JP3758802B2 - Knock-type writing instrument - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of a knock-type writing instrument that allows a writing tip portion to protrude and retract from a tip end of a shaft tube by knocking a knocking portion that protrudes to the rear end of the shaft tube, and is particularly filled with low-viscosity ink and writing This is an improvement related to a knock-type writing instrument in which a refill of a ballpoint pen that can be used without sealing the tip is mounted on a shaft cylinder.
[0002]
[Prior art]
Conventional oil-based ballpoint pens have a high viscosity of several thousand mPa · S or higher, and the resistance when the ball rotates when ink flows out of the pen tip is high. However, there is a problem that the amount of ink flowing out from the tip during writing is small, there is a blurring phenomenon, the writing line is uneven, the handwriting density is low, and a high writing pressure is required. On the other hand, there are writing tools such as ballpoint pens, sign pens, and markers that allow low-viscosity water-based inks of 10 mPa · S or less to be soaked into the fiber bundle core such as batting and the internal pressure to be adjusted by the ink retainer used in fountain pens As is known, these extremely low-viscosity writing instruments are vulnerable to impacts, it is difficult to check the remaining amount of ink, the ink volatilizes and faints at the nib, and ink leaks from the nib. For this reason, it is very difficult to provide a knock-type writing instrument that does not require a cap and has excellent operational feeling and portability.
As an improvement, recently, a ballpoint pen for water-based ink called medium viscosity using an ink having an intermediate viscosity region (several mPa · S to several thousand mPa · S) between the above water and oil has been developed. This is a ballpoint pen using a relatively low-viscosity aqueous ink having a characteristic that the viscosity is lowered by rotation of the tip ball and the ink flows out smoothly, so-called shear thinning. However, this has drawbacks such as that the ink is liable to dry, the ink is easily displaced by impact, and air enters the pen tip, and therefore a cap that normally seals the writing tip is required. Further, the amount of ink flowing out increases, and in order to extend the writing life, it is necessary to increase the ink filling amount by increasing the diameter of the ink containing tube.
[0003]
As an improvement of the above oil-based ballpoint pen, a ballpoint pen using a low-viscosity oil-based ink excellent in drying resistance is conceivable. However, the ink outflow amount increases, and the diameter of the ink containing tube is increased in order to extend the writing life. It is necessary to increase the ink filling amount by increasing the thickness. In addition, due to the low viscosity of the ink, when the tip side is faced downward, if a gap between the tip ball and the tip holding portion is generated, the ink may ooze out (direct current) or be less volatile than water. Oil-based inks, mainly composed of higher alcohol solvents such as propylene glycol, tend to get wet with the pen tip, and the ink dries at the tip of the pen immediately after writing, increasing the viscosity and preventing direct current. There are drawbacks, such as more problems.
[0004]
The above-mentioned medium-low viscosity inks such as medium-viscosity water-based inks and low-viscosity oil-based inks all have a relatively low-viscosity medium viscosity of about 10 to 5,000 mPa · S, and therefore the ink is liable to reverse flow and direct current. There is. If ink causes reverse flow or direct current, there is a risk of soiling clothes and the like, and there is a drawback that writing wrecking is likely to occur due to dropping or knocking impact. In addition, a medium-viscosity water-based ballpoint pen is usually filled with a grease-like non-drying substance called a follower at the rear end of the ink containing tube for the purpose of preventing volatilization and backflow. That is, reduction in evaporation from the gap between the ball and the holder may be considered. For example, a solvent with a very low vapor pressure, such as an oil-based ballpoint pen, is mainly used, a water-based hardly soluble solvent is blended with water, a thickener that does not thicken even if it is slightly volatilized, If the ink is coated with a film to make the inside less liable to volatilize, ink evaporation will not be considered much.
[0005]
The conventional knock-type ballpoint pen has a structure where the writing body is projected from the tip of the shaft and writing is performed, so if you forget to store the writing body when storing it in the pocket, the writing part will remain protruding out of the shaft. , Clothes were sometimes stained with ink. In particular, when the viscosity of the ink is 5000 mPa · s or less, there arises a problem that the ink penetrates into the clothing fibers just by contacting the clothing. In order to solve this problem, a device has been proposed in which a writing body is always stored when a writing instrument is inserted into a pocket by engaging the clip with a locking portion of a clip or a locking portion provided inside the shaft. In order to store the cursive body after pushing the knock rod at the rear end of the shaft and projecting the writing part of the cursive body from the front end of the shaft, these mechanisms are released by pressing the rear end side of the clip. However, in this case, the operability is different between the case where the cursive body is protruded and the case where the cursive body is stowed. When the cursive body is installed, the impact on the cursive body at the time of release may cause the ink inside the cursive body to shift or leak, or the air may be drawn from the tip of the cursive body and cause curling. Therefore, there is a drawback that a mechanism for buffering the impact on the cursive body is necessary.
