JP2011093238A - Multi-core chamber type writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of clogging or jamming of core bodies upon selecting and delivering of a core body when deformed core bodies having cross sections such as an oblong, rectangle, polygon, star and ellipse are used, in a conventional multi-core chamber type writing utensil in which core bodies are housed in an outer shaft and a plurality of core chambers radially provided in the outer shaft. <P>SOLUTION: In the multi-core chamber type writing utensil, core bodies of deformed cross sections are housed in a plurality of core chambers radially installed in the outer shaft, and a middle shaft having a core body-introducing hole that can oppositely face one of the core chambers is arranged in the outer shaft so as to be rotatable and movable forward and backward. Also, in the writing utensil, there is arranged a core body holding means which is arranged so as to be movable forward and backward, energizing the middle shaft rearward with a resilient member and which is successively provided in the front of the middle shaft so as to be unrotatable, holding and releasing the core bodies. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention accommodates a deformed core body having a rectangular or rectangular cross section, a polygonal shape, a star shape, an ellipse, or the like in an outer shaft and a plurality of core chambers provided radially in the outer shaft. A core guide hole that can be opposed to one of the two is provided, a center shaft that is rotatably disposed in the outer shaft and is capable of moving forward and backward, and is disposed non-rotatably in front of the center shaft, and the core body passes therethrough. A relay shaft having a hole to be opened, a core body gripping means that is non-rotatably disposed in front of the relay shaft to grip and release the core body, and a tip metal that contacts the core body gripping means in front of the outer shaft. The present invention relates to a writing instrument characterized by being arranged so as to be rotatable with respect to a shaft.

Conventionally, a core body guide hole having an outer shaft, a plurality of core chambers radially arranged in the outer shaft, and an opening that can face one of the core chambers is provided, and the core body is gripped at the front portion. An open core body gripping means is provided in series, a middle shaft that can be moved forward and backward in the outer shaft and rotatably, a pair of elastic lids fixed to the middle shaft, A multi-core writing instrument has been devised that includes a pair of engaging portions provided at arbitrary locations and an engaging piece that is located between the engaging portions by advancing the center axis and that allows the engaging portions to be separated. One example is Japanese Utility Model Publication No. 63-016552.
In addition, in order to grip a core body having a rectangular cross section, a flat core chuck having a U-shaped core body sandwiching with a flat cross section has been proposed. Japanese Utility Model Publication No. 2-106386.
Japanese Utility Model Publication No. 63-016552 Japanese Utility Model Publication No. 2-106386

  However, in the multi-core writing instrument described in Japanese Utility Model Publication No. 63-016552, a core body having a circular cross section is housed in a core chamber radially provided in the shaft cylinder, and the user selects an appropriate core type. Although it is used for feeding, irregular cores such as rectangles, rectangles, polygons, stars and ellipses have directionality, so there are problems such as biting and feeding failure in core selection and feeding. May occur.

  According to the present invention, a core body having an irregular cross section is accommodated in a plurality of core chambers provided radially on the outer shaft, and a center shaft provided with a core body guide hole that can face one of the core chambers is provided inside the outer shaft. The middle shaft is urged rearward by a resilient member, and is connected to the front of the middle shaft in a non-rotatable manner and holds the core body. Further, the gist of the present invention is that the core holding means for opening is disposed.

  According to the present invention, a core body having an irregular cross section is accommodated in a plurality of core chambers provided radially on the outer shaft, and a center shaft provided with a core body guide hole that can face one of the core chambers is provided inside the outer shaft. The middle shaft is urged rearward by a resilient member, and is connected to the front of the middle shaft in a non-rotatable manner and holds the core body. Further, by arranging the core holding means for opening, it becomes possible to prevent problems such as the biting of the core and the feeding failure in the selection of the core and the feeding of the core as much as possible.

Sectional drawing which shows the structure of 1st Example of this invention. The front view of a core body holding part. The detailed sectional view of a core grasping part. Sectional drawing of a core chamber. Detailed sectional drawing of a tail plug part. Operation diagram of center feeding. Detailed operation diagram of tail plug portion of core feeding. Sectional drawing which shows the structure of 2nd Example of this invention. The detailed sectional view of a core grasping part. Sectional drawing of a core chamber. The perspective view of a cylinder. The perspective view of a tail plug. Detailed sectional drawing of a tail plug part. Operation diagram of center feeding. Detailed operation diagram of tail plug portion of core feeding. Sectional drawing which shows the structure of 3rd Example of this invention. The detailed sectional view of a core grasping part. Detailed sectional drawing of a cylinder. The perspective view of a cylinder. The perspective view of a tail plug. Detailed sectional drawing of a tail plug part. Operation diagram of center feeding. Detailed operation diagram of tail plug portion of core feeding.

