JP2004351735A - Ball-point pen tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly productive ball-point pen tip which has a hall arranged in an opening part at the head of a tip and a coil spring arranged behind the ball and also a small diametral part formed in the middle of the coil spring with a seating ring formed at least at one end. <P>SOLUTION: The ball-point pen tip is structured of the ball arranged in the opening part at the head of the tip and the coil spring arranged behind the ball. In addition, the small diametral part is formed in the middle of the coil spring and the seating ring is formed at least at one end of the coil spring. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ballpoint pen tip in which a ball is arranged at an opening at the tip of the tip and a coil spring is arranged behind the ball.
[0002]
[Prior art]
As an example, in a tip of a ball-type liquid container in which a coating ball is rotatably held at the tip of a holder, a coil spring which is bent by writing pressure is provided in the holder, and the front end of the coil spring is extended. A ball-point pen which is pressed into contact with the ball through a liquid guide hole in the tip of the holder, and a rear end of the coil spring is a large diameter end winding portion, and a rear end of the holder is caulked to form a rear end caulking portion. A chip is known (see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2000-203187 (solution means and FIG. 1 etc.).
[0004]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional configuration, since the rear part of the coil spring is a large diameter part, the work of separating the coil spring before assembly is complicated. More specifically, generally, coil springs are stored in a bag or a box in units of 300 to 6000 pieces, and are taken out one by one from the box and inserted into a holder. In this state, the small-diameter portion of the other coil spring (the side opposite to the large-diameter portion) has bitten into the large-diameter portion of the coil spring while being stored in the box (see FIG. 5). Then, the insertion work is performed while separating the two coil springs that have been bitten.
In recent years, mass production has been improved by using a machine or the like in order to improve mass productivity.However, since it has been in the state described above, it is difficult to separate even when using a parts feeder, etc. The intended mass productivity was not obtained.
[0005]
[Means for Solving the Problems]
The present invention is a ballpoint pen tip in which a ball is arranged at a tip opening of the tip, and a coil spring is arranged behind the ball, wherein a small diameter portion is formed in an intermediate portion of the coil spring, and at least one end is formed. The gist is that an end winding portion is formed in the portion.
[0006]
[Action]
Another coil spring having the same diameter as the end of the coil spring abuts on the end of the coil spring.
[0007]
【Example】
One example of the present invention will be described with reference to FIGS. The tip of the ink pipe 2 containing the so-called shear-thinning ink 1 has a low viscosity in a static state and a high viscosity in a dynamic state. The ball-point pen tip 3 is press-fitted and fixed. Incidentally, the ink viscosity in this embodiment is 140 to 245 mpa · s in a static state, but may be 100 to 2000 mpa · s. The inner diameter of the ink pipe 2 is 1.70 to 1.78 mm, but may be 1.5 to 3.0 mm. Here, reference numeral 4 denotes a backflow prevention body that follows the consumption of the ink 1, and prevents the outflow of the ink 1 from the rear end of the ink pipe 2. The backflow preventive body 4 is formed by gelling a non-volatile organic liquid such as silicone grease, polybutene, α-olefin oligomer, ethylene-α-olefin oligomer, etc., but is a resin member such as polyethylene terephthalate. Is also good.
A small diameter portion 5 is formed on the outer periphery of the rear portion of the ballpoint pen tip 3, while a conical portion 6 is formed on the front front portion. Further, an ink circulation hole 7 is formed inside the ballpoint pen tip 3, and the ink circulation hole 7 includes a rear large diameter portion 7a and a front small diameter portion 7b. A discharge port 8 is formed at the end of the small diameter portion 7b, and a ball B made of carbide, stainless steel, ceramics, zirconia, or the like is rotatably fixed to the discharge port 8.
[0008]
A coil spring 9 is disposed in the ink flow groove 7. The coil spring 9 will be described. An end winding portion 10 of about one turn is formed in front of the coil spring 9, and a straight portion 11 is formed extending from the center thereof toward the front. The tip of the linear portion 11 is in contact with the ball B. That is, the contact of the linear portion 11 causes the ball B to contact the inner peripheral surface of the ejection portion 7.
