JP6935212B2 - Multi-core writing tool - Google Patents

Description

The present invention relates to a multi-core writing instrument. In particular, the present invention relates to a multi-core writing instrument capable of interchangeably accommodating a plurality of cursive bodies in a barrel.

Patent Document 1 discloses a multi-core writing instrument in which an opening is provided at the rear end of the barrel so that the cursive can be inserted into the barrel and removed from the barrel through the opening. .. Further, Patent Document 1 also describes that a mechanical pencil can be used as a cursive.

Specifically, as shown in FIGS. 11 to 16, in the multi-core writing tool disclosed in Patent Document 1, the shaft cylinder 2 has a front shaft 3 made of a tapered cylinder and a rear shaft 3 after the front shaft 3. It consists of a cylindrical rear axle 4 that is attached to the end by screwing or press fitting. At the front end of the front shaft 3, a front end hole 31 through which the pen tip of the cursive 6 can protrude is formed in the axial direction. The front shaft 3 and the rear shaft 4 are made of synthetic resin (for example, polycarbonate or the like) or metal.

Two (or may be 3 to 5) elongated window holes 41 extending in the front-rear direction are provided in the rear side wall of the rear shaft 4 in the radial direction. The two window holes 41 are formed at positions symmetrical with respect to the axis.

On the inner surface of the side wall between the two window holes 41 of the rear shaft 4, a locking wall portion 43 formed of ribs extending in the front-rear direction is formed. The locking wall portion 43 can lock the rear end of the operating body 7 of the cursive body 6 with the pen tip protruding. Further, for example, as shown in FIGS. 11 to 16, it is preferable that the clip 44 is provided on the outer surface of the side wall between the two window holes 41 of the rear shaft 4.

At the rear end of the rear shaft 4, a lid 5 for opening and closing the opening 42 is rotatably provided. One end of the lid 5 is rotatably connected to the base of the clip 44 by a hinge 52. The hinge portion 52 extends in the left-right direction of the clip 44 when the clip 44 is viewed from the front with the pen tip facing downward. As a result, the lid portion 5 is rotatable in the substantially front-rear direction.

A contact wall portion 51 is formed on the front surface of the lid portion 5. The rear end of the operating body 7 connected to the rear end of the immersive cursive 6 is abutted against the contact wall portion 51. The hinge portion 52 is typically configured to be rotatably connected by a rotating shaft, but in addition to this aspect, a connecting portion having flexibility that can be bent and deformed is also adopted. obtain.

An engaging portion 53 is provided on the front surface of the other end of the lid portion 5 (specifically, for example, an engaging recess or an engaging hole portion is formed), and the rear end of the rear shaft 4 is provided with an engaging portion 53. An engaged portion 45 that can be engaged with the engaging portion 53 is provided (specifically, for example, an engaging convex portion is projected). More specifically, an inward protrusion is formed on the inner surface of the engaging portion 53 (engagement concave portion or engagement hole portion), and the outer surface of the engaged portion 45 (engagement convex portion) is locked over the inward projection. Possible extroverts can be formed.

In this case, the engaging portion 53 and the engaged portion 45 are in an engaged state with each other while the lid portion 5 closes the opening 42 (the inward protrusion and the outward protrusion are in a locked state overcoming). .. The engaged state is not released by the contact between the operating body 7 and the contact wall portion 51 of the lid portion 5 due to the rearward urging of the coil spring 8, and the lid portion 5 does not open.

Here, each cursive 6 can be a knock-type mechanical pencil. Specifically, the writing body 6 includes a lead core accommodating cylinder 61, a connecting cylinder 62 detachably attached to the front end of the lead core accommodating cylinder 61 so as to be replenishable with a lead core, and the connecting cylinder 62. The chuck body 63 provided at the front end of the above, the front end cylinder 64 which accommodates the front end portion of the connecting cylinder 62 and the chuck body 63 inside and is attached so as to be movable in the front-rear direction with respect to the connecting cylinder 62. A tightening ring 65 housed inside the front end cylinder 64 and tightening the chuck body 63, and a front end cylinder 64 interposed between the front end cylinder 64 and the connecting cylinder 62 are attached to the front of the connecting cylinder 62. It has a chuck spring 66 and a forceful chuck spring 66. The front end portion of the front end cylinder 64 constitutes the pen tip 64a of the cursive body 6.

The lead core 67 is housed in the lead core accommodating cylinder 61. When the lead core accommodating cylinder 61 is pressed forward against the front end cylinder 64 against the urging of the chuck spring 66, the connecting cylinder 62 and the chuck body 63 also advance as the lead core accommodating cylinder 61 advances. However, the chuck body 63 is separated from the tightening ring 65. Further, the lead core 67 is extended forward as the chuck body 63 advances, and the lead core 67 protrudes forward from the front end opening of the front end tubular body 64.

On the other hand, when the forward pressure of the lead core accommodating cylinder 61 against the front end cylinder 64 is released, the chuck body 63 retracts due to the urging of the chuck spring 66, and the tightening ring 65 reengages with the outer peripheral surface of the chuck body 63. Then, the tightening ring 65 re-tightens the chuck body 63 inward in the radial direction. As a result, the chuck body 63 is designed to hold the extended lead core 67 again. As a result, the protruding state of the lead core 67 from the opening of the front end cylinder 64 is maintained.

