JP2005066961A - Ball-point pen of pressurizing type - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a ball-point pen using an ink which is apt to easily break off a normally writing pen with the assistance of a simple pressurizing mechanism. <P>SOLUTION: The ball-point pen of a pressurizing type is structured of a tip of the ball-point pen installed at the apex; an ink accommodated in a backward ink accommodating tube; a follower packed at the rear end of the ink; and a pumping-type pressurizing mechanism housed inside the ink accommodating tube or the inner hole of a barrel integrally provided at the rear end of the ink accommodating tube behind the follower. In the pumping-type pressurizing mechanism, a valvular mechanism part which has a venting hole where the rear end of the follower communicates with an open air by the deformation of the elastic body having fine interconnected pores at the rear end of the follower by an outer force, while the rear end part of the follower is always airtightly closed to the open air; and a knocking mechanism part with a knocking bar fitted thereto, formed behind the valvular mechanism part in such a state that the knocking mechanism part is always urged backward by a knocking spring, are provided. Thus the elastic body is deformed by the outer force to be inflicted by the knocking bar in such a state that a space part is appropriately compressed by moving the knocking bar forward. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a ballpoint pen that uses ink that is easy to run out of ink during initial writing, a ballpoint pen in which various fillers are mixed 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, The present invention relates to a pressure-type ballpoint pen that can be corrected by concealing an error or the like with white ink.

JP-A-8-52407 7-506862 JP, 2001-150865, A Conventionally, the liquid applicator using a white pigment in order to correct mistakes etc. is known. In addition, since the white pigment and the solvent can be easily separated, this type of liquid applicator has a flexible container filled with ink, balls, and the like, and needs to be shaken and stirred in use. Further, the ink is ejected by pressing the side surface of the container. However, when the remaining amount of ink decreases, there is annoyance that the ink is not ejected even if the side wall of the container is strongly pressed. (Patent Document 1) In addition, there is a known ink that does not need to be agitated by using ink having shear thinning viscosity, but there is a problem that the ink tends to run out of ink when applied upward. (Patent Document 2) Further, a pumping-type pressurizing mechanism portion is provided at the rear end of the shaft cylinder, and a follower arranged to follow the ink exhaustion in front of it and in contact with the rear end of the ink. A valve mechanism is disposed at the rear end, and air is pushed into the rear end hole of the shaft cylinder by the forward movement of the pressurizing mechanism, and at that time, the valve opens at a predetermined pressure and the rear end of the follower is added. There has been proposed one configured to support the fluidity of the ink toward the tip side by being pressed. (Patent Document 3) However, in this case, it is not possible to set an appropriate pressurizing force due to variations in the valve mechanism (such as variations in the spring acting on the opening and closing of the valve, and variations in the size of the rubber valve element that elastically opens and closes the slit). There is a problem. Further, when the applied pressure exceeds a predetermined set value, the ballpoint pen is not used, and there is a problem that an external force is inadvertently applied to the writing tip and ink is ejected.

In general, ballpoint pens that use low viscosity ink or ink with shear thinning viscosity have a large ink outflow (to increase the writing density), and the diameter of the ink containing tube is increased to increase the amount of ink loaded. . Further, since the viscosity of the ink is smaller than that of the oil-based ballpoint pen, the flow resistance with respect to the ink containing tube is small. Therefore, ink leakage (ink flows backward at the rear end of the ink containing tube) is likely to occur due to the weight of the ink, dropping or knocking impact. For this purpose, the ink usually moves following the ink consumption at the time of writing at the trailing edge of the ink, but a grease-like follower that suppresses the back flow of the ink against the ink's own weight or impact is also available. A rod is provided immersed in the follower. However, even if the follower is provided, when writing is performed upward, if the ink on the back side of the ball of the chip runs out, the ink head is added directly, so that there is a risk of causing a significant back flow and soiling hands and clothes. In addition, since the viscosity of the ink is low and the amount of outflow is large, there is a problem that the ink oozes out (direct current) when a gap is formed between the tip ball and the tip holding portion when the tip side is faced downward.
In particular, in the case of liquid applicators that use white pigments to correct errors, etc., the size that the tip ball retracts due to pen pressure due to reasons such as increasing the ink flow rate and eliminating clogging due to drying. The clearance 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 ink in the initial writing, a ballpoint pen in which various fillers are mixed 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, A ballpoint pen that can be corrected by concealing misprints etc. with white ink is supported by a pressurizing action and can be written. Mainly contains white pigments such as titanium oxide and polymer hollow fine particles and gelling agents, white pigment ink formulated to prevent precipitation of the pigments and fluidity, and pressurizing mechanism by pumping By providing, there is no problem that the white pigment and the solvent are separated as in the prior art, and therefore there is no need to stir the ink, and there is no need to press the side of the container during writing. A ballpoint pen can be easily provided with an appropriate pressure. Also, especially when the applied pressure exceeds the preset value, it is possible to avoid the problem that the ink is blown out due to an external force being applied to the writing tip inadvertently because it is left unused. To do.

