the mechanical pencil 7 is in contact with the inner step 27 of the front shaft 3. Incidentally, the mechanical pencil cursive body 8 is also made in the same manner.

Next, the assembly order will be described. The mechanical pencil writing bodies 7 and 8 are connected to the respective sliding pieces 6 and 6'in the rearward direction to form the guide grooves 9 and 9 of the guide portion 2 of the center shaft.
It is movably fitted to the rear side and is urged rearward by the return springs 30 and 30 'interposed between the front end surfaces of the sliding pieces 6 and 6'and the guide grooves 9 and 9' To be done. In the rear shaft 4, the cylindrical cam 5 is inserted into the rear end hole of the center shaft 1 and the protrusion 17 is elastically fitted in the circumferential groove 19, so that the center shaft 1 is rotatable about 180 degrees in the circumferential direction and is prevented from coming off. Then it is fastened. Further, the rear shaft 4 is capable of shifting the stroke by the stroke required for centering with respect to the center shaft 1 in a state where the mechanical pencil writing bodies 7 and 8 are projected, and the stylus cannot be moved when the writing body is stored. Further, since the sliding pieces 6, 6'are always urged rearward by the return springs 30, 30 ', the cam slopes of the projections 22, 22' are always in contact with the cam slope 14 of the cylindrical cam 5. Is kept.

Also, with the rear end surface of the front shaft 3 in contact with the front surface of the stepped portion 31 of the center shaft 1, the engagement portion 13 of the tubular portion 10 is elastically fitted in the engagement groove 12 of the front shaft 3. As a result, the front shaft 3 and the center shaft 1 are fixed in a rotation-stopping and slip-out preventing state. The tip shaft 3 is detachable with an appropriate force. In this state, when the rear shaft 4 is rotated to one side with respect to the front shaft 3 or the center shaft 1, the sliding piece 6 moves forward and the notch 15 at the foremost end of the cam slope 14 of the cylindrical cam has one mechanical pencil writing body 7. Projection 2 of sliding piece 6
2 and the writing tip is projected from the tip end opening of the tip shaft. Further, when the rear shaft 4 is rotated to the other side with respect to the front shaft 3 or the center shaft 1, the sliding piece 6 retracts and the writing tip portion of the mechanical pencil writing body 7 is retracted from the tip end opening of the leading shaft. The 6 ”advances and the writing tip of the other mechanical pencil writing body 8 projects from the tip shaft opening.

On the other hand, the eraser holder 42 to which the eraser 47 is attached is inserted from the rear end of the cap 4 with the eraser holder 42 fitted in the inner cylinder portion 40b of the crown 37 while rotating, and the outer cylinder portion of the crown is inserted. 40a is fixed to the rear end of the cap 4. As described above, when the outer cylinder portion 40a of the crown is rotated to the left or right with respect to the rear shaft 4, the eraser 47 appears and disappears from the rear end hole 39.

FIGS. 3 and 4 show another corresponding example showing the engagement state between the protrusion 17 of the cylindrical cam and the center shaft 1 '. In this case, as means for fitting the projection 17 into the circumferential groove 60,
A partition wall 62 having an inclined surface 63 is provided on an upper wall of a guide groove 61 in which the projection 17 is fitted from the rear end of the central shaft 1 #.
The reason for providing the partition wall 62 is to enhance the rigidity of the center shaft 1 ° at the engaging portion.

By the way, although two mechanical pencil writing materials are provided in the embodiment, three or more mechanical writing materials may be provided. In that case, it is possible to use one of them as a writing material such as a ballpoint pen. Further, there are various means for fixing the cylindrical cam to the center shaft so as to prevent it from coming off and to be rotatable, which are not limited to the above-mentioned embodiment. Further, although the guide portion of the sliding piece is formed integrally with the center shaft, a separate guide portion can be fixed. Further, although the rear end of the core pipe is projected to the rear of the sliding piece through the sliding piece, it is also possible to provide the rear portion of the sliding piece so as to project long.