Further, an operating body 7 is attached to the rear end of each cursive 6 (that is, the rear end opening 42 of the lead core accommodating cylinder 61). Each operating body 7 has an operating portion 71, a front protruding portion 72, a rear protruding portion 73, a fitting portion 74, and a flange portion 75. The operation unit 71 is formed at the rear end of the operation body 7 and projects outward from the window hole 41 of the barrel 2. The rear protruding portion 73 is provided on the opposite side of the operating portion 71 of the operating body 7, the front protruding portion 72 is provided in front of the rear protruding portion 73, and the fitting portion 74 is provided on the front end portion of the operating body 7. It is formed and fitted into the rear end opening 42 of the lead core accommodating cylinder 61. The flange portion 75 is formed behind the fitting portion 74, and the front surface of the flange portion 75 presses the rear end of the coil spring 8, which will be described later.

Further, locking protrusions (not shown) are formed on both side surfaces of the operating body 7, and the locking protrusions can be engaged with each other on both side walls of the window hole 41. The operating body 7 is obtained by molding a synthetic resin (for example, polypropylene resin, ABS resin, polyacetal resin, etc.).

When the pen tip 64a of the cursive 6 is in an immersive state, the rear end portion of the operating body 7 attached to the cursive 6 is in a state of being abutted by the contact wall portion 51. On the other hand, when the pen tip 64a of the cursive 6 is in the protruding state, the rear end portion of the operating body 7 attached to the cursive 6 is locked to the locking wall portion 43 formed on the inner wall of the barrel 2. It is supposed to be in the state of being.

Further, the front protruding portion 72 of the operating body 7 connected to the cursive 6 in the pen tip immersion state is another protruding portion first when the operating portion 71 of the operating body 7 is slid forward. If there is a cursive 6, it comes into contact with the rear protruding portion 73 of the operating body 7 connected to the other cursive 6 to release the locked state between the operating body 7 and the locking wall portion 43, that is, , The pen tip protruding state of the other cursive 6 is released.

A cylindrical spring support 9 is provided on the inner wall of the axle cylinder 2 (that is, the inner wall of the rear shaft 4). The spring support 9 is provided with two inner holes 91 through which each cursive 6 is inserted in the axial direction. A coil spring 8 is arranged on the rear surface of the spring support 9 corresponding to each inner hole 91. The cursive 6 is loosely inserted inside each inner hole 91 and each coil spring 8, and the front surface of the flange portion 75 of the operating body 7 presses the rear end of the coil spring 8.

More specifically, on the rear surface of the spring support 9, a cylindrical holding portion that protrudes rearward is formed corresponding to each inner hole 91. Then, the outer surface of the front end portion of each coil spring 8 is press-fitted and held on the inner surface of each holding portion. As a result, when the cursive body 6 (and the operating body 7) is replaced, the coil spring 8 is prevented from falling off due to the replacement work.

Each coil spring 8 constantly urges each operating body 7 (that is, each cursive 6) to the rear. That is, each coil spring 8 maintains a compressed state (that is, a state in which the cursive 6 is urged rearward) in both the pen tip protruding state and the pen tip immersion state. As a result, rattling in the front and rear of the operating body 7 is prevented. However, each coil spring 8 is in an uncompressed state (free state) when the cursive body 6 is not inserted inside the coil spring 8 (for example, in a state where the cursive body is being replaced).

The multi-core writing tool having the above configuration operates as follows.

When the operating portion 71 of one operating body 7 is selected and slid forward along the window hole 41 against the rearward bias of the coil spring 8, the front protruding portion of the slid-operated operating body 7 is operated. If the 72 has another cursive 6 that is in the protruding state first, the rear protruding portion 73 of the operating portion 71 of the other cursive 6 is lifted outward in the radial direction. As a result, the locked state of the locking wall portion 43 of the inner wall of the barrel 2 and the operating body 7 of the other cursive 6 is released, and the other cursive 6 moves backward due to the rearward bias of the coil spring 8. That is, it is immersed in the barrel 2. At the same time as the other cursive 6 is immersed, the pen tip 64a of the cursive 6 connected to the operating body 7 slid forward is projected outward from the front end hole 31 of the barrel 2. Then, the rear end of the operating body 7 that has been slid forward is newly locked to the locking wall portion 43 of the inner wall of the barrel 2, and the pen tip protruding state is maintained.

When the operation unit 71 of the operating body 7 connected to the cursive 6 is further forwardly pressed in a state where the pen tip 64a protrudes forward from the front end hole 31 of the barrel 2, the front end cylinder 64 of the cursive is pressed. The outer surface is locked to the inner wall of the front end portion of the shaft cylinder 2, and the lead core accommodating cylinder 64, the connecting cylinder 62 and the chuck body 63 are moved forward against the urging of the chuck spring 66. Along with this, the chuck body 63 is released from the tightening of the tightening ring 65, the lead core 67 is extended forward, and the lead core 67 protrudes forward from the front end opening of the front end cylinder 64. Then, when the pressure on the operation unit 71 to the front is released, the chuck body 63 retracts due to the urging of the chuck spring 66, the tightening ring 65 reengages with the outer peripheral surface of the chuck body 63, and the tightening ring 65 is engaged. The chuck body 63 is re-tightened inward in the radial direction. As a result, the chuck body 63 holds the extended lead core 67 again. As a result, the protruding state of the lead core 67 from the front end opening (front end of the pen tip 64a) of the front end cylinder 64 is maintained.

