JP2514862Y2 - Small tube writing instrument - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a small tube-type writing instrument having a hard small-diameter pipe provided at its tip for use in a plotter pen or a drawing pen.

[Conventional technology]

Conventionally, this type of small-tube writing instrument has a metal or resin core fixedly attached to a weight and slidably incorporated in a small-diameter pipe made of a hard material. The structure was such that the tip of the core protrudes from the tip of the small diameter pipe.

The reason for this is to prevent the ink passage from being blocked by the coagulation of the ink in the pigment ink, to prevent paper jam in the hard small-diameter pipe, and to increase the capillary action in the small-diameter pipe to improve the ink follow-up. That was the purpose.

[Problems to be solved by the device]

However, in the above-mentioned conventional one, since the core protruding from the tip of the small-diameter pipe is worn by writing, the tip of the core becomes an edge shape, and if the writing is continued in this state, the fibers of the paper will be removed at the edge of the core. It was often scratched and caused a paper jam, making writing impossible. This phenomenon has become a serious problem because small-tube writing instruments with small widths, such as 0.18 mm, 0.25 mm, and 0.35 mm, have recently been frequently used. Moreover, since the weight fixed to the rear part of the center core vibrates in the front shaft, when writing at high speed or when used for a plotter pen with severe ups and downs, it changes the outflow of ink and the handwriting is blurred. It was a serious problem in the finish of the drawing.

Therefore, the present invention provides a small-tube writing instrument that eliminates abrasion of the core, prevents paper jams, and always provides stable ink following.

[Means for solving the problem]

The small-tube writing instrument of the present invention is provided with a small-diameter pipe made of a hard material at the tip of the small-diameter pipe holding member, and an ink passage is formed by extending the inner hole of the small-diameter pipe or the small-diameter pipe holding member to the small-diameter pipe holding member. A straight line portion slightly shorter than the total length of the ink passage from the rear end edge of the ink passage to the tip of the small diameter pipe, and a mounting portion projecting in the outer peripheral direction is provided at the rear of the straight line portion to form a core. To do. It is characterized in that the mounting portion of the core is located behind the trailing edge of the ink passage, and the tip of the core is always recessed from the tip of the small diameter pipe.

〔Example〕

FIGS. 1, 2 and 3 show a small-tube writing instrument according to the first embodiment of the present invention, in which a front shaft 2 is press-fitted and joined to a front portion of an ink tank 1 storing dye ink, A plurality of annular grooves 2B are formed on the outer peripheral surface of the front shaft 2 so as to communicate with the air inlet 2A and adjust the internal pressure. An air passage 2C extending in the longitudinal direction is formed in the annular groove 2B, and the air introduced from the air inlet 2A flows into the ink tank 1 through the air passage 2C and the air outlet 2D. A holder 3 made of resin is press-fitted and attached to the tip portion of the tip shaft 2, and a small-diameter pipe 4 made of a hard material such as ceramic is press-fitted and attached to the holder 3. Further, the protection pipe 5 made of metal such as stainless steel for protecting the small diameter pipe 4 is the small diameter pipe 4.
Is fitted on the outside of. The configuration up to this point is a configuration that has been generally implemented in the past, so only a brief description will be given. Further, an ink passage is formed by extending from the inner hole 4A of the small diameter pipe 4 to the fine hole 3A of the holder 3, and is slightly shorter than the total length of the ink passage from the tip of the small diameter pipe 4 to the rear end edge 3B of the ink passage of the holder 3. The straight line portion 6A is formed on the core 6. A mounting portion 6B protruding in the outer peripheral direction is formed at the rear portion of the straight portion 6A of the center core 6. The straight portion 6A of the core 6 is inserted from the rear end of the ink passage and arranged in the inner hole 4A of the small-diameter pipe 4, and the mounting portion 6B of the center core 6 is connected to the rear end edge 3B of the ink passage of the holder 3. It is held by a front end 7A of a joint 7 press-fitted and fixed to the shaft 2, and the core 6 is attached without moving in the longitudinal direction. Moreover, as described above, since the straight portion 6A of the core 6 is formed slightly shorter than the entire length of the ink passage, the tip of the core 6 is always slightly recessed from the tip of the small diameter pipe 4. The joint 7 provided on the front shaft 2 guides the ink in the ink tank 1 to the ink reservoir of the holder 3 and prevents the ink in the ink tank 1 from being violated by vibration during writing. Therefore, a plurality of ribs 7C protruding inward are formed in the inner hole 7B of the joint 7 so as to extend in the longitudinal direction.

As for the shape of the mounting portion of the core, as shown in FIGS. 4 and 5, the rear portion of the straight portion 6A of the core 6 is bent to form a mounting portion 6B protruding in the outer peripheral direction, or As shown in FIGS. 6 and 7, it is conceivable that the rear portion of the straight portion 16A of the core 16 is projected toward both sides in the outer peripheral direction to form the mounting portions 16B. The configuration is not limited to the above, and any configuration may be used as long as the mounting portion appropriately protrudes in the outer peripheral direction and the mounting portion does not block the ink passage of the holder.

