JP4972934B2 - Fountain pen shaft structure - Google Patents

Description

  The present invention relates to a fountain pen in which a writing unit composed of a nib and a pen core is arranged in a front part of a fountain pen body.

In a conventional fountain pen, the tip has a hard writing tip made of iridosmin or the like, and a pen tip formed of 14 gold and the like and a pen core having an ink groove, an air groove, and a comb groove are press-fitted into the shaft cylinder. Alternatively, products and inventions fixed by bonding are widely known. There is also known a product in which the rear part of the pen tip and the rear part of the pen core are screwed into a hole in the shaft tube and fixed by adhesion. This reliably prevents the pen tip and the pen core from rotating and coming out of the barrel.
Japanese Patent Application Laid-Open No. 10-077675

In the fountain pen, the rear part of the pen tip and the rear part of the pen core are held at the front part of the shaft tube, and the specific holding means adopts a screwing structure.
By the way, in recent writing instruments, an improvement in design has been desired, and an interesting design and a high-class design have been favored. Therefore, in order to produce a high-class feeling, an emblem or a pattern is provided on the surface of the shaft tube or the nib, or a product having a feature in the external shape of the shaft tube has been put on the market.
However, in the prior art as described above, since the pen tip and the shaft tube are fixed by means such as screwing, the fixing position varies depending on the assembled object. The position of the shaft cylinder pattern and the coat of arms did not match, and the design of the parts alone was good, but the corner design was made bad by assembling. Although there is a case where the pen tip is press-fitted or adhered to the shaft tube, once it is assembled, it is difficult to repair, and there is a risk that it will be destroyed.

Therefore, the present invention has been made in view of the above problems, and a writing unit composed of a pen tip and a pen core is disposed in the front part of the fountain pen body, and between the fountain pen body and the writing unit unit. A fountain pen with a holder interposed therein, wherein a reduced diameter portion is formed on the inner surface of the rear portion of the holder, and an intermediate step of the writing unit is formed on the inner surface step portion of the holder formed by forming the reduced diameter portion. In the fountain pen with which the part is in contact , the writing unit is disposed so as to be rotatable with respect to the fountain pen body, and its rotational resistance is in the range of 2 N · cm to 5 N · cm. The gist is that the portion to be applied is provided on the outer peripheral surface corresponding to the reduced diameter portion of the holder .

The present invention is a fountain pen in which a writing unit comprising a nib and a pen core is arranged in the front part of the fountain pen body, and a holder is interposed between the fountain pen body and the writing unit, and the rear part of the holder In a fountain pen in which a reduced diameter portion is formed on the inner surface, and an intermediate step portion of the writing portion unit is brought into contact with an inner step portion of the holder formed by forming the reduced diameter portion , the writing portion unit is It is arranged so as to be rotatable with respect to the fountain pen body, its rotation resistance is in the range of 2 N · cm to 5 N · cm, and the portion to which the rotation resistance is applied corresponds to the reduced diameter portion of the holder. Since it is provided on the outer peripheral surface, the position of the writing unit in the rotation direction can be easily matched to the position of the pattern attached to the fountain pen body and the shape of the tail plug.