When the cursive 6 is replaced, the operating end of the lid 5 opposite to the hinge 52 of the lid 5 is opened from the state where the lid 5 closes the opening 42 at the rear end of the barrel 2 (see FIG. 11). By pressing backward to release the engagement between the engaging portion 53 and the engaged portion 45 and rotating the lid portion 5 rearward, the opening 42 at the rear end of the barrel 2 is opened. At the same time, each operating body 7 is projected from the opening 42 to the rear outside by the rear bias of the coil spring 8 (FIG. 13). By taking out the operating body 7 from this state, the cursive body 6 connected to the operating body 7 can be taken out from the inside of the barrel 2.

Then, a new cursive 6 (and a new operating body 7) is inserted into the barrel 2 through the opening 42. Then, each operating body 7 is brought into contact with the contact wall portion 51 of the lid portion 5, and the lid portion 5 is rotated forward so as to press each operating body 7 forward, and the engaging portion 53 and the cover are covered. Engage with the locking portion and close the opening 42. Along with this, the front surface of the flange portion 75 of the new operating body 7 presses the rear end of the corresponding coil spring 8, and the cursive 6 (and operating body 7) replacement work is completed.

JP 2010-5830

The multi-core writing tools described with reference to FIGS. 11 to 16 have already been commercialized and have a good sales record. However, at the time of commercialization, the cursive body 6 has been redesigned so that the chuck spring 66 is surrounded by the chuck spring holding cylinder 166t (see FIG. 4).

Here, the lead core is accommodated inside the lead core accommodating cylinder 61 in a state where the lead core accommodating cylinder 61 and the connecting cylinder 62 are separated. That is, the lead core accommodating cylinder 61 and the connecting cylinder 62 need to be structurally smoothly separable (and recombine). Therefore, there is a slight step a between the two (see FIG. 4).

On the other hand, when the spring support 9 is commercialized, the cylindrical holding portion provided for each inner hole 91 is integrated, and as shown in FIG. 17, the entire spring support 9 is long (about 21 mm) in the axial direction. The design has been changed to a cylindrical member.

Then, the inventor of the present invention has found a problem that can be improved, although it is not a defect, while earnestly examining the points for improvement of the product. That is, when the cursive 6 is taken out from the barrel 2 in order to replace the cursive 6, the step a (0.3 mm) is the end of the inner hole 91 of the spring support 9, as shown in FIG. It is a problem that the user may be uncomfortable by being caught in the part.

The present invention has been made in view of the above findings, and an object of the present invention is a multi-core writing instrument capable of interchangeably accommodating a plurality of cursive bodies in a barrel for writing. It is to provide a multi-core writing instrument that does not cause discomfort to the user when exchanging bodies.

The present invention includes a shaft cylinder provided with an opening that opens rearward, and a plurality of writing bodies that are interchangeably housed in the shaft cylinder, and an operation unit is provided on the rear end side of each writing body. An operating body having a A locking portion that protrudes outward in the radial direction from the shaft and can lock a part of the operating body corresponding to the operating portion when a certain operating portion is slid forward. Is provided, and a plurality of coil springs for urging each of the plurality of writing bodies to the rear are provided inside the shaft cylinder, and the front end side of the plurality of coil springs is the shaft cylinder. It is supported by a spring support fixed to the spring support, and the spring support is provided with a plurality of inner holes through which the plurality of writing bodies can be inserted, and at least the shaft at the front end of each inner hole. A chamfered region is provided in a part of the region on the central axis side of the cylinder, and the chamfered region has a radius of curvature of 0.1 mm to 2 in a cross section including the central axis of the inner hole provided with the chamfered region. It is a multi-core writing tool characterized by having a curved portion in a range of 0.0 mm.

According to the present invention, since a chamfered region is provided at least in a part of the region on the central axis side of the barrel at the front end of each inner hole, the cursive is taken out from the barrel in order to replace the cursive. At that time, the occurrence of the phenomenon that the step of the cursive is caught on the front end of the inner hole can be remarkably suppressed. This eliminates concerns that it can be offensive to the user.

In particular, at least one of the cursive is a knock-type mechanical pencil. In this case, conventionally, the phenomenon that the step of the cursive is caught in the front end of the inner hole may occur from time to time.

From the viewpoint of the action and effect of the present invention, as described above, it is sufficient that the chamfered region is provided in a part of the region on the central axis side of the barrel. Specifically, for example, when a plurality of inner holes are provided at the same distance from the central axis of the barrel, only the inner region of the virtual cylindrical surface that is concentric with the barrel and passes through the central axes of the plurality of inner holes. It suffices if a chamfered area is provided (see FIG. 8). However, from the viewpoint of manufacturing (for example, from the viewpoint of manufacturing accuracy and manufacturing cost by plastic injection molding), it is preferable to provide a chamfered region on the entire circumference of the front end of each inner hole.

As a result of manufacturing and evaluation experiments of various prototypes by the present inventor, in order to effectively suppress the step of the cursive from being caught in the front end of the inner hole, the chamfered region has a radial width of 0. It is preferably provided in the range of 1 mm to 2.0 mm (preferably larger than the dimension of the step a (0.3 mm)). Then, the chamfered area is not preferable that the inclination angle in a cross section including the central axis of the bore in which the edge region is provided with a tapered portion in the range of 10 ° to 60 °.

