JP2020163591A - Ink inhaler - Google Patents

Abstract

To provide an ink inhaler capable of promoting the inflow of air into the hole of the piston member of air and smoothly flowing out the ink in the hole of the piston member into the ink storage portion.SOLUTION: An ink inhaler 20 includes a main cylinder 30 having a reduced diameter portion 31 on the inner surface and defining an ink storage portion 21 behind the reduced diameter portion 31, a piston member 50 arranged so as to be movable back and forth with respect to the main cylinder 30, a pipe 70 that extends through the reduced diameter portion 31 and extends inside the main cylinder 30 and is held so as to be movable back and forth with respect to the piston member 50, and a fixed piece member 80 fixed to the pipe 70 behind the reduced diameter portion 31. The piston member 50 is provided with a hole 57 through which the pipe 70 retracts and a partition wall 58 that closes the front of the hole 57. The partition wall 58 is provided with a through hole 59 through which the pipe 70 is inserted, and a plurality of grooves 59a that communicate with the through hole 59 and extend in the axial direction.SELECTED DRAWING: Figure 2

Description

The present invention relates to an ink inhaler used in a writing instrument such as a fountain pen.

Conventionally, in writing instruments such as fountain pens, an ink inhaler that sucks ink inside to store the ink and supplies the ink to the pen tip is used at the time of writing. The ink inhaler has an ink accommodating portion and an ink inhaling mechanism for sucking ink into the ink accommodating portion.

The ink inhalation mechanism usually has a mechanism that generates a negative pressure in the ink inhaler and sucks ink by utilizing the pressure difference between the inside of the ink inhaler and the outside. As a method of generating a negative pressure in the ink inhaler, for example, the operating member is linearly operated backward to move the piston member connected to the front of the operating member backward, so that the negative pressure is generated in the ink inhaler. Sliding type that generates pressure, rotary type that generates negative pressure in the ink inhaler by rotating the operating member around the axis and moving the piston member screwed with the operating member backward, at the rear of the ink inhaler A push type or the like that generates a negative pressure in the ink inhaler by pressing the provided piston member forward and then opening the member can be mentioned. In particular, the push-type ink inhaler can reduce the length of the operating member as compared with the slide-type or rotary-type ink inhaler. This makes it possible to reduce the size of the ink inhaler having the same capacity and to increase the capacity of the ink inhaler having the same capacity.

In Patent Document 1, an ink storage cylinder having a reduced diameter portion (inner stage) and an ink storage chamber, a piston member arranged at the rear portion of the ink storage cylinder, and a piston member arranged in the ink storage cylinder and held by the piston member. An ink suction device including a pipe and a piece fixed to the pipe is disclosed. In the ink suction device disclosed in Patent Document 1, a movable piece member is provided behind the piece, whereby when the pen is pointed downward from the state where the pen is directed upward, the movable piece member due to gravity is provided. By advancing, the ink can also advance and move to the pen core side, which has an advantage that writing can be performed immediately.

JP-A-2017-209863

In the conventional push-type ink inhaler, the ink may not flow out smoothly to the pen tip, or the ink may not be removed when cleaning the ink inhaler. As a result of diligent studies by the present inventors on the cause of this, it was found that the conventional push-type ink inhaler has the following problems.

In the conventional push-type ink inhaler, ink accumulates in the hole of the piston member where the pipe retracts when sucking ink, so that ink is not supplied to the pen tip side or when cleaning the ink inhaler. Ink that has entered the holes in the piston member may not be removed. As a result of further examination of this problem, when a partition wall is provided in front of the hole of the piston member, a pipe is inserted through the through hole provided in the partition wall, and the gap between the pipe and the through hole is not sufficient, this problem is solved. It was found that Specifically, the air in the ink container enters the hole of the piston member through the gap between the pipe and the through hole, and the ink contained in the hole of the piston member flows out to the ink container. It has been found that when the gap between the ink and the through hole is narrow, it becomes difficult for air to enter the hole of the piston member, which causes the above-mentioned problem. Further, when a protrusion formed on the pipe so as not to fall out of the through hole closes the through hole, it becomes more difficult for air in the ink accommodating portion to enter the hole of the piston member, and the ink entering the hole of the piston member accommodates ink. It has been found that it is difficult to leak into the room.