A first example will be described with reference to FIGS. The nib 1 is made of 14 gold or the like, and has a hard writing tip 1a made of iridosmin or the like at its tip. A slit 1b is provided in the axial direction from the writing tip 1a to about one third of the front of the nib 1. A circular hole 1c is formed at the end of the slit 1b perpendicular to the axial direction of the nib 1. The hole 1c prevents stress concentration at the end of the slit 1b because a force is applied to open the pen tip around the slit 1b during writing. The shape of the hole 1c is arbitrary, and may be a heart shape, for example. The front part of the nib 1 is formed in a tapered shape, and the cross-sectional shape thereof is formed in an arc from the vicinity of a half from the front end. For decoration, the top surface of the nib 1 is engraved, plated, or printed with patterns such as letters and emblems, creating a luxury and brand image.
A pen core 6 is disposed in contact with the back surface of the pen tip 1. The pen core 6 has a cylindrical cross-sectional shape, and the front portion of the pen core 6 is notched in a circular arc shape so that it does not come into contact with a writing object, for example, a paper surface during writing. ing. The notch 6a is not limited to an arc shape, but may be a straight shape.
The pen tip 1 and the rear part of the pen core 6 are attached to the shaft cylinder 2 via a holder 9, and the shaft cylinder 2 is screwed to the rear shaft cylinder 3. Thereafter, a hole 3a for storing the emblem 4 is formed on the side surface of the front portion of the shaft tube 3, and is fixed by means such as fitting or adhesion. On the other hand, a conical tail plug 5 is fixed to the rear end of the rear barrel 3 by screwing, and is bonded and fixed to improve the fixing reliability. In the longitudinal direction of the side surface (arc portion 5a) of the conical tail plug 5, two parallel protrusions 5b are formed up to the top portion 5c.
And the direction of the rotation direction of the protrusion 5 of the nib 1 and the coat of arms 4 and the tail plug 5 is aligned so as to be positioned in a straight line from the viewpoint of design. That is, when the orientations of the nib 1, the crest 4, and the arc portion 5 a of the tail plug 5 are aligned, a product with a sense of quality is produced.

A cap 7 is detachably screwed in front of the rear barrel 3. An outer cylinder 8 is fixed to the cap 7 by means of fitting and adhesion, and the outer cylinder 8 is formed with a notch 8a having a pattern like a decorative window. A head crown 9 is fitted and bonded to the cap 7 via a core 11 at the front portion of the cap 7. A gemstone 9b such as a ruby is bonded and fixed to the side surface of the crown 9, and an arc groove 9c is formed along the outer periphery of the crown 9. A clip 10 is fixed to the head crown 9 by a spring 13 and a screw 14.
On the other hand, a screw member 15 is fixed to the inner surface of the rear portion of the cap 7, and a female screw portion 15a formed on the screw member 15 is detachable from a male screw portion 2b formed on the outer periphery of the rear portion of the shaft tube 2. It is screwed. The direction of rotation of the clip 10 after the cap 7 and the front shaft 2 are screwed is aligned with the pen tip 1, the crest 4, and the projection 5 of the tail plug 5. The position is adjusted.
A cylindrical hole 9a is formed in the inner diameter portion of the head crown 9 in the axial direction, and the front outer peripheral portion of the core 11 is fitted and bonded to the hole 9a. The front end of the core 11 is fitted until it contacts the bottom of the hole 9a of the head crown 9. The diameter of the outer periphery of the rear part of the core 11 is larger than that of the front part. As a result, the inner periphery of the core 11 is also formed with a small front part and a large rear part.
Further, a groove 11a is formed in the inner periphery of the rear portion of the core 11, and a shoulder 12a having a different diameter portion of the inner cap 12 formed with a small diameter at the outer periphery of the tip is applied to the rear end portion of the core 11. It is in contact and mating. A rib 12b is formed on the outer periphery of the middle cap 12 near the front center, and engages with the groove 11a of the core 11. Due to this engagement, it is difficult to pull out the inner cap 12 fitted to the core 11 in the axial direction. In this example, a force of 30 N or more is required. Further, a rib 12c is formed on the circumference of the center outer periphery of the middle cap 12 on the circumference. The ribs 12 c are in contact with the inner periphery of the cap 7 and prevent the ink near the nib 1 from evaporating through the hole in the crown 9. Further, a plurality of ribs 12 d are formed in the inner circumference of the middle cap 12 in the axial direction. The rib 12d comes into contact with the outer periphery of the rear cylinder shaft 3 when the cap 7 is fitted to the rear cylinder 3 in writing. Incidentally, the thickness of the rear part of the middle cap 12 becomes thinner toward the rear part, and the thickness at the rear end part is 0.3 mm. This is because when the cap 7 is fitted to the rear barrel 3, the middle cap 12 abuts and bulges outward to produce a moist fit. The middle cap 12 is preferably made of a resin such as polypropylene or polyethylene in order to prevent the ink from evaporating.
The outer periphery of the screw member 15 is fitted and bonded to the inner periphery of the rear portion of the cap 7. A female screw 15a is formed on the inner periphery of the screw member 15, and is screwed with a male screw 2a formed on the outer periphery of the shaft cylinder 2, and is brought into contact with the front portion of the rear cylinder shaft 3 to be screwed. Until it stops. The material of the screw member 15 is required to have mechanical strength, and acrylonitrile, butadiene, and styrene are used in order to prevent damage due to contact with the front end of the rear cylinder shaft 3, but this is limited to this. There is nothing. In addition, by screwing the screw member 15 and the shaft cylinder 2, it is possible to prevent evaporation of ink near the pen nib 1 as much as possible, and the front end portion of the rear shaft cylinder 3 is abutted against the rear end portion of the screw member 15. By contacting the ink, the evaporation of the ink is prevented as much as possible.