The present invention has the following configuration in order to achieve the above-described problems.
The pressure type ballpoint pen according to the invention of claim 1 comprises a tip of a ballpoint pen at the tip and an ink storage tube at the back, and the ink storage tube is filled with ink and a follower that follows ink at the rear end of the ink, Further, in the pressurization type ballpoint pen in which a pumping type pressurizing mechanism is provided in an inner hole of a cylindrical body provided so as to be integrated with a rear end of the ink containing pipe or the ink containing pipe, the pumping The pressurizing mechanism of the type is provided with an elastic body with fine continuous pores at a position facing the rear end of the follower, and the rear end of the follower is normally sealed with the outside air, and the elastic body is deformed by external force. As a result, the rear end of the follower is formed with a vent that communicates with the outside air, and the rear of the valve mechanism is rearwardly pushed by a knock spring so that it can be moved forward and backward. And a knock mechanism portion formed by compressing a space portion formed between the vent and the front end of the knock rod when the rod bar is advanced, and the space portion is appropriately moved by advancing the knock rod. In a compressed state, the elastic body is configured to be deformed by receiving an external force from a knock bar.

  The pressure-type ballpoint pen according to the invention described in claim 2 is the pressure-type ballpoint pen according to claim 1, wherein the required number is a slit portion that becomes a vent on the bottom surface of the elastic body or is normally closed. The slit portion is normally sealed and the rear end of the follower is in a closed chamber state, and the front end of the knock bar is provided with a convex portion so that the space can be appropriately moved by moving the knock bar forward. In the compressed state, the slit portion or the minute hole is configured to be expanded by an external force by the convex portion.

  The valve mechanism portion is provided with a cylindrical body having a vent hole that communicates only with the rear end side of the follower at a position facing the rear end of the follower, and an elastic body is provided so as to seal the vent hole. In the state where the knock bar is advanced and the space portion is appropriately compressed, the elastic body is deformed by an external force by a convex portion provided at the front end of the knock bar so that the vent hole is opened.

  There are various forms of the pressure ballpoint pen of the present invention. The pressure-type ballpoint pen can be used as a refill for a knock-type writing instrument, or a cap-type writing instrument in which the writing tip is covered with a cap. There are also various forms of the valve mechanism of the pumping type pressurizing mechanism.

  According to the present invention, a ballpoint pen using ink that is likely to run out of ink in the initial writing can be written with the aid of the pressing action. In addition, it contains white pigments such as titanium oxide and polymer hollow fine particles, and a gelling agent. The white pigment ink is formulated so that the precipitation of the pigment is prevented and the fluidity is not impaired. By providing, there is no problem that the white pigment and the solvent are separated as in the prior art, so there is no need to stir the ink, there is no need to press the side of the container during writing, and the troublesome cap attachment / detachment It is possible to provide a knock-type writing instrument for correcting errata that is easy to use. Also, especially when the applied pressure exceeds a predetermined set value, it is possible to avoid the problem that the ink is not used and the ink is blown out by inadvertently applying external force to the writing tip. .

  FIGS. 1 to 5 show a state where the ballpoint pen 5 according to the first embodiment is mounted on a knock-type writing instrument as a refill. This knock type writing instrument has a shaft cylinder 1 having a long axial hole 1d that opens from the rear end edge to a front position at a required distance in a part of the side circumference by opening the front end and the rear end, A ball portion 1b that is elastically displaceable in the upward and lateral directions is provided at a position facing the window hole 1d of the shaft tube 1, and the ball portion 1b is provided with a locking step portion 1c. A clip 1a having a base portion 1e joined to the tube 1 is integrally formed of resin, and the upper end of the U-shaped base portion 1e having an open front end is formed as an elastic piece 1f surrounded by a slit. An inclined surface 1g is appropriately formed at the lower end of 1f. A front shaft 2 is detachably fixed to the front end of the shaft tube 1 by means such as screwing.

  On the other hand, although the details will be described later, the return spring 4 is inserted into the shaft cylinder 1 from the rear end opening of the shaft cylinder 1 with the return spring 4 fitted to the front shaft section 6a of the joint 6 of the ballpoint pen. The front end is in contact with the inner step portion 2 c of the front shaft 2, and the rear end is in contact with the step portion 6 e of the joint 6.

The knock cylinder 3 is a cylinder on the front end opening and the rear end closing, and a locking projection 3a, a rib 3b, and a safety piece 3c are integrally formed from the front on the coaxial line of the outer peripheral portion.
The knock cylinder 3 is inserted from the rear end of the shaft cylinder 1 in a state where the ink containing tube 10 of the ballpoint pen 5 is fitted in the inner hole thereof, and the locking protrusion 3a, the rib 3b, and the safety piece 3c are connected to the shaft cylinder 1. The rear end of the safety piece 3c is brought into contact with the step 1h of the front end of the elastic piece 1f provided on the base 1e of the clip 1a, and is prevented from coming off.