The present invention has been made in consideration of such a point, and it is possible to promote the inflow of air into the hole of the piston member and smoothly flow out the ink in the hole of the piston member into the ink accommodating portion. It is an object of the present invention to provide an ink inhaler.

The ink inhaler according to the present invention
A main cylinder having a reduced diameter portion on the inner surface and defining an ink accommodating portion behind the reduced diameter portion,
A piston member arranged so as to be movable back and forth with respect to the main cylinder,
A pipe that extends through the reduced diameter portion, extends inside the main cylinder, and is held so as to be movable back and forth with respect to the piston member.
A fixed piece member fixed to the pipe behind the reduced diameter portion is provided.
The piston member is provided with a hole through which the pipe retracts and a partition wall that closes the front of the hole.
The partition wall is provided with a through hole through which the pipe is inserted and a plurality of grooves extending in the axial direction communicating with the through hole.

The plurality of grooves in the ink inhaler of the present invention enable the ink in the holes of the piston member to smoothly flow out into the ink accommodating portion, and the number and size thereof are not limited. When the pen tip is a fountain pen, at least the pen tip in the through hole is used to facilitate the air in the ink accommodating portion from entering the hole of the piston member through the groove when writing with the surface of the pen tip facing upward. It is preferable to provide a groove in the surface direction of the ink.

According to the present invention, it is possible to provide an ink inhaler capable of promoting the inflow of air into the hole of the piston member and smoothly flowing out the ink in the hole of the piston member into the ink accommodating portion.

FIG. 1 is a diagram for explaining one embodiment according to the present invention, and is a diagram showing a cross section of a writing instrument incorporating an ink inhaler. FIG. 2 is an enlarged cross-sectional view of the ink inhaler, and in particular, the ink inhaler is shown in an open state. FIG. 3 is a diagram showing a cross section corresponding to the line BB of FIG. FIG. 4 is a cross-sectional view showing the ink inhaler in a state where its operating member is pushed forward. FIG. 5 is a view showing a state in which the ink inhaler is arranged so that the pen tip faces upward. FIG. 6 is a cross-sectional view showing an ink inhaler in a state where the central axis is inclined with respect to the vertical direction.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, the aspect ratio, and the like are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

In addition, as used in the present specification, the terms such as "parallel", "orthogonal", and "same" and the values of length and angle that specify the shape and geometric conditions and their degrees are strictly used. Without being bound by the meaning, we will interpret it including the range where similar functions can be expected.

1 to 6 are diagrams for explaining one embodiment according to the present invention. Of these, FIG. 1 is a view showing a cross section of a writing tool 10 in which an ink inhaler 20 is incorporated, FIG. 2 is an enlarged view showing an ink inhaler 20, and FIG. 3 is a view showing B- of FIG. It is a figure which shows the cross section corresponding to line B, and FIG. 4 is a cross-sectional view which shows the ink inhaler 20 in a state where the operating member 60 is pushed forward. In the present embodiment, an example in which the writing instrument 10 is a fountain pen will be described, but the writing instrument 10 is not limited to the fountain pen. In the present specification, the direction in which the central axis A of the main cylinder 30 of the ink inhaler 20 extends (longitudinal direction) is the axial direction, the direction orthogonal to the central axis A is the radial direction, and the circumferential direction around the central axis A is the circumferential direction. And. Further, in the writing instrument 10 and the ink inhaler 20, the side close to the writing surface such as the paper surface (for example, the lower side in FIG. 1) is the front side when writing along the axial direction, and the side away from the writing surface. (For example, the upper side in FIG. 1) is the rear side.