  A first example will be described with reference to FIGS. In FIG. 1, the writing instrument of the present invention is roughly divided into four parts. The core body gripping part that grips or releases the core body, the outer shaft part that stores the core body, the central shaft part that serves as a passage for guiding the core body from the storage part to the core body gripping part, and the core body are selected and fed out. It is the tail plug part.

  The core body gripping portion includes a chuck body 2 that grips and opens the deformed core 1 and a tip member 3 that is positioned behind the chuck body 2. The chuck body 2 and the tip member 3 are made of a metal material, but may be made of a resin material. A rear conical portion 2 a is formed behind the chuck body 2, and the rear conical portion 2 a is in contact with a slope 3 a formed on the front inner surface of the tip member 3. The chuck body 2 is composed of two chuck pieces 2b (2c). Inside each chuck piece 2b (2c), there is a groove 2d slightly larger than the cross-sectional shape of the deformed core used. Is formed. Since the cross-sectional shape of the irregular core used in this example is rectangular (rectangular), the groove 2d is also a U-shaped groove into which the rectangular irregular core is fitted.

  As shown in FIG. 3, the outer shaft portion includes an outer shaft 4 and a resilient member 5 such as a coil spring disposed inside the outer shaft 4. The tip member 3 is rotatably inserted in the front end of the outer shaft 4, but the flange 3 a formed at the substantially central portion of the tip member 3 is prevented from entering the outer shaft 4. Yes. Here, in order to improve the relative rotation of the tip member 3 with the outer shaft 4, a lubricant may be interposed between the tip member 3 and the outer shaft 4, or at least one of them may be interposed. A fine uneven portion may be formed on the contact surface. Further, a step 4a having a reduced diameter is provided on the front inner surface of the outer shaft 4, and one end of the elastic member 5 is in contact with the step 4a. On the other hand, the other end portion of the resilient member is in contact with a step portion of a relay shaft, which will be described later, and biases the relay shaft and the chuck body 2 toward the rear. Further, a plurality of protrusions are formed on the inner surface of the outer shaft 4 in the longitudinal direction and at radially spaced positions in the circumferential direction, and a space portion formed between the adjacent protrusions. Is a core chamber 4b for accommodating the core. A circumferential groove 4c is provided behind the core chamber 4b.

The middle shaft portion includes a relay shaft 6, a middle shaft 7 fixed to the rear of the relay shaft 6, and a lid body 8 disposed on the middle shaft 7. The relay shaft 6 and the middle shaft 7 cannot be rotated relative to each other. On the inner surface of the relay shaft 6, a through hole 6a having a cross section matching the shape of the irregular core to be used is formed. In this example, it is a rectangle (rectangle). The chuck body 2 is fixed to the front end of the relay shaft 6 in which the rectangular through hole 6a is formed with the same rectangular direction. A step portion 6b is formed on the outer peripheral surface of the substantially central portion of the relay shaft 6, and the other end portion of the elastic member 5 is in contact therewith. Then, the relay shaft 6 is urged rearward by the resilient member 5 and the intermediate shaft 7 and the chuck body 5 fixed to the relay shaft 6 are also urged rearward. . The chuck body 5 is also fixed so as not to rotate relative to the relay shaft 6. That is, the intermediate shaft 7, the intermediate shaft 6, and the chuck body 5 are integrated with each other so as not to rotate. Further, a rectangular groove 7a for guiding the deformed core is also formed on the inner side of the middle shaft 7 so as to extend from the front end to the rear end, and the direction of the rectangular through hole 6a of the relay shaft 6 is the same. is doing.
The groove 7a is provided with a lid 8 made of a metal material but capable of elastic deformation. The rear portion of the lid 8 is formed with an engaging portion 8a formed in a box shape, and the box-shaped engaging portion 8a engages with a protrusion 7b formed in the rear portion of the groove 7a. ing. A concave portion 8b is formed in the rear portion of the lid body 8, and a projection of a tail plug, which will be described later, can come into contact with the concave portion 8b.

