JP2004268567A - Ballpoint pen of pressurized type - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the problems, such as staining of matters around with ink spurted by pressure, even if an external force is carelessly applied on a tip end when a ballpoint pen is not used. <P>SOLUTION: For the pressurized type ballpoint pen which is provided with an ink holding section, at the rear of the tip, filled with ink and a follower following the ink and a pumping-type pressurizing mechanism at the backward of the former, a press article, which is hooked at the rear end of the shaft tube with a state of forward-movability via a spring, and an expandable/contractable seal tube, having an opening hole at the front end of the tube in front of the press article, are provided. The press article is moved ahead with the state of closing the press-article's vent path communicating with outer air and the seal tube, and the seal of the opening hole is released, at the same time the rear end of the follower is pressurized. The opening hole is sealed again at the front end of the press article by the moving-backward of the press article, at the same time the outer air flows into the seal tube on releasing the closing of of the vent path. The press article is structured such that the article can be hooked on the shaft tube in order to maintain the press article at the state of the utmost-forward movement. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention is a ballpoint pen using an ink that easily runs out of ink in initial writing, a ballpoint pen using an ink that is easy to dry, a ballpoint pen with various fillers mixed in the ink, a handwriting written on the paper surface is easily erased by rubbing with an eraser. The present invention relates to a pressurized ballpoint pen, such as a ballpoint pen filled with erasable ink, a ballpoint pen capable of correcting mistakes and the like by hiding it with white ink, and the like.

JP-A-8-52407 Tokiohei 7-506682 JP-A-2001-121886 Japanese Patent Application Laid-Open No. 2001-150865 Conventionally, a liquid applicator using a white pigment in order to correct a mistake or the like has been known. In addition, since a white pigment and a solvent are easily separated from each other, this type of liquid applicator has a flexible container in which ink, balls, and the like are sealed, and it is necessary to shake and agitate the liquid applicator before use. In addition, the ink is ejected by pressing the side surface of the container. However, when the remaining amount of the ink becomes small, the ink is not ejected even if the side wall of the container is strongly pushed. (Patent Literature 1) Further, there is known an ink which has a shear thinning property and does not need to be stirred. However, there is a problem that the ink flows backward when the ink is applied upward, and the ink easily runs out. (Patent Literature 2) A push body that is protruded from the rear end of the barrel and protrudes from the rear end via a spring so as to be able to move forward with respect to the barrel, and a tubular shape that can expand and contract forward of the push body. The rear end hole of the ink storage tube is communicated with the outside air immediately before the push body advances, and the rear end hole of the ink storage tube is shut off from the outside air at the front end of the seal body immediately after the proper advance. At the same time, the seal body contracts as the push body further advances, and air is pushed into the rear end hole of the ball-point pen refill, and the rear end of the follower is pressed, so that the ink can flow to the tip side. What has been proposed. (Patent Document 3) However, the pressure returns to the atmospheric pressure immediately after the pressurization, and the pressurization is not performed because the pressurization is not continued and the rear end of the follower and the pressurizing mechanism are separated with the consumption of the ink. Therefore, there is a problem that the pressurizing effect cannot be exerted due to the characteristics of the ink due to the decrease of the ink. In addition, a pumping type pressurizing mechanism is provided at the rear end of the barrel, and is located in front of the rear end of a follower arranged so as to be in contact with the rear end of the ink and to follow with the consumption of ink. A valve mechanism is arranged, and air is pushed into the rear end hole of the shaft cylinder by the forward operation of the pressurizing mechanism, and at this time the valve opens at a predetermined pressure and the rear end of the follower is pressurized. There has been proposed one configured to support the flowability of the ink to the chip side. (Patent Document 4) However, this method cannot set an appropriate pressing force due to variations in a valve mechanism (variations in a spring acting on opening and closing of a valve, variations in dimensions of a rubber valve body that elastically opens and closes a slit, and the like). There is a problem. In addition, when the pressing force exceeds a predetermined set value when the ball-point pen is not used, there is a problem in that ink is inadvertently applied to the tip of the writing point and ink is blown out.