  As described above, when the rear end of the knock cylinder 3 is pressed forward, the locking projection 3a pushes up the ball 1b of the clip 1a and moves forward so that the ballpoint pen is positioned to engage with the locking step 1c. 5 tips 7 protrude from the tip hole 2 a of the front shaft 2. (Refer to FIG. 2) The tip of the clip 1a is elastically displaced slightly upward or laterally to release the engagement between the locking step 1c and the locking projection 3a, and the ballpoint pen 5 is attached to the safety piece by the return spring 4. The dimensions of each part are appropriately set so that the tip 7 of the ballpoint pen 5 is immersed inside the front shaft 2 in a state in which the tip 7 of the ballpoint pen 5 is retracted until it hits the step 1h of the elastic piece 1f. The ballpoint pen 5 is replaced with the tip shaft 2 removed from the shaft barrel 1, but in the case of a single use in which the ballpoint pen 5 is not replaced, the shaft barrel 1 and the tip shaft 2 can be formed integrally.

3 to 5 show the ballpoint pen 5 described above.
First, as shown in FIG. 3, the ink containing tube 10 of the ballpoint pen 5 is filled with low-viscosity ink or ink having shear thinning, mainly white pigment ink 11, and the ink is consumed at the rear end of the ink. In addition, a grease-like follower 12 that follows the ink is filled.
Further, the follower 12 is incompatible with ink and has a performance of preventing ink evaporation. Further, a resin-made follower rod having a specific gravity substantially equal to that of the follower is immersed in the follower 12 as necessary. The follower may be a follower such as silicon rubber.

  The white pigment ink 11 is a white pigment ink that contains at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent and is blended so that the precipitation of the pigment is prevented and the fluidity is not impaired as much as possible. . In addition, since the ink has shear thinning viscosity, it can be applied with high concealability in combination with a decrease in viscosity due to rotation of the tip ball.

  The joint 6 has a front shaft portion 6a formed in front of the flange portion 6b and a rear shaft portion 6c formed in the rear, and the shaft portion of the tip 7 holding the tip ball 8 in the tip fitting hole 6h at the tip of the front shaft portion 6a. 7a is fixed. The tip 7 is crimped so that the tip ball 8 is rotatably held in a state where the tip ball 8 is substantially in contact with a seat having a channel through which ink can flow. Further, a spring 9 is inserted into the inner hole portion of the tip 7, and the rear end of the shaft portion 7a of the tip is appropriately crimped so that the rear end of the spring 9 cannot be pulled out.

Further, a linear rod shaft portion 9 a is formed at the tip of the spring 9, and the tip of the rod shaft portion 9 a is in contact with the back surface of the tip ball 8 in a pressed state. Further, the tip ball 8 is in close contact with the inner edge of the ball holding portion (formed by caulking or the like) of the chip 7 by the pressing.
It is possible to provide a pressing member for pressing the back surface of the tip ball 8 on the front surface of the spring, and it is also possible to form the rod shaft portion in a coil shape with a very thin winding. Furthermore, the tip can be made of a resin molded product with excellent wear resistance and ink sealing performance, and the spring seat that presses the back of the tip ball can be configured as an integral or separate spring seat. is there.

Further, it is extremely important for the tip ball 8 to be in close contact with the inner surface of the ball holding portion for drying the writing tip and preventing direct current of the ink even if the ink has a high viscosity.
That is, in the ballpoint pen mainly for correcting correction of writing as in the present application, in order to increase the amount of ink discharged, the size of the tip ball to recede is set larger than that of the ballpoint pen for writing. In addition, the surface roughness of the inner surface of the chip holding the tip ball 8 as necessary, the inner surface is ground to improve the crimping accuracy, and the secondary plastic processing is performed to increase the crimping accuracy. The In addition, surface treatment or the like is considered on the contact surface with the tip ball if necessary.

  In order to prevent ink backflow, a valve chamber is provided behind the tip fitting hole 6d, and a tapered or spherical valve body receiving seat is formed at the rear of the valve chamber to communicate with the rear. A spherical valve element is loosely fitted in the valve chamber, and the guide hole is closed with the tip 7 facing upward to prevent backflow of the ink. It is possible to configure so that the ink flows into the chip inner hole by restricting the end holes not to be closed. The valve body may be a shaft-shaped body having a tapered or spherical surface on the side close to the valve body seat.