The writing instrument 10 shown in FIG. 1 includes a barrel 11, a pen tip 12, and a pen tip support portion 13 located in front of the barrel 11 and supporting the pen tip 12. The shaft cylinder 11 is a member having a longitudinal direction along the central axis A, and has a cavity that opens forward in the inside. In the present embodiment, at least a part of the ink inhaler 20 is housed in the cavity of the barrel 11. The pen tip 12 is a member that forms a handwriting on the writing surface by the ink supplied from the ink inhaler 20. The pen tip support portion 13 has an ink flow hole 14 and an air flow hole 15 inside. The ink flow hole 14 communicates with the pen tip 12 and functions as a passage for guiding the ink supplied from the ink inhaler 20 toward the pen tip 12. The air flow hole 15 extends substantially along the axial direction and opens in the vicinity of the pen tip 12. The air flow hole 15 functions as a passage for guiding the external air flowing in from the opening toward the ink inhaler 20. The pen tip support portion 13 is formed with a mounting portion 16 to which the ink inhaler 20 is mounted. In the present embodiment, the mounting portion 16 is configured as a protruding portion facing rearward, and the front end portion of the ink inhaler 20 is fitted onto the mounting portion 16 so that the ink inhaler 20 is attached to the pen tip support portion 13. It can be attached and detached. Not limited to this, the mounting portion 16 is configured as a groove portion that opens rearward, and the front end portion of the ink inhaler 20 is press-fitted into the mounting portion 16, so that the ink inhaler 20 is inserted into the pen tip support portion 13. It may be attached. A male screw portion is formed on the rear outer surface of the pen tip support portion 13, and a corresponding female screw portion is formed on the front inner surface of the barrel 11. Then, the female screw portion of the shaft cylinder 11 is screwed into the male screw portion of the pen tip support portion 13, so that the shaft cylinder 11 is attached to the pen tip support portion 13.

The ink inhaler 20 of the present embodiment is a push-type ink inhaler, and has an ink accommodating portion 21 for accommodating ink to be supplied to the pen tip 12 inside. The ink inhaler 20 includes a main cylinder 30 that defines an ink accommodating portion 21, a piston member 50 that is movably arranged with respect to the main cylinder 30, and a pipe that is movably held with respect to the piston member 50. It includes a 70 and a fixed piece member 80 fixed to the pipe 70. In the illustrated example, the ink inhaler 20 is attached to the tail cylinder 40 attached to the rear part of the main cylinder 30, the operating member 60 attached to the rear part of the piston member 50, and the pipe 70 behind the fixed piece member 80. It further has a movable piece member 90 that is loosely fitted. Hereinafter, each member constituting the ink inhaler 20 of the present embodiment will be described in order.

The main cylinder 30 is a member having a substantially cylindrical shape, and has an inner surface 30a and an outer surface 30b extending in the axial direction. The inner surface 30a has a reduced diameter portion 31 having a reduced inner diameter. The reduced diameter portion 31 is a protruding portion formed in an annular shape on the inner surface 30a along the circumferential direction. In particular, the reduced diameter portion 31 is a protruding portion whose inner surface 30a projects toward the central axis A. The ink accommodating portion 21 is formed behind the reduced diameter portion 31. Behind the apex of the reduced diameter portion 31 closest to the central axis A, a rear inclined surface 31a facing the ink accommodating portion 21 and inclined with respect to the axial direction and the radial direction is formed, and is anterior to the apex. Is formed with a forward inclined surface 31b inclined with respect to the axial direction and the radial direction. The rear inclined surface 31a is a surface extending outward in the radial direction toward the rear, and the front inclined surface 31b is a surface extending outward in the radial direction toward the front.

A tail cover 40 is attached to the rear part of the main cylinder 30. The tail covert 40 accommodates at least a part of the operating member 60. A collar portion 44 protruding inward is formed in the rear end opening 42 of the tail cover 40, and the collar portion 44 is in contact with a convex portion 64 described later of the operation member 60 in an open state of the operation member 60. Get in touch. The collar portion 44 may be one protruding portion provided over the entire circumference along the circumferential direction, or may be a plurality of protruding portions arranged discretely in the circumferential direction.