In general, ballpoint pens using low-viscosity ink or ink having shear-thinning viscosity have a large amount of outflow of ink (to increase the writing density), and have a large diameter of the ink storage tube to increase the amount of loaded ink. . In addition, since the viscosity of the ink is smaller than that of the oil-based ballpoint pen, the flow resistance to the ink storage tube is small. Accordingly, ink leakage (ink flows backward at the rear end of the ink storage tube) is likely to occur due to the ink's own weight, dropping, or knock impact. For this reason, the ink usually moves following the ink consumption at the time of writing at the rear end of the ink.However, a grease-like follower that suppresses the backflow of the ink against its own weight or impact is provided. A rod is provided immersed in the follower. However, even when the follower is provided, if the ink on the back surface of the ball of the chip is depleted when writing upward, there is a danger that the ink or the head will be added directly, causing a remarkable backflow and soiling the hands and clothes. Further, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink is oozed (DC) when a gap is formed between the tip ball and the tip holding portion when the tip side is directed downward.
In particular, in the case of a liquid applicator that uses a white pigment to correct mistakes, etc., the size at which the tip ball recedes due to pen pressure due to increasing the flow rate of ink or eliminating clogging due to drying. The gap between the peripheral surface of the tip ball and the inner surface of the ball holding portion of the chip is large.

  The present invention is a ballpoint pen that uses ink that is easy to break off during initial writing, a ballpoint pen that is mixed with various fillers in the ink, a ballpoint pen that is filled with ink that can be easily erased by rubbing the handwriting written on the paper with an eraser, It is possible to provide an easy-to-use pressurized ballpoint pen that can be written by concealing mistakes and the like by concealing it with white ink and enabling writing by assisting with a pressing action with a simple structure. Further, it is possible to easily set an appropriate pressing force, and it is possible to avoid a problem that ink is blown out even when an external force is inadvertently applied to the writing tip when the ballpoint pen is not used. In addition, in the case of a ballpoint pen for correcting a typographical error, a white pigment ink containing a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent is formulated to prevent sedimentation of the pigment and not to impair the fluidity. And, by providing a pressure mechanism by pumping, there is no problem that the white pigment and the solvent are separated as in the past, so that there is no need to agitate the ink, and the side of the container is pressed when writing. It is possible to provide a pressurized ballpoint pen for correcting typographical errors which is easy to use and easy to use.

The present invention has the following configurations to achieve the above object.
The pressure-type ball-point pen according to the first aspect of the present invention has a tip of a ball-point pen at the tip, and the rear ink storage portion is filled with ink and the trailing end of the ink with a follower that follows the ink, and further back. In a pressure-type ball-point pen provided with a pumping-type pressure mechanism, a push that is protruded from the rear end of the barrel and is engaged with the barrel through a spring so as to be able to move forward with respect to the barrel. An expandable and contractable seal cylinder having an opening at the front end is provided in front of the body and the push body, and the push body is formed with a ventilation path through which outside air flows into the seal cylinder, and is provided with a seal cylinder. The contact portion is in close contact with the rear end hole of the ink storage portion, the rear end hole is shut off from the outside air, and the opening of the seal cylinder is sealed at the front end of the pushing body, so that the outside air flows into the seal cylinder. Push body forward with air passage closed Accordingly, the inner pressure of the seal cylinder increases due to the contraction of the seal cylinder, and the sealing state between the front end of the push body and the opening of the seal cylinder is released in a state where the push body is further advanced. Air is pushed into the end hole, the rear end of the follower is pressurized, and when the push body is retracted, the opening of the seal cylinder is sealed again at the front end of the push body, and the air passage is closed. It is provided so that outside air flows into the seal cylinder.

  A pressurized ballpoint pen according to a second aspect of the present invention is the pressurized ballpoint pen according to the first aspect, wherein the tip of the ballpoint pen is provided with a tip of the ballpoint pen and an ink storage tube at the rear, and the ink storage tube is filled with ink. A ball-point pen refill having a grease-like follower disposed at the rear end of the ink and following the ink as the ink is consumed is mounted in front of the shaft cylinder. The rear end hole of the ink storage tube (ink storage portion) is provided so as to be shielded from the outside air at the portion.