FIG. 5 shows a second embodiment of the present invention corresponding to the above means (2) for solving the problems.
The multiple writing instrument of this embodiment has the same components as those of the above-mentioned embodiment, and only the differences will be described below. The rear shaft 70 is made of resin,
A cylindrical cam 71 is integrally provided at the tip. Cylindrical cam 71
Has a cylindrical shape, and has a cam slant surface that is displaced circumferentially back and forth at the front end edge, and a notch is formed at the foremost end of the cam slant surface. Further, the rear shaft 4 has a cylindrical portion 72 extending rearward of the cylindrical cam 71, a slit 73 is bored on the side surface of the cylindrical portion 72, and projections 74 and grooves 75 are alternately formed on both sides of the slit 73. It is provided in.

Further, an eraser holder 79 having an eraser 84 fixed to the rear end is mounted in the tubular portion by engaging an engaging projection 82 provided on the outer periphery thereof in a groove 75 of the slit 73 so as to be detachable. . The engaging projection 82 is formed at the tip of an elastic piece 80 provided on the side surface of the eraser holder 79, and is engaged with the eraser 84 while elastically displacing in the groove 75 as it slides.
Hold the protruding state of. Further, the eraser holder 79 can be moved while slightly projecting the center of the engaging protrusion 82 to form the operating protrusion 81, and moving the operating protrusion 81 forward and backward to release the engagement between the engaging protrusion 82 and the groove 75. And A crown 77 is fixed to the rear end of the cylindrical portion. Incidentally, if necessary, the rear end portion 76 of the cylindrical portion and the contact portion 78 of the crown 77 are formed in a slanted shape to be substantially in contact with each other, so that the rear end of the slit 73 is prevented from being deformed.

On the other hand, the assembly order will be described.
Insert the eraser holder 79 from the rear end of the 0 cylinder,
The engagement protrusion 82 of the eraser holder 79 is engaged with the groove 75 of the slit 73 provided in the tubular portion to erase the eraser holder 79.
Is slidable with respect to the tubular portion. Further, the crown 77 is fixed to the rear end of the cylindrical portion, and the eraser 84 is inserted from the opening at the rear end of the crown 77, and the rear end of the eraser 84 is fixed to the eraser holder 79. As described above, when the eraser holder 79 is moved back and forth, the eraser 84 appears and disappears from the opening of the crown 77. The inner diameter of the opening of the crown 77 is slightly larger than the outer diameter of the eraser 84.

FIG. 6 shows a third embodiment of the present invention corresponding to the above means (3) for solving the problems.
The writing instrument of the embodiment also has a common part similar to the previous example,
Hereinafter, only the differences will be described. The cam portion 100 has a tubular shape,
The front end edge has a cam slope that is circumferentially displaced forward and backward, and a notch is formed at the foremost end of the cam slope. Further, a flange portion 102 is formed behind the cam portion 100, and a chuck body 101 is integrally formed behind the cam portion 100.
(It may be a separate member for convenience.) Further, the outer peripheral portion at the rear of the chuck body 101 has an appropriate slit (not shown) to form a diameter-reducible gripping portion. Further, the inner step portion 103 is provided at the rear end of the inner hole of the chuck body 101.
Are formed.

Further, the rear shaft 90 has a projecting locking portion 95 on the outer periphery of a shaft portion 94 at the rear end, and a projecting portion 92 in a substantially intermediate inner hole. In addition, before and after the projecting portion 92, the inner hole has inner peripheral portions 91, 93 having a polygonal cross section as appropriate. By the way, the outer periphery of the collar portion 102 behind the cam portion 100 has the same polygonal shape fitted in the polygonal hole. The spring 105 is fitted from the rear end of the chuck body 101, and the front end of the spring 105 is brought into contact with the rear end of the collar portion 102. From this state, the rear shaft 90 is fitted into the chuck body 101, the rear end of the spring 105 is brought into contact with the rear end inner step of the shaft portion 94, and the collar portion 102 elastically moves the rear shaft protrusion 92. It gets over and engages and is prevented from coming off. Further, the collar portion 102 is prevented from rotating by the above-mentioned polygonal fitting, and the spring 105
Then, the rear shaft 90 is biased against the chuck body 101 so that the rear shaft 90 can move.