The piston member 50 has a flange portion 51 and a connecting convex portion 55 provided behind the flange portion 51. The flange portion 51 is located inside the main cylinder 30, and the outermost end portion of the flange portion 51 in the radial direction is in liquid-tight contact with the inner surface 30a of the main cylinder 30. As a result, the ink accommodating portion 21 is defined as a space surrounded by the inner surface 30a of the main cylinder 30, the reduced diameter portion 31, and the flange portion 51 of the piston member 50. The flange portion 51 has a recess 53 recessed rearward from the front end surface 51a. The connecting convex portion 55 functions as a connecting portion that connects the piston member 50 to the operating member 60. The connecting convex portion 55 is provided with a hole 57 that opens rearward. The piston member 50 has a partition wall 58 that closes the front of the hole 57, and a through hole 59 that connects the recess 53 and the hole 57 on the central axis A. A pipe 70 is loosely inserted into the through hole 59. That is, the inner diameter of the through hole 59 is larger than the outer diameter of the main body of the pipe 70, whereby the pipe 70 is held so as to be movable back and forth with respect to the piston member 50. The hole 57 serves as an introduction portion when the pipe 70 is inserted into the through hole 59, and defines a movable range when the pipe 70 moves back and forth with respect to the piston member 50.

The partition wall 58 has a plurality of grooves 59a communicating with the through hole 59 in order to ensure smooth flow of ink and air between the ink accommodating portion 21 and the hole 57, and the groove 59a has a plurality of grooves 59a. One is provided in the surface direction of the pen tip 12 shown in FIG. Four of the plurality of grooves 59a are arranged radially with respect to the through hole 59, and extend in the axial direction so as to communicate the recess 53 and the hole 57 in the same manner as the through hole 59. As a result, when writing with the surface of the pen tip 12 facing upward, the air in the ink accommodating portion 21 easily enters the hole 57 of the piston member 50 via the groove 59a, and the air in the hole 57 of the piston member 50 easily enters. The ink tends to flow out into the ink accommodating portion 21. The rear end portion 74 of the pipe 70 is formed with a diameter-expanded portion 76 in which the main body of the pipe 70 is expanded in the radial direction. The outer diameter D1 of the enlarged diameter portion 76 is larger than the inner diameter D2 of the through hole 59 of the piston member 50, but smaller than the maximum width L1 of the groove 59a (see FIG. 3). Therefore, even when the pipe 70 advances and the enlarged diameter portion 76 comes into contact with the partition wall 58, smooth flow of ink and air through the groove 59a can be ensured.

The operation member 60 is regulated to move back and forth with respect to the piston member 50, and is a member operated by the user when the piston member 50 is moved back and forth with respect to the main cylinder 30. The operating member 60 has a connecting recess 62 that opens to the front end surface and fits with the connecting convex portion 55 of the piston member 50. In the illustrated example, an engaging concave portion is provided on the side surface of the connecting concave portion 62, and an engaging convex portion corresponding to the engaging concave portion of the connecting concave portion 62 is provided on the side surface of the connecting convex portion 55. .. Then, the connecting convex portion 55 is inserted into the connecting concave portion 62, and the engaging convex portion of the connecting convex portion 55 and the engaging concave portion of the connecting concave portion 62 engage with each other, so that the piston member 50 engages with the operating member 60. Be connected. The connecting convex portion 55 of the piston member 50 is liquid-tightly attached to the connecting concave portion 62 so that the ink flowing into the hole 57 does not leak to the outside. A convex portion 64 that projects outward in the radial direction is provided on the outer peripheral surface of the operating member 60. An urging member 25 is arranged between the main cylinder 30 and the convex portion 64. In the illustrated example, the urging member 25 is a coil spring, which is inserted between the rear end portion of the main cylinder 30 and the front end portion of the convex portion 64 in a state of being compressed in the axial direction. As a result, the operating member 60 is urged rearward with respect to the main cylinder 30. The convex portion 64 comes into contact with the flange portion 44 of the tail cover 40 from the front in the open state of the operating member 60 (a state in which the operating member 60 is not pressed forward by the user). Therefore, the rear end of the movable range of the operating member 60 is defined by the flange portion 44.

