JP2000198295A - Double writing instrument - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to provide a convenient double-type writing instrument that is excellent in portability, is easy to write and erase, and has a pencil typeface with a built-in colored sharp core that can be erased with an eraser. . [Constitution] In a double-type writing instrument in which the tip of each writing body can be selectively protruded and retracted from the tip end of a front shaft, one of the writing bodies
A pencil eraser with an eraser, a second pencil with a black sharp core, and at least one other
When the book is a pencil pencil writing body with a built-in colored sharp core other than black, when it is projected from the front end of the front shaft, the eraser or the sharp core can be extended by knocking the writing tool rear end with respect to the front shaft,
The colored sharp core is obtained by impregnating a porous fired core with a dye or pigment ink, and its writing line can be easily erased with an eraser.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which the tips of a plurality of writing bodies are selectively made to be able to protrude and retract at a tip end of a front shaft. The present invention relates to the provision of a double-type writing instrument which is a mechanical pencil writing body having a built-in core, and a mechanical pencil writing body having a built-in colored non-black sharp core that can be easily erased with an eraser at least one other.

[0002]

2. Description of the Related Art Conventionally, a plurality of writing bodies fixed to a plurality of knocking operation units in a shaft are slidable along respective vertical grooves provided in the shaft, and a tip of one writing body is selectively provided. And a double-colored writing pen such as a multicolor ballpoint pen that is engaged by projecting from the shaft tip hole, and each of the projections is disengaged from the other writing body and stored in the shaft by the action of a return spring. Are known.

In addition, a plurality of writing bodies having a front shaft and a front end of a guide cylinder fixed to each other and a sliding piece fixed to a plurality of guide grooves provided in the guide cylinder at a rear end thereof are formed between the guide cylinder and the sliding piece. A return cam is urged between them, each of which is fitted so as to be able to move back and forth in the axial direction, and a cylindrical cam having a cam slope which is displaced in the axial direction is provided so as to be rotatable and axially movable with respect to the guide cylinder. By sliding each sliding piece against the cam slope, the sliding piece is alternately moved back and forth by the rotation of the cylindrical cam so that the tip of each writing body can be selectively protruded and retracted from the tip opening of the front shaft. Compound writing instruments equipped with a mechanical pencil and a ballpoint pen are known.

[0004] Further, a cylindrical body enclosing a plurality of writing bodies and having a hollow from a front end to a rear end of an arbitrary writing body protruding, and enclosing a rear part of the cylindrical body, A knock body that is made movable forward and backward along the front-back direction of the cylindrical body, and is swingably supported at a rear portion of the knock body, and any of the plurality of writing objects is moved forward by the knock body. A mechanical pencil that includes a writing body selection unit that projects from the front end of the cylindrical body, a writing state maintaining unit that maintains a state in which the arbitrary writing body protrudes, and a writing body immersion unit that immerses the protruding writing body; 2. Description of the Related Art A writing instrument equipped with a ballpoint pen is known.

[0005] 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, shaping and kneading the main components of graphite, an organic substance, clay, etc. as a coloring agent, and 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 further impregnating a light-colored or white fired porous pencil lead obtained by kneading, molding and firing boron nitride, clay, and an organic substance 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 a binder, the strength is not sufficient as compared with the core of the above (1). In addition, pigments that are vivid hues, have high heat resistance temperatures, and are harmless to the human body and can be used for pencil cores are available. Since it does not exist, a dye that can be impregnated after firing is used as a colorant, and has a disadvantage that light resistance and weather resistance are significantly inferior to those of the pigment cores of (2) and (3). If a core having large pores is used, it is possible to impregnate the pigment-dispersed ink. However, there is a disadvantage that the strength is further reduced and the core cannot be used as a pencil lead for a mechanical pencil.

[0010]

DISCLOSURE OF THE INVENTION The present invention is directed to a double-type writing instrument in which the tip of each writing body can be selectively protruded and retracted from the tip end of a front shaft while maintaining the strength as a fired pencil lead. By using a colored sharp lead for a mechanical pencil obtained based on a method for producing a fired pencil lead that has light resistance, weather resistance, bright color, and can be easily erased with an eraser, Of these, one is an eraser dispensing body, and at least one is a mechanical pencil writing body with a built-in colored sharp core other than black, making it possible to provide a double-type writing instrument that is easy to write and erase. is there.

Another object of the present invention is to solve the drawbacks of the conventional wick used in the double writing instrument of the present invention, and to provide a vivid color with remarkably excellent mechanical strength. To draw a line with excellent light resistance and weather resistance, and to provide a colored sharp core having characteristics such as erasability by an eraser.

[0012]

A rear shaft is joined to the front shaft so as to be appropriately shifted with respect to the front shaft, and a plurality of writing bodies are accommodated in the shaft, and a knock operating portion connected to the writing body is provided on the rear shaft. A double writing implement that projects into a vertical groove provided at the rear end and slides the knock operation part toward the axial end to selectively lock the writing part by projecting from the front end hole of the front shaft;

A plurality of writing bodies having a sliding shaft fixed to the rear end thereof are fixed between the guide cylinder and the sliding piece in a plurality of guide grooves provided in the guide cylinder with the leading shaft and the leading end of the guide cylinder fixed. Energize the return springs and fit them back and forth in the axial direction,
A cylindrical cam having a cam slope displaced in the axial direction is provided so as to be rotatable and axially movable with respect to the guide cylinder, and each sliding piece is brought into contact with the cam slope so that the above-mentioned sliding is performed by rotation of the cylindrical cam. A double writing implement that alternately moves the frame back and forth so that the tip of each cursive can selectively emerge from the tip end of the tip shaft,

[0014] A cylindrical body enclosing a plurality of writing bodies and having a hollow portion extending from a front end to a rear end of an arbitrary writing body, and a rear part of the cylindrical body being wrapped around the cylindrical body. A knock body that can move forward and backward along the front-rear direction, and is swingably supported at the rear part of the knock body, and any one of the plurality of writing objects can be moved from the front end of the cylindrical body by advancing the knock body. A writing tool selecting unit to be protruded, a writing state maintaining unit for maintaining the protruding state of the arbitrary cursive, and a writing pen having a cursive writing immersion part for immersing the protruding cursive,

[0015] In the above-mentioned double writing implement,
The first is an eraser dispensing body, the second is a pencil pencil writing body with a built-in black sharp core, and at least one other is a non-black colored sharp core obtained by impregnating a porous fired core with a dye or pigment ink. And a pencil pencil with a built-in, and the writing lines can be erased easily with an eraser.