Knock-type writing instruments that prevent the clothes from being soiled due to forgetting storage when storing pockets in the past, especially with medium-viscosity type writing instruments that have a large ink flow rate and become thick to ensure a long life, it is difficult to narrow the shaft, Only a thing with a thick appearance could be created.
Further, the refill is always urged rearward by a return spring, and if the rotor does not rotate smoothly while receiving the urging force, the operation is not completed to a desired state, and problems are likely to occur.
Furthermore, in the refill that needs to store the ink and the high-viscosity follower directly at the rear end, such as a medium-viscosity ballpoint pen, to remove the bubbles inside, the rear end that becomes an air hole at the time of manufacture is used. Ink is often filled with ink and followers.When defoaming, followers and ink move from the rear to the front of the air holes, and the internal bubbles need to move smoothly to the air holes and be released to the outside air. However, when the air hole at the back of the ink containing tube is smaller than the minimum inner diameter, there may be a drawback that the follower movement failure or defoaming failure occurs at the time of defoaming. The vicinity of the rear end of the refill is inevitably soiled with a grease-like follower, and it is difficult to wipe off the follower mainly composed of mineral oil or silicone oil, and this rear end is in direct contact with clothes. So when the clothes become dirty problem is also present.
[0006]
[Problems to be solved by the invention]
The object of the present invention is that even if medium-low viscosity ink is filled, the ink does not flow backward, the direct current phenomenon does not occur, the drying resistance of the writing tip is maintained and the cap can be removed and left alone, It is possible to provide a refill that can be mounted on a knock-type writing instrument by providing a mechanism for preventing ink backflow and ink direct current caused by upward writing. In addition, the mechanism that the writing tip protrudes and retracts is reliable and has good operability, prevents accidents that contaminate clothes when stored in the pocket, and reduces the number of parts and costs. In response to the desire to reduce the knocking impact on the cursive body, it is possible to make the appearance thinner and to provide a thin writing instrument for notebooks, etc. The object is to solve the problem of defoaming at the time of manufacture, and to provide a knock-type writing instrument with stable performance while ensuring smooth operation.
[0007]
[Means for Solving the Problems]
The present invention has the following configuration in order to achieve the above-described problems.
In other words, the knock type writing instrument according to the first aspect of the present invention is provided with a rotating cam mechanism portion that is locked at a forward retracted position with respect to the shaft tube by a knocking operation behind the shaft tube, and the rotating cam mechanism portion. A refill urged rearward by a return spring is provided in front of the head, and the operation of ejecting and storing the pen tip is repeated by pressing the knock bar. Furthermore, a clip projecting outward from the shaft cylinder is provided on one side of the rear of the shaft cylinder, and a locking surface is provided at the ball part at the tip, and a window or slit-like groove in which the ball part can be inserted from the outside of the shaft cylinder to the inside. It is drilled at a location facing the clip ball on the side surface of the shaft cylinder. The rotary cam mechanism has two axial positions where it comes into contact with a knock bar that moves back and forth by a knock operation, a cam slope provided on the knock bar, and a cam slope provided on the inner surface of the shaft tube or a part fixed to the shaft tube. Further, the cam slope is formed on the rotor, and the rotor is further provided with a projecting locking portion in front of the cam slope. It is formed on the ball part of the clip with springiness so that the rotor rotates by a constant rotation by the pressing action between the cam slopes by the advancement of the knock bar accompanying the knock operation, and is always pinched inward in the axial direction. The engaging surface and the engaging portion provided on the rotor are engaged or disengaged, and the writing front end portion of the refill is engaged with the shaft tube so that it can be projected and retracted. When the clip is displaced in a direction away from the side surface of the shaft cylinder as in the case of storing in the pocket with the writing portion protruding from the tip, the engagement is released and the writing tip is It is configured to be automatically immersible from the front end. Furthermore, by positioning the rear end of the refill and the engaging portion of the clip ball portion at the rear end of the refill in the axial direction, the engaging protrusion provided on the rotor is the diameter of the refill. It is possible to reduce the shaft diameter without overlapping in the direction, and the clothes do not come into direct contact with the refill.
