Patent Application
20250033402
The present invention relates to a writing implement. Specifically, the present invention relates to a direct liquid type writing implement including a pen tip, an ink tank that directly retains ink, an ink retention member that includes the pen tip at a front-end portion thereof, is provided on a front side of the ink tank, and temporarily retains overflow ink accompanying an increase in pressure inside the ink tank, and an ink guiding member that is provided inside the ink retention member and supplies the ink from the ink tank to the pen tip.
In the related art, Patent Document 1 discloses a configuration in which a vent hole communicating with a through hole is provided in a side surface portion of an ink retainer in which the through hole for attaching an ink guiding core is formed. Patent Document 2 discloses a configuration in which a through hole is provided from an outer surface of a collector toward an inner hole of the collector.
Japanese Patent No. 4212714
Japanese Patent No. 4666872
In the above Patent Document 1, when ink in an ink chamber freezes (especially when the ink freezes with a pen tip facing downward), the volumetrically expanded ink in the ink chamber is pushed out through the through hole near the pen tip, and the pushed out ink cannot be reliably discharged from the vent hole to an outer surface of the ink retainer, which may cause the ink to leak from the pen tip.
Similarly to the above, in Patent Document 2, when ink in an ink tank freezes (especially when the ink freezes with a pen tip facing downward), the volumetrically expanded ink in the ink tank is pushed out through the inner hole near the pen tip, and the pushed out ink cannot be reliably discharged from the through hole to the outer surface of the collector, which may cause the ink to leak from the pen tip.
The present invention has been made to solve the problems in the related art and aims to provide a direct liquid type writing implement that can reliably prevent ink from leaking from a pen tip even if the ink inside freezes. In the present invention, “forward” indicates the pen tip side, and “rearward” indicates a side opposite thereto. Definitions of directions in the present invention will be described separately later.
The present invention provides the following means to solve the above problems.
A writing implement including a pen tip, an ink tank that directly retains ink, an ink retention member that includes the pen tip at a front-end portion thereof, is provided on a front side of the ink tank, and temporarily retains overflow ink accompanying an increase in pressure inside the ink tank, and an ink guiding member that is provided inside the ink retention member and supplies the ink from the ink tank to the pen tip, wherein the ink retention member includes a plurality of plate-shaped comb teeth formed at intervals on an outer surface thereof, a plurality of ink retention grooves that are formed between the comb teeth and temporarily retain the ink, an axially extending slit-shaped ink guiding groove that communicates with the ink tank and communicates with each of the ink retention grooves, an ink retention portion that is formed on an outer surface thereof in a front to rear direction and includes the ink retention grooves and the ink guiding groove, and an inner hole that is provided to extend in an axial direction and has the ink guiding member provided therein, the ink retention member includes a first horizontal hole that opens radially outward and communicates with the inner hole, the first horizontal hole and the ink guiding groove are formed not to communicate with each other in a transverse cross-section, and the first horizontal hole is provided in a rear half portion of the ink retention portion.
According to the writing implement of the above aspect, even if the ink in the ink tank freezes with the pen tip facing downward, the ink pushed out from the ink tank can be quickly and reliably discharged to the outside from the first horizontal hole near the ink tank before it reaches the vicinity of the pen tip. As a result, it is possible to reliably prevent the ink from leaking from the pen tip when the ink in the ink tank freezes.
The writing implement according to Aspect 1, wherein the ink retention member includes a second horizontal hole that is disposed forward from the first horizontal hole, opens radially outward, and communicates with the inner hole, and the second horizontal hole and the ink guiding groove are formed not to communicate with each other in the transverse cross-section.
According to the writing implement of the above aspect, when the ink freezes, an amount of the frozen ink corresponding to the volumetric expansion in the ink tank is mainly discharged to the outside through the first horizontal hole, and the amount of the frozen ink corresponding to the volumetric expansion inside the inner hole is discharged to the outside through the second horizontal hole. Thus, it is possible to more reliably prevent the ink from leaking from the pen tip when the ink freezes. In addition, according to the writing implement of the above aspect, when the ink in the ink tank is first drawn out to the pen tip (that is, at the time of initial ink discharging), the residual air inside the inner hole is reliably discharged to the outside through the second horizontal hole, and the ink can be quickly drawn from the ink tank to the pen tip.
The writing implement according to aspect 1 or 2, wherein the first horizontal hole is provided to penetrate at least one comb tooth of the comb teeth in the axial direction and communicates with the ink retention grooves adjacent to the comb tooth.
According to the writing implement of the above aspect, a sufficient opening area of the first horizontal hole can be secured, and when the ink freezes, the overflow ink from the first horizontal hole can be reliably discharged to the outside. Further, according to the writing implement of the above aspect, when the ink freezes, the overflow ink from the first horizontal hole can be discharged into the ink retention grooves. Thus, when the pressure inside the ink tank is reduced after the ink thaws, the ink in the ink retention grooves is quickly collected into the ink tank through the ink guiding groove. As a result, ink remaining in the vicinity of the first horizontal hole can be avoided.
The writing implement according to aspect 2, wherein the second horizontal hole is provided to penetrate at least one comb tooth of the comb teeth in the axial direction and communicates with the ink retention grooves adjacent to the comb tooth.