A fastener 104 is fitted on the outer periphery of the grip portion at the rear end of the chuck body 101, and is further fitted to fix a crown 96 to the shaft portion 94 of the rear shaft. In addition, a groove-shaped locking portion 99 that engages with the locking portion 95 of the shaft portion is provided in the front opening of the crown 96.
Is provided. Also, the crown 9 to which the fastener 104 is fitted.
A step portion 98 is provided at the rear end of the inner hole of 6, and a hole portion 97 that appropriately frictionally engages with the eraser 106 is provided at the rear end.

Next, the assembly order will be described. A spring 105 is fitted on the outer peripheral portion of the chuck body 101, the cam portion 100 is fitted in the inner hole of the rear shaft 90, and the collar portion 102 is formed on the protrusion 9.
2 is engaged with the cam portion 100 and the chuck body 1 with respect to the rear shaft.
01 is prevented from coming off and rotation is stopped. Next, the fastener 104 is fitted into the outer periphery of the grip portion of the chuck body, and the crown 96 is fixed to the shaft portion 94 at the rear end of the rear shaft. Next, the chuck body 1
The eraser 106 is inserted in a state where the rear shaft 90 is advanced with respect to 01 and the grip portion of the chuck body is expanded.

As a method for producing the colored sharp core used in the multiple writing instrument of the present invention, a perhydropolysilazane-containing liquid is impregnated into the pores of a specific calcined porous core made of at least a body material, a nitrogen atmosphere, etc. It has been found that this can be solved by forming silicon nitride as a binder by heat treatment in an inert atmosphere or an ammonia gas atmosphere.

That is, the colored sharp core is carbonized by kneading, extruding, and firing in a non-oxidizing atmosphere a compounding composition containing at least an extender and an organic excipient. The first with carbonized carbide as binder
Forming a fired core, and heating the first fired core in an oxidizing atmosphere to oxidize and remove the binder of the carbide to form a second fired core made of at least an extender; Impregnated with perhydropolysilazane-containing liquid in the pores,
A third fired core body in which silicon nitride is generated by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere is formed, and the third fired core body is formed with a coloring agent excellent in light resistance and weather resistance. It is a colored high strength fired sharp core. or,
A high-strength fired sharp core obtained by filling a colorant having excellent light resistance and weather resistance in the pores of the third fired core.

The high-strength fired colored sharp core used in the present invention will be described in detail below. First, the first firing core is made of a raw material of a blended composition containing at least a body material and an organic shaping material.

The extender is not particularly limited as long as it has been conventionally used in a fired color pencil, and any one can be used. For example, white-based materials such as titanium oxide, mica, talc, boron nitride, silica, alumina, and calcium carbonate, and colored materials such as molybdenum disulfide and tungsten disulfide can be used depending on the hue. Of course, mixtures of these several types can also be used. Moreover, you may mix | blend a heat resistant pigment as needed.

Examples of the organic shaping material include thermoplastic resins such as vinyl chloride resin, chlorinated vinyl chloride resin and polyvinyl alcohol, thermosetting resins such as furan resin, phenol resin and epoxy resin, lignin, Natural polymer substances such as cellulose and tragacanth gum, petroleum asphalt, coal tar pitch, naphtha decomposition pitch,
Any of pitches such as dry-distilled pitch such as synthetic resin can be used, and naturally, a mixture of these several kinds can also be used.