[0008]
The knock type writing instrument according to a second aspect of the present invention is the knock type writing instrument according to the first aspect, wherein the refill incorporated in the shaft cylinder is used as the refill of the ballpoint pen, and the tip of the tip portion has a back surface of the tip ball. A ball receiving seat that abuts when writing pressure is applied thereto, and an ink inflow groove that allows ink to be supplied from the rear end of the chip to the tip ball near the ball receiving seat. The tip ball is always pressed and intimately contacted with the inner edge of the ball holding portion at the tip of the tip, and the tip provided so that the close state is released at the time of writing, and the ink behind the joint portion that fixed the tip to the tip The storage section is filled with medium to low viscosity ink with a medium to low viscosity of 10 to 5000 mPa · S at normal temperature, and the volume reduction of the ink that has flowed outside during writing is near the rear end of the ink storage tube. The air holes for allowing the air to flow into the inside are provided with a projected cross-sectional area approximately equal to or larger than the inner diameter of the ink containing tube. When the ink storage tube is formed by extrusion molding, it is not necessary to insert a part such as a tail plug in the same size. The refill used here desirably has a so-called shear thinning property that the ink viscosity decreases under high shear when writing and becomes relatively high under no shear or low shear as in non-writing. It is better to use a refill of a ballpoint pen with a non-volatile, grease-like follower that moves following the ink consumption accompanying writing at the trailing edge of the ink, or a pen tip inside the joint. It is more effective to use a knock-type writing instrument with a refill that includes a backflow prevention mechanism that secures the ink flow path when writing down, such as when the internal check ball closes the valve part to prevent backflow when writing upward. is there.
[0009]
The knock type writing instrument according to a third aspect of the present invention is the knock type writing instrument according to the first or second aspect, wherein air receiving means such as holes, grooves, and protrusions are provided on the receiving surface of the rotor. By eliminating clogging of the air hole at the rear end of the refill, the rear end of the ink containing tube has a chamfer on at least one of the inner diameter and the outer diameter, so that not only the movement in the front-rear direction but also the rotation can be achieved. On the other hand, as an auxiliary structure of the present invention that requires smooth operation, the contact resistance between the ink containing tube and the rotor is reduced.
[0010]
【Example】
FIGS. 1 to 3 show an example of an embodiment of the knock type writing instrument of the present invention. FIG. 1 shows a state where the refill is stored when not writing, and FIG. 2 shows a state where the pen tip protrudes. FIG. 3 is an enlarged view of the rear end portion of the pen tip protruding state.
4 and 5 show an example of the embodiment of the refill of the ballpoint pen mounted on the knock type writing instrument of the present invention. The ink 17 applied to the refill 1 of the ballpoint pen is a medium to low viscosity ink such as a water-based or low-viscosity oil-based ink having a medium viscosity of 10 to 5000 mPa · s at room temperature, and preferably shearing. It has a property of reducing viscosity.
FIG. 6 shows the outline of the operation of the cam mechanism of the present invention.
[0011]
As shown in the figure, the tip 12 is rotatably held by the tip ball 13 in a state where the tip ball 13 is substantially in contact with the ball receiving seat 14a having the channel portion 14 into which ink can flow and the crimping portion 14b. It is crimped inward. The channel portion 14 will be described in detail. The tip 12 is placed so that the tip 12 is in close contact with the inner edge of the caulking portion 14b when the tip 12 is in contact with the tip 12 when the writing pressure is applied. The elastic body 5 that presses the back surface is disposed inside the chip 12 without obstructing the ink flow path.
[0012]
It is very important for the tip ball 13 to be in close contact with the inner surface of the crimped portion 14b for drying the writing tip and preventing direct current of ink. When the tip 12 of the embodiment is made of metal, the inner surface of the tip 12 is substantially the same as the tip ball 13 in order to improve the surface roughness of the tip inner surface holding the tip ball 13 and the contact accuracy by caulking. It is more effective if it has the surface.