The following means can be considered as a method for producing a colored sharp core used in the double-type writing instrument of the present invention.

(A-1) By kneading, extruding, and firing in a non-oxidizing atmosphere a compounded composition containing at least a body material and an organic excipient, a carbonized product of the organic excipient is obtained. Forming a first fired core body as a binder,
The first fired core is heated in an oxidizing atmosphere to remove a carbide binder by oxidation.
A fired core was formed, the pores of the second fired core were impregnated with a perhydropolysilazane-containing liquid, 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 formed by forming a third fired core having open pores and coloring the third fired core with a coloring agent. (A-2) A fired pencil lead containing, as a colorant, at least 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. Note that the above “in an inert atmosphere such as a nitrogen atmosphere” refers to an inert gas atmosphere such as a nitrogen gas atmosphere or an argon gas atmosphere.

[0018]

1 to 7 show a double-type writing instrument according to a first embodiment of the present invention. 8 to 10 show a second embodiment of the present invention. FIGS. 11 and 12 show a third embodiment of the present invention.

First, in the first embodiment, FIG. 1 is a perspective view showing the appearance of a double-type writing instrument. As shown in FIGS. 2 to 7, a clip 5 is integrally formed on the rear side surface of the rear shaft 1, and further, vertical grooves 2 are drilled at four places to the rear end portion.
A partition 3 is provided inward, and a rear end portion 4 of the rear shaft 1 and a longitudinal groove 2 are provided.
A contact portion 35 is formed with the rear end, and a stopper 8 is formed at the leading end of the partition 3. A plurality of rectangular protrusions 6 are provided at the tip of the rear shaft 1 at a plurality of locations, and a groove-like engagement portion 7 is provided at the inner hole.
Are formed.

On the other hand, four holes 11 are drilled at the rear end 12, a projecting engagement portion 10 is provided at the rear of the outer peripheral portion, and a rectangular groove 13 is provided at a plurality of locations substantially at the center, and is formed at the front. Screw joint 1
4 is inserted from the front end side of the rear shaft 1, the engaging portion 10 is elastically fitted into the engaging portion 7, and the projection 6 is fitted into the groove 13. Is fixed to the joint 9 so as to be axially moved integrally with the joint 9 in the rotational direction and with an appropriate stroke in the axial direction.

The knocking operation portion 20 has a plate-like rear end portion 23 bulging outward at the rear and protrusions 24, 2
5 are formed, and an end portion 22 and a boss-shaped locking portion 21 are formed at the tip. A rear end of a writing body 41 such as a ball-point pen is fastened to the tip of the locking portion 21 and fitted in the vertical groove 2 at one place of the rear shaft 1. The writing body 41 such as a ball-point pen has a hole in the joint 9. 11 and located in the shaft, the return spring 40 is connected to the end 22 of the knock operating portion 20 and the end 1 of the joint 9.
It is energized between the two.

Further, other knock operation units 26, 32, 3
Reference numeral 3 denotes a plate-shaped rear end portion 29 which swells rearward and rearward, and protrusions 30 and 31 are formed at appropriate positions inside, and an end portion 28 and a boss-shaped engaging portion 27 are formed at the front end, respectively. At the end of the stop 27, an eraser feeding body 43, a mechanical pencil writing body 42 for a black core, and a mechanical pencil writing body 4 for a colored core are provided.
4 are fixed to the remaining longitudinal grooves 2 of the rear shaft 1 respectively, and the eraser feeding body 43 and the mechanical pencils 42 and 44 penetrate through the hole 11 of the joint 9 and are inserted into the shaft. , A return spring 47 is also biased between the end 28 of the knock operating portions 26, 32, 33 and the end 12 of the joint 9.

It should be noted that the knock operation units 26 and 32, with respect to the length from the rear end 23 to the end 22 of the knock operation unit 20,
The length from the rear end portion 29 to the end portion 33 is set to be shorter by the stroke of the rear shaft 1 with respect to the joint 9 while the shaft is moving. Further, a joint shaft 14 having a front end hole 48 at the joint portion 14 of the joint 9 and a screw-shaped joint portion 46 at the rear end hole is fixed. The joint between the joint 9 and the front shaft 45 can be formed in a shape not limited to a screw. Further, the mechanical pencil 42 for the black core used in the embodiment has the same structure as the double-type writing instrument which is configured to protrude the pencil, such as a mechanical pencil or a ballpoint pen, from the shaft tip by rotating the cap with respect to the front axis. The description of the structure is omitted because it has. Further, the eraser feeding body 43 and the colored pencil mechanical pencil writing body 44 are provided with a shaft-shaped eraser 50 and the colored core 4 at the tip of the same mechanical pencil writing body core feeding device.
9 is arranged so as to be fed out by knocking.
Of course, the mechanical pencil writing body 44 may have the same configuration as the mechanical pencil writing body 42.

Next, a second embodiment will be described with reference to the drawings. This double-type writing instrument has a guide cylinder 55, a front shaft 56, a cylindrical cam 57, a rear shaft 58, a pair of sliding pieces 59, 59 °, a pair of mechanical pencil writing bodies 60, and an eraser feeding body 61 as main components. . First, the guide cylinder 55 has a pair of axially long guide grooves 63, 63 ｀ which are respectively opened on both sides on substantially opposite sides from a substantially central portion to a slightly forward position of a rear end, and a rear end is formed in a front half portion. The front end has an open cylindrical portion 64 communicating with each of the guide grooves 63, 63 °, and the rear end has a circumferential circumferential groove 65 on the side surface portion. The outer surface of the rear end portion has an exposed surface portion 66. The engaging portion 67, which is a circumferential ridge, is provided on the side surface of the front end portion of the guide groove 63, 63 # behind the exposed surface portion 66. A front end of the cylindrical portion 64 is provided with an engagement portion 68 formed of a wedge-shaped axial rib and a groove for dividing the rib, and the entire portion is integrally formed of resin. The parts 67 and 68 are elastically deformable.