Further, water, dioctyl phthalate (DOP), dibutyl phthalate (DB) are used for the purpose of improving the characteristics of kneading and extrusion molding which are performed by applying a high shearing force.
P), tricresyl phosphate (TCP), dioctyl adipate (DOA), propylene carbonate, alcohols, ketones, esters and the like, one or more kinds of plasticizers or solvents for organic excipients are required. You may mix | blend according to it.

After thoroughly kneading these blended compositions with a Henschel mixer, pressure kneader, two rolls, etc., they are extruded into fine wires by an extruder, and then in an atmosphere of nitrogen or inert gas such as argon gas. By firing in a non-oxidizing atmosphere such as a gas atmosphere, a first fired core body using a carbide obtained by carbonizing an organic shaping material as a binder is obtained. The obtained first fired core body is a core body in which the pores generated by firing and the binder of the carbide are finely and sufficiently present and uniformly dispersed, and the extender is highly oriented.

In order to increase the strength of the second fired core and to improve the handleability, clay, such as bentonite or kaolin, may be added to the compounded composition to obtain the first fired core, if necessary. A binder may be blended, and if the blending amount is suppressed to less than 25% by weight, the strength due to silicon nitride described later is likely to be exhibited. Further, if necessary, the first fired core obtained above was impregnated with a liquid containing perhydropolysilazane, and silicon nitride was produced by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. It may be a fired core.

The first calcined core obtained above is heated in an oxidizing atmosphere to oxidize and remove the binder of the carbide, whereby a second calcined core composed of a porous core having a large number of pores is obtained. . Here, the porosity of the second firing core is obtained by removing a porosity obtained by firing a kneaded material composed of an extender and an organic shaping material in a non-oxidizing atmosphere, and the binder of the carbide. It is composed of both of the pores obtained by. The porosity of the second fired core is adjusted mainly by adjusting the mixing ratio of the organic shaping material, but in addition to this, a pore-forming material such as a carbon particulate material may be appropriately added. I don't care. The amount of pores due to the removal of the binder of the carbide with respect to all the pores is completely arbitrary.

As described above, the obtained second fired core is a porous core having a large number of pores, and the pores are fine and sufficiently present and uniformly dispersed. It is a core in which the material is highly oriented. As a result, the second fired core obtained from the first fired core becomes useful for obtaining the desired high strength fired colored sharp core.

The third calcined core body is obtained by impregnating the second calcined core body made of the porous core body obtained above with a perhydropolysilazane-containing liquid, and then impregnating the perhydropolysilazane-containing liquid with the second calcined core body. 2 Obtained by heat-treating the fired core at 400 ° C. or higher, preferably 600 ° C. or higher in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere to generate silicon nitride as a binder in the second fired core. .

The larger the filling amount of the perhydropolysilazane-containing liquid in the second fired core, that is, the higher the porosity of the second fired core, the greater the amount of silicon nitride produced as the binder, and the better. The mechanical strength of the third fired core obtained is high. However, if the porosity of the second fired core exceeds 80%, the shape of the core is difficult to maintain, and the impregnation step of the perhydropolysilazane-containing liquid becomes difficult. Further, when the porosity is less than 30%, the filling amount of the perhydropolysilazane-containing liquid is small, and the mechanical strength cannot be remarkably improved,
Further, if the porosity is less than 30%, the amount of the ink filled in the obtained third baked core is small, and practical color development and density cannot be obtained, which is not preferable. Therefore, the range of the porosity of the second fired core is, for example, 30 to 80%, but in order to improve the quality of the obtained third fired core, the porosity is set to 35 to 75%. preferable.