The rear shaft cylinder 3 includes a screw core 17, a decoration ring 18, and an outer shaft 19. A decorative ring 18 is attached to the outer periphery of the screw core 17. Specifically, it is mounted until the inner peripheral shoulder 18a of the decoration ring 18 abuts against the front end portion of the rear barrel 3, and is fitted, adhered and fixed. The inner periphery of the decorative ring 18 is fitted, fixed and fixed until the inner periphery of the outer shaft 19 abuts against the inner diameter of the shoulder 18b on the outer periphery of the decorative ring 18. The tail plug 5 is screwed and bonded to the rear inner periphery of the outer shaft 19.
A cylindrical protrusion 2 a is formed on the inner periphery of the rear portion of the shaft cylinder 2 so as to face rearward. The front cylinder 16a of the ink tank 16 is detachably press-fitted into the protrusion 2a. The front cylinder 16a is press-fitted until it comes into contact with the shaft cylinder 2. The ink tank 16 can store 0.8 cc of ink.
Further, the inner end of the tail plug 5 fixed to the rear end of the outer shaft 19 is press-fitted and fixed with the outer periphery of a spring 20 such as a coil spring in contact therewith. On the other hand, the front end of the spring 20 abuts on the ink tank 16 and compresses it to urge the ink tank 16 forward. Incidentally, the buffering action of the spring 20 is used to prevent the ink tank 16 from being detached from the cylindrical protrusion 2a due to an impact such as dropping.

Next, the pen core 6 and the core 21 inserted in the pen core 6 will be described in detail. A hole 6a having a circular cross section is formed inside the pen core 6 in the axial direction, and a core 21 is inserted into the hole 6a. An ink groove 21a through which ink passes from the ink tank 8 to the nib 1 is formed in the core 21. In this example, the width of the ink groove 21a is 0.1 mm to 0.2 mm. . Further, an air groove 21b is formed on the opposite side of the ink groove 21a of the core 21 so that air is replaced according to the use of the ink, and the cross-sectional area is 0.3 mm ² to 0.5 mm ² . It has become. A large-diameter neck portion 21c is formed at the front end portion of the core 21, and a circumferential groove portion 21d is formed at the rear portion of the neck portion 21c. The groove 21d is connected to the air groove 21b. That is, when an impact is applied due to the fall of the fountain pen or the like, the ink in the ink tank 8 is ejected from the tip of the core 21 through the air groove 21b by the impact force, and the groove portion 21d formed at the rear of the neck portion 21c. This is preventing it. That is, the ink accelerated by the impact is relaxed by the groove portion 21d, and the ink which is about to be ejected by the rear wall surface of the neck portion 21c is eaten.
On the other hand, the pen core 6 is provided with a plate-like comb groove 6b that temporarily holds ink pushed out from the ink tank 8 due to changes in atmospheric pressure or temperature. A plurality of comb portions 6b are formed in the circumferential direction of the nib 6. In this example, the interval between the comb grooves 6b is formed from 0.3 mm to 0.7 mm. The width of the comb grooves is wide at the rear portion of the pen tip 1, and the width is gradually narrowed toward the front.
Further, a slit 6 c is formed on the pen point 1 side of the pen core 6. The slit 6 c is a slit for guiding the ink guided to the pen core 6 to the comb groove 6 b located on the side opposite to the pen tip 1. On the other hand, a notch 6d having a width larger than the width of the slit 6c is formed on the side opposite to the slit 6c. The notch 6d is an air groove of the pen core 6, and the air in the pen core 6 is replaced through the notch 6d.