[0013]
The joint 2 is crimped to the tip of the shaft 12 at the tip, and is crimped to the front end of the ink containing tube 16 at the rear end. Further, a valve chamber 7 in which a check ball 15 is loosely fitted is provided behind the inner hole portion 10 of the joint 2, and a tapered or hemispherical check ball receiving seat 8 is provided behind the valve chamber 7. A guide hole 9 that is appropriately decentered with respect to the shaft center is provided, and the inner hole portion 10 communicates with the inner hole of the ink containing tube 16. A groove 11 is provided on one side of the inner wall of the valve chamber 7 so that the ink 17 flows in the axial direction. The check ball 15 loosely fitted in the valve chamber 7 forms an ink flow path in contact with a state biased to the rear end of the tip 12 when the tip 12 is faced downward. The ink 17 passes through the guide hole 9 and flows into the chip through the groove and the ink flow path. On the contrary, in the upward state, the check ball 15 is brought into close contact with the check ball receiving seat 8 and a function of preventing the back flow of ink can be obtained.
[0014]
The ink storage tube 16 is filled with the ink 17 of the above ballpoint pen, and further, from the grease-like translucent hard-to-dry material which can move following the ink 17 in contact with the ink surface as the ink is consumed. The follower 18 is filled. Further, a resin-made follower bar 19 having a specific gravity substantially equal to that of the follow is immersed in the follower 18 as necessary in order to prevent deformation due to dropping, knocking impact or the like. In addition, it is desirable to select a material excellent in the clear drain property (the ink or follower adheres when ink is consumed) for the ink containing tube 16. As an example, a transparent PP resin molded product or the like is used, and the remaining amount of ink can be confirmed. The ink storage tube can be formed integrally with the joint 2.
[0015]
The tip of the writing part of the refill 1 of the ballpoint pen is attached with a hot-melt type tip sealing material 25 that melts at 80 ° C. to 150 ° C. to suppress the volatilization of the ink. Get better. Thereby, it is possible to avoid troubles from the production until the writing is started.
[0016]
The shaft mechanism will be described in detail. First, the shaft cylinder includes a front shaft portion 3 and a rear shaft portion 4. In this knock type writing instrument, the refill 1 of the ballpoint pen is urged rearward by a return spring 24, and this force is transmitted to the rotor 22 and the knock bar 23, and finally the locking piece 21 c provided on the clip 21. is recieving. The clip 21 is fixed to the rear shaft portion 4 by a locking projection formed at the rear end of the locking piece 21 c provided inside the shaft tube being locked to a locking window provided in the rear shaft portion 4. .
[0017]
FIG. 6 is a front view showing a part of a developed view of the rear shaft part 4, the clip 21, the rotor 22, and the knock bar 23 and the position of the rotor 22 at that time, and shows the flow of the rotating cam mechanism part. In the order of A, B, C, and D, the state returns to the state A again, and during this time, the writing part appears and disappears once. Based on this, the rotating cam mechanism will be described. A rotor 22 is provided between the knock bar 23 and the refill 1 of the ballpoint pen. When the knock bar 23 is pressed, a cam slope 23a of the knock bar 23 and a cam slope 22c of the rotor 22 corresponding thereto are provided. A force applied in the axial direction is converted into a circumferential rotational force. At this time, the knock bar 23 is provided with a rotation stopper 23b, and the clip 21 is provided with a groove corresponding to the rotation stopper 23b. Therefore, the knock bar 23 does not rotate in the circumferential direction, and the rotor Only 22 is configured to rotate by a predetermined angle in the circumferential direction.
[0018]
At the initial stage of the knocking operation, the rotation restriction is exerted on the side surface of the cam 22a of the rotor 22 and the cam side surface of the rear shaft portion 4, and the rotor 22 does not rotate, but this rotation restriction is released when a constant distance knocking operation is performed. The rotor 22 rotates by a predetermined angle (FIG. 6B). At this time, the rotor 22 is always urged rearward by the return spring 24 through the refill 1 of the ballpoint pen, and when the pressing to the knock bar 23 is stopped, the cam inclined surface 22a of the rotor 22 and the corresponding rear shaft portion. 4, the rotor 22 is further rotated by a predetermined angle by the cam inclined surface 20 a, and the projecting locking portion 22 b of the rotor 22 is engaged with the locking surface 21 b formed on the ball portion 22 a of the clip 21 when the rotor 22 rotates by a predetermined angle. Thus, the writing tip portion protrudes from the front shaft portion 3.