The tail plug portion includes a tail plug 9 and a knob 10. The tail plug 9 is composed of a flange portion 9d exposed from the outer shaft 9 and a reduced diameter portion 9e attached to the outer shaft 4. A rib 9a is circular on the outer peripheral surface of the reduced diameter portion 9e. It is formed on the circumference. The circumferential rib 9a is rotatably engaged with a circumferential groove 4b formed at the rear end of the outer shaft 4. Further, a projection 9b is formed at the front end of the reduced diameter portion 9e of the tail plug 9 inward. The protrusion 9b is located in the concave portion 8b of the lid 8, and is engaged by entering the groove 7a of the central shaft 7.
The knob 10 is detachably attached to the rear portion of the middle shaft 6, and a notch 10 a is formed at the front end of the knob 10. In this example, the deformed core 1 housed in the core chamber 4b is composed of eight types of colored pencil cores. However, eight types of pencil leads having different hardnesses may be used, or a combination of a colored pencil lead and a pencil lead may be used.

  The core feeding method of the present invention will be specifically described. First, the deformed core to be used is selected, and the tail plug 9 is rotated relative to the outer shaft 4. By rotating the tail plug 9 relative to the outer shaft 4, the projection 9 b formed on the tail plug 9 rotates the middle shaft 7 and the lid body 8. Further, with the rotation of the intermediate shaft 7, the relay shaft 6 fixed to the intermediate shaft 7 and the chuck body 2 fixed to the relay shaft 6 also rotate. As the chuck body 2 rotates, the chuck body 2 and the tip member 3 try to rotate relatively. However, since the frictional resistance between the outer shaft 4 and the tip member 3 is low, the tip of the chuck body 2 is rotated. The member 3 easily rotates with respect to the outer shaft 4.

  Here, after selecting the irregular core, the knob 10 is pushed forward. When the knob 10 is pushed forward, the middle shaft 7, the relay shaft 6, and the chuck 2 connected to the knob 10 also move forward, and the chuck body 2 expands. At this time, the lid body 8 disposed on the middle shaft 7 is also moved forward by the forward movement of the middle shaft 7. By the advancement of the lid body 8, the projection 9b of the tail plug 9 is detached from the recess 8a of the lid body 8 and comes into contact with the surface of the lid body 8, and the lid body 8 is pushed down by the projection 9b. The lid and others 8 are bent toward the bottom of the groove 7a. Then, the deformed core 1 housed in the core chamber 4 b is dropped by its own weight by the bending operation of the lid body 8 and guided to the chuck 2. At the same time, the chuck body 2 is also expanded, and the deformed core 1 is fed out from the tip opening of the chuck body 2.

A second example will be described with reference to FIGS.
FIG. 8 also includes four parts. The core body gripping part that grips or releases the core body, the outer shaft part that stores the core body, the central shaft part that serves as a passage for guiding the core body from the storage part to the core body gripping part, and the core body are selected and fed out. It is the tail plug part.

The core body gripping part has the same configuration as the first example, and a detailed description of the structure is omitted.
The core body gripping portion includes a chuck body 32 that grips and opens the deformed core 31 and a tip member 33 that is positioned behind the chuck body 32. A conical portion 32 a is formed behind the chuck body 32, and the conical portion 32 a is in contact with a slope 33 a formed on the front inner surface of the tip member 33.

  As shown in FIG. 9, the outer shaft portion includes an outer shaft 34, a resilient member 35 such as a coil spring disposed inside the outer shaft 34, and a cylindrical body 36 fixed to the rear portion of the outer shaft 34. It consists of A cam surface 36 a made up of a plurality of chevron projections is formed on the front end surface of the cylindrical body 36. Further, a step 34a having a reduced diameter is provided on the front inner surface of the outer shaft 34, and one end of the elastic member 35 is in contact with the step 34a. On the other hand, the other end portion of the elastic member 35 is in contact with a step portion of a relay shaft described later, and biases the relay shaft and the chuck body 2 toward the rear. Furthermore, a plurality of protrusions are formed on the inner surface of the outer shaft 34 in the longitudinal direction and at radially spaced positions with respect to the circumferential direction, and a space formed between the adjacent protrusions. Is a core chamber 34b for storing the core. A circumferential groove 34c is provided behind the core chamber 4b. A circumferential protrusion 36b formed on the outer peripheral surface of the cylindrical body 36 is fitted in the circumferential groove 34c.