  A pressure-type ballpoint pen according to a third aspect of the present invention is the pressure-type ballpoint pen according to the first aspect, wherein the push body can be locked to the barrel while the push body is in the most advanced state. It is composed.

  A pressure-type ballpoint pen according to a fourth aspect of the present invention is the pressure-type ballpoint pen according to the first aspect, wherein the front end ball is in close contact with the inner edge of the ball holding portion at the tip end of the tip. , And the ink containing portion is filled with ink that is prevented from sedimentation and that fluidity is not impaired as much as possible.

  The pressure-type ball-point pen according to the fifth aspect of the present invention has a tip of a ball-point pen at the tip, and a rear ink reservoir is filled with ink and a follower that follows the ink at the rear end of the ink. In a pressure-type ball-point pen provided with a pumping-type pressure mechanism, a push that is protruded from the rear end of the barrel and is engaged with the barrel through a spring so as to be able to move forward with respect to the barrel. An extendable seal cylinder having an opening at the front end is provided in front of the body and its pressing body, and the contact portion of the seal cylinder closely contacts the rear end hole of the ink storage unit, and the rear end hole is open to the outside air. At the same time, the seal cylinder is contracted by the advance of the push body, and the air is pushed into the rear end hole of the ink storage unit, so that the rear end of the follower is pressurized. It is configured so that it can be locked against Released to push body is provided so as ambient air to flow into the tubular sealing body with the close contact with the rear end hole of the sealing cylinder and the ink reservoir portion when retracted is released.

In the pressurized ballpoint pen of the present invention, a ballpoint pen using ink that easily runs out of ink during initial writing can be written with the aid of a pressurizing action. In addition, a white pigment ink containing a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and is formulated so that sedimentation of the pigment is prevented and fluidity is not impaired. By providing such a ballpoint pen, there is no problem that the white pigment and the solvent are separated as in the related art, so that there is no need to agitate the ink and there is no need to press the side of the container during writing. It becomes possible.
In addition, the pressurized state can be released when the ballpoint pen is not used, such as when carrying, so that even if external force is inadvertently applied to the writing tip, it is possible to avoid problems such as ink blowing out due to pressurization and soiling the surroundings. It becomes.

1 to 6 show an embodiment of a ballpoint pen according to the present invention.
First, a white pigment ink 9 is filled in the ink storage tube 2 of the ball-point pen refill 1 shown in FIG. 1, and a grease-like follower 10 that follows the ink as the ink is consumed is filled in the rear end of the ink. Further, the follower is not compatible with the ink and has a performance of preventing the evaporation of the ink. A follower rod 11 made of resin having a specific gravity substantially equal to that of the follower is immersed in the follower as needed. (Note that the follower can be a follower such as silicon rubber, for example.)

  Further, the white pigment ink 9 is a white pigment ink containing a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and formulated so as to prevent sedimentation of the pigment and to minimize the loss of fluidity. . In addition, since the ink has a shear thinning property, it is possible to perform coating with a high concealing property in combination with a decrease in the viscosity as the tip ball rotates.

  Further, as shown in the figure, the joint 4 has a front shaft portion 4a formed in front of the flange portion 4b and a rear shaft portion 4c formed in the rear, and holds the tip ball 6 in a chip fitting hole 4d at the tip of the front shaft portion 4a. The shaft 3b of the chip 3 is fixed. A rib 4e is formed at a required location on the outer periphery of the front shaft portion 4a.

  The tip 3 is caulked so that the tip ball 6 is rotatably held with the tip ball 6 substantially in contact with a seat having a channel into which ink can flow. Further, the spring 7 is inserted into the inner hole of the chip 3, the rear end of the shaft 3b of the chip is appropriately caulked, and the rear end of the spring 7 cannot be pulled out.

Further, a linear rod portion 7 a is formed in front of the spring 7, and the tip of the rod portion 7 a contacts the back surface of the tip ball 6 in a pressing manner. The tip ball 6 is brought into close contact with the inner edge of the ball holding portion 3a (formed by caulking or the like) of the chip 3 by the pressing. In addition, it is possible to provide a pressing member for pressing the back surface of the tip ball 6 on the front surface of the spring, or to form the rod shaft portion into an extremely fine coil shape.
Further, it is also possible to form the chip into a resin molded product having excellent abrasion resistance and ink sealing performance, and to provide a spring seat for pressing the back surface of the tip ball as an integral or separate spring seat. is there.