According to the writing implement of the above aspect, a sufficient opening area of the second horizontal hole can be secured, and when the ink freezes, the overflow ink from the second horizontal hole can be reliably discharged to the outside. Further, according to the writing implement of the above aspect, when the ink freezes, the overflow ink from the second horizontal hole can be discharged into the ink retention grooves. Thus, when the pressure inside the ink tank is reduced after the ink thaws, the ink in the ink retention grooves is quickly collected into the ink tank through the ink guiding groove. As a result, ink remaining in the vicinity of the second horizontal hole can be avoided. In particular, when the first horizontal hole and the second horizontal hole are provided to penetrate at least one comb tooth in the axial direction and communicate with the ink retention grooves adjacent to the comb tooth, the following effects can be obtained. That is, when the ink freezes, the overflow ink inside the inner hole can be reliably discharged to the outside, and after the ink thaws, ink remaining in the vicinity of the first horizontal hole can be avoided, and ink remaining in the vicinity of the second horizontal hole can be avoided.
A writing implement according to any one of aspects 1 to 4, wherein the first horizontal hole includes a first inner opening portion that opens into the inner hole, a first outer opening portion that opens radially outward, and a first step portion that is disposed between the first inner opening portion and the first outer opening portion and faces radially outward.
According to the writing implement of the above aspect, the first step portion can prevent the ink discharged from the inner hole to the outside through the first horizontal hole from returning to the inside of the inner hole. According to the above-described aspect, it is possible to prevent problems such as the ink leaking from the pen tip due to the overflow ink unintentionally returning from the first horizontal hole to the inner hole.
More specifically, the overflow ink discharged from the inner hole to the outside through the first horizontal hole is prevented from flowing back into the inner hole due to the function of the first step portion. Then, the overflow ink stably flows from the first horizontal hole to the ink guiding groove through the ink retention grooves due to the capillary force. The overflow ink is efficiently collected from the ink guiding groove into the ink tank.
A writing implement according to aspect 2 or 4, wherein the second horizontal hole includes a second inner opening portion that opens into the inner hole, a second outer opening portion that opens radially outward, and a second step portion that is disposed between the second inner opening portion and the second outer opening portion and faces radially outward.
According to the writing implement of the above aspect, the second step portion can prevent the ink discharged from the inner hole to the outside through the second horizontal hole from returning to the inside of the inner hole. According to the above-described aspect, it is possible to prevent problems such as ink leaking from the pen tip due to overflow ink unintentionally returning from the second horizontal hole to the inner hole.
More specifically, the overflow ink discharged from the inner hole to the outside through the second horizontal hole is prevented from flowing back into the inner hole due to the function of the second step portion. Then, the overflow ink stably flows from the second horizontal hole to the ink guiding groove through the ink retention grooves due to the capillary force. The overflow ink is efficiently collected from the ink guiding groove into the ink tank.
A writing implement including a pen tip, an ink tank that directly retains ink, an ink retention member that includes the pen tip at a front-end portion thereof, is provided on a front side of the ink tank, and temporarily retains overflow ink accompanying an increase in pressure inside the ink tank, and an ink guiding member that is provided inside the ink retention member and supplies the ink from the ink tank to the pen tip, wherein the ink retention member includes a plurality of plate-shaped comb teeth formed at intervals on an outer surface thereof, a plurality of ink retention grooves that are formed between the comb teeth and temporarily retain the ink, an axially extending slit-shaped ink guiding groove that communicates with the ink tank and communicates with each of the ink retention grooves, and an inner hole that is provided to extend in an axial direction and has the ink guiding member provided therein, the ink retention member includes a horizontal hole that opens radially outward and communicates with the inner hole, the horizontal hole and the ink guiding groove are formed not to communicate with each other in a transverse cross-section, and the horizontal hole is provided to penetrate at least one comb tooth of the comb teeth in the axial direction and communicates with the ink retention grooves adjacent to the comb tooth.
According to the writing implement of the above aspect, a sufficient opening area of the horizontal hole can be secured, and when the ink freezes, the overflow ink from the horizontal hole can be reliably discharged to the outside. Further, according to the writing implement of the above aspect, when the ink freezes, the overflow ink from the horizontal hole can be discharged into the ink retention grooves. Thus, when the pressure inside the ink tank is reduced after the ink thaws, the ink in the ink retention grooves is quickly collected into the ink tank through the ink guiding groove. As a result, ink remaining in the vicinity of the horizontal hole can be avoided. In addition, in the above aspect, the horizontal hole may be a single hole or may be a plurality of holes in a front to rear direction. Further, in the above aspect, the position at which the horizontal hole is formed may be any of a front half portion of the ink retention portion, a central portion of the ink retention portion, or a rear half portion of the ink retention portion.
The writing implement according to aspect 7, wherein the horizontal hole includes an inner opening portion that opens into the inner hole, an outer opening portion that opens radially outward, and a step portion that is disposed between the inner opening portion and the outer opening portion and faces radially outward.