Further, the present invention also covers only the shaft cylinder of the above-mentioned multi-core writing instrument. That is, the present invention is a shaft cylinder capable of accommodating a plurality of writing bodies provided with an opening that opens rearward and provided with an operating body having an operating portion, and the side wall of the shaft cylinder is provided in the front-rear direction. A plurality of window holes extending in the radial direction are distributed and penetrated in the radial direction, and when the plurality of writing bodies are accommodated, the operation unit of each operating body protrudes outward in the radial direction from the corresponding window hole. When one operation unit is slid forward from the state in which the plurality of writing bodies are housed, a part of the operation body corresponding to the operation unit can be locked inside the axle cylinder. A possible locking portion is provided, and a plurality of coils capable of urging each of the plurality of writing bodies rearward in a state where the plurality of writing bodies are housed inside the axle cylinder. A spring is provided, and the front end side of the plurality of coil springs is supported by a spring support fixed to the shaft cylinder, and the plurality of writing bodies can be inserted into the spring support. A plurality of inner holes are provided, and a chamfering region is provided at least in a part of the front end of each inner hole on the central axis side of the barrel, and the chamfering region is provided with the chamfering region. It is a shaft cylinder for a multi-core writing tool characterized by having a curved portion having a radius of curvature in the range of 0.1 mm to 2.0 mm in a cross section including the central axis of the inner hole.

According to the present invention, since a chamfered region is provided at least in a part of the region on the central axis side of the barrel at the front end of each inner hole, the cursive is taken out from the barrel in order to replace the cursive. At that time, the occurrence of the phenomenon that the step of the cursive is caught on the front end of the inner hole can be remarkably suppressed. This eliminates concerns that it can be offensive to the user.

It is a schematic vertical sectional view of the multi-core writing instrument in one Embodiment of this invention, and is the figure which shows the state in which all cursives are not protruding. It is a schematic vertical sectional view of the multi-core writing instrument of FIG. 1, and is the figure which shows the state which the knock type mechanical pencil protrudes. It is a schematic vertical sectional view of the multi-core writing instrument of FIG. 1, and is the figure which shows the state which takes out the knock type mechanical pencil. It is an enlarged view of the knock type mechanical pencil which is the cursive of the multi-core writing instrument of FIG. It is a perspective view seen from the front side of the spring support of the multi-core writing instrument of FIG. 6 (a) is a front view of the spring support of FIG. 5 as viewed from the front side, and FIG. 6 (b) is a vertical cross-sectional view of the spring support of FIG. It is an enlarged view of the broken line part of FIG. It is a figure which shows an example of at least a part region on the central axis side of a shaft cylinder at the front end of an inner hole. FIG. 9A is a front view of the modified example of the spring support as viewed from the front side, and FIG. 9B is a vertical cross-sectional view of the modified example of the spring support. It is a figure corresponding to FIG. 7 when the modification of the spring support of FIG. 9A and FIG. 9B is adopted. It is a vertical cross-sectional view which shows all the pen tip immersion state (non-writing state) of the conventional multi-core writing instrument. It is a vertical cross-sectional view which shows the state (writing state) that one pen tip of one of the multi-core writing instruments of FIG. 11 protrudes. It is a side view which shows the state which opened the opening of the rear end of the multi-core writing instrument of FIG. It is an enlarged vertical sectional view which shows the front end part of the cursive of FIG. 11 is an enlarged vertical cross-sectional view showing the rear end of the cursive body and the operating body of FIG. 11 is an external view showing a cursive body and an operating body which are connected to each other in FIG. 11. It is a perspective view which shows the spring support in the commercialized multi-core writing tool. It is a schematic cross-sectional view which shows how the step of a cursive is caught.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic vertical sectional view of a multi-core writing instrument 101 according to an embodiment of the present invention, showing a state in which all writing instruments do not protrude, and FIG. 2 is a diagram showing a state in which all writing instruments do not protrude. FIG. 3 is a schematic vertical sectional view of the above, showing a state in which a knock-type mechanical pencil 106 is projected, and FIG. 3 is a schematic vertical sectional view of the multi-core writing instrument 101 of FIG. 1, which is a knock-type mechanical pencil. It is a figure which shows the state which the pencil 106 is taken out. Further, FIG. 4 is an enlarged view of a knock-type mechanical pencil 106, which is one of the cursives of the multi-core writing instrument 101 of FIG.

5 is a perspective view of the spring support 109 of the multi-core writing tool 101 of FIG. 1 as viewed from the front side, and FIG. 6A is a front view of the spring support 109 of FIG. 5 as viewed from the front side. 6 (b) is a vertical cross-sectional view of the spring support 109 of FIG. Further, FIG. 7 is an enlarged view of the broken line portion of FIG.

The basic configuration of the multi-core writing instrument 101 of the present embodiment shown in FIGS. 1 to 7 will be described with reference to FIGS. 11 to 16 except for the writing body 106 and the spring support 109, which are knock-type mechanical pencils. It is substantially the same as the conventional multi-core writing instrument 1.

