JP3602282B2 - Ballpoint pen - Google Patents

Description

[0001]
[Industrial applications]
The present invention secures smooth writing performance by utilizing that the pressure of the spring held in the holder is weaker than the writing pressure required for writing when writing is performed, and the writing section is used when writing is not performed. Improvement of ball-point pens that use a ball as a valve to improve the impact resistance and the prevention of ink dry-up, eliminating the need for a tip seal and preventing ink drops from moving backward. .
[0002]
[Prior art]
In a general ballpoint pen, a gap around the ball, which is a writing portion, through which ink necessary for writing flows out is appropriately provided. Therefore, the ink evaporates from the gaps, vibrates during transportation, falls, ink oxidative deterioration due to long-term storage, ink leakage occurs due to leakage or air entry, and the writing section can be used for a long time with a pen stand at the store. When stored upward (hereinafter referred to as “upward”), accidents such as ink drops where ink drops axially rearward are often seen. Conventionally, in order to solve these problems, application proposals of the invention in which a spring is provided inside a tip which is seen with a writing instrument type correction fluid or the like (Japanese Utility Model Laid-Open Nos. 55-172104 and 57-193578). In addition to the springs, these require a metal cutting push rod that requires a significant increase in cost. It is very difficult to extend from the center of the spring without bending from the manufacturing method of the spring. In addition to requiring considerable quality control during manufacturing, the end face of the spring is still cut, The edge of the end face of the spring and burrs will be caught on the inner surface of the chip due to bending, and the trouble that the ball will not be pressed is likely to occur. Therefore, the secondary and tertiary additional processes such as straightening the tip straight to the center and rounding the edge of the tip are specifically performed, and have the problem that considerable cost and labor are required. ing. In addition, there is little difference in the direction of inserting with very small parts during assembly, and it is easy to cause problems in performance even if the direction is wrong or it gets caught very slightly, so the shape of the spring that is easy to insert into the chip, In order to prevent the spring from being bent in the assembling work, there is a demand that the spring be loosely fitted into the chip first. In addition, if the tip is made by cutting metal or made of resin, it is necessary to reduce the diameter of the core pin because it requires a draft, and the spring must be smaller than the minimum diameter. A part such as a joint for receiving the rear end of the spring on the inner surface connecting the chip and the chip and a spring receiver are required, which further increases the cost.
[0003]
[Problems to be solved by the invention]
Accordingly, the present invention provides a method for preventing dry-up due to volatilization of ink, preventing leakage of ink due to impact during dropping and transport, and preventing long-term upward storage at a store, without hindering smooth writing at the time of writing. Satisfies the desire to reliably improve the accident prevention performance of ballpoint pens, such as ink drop prevention performance due to air inflow, and solves the problem of providing a general and inexpensive ballpoint pen that is easier to manufacture than conventional technologies. It is intended to do so.
In the present invention, the spring for pressing the tip ball is extremely weak (about 2 to 20 g), and the performance is not exhibited if the spring portion and the straight portion have a burred portion with respect to the chip inner hole. Therefore, the inner bore of the chip has a shape with as little step as possible.Also, the straight part is inserted into the center hole of the holder without interference, and an acute angle taper or burr that does not generate a step so that a small pressing force acts on the tip ball. It is necessary to consider a receiving seat having a depth that does not reach the rear end of the center hole in order to prevent the influence of the above. In addition, it is necessary to prevent the rear end of the spring from being pulled out without being deformed by incorporating a spring in the inner hole of the chip. It is difficult to form a chip that satisfies the above conditions in terms of processing accuracy, and there is a problem of stabilization of quality and an increase in cost due to a decrease in productivity.
Another object of the present invention is to make it possible to easily confirm an accurate end state and the type of ink color.
[0004]
[Means for Solving the Problems]
The present invention is a so-called so-called chip in which a spring is built in so as to press the tip ball, and the ink reservoir tube has a high viscosity statically, and the viscosity is reduced by rotation of the tip ball during writing so that the ink flows out. In a ball-point pen in which a water-based ink or a low-viscosity oil-based ink having a shear-thinning viscosity and a grease-like follower that fills the rear end of the ink with the consumption of the ink, the tip is a writing tip at the tip. The rear end of the spring abuts the metal holder holding the ball, and the tip joint of a transparent resin molded product that makes it impossible to pull out is crimped. A straight portion is provided, and a coiled spring portion is further provided from the rear end of the straight portion toward the rear end.
