JP2012228812A - Writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a drawing line from becoming blurred even when writing fast by securing the air circulation with the external world by a refill holding member mounted in a shaft tube, in the writing utensil not holding the refill by the shaft tube itself.SOLUTION: In the writing utensil 10 in which the refill 60 is accommodated in the shaft tube 15, and a leading shaft 40 made of the synthetic resin is fitted to the tip of the shaft tube 15, thick walled parts 42 are provided radially distributed equally to a plurality of locations on an inner circumferential surface of the leading shaft 40. While the thick walled part 42 holds the refill 60 by contacting with the periphery, and the circulation of the air of the external world and the inside of the shaft tube 15 is allowed by the gap 43 between the thick walled parts 42.

Description

  The present invention relates to a writing instrument that does not hold a refill in itself but that includes a member for instructing the refill, and particularly relates to a writing instrument that is made of wood.

  2. Description of the Related Art Conventionally, shafts of writing instruments that contain refills, such as ballpoint pens, are mainly made of plastic resin or metal with little dimensional variation during processing and little dimensional change due to temperature and humidity. However, there are cases where wood is used for the writing tube as a warm material that takes advantage of the natural texture. However, timber is not uniform in a strict sense, so when a shaft tube is formed with this, the dimensions change depending on the storage state after processing (for example, temperature and humidity), and further, distortion, warping and twisting after processing. Such deformation can also occur. When the shaft cylinder is formed of a material whose change in dimensions is unavoidable, when the refill is accommodated in the shaft cylinder and is held, the shape of the holding position of the refill varies depending on the product due to the change in dimensions. As a result, the refill may become loose when writing. Such rattling gives a user discomfort during writing.

In this way, the refill is press-fitted for the purpose of preventing the change in size and rattling caused by the change while forming the shaft of the writing instrument with a material that is likely to change in size due to the environment such as wood. Alternatively, the member to be fitted may be formed of a material such as plastic resin or metal that is difficult to change in dimensions, and this may be attached to the shaft tube.
As such an example, as disclosed in Patent Document 1 below, a technique is disclosed in which an adapter is inserted into the tip of the shaft tube, thereby bringing the tip of the refill into close contact, thereby preventing rattling.

Japanese Utility Model Publication 4-53997

When the refill is held by press-fitting or fitting into the member in this way, the portion where the refill is held is in close contact with or close to the member, so that it is difficult to introduce air into the shaft tube. Therefore, when writing is made faster, the introduction of air that supplements the amount of ink consumed cannot catch up, and ink may not reach the tip of the pen sufficiently, and the drawn line may be drawn. For example, in the invention described in Patent Document 1, since the air flow path is small between the inside and the outside from the shaft tube on the front shaft side, the drawn line becomes noticeable particularly when writing is performed quickly. .
Therefore, the present invention, in a writing instrument that does not hold a refill by the shaft cylinder itself, ensures air circulation with the outside by the refill holding member attached to the shaft cylinder, and prevents the drawn lines from curling even when the writing speed is increased. Is an issue.

In view of the above-described problems, the present invention accommodates the refill 60 in the shaft cylinder 15,
A writing instrument 10 in which a tip 40 made of synthetic resin is fitted to the tip of the shaft cylinder 15,
A thick portion 42 is provided radially at a plurality of locations on the inner peripheral surface of the front shaft 40, and the thick portion 42 contacts and holds the outer periphery of the refill 60, and the thick portion Air is allowed to flow between the outside and the inside of the shaft cylinder 15 by the gap 43 between the two.
In the present invention, in the writing instrument 10, the direction in which the writing tip is located is defined as “tip”, and the opposite direction is defined as “rear end”.
The shaft cylinder 15 is a member formed in a cylindrical shape, and accommodates the refill 60 in its internal space. In the present invention, the shaft cylinder 15 does not directly contact and hold the refill 60. The material of the shaft cylinder 15 is not particularly limited, but it is not directly involved in the holding to the refill 60, and can therefore be formed of a material such as wood that can be somewhat deformed after manufacture.