Further, the perhydropolysilazane used for obtaining the third fired core is a ceramic precursor polymer, has a [-Si-N-] structure in the main chain, and has only hydrogen bonded to the side chain. In the general formula, [SiH _a N
_b ] _n (wherein _a is 1 to 3 and _b is 0 or 1),
A structure mainly having a skeleton of [-SiH ₂ NH-] _n is shown. Further, only hydrogen is eliminated by thermal decomposition in an inert atmosphere such as a nitrogen atmosphere or in an ammonia gas atmosphere, and silicon nitride as a binder can be obtained in a very high yield. Most of the generated silicon nitride is trisilicon tetranitride [Si ₃ N ₄ ], but it may exist in a slightly different form [Si _x N _y ] depending on the raw material used, heat treatment conditions, and the like.

Further, since it does not contain an organic component such as a methyl group, a colorless and transparent, high-purity silicon nitride containing no carbon can be obtained. Furthermore, the temperature at which the obtained silicon nitride is lower than other sintering methods, that is, the sintering method obtained from silicon powder is 1200 ° C.
Although the treatment was performed at a high temperature of 1400 ° C., this method is characterized in that it can be obtained at a low temperature of about 600 ° C. in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. The perhydropolysilazane-containing liquid used in this method is a solution of the above-mentioned perhydropolysilazane dissolved in an organic solvent, and if the perhydropolysilazane-containing liquid can impregnate the second firing core, an organic solvent to be used Is not particularly limited, and any of them can be used. Examples of the organic solvent used include organic solvents such as benzene, toluene, xylene, tetrahydrofuran (THF), methylene chloride, carbon tetrachloride, and aromatic hydrocarbons.

As a method of impregnating the second calcined core with the perhydropolysilazane-containing liquid, the second calcined core is dipped in the perhydropolysilazane-containing liquid, and if necessary, heated, decompressed, pressurized, or the like. It can be performed by impregnating under. Here, the impregnated state of the perhydropolysilazane-containing liquid is finely and uniformly dispersed and impregnated in the second fired core. That is, in the second fired core, as described above, the pores are fine and sufficiently present, and are uniformly dispersed, the extender is highly oriented, and a high strength fired colored sharp core is obtained. Because it is useful for
The perhydropolysilazane-containing liquid is finely and uniformly dispersed and impregnated in the second fired core. Incidentally, in order to obtain a high-strength third fired core, the impregnation of the perhydropolysilazane-containing liquid and the firing step may be repeated if necessary.

The obtained third fired core body is formed by finely and uniformly dispersing silicon nitride as a binder in the core body. Further, since the extender material is highly oriented, a small amount of nitriding is performed. Due to the formation of silicon, the strength of the core is easily expressed, and the collapse of the core during writing becomes uniform.

The high-strength baked colored sharp core is obtained by filling the pores of the third baked core obtained above with a colorant having excellent light resistance and weather resistance. As a colorant to be filled, a dye excellent in light resistance and weather resistance is water,
It can be dissolved in an organic solvent or the like to form an ink and further impregnated. Further, when light resistance and weather resistance are required, use of a pigment can be considered, but it is not possible to color the inside of the core simply by dispersing water, an organic solvent, etc. , A method of impregnating an organic pigment dissolved in an organic solvent or the like, and further solidifying the pigment in the open pores by means such as water precipitation, or impregnating a liquid containing a pigment precursor into the open pores of the core, and further opening. The pigment can be filled up to the inside of the core by, for example, a method of performing a pigmentation reaction in the pores, a method of impregnating the open pores of the core with a dye solution or a precipitant solution, and performing a lake reaction in the open pores to form a pigment.

In any of the above colorant filling methods, for the purpose of promoting impregnation, it is possible to perform impregnation under heating, reduced pressure or pressure, or in the presence of a surfactant or other additive. Is. Further, it is possible to make the color tone deeper by repeatedly filling, and it is also possible to color by two different filling methods.

Furthermore, it is possible to improve the lubricity during writing by impregnating the extra open pores with oil or the like. In order to be able to erase as much as a burned black lead (black lead) with an eraser, it is necessary to select from oils and fats and / or waxes that are liquid at room temperature. Specifically, silicone oil, mineral oil, liquid paraffin, α-olefin oligomer and the like are used.