Next, the front shaft 56 is formed by an axial groove having a tapered front end and a tapered portion provided at the entrance edge of the front end and the rear end. It has a portion 69, the whole of which is integrally formed of resin, and the engaging portion 69 is elastically deformable. The above-described guide tube 55 is inserted into the inside of the front shaft 56 from the rear end opening thereof, and the engaging portion 68 is locked and fixed to the engaging portion 69 of the front shaft 56.
That is, the ribs of the guide cylinder 55 are fitted into the grooves of the front shaft 56 to prevent rotation in the circumferential direction.
The rib of No. 6 engages with the groove of the guide cylinder 55 to prevent it from falling off. When the rib of the guide cylinder 55 is fitted into the groove of the front shaft 56, even if there is a slight deviation in the circumferential direction, the rib is guided by the tapered portion at the edge of the groove entrance and the wedge-shaped tip shape of the rib. Therefore, both are securely fitted.

The cylindrical cam 57 has a cam slope 70 displaced circumferentially back and forth at the front end edge, a notch at the foremost end of the cam slope 70, and detent ribs on both sides opposite to heat. With a hole at the rear end, and 4 at the approximate center of the inner surface.
The flange 71 is provided on the semicircular portion. The rear shaft 58 has an engaging portion 72 which is a circumferential groove on the front end inner surface, has a groove on the opposing inner surface near the rear end, and has a clip mounting portion 73 on the rear end outer surface. Then, the whole is integrally formed of resin, and the engaging portion 72 is elastically deformable.

The above-described cylindrical cam 57 is inserted into the rear shaft 58, and its rotation preventing rib is fitted into the groove so that rotation in the circumferential direction is impossible. From the rear end of the rear shaft 58. A stopper 75 holding a large-diameter color core 74 is fitted in the hole at the rear end of the cylindrical cam 57, and a knock cover 77 having a stepped portion 76 on the outer surface on the outer periphery of the rear end, and a knock cover decoration 78 Is fitted. A clip 79 is fixed to the clip mounting portion 73 of the rear shaft 58.

The sliding pieces 59, 59 'have a projection on the outer surface, a central portion protruding from the rear end surface of the projection, and both sides thereof have a cam slope having substantially the same gradient as the cam slope 70 of the cylindrical cam 57 described above. have. The mechanical pencil 60 and the eraser feeder 61 have a built-in general chuck mechanism (not shown), and a joint 8 connected to the chuck mechanism at the rear end.
The core pipe 81 and the connecting shaft 81 # are joined via the 0 and 80 #, and the rear ends of the core pipe 81 and the connecting shaft 81 # are
9, 59 °, the core pipe 81, the connection shaft 81
The core or eraser is fed out according to the axis shift of ｀.

The mechanical pencil 60 and the eraser feeder 61 have their sliding pieces 59, 59 'movably fitted in the respective guide grooves 63, 63' of the guide tube 55, and each sliding piece 59, 59 '. , 59 ° and return springs 82, 82 ° interposed between the front walls of the guide grooves 63, 63 ° of the guide cylinder 55. The rear shaft 58 to which the cylindrical cam 57 is attached is engaged with the engaging portion 72 of the inner surface of the front end of the rear shaft 58 by the elastic deformation of the engaging portion 67 of the guide cylinder 55 and is rotatably joined in the circumferential direction. The front end of the cylindrical cam 57 is disposed so as to cover the outer peripheral portion of the rear end of the guide cylinder 55. The sliding pieces 59 and 59 # of the mechanical pencil 60 and the eraser feeding body 61 are returned by return springs 82 and 82 #. Because it is urged backward,
The cam slope of the projection is always the cam slope 70 of the cylindrical cam 57.
Keep in contact with.

The flange 71 on the inner surface of the cylindrical cam 57 is
The guide cylinder 55 is fitted into the circumferential groove 65. The circumferential groove 65 is provided over a range of approximately 180 ° in the circumferential direction, has a wide portion at both ends and a narrow portion at an intermediate portion thereof, and the front wall of the narrow portion is larger than the front wall of the wide portion. It is located ahead of the required distance. The width of the wide portion, that is, the distance between the front wall and the back wall is set to be slightly longer than the sum of the thickness of the pencil 71 and the knock stroke for feeding out the core or eraser of the eraser feeding body 61 and the flange 71. ing. In addition, the distance between the front wall and the rear wall of the narrow portion is a collar 7.
It is set slightly longer than 1.

The flange 71 of the cylindrical cam 57 has the notch at the foremost end of the cam slope 70 of the cylindrical cam engaged with the rear end protruding portion of the projection of the sliding piece 59 of the mechanical pencil 60 on one side. Occasionally, it is positioned corresponding to the wide portion at one end of the circumferential groove 65, and the notch at the front end of the cam slope 70 of the cylindrical cam engages with the rear end protrusion of the cam slope of the sliding piece 59 の of the eraser feeding member 61. When the sliding pieces 59 and 59 ｀ are located at the front and rear intermediate portions of the cam slope 70 of the cylindrical cam 57, the narrow portion is located. It has been adjusted to correspond to the position. still,
The elasticity of the return springs 82 and 82 ° is
The collar 71 is always in contact with the rear wall of the circumferential groove 65 because it acts on the cylindrical cam 57 through 9, 59 °.