The front shaft 40 has a tapered shape toward the front end, and the front end and the rear end are open. The front shaft 40 is formed of synthetic resin, and can be formed by injection molding using two or more split molds into which core pins for forming an internal space are inserted.
The front shaft 40 is connected to the distal end portion of the shaft cylinder 15 at the rear end portion. The front shaft 40 may be directly connected to the shaft tube 15, or a joint member may be attached to the tip of the shaft tube 15, and the front shaft 40 may be attached to the joint member. On the other hand, the writing tip of the refill 60 accommodated in the shaft cylinder 15 protrudes from the tip of the tip shaft 40.
As described above, the thick portions 42 are radially arranged at a plurality of locations on the inner peripheral surface of the front shaft 40. The thick portion 42 is a portion that contacts and holds the tip portion of the refill 60.

On the other hand, the portion where the thick portion 42 is not formed, that is, the portion corresponding to the gap 43 between the thick portions 42 does not come into contact with the refill 60 even when the refill 60 is held by the front shaft 40. Therefore, air can be circulated into the shaft cylinder 15 from the inside.
With the above configuration, even if the ink in the refill 60 is consumed by writing, air corresponding to the volume is quickly introduced into the shaft cylinder 15 from the gap 43. As a result, it is possible to prevent the strokes from being drawn even when writing in speed.
It is preferable that a tail plug 50 is fixed to the rear end of the shaft cylinder 15, and the rear end of the refill 60 is held in contact with the tail plug 50. The tail plug 50 can also be formed by injection molding of a synthetic resin, like the front shaft 40. Further, it is desirable to form a thick portion 42 similar to the front shaft 40, thereby holding the rear end of the refill 60.

  Further, an air replacement hole 45 may be formed in the side surface portion of the front shaft 40. The air replacement hole 45 is preferably formed so as to avoid the portion where the thick portion 42 is provided. The air replacement hole 45 enables air to flow into the shaft cylinder 15 more quickly.

  Since the present invention is configured as described above, even if the shaft cylinder is formed of a material that is likely to be deformed due to environmental factors after molding, such as wood, or due to environmental factors after molding, the shaft cylinder itself However, since it does not directly relate to the holding of the refill, the molding accuracy of the shaft tube does not need to be increased so much. Further, since the members involved in holding the refill are molded from synthetic resin, high molding accuracy can be easily secured, and the refill can be reliably held by the thick portion formed thereby. In addition, since the gap between the thick portions is sufficiently secured, rapid air circulation through the gap is possible. Further, air flow is possible without providing vent holes on the front shaft surface or tail plug as in the prior art, and the appearance is not impaired. As described above, even if the refill is not in direct contact with the shaft tube, it is possible to prevent the refill from rattling at the time of writing and to obtain a comfortable writing line that does not drown even if the writing speed is increased. .

The writing instrument according to the first embodiment of the present invention is shown in a side view (A), a bottom view (B), a plan view (C) and a side sectional view (D), with the cap attached to the tip. A state where the cap is attached to the rear end is shown in a side sectional view (E). The cap used with the writing instrument which concerns on 1st Embodiment in this invention is shown with side sectional drawing (A), bottom view (B), and top view (C). The front shaft used in the writing instrument according to the first embodiment of the present invention is a front view (A), a bottom view (B), a front oblique partial sectional view (C), and a side sectional view (D). Show. Sectional view taken along the line II (A), plan view (B), partial front sectional view (C), and (A) of the tail plug used in the writing instrument according to the first embodiment of the present invention This is indicated by (D). II-II cross-sectional view (D) in front view (A), bottom view (B), front cross-sectional view (C), and (C) of the front shaft used in the writing instrument according to the second embodiment of the present invention It shows with. It is side surface sectional drawing which shows the shaping | molding state of the front axis | shaft used with the writing instrument which concerns on 2nd Embodiment in this invention in the state before injection (A) and after injection (B) of resin. However, in (B), in order to clearly show the injection molded product, the hatching of the mold is omitted.