[0005]
Also, as a first embodiment, in a ball joint in which a tip is fixed to the tip of a shaft joint provided at the front of the ink containing tube and the shaft joint, the tip end of the tip near the shaft center of the shaft joint is opposed. A valve chamber provided with a ball receiving seat and a guide hole at the rear end thereof for securing a flow path communicating from the ink storage tube to the tip ball of the writing portion is provided eccentrically with respect to the axis of the chip as appropriate, The ball valve is loosely fitted, the tip of the tip is downward, and the ball valve is biased to the rear end of the tip to abut, allowing ink to flow into the tip. The tip of the tip is upward, and the ball valve is in close contact with the ball receiving seat. Then, when the guide hole is closed, the backflow of the ink is prevented.
[0006]
Also, as a second embodiment, a piece protruding forward of the shaft is provided at a required location on the periphery of the valve chamber, and when the chip is crimped to the shaft joint, the rear end of the chip presses against the piece, Are curved to the axial center side to form a contact portion on the front side of the ball valve.
[0007]
Further, as a third embodiment, the rear end of the spring is inserted into the tip joint in an abutting state, and a straight portion that abuts on the tip ball of the spring is wound backward from the rear end of the straight portion. A bent end toward the center is further provided at the rear end of the winding portion, and a tapered or spherical ball receiving seat and a guide hole are provided at the tip joint inner hole behind the rear end of the spring. A ball valve is loosely fitted between the bent end portion and the ball receiving seat, and a guide hole is provided in communication with the rear end opening of the tip joint. Is provided with an ink storage tube behind.
[0008]
Also, as a fourth embodiment, a refill-type ball-point pen mounted in a barrel of a writing instrument, wherein the holder and the holder have a length such that the ink can be seen from the outside in an axial dimension protruding from a tip end opening of the tip barrel. The axial size of the tip joint is set.
[0009]
【Example】
The ball-point pen with a built-in spring of the present invention presses the tip ball, which is a writing portion, with a spring only very weakly, and during writing, the ball and the spring move rearward of the shaft to secure a flow path of ink necessary for writing. It is configured to be writable like a simple ballpoint pen. The tip is formed by press-fitting a metal holder holding the tip ball and a tip joint made of a transparent resin molded product that abuts the rear end of the spring so that it cannot be pulled out. A material that can suppress the evaporation of the ink is selected for the tip joint. Accordingly, the processing accuracy of the chip as described above is facilitated, and the spring is easily incorporated so as not to be pulled out, so that the quality is stabilized and the total cost of chip formation is reduced.
[0010]
Hereinafter, the illustrated embodiment will be described in detail. 1 and 2 show a ballpoint pen 1 according to a first embodiment of the present invention. First, as shown in the figure, a shaft having a press-fitting portion 7a fixed to the inner writing portion side of an ink storage tube 9 for storing the ink 10 inside a tube made of a polypropylene resin and a hole 7b to which the tip 2 is press-fitted and fixed. The joint 7 is provided with a ball receiving seat 7c having an ink guide hole 7e at substantially the center of the inside thereof, and a ball valve 8 loosely fitted into a valve chamber formed by the axial rear end of the chip 2 and the ball receiving seat 7c. In normal writing, the structure is such that the ink storage tube 9 communicates with the tip ball 4 serving as a writing portion. In the upward direction, the ball valve 8 comes into close contact with the ball receiving seat 7c of the shaft coupling 7 to prevent backflow of ink. The ballpoint pen has a structure described above, and the ballpoint pen is a so-called ballpoint pen refill which is usually used by being inserted into a barrel (not shown) serving as a writing shaft.
[0011]
In this ballpoint pen, the ink 10 has a statically high viscosity, and the viscosity of the ink is reduced by the rotation of the tip ball 4 during writing, so that the ink 10 has a so-called medium viscosity having a shear thinning viscosity in which the ink flows out smoothly. A grease-like follower 11 is filled with a water-based ink or a low-viscosity oil-based ink to prevent the volatilization and outflow of the ink by coming into contact with the rear end face of the ink, and a follower is provided in the follower to improve drop resistance. A resin follower rod 12 having substantially the same specific gravity is immersed.