Further, it is extremely important that the tip ball 6 is in close contact with the inner surface of the ball holding portion 3a, even if the ink has a high viscosity, for drying the writing tip and preventing direct current of the ink.
That is, in order to increase the discharge amount of ink, the ballpoint pen for error correction coating as in the present application is set to have a larger retreat size of the tip ball than the ballpoint pen for writing. In addition, grinding of the inner surface to improve the surface roughness of the inner surface of the chip holding the tip ball 6 and close contact accuracy by caulking, and secondary plastic working to increase the caulking accuracy are considered. In addition, if necessary, a surface treatment or the like is taken into consideration for the surface in close contact with the tip ball.

  Further, a valve chamber 5 which is appropriately eccentric with respect to the axis of the chip 3 is provided behind the chip fitting hole 4d, and a tapered or spherical valve body is provided at the rear of the valve chamber 5 so as to communicate with the guide hole 5b. A receiving seat 5a is formed. On one side of the inner wall of the valve chamber 5, a groove 5c into which ink can flow is formed. Further, a spherical valve element 8 is loosely fitted in the valve chamber 5, and the valve element 8 comes into contact with a state where the valve element 8 is biased to the rear end of the shaft portion 3b of the chip with the chip 3 facing downward. The ink flowing from the guide hole 5b through 5c or the like flows into the inner hole of the chip. Note that the valve body may be a shaft-like body having a tapered or spherical surface on the side close to the valve body receiving seat. In this case, it is not necessary to decenter the valve chamber with respect to the chip axis as described above by forming a groove through which the ink flows into the chip on the peripheral surface of the chip that comes into contact with the rear end of the shaft portion of the chip. . In addition, the form of the valve body is not limited to the embodiment.

  FIG. 6 shows another embodiment of the ballpoint pen refill. The difference from the above-mentioned ball-point pen refill 1 is that it does not have a valve element and a follower rod. That is, the valve element and the follower rod are not essential components even as a ballpoint pen for correcting a typographical error. Details will be described later in operation.

  A rear shaft portion 4c extends behind the flange 4b of the joint 4. On the outer periphery of the rear shaft portion 4c, a cylindrical ink storage tube 2 is press-fitted and fixed by contacting the front end thereof to the rear end of the flange portion 4b, and the inner diameter portion of the ink storage tube 2 is conducted to the guide hole 5b of the joint 4. I have. The ink storage tube 2 is made of, for example, a transparent PP resin molded product. In the ballpoint pen of the above-described embodiment, the joint and the ink storage tube are formed as separate members, but both can be formed as an integrated resin molded product.

Next, FIG. 2 and FIG. 3 show an embodiment of a ballpoint pen as an applicator in which the ballpoint pen refill 1 is mounted on a shaft main body. The shaft body is mainly composed of a cap 17, a shaft cylinder 15, a mouth portion 16, and a push body 12.
First, as shown in the drawing, the shaft cylinder 15 is a resin molded product, and has a detachable lip portion 16 on the front side thereof, and an engaging portion comprising a protrusion and a groove portion on the outer periphery slightly rearward, and an engaging portion. At the rear end, a step portion with which an end portion of a cap 17 described later abuts is formed. Further, a step 16a is formed on the peripheral surface of the inner hole of the mouth portion 16.
The ball-point pen refill 1 is inserted from the front end of the barrel 15, the rear end of the flange 4 b of the joint 4 abuts on the front end of the barrel 15, and the lip 16 is joined to the outer periphery of the front end of the barrel by screwing or the like. Then, the rib 4e provided on the outer periphery of the joint 4 engages with the step 16a of the lip, and the tip of the tip 3 projects from the tip hole of the lip 16.