Embodiments of the present invention will be described with reference to the drawings.
(1) 1st Embodiment As shown in FIG. 1, the writing instrument 10 which concerns on the 1st Embodiment of this invention is formed as a ball-point pen. FIG. 1A shows a state in which a cap 20 is attached to the tip of the shaft cylinder 15. A tail plug 50 is attached to the rear end of the shaft cylinder 15 (FIGS. 1A and 1C). A clip 21 is formed on the cap 20, and a vent hole 22 is provided on the bottom surface of the cap 20 to secure an airway in case of accidental ingestion (FIG. 1 (B)). The cap 20 is attached to the front end of the shaft tube 15 as shown in FIGS. 1A and 1D when not writing, and is attached to the rear end of the shaft tube 15 as shown in FIG. 1E when writing. Is possible. The cap 20 is formed by injection molding of hard plastic such as polypropylene, ABS, or polycarbonate.

  As shown in FIG. 1D, the shaft cylinder 15 is formed by cutting a wooden member into a cylindrical shape. Inside, a refill 60 with a ballpoint pen tip 62 attached at the tip is accommodated via a tip joint 61. The inner diameter of the shaft cylinder 15 is slightly larger than the outer diameter of the refill 60, and there is no place where the shaft cylinder 15 and the refill 60 are in direct contact. A small-diameter portion 51 of the tail plug 50 is inserted into the rear end of the shaft tube 15 and bonded to the inner surface of the shaft tube 15 with an adhesive. The rear end of the refill 60 is inserted and held at the front end portion of the tail plug 50. Further, the outer diameter of the large diameter portion 52 located at the rear end of the tail plug 50 is substantially the same as the outer diameter of the shaft tube 15. The tail plug 50 is formed by injection molding of a hard plastic such as polypropylene, ABS, or polycarbonate having a good compatibility with the adhesive.

On the other hand, a small-diameter portion 31 of a shaft joint 30 made of metal such as brass, brass, or aluminum is inserted at the tip of the shaft cylinder 15, and this is also bonded to the inner surface of the shaft cylinder 15 with an adhesive. The large-diameter portion 32 of the shaft coupling 30 is exposed from the tip of the shaft tube 15, and a male screw 33 is formed on the outer peripheral surface (FIGS. 1D and 1E).
Further, a tip shaft 40 having a rear half portion 46 that is substantially the same as the outer diameter of the shaft barrel 15 and a front half portion 41 that decreases in a taper shape toward the tip is mounted on the tip of the shaft barrel 15. The front end and the rear end of the front shaft 40 are both open. Among them, a female screw 47 is formed on the inner peripheral surface of the rear end portion (see FIGS. 3C and 3D), and is screwed with the male screw 33 of the shaft coupling 30. Further, a ball-point pen tip 62 at the tip of the refill 60 protrudes from the tip portion (FIGS. 1D and 1E). The front shaft 40 is formed by injection molding of hard plastic such as polypropylene, ABS, or polycarbonate.

  The structure of the cap 20 will be further described with reference to FIG. The cap 20 has a substantially cylindrical shape with a bottom at the tip and an open rear end (FIG. 2A). Further, the above-described vent hole 22 is provided at three positions at the tip (FIGS. 2A and 2B). From the vicinity of the front end edge of the cap 20, a clip 21 extending in the rear end direction is formed (FIGS. 2A and 2C). On the open end side of the cap 20, there are provided two rows of thick portions formed as eight undercuts that are equally distributed radially. Among these, the front end side row is a front end for engaging with a front end side locking protrusion 44 (see FIG. 3) provided on the outer periphery in the vicinity of the boundary between the front half portion 41 and the rear half portion 46 of the front shaft 40. It is formed as a side locking portion 23. Further, the rear end side row is a rear end side engaging member for engaging with a rear end side engaging protrusion 54 (see FIG. 4) provided on the outer periphery near the front end edge of the large diameter portion 52 of the tail plug 50. It is formed as a stop 24.