The mechanical pencil 60 and the eraser feeder 61 have their sliding pieces 59, 59 'engaged with the notches at the front end of the cam slope 70 of the cylindrical cam, that is, the flange 71 of the cylindrical cam 57 has a guide cylinder. 55 is located at the wide portion of the peripheral groove 65, the front end writing portion 60 ° and the eraser 62 protrude from the front end hole 56 ° of the front shaft, and the sliding pieces 59, 59 ° are located between the front and rear of the cam slope 70. When the collar 71 is located at the narrow portion, the length thereof is appropriately set so that the writing portion 60 ° or the eraser 62 is immersed in the shaft. In the above embodiment, the rotation range of the cylindrical cam 57 with respect to the guide cylinder 55 is approximately 180 °.
The range is free, for example, 240 °
It may be about. This can be expected to reduce the rotation. In that case, the guide groove 6 of the guide cylinder 55
The position of 3, 63 ° also needs to be moved correspondingly.

By the way, as shown in FIGS. 9 and 10,
The eraser dispensing body 61 has a clamping ring 88 engaged with the outer periphery of the distal end of the chuck body 86, and the rear end of the clamping ring 88 abuts on the distal end of the shaft portion 85, and the chuck body 86 is inserted into the shaft portion 85. Further, a joint 80 # biasing a chuck spring 96 between the rear end of the shaft portion 85 and the rear end of the chuck body 86 is fixed so that the front end of the chuck body 86 is always pulled backward. . Further, a chuck body 86 and a tightening ring 88 are fitted to the front end of the shaft portion 85 so as to be able to move back and forth, and a step portion 95 for contacting the front end of the tightening ring 88 and a base 84 having a front end hole 94 at the front end are fixed. Have been.
Further, a guide tube 83 having a holding portion 83 # which is appropriately frictionally engaged with the outer periphery of the eraser 62 is fixed to the end of the base 84, and the pressing member 90 is fixed to the end of the core 89 passing through the chuck body 86. The end 93 is in contact with the rear end of the eraser 62 fitted in the guide cylinder 83. At the rear end of the joint 80 #, there is provided a portion that can be fitted to a connecting cylinder shaft 81 # that transmits an operation such as knocking, and at the tip of the pushing member 90, a guide is provided when the pushing member 90 moves forward most. A flange portion 91 is formed which comes into contact with the holding portion 83 # of the cylinder 83 and is prevented from moving.

FIGS. 11 and 12 show a third embodiment of a double-type writing instrument. In this embodiment, a pencil pencil writing body 100 and an eraser feeding body 101 are used.
A front barrel 103 and a middle barrel 104, each of which includes one element and is hollow from the front end to the rear end where any of the elements protrude, and a rear part of the front barrel 103 and the middle barrel 104. A cap body 105 wrapped and movable forward and backward along the front and rear barrels 103 and 104; and an outer peripheral wall of the cap body 105 which is swingably supported by a rear portion of the cap body 105. And a pendulum 107 for selecting an arbitrary one of the two elements by advancing the cap body 105 and projecting it from the front end of the front barrel 103. A writing state maintaining mechanism 108 for maintaining the protruding state of the arbitrary element, and a writing body immersion section (a pressing portion 106b at the rear end of the clip body 106 and a front end portion 106c) for immersing the protruding element. The clip body 106 has a front end urged toward the axial center of the center barrel 104, and has a slit 109a in the center of the front end lower part. Is provided.

The rear end 109b of the locking portion 109 is firmly fixed to the inner surface of the clip body 106 on the cap body side. (By spot welding, etc.)
08 is the slit 1 in the cap body 105.
09a is provided with a partition portion at a location facing the opening portion, and at both sides thereof, that is, at a location facing the locking portion 109, a window portion 110 formed so as to expose the inside of the cap body 105, A hole 111 drilled toward the inside of the central barrel 104 at a position of the central barrel 104 at which the locking portion 109 faces when it is advanced to a position where an arbitrary element projects, and a rear end surface of the hole 111 111a is the locking portion 109
It is formed in the shape to be locked. In addition, a cut groove is provided on both sides of the rear end of the hole 111, and the clip body 10 is formed therein.
6 The lower side edge 109c of the front end is fitted so that the locking portion 109 is securely locked to the rear end face 111a.

The double-type writing instrument will be described in more detail. (Front barrel 103, middle barrel 104) Both the forward barrel 103 and the middle barrel 104 are hollow, and the outer periphery thereof forms the outer wall of the main body of the double writing instrument. The tip barrel 103 has a roughly cylindrical shape that tapers gently, has a significantly tapered front end, and has an opening 103a. Tip barrel 1
At the rear end of the shaft 03, there is formed a connecting portion 103b which is thinned with a step and has a thread groove on the outer periphery, and the thinned connecting portion 103b is slightly expanded in the front end portion of the center cylinder 104 to form an inner peripheral portion. Is screwed and connected to the connection portion 104a having a thread groove. In the connected state, an annular decorative ring 112 is sandwiched between the stepped portion of the front barrel 103 and the tip of the center barrel 104. A guide cylinder 11 that slidably accommodates each of the above elements is provided in the rear portion of the center cylinder 104.
3 is inserted. In addition, the cylinder of this embodiment may be one body or may be divided into three or more.

(Center barrel 104) Also, on one side of the peripheral side surface of the center barrel 104 where the clip body 106 is provided, the hole 1 is provided.
On the other side, a guide groove 104b extending along the axial direction is formed on the other side to the middle of the rear end, and penetrates the rear end of the guide groove 104b toward the outer peripheral surface. A locking hole 104c is formed. The hole 111
Is formed in a plane perpendicular to the axis. Further, as described above, cut grooves are formed on both sides of the rear end face 111a. (Not shown) When the guide cylinder 113 is fitted into the center cylinder 104, the guide cylinder 1 is inserted into the guide groove 104b.
The engagement end portion 113h described later is fitted and slid, and the rear end portion of the engagement end portion 113h is formed so as to be fitted and locked in the locking hole 104c. Also, the guide cylinder 1 is provided on the inner peripheral surface on the rear side of the location where the hole 111 is formed.
A locking step portion 104d is formed for locking so as not to go rearward beyond a predetermined position when the fitting 13 is inserted into the center cylinder 104, and the inner peripheral surface further rearward of the locking step portion 104d is substantially cylindrical. It is formed in a shape.