[0019]
Here, when the state from B to C in FIG. 6 is described in detail, the cam inclined surface 22a of the rotor 22 moves back along the cam inclined surface 20a of the rear shaft portion 4, and at the same time, the engaging portion of the rotor 22 is moved. 22b also moves while drawing the same locus. At this time, in order for the locking portion 22b of the rotor 22 to engage with the locking surface 21b of the clip ball portion, it interferes with the lower end surface of the clip ball portion 21a. You must be able to pass without For this purpose, the distance R by which the cam inclined surface 22a of the rotor 22 moves may be set large, or the inclination angle θ of the cam inclined surface 20a of the rear shaft portion 4 may be made more obtuse. Since it becomes larger, the operability becomes worse, and in the latter method, the cam inclined surface 22a of the rotor 22 may stop on the cam inclined surface 20a of the rear shaft portion 4, so that the reliability of the operation is lacking. Here, as an example, it is desirable that the inclination angle θ be between 45 ° and 65 °. Furthermore, in order to solve this problem, it is only necessary to set the height so that the engaging portion 22b of the rotor 22 can pass through the lower end surface of the side wall surface of the clip ball portion 21a without interference. However, if the lower end surface of the other side wall surface is set to the same height as the lower end surface of the opposite side wall surface, the certainty of engagement is lost. It is desirable to increase the difference within a range that does not interfere with the diameter. In addition, the end surface of the locking surface 21b of the clip ball portion is a slope or curved surface that smoothly connects the lower end surface of the side wall surface and the lower end surface of the other side wall surface, so that when the clip is inserted into and removed from the clothes, it will not be caught. Can be done smoothly.
[0020]
When the knock bar 23 is pressed from a state in which the writing part protrudes from the front shaft part 3, the cam slant 23 a of the front end of the knock bar 23 and the cam slant 22 c of the rotor 22 are brought into contact with each other, and the locking surface 21 b of the clip ball part rotates. The engagement of the child 22 with the locking portion 22b is released. When the pressure on the knock bar 23 is stopped, the cam inclined surface 22a of the rotor 22 is retracted while rotating along the cam inclined surface 20a of the rear shaft 20, and the writing front end portion is stored in the front end opening of the front shaft portion 3. . At this time, the rotor 22 is set at the same position as in the initial state. That is, when the knock bar 23 is pressed again, the protruding operation is possible. Furthermore, the protruding state is released by engaging the engaging portion 22b of the rotor 22 and the engaging surface 21b of the clip ball portion by lifting the ball portion of the clip 21a upward without pressing the knock bar 23. The writing tip is stored in the tip opening of the front shaft portion 3 in the same manner as when the knock rod 23 is pressed. For this reason, if it tries to insert into a pocket with the writing front-end | tip part protruding, it becomes possible to prevent accidents, such as a writing front-end | tip part being automatically accommodated and soiling clothes.
The shape, angle, and number of cams can be selected as appropriate for the knock bar, the rotor, and the cam slope formed on the inner surface of the rear shaft necessary for these operations.
[0021]
In the present invention, the rear end of the refill 1 is arranged on the front end side in the axial direction of the engaging portion 22b of the rotor 22 so that the air hole 6 can communicate with the air hole 6 of the refill 1 of the rotor 22. In addition, the size of the air hole 6 of the ink containing tube 16 is set to be equal to or larger than the minimum inner diameter of the ink containing tube 16. As a specific example, the inner and outer diameters of the ink containing tube 16 are formed into substantially the same pipe shape by extrusion molding, and when the parts such as the joint 2 are fixed, the ink containing tube 16 is press-fitted and fixed only in the direction of expanding the inner diameter of the ink containing tube 16. It is. When a tail plug (not shown) or the like is fixed to the rear end of the ink containing tube, it is desirable that the inner diameter of the air hole where the follower 18 may come into contact is larger than the minimum diameter of the ink containing tube. This eliminates the problem that the follower dirt near the rear end of the refill 1 adheres to the clothes without increasing the shaft diameter. Furthermore, by adding chamfering to at least one of the inner and outer diameters of the portion that contacts the rotor 22 such as the rear end (or rear end of the tail plug) of the ink containing tube, the contact portion at the rear end is rotated by a burr or an edge. A stable operation can be ensured without biting into the child 22 and hindering the rotation of the rotor 22 by the cam mechanism. When the lubricant such as silicon oil or mineral oil, grease with viscosity, solid lubricant such as molybdenum disulfide or Teflon powder is applied to the cam part, the operation of the writing instrument of the present invention is further stabilized. Become a thing.