  The structure of the front shaft 40 will be further described with reference to FIG. As described above, the front shaft 40 includes a rear half portion 46 having an outer diameter substantially the same as the outer diameter of the shaft tube 15, and a front half portion 41 that is tapered toward the tip. At the boundary portion between the rear half portion 46 and the front half portion 41, a front end side locking protrusion 44, which is a circumferential protrusion that the front end side locking portion 23 of the cap 20 is locked, is provided (FIG. 3). (A) to (D)). A female screw 47 is formed on the inner periphery of the rear half portion 46 (FIGS. 3C and 3D) and, as described above, is screwed into the male screw 33 of the shaft coupling 30 bonded to the shaft tube 15. It has become. On the distal end side of the distal end side locking projection 44, air replacement holes 45 are provided at two locations facing each other (FIGS. 3C and 3D). Further, four thick radial portions 42 formed as undercuts are equally arranged near the tip of the inner periphery of the front half portion 41 (FIGS. 3B and 3D). The thick portion 42 holds the outer periphery of the ballpoint pen tip 62 of the refill 60 at four points (see FIGS. 1D and 1E). Further, the front end side ribs 48 are further equally distributed radially at four positions on the inner circumference of the front half portion 41 (FIGS. 3B and 3D). A portion of the tip joint 61 of the refill 60 is press-fitted into the tip side rib 48. Therefore, the refill 60 is also held at the tip side rib 48 portion.

  The structure of the tail plug 50 will be further described with reference to FIG. At the rear end of the tail plug 50, the large-diameter portion 52 surrounds the outside of the small-diameter portion 51, and these are connected by the rear-end surface 53 (FIGS. 4A and 4B). The space portion 55 (FIGS. 3A and 3C) between the small diameter portion 51 and the large diameter portion 52 is excessively bonded when the adhesive is applied to the small diameter portion 51 and bonded to the shaft tube 15. It is provided for the purpose of containing the agent and for the purpose of preventing sinking of the large diameter portion 52 during injection molding. Further, as described above, a rear end side locking protrusion 54, which is a circumferential protrusion that the rear end side locking portion 24 of the cap 20 is locked, is provided on the outer periphery on the front end side of the large diameter portion 52. (FIGS. 3A and 3C). The inner diameter of the inner space of the tail plug 50 is relatively large on the front end side and relatively small on the rear end side. And the level | step-difference part from which this internal diameter differs is the rear-end receiving part 56 with which the rear end of the refill 60 abuts (FIG. 3 (A)). Further, six rear end ribs 57 extending in the front-rear direction are radially arranged in the inner space on the front end side (FIGS. 3A and 3D). A rear end of the refill 60 is press-fitted into the rear end side rib 57. Therefore, the refill 60 is also held in the rear end side rib 57 portion.

The writing instrument 10 of the present embodiment is assembled as follows.
First, an adhesive is applied to the outside of the small-diameter portion 51 of the tail plug 50, and in this state, it is inserted into the rear end of the shaft tube 15 and adhered. In addition, an adhesive is applied to the outside of the small diameter portion 30 of the shaft coupling 30, and in this state, the adhesive is inserted into the tip of the shaft tube 15 and bonded. Then, the rear end of the refill 60 is inserted from the front end of the shaft coupling 30 exposed from the front end of the shaft tube 15, and is brought into contact with the rear end receiving portion 56 of the tail plug 50. In this state, the rear end of the refill 60 is press-fitted into a space surrounded by the six rear end side ribs 57 and is held by these rear end side ribs 57. Then, the female screw 47 on the inner surface of the front shaft 40 is screwed into the male screw 33 of the large-diameter portion 32 of the shaft coupling 30, and the front shaft 40 is screwed to the shaft coupling 30. In this state, the tip end side ribs 48 of the tip shaft 40 hold the tip joint 61, and the thick portion 42 near the tip holds the ballpoint pen tip 62. When the cap 20 is attached, the writing instrument 10 shown in FIG. 1 is completed.