  In addition, a rear shaft portion 6c extends behind the collar portion 6b of the joint 6, and a cylindrical ink containing tube 10 is brought into contact with the rear end of the collar portion 6b on the outer periphery of the rear shaft portion 6c. It is press-fit. The ink containing tube 10 is made of, for example, a transparent PP resin or nylon resin molded product. Further, in the embodiment, the joint and the ink storage tube are formed as separate members, but it is also possible to form both of them as an integral resin molded product.

  A pumping type pressurizing mechanism is provided at the rear end of the ink containing tube 10. The configuration will be described below.

The pumping type pressurizing mechanism is composed of a valve mechanism part in which the inside of the ink containing tube is closed and a knock mechanism part provided so as to compress a space part formed behind the valve mechanism part. Has been.
First, the valve mechanism is disposed at the rear end of a follower that is disposed so as to contact the rear end of the ink and follow the ink as it is consumed.

In the embodiment, the valve mechanism is configured as follows.
First, the bush 13 is an elastic body made of, for example, rubber or soft resin, and is fixed to a predetermined position of the inner hole of the ink containing tube 10 with a cylindrical body having a bottom surface 13d whose front end is closed. Moreover, the slit part 13c is provided in the required place from the bottom face 13d to the axial direction of a back peripheral surface at the cylindrical body. Further, a stepped portion 13b (tapered or the like) is formed in the inner hole 13a of the bush 13, and a metal or resin spring body 14 is fitted to the front outer periphery of the cylindrical portion.

A knock mechanism is disposed behind the valve mechanism.
A tapered slit portion 10b is formed on the side surface of the rear end portion of the ink containing tube 10 so as to become narrower from the rear end side toward the front. The slit portion 10c has a step portion 10c at the front end and has a predetermined length in the axial direction. 10a is formed.
Further, the knock bar 15 is formed with a collar portion at the rear end and a shaft portion in front thereof, a step portion 16b is provided at the front end of the collar portion, and the projection 15a and the shaft portion outer periphery approximately in the middle of the shaft portion outer periphery. A circumferential groove portion 15c is provided at the front end, and a seal ring 16 made of an elastic body such as rubber or an elastic molding resin is fixed to the groove portion 15c as an example. The seal ring 16 is selected to have good airtightness and slipperiness. In addition, other lubricants are taken into consideration. Further, the seal ring portion can be integrally formed on the outer periphery of the shaft portion.

  The knock bar 15 is inserted from the rear end of the ink containing tube 10, a knock spring 17 is laid between the step portion 15b and the rear end of the ink containing tube 10, and the protrusion 15a has the tapered shape. The slit portion 10b is elastically expanded, the protrusion 15a is locked to the front surface of the step portion 10c, and the knock bar 15 is always urged rearward with respect to the ink containing tube 10 by the knock spring 17. Further, the shaft part front of the knock bar is fitted into the rear end hole of the ink containing tube 10, and the outer peripheral part of the seal ring 16 is in sliding contact with the inner peripheral part of the rear end hole. At that time, the seal ring 16 is located in a state immediately before the front end of the slit portion 10a. Therefore, the space 18 formed between the rear end of the seal member 14 and the front end of the knock bar 15 is It communicates with the outside air. That is, immediately before the knock bar 15 is moved forward, the space 18 of the ink storage tube 10 is communicated with the outside air, and immediately after the knock bar 15 is properly advanced, the outer peripheral portion of the seal ring 16 is the inner peripheral portion of the ink storage tube 10. By being in close contact with the outside air, it is cut off from the outside air and pressurized as the space 18 is reduced. The knock mechanism is configured as described above.

  Further, in a state where the knock bar 15 is advanced and the space portion 18 is appropriately compressed, the convex portion 15d provided at the front end of the knock bar 15 contacts the step portion 13b formed in the inner hole of the bush 13, and further advances. As a result, the front of the cylindrical body is expanded against the tightening of the spring body 14, and the slit 13c on the bottom surface 13d is opened to form a vent hole (see FIG. 5). Flows into the rear end of the follower 12.

6 to 9 show a ballpoint pen that is a second embodiment and a third embodiment.
First, the ballpoint pen 19 shown in FIGS. 6 and 7 includes a shaft cylinder 20, a tip 25, a valve body 24, a receiving seat member 22, an ink 28, a follower 29, a follower rod 30, and a pumping-type additive provided at the rear end of the shaft cylinder. The ballpoint pen 37 shown in FIGS. 8 and 9 is configured by removing the valve body, the receiving seat member, and the follower rod, both of which are arranged on the front shaft portion 21 as the final form of the writing instrument. A cap (not shown) to be fitted is provided.

  The shaft cylinder 20 is a resin molded product (usually a transparent resin), and integrally has a tapered tip shaft portion 21 at the tip. In addition, an inner hole 21a is formed from the tip, and there is a widened hole (becomes the valve chamber 23) at the rear end of the inner hole, and ribs 21c are provided radially at a plurality of locations at the front end of the hole.