[0055]

In the first embodiment, when the rear shaft 4 is rotated to one side with respect to the front shaft 3 or the center shaft 1, the notch provided at the tip of the cam slope 14 of the cylindrical cam 5 as shown in FIG. 15 engages with the sliding piece 6 of one of the mechanical pencil writing bodies 7 to project the writing tip end portion from the tip end opening. At this time, the protrusion 17 of the cylindrical cam 5 is located in the wide groove 50a in the circumferential groove 19 of the center shaft 1. When the rear end of the crown 37 is knocked in this state and the cylindrical cam 5 is axially moved, the operation is transmitted to the sliding piece 6, the core pipe 23, and the mechanical pencil writing body 7, and the step portion 28 of the writing tip portion is moved. The chuck moves axially together with the joint 29 from the state in which the chuck is in contact with the inner step portion 27 of the front shaft 3 and the core is paid out. When the rear shaft 4 is rotated to the other side with respect to the front shaft 3 or the center shaft 1, the mechanical pencil writing body 7 is retracted, and instead, the writing tip portion of the mechanical pencil writing body 8 projects from the leading shaft tip opening. When the cursive is stored, the protrusion 1
7 is located in the narrow groove 50b of the circumferential groove 19 and cannot be knocked. Next, when the crown 37 is rotated left and right with respect to the front of the rear shaft 4, the eraser holder 42 moves back and forth, and the eraser 47 appears and disappears from the rear end hole 39.

In the second embodiment, when the rear shaft 70 is rotated to one side with respect to the front shaft 3 or the center shaft 1, as shown in FIG. 5, the notch provided at the tip of the cam slope of the cylindrical cam 71. Engages with the sliding piece of one of the shap pencil writing bodies 7 to project its writing tip portion from the tip shaft tip opening. When the rear end of crown 77 is knocked in this state and the cylindrical cam is axially pushed, the operation is performed by the sliding piece, core pipe, and mechanical pencil writing body 7.
Is transmitted to the inner step portion 2 of the leading shaft 3
From the state where it abuts on 7, the chuck moves axially together with the joint, and the lead is paid out. Further, when the rear shaft 70 is rotated to the other side with respect to the front shaft 3 or the center shaft 1, the mechanical pencil writing body 7 retracts, and instead, the writing tip portion of the mechanical pencil writing body 8 projects from the leading shaft tip opening.

Next, when the operation projection 81 of the eraser holder 79 is pushed back with respect to the rear shaft 70, the engagement projection 82 is formed.
Moves away from the groove 75 of the slit 73, the eraser holder 79 is gradually retracted, and the eraser 84 is fed out from the opening of the crown 77. Also, the operation protrusion 81
When is pushed forward, the eraser holder 79 moves forward and, at the same time, the eraser 84 sinks from the opening of the crown 77.

In the third embodiment, when the rear shaft 90 is rotated to one side with respect to the front shaft 3 or the center shaft 1, as shown in FIG. 6, a notch provided at the tip of the cam slope of the cam portion 100. Engages with the sliding piece of one of the mechanical pencil writing bodies 7 to project its writing tip portion from the tip shaft tip opening. In this state, if the rear end of the crown 96 is knocked and the cam portion 100 is axially moved, the movement is transmitted to the sliding piece, the core pipe, and the mechanical pencil writing body 7, and the step portion 28 at the writing tip portion is transmitted.
From the state in which the core abuts on the inner step portion 27 of the tip shaft 3, the chuck moves axially together with the joint, and the lead is fed.