[0012]
FIG. 2 is an enlarged view of the tip 2 which is the writing tip of the ballpoint pen and the inside thereof. The chip 2 is configured by pressing a metal holder 3 to the tip of a chip joint 5 which is a transparent resin molded product. The holder 3 includes a tapered portion 3c and a press-fit portion 3f toward the tip. The holder 3a is supported by the holding portion 3a (formed by caulking) to support the tip ball 4 as a writing portion. It is loosely fitted loosely by the receiving inner surface. A tip joint 5 is press-fitted to the press-fit portion 3f at the rear end of the holder 3, and the front end surface is in contact with the tip ball 4 inside, and a spring 6 is provided at the rear end surface by a step 5a at the rear end surface of the tip joint 5. The spring 6 is inserted into the tip joint 5 with its rear end 6 c having a diameter substantially equal to or slightly smaller than the inner diameter of the rear end of the tip joint 5.
[0013]
In addition, since the spring portion does not come into contact with the inner surface of the holder 3 to prevent the movement of the spring action from being hindered , the insertion through the center hole 3d, which is the minimum diameter of the holder 3, is facilitated to facilitate insertion and detection of the orientation during assembly. In order to extend the straight portion 6a for pressing the tip ball 4 from the center of the holder 3 as much as possible, the inner hole of the holder 3 is usually smaller than the inner hole of the rear end. Considering that it is necessary to make the diameter smaller than the end side or to make the whole outer diameter of the spring sufficiently small, the spring 6 is provided with a small diameter portion 6b having a smaller diameter than the rear end portion 6c at the center thereof. A portion between the rear end portion 6c and the small diameter portion 6b is a portion having the spring property of the spring 6, but the portion has a tapered shape or a stepped shape. Further, the straight portion 6a extends from the outer diameter of the small diameter portion 6b, bends appropriately, and extends substantially on the axis.
[0014]
Further, the holder 3 is provided with a receiving seat 3b having a required number of grooves of a depth not reaching the rear end of the center hole 3d at the outer periphery of the front end of the center hole 3d holding the tip ball 4, and from the rear end of the center hole 3d. A joint step portion of the enlarged inner hole and an inner hole joint portion (produced by processing of the inner hole) expanding on the step toward the rear end of the holder 3 are connected by a taper having a central angle of approximately 90 ° or less. Therefore, the problem that the front end surface of the straight portion 6a is caught on the inner surface of the holder when the spring 6 is inserted is prevented.
In addition, if the ball valve 8 enters the rear end face side of the tip joint 5 during writing and comes into close contact therewith, the flow path of the ink cannot be secured and writing cannot be performed. Therefore, in the embodiment, the ball receiving seat 7c of the joint 5 is used. Is eccentric, and even if the ball valve 8 moves forward, it comes into contact with only one side of the rear end face of the tip joint 5.
[0015]
FIG. 3 shows a ballpoint pen 20 according to a second embodiment of the present invention. Hereinafter, differences from the first embodiment will be mainly described. First, as shown in the drawing, the ballpoint pen in this embodiment has an inner hole 22 into which the tip 2 is press-fitted and fixed to the inner diameter writing portion side of the ink storage tube 9 for storing the ink 10 inside a tube made of polypropylene resin. A shaft joint 21 having a rear shaft portion 29 that is press-fitted and fixed to the ink storage tube 9 is provided. In addition, it is possible to form the shaft coupling and the ink storage tube integrally. The tip 2 has a holder 3 holding a tip ball 4 serving as a writing portion at the tip, and a tip joint 5 is crimped to the holder 3.
[0016]
A valve chamber 23 is provided at the axial center of the shaft joint 21 so as to face the rear end face of the chip 2, and a tapered or spherical ball receiving seat 25 and a guide hole 27 are provided at the rear end thereof. A ball valve 28 is loosely fitted, a guide hole 27 is provided in communication with the rear end opening of the shaft coupling 21, and a piece 24 protruding forward in the axis at a required location on the periphery of the valve chamber 23 is provided. When the tip 2 is pressed against the shaft joint 21, the rear end of the tip 2 is pressed against the piece 24, and the piece 24 is bent toward the axial center side to form a contact portion on the front side of the ball valve 28. It is configured as follows.
