JP2003170698A - Retractable writing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a writing tip part come out and in by pressing, which can prevent the writing tip part from protruding to damage or strain cloth and a human body therewith even when an external force is applied on a knock part. <P>SOLUTION: In a retractable writing apparatus formed such that a rotor situated at the front end of a pressing rod is rotated by pressing, and a cam part situated at the rotor is locked in a forward and a rearward position in a cam groove formed in a barrel, the barrel is formed such that the front end of a rear barrel is removably fixed at the rear end of a front barrel. A base part provided in front with a clip is formed on one side of the rear end of the rear barrel, a stopper piece is protruded with one end connected to one side of a pressing member, the front end of the stopper piece is positioned on the front surface of the base part in a space part formed between the inner surface side of a clip and the outer surface of the rear barrel, and along with advancing of the pressing part, the front end part of the stopper piece is advanced in a space part formed in the inner surface side of the clip. Even when an external force is applied on the rear end of the pressing member during carriage, the front end of the piece part makes contact with the upper edge of a pocket, and pressing can be checked. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knock-type writing instrument equipped mainly with a ballpoint pen writing body filled with a low-viscosity ink such as an aqueous ink having a shear thinning property or an oil-based ink having a low viscosity.

[0002]

2. Description of the Related Art A writing instrument devised so that the writing instrument is fixed to the chest pocket of the clothes while the writing part is projected from the tip of the shaft and the ink of the writing part does not stain the clothes. Exists. Further, there is also known a knock-type writing instrument in which a writing tip portion is made to project and retract from a shaft tip opening by using a knock mechanism composed of a cam barrel, a knock rod, and a rotating cam member.

Conventionally known oil-based ballpoint pens have a high resistance when the ball rotates when the ink flows out from the pen tip because the viscosity of the ink used for the oil-based ballpoint pens is several thousand mPa · S or higher. Therefore, there is a drawback that the writing quality is bad.
In addition, there is a problem that the amount of ink flowing out from the tip during writing is small, there is a battering phenomenon, there is uneven writing line, the handwriting density is low, and a high writing pressure is required. As an improvement of this oil-based ball-point pen, a ball-point pen for water-based ink called medium viscosity, which uses an ink in an intermediate viscosity range between water-based and oil-based (several mPa · S to several thousand mPa · S), has been recently developed. This is a ballpoint pen using a relatively low-viscosity water-based ink having a characteristic that viscosity is reduced by the rotation of the tip ball and ink smoothly flows out, so-called shear thinning viscosity. However, since this ink has a defect that the ink is easily dried, a cap for sealing the writing tip is usually required. Further, the outflow amount of ink increases, and in order to extend the writing life, it is necessary to increase the diameter of the ink containing tube to increase the ink filling amount.

Further, as an improvement of the above oil-based ballpoint pen, a ballpoint pen using a low-viscosity oil-based ink having excellent drying resistance is conceivable. However, the ink outflow amount also increases and the ink containing tube is extended in order to extend the writing life. It is necessary to increase the diameter of the ink and increase the amount of ink filled. Also, since the viscosity of the ink is low, if the tip side faces downward, a gap between the tip ball and the tip holding part will cause ink bleeding (direct current), and the amount of ink flowing out during writing will increase. There are drawbacks.

Since the above-mentioned medium viscosity water-based ink and low viscosity oil-based ink are both low-viscosity inks, there is a phenomenon that the ink is likely to flow back or generate direct current. There is a risk of soiling clothes etc. if ink causes backflow or direct current. There is also a drawback that writing blurring is likely to occur due to a drop or knock impact. In addition, since a medium-viscosity water-based ballpoint pen is usually filled with a grease-like translucent non-drying substance called a follower at the rear end of the ink containing tube, the problem of ink evaporation prevention is a problem of the pen tip, that is, the ball and the holder. It may be considered to reduce evaporation from the gap. For example,
If a solvent with a fairly low vapor pressure such as an oil-based ballpoint pen is mainly used, ink evaporation does not have to be considered.