On the other hand, the receiving seat member 22 has a tapered or spherical valve body receiving seat 22a on the front surface, and is provided with a guide hole 22d penetrating from the center of the valve body receiving seat 22a to the rear end.
Further, a convex portion 22b is formed in a circumferential shape in front of the outer peripheral portion, and a circumferential or protruding locking portion 22c is formed in the rear.
The seat member 22 is inserted from the rear end of the shaft tube 20 and is positioned in contact with the step portion 20a ahead of the shaft tube inner hole, and the convex portion 22b is in close contact with the inner hole surface in front thereof. The engaging portion 22c is engaged with the rear inner hole surface in a biting manner.
In addition, it is also possible to provide a groove part and a protrusion between the inner hole surface of the shaft tube 20 and the outer peripheral part of the receiving member 22 and to lock them using elastic deformation.

  As described above, the valve chamber 23 is formed between the receiving seat 21d serving as the rear end of the rib 21c and the valve body receiving seat 22a serving as the front end of the receiving seat member 22. A spherical valve body 24 is inserted before the receiving member 22 is locked, and the valve body 24 is loosely fitted in the valve chamber 23. The valve body is not limited to a spherical shape but may be a rod-shaped piece. In that case, it is not necessary to provide the rib 21c at the front end of the valve chamber by forming a groove for allowing ink to flow in the front outer periphery of the valve body.

  The tip 25 is crimped so that the tip ball 26 is rotatably held in a state where the tip ball 26 is substantially in contact with a seat having a channel through which ink can flow. In addition, a spring 27 is inserted into the tip inner hole 25a, the rear end of the shaft portion 25b behind the tip is appropriately crimped, and the rear end of the spring 27 is provided so as not to be extracted. Further, an upright rod shaft portion 27 a is formed at the tip of the spring 27, and the tip of the rod shaft portion 27 a abuts against the back surface of the tip ball 26 in a pressing manner. The tip ball 26 is brought into close contact with the inner edge of the ball holding portion of the chip 25 by the pressing. The tip 25 is pressure-bonded to the inner hole 21 a at the tip of the front shaft portion 21. In addition, it is possible to provide a pressing member for pressing the back surface of the tip ball 26 on the front surface of the spring, and it is also possible to form the rod shaft portion in a coil shape with a very thin winding. Furthermore, the tip can be made of a resin molded product with excellent wear resistance and ink sealing performance, and the spring seat that presses the back of the tip ball can be configured as an integral or separate spring seat. is there.

  As described above, when the tip side is faced downward, the valve body 24 comes into contact with the receiving seat 21d, and the tip ball 26 passes from the tip inner hole 25a through the groove formed between the guide hole 22d, the valve chamber 23, and the rib. Conducts up to the back.

  The shaft cylinder 20 has an ink containing portion behind the guide hole 22d. The ink containing portion is filled with low-viscosity ink or shear-thinning ink, mainly white pigment ink 28. The rear end is filled with a grease-like follower 29 that follows the ink as the ink is consumed. Further, the follower is not compatible with ink and has a performance of preventing ink evaporation. Further, if necessary, a resin-made follower rod 30 having a specific gravity substantially equal to that of the follower is immersed in the follower. The follower may be a follower such as silicon rubber.

  Further, the white pigment ink 28 contains at least a white pigment such as titanium oxide and polymer hollow fine particles and a gelling agent, and is mixed so that the precipitation of the pigment is prevented and the fluidity is not impaired as much as possible. It is. In addition, since the ink has shear thinning viscosity, it can be applied with high concealability in combination with a decrease in viscosity due to rotation of the tip ball.

A pumping type pressurizing mechanism is provided at the rear end of the shaft cylinder 20. The configuration of the pressurizing mechanism is basically the same as that of the first embodiment described above. In the case of this embodiment, the bush 31 is made of resin, and a cylindrical elastic body 32 having a slit 32b on the bottom surface 32a of the front end is fitted in front of the cylindrical portion, and the knock bar 33 advances. Thus, the convex portion 33d abuts on the step portion 31b of the bush 31 and further advances, whereby the front of the cylindrical body of the bush front 31 is expanded, the elastic body 32 is expanded, and the slit portion 32b is expanded. Open.
Moreover, although the valve mechanism part mentioned above has comprised the elastic body by fitting in the cylindrical body front of the bush which has rigidity, it is also possible to form the whole with an integral elastic body.

10 and 11 show a pumping type pressurizing mechanism of the ballpoint pen 41 according to the fourth embodiment. This pumping type pressurizing mechanism is composed of a valve mechanism part in which the inside of the ink containing tube is closed and a knock mechanism part provided so as to compress a space part formed behind the valve mechanism part. It is configured.
First, the valve mechanism is disposed at the rear end of a follower that is disposed so as to contact the rear end of the ink and follow the ink as it is consumed.
In the embodiment, the bush 44 is fixed at a predetermined position of the inner hole of the ink containing tube 42 by a cylindrical body having a bottom surface 44c whose front end is closed. Further, a vent hole 44a is provided at a required location on the peripheral surface of the cylindrical body, and the vent hole 44a is secured to the front surface of the ink containing tube without contacting the inner surface of the ink containing tube 42.