[0017]
4 and 5 show a ballpoint pen 30 according to a third embodiment of the present invention. Hereinafter, differences from the above embodiment will be mainly described. First, as shown in the drawing, the ball-point pen in this embodiment has a front shaft portion 36a in which a tip 31 is press-fitted and fixed to the inside writing portion side of an ink storage tube 9 for storing ink 10 inside a tube made of polypropylene resin. And a shaft joint 36 having a rear shaft portion 36c which is press-fitted and fixed to the ink storage tube 9. In addition, it is possible to form the shaft coupling and the ink storage tube integrally.
[0018]
The tip 31 is formed by holding a tip 32 holding a tip ball 4 serving as a writing portion at the tip, a tip joint 33 being crimped to the holder 32, and a rear end of a spring 34 being inserted into the tip joint in a contact state, At the tip of the spring 34, a straight portion 34a abutting on the tip ball 4 is provided, a winding portion 34b is provided rearward from the rear end of the straight portion, and a bent end portion 34c is provided at the rear end of the winding portion 34b toward the center. ing. Further, a tapered or spherical ball receiving seat 33c and a guide hole 33e are provided in the inner hole 33b of the tip joint 33 further behind the rear end of the spring 34, and between the bent end 34c and the ball receiving seat 33c. A ball valve 35 is loosely fitted in the shaft coupling 36, and a guide hole 33e is provided in communication with the rear end opening of the tip coupling 33. An ink storage tube 9 is provided behind 36 to form a ballpoint pen. A rib 33d is provided at a required position on the inner wall of the valve chamber 33f in front of the ball receiving seat 33c, and the rear end of the rib 33d serves as a contact portion of the rear end of the spring 34.
[0019]
6 and 7 show a fourth embodiment of the present invention. This embodiment is a refill-type ball-point pen in which the ball-point pens configured in the first to third embodiments are mounted in the barrel of the writing implement. The length of the holder and the tip joint in the axial direction is set so that the ink can be seen through. FIG. 6 shows a first example of use in which a tip portion of a tip is projected from a tip end of a base 14 screwed to a tip end of a shaft cylinder 13.
FIG. 7 shows a usage example 2 in which two types of ballpoint pens with refills 44 a and 44 b having different ink colors and the like are mounted in a shaft cylinder, and a rear end operating body 42 is rotated with respect to a rear shaft 41. In FIG. 5, the tip portions of the respective chips 45 are alternately protruded and retracted from the tip end of the front shaft 40 by interlocking the refills 44a and 44b of the ballpoint pen via the rotation mechanism 43. In addition, it can be used for various specifications such as knock type.
[0020]
[Action]
First, the operation of the first embodiment will be described. The tip ball 4 as a writing portion is spherical, and when the tip ball 4 is pressed from behind by a spring 6 by the holding portion 3a of the holder 3, the valve is in a closed state, and the outside air and the back surface of the tip ball are closed. By shutting off the side, it can be expected to prevent dry-up due to volatilization of the ink 10, prevent air from entering due to impact and drop, prevent leakage of the ink 10, and prevent ink deterioration on the back side of the tip ball due to air. become.
[0021]
The writing pressure required for writing at the time of writing varies depending on the type of ballpoint pen, but generally ranges from 50 g to 500 g. Since the set pressing force of the spring 6 for pressing the tip ball 4 of the present invention is set to 2 g to 100 g, preferably 5 g to 20 g, the valve mechanism by the tip ball 4 and the holding portion 3 a pushes and spreads during actual writing. In this state, the ink 10 flows out like a normal ball-point pen and writing is possible. In addition, when the writing is completed and the ballpoint pen is released from the paper, the valve of the writing part is instantly closed by the force of the spring and dry-up resistance, impact resistance, air entry resistance, ink leakage prevention again Performance is demonstrated.
[0022]
Also, the combination of the tip ball 4 which can prevent the direct current and the backflow of the ink and the shaft coupling 7 having the valve structure of the ball valve 8 improves the safety of the air entrainment and the backflow of the ink when writing upward. In particular, a so-called medium-viscosity ballpoint pen using a shear-thinning ink in which the ink easily moves exhibits an effective performance.