[0006]

The present invention can solve the following problems. In a knock-type writing instrument that is equipped with a ballpoint pen writing body that uses mainly low-viscosity ink and allows the writing tip to project from the tip opening of the barrel, the writing tip projects from the tip opening only by knocking. , It is possible to provide at low cost a structure that is locked in the stored state and the writing tip does not project and the clothing or human body is damaged or soiled even if the knocking part is inadvertently subjected to an external force when it is inserted into a chest pocket or the like. .

[0007]

The present invention has the following constitution in order to solve the above problems. In the knock-type writing instrument according to the invention described in claim 1, the knock rod is moved forward and backward by knocking the knock member protruding at the rear end of the barrel to rotate the rotor provided at the front end of the knock rod. In a knock-type writing instrument configured so that a cam portion provided on the rotor is locked in a cam groove provided in the barrel at forward and backward positions, the barrel has a front shaft The front end of the rear shaft is detachably fixed to the rear end of the rear shaft, a base having a front clip is formed at one side of the rear end of the rear shaft, and the stopper piece is connected to one side of the knock member at one end. And the front end of the stopper piece is positioned on the front surface of the base in the space formed between the inner surface side of the clip and the outer surface of the rear shaft, and the stopper piece is advanced as the knock member advances. The front end of the clip is formed on the inner surface side of the clip Configured to be advanced between portion composed.

A knock-type writing instrument according to a second aspect of the present invention is the knock-type writing instrument according to the first aspect, wherein the stopper piece has two legs in a state where the base of the clip is sandwiched behind the front end. And has a rear end fixed to the knock member.

A knock type writing instrument according to a third aspect of the present invention is the knock type writing instrument according to the first aspect, wherein the front end of the rear shaft is screwed into the rear end of the front shaft.

A knock-type writing instrument according to a fourth aspect of the present invention is the knock-type writing instrument according to the first aspect, wherein the tip ball is always in close contact with the inner edge of the ball holding portion at the tip of the tip by pressing a spring. , A low-viscosity ink is filled in the ink containing tube, and a ball-point pen writing body filled with a grease-like follower that moves according to the consumption of ink at the time of writing is arranged at the front end of the rotor. It will be done.

[0011]

1 to 3 show an embodiment of the present invention. First, as shown in FIG. 1, the barrel is made of resin and the front shaft 20
The front end of the rear shaft 27 is screwed into the rear end. Then axis 2
7. A base portion 23 is integrally formed with a clip 24 on the front side on one side of the rear end. Further, a cam cylinder portion 31 is integrally provided in front of the rear shaft 27, a screw portion 28 is formed on an outer surface of the cam cylinder portion 31, and an inner surface is circumferentially formed by a plurality of grooves and ribs. A so-called cam groove having a cam portion at its tip is formed. Further, inside the cam tube portion 31, there is a knock rod 35 having a cam portion that engages with the cam groove and the rotor 3.
3 is fitted in the cam cylinder so that the shaft can move freely, and the knock rod 35
Each time the rotor moves forward or backward, the rotor 33 is rotated by the indexing angle of the cam groove and is engaged with the tip cam portion of the cam groove to be positioned at the forward or backward position. Cam barrel 31 and knock rod 3
The knock mechanism section composed of 5 and the rotor 33 has the same structure as a well-known Kahn type knock mechanism.

The knock rod 35 and the rotor 33 are provided on the cam cylinder portion 31.
And a knock member 37 is fixed to the rear end of the knock rod 35 by appropriately protruding from the rear end of the rear shaft 27, and a spring is provided between the inner step portion 27a of the rear shaft and the front end of the knock member 37. 40 are laid. The stopper piece 39 has its front end portion 39a positioned in front of the base portion 23 of the clip in a space formed between the inner surface side of the clip 24 and the outer surface of the rear shaft 27, and at the rear of the front end portion 39a. The base portion 23 is sandwiched between the two leg portions, and the ring-shaped mounting portion 39b at the rear end thereof is elastically engaged and fixed to the groove portion 37a provided on the outer periphery of the rear end of the knock member.
The method of fixing the knock member and the stopper piece is not limited to the above-mentioned means, and one end of the stopper piece can be connected to one side of the outer surface of the knock member.