The middle shaft portion includes a relay shaft 37, a middle shaft 38 fixed to the rear of the relay shaft 37, and a lid body 39 disposed on the middle shaft 38. The relay shaft 37 and the middle shaft 38 cannot be rotated relative to each other. On the inner surface of the relay shaft 37, a through-hole 37a having a cross section matching the shape of the irregular core to be used is formed. In this example, it is a rectangle (rectangle). The chuck body 32 is fixed to the front end of the relay shaft 37 in which the rectangular through hole 37a is formed in the same rectangular direction. Further, a step portion 37 b is formed on the outer peripheral surface of the substantially central portion of the relay shaft 37, and the other end portion of the elastic member 35 is in contact therewith. The elastic member 35 biases the relay shaft 37 rearward, and the intermediate shaft 38 and the chuck body 32 fixed to the relay shaft 37 are also biased rearward. . The chuck body 32 is also fixed so as not to rotate relative to the relay shaft 37. That is, the middle shaft 38, the relay shaft 37, and the chuck body 32 are integrated so that they cannot rotate with each other. Further, a rectangular groove 38a for guiding the deformed core is also formed on the inner side of the intermediate shaft 38 so as to extend from the front end to the rear end, and the direction of the rectangular through hole 37a of the relay shaft 37 is the same. is doing.
The groove 38a is provided with a lid 39 made of a metal material but capable of elastic deformation. The rear portion of the lid 39 is formed with an engaging portion 39a formed in a box shape, and the box-shaped engaging portion 39a engages with a protrusion 38b formed in the rear portion of the groove 38a. ing. A recess 39b is formed in the rear part of the lid 39, and a projection of a tail plug, which will be described later, can come into contact with the recess 8b.
Reference numeral 38c is a circumferential collar formed on the outer peripheral surface of the intermediate portion of the shaft 38, and a front end portion of a tail plug 40 described later is in contact therewith.

The tail plug portion includes a tail plug 40 and a knob 41. The tail plug 40 includes a flange 40b exposed from the outer shaft 34 and a reduced diameter portion 40c attached to the outer shaft 34 through the cylindrical body 36. Further, a protrusion 40d is formed on the front end portion of the reduced diameter portion 40c of the tail plug 40 toward the inside. The protrusion 40d is located in the recess 39b of the lid 39 and is also engaged by entering the groove 38a of the central shaft 38. Further, a projection 40a is formed on the outer surface of the intermediate portion of the reduced diameter portion 40c, and the upper surface of the projection 40a is engaged with the cam surface 36a of the cylindrical body 36 so as to be detachable.
The front end portion of the tail plug 40 is in contact with the collar portion 38c of the biased middle shaft 38 that is biased rearward by the resilient member 35. That is, the tail plug 40 is also urged rearward by the elastic member 35. Due to the elastic force, a gap X is generated between the tail plug 40 and the cylindrical body 36, and the tail plug 40 can be moved forward against the urging force of the elastic member 35. It has become.
The knob 41 is detachably engaged with the rear end of the middle shaft 38.

  The core feeding method of the second example will be specifically described. As in the first example, the core is first selected, but the tail plug 40 is pushed forward in the axial direction with respect to the outer shaft 34. By pushing the tail plug 40 forward in the axial direction, the front end surface of the collar portion 40 b of the tail plug 40 comes into contact with the rear end surface of the cylindrical body 36 fixed to the outer shaft 34. By the advancement of the tail plug 40, the cam surface 36a formed at the front end of the cylindrical body 36 and the protrusion 40a formed in front of the tail plug 40 are disengaged, and the tail plug 40 is in the axial direction of the outer shaft 34. Can be rotated. At the same time, when the tail plug 40 is advanced, the intermediate shaft 38 and the relay shaft 37 with which the tail plug 40 is in contact, and the chuck body 32 fixed to the relay shaft 37 are also advanced. When the tail plug 40 is rotated while the chuck body 32 is advanced, the chuck body 5 is also rotated. When the chuck body 32 rotates, the rear cone portion 32a in the vicinity of the front end of the chuck body 32 and the inclined surface 33a provided on the tip member 33 are separated from each other. The tail plug 40 and the chuck body 32 can be rotated with a light force.

  Here, after selecting the deformed core 31, the knob 41 is pushed forward. When the knob 41 is pushed forward, the middle shaft 38, the relay shaft 37, and the chuck body 32 connected to the knob 41 also move forward, and the chuck body 32 expands. At this time, the lid 39 disposed on the middle shaft 38 is also advanced by the advance of the middle shaft 38. By the advancement of the lid body 39, the projection 40b of the tail plug 40 is detached from the recess 39b of the lid body 39 and comes into contact with the surface of the lid body 39, and the lid body 39 is pushed down by the projection 40b. The lid 39 is bent toward the bottom of the groove 7a. The deformed core 1 housed in the core chamber 34 b is dropped by its own weight by the bending operation of the lid 39 and guided to the chuck body 32. At the same time, the chuck body 32 is also expanded, and the deformed core 31 is fed out from the front end opening of the chuck body 32.