The cross-sectional shape of the straight portion of the core is not limited to the circular shape, but may be a polygonal shape or an irregular shape, or may have a groove extending in the longitudinal direction on the outer circumference.

Further, the material of the core is not limited to metal, but resin, ceramic, or the like can be considered.

FIG. 8 shows a small-tube writing instrument according to a second embodiment of the present invention, in which a center core is provided between the rear end edge 3B of the ink passage of the holder 3 and the front end 7A of the joint 7 fixed to the front shaft 2. 6 mounting part
6B is a loose fit with appropriate play. Therefore, the center core 6 can be appropriately moved in the small diameter pipe 4, but the length of the straight portion 6A of the center core 6 is slightly shorter than the total length of the ink passage from the rear end edge 3B of the ink passage of the holder 3 to the tip of the small diameter pipe 4. Therefore, the tip of the core 6 is always recessed from the tip of the small diameter pipe 4.

FIG. 9 shows a third embodiment of the present invention, in which a joint 17 is integrally formed with the front shaft 12. Therefore, the mounting portion 6B of the core 6 is held between the rear end edge 3B of the ink passage of the holder 3 and the front end 17A of the joint 17.

In the embodiments of the present invention described above, the holder for the small-diameter pipe holding member to which the small-diameter pipe is attached has been described.
The small-diameter pipe holding member is not limited to the holder, but as shown in FIG.
The small diameter pipe 4 may be directly attached to the front shaft 22.

Further, the ink passage does not necessarily have to be constituted by the small diameter pipe and the small diameter pipe holding member. As shown in FIG. 1, the small diameter pipe 14 is extended rearward from the holder 13 so that the ink passage is provided with the inner hole 14A of the small diameter pipe 14. It is also possible to form the mounting portion 6B of the center core 6 between the joint 7 and the rear end edge 14B of the ink passage of the small diameter pipe 14 by forming only the mounting portion 6B.

[Action]

In the small-tube writing instrument according to the present invention described above, since the inner core is always immersed in the small-diameter pipe and does not come into contact with the paper surface, there is no fear of the inner core being worn and the paper jam can be prevented. . Moreover, the most important function of providing the core of the present invention is that the core core slightly immersed in the small diameter pipe works the capillary action to reliably follow the ink to the tip of the small diameter pipe, and it is fixed to the conventional core core. The built-in weight is eliminated and the assemblability is significantly improved, and even under high-speed and severe up-down use conditions such as with a plotter, there is no variation in the ink flow rate caused by vibration of the weight, and stable ink follow-up is always obtained It is what is done.

[Effect of device]

The present invention is as described above, and since the tip of the core is always immersed in the small-diameter pipe, the core is not worn by writing, paper jams are eliminated, and durability is improved. Further, since it is not necessary to fix the weight to the core, the assembling property is remarkably improved. Furthermore, the ribs of the joint and the capillary action of the small-diameter pipe and the center core prevent the ink in the ink tank from being disturbed by the vibration during writing to the writing part, and it can operate at high speed and up / down like a plotter. The ink follows constantly even under severe use conditions.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a small-tube writing instrument of the present invention,
2 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is a cross-sectional view taken along the line BB of FIG. 1, and FIG. 4 is a front view showing the core of the present invention. 5 is a right side view showing the core of FIG. 4,
FIG. 6 is a front view showing another embodiment of the center core, FIG. 7 is a right side view showing the center core of FIG. 6, and FIGS.
FIG. 11 and FIG. 11 are vertical cross-sectional views of main parts showing another embodiment of the present invention. 1 …… Ink tank 2 ・ 12 ・ 22 …… Spindle 3 ・ 13 …… Holder 3B …… Ink passage rear end edge of holder 3 ・ 14 …… Small diameter pipe 4A ・ 14A …… Small diameter pipe 4 ・ 14 Hole 14B …… Ink passage rear edge of small diameter pipe 14 …… Protection pipe 6 ・ 16 …… Center core 6A ・ 16A …… Straight section of center core 6 ・ 16B ・ 16B …… Mounting center core 6 ・ 16 Part 7 ・ 17 …… Joint

Claims (1)

(57) [Scope of utility model registration request] 1. A small diameter pipe holding member comprising an ink tank storing ink, a tip shaft attached to the front part of the ink tank, a tip shaft or a holder fixed to the tip shaft, and a tip of the small diameter pipe holding member. A small-diameter pipe that is attached to the pipe part, a core in which a straight part extending in the longitudinal direction is located in the small-diameter pipe, and a joint that is integrally formed with or fixed to the tip shaft. Of the linear portion, the mounting portion projecting in the outer peripheral direction is formed, and an ink passage is formed by extending the inner hole of the small-diameter pipe or the small-diameter pipe inner member to the small-diameter pipe holding member, and further, in the inner hole of the joint. A plurality of ribs are formed to protrude inward and extend in the longitudinal direction for good ink following, and the center core mounting part is located between the trailing edge of the ink passage and the front end of the joint to allow ink passage. Canalicular type writing instrument that features the straight tip position has been central core is always configured slightly retracted from the small diameter pipe tip within.