A writing implement including a pen tip, an ink tank that directly retains ink, an ink retention member that includes the pen tip at a front-end portion thereof, is provided on a front side of the ink tank, and temporarily retains overflow ink accompanying an increase in pressure inside the ink tank, and an ink guiding member that is provided inside the ink retention member and supplies the ink from the ink tank to the pen tip, wherein the ink retention member includes a plurality of plate-shaped comb teeth formed at intervals on an outer surface thereof, a plurality of ink retention grooves that are formed between the comb teeth and temporarily retain the ink, an axially extending slit-shaped ink guiding groove that communicates with the ink tank and communicates with each of the ink retention grooves, and an inner hole that is provided to extend in an axial direction and has the ink guiding member provided therein, the ink retention member includes a horizontal hole that opens radially outward and communicates with the inner hole, the horizontal hole and the ink guiding groove are formed not to communicate with each other in a transverse cross-section, and the horizontal hole includes an inner opening portion that opens into the inner hole, an outer opening portion that opens radially outward, and a step portion that is disposed between the inner opening portion and the outer opening portion and faces radially outward.
According to the writing implement of the above aspect, the step portion can prevent the ink discharged from the inner hole to the outside through the horizontal hole from returning to the inside of the inner hole. According to the above-described aspect, it is possible to prevent problems such as ink leaking from the pen tip due to the overflow ink unintentionally returning from the horizontal hole to the inner hole.
Here, in known writing implements, there is also room for improvement in terms of efficiently returning overflow ink to an ink tank (hereinafter referred to as another problem). In this regard, according to the writing implement of the above aspect, the overflow ink discharged to the outside from the horizontal hole can efficiently return to the ink tank. Accordingly, it is possible to solve the other problem as well.
The writing implements according to the above aspects of the present invention can reliably prevent the ink from leaking from the pen tip even if the ink inside freezes.
A writing implement 1 according to an embodiment of the present invention is shown in
As shown in
Definitions of directions used in the present embodiment will be explained. In the present embodiment, a direction in which the central axis O of the writing implement 1 extends, that is, a direction along the central axis O, will be referred to as a front to rear direction. Also, the front to rear direction may be referred to as an axial direction or a longitudinal direction. In the front to rear direction (the axial direction or the longitudinal direction), the ink tank 21 and the pen tip 3 are disposed at different positions with respect to each other. In the front to rear directions, a side in a direction from the ink tank 21 to the pen tip 3 will be referred to as a front side, and a side in a direction from the pen tip 3 to the ink tank 21 will be referred to as a rear side. Further, the front side may also be referred to as one side in the axial direction or one side in the longitudinal direction. The rear side may also be referred to as the other side in the axial direction or the other side in the longitudinal direction.
A direction perpendicular to the central axis O will be referred to as a radial direction. In the radial direction, a direction approaching the central axis O will be referred to as radially inward, and a direction separating from the central axis O will be referred to as radially outward. A direction rotating around the central axis O will be referred to as a circumferential direction.
Each constituent element of the writing implement I will be explained in detail.
The pen tip 3 is disposed at a front-end portion of the writing implement 1. The pen tip 3 extends in the front to rear direction. Examples of the pen tip 3 include a ballpoint pen tip with a rotatable ball at its front end, a pen body made of a processed fiber body or a porous body, a metal plate pen body with a slit in its front end such as a fountain pen, a pen body made of an injection-molded synthetic resin body having a capillary gap in the axial direction, or the like. The pen tip 3 of the present embodiment includes a ballpoint pen tip 31 and a tip holder 32 that holds the ballpoint pen tip 31. A first relay core 31a is provided within the ballpoint pen tip 31, and a second relay core 32a is provided within the tip holder 32. A rear end of the first relay core 31a and a front end of the second relay core 32a are connected to each other, and a rear end of the second relay core 32a and a front end of the ink guiding member 5 are connected to each other. The first relay core 31a and the second relay core 32a are members including capillary gaps in the axial direction, and are made of, for example, an injection-molded synthetic resin body, a processed fiber body, or a porous body.
The shaft cylinder 2 is disposed in a portion of the writing implement 1 other than the front-end portion. The shaft cylinder 2 extends in the front to rear direction. The shaft cylinder 2 is configured of a bottomed cylindrical body with an open front end and a closed rear end and is obtained by injection molding of a synthetic resin (for example, polypropylene). The ink retention member 4 is disposed inside the front portion of the shaft cylinder 2. The ink tank 21 is formed inside the shaft cylinder 2 on the rear side of the ink retention member 4. Liquid ink is directly retained in the ink tank 21. The ink is, for example, a water-based ink and has a property of freezing when the temperature drops to a predetermined temperature.
The ink retention member 4 is disposed between the pen tip 3 and the ink tank 21 in the front to rear direction. Specifically, the ink retention member 4 is provided on a rear side of the pen tip 3 and on a front side of the ink tank 21. The ink retention member 4 has a substantially tubular shape and extends in the front to rear direction. The ink retention member 4 is a member that can temporarily retain and hold ink that overflows from the ink tank 21. Also, in the present embodiment, the ink that overflows from the ink tank 21 may be referred to as overflow ink.