Specifically, in the multi-core writing tool 101 of the present embodiment, as shown in FIG. 1, the shaft cylinder 102 is screwed with a front shaft 103 made of a tapered cylindrical body and a rear end portion of the front shaft 103. Alternatively, it is composed of a cylindrical rear shaft 104 attached by press fitting. At the front end of the front shaft 103, a front end hole 131 through which the pen tip of the cursive 106 can protrude is formed in the axial direction. The front axle 103 and the rear axle 104 are made of synthetic resin (for example, polycarbonate or the like) or metal.

As shown in FIG. 2, on the rear side wall of the rear shaft 104, five elongated window holes 141 (which can be selected from 2 to 6) extending in the front-rear direction penetrate in the radial direction in the present embodiment. It is installed. The five window holes 141 are formed, for example, at equal intervals in the circumferential direction.

A release bar 143 extending in the front-rear direction extends in a region on the inner axis side of the five window holes 141 of the rear shaft 104. The front end of the release bar 143 is supported by a spring support 109, which will be described later. On the other hand, a locking wall portion 143a extending in the front-rear direction is formed on the inner surface of the side wall between the five window holes 141 of the rear shaft 104, and the locking wall portion 143a has a pen tip protruding from the locking wall portion 143a. The rear end of the operating body 107 of the cursive 106 can be locked. Then, when the rear end of the operating body 107 of the cursive 106 with the pen tip protruding is locked to the locking wall portion 143a, the other writing body 106, 206 is projected instead. When the operating body 107 of the cursive 106, 206 is moved forward, the operating body 107 of the other cursive 106, 206 presses the release bar 143 outward in the radial direction, and the pressed release bar 143 is pressed. Presses the rear end of the operating body 107 locked to the locking wall portion 143a radially outward to release the locked state. In addition, a clip 144 is provided at one place on the outer surface of the side wall between the five window holes 141 of the rear shaft 104.

As shown in FIG. 3, a lid 105 for opening and closing the opening 142 is rotatably provided at the rear end of the rear shaft 104. One end of the lid 105 can be rotatably connected to, for example, the base of the clip 144 by a hinge. The hinge portion can be extended in the left-right direction of the clip 144 when the clip 144 is viewed from the front with the pen tip facing downward, for example. In this case, the lid 105 may be rotatable in the substantially front-rear direction.

A contact wall portion 151 is formed on the front surface of the lid portion 105. The rear end of the operating body 107 connected to the rear end of the immersive cursive 106 is abutted against the contact wall portion 151 (see FIG. 1). As the hinge portion, a configuration in which the hinge portion is rotatably connected by a rotating shaft can be typically adopted, but in addition to this embodiment, a connecting portion having flexibility that can be bent and deformed can also be adopted. ..

Then, for example, an engaging portion is provided on the front surface of the other end of the lid 105 (for example, an engaging recess or an engaging hole), and the rear end of the rear shaft 104 engages with the engaging portion. Possible engaged portions may be provided (eg, engaging protrusions). More specifically, an inward protrusion may be formed on the inner surface of the engaging portion (engagement concave portion or engagement hole portion), and the inward projection can be overcome and locked on the outer surface of the engaged portion (engagement convex portion). Extraverted protrusions can be formed.

In this case, the engaged portion and the engaged portion are in an engaged state with each other while the lid portion 105 closes the opening 142 (the inward protrusion and the outward protrusion are in a locked state overcoming). The engaged state is not released by the contact between the operating body 107 and the contact wall portion 151 of the lid portion 105 due to the rearward urging of the coil spring 108, and the lid portion 105 does not open.

Here, as shown in FIGS. 1 to 3, in the present embodiment, one cursive 106 is a knock-type mechanical pencil, and the other cursive 206 is a ballpoint pen.

As shown in FIG. 4, the writing body 106, which is a knock-type sharp pencil, has a lead core accommodating cylinder 161 and a connecting cylinder detachably attached to the front end of the lead core accommodating cylinder 161 so that the lead core can be replenished. The body 162, the chuck body provided at the front end of the connecting cylinder 162 (see FIG. 14), the front end of the connecting cylinder 62 and the chuck body are housed inside, and the body 162 is arranged in the front-rear direction with respect to the connecting cylinder 162. It is interposed between the front end cylinder 164 that is movably attached, the tightening ring that is housed inside the front end cylinder 164 and tightens the chuck body (see FIG. 14), and the front end cylinder 164 and the connecting cylinder 162. It has a chuck spring (see FIG. 14) that urges the front end cylinder 164 forward with respect to the connecting cylinder 162. The chuck spring is surrounded by a chuck spring holding cylinder 166t, and the front end portion of the front end cylinder body 164 constitutes the pen tip 164a of the cursive body 106.

The internal configuration of the chuck spring holding cylinder 166t, that is, the chuck spring (66) and the internal configuration of the front end cylinder body 164, that is, the chuck body (63) and the tightening ring (65) are not visible in FIG. It is substantially the same as the conventional configuration shown in FIG.

The lead core is housed in the lead core housing cylinder 161. When the lead core accommodating cylinder 161 is pressed forward against the front end cylinder 164 against the urging of the chuck spring, the connecting cylinder 162 and the chuck body are also advanced as the lead core accommodating cylinder 161 advances. The chuck body is separated from the tightening ring. Further, the lead core is extended forward as the chuck body advances, and the lead core protrudes forward from the front end opening of the front end cylinder 164.