On the other hand, at the rear end of the shaft cylinder 15, a pressurizing mechanism section comprising a pressing body and a seal cylinder is provided. A step 15c is formed in the rear end hole of the shaft cylinder 15.
First, the push body 12 has a step portion 12a at the front, a flange portion 12b at the front, a shaft portion 12c and a guide portion 12d at the front thereof, and furthermore, the push body 12 has a front end from the rear end. An air hole 12e is provided, and an air inlet 12f is formed at the front end of the air hole 12e on the side surface of the guide portion 12d. Further, a rear end portion of the seal body 13 having a cylindrical portion that can expand and contract in the axial direction is fixed to the outer periphery of the shaft portion 12c.

The seal cylinder 13 is made of an elastic body such as rubber as an example, has a slightly thick front portion, is provided with a contact portion 13a at the front end, and further has an opening 13c communicating with the inside at the front end. Further, the elastic portion 13b is provided in a slightly thin cylindrical shape on the rear side, and the cylindrical portion can be expanded and contracted in the axial direction.
The guide portion 12d has a seal portion 12g which is slightly bulged in the radial direction at its front end so that the opening 13c of the seal cylinder is sealed, and when the seal cylinder 13 expands and contracts. It also has a function of guiding the seal cylinder so as not to be laterally deformed.
In addition, the sealing cylinder 13 can also be formed as a resin molded product in which the cylindrical portion has a bellows shape that can be freely extended and contracted. Further, a spring can be laid between the pushing body and the seal body inside or outside the seal cylinder so that the seal cylinder always keeps the extended state. (Not shown)

The push body 12 is inserted from the rear end of the barrel 15, and a spring 14 is laid between the step 12 a of the push body and the rear surface of the step 15 c of the barrel, and the flange 12 b is attached to the front of the step 15 c. The pushing body 12 is constantly urged rearward with respect to the shaft cylinder 15 by the spring 14. Further, the contact portion 13a of the seal cylinder 13 is in close contact with the edge of the rear end hole of the ink storage tube 2 of the ballpoint pen refill, so that the rear end hole of the ink storage tube is shut off from the outside air.
Further, as shown in FIG. 5, a protrusion 12 h is provided on the side surface of the push body 12, while a hook-like groove 15 d is provided on the side surface of the shaft cylinder 15, and the push body 12 is in the most advanced state. And can be locked to the shaft cylinder 15. The contents will be further described in the section of operation.

The cap 17 fitted to the front end of the shaft cylinder 15 is a resin molded product having excellent elasticity. The clip 15b is positioned on the outer peripheral side surface of the cap 17 and the cylinder at the rear end is pressed against the rear end hole of the cap. . In addition, a ventilation hole penetrates through the rear end of the cylindrical portion of the clip.
A cylindrical inner cap 17a having a small chamber is provided behind the inner hole of the cap 17, and the inner cap 17a is integrally connected to the cap inner hole by a required number of ribs. As described above, a ventilation path communicating with the ventilation hole from the cap insertion port is formed between the ribs, and serves as a secure ventilation means in the event that an infant swallows the cap. Further, a seal stopper 18 made of a non-liquid-absorbing, non-continuous-cell elastic body is fixed to the tip of the small chamber of the inner cap 17a. When the cap is fitted, the tip 3 and the tip 16 have the tip. The tip of the tip is closely contacted with the seal plug 18 while being substantially fitted in the small chamber.

The sealing means between the front end of the pressing body and the opening of the sealing cylinder is not limited to the above-described embodiment.
In the above-described embodiment, the ball-point pen refill is mounted on the front of the barrel. However, the front part of the barrel can be provided directly with the tip of the ball-point pen and the ink storage part on the rear side. it can. In addition, the barrel is divided into a front part and a rear part, and the barrel is made detachable by screwing or the like, and the front part of the barrel is directly provided with a ballpoint pen tip at the tip and a ballpoint refill having an ink storage part at the back. It is possible to