The ink retention member 4 includes a pen tip holding portion 42 disposed in a front-end portion of the ink retention member 4, a plurality of substantially disk-shaped comb teeth 41 disposed rearward from the pen tip holding portion 42, an inner hole 45 that is formed in an axial center portion of the ink retention member 4 and penetrates the ink retention member 4 in the axial direction, a cylindrical portion 49 to which the plurality of comb teeth 41 are connected, a plurality of ink retention grooves 43 that temporarily retain the ink, an ink guiding groove 44 that communicates with the ink tank 21, an ink retention portion 40, and horizontal holes 46 and 47. In the present embodiment, the ink retention member 4 has a plurality of horizontal holes 46 and 47. The plurality of horizontal holes 46 and 47 include a first horizontal hole 46 and a second horizontal hole 47 located away from the first horizontal hole 46 toward the front side.
The pen tip 3 is fixed to the pen tip holding portion 42. The pen tip holding portion 42 includes an attachment hole that communicates with the inner hole 45, and the pen tip 3 is press-fitted into the attachment hole. Specifically, the tip holder 32 holding the ballpoint pen tip 31 is press-fitted into the attachment hole. The ink guiding member 5 is inserted into the inner hole 45. That is, the ink guiding member 5 is provided inside the inner hole 45.
The ink retention member 4 is an injection-molded body of a synthetic resin (for example, ABS resin), and the comb teeth 41 and the pen tip holding portion 42 are integrally formed. The ink retention member 4 has a function of temporarily holding surplus ink (overflow ink) from the ink tank 21 when the pressure inside the ink tank 21 increases. In addition, the ink retention member 4 is a member that has a function of returning the temporarily held ink (overflow ink) to the ink tank 21 when the pressure inside the ink tank 21 decreases.
The cylindrical portion 49 has a cylindrical shape centered on the central axis O and extends in the front to rear direction. A front-end portion of the cylindrical portion 49 is connected to a rear end portion of the pen tip holding portion 42. The inner hole 45 penetrates the cylindrical portion 49 in the front to rear direction.
The plurality of comb teeth 41 each have a plate shape that extends in a direction perpendicular to the central axis O. A pair of plate surfaces of each of the comb teeth 41 face forward and rearward. The plurality of comb teeth 41 are formed on an outer surface of the ink retention member 4 at intervals in the front to rear direction. The comb teeth 41 have flange shapes that extend radially outward from an outer circumferential surface of the cylindrical portion 49. That is, radially inner end portions of the comb teeth 41 are connected to the outer circumferential surface of the cylindrical portion 49.
The plurality of comb teeth 41 are arranged at appropriate intervals in the front to rear direction, and each of the ink retention grooves 43 are formed between the respective comb teeth 41. A slit-shaped ink guiding groove 44 that extends in the axial direction and opens radially outward is formed in each of the plurality of comb teeth 41. The ink guiding grooves 44 provided in each of the comb teeth 41 are arranged side by side in the front to rear direction. Also, in the present embodiment, an overall shape of the plurality of ink guiding grooves 44 arranged in the front to rear direction may be referred to as (one) ink guiding groove 44. The ink guiding groove 44 communicates with each of the ink retention grooves 43 and extends in the axial direction. As shown in
As shown in
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The rear end flange portion 41a includes the ink guiding groove 44 that communicates with the ink retention grooves 43 on the front side and communicates with the ink tank 21 on the rear side. The ink guiding groove 44 of the rear end flange portion 41a is provided to extend in the axial direction, opens radially outward, and does not communicate with the inner hole 45. When the ink retention member 4 is inserted into a front end opening portion of the shaft cylinder 2, an outer circumferential surface of the rear end flange portion 41a fits into a front inner circumferential surface of the shaft cylinder 2, and the comb teeth 41 group located forward from the rear end flange portion 41a is maintained in a non-fitting state with an inner wall of the shaft cylinder 2. For this reason, gaps through which fluids such as ink and air can flow are provided between respective outer end portions of the plurality of comb teeth 41 and the inner circumferential surface of the shaft cylinder 2. By fitting the outer circumferential surface of the rear end flange portion 41a and the front inner circumferential surface of the shaft cylinder 2, the rear end flange portion 41a is deformed to contract radially inward. With this, a groove width, that is, a circumferential dimension, of the ink guiding groove 44 of the rear end flange portion 41a is formed to be smaller than a groove width of the ink guiding groove 44 of the plurality of comb teeth 41 forward from the rear end flange portion 41a.
As shown in
The intermediate flange portion 41b includes the ink guiding groove 44 and two air exchange grooves 48 formed on both sides of the ink guiding groove 44 in the circumferential direction to straddle the ink guiding groove 44. The ink guiding groove 44 is provided to penetrate the intermediate flange portion 41b in the axial direction, opens radially outward, and does not communicate with the inner hole 45. The two air exchange grooves 48 penetrate the intermediate flange portion 41b in the axial direction and open radially outward. The two air exchange grooves 48 included in the intermediate flange portion 41b have different positions in the circumferential direction from the air exchange grooves 48 included in each of the comb teeth 41. An outer surface of the intermediate flange portion 41b is fitted into an inner surface of the shaft cylinder 2.