On the other hand, when the forward pressure of the lead core accommodating cylinder 161 on the front end cylinder 164 is released, the chuck body retracts due to the urging of the chuck spring, the tightening ring reengages with the outer peripheral surface of the chuck body, and the tightening ring. Is designed to re-tighten the chuck body inward in the radial direction. As a result, the chuck body is designed to hold the drawn lead core again. As a result, the protruding state of the lead core from the opening of the front end cylinder 164 is maintained.

Further, an operating body 107 is attached to the rear ends of the cursive bodies 106 and 206 (that is, the rear end opening 142 of the lead core accommodating cylinder 161 and the rear end opening of the ink accommodating cylinder). Each operating body 107 has an operating portion 171, a front protruding portion 172, a rear protruding portion 173, a fitting portion 174, and a flange portion 175, particularly as shown in FIGS. 2 and 3. ing. The operation unit 171 is formed at the rear end of the operation body 107, and projects outward from the window hole 141 of the barrel 102. The rear protruding portion 173 is provided on the opposite side of the operating portion 171 of the operating body 107, the front protruding portion 172 is provided in front of the rear protruding portion 173, and the fitting portion 174 is provided on the front end portion of the operating body 107. It is formed and fitted into the rear end opening 142 of the lead core accommodating cylinder 161 or the rear end opening of the ink accommodating cylinder 161. The collar portion 175 is formed behind the fitting portion 174, and the front surface of the collar portion 175 presses the rear end of the coil spring 108, which will be described later.

Further, locking protrusions (not shown) are formed on both side surfaces of the operating body 107, and the locking protrusions can be engaged with each other on both side walls of the window hole 141. The operating body 107 is obtained by molding a synthetic resin (for example, polypropylene resin, ABS resin, polyacetal resin, etc.).

When the pen tip 164a of the cursive 106 is in an immersive state, the rear end portion of the operating body 107 attached to the cursive 106 is in a state of being abutted by the contact wall portion 151 ( (See FIG. 1). On the other hand, when the pen tip 164a of the cursive 106 is in the protruding state, the rear end of the operating body 107 attached to the cursive 106 is locked to the locking wall portion 143a formed inside the barrel 102. (See Fig. 2).

Further, the front protruding portion 172 of the operating body 107 connected to the cursive bodies 106 and 206 in the pen tip immersion state slides the release bar 143 in the radial direction when the operating unit 171 of the operating body 107 is slid forward. Press outward. At this time, if there are other cursive bodies 106, 206 that are in the protruding state first, the release bar 143 pressed outward in the radial direction is connected to the other cursive bodies 106, 206 of the operating body 107. The rear protruding portion 173 is pressed in this direction to release the locked state between the rear end of the operating body 107 and the locking wall portion 143a, that is, the pen tip protruding state of the other cursive bodies 106 and 206 is released. It is designed to be released.

On the other hand, a cylindrical spring support 109 is provided inside the axle tube 102 (inside the rear axle 104). The spring support 109 is provided with five inner holes 191 through which the cursives 106 and 206 are inserted in the axial direction. A coil spring 108 is arranged on the rear surface side of the spring support 109 corresponding to each inner hole 191. The cursives 106 and 206 are loosely inserted into the inner holes 191 and the coil springs 108, and the front surface of the flange 175 of the operating body 107 presses the rear end of the coil springs 108.

More specifically, a cylindrical recess is formed on the rear end surface of the spring support 109 corresponding to each inner hole 191. Then, the outer surface of the front end portion of each coil spring 108 is press-fitted and held in each recess. As a result, when the cursives 106 and 206 (and the operating body 107) are replaced, the coil spring 108 is prevented from falling off due to the replacement work.

Each coil spring 108 constantly urges each operating body 107 (ie, each cursive 106, 206) backwards. That is, each coil spring 108 maintains a compressed state (that is, a state in which the cursives 106 and 206 are urged rearward) in both the pen tip protruding state and the pen tip immersion state. As a result, rattling in the front and rear of the operating body 107 is prevented. However, each coil spring 108 is in an uncompressed state (free state) when the cursive bodies 106 and 206 are not inserted therein (for example, a state in which the cursive body is being replaced).

Further, in the spring support 109 of the present embodiment, as shown in FIGS. 5, 6 (a) and 6 (b), a chamfered region 193 is provided on the entire circumference of the front end of each inner hole 191. ing. The chamfered region 193 has a radial width b in the range of 0.1 mm to 2.0 mm, and an inclination angle θ in a cross section including the central axis of the inner hole 191 (see FIG. 6B) is 10 ° to 60 °. In this embodiment, b = 0.4 mm and θ = 45 ° are adopted.

The multi-core writing tool 101 having the above configuration operates as follows.

When the operating unit 171 of one operating body 107 is selected and slid forward along the window hole 141 against the rearward bias of the coil spring 108, the front protruding portion of the slid-operated operating body 107 is operated. 172 presses the release bar 143 radially outward. At this time, if there are other cursive bodies 106, 206 that are in the protruding state first, the release bar 143 pressed outward in the radial direction corresponds to the rear protruding portion 173 of the other cursive bodies 106, 206. By pressing in the direction, the locked state between the rear end of the operating body 107 and the locking wall portion 143a is released. As a result, the other cursive bodies 106 and 206 are moved rearward by the rearward bias of the coil spring 108, that is, they are immersed in the barrel 102. Simultaneously with the immersion of the other cursive bodies 106 and 206, the pen tip of the cursive bodies 106 and 206 connected to the operating body 107 slid forward is projected outward from the front end hole 131 of the barrel 102. Then, the rear end of the operating body 107 that has been slid forward is newly locked to the locking wall portion 143a inside the barrel 102, and the pen tip protruding state is maintained.