  The material of the nib 1 is not only 14 gold but also stainless steel that is resistant to corrosion by ink. The nib 1 is mounted on the holder 22, but is mounted so that it cannot rotate. More specifically, a horseshoe-like groove 22a is formed from the front end to the rear of the inner surface of the holder 22, and the rear part of the pen tip 1 is inserted into the horseshoe-like groove 22a. Positioning in the rotational direction with respect to 22 is performed. Further, the pen nib 1 and the pen nib 6 are fixed to the holder 22 by inserting the pen nib 6 into the holder 22 to which the pen nib 1 is inserted and press-fitting. The writing unit is configured by combining the nib 1 and the pen nib 6. In this example, the pen nib 1 and the nib 6 are combined with the holder 22 to prevent disassembly. Yes. The height of the horseshoe-shaped groove 22a is set narrower in the range of 0.02 mm to 0.1 mm than the combined height of the pen tip 1 and the pen core 6. That is, as described above, the pen tip 1 and the pen core 6 are inserted into the holder 22 together to be in a press-fitted state. Incidentally, in this example, the pen tip 1 and the pen core 6 once inserted and press-fitted cannot be pulled out unless the force is 20 N or more. In addition, when the height of the horseshoe-shaped groove 22a is narrower than 0.02 mm than the combined height of the pen tip 1 and the pen core 6, the pen tip 1 and the pen core 6 pressed into the holder 9 have a force of less than 20N. The holder 22 may be pulled out and come off due to an impact such as dropping. On the other hand, when the height of the horseshoe-shaped groove 22a is 0.1 mm or more narrower than the combined height of the pen tip 1 and the pen core 6, the pen tip 1 and the pen core 6 pressed into the holder 22 have a force of 50 N or more. If it is not added, it will not be pulled out and there is a risk of destroying precision parts such as the nib 1 and the pen nib 6. Note that it is inconvenient for a fountain pen that requires maintenance that it cannot be pulled out (cannot be disassembled) without destroying the pen tip or the like. In particular, in recent years, recycling has become popular, and many users have come to recognize it, and a fountain pen that can be maintained is desired.

A concave groove 23 is formed in the rear part of the outer periphery of the holder 22, and an elastic body 24 made of a rubber material is fitted into the concave groove 23. The elastic body 24 is fitted in a state where about half of the elastic body 24 is exposed from the groove 23. The holder 22 in which the elastic body 24 is fitted is inserted in a state of being press-fitted into the front inner surface of the shaft tube 2, but is rotatable with respect to the shaft tube 2. Rotation resistance is given even if it says that it can rotate freely. That is, in this example, when the holder 22 is attached to the shaft tube 2, the elastic body 24 is compressed and deformed to give rotational resistance. That is, the rotational resistance can be varied according to the amount of deformation. For example, if an elastic body having a large cross-sectional shape is used, the rotational resistance is increased. Conversely, if a thin elastic body is used, the rotational resistance is decreased. The rotational resistance is preferably in the range of 2 N · cm to 5 N · cm. By the way, when the writing speed is 2 N · cm or less, the pen tip 1 rotates around the rear barrel 3 at the time of writing, and the writing becomes uncomfortable, and when the torque is 5 N · cm or more, When a force is applied to rotate the nib 1 with respect to the axial direction, an excessive force acts on the nib 1 and the nib 6 and there is a risk of deformation or damage.
The elastic body 24 having a circular cross-section has a small frictional resistance when fitted in the groove 24 of the holder 22 and is easy to mount, but is not necessarily limited to a circular shape. For example, an elastic body having a rectangular cross section may be used. When the cross-sectional shape is rectangular, a large force is required for mounting, but once it is mounted, it will not easily fall out of the groove 23. The example shown in FIG. 8 is a further modification that imparts rotational resistance, and is an example in which the columnar elastic body 25 is detachably attached to the holes 26 formed radially at the rear part of the holder 22, but is bonded. You may fix by. The example shown in FIG. 9 is an example in which a plate-like elastic body 27 is mounted on the holder 22 instead of the columnar elastic body 25. In any of the examples, the elastic bodies 25 and 27 are partially detachably mounted, and thus the rotational resistance force can be changed and set relatively easily by increasing or decreasing the number of the elastic bodies 25 and 27 to be mounted. Will be able to.
Natural rubber and fluororubber can be used as the material for the elastic bodies 24, 25, and 27 described above. However, natural rubber is desirable when the cost is to be kept low. When a high stability is required, it is preferable to use fluororubber.
Although the elastic body 24 is illustrated as a means for imparting rotational resistance to the shaft cylinder 2 of the holder 22, it may be formed integrally with the holder 22. Specific examples thereof are shown in FIGS. The example shown in FIG. 10 is an example in which a circumferential rib 28 is integrally formed on the outer periphery of the rear portion of the holder 22, and the example shown in FIG. This is an example in which the gap is integrally formed. By integrally forming the holder and the rib, the number of parts is reduced and the number of assembling steps is reduced, so that the cost can be reduced. When the rib is integrally formed on the holder 22, the material of the holder 22 is preferably a resin such as polyacetal or polypropylene.