Next, the operation of the embodiment will be described below.
First, as shown in FIG. 3, the contact portion 13a of the seal cylinder 13 is in close contact with the edge of the rear end hole of the ink storage tube 2, and the inner hole of the ink storage tube is sealed. When the pushing body 12 is pumped (pressing forward operation) with the rear end of the ventilation hole 12e sealed with a finger, the sealing cylinder 13 contracts to increase the internal pressure of the sealing cylinder. The sealing state between the seal portion 12g provided at the front end of the body and the opening 13c of the seal cylinder 13 is released, air is pushed into the rear end hole of the ink storage tube 2, and the rear end of the follower 10 is pressurized. Thus, the fluidity of the ink to the chip side is supported. This has the effect of preventing ink from separating from the peripheral surface of the tip ball due to drop impact and poor ink fluidity, etc. Become. (See Fig. 4)

When the pressing of the pressing body 12 is released, the pressing body 12 retreats, and the opening 13c of the sealing cylinder 13 is sealed again by the seal portion 12g provided at the front end of the pressing body.
Subsequently, when the finger is released from the rear end of the ventilation hole 12e, outside air flows into the seal cylinder 13 and returns to the original state. Therefore, by repeating the pumping, air is sequentially pushed into the rear end hole of the ink storage tube 2, the rear end of the follower 10 is maintained in a pressurized state, and the fluidity of the ink to the tip side can be continuously supported. Become.
Further, the pressing force is determined by the contracting volume of the seal cylinder and the sealing performance between the seal portion of the pressing body and the opening of the seal cylinder, and the material and dimensions of the seal cylinder and the shape of the seal portion are set. In addition, the internal pressure does not rise excessively and leaks from the seal portion.

In addition, when the push body 12 is rotated to one side with respect to the barrel 15 in the state shown in FIG. 4, a protrusion 12 h provided on the side face of the push body 12 is formed into a hook-like shape provided on the side face of the barrel 15. Engagement with the horizontal groove of the groove 15d prevents the push body from retreating even if the advance of the push body is released. Therefore, the rear end of the follower 10 is maintained in a state of communicating with the outside air.
In the pumping operation for pressurizing, the protrusion 12h reciprocates in the vertical groove of the groove 15d. The means for locking the pusher at the forward / backward retracted position is not limited to the above-described embodiment, but a well-known locking means such as a knock mechanism for locking the writing tip of the ballpoint pen so that it can protrude and retract from the shaft tip. Applicable.

Next, the operation of the ballpoint pen refill will be described.
FIG. 1 shows a state in which the tip 3 is turned upward, and the backflow of ink is prevented because the tip ball 6 is brought into close contact with the inner edge of the tip holding portion 3a by the pressing of the rod 7a of the spring 7. . Also, at this time, since the valve element 8 is positioned at the valve element receiving seat 5a of the valve chamber 5 and seals the guide hole 5b, even if the ink is written upward and the ink on the back surface of the tip ball 6 of the chip runs out, the ink is applied to the head. No backflow. Therefore, when the tip 3 is turned downward, the ink can immediately flow out.
By the way, in the structure without the ball valve, when the upward writing is repeated, the ink acts in the backward flow direction, so that air is entrapped in the chip, and the ink tends to be hardly immediately discharged in the downward writing. The follower rod 11 is used when the ink storage tube has a large diameter. That is, the grease-like follower 10 has a problem that when the ink container tube has a large diameter, the ink container tube is easily deformed and broken by the influence of impact or the like. In this case, it is possible to increase the rigidity by immersing a resin-made follower rod having substantially the same specific gravity as the follower in the follower.

  In a writing state in which the tip 3 is directed downward, the valve element 8 abuts on one of the rear ends of the tip in a state of being biased, and the other end has a groove portion 5c through which ink can flow into the tip 3. The ink 9 that has entered the valve chamber 5 from the ink storage tube 2 through the guide hole 5b is guided to the back surface of the tip ball 6 of the chip 3 through the groove 5c.

In this state, the tip ball 6 is brought into close contact with the inner edge of the tip holding portion 3a by the pressing of the rod shaft portion 7a of the spring 7, so that the direct current of the ink is prevented.
In addition, since the tip ball 6 retreats due to the writing pressure, a gap is generated and ink can flow out. With the help of the pressurizing action, the ink flows out by rotation of the tip ball 6 by writing, and erroneous writing and the like are concealed by the ink. You.
In the case of correcting a typographical error, the tip ball retreats greatly, so it is important that the tip ball immediately contact the inner edge of the chip holding portion by pressing the spring even if the rear end side of the ink is pressed.