When the rear shaft 90 is rotated to the other side with respect to the front shaft 3 or the center shaft 1, the mechanical pencil writing body 7 retracts, and instead, the writing tip of the mechanical pencil writing body 8 projects from the leading shaft tip opening. To do. Next, when a finger is put on the rear end of the base portion 108 of the clip 107 to move the rear shaft 90 forward with respect to the center shaft 1, the rear shaft 90 moves forward with respect to the chuck body 101 from a state in which the cam portion 100 is prevented from moving forward. Eraser 10
6 emerges from the hole 97 of the crown 96. That is, the fastener 1
04 is engaged with the outer periphery of the grip portion of the chuck body 101 and is movable within a range in which it contacts the stepped portion 98 of the crown inner hole. Therefore, the eraser 106 has a pitch substantially equal to the movable range of the fastener 104.
Are fed from the hole 97.

[0060]

Industrial Applicability As described above, the present invention is a compound writing instrument comprising a plurality of writing body tip portions that can be selectively retracted from the front shaft tip opening, and that is provided at the rear end with an eraser that can be retracted. At least one of the cursive bodies is a mechanical pencil cursive body having a colored sharp core other than black, and the colored sharp core is an easily erasable core with an eraser. Sharp core is a fired porous pencil core that solves the above-mentioned drawbacks of conventional cores, keeps the strength strong, and makes it possible to draw a bright color and draw a line excellent in light resistance and weather resistance, and erasability with an eraser It is possible to provide a convenient double-sided writing instrument that has characteristics such as having the property of being easy to write and erase and is equipped with an erasable color core other than black. .

Specifically, it has two mechanical pencil writing bodies, a W pen having a black mechanical lead and a red mechanical pencil respectively, and three mechanical pencil writing bodies,
A triple pen with a black sharp lead, a red sharp lead, a blue sharp lead, etc., a double pen with two writing pencils and a writing pen such as a ballpoint pen, etc. We can provide convenient multiple writing instruments according to your choice. Becomes

[Brief description of the drawings]

FIG. 1 is an overall vertical cross-sectional view showing a first embodiment of the present invention, a part of which is shown in non-cross-section.

FIG. 2 is an explanatory diagram showing an engagement state between a projection of a cylindrical cam and a peripheral groove of a center shaft.

FIG. 3 is an explanatory view showing another example of an engagement state between a projection of a cylindrical cam and a peripheral groove of a center shaft.

FIG. 4 is a cross-sectional view of a main part of an engaging portion in FIG. 3;

FIG. 5 is an overall vertical cross-sectional view showing a second embodiment of the present invention, which is partially shown in non-cross-section.

FIG. 6 is an overall vertical cross-sectional view showing a third embodiment of the present invention, which is partially shown in non-cross-section.

[Explanation of symbols]

 1 Middle shaft 1 `Mid shaft 2 Guide part 3 Leading shaft 4 Rear shaft 5 Cylindrical cam 6 Sliding piece 6` Sliding piece 7 Mechanical pencil writing material 8 Mechanical pencil writing material 9 Guide groove 9` Guide groove 10 Cylindrical part 11 Knock spring 12 Engagement groove 13 Engagement portion 14 Cam slope 15 Notch 16 Partition 17 Protrusion 18 Vertical groove 18a Inclined surface 18b Narrow portion 19 Circumferential groove 20 Wall 21 Window 22 Protrusion 22 "Protrusion 23 Core pipe 24 Flange portion 25 Tail plug 26 Core Pipe 27 Inner step 28 Step 29 Joint 30 Return spring 30 'Return spring 31 Step 32 Hole 32' Hole 32 Spiral groove 34 Shaft section 35 Engagement section 36 Boss section 37 Crown crown 38 Engaging section 39 Rear end hole 40a Outer tube portion 40b Inner tube portion 41 Slit 42 Eraser holder 43 Tube portion 44 Protrusion 45 Elastic piece 46 Locking protrusion 47 Eraser 48 Rear wall 49a Front wall 49b Front wall 49c Front wall 49c Front wall 50a Wide groove 50b Narrow groove 50c Wide groove 60 Circumferential groove 61 Guide groove 62 Partition wall 63 Inclined surface 70 Rear shaft 71 Cylindrical cam 72 Cylindrical part 73 Slit 74 Protrusion 75 Groove 76 Rear end 77 Crown 7 78 Contact portion 79 Eraser holder 80 Elastic piece 81 Operation protrusion 82 Engagement protrusion 83 Fitting portion 84 Eraser 90 Rear shaft 91 Inner peripheral portion 92 Protruding portion 93 Inner peripheral portion 94 Shaft portion 95 Locking part 96 Crown crown 97 Hole part 98 Step part 99 Locking part 100 Cam part 101 Chuck body 102 Collar part 103 Inner step part 104 Fastener 105 Spring 106 Eraser 107 Clip 108 Base part