The pipe 70 is arranged so as to extend in the main cylinder 30 through the reduced diameter portion 31. The front end 72 of the pipe 70 is located in front of the reduced diameter portion 31 in both the open state (see FIG. 2) and the pressing state (pressed forward by the user, see FIG. 4) of the operating member 60. .. Since the outer diameter D3 of the portion of the pipe 70 other than the enlarged diameter portion 76 shown in FIG. 3 is smaller than the inner diameter D2 of the through hole 59, the pipe 70 is front and rear in a state of being inserted through the through hole 59. It is movable in the direction and is located at the frontmost position with respect to the piston member 50 in a state where the enlarged diameter portion 76 is locked to the partition wall 58 from the rear. The inside of the pipe 70 is hollow, and the portion in front of the reduced diameter portion 31 of the main cylinder 30 and the hole 57 of the piston member 50 communicate with each other via the pipe 70.

The material for forming the pipe 70 is not particularly limited, but a metal material such as stainless steel can be used as an example. The material for forming the piston member 50 is not particularly limited, but as an example, a resin material such as polyethylene resin, polypropylene resin, or polyacetal resin can be used. Since the pipe 70 made of stainless steel has ink resistance and has better wettability to ink than resin materials such as polyethylene resin, polypropylene resin, and polyacetal resin forming the piston member 50, the air in the ink accommodating portion 21 can be removed. When entering the hole 57 of the piston member 50, the ink in the hole 57 of the piston member 50 flows out through the pipe 70 to the vicinity of the ink flow hole 14, and writing can be performed with the pen tip 12. Become. In this case, as shown in FIG. 2, in the axial direction from the rear end surface of the partition wall 58 of the piston member 50 to the rear end surface of the pipe 70 in a state where the pipe 70 is advanced and the enlarged diameter portion 76 is in contact with the partition wall 58. By setting the distance h1 to 0.5 mm or less, the ink in the hole 57 of the piston member 50 easily flows into the pipe 70, and the ink in the hole 57 of the piston member 50 smoothly flows out into the ink accommodating portion 21. It becomes possible to make it. When the central axis A of the ink inhaler 20 is inclined with respect to the vertical direction at the time of writing, the pipe member 70 is inclined with respect to the central axis A with the partition wall 58 of the piston member 50 as a fulcrum, and the piston member 50 The distance in the axial direction from the rear end surface of the partition wall 58 to the rear end surface of the pipe 70 changes, but as shown in FIG. 6, even the largest distance h2 is set to 0.5 mm or less. When the pipe 70 has better wettability to ink than the piston member 50, the ink in the hole 57 of the piston member 50 is not only discharged to the ink accommodating portion 21 through the pipe 70, but also the ink is discharged. It flows out into the ink accommodating portion 21 through the through hole 59 and the groove 59a of the piston member 50, along the outer surface of the pipe 70 having good wettability.

The fixed piece member 80 is fixed to the pipe 70 behind the reduced diameter portion 31. More specifically, the fixing piece member 80 is fixed to the outer surface of the pipe 70 behind the reduced diameter portion 31. The fixed piece member 80 is made of an elastic material. As this elastic material, fluororubber can be used as an example. The fixed piece member 80 has a closing surface 82 in front of the fixed piece member 80. In the illustrated example, the obstruction surface 82 includes an axially and radially inclined surface so as to be radially separated from the pipe 70 toward the rear. When the pipe 70 and the fixed piece member 80 move forward, the closing surface 82 abuts on the rear inclined surface 31a of the reduced diameter portion 31 to close the reduced diameter portion 31.

The movable piece member 90 is loosely fitted to the pipe 70 behind the fixed piece member 80. That is, the movable piece member 90 can move in the front-rear direction along the pipe 70 behind the fixed piece member 80. The movable piece member 90 is formed in a cylindrical shape as a whole, and a pipe 70 is inserted therein. The material for forming the movable piece member 90 is not particularly limited, but a metal material such as a stainless steel material can be used as an example.

In the ink inhaler 20 described above, in the open state shown in FIG. 2, the operating member 60 is urged rearward by the urging member 25. The convex portion 64 provided on the outer peripheral surface of the operating member 60 abuts from the front on the flange portion 44 provided on the rear end opening 42 of the tail cover 40, thereby restricting further movement of the operating member 60 to the rear. Has been done. At this time, the piston member 50 connected to the operating member 60, the pipe 70 held by the piston member 50, the fixed piece member 80 fixed to the pipe 70, and the movable piece member 90 loosely fitted to the pipe 70 are also rearward. positioned.