With the pen tip 164a of the cursive 106 (knock-type mechanical pencil) protruding forward from the front end hole 131 of the barrel 102, the operation unit 171 of the operating body 107 connected to the cursive 106 is pressed further forward. Then, the outer surface of the front end cylinder 164 of the cursive 106 is locked to the inner wall of the front end portion of the shaft cylinder 102, and the lead core accommodating cylinder 161, the connecting cylinder 162, and the chuck body move forward against the urging of the chuck spring. Moved to. Along with this, the chuck body is released from the tightening of the tightening ring, the lead core is extended forward, and the lead core is projected forward from the front end opening of the front end cylinder 164. Then, when the forward pressing of the operation unit 171 is released, the chuck body retracts due to the urging of the chuck spring, the tightening ring reengages with the outer peripheral surface of the chuck body, and the tightening ring radially engages the chuck body. Tighten inward again. As a result, the chuck body holds the drawn lead core again. As a result, the protruding state of the lead core from the front end opening (front end of the pen tip 164a) of the front end cylinder 164 is maintained.

When the cursive 106 is replaced, the lid 105 closes the opening 142 at the rear end of the barrel 102 (see FIG. 1), and the operating end opposite to the hinge portion of the lid 105 is rearward. The engagement portion and the engaged portion are disengaged by pressing the lid portion 105, and the lid portion 105 is rotated rearward to open the opening portion 142 at the rear end of the barrel 102. At the same time, each operating body 107 is projected from the opening 142 to the rear outside by the rear bias of the coil spring 108. By taking out the operating body 107 from this state (see FIG. 3), the cursive 106 in the connected state with the operating body 107 can be taken out from the inside of the shaft cylinder 102.

Here, in the case of the conventional spring support 9, as shown in FIG. 18, the step a of the cursive 106 is caught by the end of the inner hole 91 of the spring support 9, and in the work of taking out the cursive 106. There is a problem that it may cause discomfort to the user. On the other hand, according to the spring support 109 of the present embodiment, the cursive 106 is provided as shown in FIG. 7 because the chamfered region 193 is provided on the entire circumference of the front end of each inner hole 191. When the cursive 106 is taken out from the barrel 102 for replacement, the occurrence of an event that the step a of the cursive 106 is caught in the front end of the inner hole 191 can be remarkably suppressed (the taking out of the cursive 106). Work will be smooth).

Then, a new cursive 106 (and a new operating body 107) is inserted into the barrel 102 through the opening 142. Then, each operating body 107 is brought into contact with the contact wall portion 151 of the lid portion 105, and the lid portion 105 is rotated forward so as to press each operating body 107 forward, and is engaged with the engaging portion. Engage with the stop and close the opening 142. Along with this, the front surface of the flange portion 175 of the new operating body 107 presses the rear end of the corresponding coil spring 108, and the cursive 106 (and the operating body 107) replacement work is completed.

As described above, according to the multi-core cursive 101 of the present embodiment, since the chamfered area 193 is provided on the entire circumference of the front end of each inner hole 191, the cursive 106 is replaced with the cursive 106. It is possible to remarkably suppress the occurrence of an event in which the step a of the cursive 106 is caught in the front end of the inner hole 191 when it is taken out from the inside of the barrel 102. This eliminates concerns that it can be offensive to the user.

In the multi-core writing tool 101 of the above embodiment, the chamfered area 193 is provided on the entire circumference of the front end of each inner hole 191. However, from the viewpoint of the effect of the present invention, the chamfered area 193 is a shaft cylinder. It suffices if it is provided in a part of the area on the central axis side of 102. Specifically, for example, when a plurality of inner holes 191 are provided at equal distances from the central axis of the shaft cylinder 102, as shown in the hatched region of FIG. 8, the plurality of inner holes 191 are concentric with the shaft cylinder 102. It suffices if the chamfered area is provided only in the inner area of the virtual cylindrical surface passing through the central axis of. However, from the viewpoint of manufacturing (for example, from the viewpoint of manufacturing accuracy and manufacturing cost by plastic injection molding), it is preferable to provide the chamfered region 193 on the entire circumference of the front end of each inner hole 191.

Further, the chamfered region 193 of the embodiment has a radial width b of 0.4 mm and an inclination angle θ of 45 ° in a cross section including the central axis of the inner hole 191 (see FIG. 6B). , The chamfered area may be formed by a curved surface.

For example, FIG. 9A is a front view of a modified example of the spring support as viewed from the front side, and FIG. 9B is a vertical cross-sectional view of the modified example of the spring support. As shown in FIGS. 9 (a) and 9 (b), the chamfered region 195 has a radial width b in the range of 0.1 mm to 2.0 mm and has a cross section including the central axis of the inner hole 191 (FIG. 9 (b)) may have a curved surface portion having a radius of curvature R in the range of 0.1 mm to 2.0 mm (in the example of FIG. 9 (b), b = 0.35 mm, R = 0. It is 35 mm.