The refill of the most effective medium-viscosity ballpoint pen has been described in detail. However, as a writing instrument of the present invention, a sign pen, a fountain pen, a marker, and a crayon-shaped half, which is a general writing instrument that stains clothes if the pen tip is left out, is used. Anything that has a measure to prevent pen tip volatilization, such as a solid writing instrument, can be used.
[0022]
[Action]
First, an embodiment of a ballpoint pen refill will be described.
The refill 1 of the ballpoint pen prevents the direct current of the ink because the tip ball 13 is brought into close contact with the inner edge of the crimped portion 14b of the chip by the pressing of the elastic body 5. Further, since the tip ball 13 is slightly retracted by the writing pressure, a gap is formed and the ink 17 can flow out. By writing, the ink 17 is smoothly flowed out by the rotation of the tip ball 13 and there is no blur and writing with high handwriting density. Is possible.
[0023]
With the tip 12 facing upward, the check ball 15 is positioned on the ball valve seat 8 of the valve chamber 7 and seals the guide hole 9, so that the ink on the back of the tip ball 13 of the tip is written. Even if there is no ink, the head will hang on the ink and it will not flow backward. Accordingly, when the chip 12 is turned downward, the ink can immediately flow out, and dripping is prevented by writing. (By the way, in the structure that does not have a check ball, the ink works in the reverse flow direction with upward writing, so air is entrained in the tip, and the ink does not follow immediately with downward writing, and the ink is swollen)
[0024]
In the writing state with the tip 12 facing downward, the check ball 15 abuts against one of the rear ends of the tip 12 and a flow path through which ink can flow into the tip 12 is formed on the other side. The ink 17 that has entered the valve chamber 7 from the ink containing tube 16 through the guide hole 9 is guided to the back surface of the tip ball 13.
By the way, the action of the elastic body 5 can usually prevent direct current and backflow of ink, but air is caught by impact or upward writing, or the tip ball and the ball holding part are incompletely intimate (processing variation and dust In the case of entrainment or the like), there is a problem that writing wrinkles or ink backflow occurs. Therefore, the problem can be surely solved by using the check ball 15 for sealing the guide hole 9 together.
[0025]
On the other hand, in the knock type ballpoint pen that allows the writing tip portion of the refill 1 of the ballpoint pen to protrude from the tip end of the front shaft by pressing the knocking rod 23 protruding rearward of the rear shaft 4, the clip 21 Since the locking state 21b of the clip ball provided on the engaging surface 22b and the locking portion 22b of the rotor 22 can be engaged to maintain the protruding state of the tip of the writing, the engagement of the clip 21a is lifted. The writing tip portion is released and stored in the tip opening of the front shaft portion 3. Therefore, even if the writing tip part protrudes from the tip end of the front shaft and is inserted into the pocket, the writing tip is automatically housed in the tip end of the front shaft and prevents accidents in which clothes are stained with ink. be able to. By simply pressing the knock bar 23, the writing part can be protruded and stored, and the impact when the writing part is stored can be considerably relaxed by the finger in contact with the knock bar. It became possible to mount a refill of a ballpoint pen filled with the low-viscosity ink. Further, since the locking portion 22b of the rotor does not protrude outside the rear shaft 4 and the clip ball portion 21a does not have a protruding corner portion, it can be smoothly inserted into and removed from a pocket or the like. In addition to shortening the stroke, it is possible to improve the certainty of operation and improve operability.
Furthermore, it is possible to improve the appearance by making the shaft diameter thinner, and the grease-like follower will inevitably adhere to the rear end side of the outer diameter of the refill, resulting in opening a window on the shaft and clothes inside the shaft. It is possible to make up for the drawbacks of the above-described configuration that goes directly into the door and stains clothes with a follower.
After adopting a means for ensuring air replacement in the vicinity of the contact portion of the rotor 22 with the refill 1, chamfering is applied to at least one of the inner diameter and outer diameter of the rear end of the refill, thereby rotating the rotor 22 of the present invention. This makes it possible to smoothly move and lock the three-dimensional movement, and has the effect of providing an inexpensive and stable performance knock-type writing instrument.
[0026]
【The invention's effect】
The configuration and operation of the knock type writing instrument of the present invention are as described above, and the function of the knock type writing instrument having a high safety and the effect of preventing an accident such as dirty clothes from occurring is obtained. In addition, since the writing tip can be raised and lowered only by a knocking operation, it is easy to use and the structure is simple, so that assembly is easy and inexpensive.