An elastic body 45 is tightly fitted in the inner hole of the bush 44. The elastic body 45 has fine continuous pores, a spherical convex portion 45b is formed at the front end, and a seal portion 45a that is in close contact with the inner surface 44b of the bush 44 and is in sliding contact is formed at the rear end peripheral surface. .
In the elastic body 45, the seal portion 45a normally seals the vent hole 44a, and the space between the rear end of the follower 43 is closed.

A knock mechanism is disposed behind the valve mechanism.
A tapered slit portion 42b that is tapered from the rear end side toward the front side is formed on the side surface of the rear end portion of the ink containing tube 42, and has a step portion 42c at the front end thereof to have a predetermined length in the axial direction forward. 42a is formed. Further, the knock bar 46 is formed with a flange portion at the rear end and a shaft portion at the front thereof, a step portion 46b is provided at the front end of the flange portion, and substantially between the protrusion 46a and the outer periphery of the shaft portion in the middle of the outer periphery of the shaft portion. A circumferential groove 46c is provided at the front end, and a seal ring 47 made of an elastic body such as rubber or an elastic molding resin is fixed to the groove 46c as an example. As the seal ring 47, one having good airtightness and slipperiness is selected. In addition, other lubricants are taken into consideration. Further, the seal ring portion can be integrally formed on the outer periphery of the shaft portion.

The knock bar 46 is inserted from the rear end of the ink containing tube 42, a knock spring 48 is laid between the step 46b and the rear end of the ink containing tube 42, and the protrusion 46a has the tapered shape. The slit portion 42b is elastically expanded, the protrusion 46a is locked to the front surface of the step portion 42c, and the knock bar 46 is always urged rearward by the knock spring 48 with respect to the ink containing tube 42. Further, the shaft portion front of the knock bar is fitted into the rear end hole of the ink containing tube 42, and the outer peripheral portion of the seal ring 47 is in sliding contact with the inner peripheral portion of the rear end hole. At that time, the seal ring 47 is located in a state immediately before the front end of the slit portion 42a. Therefore, the space 49 formed between the rear end of the elastic body 45 and the front end of the knock bar 46 is It communicates with the outside air. That is, immediately before the knock bar 46 is moved forward, the space 49 of the ink containing tube 42 is communicated with the outside air, and immediately after the knock rod 46 is properly advanced, the outer peripheral portion of the seal ring 47 is the inner peripheral portion of the ink containing tube 42. By being in close contact with the outside air, it is cut off from the outside air and pressurized with the reduction of the space 49. Further, in a state where the knock bar 46 is moved forward and the space 49 is appropriately compressed, the convex portion 46d provided at the front end of the knock bar 46 abuts on the rear end of the elastic body 45 and further moves forward to move the elastic body 45. The convex portion 45b is pressed and deformed, the seal portion 45a is advanced, and the vent hole 44a of the bush 44 is opened. (See Figure 11)
The deformed part shape and the seal part shape of the elastic body can be various forms depending on the design convenience, but in any case, the elastic body is deformed or displaced by the pressing of the convex portion provided at the front end of the knock bar, Seal and open the vents.

(Function)
First, FIG. 1 shows a knock-type writing instrument being carried. From this state, when the rear end of the knock cylinder 3 is pressed forward, the locking projection 3a pushes up the ball 1b of the clip 1a and moves forward to engage with the locking step 1c. The tip 7 protrudes from the tip hole 2 a of the front shaft 2. (See Figure 2)
In this state, the space 18 at the substantially rear end of the ink containing tube 10 communicates with the outside air through the slit portion 10a, and the setting forces of the return spring 4 and the knock spring 17 are so balanced. When carrying the knock-type writing instrument again, if the tip of the clip 1a is elastically displaced slightly upward or laterally to release the engagement between the locking step 1c and the locking projection 3a, the return spring 4 The ballpoint pen refill 5 is retracted, and the tip 7 is immersed inside the front shaft 2.