Claims (5)

[Claims] 1. A compound writing instrument in which the tip of each writing body can be selectively retracted from the tip opening of the tip shaft by alternately moving back and forth by the rotation of a cylindrical cam with respect to the tip shaft or the center shaft.
At least one of the cursive bodies is a mechanical pencil cursive body in which a colored sharp lead other than black is built in, and the colored sharp lead can be easily erased with an eraser. A rear axle is provided,
An eraser holder in which an eraser is sandwiched is provided in the rear shaft so as to be movable back and forth, and the eraser can be retracted from the rear end of the rear shaft. 2. A plurality of guide parts integrated with the center shaft by respectively providing engagement parts for fitting the resin-made front shaft and the resin-made center shaft ahead in a non-rotatable and slip-out preventive state. In each of the guide grooves, a cursive body is fitted between the guide part and the sliding piece by a return spring to be movable back and forth, and a cam slope that is displaced in the axial direction is provided at the front end in a circular shape. The cylindrical cam is locked so that it can rotate with respect to the guide part or center shaft,
By bringing each sliding piece into contact with the sloped surface of the cam, the cylindrical cam is rotated back and forth with respect to the leading shaft or the center shaft to alternately move back and forth, so that the tip of each writing body can be selectively retracted from the tip opening of the leading shaft. The double-sided writing instrument according to claim 1, wherein when the mechanical pencil writing body is projected, the cylindrical cam shifts axially with respect to the center shaft and the guide portion to allow the lead to be drawn out. 3. A rear shaft made of resin is integrally provided behind the cylindrical cam, and a spiral groove is formed in an inner hole portion of the rear shaft,
The resin crown is integrally provided with the inner and outer cylinders with long slits, the inner cylinder of the crown is fitted into the inner hole of the rear axle, and the outer cylinder is rearward of the rear axle. In the state where the protrusion is fitted in the slit and the spiral groove, the elastic part that is rotatably fixed to the outer peripheral part of the inner cylinder part holds the eraser in the rear part and the eraser holder has the protrusion on the front cylinder part. It is mounted so that the tip of the cursive body appears and disappears by rotating the rear shaft with respect to the front shaft or the center shaft, and the eraser can appear and disappear by rotating the outer cylinder part of the crown with respect to the rear shaft. The compound writing instrument according to claim 1 or 2, characterized in that. 4. A cylindrical cam extending rearward from the cylindrical cam is provided with a slit to form a rear shaft made of resin, and a protrusion and a groove are alternately provided on both sides of the slit of the cylindrical cam, and an eraser is provided to the rear. The eraser holder is attached so that the protrusion provided on the outer periphery of the eraser holder is removably fitted into the groove of the slit, and the eraser holder is moved back and forth with respect to the rear shaft to project the eraser from the rear end of the rear shaft. The double-sided writing instrument according to claim 1 or 2, wherein the writing instrument is free. 5. A chuck body is integrally formed with an eraser accommodating portion behind the cam portion, and the chuck is urged rearward against the chuck body with the rear shaft being stopped outside the chuck body. The double-sided writing instrument according to claim 1 or 2, wherein the body is configured to hold an eraser.