The locking step 104d of the center cylinder 104
The clip body 10 is provided on the hole 111 side behind the
6 is formed so as to be movable back and forth. On the outer peripheral surface of the rear end portion of the center barrel 104, three guide ribs 104f projecting outward and extending in the axial direction are formed at intervals of, for example, 90 degrees except for the window 104e. And the inner peripheral surface of the rear end portion is provided with a locking step portion 104g having a reduced opening diameter.
Are formed. As described later, in this rear end,
The joint 115 is slidably fitted, and the locking step 104g and the step 115a on the outer periphery of the joint 115 are locked so that the joint 115 does not come off from the middle barrel 104. .

(Guide Tube 113) The guide tube 113 has sliding grooves 113b and 113c partitioned by partition walls 113a for accommodating the above-mentioned elements, respectively.
b and 113c include return springs 113d and 11d.
Sliding pieces 114a, 11 urged rearward at 3e
4b is slidably inserted therein. The return springs 113 d and 113 d are provided inside the front end of the guide cylinder 113.
e is formed with an inner step portion 113f for locking e. An opening 113g for allowing the tip of the pendulum 107 to swing and pass therethrough is provided at the rear end of the guide cylinder 113, and at the opposite side of the side where the clip body 106 is disposed around the axis of the center cylinder 104. The rear portion has a small width and a rear end portion and a projection bulging outward in the axial radial direction. An engagement end 113h for engaging the guide cylinder 113 with the center cylinder 104, and a contact step 113i with which the sliding pieces 114a and 114b urged inside the rear end abut are provided.

(Element; mechanical pencil 100)
Eraser unwinder 101) Mechanical pencil 1
00 is a core pipe 1 connected to the core feeding mechanism 100a at the front end and a core feeding mechanism 100a at the rear end.
00b, and the rear end of the core pipe 100b fits into the sliding piece 114a. Further, the eraser feeding body 101 has a guide cylinder 101a at the front end of which the eraser 102 is fitted. (Similar to the eraser dispensing body 61 described in the second embodiment) and a receiving pipe 100c is provided at the rear end.
A sliding piece 114b is fitted on the rear end of the sliding piece 114b.

(Cap body 105) Cap body 105
Is formed in a substantially cylindrical shape with a very gentle tapered outer shape, and a fitting 115 is fitted and fixed therein. or,
The cap body 105 is formed such that a cut window 105a penetrating from the outside to the inside on the window portion 110 side (the hole portion 111 side of the middle barrel 104) when viewed from the axial center extends in the axial direction with a predetermined width. The clip body 106 projects outward from the cut window 105a and extends forward. Also, the cap body 10
5 is provided with a guide rib 104f of the center cylinder 104.
Slidably fit into the shaft barrel 104 and the cap body 10.
5 are formed at three locations corresponding to the guide ribs 104f for freely moving in the axial direction and fixing in the rotational direction. At the rear end of the cap body 105, there is formed a cylindrical rear end shaft portion 105d having a small diameter at the rear via a step portion 105c.
A crown part 105e, which is formed in a substantially hemispherical shape so as to cover it from the rear and connect the outer peripheral surface thereof to the outer peripheral surface of the cap body 105, is detachably fixed to d.
In this embodiment, the outer peripheral surface of the rear end shaft 105d and the crown 1
Threads corresponding to each other are formed on the inner peripheral surface of 05e and are stopped by screwing them together. The step 105
An annular stop ring 105f is provided between the rearwardly facing surface of c and the front end of the crown 105e.

(Joint 115) The joint 115 has a substantially cylindrical shape, and has a center cylinder 104 and a cap body 105.
It is formed so that it can be installed inside. Further, the joint 115 has an opening at the front end and the rear end in the axial direction, and partition walls 115b # and 115b are formed at two places spaced apart from each other at a position slightly entering from the opening. . Holes 115c and 115d having different diameters of concentric circles are formed inside the joint 115 from the opening at the front end.
c, 115d, the inner diameter of the rear hole 115d is smaller than the front hole 115c with the step 115e formed in front of the partition wall 115b # as a boundary. A fulcrum 107a at the rear end of the pendulum 107 is provided by a cup-shaped holding member 116 at a location surrounded by a hole 115d rearward from the step 115e.
Is locked. The outer peripheral surface of the presser 116 is tightly fitted into the rear hole 115d, and the outer peripheral surface of the flange-shaped expanding portion 116a is formed in the front hole 115d.
c, and pendulum 107 is centered on the axis.
Hole 11 for inserting and supporting the main body so as to freely swing by its own weight
6b is formed. The cap body 10 is provided between the front end surface of the holding member 116 and the rear end surface of the guide cylinder 113.
A spring 117 for repelling the rearward of the spring 5 is interposed.

Also, both partition walls 115b of the joint 115 are provided.
115b is a recess 115h that opens toward the mounting side of the clip body 106 and has a substantially rectangular cross section perpendicular to the axial direction. This recess 115
A clip body 106 is rotatably supported in h by a shaft support portion 106a formed parallel to the opening end and slightly forward. On the opposite side of the lower rear end of the concave portion 115h, a spring seat portion 115i which is lower by one step is formed. Between the spring seat portion 115i and the clip body 106, the front end of the clip body 106 is centered on the axis. A clip body spring 106d for urging the clip body is provided.

Further, on the side of the clip body 106 on the side wall behind the partition 115b and the partition 115b of the joint 115,
Notch 115 for stroke in which clip body 106 swings
f is formed. The opening behind the partition 115b is a hole 115g having the same diameter and the same diameter as the hole 115g. In the hole 115g, a substantially cylindrical eraser 118 is fitted and attached with a cylindrical eraser stopper 118a. still,
On the outer peripheral surface of the front end of the joint 115, the center cylinder 104
An outer peripheral step portion 115a is formed to engage with the locking step portion 104g on the inner peripheral surface of the rear end portion. Protrusion 105g
Is formed with a wide groove 115j.