  A third example will be described with reference to FIGS. FIG. 15 also includes four parts. The core body gripping part that grips or releases the core body, the outer shaft part that stores the core body, the central shaft part that serves as a passage for guiding the core body from the storage part to the core body gripping part, and the core body are selected and fed out. It is the tail plug part.

  The core body gripping portion includes a chuck body 72 that grips and opens the deformed core 71, and a tip 73 that is positioned behind the chuck body 72. A rear conical portion 72 a is formed behind the chuck body 72, and the rear conical portion 72 a is in contact with the inclined surface 73 a of the tip 73.

As shown in FIG. 15, the outer shaft portion includes an outer shaft 74, a resilient member 75 such as a coil spring arranged inside the outer shaft 74, and a sleeve 76 fixed to the rear portion of the outer shaft 74. It is configured. Further, the tip 73 is rotatably inserted in the front inner surface of the outer shaft 74. Further, a step 74a having a reduced diameter is provided on the front inner surface of the outer shaft 74, and one end of the elastic member 75 is in contact with the step 74a. On the other hand, the other end portion of the elastic member 75 is in contact with a step portion of a relay shaft, which will be described later, and biases the relay shaft and the chuck body 72 rearward.
In addition, a plurality of protrusions are formed on the inner surface of the outer shaft 74 in the longitudinal direction and at radially spaced positions in the circumferential direction, and a space portion formed between the adjacent protrusions. Is a core chamber 74b for accommodating the core. And 74c is provided in the axial direction at the back of the core chamber 74b.
A circumferential groove 76a is formed on the inner surface of the sleeve 76, and a projection of a tail plug, which will be described later, is rotatably fitted.

The middle shaft portion includes a relay shaft 77, a middle shaft 78 fixed to the rear of the relay shaft 77, a cylindrical body 79 through which the middle shaft 78 passes, and a lid body 80 disposed on the middle shaft 78. A relay shaft 77 having a through-hole 77 a having a cross section matching the shape of the deformed core is fixed in front of the middle shaft 78, and a chuck body 72 is fixed to the front end of the relay shaft 77. A stepped portion 77a is formed on the outer peripheral surface of the substantially central portion of the relay shaft 77, and one end portion of the elastic member 75 is in contact therewith. The relay member 77 urges the relay shaft 77 toward the rear by the elastic member 75, and the intermediate shaft 78 and the chuck body 72 fixed to the relay shaft 77 are also urged toward the rear. Yes. A flange 78a is formed at the rear portion of the middle shaft 78, and a groove 78b for guiding the deformed core is formed on the inner side of the middle shaft 78 from the front end to the rear end. The rectangular groove 78b has the same direction as the rectangular through hole 77a of the relay shaft 77.
Further, a lid body 80 that can be elastically deformed is disposed in the groove 78b of the central shaft 78. An engagement portion 80a formed in a box shape is formed at the rear portion of the lid body 80, and the box-shaped engagement portion 80a engages with a protrusion 78c formed at the rear portion of the groove 78b. ing. A concave portion 80b is formed in the rear portion of the lid 80, and a projection of a tail plug, which will be described later, can come into contact with the concave portion 80b.
A cylindrical body 79 is fixed to the inner surface of the rear portion of the outer shaft 74, and a cam surface 79b formed of a plurality of chevron projections is formed on the rear end surface of the cylindrical body 79. Further, the cylindrical body 79 is in contact with a flange 78 a formed on the outer peripheral surface of the rear portion of the middle shaft 78. In other words, the cylindrical body 89 is urged rearward by the middle shaft 78 being urged rearward by the elastic member 75.

The tail plug portion includes a tail plug 81 and a knob 82. The tail plug 81 includes a flange portion 81c exposed from the outer shaft 74 and a reduced diameter portion 81d attached to the outer shaft 74 via the sleeve 76. Further, a projection 81e is formed on the front end portion of the reduced diameter portion 81d of the tail plug 81 inward. The protrusion 81e is located in the recess 80b of the lid 80, and is also engaged by entering the groove 78b of the intermediate shaft 78.
The front end surface of the reduced diameter portion 81d of the tail plug 81 is formed with a plurality of chevron-shaped concave and convex portions 81a, and a convex portion 81b is formed circumferentially on the outer peripheral surface of the substantially central portion. Yes. The concavo-convex portion 81 a of the tail plug 81 is detachably in contact with a cam surface 79 b formed at the rear end of the outer shaft cylindrical body 79. The concave and convex portions 81a and the cam surface 79b are engaged with each other by the urging force of the elastic member 75.
Although the circumferential convex portion 81b of the tail plug 81 is engaged with a groove 76a formed in the sleeve 76, the tail plug 81 and the sleeve 76 are capable of relative rotation. . The knob 82 is detachably attached to the rear end portion of the middle shaft 78.