Next, the operation of the pumping type pressurizing mechanism will be described below.
If the rear end of the knock cylinder 3 is pushed forward from the state shown in FIG. 2, the front end 6 f of the joint 6 abuts against the step 2 b provided on the front shaft 2 to prevent the advance, and the ink containing tube 10. In contrast, the knock bar 15 starts moving forward. As shown in FIG. 5, when the outer peripheral portion of the seal ring 16 comes into close contact with the entire inner peripheral portion of the ink containing tube 10, the space 18 at the substantially rear end of the ink containing tube is blocked from the outside air, and the knock bar 15 As the ink further advances, the outer peripheral portion of the seal ring 16 slides in close contact with the inner peripheral portion of the ink containing tube, and the internal pressure increases as the space portion 18 shrinks. Further, in a state where the knock bar 15 is advanced and the space portion 18 is appropriately compressed, the convex portion 15d provided at the front end of the knock bar 15 contacts the step portion 13b formed in the inner hole of the bush 13, and further advances. By expanding the front of the cylindrical body against the elastic body 14 and opening the slit 13c of the bottom surface 13d, a vent is formed, and the compressed air is pushed forward. The trailing end of the follower 12 is pressurized to support the fluidity of the ink toward the tip side.

That is, it prevents the ink from separating from the peripheral surface of the tip ball due to a drop impact or poor ink fluidity and prevents the continuous outflow of ink and recovers when interrupted. Become.
Also, an appropriate pressure is set depending on the characteristics of the ink. In that case, the volume of the space 18 when the outer peripheral portion of the seal ring 16 is in close contact with the entire inner peripheral portion of the ink containing tube 10 and the convex portion 15 d provided at the front end of the knock bar 15 are the steps of the inner hole of the bush 13. It is set in consideration of the leak value of the seal part (in the seal ring part and the slit part), how much the volume of the space part 18 is in contact with the part 13b and the slit part 13c is opened. It becomes possible.
Further, since the elastic body is formed of a sponge-like material having fine continuous pores, the pressurized state leaks over time and becomes in equilibrium with the external pressure. Therefore, especially when the applied pressure exceeds a predetermined set value, it is possible to avoid the problem that the ink is not used and the ink is blown out due to inadvertent external force on the writing tip. Become. The material, shape, and porosity of the elastic body are set so that the time during which the pressurized state leaks and is in equilibrium with the external air pressure is in a state suitable for the form of use.
Also, in order to safely carry the ballpoint pen immediately after pressurization, the knock bar is fixed in the forward movement state, and the valve mechanism is opened so that the rear end of the follower is in equilibrium with the external air pressure. Is possible.

Next, the function of the ballpoint pen 5 will be described.
First, in a state where writing is not performed, the tip ball 8 is brought into close contact with the inner edge of the chip holding portion by the pressing of the spring 9, so that direct current and backflow of the ink 11 are prevented. Further, since the tip ball 8 is slightly retracted by the writing pressure, a gap is formed and the ink can flow out, and the ink is written by the rotation of the tip ball 8 by writing.
Even when the spring 9 is not pressed, if the ink viscosity is not too low, the ink filling amount is not too large, or the ink containing tube is not too thick, the rear end of the follower is pressurized. Ink can prevent direct current and backflow.
However, in consideration of writing with the tip 7 facing upward or repeated knock impact when mounted on a knock-type writing instrument, it is desirable to press with the spring 9 to prevent direct current and backflow of ink.

The follower bar is used when the ink containing tube has a large diameter.
That is, the grease-like follower has a problem that when the ink containing portion has a large diameter, the grease-like follower is easily deformed due to the influence of an impact or the like. It is possible to increase the rigidity by immersing a resin-made follower rod having a specific gravity substantially equal to that of the follower in the follower.

  In addition, the direct current and the backflow of the ink are effected by pressing the tip ball with the spring, but the tip ball is brought into close contact with the inner edge of the ball holding portion by the spring and a valve chamber in which a valve body is loosely fitted is provided behind the tip ball. Provided so that the valve body faces upward and the valve body closes the guide hole, the incomplete contact state with the tip ball due to processing variations of the ball holding portion, and the clearance between the ball holding portion and the tip ball Even if a solid incomplete state occurs when solid matter adheres to the ink, backflow of the ink can be reliably prevented.

The ink backflow prevention structure with the follower bar and valve body described above demonstrates the performance when the ink container has a large diameter and is easy to backflow, when repeated upward writing, or when an impact is applied. It is not essential as a component, and in particular, a ballpoint pen for correcting errors is rarely used because it is rarely used upward.
The operation of the above-described pressure-type ballpoint pen has been described according to the first embodiment. However, the operations of the second and third embodiments and the fourth embodiment are basically the same, and the description thereof is omitted.