(Clip body 106) Clip body 106
Extends axially forward along the outer peripheral surface of the cap body 105, and is formed in a hollow shape by, for example, bending a metal plate material in the embodiment. Further, the clip body 106 is bent from the outer peripheral surface of the clip body 106 toward the axial center and rearward, and further bent outward in the vicinity of the outer peripheral surface of the cap body 105, and the cross-sectional shape of the distal end portion is roughly. It is formed in a triangular shape. Therefore, this clip body 1
The portion facing the inside rear of the tip of 06 is the locking portion 109. Further, as described above, the slit 109a is provided at the center, and the side edge 109c is firmly fixed by spot welding or the like. In addition, the clip body 106 is connected to the joint 11 so that the distal end thereof is positioned at the window 110 of the cap body 105.
5 is attached.

(Writing state maintaining mechanism 108) In the writing state maintaining mechanism 108, the cap body 105 advances and the clip body 106 enters the hole 111 through the window 110,
The locking portion 109 locks the rear end face 111a of the hole 111. (Writing body immersion portion) The writing body immersion portion includes a portion rearward from the support shaft of the clip body 106, a portion of a slope bent toward the axial center and rearward from the outer peripheral surface of the distal end portion of the clip body 106, and a cap body. 105 outside surface.

Although two elements are provided in the second and third embodiments, three or more elements may be provided. In that case, the first one is a mechanical pencil with a black core, the second one is a mechanical pencil with a colored core, and the third one is an eraser dispenser.

As a method for producing a colored sharp core used in the above-described dual writing instrument of the present invention, a perhydropolysilazane-containing liquid is impregnated into pores of at least a specific fired porous core made of a body material, and a nitrogen atmosphere or the like is used. It has been found that the problem can be solved by generating 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 compounded composition containing at least a body material and an organic excipient. 1
Forming a fired core, heating the first fired core in an oxidizing atmosphere to form a second fired core made of at least a constitutional material obtained by oxidizing and removing a carbide binder; In the pores, impregnated with a liquid containing perhydropolysilazane,
Forming a third fired core in which silicon nitride is formed by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere, and forming the third fired core with a colorant having excellent light resistance and weather resistance; It is a colored high strength fired sharp core. or,
A high-strength fired sharp core characterized in that pores of the third fired core are filled with a coloring agent having excellent light resistance and weather resistance.

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

The extender is not particularly limited as long as it is conventionally used for firing type color pencils, and any of them can be used. For example, a white base material such as titanium oxide, mica, talc, boron nitride, silica, alumina, or calcium carbonate, or a colored base material such as molybdenum disulfide or tungsten disulfide depending on the hue can be used. 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 excipient 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, and the like. Cellulose, natural polymer substances such as tragacanth gum, petroleum asphalt, coal tar pitch, naphtha cracked pitch,
Any pitch, such as carbonized pitch, such as synthetic resin, can be used. Naturally, a mixture of several types of these can also be used.

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

After sufficiently kneading these compounded compositions with a Henschel mixer, a pressure kneader, a two-roller or the like, they are extruded into a thin wire or the like by an extruder, and then inertized in a nitrogen atmosphere or an argon gas or the like. 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 excipient as a binder is obtained. The obtained first fired core body is a core body in which pores and carbide binders generated by firing are fine and sufficiently present, are uniformly dispersed, and the orientation material is highly oriented.

In order to increase the strength of the second fired core and improve the handleability, the compounded composition for obtaining the first fired core may optionally contain an inorganic material such as bentonite or kaolin. A binder may be blended, and when the blending amount is less than 25% by weight, the strength of silicon nitride described later is easily developed. If necessary, the first fired core obtained above was impregnated with a liquid containing perhydropolysilazane, and silicon nitride was formed 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 fired core obtained above is heated in an oxidizing atmosphere to oxidize and remove the binder of the carbide, thereby obtaining a second fired core comprising a porous core having a large number of pores. . Here, the pores of the second calcined core are formed by calcining a kneaded material composed of a constitutional material and an organic excipient in a non-oxidizing atmosphere, and removing the binder of the carbide. From the pores obtained by the above method. Adjustment of the porosity of the second calcined core is mainly performed by adjusting the blending ratio of the organic excipient, but it is also possible to appropriately add a pore forming material such as a carbon particulate material in addition to the above. I don't care. The amount of pores by removing 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 are uniformly dispersed. It is a core body in which the material is highly oriented. Thereby, the second fired core obtained from the first fired core is useful for obtaining the desired high-strength fired colored sharp core.

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

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 a binder, resulting in a higher yield. The mechanical strength of the resulting third fired core becomes strong. However, if the porosity of the second fired core exceeds 80%, the shape of the core is difficult to maintain, and the impregnation step with the liquid containing perhydropolysilazane becomes difficult. If the porosity is less than 30%, the amount of the perhydropolysilazane-containing liquid is small, and a remarkable improvement in mechanical strength cannot be expected.
Further, if the porosity is less than 30%, the amount of ink to be filled in the obtained third fired core body is small, and practical coloring and density cannot be obtained, which is not preferable. Therefore, the range of the porosity of the second fired core is 30 to 80%, but in order to improve the quality of the obtained third fired core, it is preferably 35 to 75%. preferable.

The perhydropolysilazane used to obtain the third fired core is a ceramic precursor polymer, has a [-Si-N-] structure in the main chain, and has only hydrogen bonded to a side chain. In the general formula, [SiHaN
b] n (where a is 1 to 3, b is 0 or 1),
The structure mainly has a skeleton of [-SiH2 NH-] n. Further, only hydrogen is erased by thermal decomposition in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere, and silicon nitride as a binder can be obtained in a very high yield. The generated silicon nitride is mostly trisilicon tetranitride [Si3 N4], but may be present in a slightly different form [Six Ny] depending on the raw materials used, heat treatment conditions and the like.