As shown in
An air exchange groove 48 that extends in the axial direction and opens radially outward is formed in the front-end flange portion 41c. The air exchange groove 48 of the front-end flange portion 41c is formed on the same side as the air exchange grooves 48 of the comb teeth 41 group other than the intermediate flange portion 41b. Specifically, the air exchange groove 48 included in the front-end flange portion 41c and the air exchange grooves 48 included in each of the comb teeth 41 are arranged to overlap each other when viewed in the front to rear direction. The air exchange groove 48 of the front-end flange portion 41c has the same position in the circumferential direction as the air exchange grooves 48 of each of the comb teeth 41. The ink guiding groove 44 is not formed in the front-end flange portion 41c.
The ink guiding member 5 is a member that has a capillary gap in the axial direction and guides the ink from the ink tank 21 to the pen tip 3. That is, the ink guiding member 5 supplies the ink from the ink tank 21 to the pen tip 3. The ink guiding member 5 is made of, for example, an injection-molded synthetic resin body, a processed fiber body, or a porous body. The ink guiding member 5 connects the inside of the ink tank 21 and the pen tip 3. The ink guiding member 5 may be configured of a single member or a plurality of members. The ink guiding member 5 may protrude rearward into the ink tank 21. That is, the ink guiding member 5 may protrude rearward from a rear end surface of the ink retention member 4, and a portion (rear end portion) thereof may be disposed inside the ink tank 21. Also, a separate ink guiding member connected to the ink guiding member 5 in the inner hole 45 may be disposed inside the ink tank 21.
As shown in
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A shape of an opening portion of the first horizontal hole 46 is a rectangular shape when the first horizontal hole 46 is viewed from the outside in the radial direction, as shown in
Also, the first horizontal hole 46 may have any configuration as long as it is provided to penetrate at least one comb tooth 411 in the axial direction and opens radially outward. Further, the first horizontal hole 46 may be configured to communicate with the ink retention grooves 431 and 431a adjacent forwardly or rearwardly to at least one comb tooth 411 having the first horizontal hole 46. Preferably, a configuration in which the first horizontal hole 46 communicates with the plurality of ink retention grooves 431 and 431a adjacent forwardly and rearwardly to at least one comb tooth 411 having the first horizontal hole 46 may be exemplified. That is, the first horizontal hole 46 is provided to penetrate at least one comb tooth 411 (41) in the axial direction and communicates with the ink retention grooves 431 and 431a (43) adjacent to the comb tooth 411.
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Also, the second horizontal hole 47 may be configured to penetrate at least one comb tooth 412 in the axial direction and open radially outward. Further, the second horizontal hole 47 may be configured to communicate with the ink retention grooves 432 and 432a adjacent forwardly or rearwardly to at least one comb tooth 412 having the second horizontal hole 47. Preferably, a configuration in which the second horizontal hole 47 communicates with the plurality of ink retention grooves 432 and 432a adjacent forwardly and rearwardly to at least one comb tooth 412 having the second horizontal hole 47 is exemplified. That is, the second horizontal hole 47 is provided to penetrate at least one comb tooth 412 (41) in the axial direction and communicates with the ink retention grooves 432 and 432a (43) adjacent to the comb tooth 412.
Configurations of the horizontal holes 46 and 47 will be explained in more detail. As shown in
Specifically, as shown in
The first inner opening portion 46a is disposed in a radially inner end portion of the first horizontal hole 46 and connected to the inner hole 45. The first outer opening portion 46b is disposed radially outward from the first inner opening portion 46a and communicates with the air exchange groove 48 and the ink retention grooves 431 and 431a. In the present embodiment, a dimension in the width direction (circumferential direction) of the first outer opening portion 46b is greater than a dimension in the width direction (the length T1) of the first inner opening portion 46a. In addition, a dimension in the longitudinal direction (front to rear direction) of the first outer opening portion 46b is the same as a dimension in the longitudinal direction (the length S1) of the first inner opening portion 46a.
The first step portion 46c connects the first inner opening portion 46a to the first outer opening portion 46b. In the present embodiment, a pair of first step portions 46c are provided at both end portions in the width direction (circumferential direction) of an inner wall of the first horizontal hole 46. The pair of first step portions 46c are disposed on a pair of longer sides among four sides of the first horizontal hole 46, which form a rectangular opening shape, and extend in the axial direction (see
The pair of first step portions 46c each have a planar shape that extends in directions perpendicular to a predetermined radial direction in which the first horizontal hole 46 extends. However, the present invention is not limited thereto, and although not particularly illustrated, the pair of first step portions 46c may have a planar shape that is inclined with respect to the predetermined radial direction and extends radially outward as they are separated from each other in the width direction. Alternatively, the pair of first step portions 46c may have a planar shape that is inclined with respect to the predetermined radial direction and extends radially inward as they are separated from each other in the width direction. Also, the first step portion 46c is not limited to a planar shape, but may have a convex curved shape, a concave curved shape, or the like.