FIG. 10 is a diagram corresponding to FIG. 7 when a modified example of the spring support of FIGS. 9 (a) and 9 (b) is adopted. Also in this case, as shown in FIG. 10, when the cursive 106 is taken out from the barrel 102 in order to replace the cursive 106, the step a of the cursive 106 is caught in the front end of the inner hole 191. Can be remarkably suppressed (the work of taking out the cursive 106 becomes smooth).

101 Multi-core writing tool (one embodiment of the present invention)
102 Axle cylinder 103 Front shaft 131 Front end hole 104 Rear shaft 141 Window hole 142 Opening 143 Release bar 143a Locking wall 144 Clip 105 Lid 151 Contact wall 106 Cursive (knock-type mechanical pencil)
206 Cursive (ballpoint pen)
161 Lead core accommodating cylinder 162 Connecting cylinder 164 Front end cylinder 164a Pen tip 107 Operation body 171 Operation part 172 Front side protrusion 173 Rear side protrusion 174 Fitting part 175 Fitting part 108 Coil spring 109 Spring support 191 Inner hole 193 Chamfering Area (Chamfered conical surface)
195 Chamfered area (curved surface)
1 Multi-core writing tool (conventional technology)
2 Axle cylinder 3 Front shaft 31 Front end hole 4 Rear shaft 41 Window hole 42 Opening 43 Locking wall 44 Clip 45 Engagement 5 Lid 51 Contact wall 52 Hinge 53 Engagement 6 Writing body 61 Lead Core accommodation cylinder 62 Connecting cylinder 63 Chuck body 64 Front end cylinder 64a Pen tip 65 Tightening ring 66 Chuck spring 67 Lead core 7 Operation body 71 Operation part 72 Front side protrusion 73 Rear side protrusion 74 Fitting part 75 Fitting part 8 Coil Spring 9 Spring support 91 Inner hole

Claims (9)

A barrel with an opening that opens to the rear,
A plurality of cursive cursives interchangeably housed in the barrel,
With
An operating body having an operating unit is provided on the rear end side of each cursive.
A plurality of window holes extending in the front-rear direction are distributed and penetrated in the side wall of the barrel in the radial direction.
The operation part of each operating body projects radially outward from the corresponding window hole.
Inside the barrel, a locking portion is provided that can lock a part of the operating body corresponding to the operating portion when the operating portion is slid forward.
Inside the barrel, a plurality of coil springs for urging each of the plurality of cursive bodies to the rear are provided.
The front end side of the plurality of coil springs is supported by a spring support fixed to the axle cylinder.
The spring support is provided with a plurality of inner holes through which the plurality of cursives can be inserted.
A chamfered region is provided at least in a part of the front end of each inner hole on the central axis side of the barrel .
The chamfered region has a multi-core portion having a curved surface portion having a radius of curvature in the range of 0.1 mm to 2.0 mm in a cross section including the central axis of the inner hole provided with the chamfered region. Writing tool. The multi-core writing instrument according to claim 1, wherein at least one of the cursives is a knock-type mechanical pencil. The multi-core writing tool according to claim 1 or 2, wherein the chamfered area is provided on the entire circumference of the front end of each inner hole. The multi-core writing tool according to any one of claims 1 to 3, wherein the chamfered region is provided in a radial width range of 0.1 mm to 2.0 mm. Any of claims 1 to 4, wherein the chamfered region has a tapered portion having an inclination angle in the range of 10 ° to 60 ° in a cross section including the central axis of the inner hole provided with the chamfered region. Multi-core writing tool described in. A shaft cylinder capable of accommodating a plurality of cursive bodies provided with an opening that opens rearward and provided with an operating body having an operating unit.
A plurality of window holes extending in the front-rear direction are distributed and penetrated in the side wall of the barrel in the radial direction, and when the plurality of cursive bodies are accommodated, the operation unit of each operating body is provided from the corresponding window hole. It is designed to protrude outward in the radial direction,
Inside the barrel, a part of the operating body corresponding to the operating unit can be locked when one operating unit is slid forward from the state in which the plurality of cursive bodies are housed. There is a stop,
Inside the barrel, a plurality of coil springs capable of urging each of the plurality of cursive bodies to the rear while the plurality of cursive bodies are housed are provided.
The front end side of the plurality of coil springs is supported by a spring support fixed to the axle cylinder.
The spring support is provided with a plurality of inner holes through which the plurality of cursives can be inserted.
A chamfered region is provided at least in a part of the front end of each inner hole on the central axis side of the barrel .
The chamfered region has a multi-core portion having a curved surface portion having a radius of curvature in the range of 0.1 mm to 2.0 mm in a cross section including the central axis of the inner hole provided with the chamfered region. Shaft tube for writing tools. The shaft cylinder of the multi-core writing instrument according to claim 6 , wherein the chamfered region is provided on the entire circumference of the front end of each inner hole. The shaft cylinder of the multi-core writing tool according to claim 6 or 7 , wherein the chamfered region is provided in a radial width range of 0.1 mm to 2.0 mm. Any of claims 6 to 8 , wherein the chamfered region has a tapered portion having an inclination angle in the range of 10 ° to 60 ° in a cross section including the central axis of the inner hole provided with the chamfered region. The shaft cylinder of the multi-core writing tool described in.

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