On the other hand, a small diameter portion 12 is formed at an intermediate portion (rearward) of the coil spring 9. Incidentally, the outer diameter of the small diameter portion 12 is formed to be slightly smaller than the inner diameter of the other portions. Around the end portion 13 of about two turns is formed behind the small diameter portion 12, that is, at the rear end of the coil spring 9, the outer diameter of the end turn portion 13 is other than the small diameter portion 12. It has the same outer diameter as the part. The rear end of the coil spring 9 (end winding portion 13) is in contact with the inner peripheral surface of the caulking portion 14 which is formed circumferentially inward at the rear end of the ballpoint pen tip 3 and Dropping from the ballpoint pen tip 3 is prevented.
[0009]
Next, a method of mounting the coil spring 9 in the ballpoint pen tip 3 will be described. First, a coil spring 9 longer than the length of the ballpoint pen tip 3 is inserted into the ink circulation hole 7 from behind the ballpoint pen tip 3 where the caulked portion is not formed. That is, in this state, the rear end of the coil spring 9 projects from the rear end of the ballpoint pen tip 3. In this case, since the coil springs 9 are in an independent state, they can be easily separated one by one. Next, the rear end portion of the ball-point pen tip 3 is pressed by a caulking jig 15 to form a caulking portion, and a small diameter slightly larger than the small diameter portion 12 of the coil spring 9 is provided in front of the caulking jig 15. A part 16 is formed. That is, the small diameter portion 16 of the caulking jig 15 is brought into contact with the small diameter portion 12 of the coil spring 9, whereby the coil spring 9 can be maintained in a contracted state. Can be formed (see FIG. 4). In the present embodiment, the caulking portion 14 is formed over the entire periphery of the rear end of the ball-point pen tip 3, but may be formed partially, for example, radially at three or four locations. The flowability with the ink pipe in the portion other than the caulking portion becomes good, and for example, when performing a defoaming operation, bubbles in the ballpoint pen tip can be easily guided into the ink pipe and can be removed. Become like
[0010]
In addition, as in the present invention, by forming a small diameter portion in the middle portion of the coil spring, even when writing with the ballpoint pen facing upward, the backflow of the ink is slightly prevented, so that the writing distance increases and the ink distance increases. Even in the case where a part chamber having high sedimentation property is contained, the effect is obtained that good writing is obtained because the small diameter part is agitated.
[0011]
【The invention's effect】
The present invention is a ballpoint pen tip in which a ball is arranged in a tip opening of the tip and a coil spring is arranged behind the ball, wherein a small diameter portion is formed in an intermediate portion of the coil spring and at least one end is formed. Since the end winding portion is formed in the portion, a ball-point pen tip having excellent productivity can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing one example of the present invention.
FIG. 2 is an enlarged vertical sectional view showing a ballpoint pen tip.
FIG. 3 is a top view of FIG. 2;
FIG. 4 is a schematic view showing a mounting method.
FIG. 5 is an external view showing a conventional example.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 Ink 2 Ink pipe 3 Ballpoint pen tip 4 Backflow prevention body 5 Small diameter section 6 Conical section 7 Ink circulation hole 8 Discharge port 9 Coil spring 10 End winding section 11 Linear section 12 Small diameter section 13 End winding section 14 Caulking section 15 Caulking Jig 16 Small diameter part B Ball

Claims (4)

A ball-point pen tip in which a ball is disposed at a tip opening of the tip, and a coil spring is disposed behind the ball. A ball-point pen tip characterized by forming a portion. A ball-point pen tip in which a ball is arranged at the tip opening of the tip, and a coil spring is arranged behind the ball. A ball-point pen tip characterized in that the pitch in the portion is substantially the same. The ball-point pen according to claim 1 or 2, wherein a caulking portion is formed inward at a rear end of the tip, and a rear end of the coil spring is brought into contact with the caulking portion. Chips. The ball-point pen tip according to any one of claims 1 to 3, wherein an ink storage part is arranged behind the ball-point pen tip, and the ink storage part stores ink having a shear thinning property.

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