As shown in
The second inner opening portion 47a is disposed in a radially inner end portion of the second horizontal hole 47 and connected to the inner hole 45. The second outer opening portion 47b is disposed radially outward from the second inner opening portion 47a and communicates with the air exchange groove 48 and the ink retention grooves 432 and 432a. In the present embodiment, the dimension in the width direction (circumferential direction) of the second outer opening portion 47b is greater than a dimension in the width direction (the length T2) of the second inner opening portion 47a. Further, a dimension in the longitudinal direction (front to rear direction) of the second outer opening portion 47b is the same as a dimension in the longitudinal direction (the length S2) of the second inner opening portion 47a.
The second step portion 47c connects the second inner opening portion 47a to the second outer opening portion 47b. In the present embodiment, a pair of second step portions 47c are provided at both end portions of an inner wall of the second horizontal hole 47 in the width direction (circumferential direction). The pair of second step portions 47c are disposed on a pair of longer sides among four sides of the second horizontal hole 47, which form a rectangular opening shape, and extend in the axial direction (see
The pair of second step portions 47c each have a planar shape that extends in a direction perpendicular to a predetermined radial direction in which the second horizontal hole 47 extends. However, the present invention is not limited thereto, and although not particularly illustrated, the pair of second step portions 47c may have a planar shape that is inclined with respect to the predetermined radial direction and extends radially outward as they are separated from each other in the width direction. Alternatively, the pair of second step portions 47c may have a planar shape that is inclined with respect to the predetermined radial direction and extends radially inward as they are separated from each other in the width direction. Further, the second step portion 47c is not limited to a planar shape, but may have a convex curved shape, a concave curved shape, or the like.
As explained above, the writing implement 1 of the present embodiment is the writing implement 1 including the pen tip 3, the ink tank 21 that directly retains the ink, the ink retention member 4 that includes the pen tip 3 at the front-end portion, is provided on the front side of the ink tank 21, and temporarily retains the overflow ink accompanying an increase in pressure in the ink tank 21, and the ink guiding member 5 that is provided inside the ink retention member 4 and supplies the ink from the ink tank 21 to the pen tip 3, wherein the ink retention member 4 includes the plurality of plate-shaped comb teeth 41 formed at intervals on the outer surface, the plurality of ink retention grooves 43 that are formed between the comb teeth 41 and temporarily retain the ink, the axially extending slit-shaped ink guiding groove 44 that communicates with the ink tank 21 and communicates with each of the ink retention grooves 43, the ink retention portion 40 that is formed on the outer surface in the front to rear direction and includes of the ink retention grooves 43 and the ink guiding groove 44, and the inner hole 45 that is provided to extend in the axial direction and has the ink guiding member 5 provided therein, the ink retention member 4 includes the first horizontal hole 46 that opens radially outward and communicates with the inner hole 45, the first horizontal hole 46 and the ink guiding groove 44 are formed not to communicate with each other in the transverse cross-section, and the first horizontal hole 46 is provided in the rear half portion of the ink retention portion 40.
Thus, even if the ink in the ink tank 21 freezes with the pen tip 3 facing downward, the writing implement 1 of the present embodiment can quickly and reliably discharge the ink to the outside (the ink retention portion 40) from the first horizontal hole 46 near the ink tank 21 before the ink pushed out from the ink tank 21 reaches the vicinity of the pen tip 3. As a result, ink leakage from the pen tip 3 when the ink in the ink tank 21 freezes can be reliably prevented.
In the writing implement 1 of the present embodiment, the ink retention member 4 includes the second horizontal hole 47 that is disposed forward from the first horizontal hole 46, opens radially outward, and communicates with the inner hole 45, and the second horizontal hole 47 and the ink guiding groove 44 are formed not to communicate with each other in the transverse cross-section.
Thus, in the writing implement 1 of the present embodiment, when the ink freezes, the amount of volumetric expansion of the frozen ink in the ink tank 21 is mainly discharged to the outside through the first horizontal hole 46, and the amount of volumetric expansion of the frozen ink inside the inner hole 45 is discharged to the outside through the second horizontal hole 47. As a result, ink leakage from the pen tip 3 when the ink freezes can be more reliably prevented. In addition, in the writing implement 1 of the present embodiment, when the ink in the ink tank 21 is first drawn out to the pen tip 3 (that is, at the time of initial ink discharging), the residual air inside the inner hole 45 can be reliably discharged to the outside from the second horizontal hole 47, and the ink can be quickly drawn out from the ink tank 21 to the pen tip 3. Although the writing implement 1 of the present embodiment may have a configuration in which only the first horizontal hole 46 is provided, it is preferable to provide the second horizontal hole 47.
In the writing implement 1 of the present embodiment, the first horizontal hole 46 is provided to penetrate at least one comb tooth 411 in the axial direction and communicates with the ink retention grooves 431 and 431a adjacent to the comb tooth 411. Specifically, the first horizontal hole 46 is provided to penetrate the plurality of comb teeth 411 in the axial direction and communicates with the plurality of ink retention grooves 431 and 431a adjacent forwardly and rearwardly to each of the comb teeth 411.