BRIEF DESCRIPTION OF THE DRAWINGS It is the longitudinal cross-sectional view of a partial non-section which mounted the pressure type ball-point pen which is Example 1 of this invention in the knock-type writing instrument, and has shown the state where the writing tip was immersed. It is a longitudinal cross-sectional view of a partial non-section in a state where the writing tip is protruded by knocking. 1 is a longitudinal sectional view showing a first half of a pressure-type ballpoint pen that is Embodiment 1. FIG. 1 is a longitudinal sectional view showing a second half of a pressure ballpoint pen that is Embodiment 1. FIG. 1 is an enlarged cross-sectional view of a pumping type pressure mechanism of a pressure type ballpoint pen that is Embodiment 1. FIG. 6 is a longitudinal sectional view showing the first half of a pressure-type ballpoint pen that is Embodiment 2. FIG. FIG. 6 is a longitudinal sectional view showing the latter half of a pressure type ballpoint pen that is Embodiment 2. 6 is a longitudinal sectional view showing the first half of a pressure-type ballpoint pen that is Embodiment 3. FIG. FIG. 6 is a longitudinal sectional view showing the latter half of a pressure-type ballpoint pen that is Embodiment 3. FIG. 6 is a longitudinal sectional view showing the latter half of a pressure type ballpoint pen that is Embodiment 4. In the longitudinal cross-sectional view which showed the second half of the pressurization-type ball-point pen which is Example 4, the pumping state is shown.

Explanation of symbols

1 shaft cylinder 1a clip 1b ball 1c locking step 1d window hole 1e base 1f elastic piece 1g inclined surface 1h step 2 front shaft 2a tip hole 2b step 2c inner step 3 knock cylinder 3a locking projection 3b rib 3c Safety piece 4 Return spring 5 Ballpoint pen 6 Joint 6a Front shaft portion 6b Hook portion 6c Rear shaft portion 6d Tip fitting hole 6e Step portion 6f Front end 7 Tip 8 Tip ball 9 Spring 9a Bar shaft portion 10 Ink receiving tube 10a Slit portion 10b Taper Shaped slit portion 10c step portion 11 ink 12 follower 13 bush 13a inner hole 13b step portion 13c slit portion 13d bottom surface 14 spring body 15 knock bar 15a protrusion 15b step portion 15c groove portion 15d convex portion 16 seal ring 18 space spring 18 Part 19 Ballpoint pen 20 Shaft cylinder 20a Step part 2 0b Circumferential portion 20c Slit portion 20d Tapered slit portion 20e Step portion 21 Lead shaft portion 21a Inner hole 21b Hole portion 21c Rib 21d Front receiving seat 22 Receiving seat member 22a Valve body receiving seat 22b Protruding portion 22c Locking portion 22d Guide Hole 23 Valve chamber 24 Valve body 25 Tip 25a Tip inner hole 25b Shaft portion 25c Caulking portion 26 Tip ball 27 Spring 27a Rod shaft portion 28 Ink 29 Follower 30 Follower rod 31 Bush 31a Inner hole 31b Step portion 31c Slitting portion 32 Elastic body 32a Bottom 32b Slot 33 Knock bar 33a Projection 33b Step 33c Groove 33d Projection 34 Seal ring 35 Knock spring 36 Space 37 Ball pen 38 Front shaft 39 Shaft cylinder 40 Follower 41 Ball pen 42 Ink receiving tube 42a Slit 42 Te Super slit portion 42c Slit portion 43 Follower 44 Bush 44a Vent 44b Inner surface 44c Bottom surface 45 Elastic body 45a Sealing portion 45b Protruding portion 46 Knock bar 46a Protruding portion 46b Step portion 46c Groove portion 46d Protruding portion 47 Seal ring 48 Space spring 49 Part

Claims (3)

The tip of the ballpoint pen and the ink storage tube at the back are filled with ink and the ink follower is filled with ink and the ink follower at the rear end of the ink. In a pressure type ballpoint pen in which a pumping type pressure mechanism is provided in an inner hole of a cylindrical body provided so as to be integrated,
In the pumping type pressurizing mechanism, an elastic body having fine continuous pores is provided at a position facing the rear end of the follower, and the rear end of the follower is normally in a sealed state with the outside air. The valve mechanism part in which the rear end of the follower is connected to the outside air is formed by the deformation of the follower, and the valve mechanism part can be moved forward and backward while being always urged rearward by a knock spring. And a knock mechanism portion formed by compressing a space portion formed between the vent and the front end of the knock rod when being advanced, and the space portion is formed by advancing the knock rod. A pressure ballpoint pen, wherein the elastic body is configured to be deformed by receiving an external force from a knock bar in a properly compressed state.   The bottom of the elastic body is provided with a slit part that becomes a vent or a required number of micro holes that are normally closed, the slit part is normally sealed and the rear end of the follower is in a closed chamber, and a knock bar The front end is provided with a convex portion, and is configured such that the slit portion or the minute hole is expanded by an external force by the convex portion in a state where the knock bar is advanced and the space portion is appropriately compressed. Item 2. A pressurized ballpoint pen according to Item 1. The valve mechanism portion is provided with a cylindrical body having a vent hole that communicates only with the rear end side of the follower at a position facing the rear end of the follower, and an elastic body is provided so as to seal the vent hole. The vent is opened by deforming the elastic body by an external force generated by a convex portion provided at the front end of the knock bar in a state where the knock bar is advanced and the space is appropriately compressed. A pressure-type ballpoint pen described in 1.

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