When sucking ink into the ink accommodating portion 21 of the ink inhaler 20, an ink bottle or the like in which the ink is stored is prepared, and the pen tip is attached to the pen tip support portion 13 with the ink inhaler 20 attached. The pen tip support portion 13 is immersed in the ink until the ink flow hole 14 and the air flow hole 15 are located below the liquid surface of the ink so that the ink 12 faces downward.

When the operating member 60 is pressed forward (downward) by, for example, a user's finger while the operating member 60 is facing upward, the pressing state shown in FIG. 4 is obtained. When shifting from the open state to the pressed state, the piston member 50, the pipe 70, the fixed piece member 80, and the movable piece member 90 also move forward as the operating member 60 moves forward. During this movement, first, the closing surface 82 of the fixed piece member 80 comes into contact with the rear inclined surface 31a of the reduced diameter portion 31 to close the reduced diameter portion 31. As a result, the pipe 70, the fixed piece member 80, and the movable piece member 90 are stopped. When the operating member 60 moves further forward, the piston member 50 moves further forward. At this time, the air compressed in the ink accommodating portion 21 passes through the gap between the through hole 59 of the piston member 50 and the pipe 70, passes through the hole 57 and the cavity in the pipe 70, and passes through the front end portion of the pipe 70. Outflow from 72. The air flowing out of the pipe 70 is discharged to the outside through the pen tip support portion 13. Since the through hole 59 of the piston member 50 has a plurality of grooves 59a communicating with the through hole 59, sufficient air flow between the ink accommodating portion 21 and the hole 57 is sufficiently ensured, and the ink is ink. Air can be quickly and stably moved from the inside of the accommodating portion 21 to the inside of the hole 57, and the smooth flow of ink from the inside of the hole 57 of the piston member 50 into the ink accommodating portion 21 can be ensured. it can.

In this state, for example, when the pressing force applied to the operating member 60 is released by releasing the finger of the user who has pressed the operating member 60 forward, the operating member is subjected to the urging force of the urging member 25. 60 retreats sharply. Along with this, the piston member 50 also suddenly retreats, and the pressure in the ink accommodating portion 21 becomes a negative pressure. When the operating member 60 and the piston member 50 are further retracted, the enlarged diameter portion 76 provided at the rear end portion 74 of the pipe 70 is locked in the through hole 59 of the piston member 50, and the pipe 70, the fixed piece member 80, and the movable piece are locked. The member 90 retracts together with the piston member 50. When the closing surface 82 of the fixed piece member 80 is separated from the rear inclined surface 31a of the reduced diameter portion 31, the pressure difference between the inside and the outside of the ink accommodating portion 21 causes the pen tip support portion 13 and the reduced diameter portion 31 to pass through. The ink in the ink bottle flows into the ink container 21.

By repeating this, the ink is sucked into the ink accommodating portion 21. If the operating member 60 is pressed forward while the ink is present in the ink accommodating portion 21, a small amount of ink may flow out from the ink accommodating portion 21 through the reduced diameter portion 31, but the fixed piece member After the diameter-reduced portion 31 is closed by 80, the ink does not flow out from the ink accommodating portion 21, and the air existing in the upper part of the ink accommodating portion 21 flows out through the pipe 70. After the ink is sucked into the ink inhaler 20, the shaft cylinder 11 is attached to the pen tip support portion 13, so that the writing instrument 10 is ready for writing.

FIG. 5 is a view showing a state in which the ink inhaler 20 is arranged so that the pen tip 12 faces upward. In this state, the pipe 70 moves rearward due to the action of gravity, and the rear end portion 74 is in contact with the lowermost portion (rearmost portion) of the connecting recess 62 of the operating member 60. The fixed piece member 80 is largely retracted with respect to the reduced diameter portion 31, and the reduced diameter portion 31 is in a communicating (non-blocking) state. The movable piece member 90 is located at the lowermost portion (rearmost portion) of the ink accommodating portion 21 and is in contact with the piston member 50. In the present embodiment, the outer diameter of the movable piece member 90 is smaller than the inner diameter of the recess 53 of the piston member 50. Therefore, the movable piece member 90 enters the recess 53 and comes into contact with the lowermost portion (rearmost portion) of the recess 53.