[0023]
In addition, since the straight portion 6a of the spring 6 is slightly bent from the outer diameter of the coil of the small-diameter portion 6b which is easily straightened during manufacture of the spring, and is provided on the axis, the bending hardly occurs during manufacture. Further, since the short holder 3 is press-bonded to the chip joint 5 to form the chip 2, the processing accuracy of the chip is increased and the quality is improved. Also, the productivity is good.
[0024]
Next, a second embodiment will be described. First, when the chip 2 is crimped to the shaft joint 21, the rear end of the chip joint 5 is pressed against the piece 24, and the piece 24 is bent toward the axial center, so that the ball valve 28 is securely contacted with the front side. Department. The ink is supplied to the tip ball 4 through the space between the pieces. By changing the width of the piece 24 and the required number of pieces, the required amount of ink flowing out can be set.
Therefore, as in the case of the conventional valve chamber, in which a required number of protrusions are provided in the valve chamber to prevent the ball valve from being removed, there is a concern that the protrusions may be damaged when the dimensional accuracy is obtained during molding or when the ball valve is inserted into the valve chamber. In addition, there is no problem that the ball bites into the ridge portion in the centrifugal treatment in order to remove bubbles trapped after the ink is filled during manufacturing, and the ball is fixed.
In addition, in comparison with the first embodiment in which the axis of the valve chamber is appropriately eccentric with respect to the axis of the chip fitting hole, it is necessary to increase the ink viscosity. It is effective for required specifications.
[0025]
Next, a third embodiment will be described. In this embodiment, a spring 34 for pressing the tip ball 4 and a valve chamber 33f for loosely fitting the ball valve 35 are integrally provided in the tip 31, so that a tip of a general oil-based ball-point pen that does not require a backflow prevention mechanism for ink is provided. It is possible to improve the productivity by making the outer dimensions the same and omitting the shaft joint, or sharing the shaft joint and the ink storage tube.
[0026]
A fourth embodiment will be described. By exposing the tip joint that allows the remaining amount of ink to be visible from the tip end of the barrel, it is possible to easily confirm the correct writing state and the type of ink color.
[0027]
【The invention's effect】
The configuration and operation of the ballpoint pen of the present invention are as described above, and writing is performed in a state in which writing performance is not affected at all by the spring built into the chip and the valve mechanism of the tip ball which is a writing portion. It can significantly improve ink dry-up prevention performance, drop impact resistance, ink drop resistance, and ink leakage resistance when not available, and the effect is expected from the moment the ballpoint pen is released from the paper after writing is completed You can do it. Therefore, it is possible to provide a ballpoint pen refill that can be mounted on a knock-type or double-type writing instrument that does not require a seal cap. In addition, by forming the chip with two parts of the holder and the chip joint, the processing accuracy and productivity of the chip are improved and the cost is reduced. In addition, since the transparent tip joint that allows the remaining amount of ink to be visible is exposed from the tip end of the barrel, it is possible to easily confirm the accurate writing state and the type of ink color.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing the entirety of a ballpoint pen which is Embodiment 1 of the present invention.
FIG. 2 is an enlarged cross-sectional view of the chip according to the first embodiment.
FIG. 3 is a longitudinal sectional view showing the entire ballpoint pen which is Embodiment 2 of the present invention.
FIG. 4 is a longitudinal sectional view showing the entire ballpoint pen which is Embodiment 3 of the present invention.
FIG. 5 is an enlarged sectional view of a chip according to a third embodiment.
FIG. 6 is a cross-sectional view illustrating a main part of Example 4 of using the ballpoint pen of the present invention in Example 4 of the present invention.