Furthermore, even if medium-low viscosity ink is filled, the ink backflow and direct current phenomenon do not occur, and the pen tip is kept dry and can provide a ballpoint refill without a seal cap. In this case, it is possible to provide a writing instrument that can be manufactured and can be stably mass-produced without worrying about the problem of defoaming failure and wiping off the grease at the rear end of the refill.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an entire refill storage structure as an embodiment of a knock type writing instrument of the present invention.
FIG. 2 is a longitudinal sectional view showing the entire refill projecting structure as an embodiment of the knock type writing instrument of the present invention.
FIG. 3 is an enlarged longitudinal sectional view showing a rear portion of the knock type writing instrument according to the embodiment.
FIG. 4 is a longitudinal sectional view showing the entire refill of the knock type writing instrument according to the embodiment.
FIG. 5 is an enlarged longitudinal sectional view showing a tip portion of the refill according to the embodiment.
FIG. 6 is a diagram for explaining the operation of the rotating cam mechanism of the knock type writing instrument according to the embodiment and the engaging relationship between the engaging surface of the clip ball and the engaging portion of the rotor.
[Explanation of symbols]
1 Refill
2 Fitting
3 Front shaft
4 Rear shaft
5 Chip elastic body
6 Air holes
7 Valve chamber
8 Check ball seat
9 Lead hole
10 Inner hole
11 Groove
12 chips
13 Tip ball
14 Channel section
14a Ball seat
14b Caulking section
15 Check ball
16 Ink receiving tube
17 Ink
18 followers
19 Follower Stick
20a Cam slope
20b Locking window
21 clips
21a Clip ball
21b Locking surface
21c Locking piece
22 Rotor
22a Cam slope a
22b Locking part
22c Cam slope c
23 Knock stick
23a Cam slope
23b Anti-rotation
24 Return spring
25 Tip sealant
26 Chamfering

Claims (3)

A rotating cam mechanism portion that is locked in a forward and backward position with respect to the shaft tube by a knocking operation is disposed behind the shaft tube, and a refill urged rearward by a return spring is provided in front of the rotating cam mechanism portion. The clip protruding from one side of the rear of the shaft tube forms a locking surface at the ball portion at the tip, and a window portion into which the ball portion fits appropriately is drilled on the side surface of the shaft tube, The cam slope is formed on the rotor at two axial positions that respectively meet the cam slope provided on the knock rod that moves back and forth without rotating and the cam slope provided on the inner surface of the shaft cylinder or the parts fixed to the shaft cylinder. Further, the rotor is configured to have a projecting locking portion that locks with the clip ball portion locking surface, and the rotor is moved by the pressing action between the cam inclined surfaces by the advancement of the knocking rod accompanying the knocking operation. Rotate by a certain angle to lock the clip ball The engaging portion provided on the rotor is engaged or disengaged, and the writing tip of the refill is locked so as to be able to protrude and retract from the tip opening of the shaft tube, and the ball portion of the clip is in the engaged state. In a knock-type writing instrument constructed so that the engagement tip is disengaged when displaced in a direction away from the side surface and the writing tip is retractable from the tip opening, the rear end of the refill is the locking portion of the clip ball A knock-type writing instrument characterized in that it is configured to be provided further forward in the axial direction. The tip ball is always pressed against the inner edge of the tip end ball caulking that is prevented from coming off while the tip ball protrudes from the tip, so that the tip ball is always pressed by the spring inside the tip, and the close state is released when writing. In a refill of a ballpoint pen in which a medium-viscosity ink having a viscosity at room temperature of 10 to 5000 mPa · S is filled in an ink containing portion behind the joint portion to which the tip is fixed at the tip. 2. An air hole for air replacement is provided at the rear end of the storage tube, and the air replacement hole is substantially equal to or larger than the minimum inner diameter of the ink storage tube. Ballpoint pen type knocking writing instrument as described in 1. Air receiving means such as holes, grooves, and protrusions are provided on the receiving surface of the rotor, which is in contact with the rear end of the refill ink storage tube, which is always pressed axially rearward by a spring. The knock-type writing instrument according to claim 1 or 2, wherein a chamfering is provided on at least one of an inner diameter and an outer diameter so as to reduce a contact resistance between the ink storage tube and the rotor.

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