In the above-mentioned embodiment, the clip is formed integrally with the base portion, but it is also possible to provide the clip as a separate body so as to be fixed to the base portion. It is also possible to provide a stopper piece integrally with the knock member. It is also possible to integrally provide the knock rod and the knock member. Furthermore, it is not always necessary to provide the spring 40 that always urges the knock rod and the knock member rearward in a state where the knock rod and the knock member do not knock.

The ballpoint pen writing body 1 is inserted into the inner hole 30 of the front shaft 20 with a return spring 41 interposed, and the rear end of the front shaft 20 to the front end of the rear shaft 27 are mounted and fixed by screwing. It Further, the rear end of the ballpoint pen writing body 1 contacts the front surface of the rotor 33. When the rear end of the knock member 37 is knocked forward, the rotor 33 is positioned at the forward position by the knock rod 35, and the writing tip of the ballpoint pen writing instrument 1 is projected from the tip opening 21 of the tip shaft 20. Becomes

FIG. 3 shows a ballpoint pen writing body 1. The ball-point pen writing body 1 is filled with low-viscosity ink such as medium-viscosity aqueous or low-viscosity oil-based ink having so-called shear thinning viscosity.

The tip 9 is crimped so as to be rotatably held on the inner surface of the tip of the tip 9 with the tip ball 10 being substantially in contact with a seat having a channel into which ink can flow. The spring 12 is inserted into the inner hole of the tip 9, and the rear end of the tip is appropriately crimped so that the rear end of the spring 12 cannot be pulled out. The tip ball 10
It is extremely important for the tip to be in close contact with the inner surface of the tip to prevent the writing tip from drying and to prevent the direct current of the ink. Therefore, if necessary, the surface roughness of the inner surface of the tip that holds the tip ball and the contact accuracy due to caulking In order to improve, the inner surface is ground and the secondary plastic working is performed to improve the crimping accuracy. In addition, surface treatment etc. are taken into consideration on the contact surface with the tip ball. Further, the tip of the spring 12 becomes a linear rod shaft portion 13, and the tip end thereof abuts the back surface of the tip ball 10 in a pressed state. The tip ball 10 is brought into close contact with the inner surface (ball holding portion) of the tip of the tip 9 by the pressing.

The tubular body 2 is formed of a long front shaft portion 3 for crimping the tip 9 to the tip and an ink containing tube 4. Further, the ball valve 1 is provided in the front end inner hole of the front shaft portion 3 so as to face the rear end of the tip 9.
There is provided a valve chamber 5 in which 4 is loosely fitted, and when the tip 9 faces downward, the guide hole 7 is opened so that the ink 16 flows into the inner hole of the tip through the groove 15 or the like, and conversely, when the tip 9 faces downward, the ball valve is opened. Reference numeral 14 seals the guide hole 7 to prevent backflow of ink.

The ink containing tube 4 is filled with medium-viscosity water-based or low-viscosity oil-based ink, and the trailing end of this ink can be moved by contacting the ink surface as the ink is consumed. A follower 17 made of a translucent non-drying substance like a grease is filled. Further, a resin-made follower rod 18 having a specific gravity substantially equal to that of the follower 17 is immersed in the follower 17. (Note that the follower rod 18 is provided especially under the design conditions in which the ink easily flows backward.)

[0019]

The operation will be described below based on the above embodiment.
First, when the rear end of the knock member 37 is knocked forward from the state shown in FIG. 1, the rotor 33 moves forward together with the knock rod 35 to rotate, and is positioned at the forward position of the cam groove of the cam cylinder portion 31. The writing tip of the cursive body 1 has a tip end 21.
It sticks out and becomes a writing state. The state is shown in FIG. When the knocking operation of the knocking member 37 is repeated in this state, the writing tip portion repeatedly appears and disappears from the tip end opening 21. Further, the ink does not leak when the tip ball 10 is in close contact with the inner surface of the chip, but the ink leaks when the tip ball comes into contact with the surface of clothing or the like and is pressed. Further, in the case of low-viscosity ink, since it is sucked into the fiber, the leakage becomes large.