Thus, the writing implement 1 of the present embodiment can secure a sufficient opening area of the first horizontal hole 46, and when the ink freezes, the overflow ink from the first horizontal hole 46 can be reliably discharged to the outside. Further, when the ink freezes, the writing implement 1 according to the present embodiment can discharge the overflow ink from the first horizontal hole 46 into the ink retention grooves 431 and 431a (specifically, the plurality of ink retention grooves 431 and 431a). Thus, when the pressure inside the ink tank 21 is reduced after the ink thaws, the ink in the ink retention grooves 431 and 431a is quickly collected into the ink tank 21 through the ink guiding groove 44. As a result, ink remaining in the vicinity of the first horizontal hole 46 can be avoided.
In the writing implement 1 of the present embodiment, the second horizontal hole 47 is provided to penetrate at least one comb tooth 412 in the axial direction and communicates with ink retention grooves 432 and 432a adjacent to the comb tooth 412. Specifically, the second horizontal hole 47 is provided to penetrate the plurality of comb teeth 412 in the axial direction and communicates with the plurality of ink retention grooves 432 and 432a adjacent forwardly and rearwardly to each of the comb teeth 412.
Thus, the writing implement 1 of the present embodiment can secure a sufficient opening area of the second horizontal hole 47, and when the ink freezes, the overflow ink from the second horizontal hole 47 can be reliably discharged to the outside. Further, when the ink freezes, the writing implement 1 of the present embodiment can discharge the overflow ink from the second horizontal hole 47 into the ink retention grooves 432 and 432a (specifically, the plurality of ink retention grooves 432 and 432a). Thus, when the pressure inside the ink tank 21 is reduced after the ink thaws, the ink in the ink retention grooves 432 and 432a is quickly collected into the ink tank 21 through the ink guiding groove 44. As a result, ink remaining in the vicinity of the second horizontal hole 47 can be avoided.
In particular, in the writing implement 1 of the present embodiment, the first horizontal hole 46 and the second horizontal hole 47 are provided to penetrate at least one comb tooth 41 in the axial direction and communicate with the ink retention grooves 43 adjacent to the comb tooth 41. Thus, when the ink freezes, the overflow ink inside the inner hole 45 can be reliably discharged to the outside, and after the ink thaws, ink remaining in the vicinity of the first horizontal hole 46 and ink remaining in the vicinity of the second horizontal hole 47 can be avoided.
In the writing implement 1 of the present embodiment, the first horizontal hole 46 includes the first inner opening portion 46a that opens into the inner hole 45, the first outer opening portion 46b that opens radially outward, and the first step portion 46c that is disposed between the first inner opening portion 46a and the first outer opening portion 46b and faces radially outward.
Thus, in the writing implement 1 of the present embodiment, the first step portion 46c prevents the ink discharged from the inner hole 45 to the outside through the first horizontal hole 46 from returning to the inside of the inner hole 45. According to the present embodiment, it is possible to prevent problems such as ink leaking from the pen tip 3 due to the overflow ink unintentionally returning from the first horizontal hole 46 to the inner hole 45.
As flows of the ink are shown by arrows in
In the writing implement 1 of the present embodiment, the second horizontal hole 47 includes the second inner opening portion 47a that opens into the inner hole 45, the second outer opening portion 47b that opens radially outward, and the second step portion 47c that is disposed between the second inner opening portion 47a and the second outer opening portion 47b and faces radially outward.
Thus, in the writing implement 1 of the present embodiment, the second step portion 47c can prevent the ink discharged from the inner hole 45 to the outside through the second horizontal hole 47 from returning to the inside of the inner hole 45. According to the present embodiment, it is possible to prevent problems such as ink leaking from the pen tip 3 due to the overflow ink unintentionally returning from the second horizontal hole 47 to the inner hole 45.
As flows of the ink are shown by arrows in
The writing implement 1 of the present embodiment is the writing implement 1 including the pen tip 3, the ink tank 21 that directly retains the ink, the ink retention member 4 that includes the pen tip 3 at the front-end portion, is provided on the front side of the ink tank 21, and temporarily retains the overflow ink accompanying an increase in pressure in the ink tank 21, and the ink guiding member 5 that is provided inside the ink retention member 4 and supplies the ink from the ink tank 21 to the pen tip 3, wherein the ink retention member 4 includes the plurality of plate-shaped comb teeth 41 formed at intervals on the outer surface, the plurality of ink retention grooves 43 that are formed between the comb teeth 41 and temporarily retain the ink, the axially extending slit-shaped ink guiding groove 44 that communicates with the ink tank 21 and communicates with each of the ink retention grooves 43, and the inner hole 45 that is provided to extend in the axial direction and has the ink guiding member 5 provided therein, the ink retention member 4 includes the horizontal hole (the first horizontal hole 46 and/or the second horizontal hole 47) that opens radially outward and communicates with the inner hole 45, the horizontal holes 46 and 47 and the ink guiding groove 44 are formed not to communicate with each other in the transverse cross-section, and the horizontal holes 46 and 47 are provided to penetrate at least one comb tooth 41 in the axial direction and communicate with the ink retention grooves 43 adjacent to the comb tooth 41. Specifically, the horizontal holes 46 and 47 are provided to penetrate the plurality of comb teeth 41 in the axial direction and communicate with the plurality of ink retention grooves 43 adjacent forwardly and rearwardly to each of the comb teeth 41.