  The above-described ink backflow prevention structure having a follower rod and a valve element exhibits performance when the ink storage tube has a large diameter and easily flows back, or when repeated upward writing or when an impact is applied. It is not essential as a component, and a ballpoint pen for correcting clerical errors is not necessarily used because it is rarely used upward. Other than ink for correcting a typographical error, a spring for pressing the back surface of the tip ball may not always be required for one having a considerably high ink viscosity and a small amount of retreat of the tip ball.

7 and 8 show the rear half of a ballpoint pen according to another embodiment of the present invention. The seal cylinder body 21 is also made of an elastic body such as rubber as an example. The contact part 21a is provided at the front end with a slightly thick front part, and the elastic part 21b is provided at the rear part with a slightly thin cylindrical shape. The tubular portion is made to be able to expand and contract in the axial direction. The guide portion 20d is provided to guide the seal cylinder so as not to be laterally deformed when the seal cylinder 21 expands and contracts, and is not essential. In addition, the sealing cylinder 21 can be formed as a resin molded product having a tubular portion whose bellows shape can be freely extended and contracted.
Further, a spring can be laid between the pushing body and the seal body inside or outside the seal cylinder so that the seal cylinder always keeps the extended state. (Not shown)

The push body 20 is inserted from the rear end of the barrel 15, and the spring 14 is laid between the step 20 a of the push body and the rear face of the step 15 c of the barrel, and the flange 20 b is attached to the front of the step 15 c. The pushing body 20 is constantly urged rearward with respect to the shaft cylinder 15 by the spring 14. Further, the contact portion 21a of the seal cylinder 21 is in contact with the edge of the rear end hole of the ink storage tube 2 of the ballpoint pen refill with a slight gap, so that the rear end hole of the ink storage tube communicates with the outside air. .
That is, the rear end hole of the ink storage tube 2 is communicated with the outside air immediately before the push body 20 advances, and the rear end hole of the ink storage tube is shut off from the outside air and pressurized immediately after the ink storage tube 2 is appropriately advanced. It is configured as follows.

  In the case of this embodiment, first, the pushing body 20 is pumped (advancing operation), and when the contact portion 21a of the seal cylinder 21 contacts the edge of the rear end hole of the ink storage tube, the inner hole portion of the ink storage tube is started. Is closed, and when the pressing body 20 further advances, the rear end hole of the ink storage tube is shut off from the outside air and pressurized. Therefore, the rear end of the follower is pressurized by the air being pushed in, thereby supporting the flow of the ink toward the chip. Further, in this state, the pressurized state is maintained by locking the push body in the advanced state. By releasing the locked state, the rear end of the follower becomes the same as the outside air.

  Further, the present invention can be extended to a knock-type writing instrument in which a writing tip portion protrudes and protrudes from an axis. For example, the shaft cylinder 15 of the above-described embodiment is provided as a knock cylinder so as to reciprocate on the shaft body of the knock-type writing instrument, a ball-point pen refill is mounted so as to be integrated with the knock cylinder, and the ball-point pen refill is pressed when pressurized. This can be achieved by configuring the rear end hole so as to be in close contact with the contact portion of the seal cylinder.