Further, since it does not contain an organic component such as a methyl group, a colorless, transparent and high-purity silicon nitride containing no carbon can be obtained. Further, the obtained silicon nitride has a lower temperature than other sintering methods, that is, the sintering method obtained from silicon powder is 1200 ° C.
Although the treatment is 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 obtained by dissolving the above-mentioned perhydropolysilazane with an organic solvent. If the perhydropolysilazane-containing liquid is capable of impregnating the second fired core, the organic solvent to be used is used. Is not particularly limited, and any of them can be used. Examples of the organic solvent to be used include organic solvents such as benzene, toluene, xylene, tetrahydrofuran (THF), methylene chloride, carbon tetrachloride, and aromatic hydrocarbons.

As a method for impregnating the second fired core with the perhydropolysilazane-containing liquid, the second fired core is immersed in the perhydropolysilazane-containing liquid and, if necessary, heated, depressurized, and pressurized. This can be done by impregnating underneath. Here, the impregnation state of the perhydropolysilazane-containing liquid impregnates and impregnates finely and uniformly in the second fired core. That is, as described above, the second fired core body has fine pores which are sufficiently present and are uniformly dispersed, the body material is highly oriented, and a high-strength fired colored sharp core body is obtained. Is useful for
The perhydropolysilazane-containing liquid is finely and uniformly dispersed and impregnated in the second fired core. In addition, in order to obtain a high-strength third fired core, if necessary, the impregnation with the liquid containing perhydropolysilazane and the firing step may be repeated.

In the obtained third fired core, silicon nitride as a binder is formed by being finely and uniformly dispersed in the core, and a small amount of nitride is formed because the base material is highly oriented. The production of silicon makes it easy to develop the strength of the core, and the collapse of the core during writing becomes uniform.

The high-strength fired colored sharp core is obtained by filling the pores of the third fired core obtained above with a coloring agent having excellent light resistance and weather resistance. As a coloring agent to be filled, a dye having excellent light resistance and weather resistance is added to 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, the use of a pigment is conceivable.However, it is not possible to color the inside of the core simply with a dispersion of water, an organic solvent, or the like. A method of impregnating an organic pigment dissolved in an organic solvent or the like, further solidifying the pigment by means such as water precipitation in open pores, impregnating a liquid containing a pigment precursor into the open pores of the core, and further opening The pigment can be filled into the core by a method of causing 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 causing a rake reaction in the open pores to form a pigment.

In any of the above-mentioned coloring agent filling methods, in order to promote the impregnation, it is possible to perform the impregnation under heating, reduced pressure, and pressure, or to perform the impregnation in the presence of a surfactant or other additives. It 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.

Further, it is possible to improve the lubricity at the time of writing by impregnating the extra open pores with oil or the like. In order to be able to erase as much as a fired black core (black core) with an eraser, it is necessary to select from oils and fats and / or waxes which are liquid at normal temperature. Specific examples include silicone oil, mineral oil, liquid paraffin, and α-olefin oligomer.

[0067]

In the first embodiment, FIG. 3 shows a state where the writing portion is stored. First, as shown in FIG.
When the rear end 29 is engaged with the stopper 8 of the partition 3 of the rear shaft 1, the front end of the color pencil mechanical pencil 44 becomes the front shaft. 45
Protruding from the front end hole 48. At this time, knock operation unit 33
The rear end 29 is engaged with the stopper 8, and the end spring 28 of the knock operation section 33 can contract the return spring 47 by a knock stroke necessary for feeding out the color core 49.

When the knock operation unit 20 is knocked in this state, the protrusions 24 and 25 are moved to the knock operation unit 33 in the forward position.
Of the writing body 41 such as a ball-point pen is protruded from the distal end hole 48 of the front shaft 45 and engaged with the pen. At that time,
The end portion 22 of the knock operation portion 20 is provided with a return spring 40.
Is substantially fully compressed, the rear shaft 1 is prevented from shifting with respect to the front shaft 45. (However, it is also possible to form so that the end of the knocking operation part abuts on the end of the joint without fully compressing the return spring.) At that time, the knocking stroke should be within the range not reaching the stopper 8 position. If adjusted, the storage state shown in FIG. 3 is obtained.

FIG. 5 shows a state in which the tip of the mechanical pencil 42 for black core is projected from the tip hole 48. At this time, the rear end 29 of the knock operating section 32 is engaged with the stopper 8. In this state, the return spring 47 can be contracted by the knock stroke necessary for feeding the lead at the end 28 of the knock operation section 32. Therefore, the rear end portion 4 of the rear shaft 1 is knocked with respect to the front shaft 45 by a gap 34 having the same value as a knock stroke formed in the axial direction by fitting the groove 13 of the joint 9 and the projection 6 of the rear shaft 1. Then the wick is extended. The eraser 50 and the color core 49 are similarly fed when the tip of the eraser feeding body 43 and the tip of the above-mentioned mechanical pencil 44 for the color core protrude from the tip hole.

FIG. 8 shows a cylindrical cam 5 according to the second embodiment.
7 is engaged with the sliding piece 59 of one mechanical pencil writing body 60 so that the writing portion 60 #
Is projected from the tip hole 56 # of the front shaft, and at this time, the flange 71 of the cylindrical cam 57 exists at the position of the wide portion of the circumferential groove 65. If the rear end of the knock cover decoration 78 protruding from the rear end of the rear shaft 58 is knocked in this state, the knocking force is transmitted to the core pipe 81 via the cylindrical cam 57 and the sliding piece 59, and The core is extended by the axis transition, and writing is possible. Next, the rear shaft 58 is rotated with respect to the front shaft 56 so that the notch at the tip of the cam slope 70 of the cylindrical cam 57 and the sliding piece 59 of the mechanical pencil 60 are drawn.
Is disengaged, and further rotation continues, the sliding piece 59 of the mechanical pencil 60 is retracted by the cam slope 70 of the cylindrical cam 57, and the sliding piece 59 # of the other eraser feeding body 61 is advanced, The writing portion 60 # of the mechanical pencil 60 is immersed in the tip shaft 56 and is replaced with the eraser feeding body 61. Further, when the rear shaft 58 is rotated, the notch at the tip of the cam slope 70 of the cylindrical cam 57 and the sliding piece 59 # of the eraser feeder 61 engage with each other in a state where the rear shaft 58 is rotated by approximately 180 °, so that the eraser 62 is projected, and the knocking is performed. If the rear end of the cover decoration 78 is knocked, the eraser 62 can be extended.