  As described above, the rotational resistance with the shaft cylinder 2 is obtained by providing an elastic body or rib on the outer periphery of the holder 22, but the elastic body or rib may be provided on the inner surface of the shaft cylinder 2. For example, a circumferential groove may be formed on the inner surface of the shaft tube 2, and an elastic body made of a rubber-like material may be fitted into the groove.

  As described above, the writing unit consisting of the pen tip and the pen core can be rotated with respect to the fountain pen body according to the pattern and design shape of the fountain pen exterior member. it can. Moreover, since an appropriate rotational resistance is provided, the pen tip does not rotate carelessly during writing, and a good writing operation can be obtained. In addition, by pressing and fixing the pen tip and the pen core into the holder, the positions of the pen tip and the pen core in the longitudinal direction and the rotation direction are prevented, and stable writing can be obtained.

The front external appearance perspective view which shows the 1st example of this invention (state which removed the cap). The front external appearance perspective view which shows the 1st example of this invention (at the time of cap mounting). The longitudinal cross-sectional view of FIG. The longitudinal cross-sectional view of FIG. The principal part enlarged view of FIG. AA line sectional view of Drawing 5. BB sectional drawing of FIG. The external appearance perspective view which shows the modification of a holder. The external appearance perspective view which shows the modification of a holder. The external appearance perspective view which shows the modification of a holder. The external appearance perspective view which shows the modification of a holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pen tip 2 Shaft cylinder 3 Back axle cylinder 4 Coat of arms 5 Tail plug 6 Pen core 7 Cap 8 Outer cylinder 9 Head crown 10 Clip 11 Core 12 Middle cap 13 Spring 14 Screw 15 Screw member 16 Ink tank 17 Common core 18 Decoration Ring 19 Outer shaft 20 Spring 21 Core 22 Holder 23 Groove 24 Elastic body 25 Elastic body 26 Hole 27 Elastic body 28 Rib 29 Rib

Claims (2)

A fountain pen with a pen unit and pen core in the front of the fountain pen body and a holder interposed between the fountain pen body and the writing unit. In the fountain pen in which the intermediate step portion of the writing portion unit is in contact with the inner step portion of the holder formed by forming the reduced diameter portion , the writing portion unit with respect to the fountain pen body The rotation resistance is in the range of 2 N · cm to 5 N · cm, and the portion to which the rotation resistance is applied is provided on the outer peripheral surface corresponding to the reduced diameter portion of the holder. A fountain pen characterized by that. The fountain pen according to claim 1, wherein an elastic body is interposed between the holder and the fountain pen body .

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