FIG. 2 is a vertical cross-sectional view showing the entire ballpoint pen refill used in the present invention, showing a state in which a chip is directed upward. FIG. 4 is an enlarged cross-sectional view of a front half of the ballpoint pen of the present invention, showing a state where a cap is fitted to a front end of a barrel. It is sectional drawing to which the rear half part of the ball-point pen of this invention was expanded. It is sectional drawing to which the rear half part of the ball-point pen in the state where it pumped was expanded. It is a figure showing the state where it was locked to the barrel in the state where the pushing body advanced most. It is a longitudinal cross-sectional view which shows the whole ballpoint pen refill of another form used for this invention. It is sectional drawing to which the rear half part of the ball-point pen which is another Example of this invention was expanded. It is sectional drawing to which the rear half part of the ball-point pen of the pumping state of another Example was expanded.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Ball-point pen refill 2 Ink storage tube 3 Tip 3a Ball holding part 3b Shaft part 4 Joint 4a Front shaft part 4b Flange part 4c Rear shaft part 4d Chip fitting hole 4e Rib 5 Valve chamber 5a Valve seat 5b Guide hole 5c Groove part 6 Tip Ball 7 Spring 7a Rod Shaft 8 Valve 9 Ink 10 Follower 11 Follower Rod 12 Pusher 12a Step 12b Flange 12c Shaft 12d Guide 12e Vent 12f Inlet 12g Seal 12h Projection 13 Seal Tube 13a Contact portion 13b Elastic portion 13c Opening hole 14 Spring 15 Shaft tube 15a Shaft portion 15b Clip 15c Step portion 15d Groove portion 16 Tip 16a Step 17 Cap 17a Inner cap 18 Seal plug 20 Press body 20a Step 20b Flange 20c Shaft 20d Guide 21 Seal cylinder 21 Abutment portion 21b elastic portion

Claims (5)

A pressure-type ball-point pen with a ball-point pen tip at the tip, a back ink reservoir filled with ink and a follower that follows the ink at the rear end of the ink, and a pumping-type pressure mechanism provided further behind it. At
At the rear end of the barrel, a push body that protrudes from the rear end and is engaged with the barrel via a spring so as to be able to move forward, and an extensible seal having an opening at the front end in front of the push body. A cylinder is provided, and the pusher is provided with a ventilation path through which outside air flows into the seal cylinder. The contact portion of the seal cylinder closely contacts the rear end hole of the ink storage unit, and the rear end hole is open to the outside air. And at the front end of the push body, the opening of the seal cylinder is sealed, and the push body advances by the push body in a state where the ventilation path of the push body through which outside air flows into the seal cylinder is closed. The sealing member is contracted to increase the internal pressure of the seal cylinder, and in a state where the push body is further advanced, the sealing state between the front end of the push body and the opening of the seal cylinder is released, and air is supplied to the rear end hole of the ink storage unit. When the pusher is pushed in and the rear end of the follower is pressed, In the an opening hole of the tubular sealing member is sealed, air passage pressurized ballpoint made provided such that the outside air into the tubular sealing body flowing by releasing the occlusion.   A ballpoint pen refill equipped with a ballpoint pen tip at the tip and an ink storage tube at the rear, and a grease-like follower that fills the ink storage tube with ink and follows the ink as the ink is consumed at the rear end. 2. A ball-point pen mounted in front of a shaft cylinder, wherein a rear end hole of an ink storage tube (ink storage section) is shielded from outside air at a contact portion of a seal cylinder. 2. A pressurized ballpoint pen according to item 1.   The pressurized ball-point pen according to claim 1, wherein the push body is configured to be able to be locked to the barrel while the push body is in the most advanced state.   A spring pressure is applied to the back surface of the tip ball so that the tip ball is in close contact with the inner edge of the ball holding portion at the tip of the tip, and sedimentation is prevented in the ink storage portion and the fluidity is minimized. The pressurized ballpoint pen according to claim 1, wherein the ink is filled with the compounded ink. A pressure-type ball-point pen with a ball-point pen tip at the tip, a back ink reservoir filled with ink and a follower that follows the ink at the rear end of the ink, and a pumping-type pressure mechanism provided further behind it. At
At the rear end of the barrel, a push body that protrudes from the rear end and is engaged with the barrel via a spring so as to be able to move forward, and an extensible seal having an opening at the front end in front of the push body. A cylindrical body is provided, and the contact portion of the seal cylindrical body is in close contact with the rear end hole of the ink storage unit, the rear end hole is shut off from the outside air, and the seal cylindrical body contracts due to the advance of the push body, and the ink is stored. The rear end of the follower is pressurized by the air being pushed into the rear end hole of the section, and the push body is configured to be able to be locked to the shaft cylinder in the advanced state. A pressurized ballpoint pen provided so that when the body is retracted, the close contact between the seal cylinder and the rear end hole of the ink container is released, and outside air flows into the seal cylinder.

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