Writing using the writing instrument 10 is usually performed with the pen tip 12 facing downward and the longitudinal direction of the writing instrument 10 tilted with respect to the vertical direction (the direction in which gravity acts). At this time, the central axis A of the ink inhaler 20 is also inclined with respect to the vertical direction. FIG. 6 is a cross-sectional view showing the ink inhaler 20 in a state where the central axis A is inclined with respect to the vertical direction. In the process of transitioning the ink inhaler 20 from the state shown in FIG. 5 to the state shown in FIG. 6, the fixed piece member 80 moves forward by the action of gravity, whereby the ink in the ink accommodating portion 21 moves forward in the reduced diameter portion 31. Pushed towards.

In particular, when the amount of ink in the ink container 21 is reduced, even if the ink inhaler 20 is changed from the state shown in FIG. 5 to the state shown in FIG. 6, the ink is transferred to the rear part of the ink container 21 due to the action of surface tension. It may stay in the ink and not move forward. In the present embodiment, since the ink inhaler 20 has the movable piece member 90, the movable piece member 90 moves forward from the rearmost portion of the ink accommodating portion 21 to the rear portion of the ink accommodating portion 21. The retained ink is pushed forward. In particular, when the outer diameter of the movable piece member 90 is smaller than the inner diameter of the recess 53 of the piston member 50, the ink staying in the recess 53 is pushed forward as the movable piece member 90 moves forward. Is done.

In the writing state shown in FIG. 6, since the central axis A of the ink inhaler 20 is inclined with respect to the vertical direction, the fixed piece member 80 comes into contact with the inner surface 30a of the main cylinder 30 due to gravity. At the time of writing, ink is continuously supplied from the ink accommodating portion 21 to the pen tip 12 via the reduced diameter portion 31 and the ink flow hole 14. As the amount of ink in the ink containing portion 21 decreases, the pressure in the ink containing portion 21 becomes negative. Therefore, due to the pressure difference between the inside and the outside of the ink containing portion 21, the outside air flows into the ink containing portion 21 through the air flow hole 15 and the reduced diameter portion 31. At this time, the ink moves relatively downward toward the front, the air moves upward toward the rear, and when the ink is contained in the hole 57 of the piston member 50, the ink accommodating portion. The air in the 21 enters the hole 57 via the groove 59a of the piston member 50, and the ink in the hole 57 of the piston member 50 flows out into the ink accommodating portion 21.

10 Writing implements 11 Axial cylinder 12 Pen tip 13 Pen tip support part 20 Ink inhaler 21 Ink storage part 25 Biasing member 30 Main cylinder 30a Inner surface 30a1 Rear parallel part 30a2 Front parallel part 31 Reduced diameter part 31a Rear inclined surface 31b Forward inclined surface 32 Groove 35 Square 40 Tail 42 Rear end opening 44 Flange 50 Piston member 51 Flange 51a Front end surface 53 Recess 55 Connecting convex 57 Hole 58 Partition 59 Through hole 59a Groove 60 Operating member 62 Connecting recess 64 Convex 70 Pipe 72 Front end 74 Rear end 76 Diameter expansion 80 Fixed piece member 82 Closing surface 84 Rear end 86 Upper end edge 90 Movable piece member 92 Front end 94 Upper end edge

Claims (1)

A main cylinder having a reduced diameter portion on the inner surface and defining an ink accommodating portion behind the reduced diameter portion,
A piston member arranged so as to be movable back and forth with respect to the main cylinder,
A pipe that extends through the reduced diameter portion, extends inside the main cylinder, and is held so as to be movable back and forth with respect to the piston member.
A fixed piece member fixed to the pipe behind the reduced diameter portion is provided.
The piston member is provided with a hole through which the pipe retracts and a partition wall that closes the front of the hole.
An ink inhaler provided with a through hole through which the pipe is inserted and a plurality of grooves extending in the axial direction communicating with the through hole in the partition wall.

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