Further, as shown in FIG. 1, the writing tool is fixedly mounted in a chest pocket or the like while the writing tip is retracted from the tip opening 21, and at that time, a stopper piece 39 provided on the knock member is used. The front end 39a of the clip is the base 2 of the clip.
3 is located at the front end, and its front end portion 39a abuts on the upper edge of the pocket. Therefore, when carrying the knock member 3,
Even if an external force is applied to the rear end of 7, the front end 39a of the stopper piece 39 provided on the knock member comes into contact with the upper edge of the pocket to prevent the knock member from advancing. Do not inadvertently project to damage or stain clothing or the human body. Further, when the cursive body is a mechanical pencil, it is possible to prevent the thin tip pipe which is the projecting portion of the core from accidentally projecting and damaging clothes or a human body.

[0021]

As described above, the present invention is mainly equipped with a ballpoint pen writing body using a low-viscosity ink, and the writing tip is locked in a protruding state from the tip opening and in a stored state only by knocking operation. Further, even if an external force is applied to the knock portion carelessly in a state where it is inserted in a chest pocket or the like, a writing instrument in which the writing tip portion does not project and the clothing or human body is not damaged or soiled can be provided at low cost. Further, if the return spring is locked to the front end of the inner hole of the front shaft so that it cannot be removed, the rear shaft can be attached to and removed from the front shaft, and the ballpoint writing system can be replaced very conveniently.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a knock-type writing instrument according to an embodiment of the present invention, showing a state in which a writing body is housed in a shaft.

FIG. 2 is a vertical cross-sectional view showing a state in which a rear end is knocked and a writing front end is projected from a shaft front end.

FIG. 3 is a vertical cross-sectional view of a ballpoint pen cursive body.

[Explanation of symbols]

1 Ballpoint pen cursive 2 cylinders 2a front end 3 front axle 4 Ink storage tube 5 valve chambers 6 ball catch 7 guide hole 8 inner hole 9 chips 10 Tip ball 11 Shaft 12 springs 13 Bar shaft 14 ball valve 15 grooves 16 ink 17 Follower 18 Follower Stick 20 Tip axis 21 Tip mouth 22 Inner section 23 base 24 clips 24a ball part 27 Rear axle 27a inner step 28 Screw part 29 steps 30 Inner hole 31 Cam barrel 33 rotor 34 Cam part 35 knock rod 36 Rear end 37 Knock member 37a groove 38 Locking part 39 Stopper piece 39a front end 39b Mounting part 40 spring 41 Return spring

Claims (4)

[Claims] 1. A cam provided on the rotor, wherein a knock member protruding to the rear end of the shaft cylinder is knocked to move the knock rod back and forth to rotate a rotor provided at the front end of the knock rod. In a knock-type writing instrument configured so that a portion thereof is locked in a forward and backward position in a cam groove provided in the barrel, the barrel has a rear end of a front shaft and a front end of a rear shaft that is detachable. A base portion having a front clip is formed on one side of the rear end of the shaft, and a stopper piece is projectingly provided with one end connected to one side of the knock member. The front end of the is positioned on the front surface of the base in the space formed between the inner surface side of the clip and the outer surface of the rear shaft, and
A knock-type writing instrument characterized in that the front end portion of the stopper piece is configured to advance in a space formed on the inner surface side of the clip as the knock member advances. 2. The knock-type writing instrument according to claim 1, wherein the stopper piece has two legs behind the front end in a state where the base of the clip is sandwiched, and the rear end is fixed to the knock member. 3. The knock-type writing instrument according to claim 1, wherein the front end of the rear shaft is screwed onto the rear end of the front shaft. 4. The tip ball is always brought into close contact with the inner edge of the ball holding portion at the tip of the tip by pressing a spring, the low viscosity ink is filled in the ink containing tube, and the ink is consumed at the rear end of the ink due to writing. The knock-type writing instrument according to claim 1, wherein a ball-point pen writing body filled with a grease-like follower that moves following is arranged at the front end of the rotor.