In this state, the refill 60 is not in contact with the shaft cylinder 15 itself. Then, air can flow between the outside world and the inside of the shaft cylinder 15 through an air replacement hole 45 provided in the front shaft 40. In addition, air can be circulated from the outside through the gap 43 (see FIG. 3B) between the thick portions 42.
(2) Second Embodiment In the second embodiment of the present invention, the second embodiment is the same as the first embodiment except that the front shaft 40 has a shape as shown in FIG.
The front shaft 40 includes a rear half portion 46 having an outer diameter substantially the same as the outer diameter of the shaft tube 15, and a front half portion 41 that decreases in a taper shape toward the tip. At the boundary portion between the rear half portion 46 and the front half portion 41, a distal end side locking protrusion 44, which is a circumferential protrusion that the distal end side locking portion 23 of the cap 20 is locked, is provided (FIG. 4). (A) to (D)). A female screw 47 is formed on the inner periphery of the rear half portion 46 (FIG. 4C), and a male screw 33 of the shaft coupling 30 bonded to the shaft cylinder 15 (see FIGS. 1D and 1E). It is designed to be screwed together. In addition, six thick portions 42 formed as undercuts are radially arranged near the tip of the inner periphery of the front half portion 41 (FIGS. 3B, 3C, and 3D). The thick portion 42 is formed in a projection shape with a clear edge compared to that of the first embodiment, and the gap 43 is also clearer. This gap 43 sufficiently fulfills the role of the air replacement hole 45 in the first embodiment. The thick part 42 holds the outer periphery of the ballpoint pen tip 62 of the refill 60 (see FIGS. 1D and 1E) at six points. In addition, four front end side ribs 48 extending in the front-rear direction are radially arranged equally on the inner periphery of the front half portion 41 (FIG. 3C). A portion of the tip joint 61 of the refill 60 (see FIGS. 1D and 1E) is press-fitted into the tip side rib 48. Therefore, the refill 60 is also held at the tip side rib 48 portion.

  As a better forming method, as shown in FIG. 6A, a split mold 70 for forming the outer diameter of the front shaft 40 and a core pin 80 for forming the inner space of the front shaft 40 are formed. A mold can be adopted. Here, the core pin 80 is divided into a front core pin 81 and a rear core pin 82, of which a part of the surface near the rear end of the front core pin 81 is chamfered so as to be evenly distributed radially. It is a meat part forming part 83. Then, as shown in FIG. 6B, resin is injected into a cavity 90 formed between the split mold 70 and the core pin 80, so that the inner peripheral surface of the injection-molded front shaft 40 is shown in FIG. A thick portion 42 as shown in FIG. That is, since the thick part 42 is not formed as an undercut, the thickness can be easily adjusted, so that the air flow rate can be freely set.

  INDUSTRIAL APPLICABILITY The present invention can be used for a writing instrument such as a ballpoint pen in which a refill is accommodated in a shaft tube formed of a material such as wood that is likely to vary in dimensions.

10 Writing instrument 15 shaft cylinder
20 Cap 21 Clip 22 Vent
23 Front side locking part 24 Rear end side locking part
30 Shaft coupling 31 Small diameter portion of shaft coupling 32 Large diameter portion of shaft coupling
33 Male thread
40 Front shaft 41 Front shaft front half 42 Thick part
43 Gap 44 Tip locking ridge 45 Air replacement hole
46 Second half of front shaft 47 Female thread 48 Tip side rib
50 Tail plug 51 Small diameter part of tail plug 52 Large diameter part of tail plug
53 Rear end face 54 Rear end side locking protrusion 55 Space
56 Rear end receiving part 57 Rear end side rib
60 Refill 61 Tip fitting 62 Ballpoint pen tip
70 Split type
80 Core pin 81 Front core pin 82 Rear core pin
83 Thick part forming part
90 cavity

Claims (4)

The refill is housed in the barrel,
A writing instrument in which a tip shaft made of synthetic resin is fitted to the tip of the shaft cylinder,
A thick wall portion radially arranged at a plurality of locations on the inner peripheral surface of the front shaft is provided, the thick wall portion contacts and holds the outer periphery of the refill, and a gap between the thick wall portions is provided. A writing instrument, wherein air can flow between the outside and the inside of the shaft tube.   The writing instrument according to claim 1, wherein a tail plug is fixed to a rear end of the shaft cylinder, and a rear end of the refill is held in contact with the tail plug.   The writing instrument according to claim 1, wherein an air replacement hole is formed in a side surface portion of the front shaft.   The writing instrument according to claim 1, 2, or 3, wherein the shaft tube is made of wood.

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