Thus, the writing implement 1 of the present embodiment can secure a sufficient opening area for the horizontal holes 46 and 47, and when the ink freezes, the overflow ink from the horizontal holes 46 and 47 can be reliably discharged to the outside. Further, when the ink freezes, the writing implement 1 of the present embodiment can discharge the overflow ink from the horizontal holes 46 and 47 into the ink retention grooves 43 (specifically, the plurality of ink retention grooves 43). Thus, when the pressure inside the ink tank 21 is reduced after the ink thaws, the ink in the ink retention grooves 43 is quickly collected into the ink tank 21 through the ink guiding groove 44. As a result, ink remaining in the vicinity of the horizontal holes 46 and 47 can be avoided.
Also, in the present embodiment, the number of horizontal holes 46 and 47 provided and the positions thereof are not limited to the above-described embodiment. That is, the numbers, the positions, and the like of the horizontal holes 46 and 47 that are provided to penetrate at least one comb tooth 41 in the axial direction and communicate with the ink retention grooves 43 adjacent to the comb tooth 41 are not limited to the present embodiment. For example, a configuration in which the horizontal holes are provided in two locations on the front and rear sides, a configuration in which only one horizontal hole is provided in the rear half portion of the ink retention portion 40, a configuration in which only one horizontal hole is provided in a central portion of the ink retention portion 40, a configuration in which only one horizontal hole is provided in the front half portion of the ink retention portion 40, and the like can be exemplified.
In the writing implement 1 of the present embodiment, the horizontal holes 46 and 47 include the inner opening portions 46a and 47a that open into the inner hole 45, the outer opening portions 46b and 47b that open radially outward, and the step portions 46c and 47c that are disposed between the inner opening portions 46a and 47a and the outer opening portions 46b and 47b and face radially outward.
Also, the writing implement 1 of the present embodiment is the writing implement 1 including the pen tip 3, the ink tank 21 that directly retains the ink, the ink retention member 4 that includes the pen tip 3 at the front-end portion, is provided on the front side of the ink tank 21, and temporarily retains the overflow ink accompanying an increase in pressure in the ink tank 21, and the ink guiding member 5 that is provided inside the ink retention member 4 and supplies the ink from the ink tank 21 to the pen tip 3, wherein the ink retention member 4 includes the plurality of plate-shaped comb teeth 41 formed at intervals on the outer surface, the plurality of ink retention grooves 43 that are formed between the comb teeth 41 and temporarily retain the ink, the axially extending slit-shaped ink guiding groove 44 that communicates with the ink tank 21 and communicates with each of the ink retention grooves 43, and the inner hole 45 that is provided to extend in the axial direction and has the ink guiding member 5 provided therein, the ink retention member 4 includes the horizontal hole (the first horizontal hole 46 and/or the second horizontal hole 47) that opens radially outward and communicates with the inner hole 45, the horizontal holes 46 and 47 and the ink guiding groove 44 are formed in non-communicating with each other in the transverse cross-section, and the horizontal holes 46 and 47 includes the inner opening portions 46a and 47a that open into the inner hole 45, the outer opening portions 46b and 47b that open radially outward, and the step portions 46c and 47c that are disposed between the inner opening portions 46a and 47a and the outer opening portions 46b and 47b and face radially outward.
Thus, in the writing implement 1 of the present embodiment, the ink discharged from the inner hole 45 to the outside through the horizontal holes 46 and 47 can be prevented from returning to the inside of the inner hole 45 due to the step portions 46c and 47c. According to the present embodiment, it is possible to prevent problems such as ink leaking from the pen tip 3 due to the overflow ink unintentionally returning from the horizontal holes 46 and 47 to the inner hole 45.
Here, in known writing implements, there is also room for improvement in terms of efficiently returning overflow ink to an ink tank (hereinafter referred to as another problem). In this regard, according to the writing implement 1 of the present embodiment, the overflow ink discharged to the outside from the horizontal holes 46 and 47 can be efficiently returned to the ink tank 21. Accordingly, it is possible to solve the other problem as well.
Next, with reference to
In the first modified example, as shown in
Also in the first modified example, the same effects as in the above-described embodiment can be obtained. Further, in the first modified example, the shape of the mold for molding the ink retention member 4 can be simplified.
Next, with reference to
In the second modified example, as shown in
Also in the second modified example, the same effects as in the above-described embodiment can be obtained. Further, in the second modified example, the overflow ink discharged from the inner hole 45 to the outside (ink retention portion 40) through the horizontal holes 46 and 47 can be more stably inhibited from flowing back into the inner hole 45.
The present invention may include combinations of the configurations described in the above-described embodiment and modified examples, and additions, omissions, substitutions, and other changes of the configurations may be made without departing from the spirit of the present invention. Further, the present invention is not limited by the embodiment and the like described above and is limited only by the scope of the claims.
According to the writing implement of the present invention, even if the ink inside freezes, ink leakage from the pen tip can be reliably prevented. Accordingly, it has industrial applicability.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-198947 | Dec 2021 | JP | national |
This is the U.S. national stage of application No. PCT/JP2022/044669, filed on Dec. 5, 2022. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Japanese Application No. 2021-198947, filed Dec. 8, 2021, the disclosure of which is also incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/044669 | 12/5/2022 | WO |