  The core feeding method of the fourth example will be specifically described. As in the first example, the core is first selected, but the tail plug 81 is rotated relative to the outer shaft outer shaft 74. By the rotation of the tail plug 81, the concave and convex portion 81a of the tail plug 81 gets over the mountain-shaped cam surface 79b, and at this time, the cylindrical body 79 moves forward. By the advancement of the cylindrical body 79, the middle shaft 78 in contact with the front end surface of the cylindrical body 79 and the flange 78a is also advanced. The relay shaft 77 and the chuck 72 are also moved forward by the advancement of the intermediate shaft 78. As the chuck body 72 advances, the rear conical portion 72a in the vicinity of the front end of the chuck body 72 and the inclined surface 73a provided on the tip member 73 are disengaged. The tail plug 91 and the chuck body 72 can be rotated with a light force.

  Here, after selecting the irregular core, the knob 82 is pushed forward. When the knob 821 is pushed forward, the middle shaft 78, the relay shaft 77, and the chuck 72 connected to the knob 82 are also advanced, and the chuck body 72 is expanded. At this time, the lid 80 disposed on the middle shaft 72 is also moved forward by the advance of the middle shaft 78. By the advancement of the lid body 80, the projection 81e of the tail plug 81 is detached from the recess 80c of the lid body 80 and comes into contact with the surface of the lid body 80, and the lid body 80 is pushed down by the projection 81e. The lid and others 80 bend toward the bottom of the groove 78b. Then, the deformed core 71 accommodated in the core chamber 74 b is dropped by its own weight by the bending operation of the lid body 80 and guided to the chuck body 72. At the same time, the chuck body 72 is also expanded, and the deformed core 71 is fed out from the tip opening of the chuck body 72.

DESCRIPTION OF SYMBOLS 1 Deformed core 2 Chuck body 2a Conical part 3 Tip member 3a Slope 4 Outer shaft 4a Step 4b Core chamber 4c Groove 5 Resilient member 6 Relay shaft 7 Middle shaft 7a Groove 7b Projection 8 Lid 9 Tail 9a Rib 9b Projection 9c Hole 9d collar portion 9e reduced diameter portion 10 knob 31 deformed core 32 chuck body 32a conical portion 33 tip member 33a slope 34 outer shaft 34a step 34b core chamber 34c groove 35 resilient member 36 cylindrical body 36a cam surface 36b projection 37 relay shaft 37a Through-hole 37b Stepped portion 38 Middle shaft 38a Groove 38b Protrusion 38c Circumferential flange 39 Lid 39a Engagement portion 39b Recess 40 Tail 40a Protrusion 40b Ridge 40c Reduced diameter portion 40d Protrusion 41 Knob 71 Deformed core 72 Chuck body 72a Cone Shaped portion 73 Tip member 73a Slope 74 Outer shaft 74a Step 74b Core chamber 74c Groove 75 Resilient member 76 Sleeve 76a Groove 77 Relay shaft 77a Step 8 center shaft 78a flange 78b groove 78c projecting 79 the cylindrical body 79a protruding 79b cam surface 80 lid 80a engaging portion 80b recess 81 tail plug 81a uneven portion 81b convex portion 81c flange portion 81d reduced diameter portion 81e projections 82 pinch

Claims (3)

A core body having an irregular cross section is accommodated in a plurality of core chambers provided radially on the outer shaft, and a center shaft provided with a core body guiding hole that can face one of the core chambers is rotatable in the outer shaft. The middle shaft is urged rearward by a resilient member, and is arranged in a non-rotatable manner in front of the middle shaft, and grips and releases the core body. A multi-core room type writing instrument provided with core gripping means. The multi-core room type writing instrument according to claim 1, wherein a tip member capable of rotating relative to the outer shaft is attached to a front end portion of the outer shaft. The multi-core chamber type writing instrument according to claim 1 or 2, wherein the outer shaft is provided with a collar member having a diameter larger than that of the middle shaft, and the middle shaft is advanced, moved, and rotated by the collar member. .