FIG. 7 is a longitudinal sectional view of a dual-purpose writing instrument according to a fourth embodiment of the present invention, showing a second application example of the ballpoint pen of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ball-point pen 2 Tip 3 Holder 3a Holder 3b Receiving seat 3c Tapered portion 3d Center hole 3e Forward portion 3f Press-fit portion 4 Tip ball 5 Tip joint 5a Step 6 Spring 6a Straight portion 6b Small diameter portion 6c Rear end 7 Shaft joint 7a Press-fit portion 7b Hole 7c Ball receiving seat 7d Groove 7e Guide hole 8 Ball valve 9 Ink storage tube 10 Ink 11 Follower 12 Follower rod 13 Shaft tube 14 Base 20 Ball pen 21 Shaft joint 22 Inner hole 23 Valve chamber 24 One part 25 Ball receiving seat 26 Rear end 27 Guide hole 28 Ball valve 29 Rear shaft 30 Ball pen 31 Tip 32 Holder 32a Forward 32b Press-fit portion 33 Chip joint 33a Shaft 33b Inner hole 33c Ball receiving seat 33d Rib 33e Guide hole 33f Valve chamber 34 Spring 34a Straight part 34b Winding part 34c Bending end 35 Valve 36 Shaft joint 36a Front shaft portion 36b Flange portion 36c Rear shaft portion 40 Front shaft 41 Rear shaft 42 Operating body 43 Rotating mechanism 44a Refill of ballpoint pen 44b Refill of ballpoint pen 45 Tip 46 Tip ball 47 Tip joint 48 Shaft joint 49 Ink Containment tube

Claims (6)

A chip with a built-in spring to press the tip ball, and a so-called shear thinning viscosity, in which the ink is statically high in viscosity and the ink drops when the tip ball rotates during writing, causing ink to flow out. In a ball-point pen with a water-based ink or a low-viscosity oil-based ink and a grease-like follower that fills the back end of the ink with the consumption of the ink, the tip holds a tip ball that serves as a writing part at the tip. The rear end of the spring abuts against the metal holder, and the tip joint of a transparent resin molded product that makes it impossible to pull out is crimped, and the spring has a straight part that abuts the tip ball at the tip of the writing part side A ball-point pen, wherein a coil-shaped spring portion is provided further toward the rear end than the rear end of the straight portion. The tip end of the spring is inserted into the tip joint with the rear end of the spring being in contact with the tip end of the spring. A bent end toward the center is provided at the rear end of the ball joint, and a tapered or spherical ball receiving seat and a guide hole are provided behind the rear end of the spring in the bore of the tip joint. A ball valve is loosely fitted between the seats, and a guide hole is provided so as to communicate with the rear end opening of the tip joint. The tip is fixed to the tip of the shaft joint, and an ink storage tube is provided behind the shaft joint. The ballpoint pen according to claim 1, wherein the ballpoint pen is provided. In a ball-point pen provided with a tip at the tip of a shaft joint provided at a front end of the ink storage tube, a ball receiving seat facing the rear end surface of the chip near the axis of the shaft joint, and a ball receiving portion. A valve chamber provided with a guide hole communicating with the ink storage tube is provided at the rear of the seat. A ball valve is loosely fitted in the valve chamber, and the tip of the chip faces upward so that the ball valve comes into close contact with the ball receiving seat. Backflow of ink is prevented when the guide hole is closed, and when writing with the tip end downward, the ball valve abuts the rear end of the tip, ensuring a path for ink to flow into the tip and allowing writing. 2. The ballpoint pen according to claim 1, further comprising a backflow prevention mechanism. A valve chamber is provided eccentrically with respect to the axis of the chip, the tip of the chip is directed downward, and the ball valve is biased against the rear end of the chip to form a flow path through which ink can flow into the chip. The ballpoint pen according to claim 3, wherein the ballpoint pen is formed as described above. In a ball-point pen provided with a tip at the tip of a shaft joint provided at a front end of the ink storage tube, a ball receiving seat facing the rear end surface of the chip near the axis of the shaft joint, and a ball receiving portion. A valve chamber having a guide hole communicating with the ink storage pipe is provided at the rear of the seat, and a piece protruding forward in the axial direction is provided at a required position on the circumference of the valve chamber. is fitted, the chip is pressed against the rear end of the chip at one portion when it is crimped to the shaft joint, piece portion is configured so that the front side of the abutment portion of the curved axis side ball valve The ballpoint pen according to claim 1, wherein: A refill-type ball-point pen mounted in a barrel of a writing instrument, wherein the axial dimension of the holder and the tip joint is such that the ink can be seen through from the outside in the axial dimension protruding from the tip end of the tip barrel. The ballpoint pen according to any one of claims 1 to 5, wherein the ballpoint pen is set.

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