In the third embodiment, the writing state of the writing body is maintained by the writing state maintaining means. This writing state maintaining means has a configuration in which a locking portion of the clip body is engaged with a window portion drilled toward the inside of the cylindrical body. Therefore, when the cap body is moving forward, the locking portion of the clip body in the state maintaining means is deeply immersed into the hole of the cylindrical body through the window of the cap body, and the rear end face of the hole is formed. As a result, the locking portion is deeply engaged with the hole, and can be reliably locked. Therefore,
It is possible to reliably maintain the locked state of the cursive writing. By the way, if a writing instrument is inserted into a breast pocket or the like via a clip body in a normal configuration, the cloth will be deeply immersed in the hole of the cylindrical body. There is a risk that the pockets and the like may be damaged by engaging with the locking portions of the body. However, according to the present application, since the partition is provided at the center of the window of the cap body, the cloth does not sink into the hole of the cylindrical body, so that the clip body can be smoothly inserted and removed from the pocket, and there is a risk of damaging the cloth. Absent. The writing body can be made to protrude by holding the cylindrical body with the hand and pressing the cap body with the finger of the hand. Therefore, operability is good because the operation can be performed with one hand instead of both hands.

Also, since the writing body immersion portion includes a cylindrical side surface at the front end portion of the clip body formed on a slope facing the center of the cylinder axis and toward the rear, the double writing implement can be used to attach any writing body. Even if the clip is engaged with the outer edge of the pocket by inserting it into the pocket with it protruding, the locking portion of the clip body is separated from the cylindrical body, whereby the locking of the locking portion is released and protruded The body is automatically immersed. Therefore, even if the double-type writing instrument is inserted into the pocket of the clothes, the clothes can be reliably prevented from being stained.

[0073]

As described above, the present invention relates to a double-type writing instrument in which a plurality of writing elements, such as writing elements, can be selectively protruded and retracted from a tip hole of a front shaft.
A sharp pencil writing body with a built-in black sharp lead as the main body, and at least one other as a pencil pencil writing body with a built-in colored sharp core other than black, the colored sharp lead being a core that can be easily erased with an eraser. The colored sharp core used is a fired porous pencil core that solves the drawbacks of the conventional cores described above. It maintains strong strength and produces bright colors to achieve light resistance and weather resistance. It has excellent characteristics such as excellent line drawing and erasability by an eraser.It is also excellent in portability, easy to write and erase, and it is possible to mount an erasable color core other than black. It is possible to provide a convenient double-type writing instrument.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a double-type writing instrument according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a developed state of components in the first embodiment.

FIG. 3 is a longitudinal sectional view of the writing unit in a stored state.

FIG. 4 is a longitudinal sectional view showing a state in which a writing tip on a colored core side projects from a tip end hole.

FIG. 5 is a longitudinal sectional view showing a state in which a writing tip on the black core side is projected from a tip hole.

FIG. 6 is a cross-sectional view of a rear shaft portion in a knock operation unit.

FIG. 7 is a cross-sectional view of the rear shaft portion when one knock operation portion is advanced to the shaft tip.

FIG. 8 is a longitudinal sectional view showing the whole of a double-type writing instrument according to a second embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of an eraser dispensing element.

FIG. 10 is an external view of a guide cylinder used for an eraser dispensing element.

FIG. 11 is a longitudinal sectional view showing the entirety of a double-type writing instrument according to a third embodiment of the present invention, showing a state in which elements such as a writing body are stored.

FIG. 12 is a longitudinal sectional view showing the entirety of a double-type writing instrument according to a third embodiment, and shows a state in which the tip of an eraser dispensing body is projected from a tip end of a front shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rear shaft 2 Vertical groove 3 Partition 7 Engagement part 8 Stopper 9 Joint 10 Engagement part 11 Hole 20 Knock operation part 21 Lock part 23 Rear end part 24 Projection 25 Projection 26 Knock operation part 29 Rear end part 32 Knock operation part 33 Knocking operation part 40 Return spring 41 Writing body such as ballpoint pen 42 Mechanical pencil writing body 43 Eraser feeding body 44 Mechanical pencil writing body 45 Front shaft 47 Return spring 48 Front hole 49 Color core 50 Eraser 55 Guide tube 56 Front shaft 57 Cylindrical cam 58 Rear shaft 59 Sliding piece 59 ° Sliding piece 60 Mechanical pencil writing body 61 Eraser unreeling body 62 Eraser 63 Guide groove 63 ｀ Guide groove 65 Peripheral groove 70 Cam slope 71 Flange 77 Knock cover 78 Knock cover decoration 81 Core pipe 81 ｀ Connection Shaft 82 Return splice 82 82 Return spring 83 Guide cylinder 84 Cap 85 Shaft portion 86 Chuck body 88 Tightening ring 96 Chuck spring 89 Core material 90 Push member 100 Mechanical pencil writing tool 101 Eraser unwinding body 103 Front barrel 103a Tip hole 104 Middle barrel 105 Cap body 105a Cutout window 105b Guide groove 106 Clip body 106a Shaft support 107 Pendulum 108 Writable state maintaining mechanism 109 Locking section 109a Slit 110 Window section 111 Hole section 114a Sliding piece 114b Sliding piece 111a Rear end face 115 Joint 115h Recess 115i Spring seat Part 116 Holder 117 Spring

Claims (1)

[Claims] 1. A double-type writing instrument in which the tip of each writing body can be selectively protruded and retracted from a tip end of a front shaft, wherein, of the writing bodies, the first is an eraser dispenser and the second is a black sharp. A pencil pencil with a built-in core and at least one other pencil with a colored non-black sharp pencil with a built-in pencil. The eraser or sharp core can be fed out by knocking the end, and the colored sharp core is obtained by impregnating a porous fired core with a dye or pigment ink, and its writing line is eraser. A double-type writing instrument that can be easily erased.