JP7118814B2 - ballpoint pen - Google Patents

Description

The present invention relates to ballpoint pens.

Japanese Unexamined Patent Application Publication No. 2002-100000 discloses a pen tip, an ink occluding body connected to the rear end of the pen tip, an ink tank disposed behind the ink occluding body and directly storing ink, and the ink tank. and a communicating tube connecting between the ink occluding body, the writing instrument comprising a plurality of the communicating tubes, each of the communicating tubes having an open front end and a front end of each of the communicating tubes A direct liquid writing instrument is disclosed, which is positioned in front of the inside of the ink occluding body, and in which the rear end of the pen tip is positioned in front of the inside of the ink occluding body. Further, in an embodiment (FIG. 4) of Patent Document 1, a ball-point pen is disclosed in which the rear end of the ink guide member is pierced and inserted through the front end of the ink occlusion body and positioned in front of the ink occlusion body.

Japanese Patent Application Laid-Open No. 2006-240281

In the ball-point pen described in Patent Document 1, there is a risk that the rear portion of the ink guide member protruding rearward from the ball-point pen tip may be bent when it is pierced and inserted into the ink occluding body. Further, in the ballpoint pen described in Patent Document 1, since the air hole is formed in the side wall of the tip member (corresponding to the front barrel of the present application), airtight fitting with the cap on the outer surface of the tip member (front barrel) Therefore, the position of the airtight fitting portion on the outer surface of the tip member (front shaft) cannot be freely set. Furthermore, in the ballpoint pen described in Patent Document 1, the appearance of the front end of the front barrel may be impaired by the air holes formed in the side wall of the tip member.

The present invention is intended to solve the above-mentioned conventional problems. To provide a ball-point pen in which the position of an airtight fitting portion on the outer surface of a front barrel can be freely set and the appearance of the front end of the front barrel is not spoiled.

In the present invention, "front" refers to the pen tip ball side, and "rear" refers to the opposite side.

A first invention of the present application is a ball-point pen tip 2 having a ball 21 rotatably held at its front end,
a rod-shaped ink guide member 3 that supplies ink to the ball 21 of the ballpoint pen tip 2;
an ink occluding body 4 connected to the rear end of the ink guide member 3;
an ink tank 5 disposed behind the ink occluding body 4 and directly storing ink;
A ball-point pen comprising a communicating pipe 6 having a flow passage 63 therein and connecting between the ink occluding body 4 and the ink tank 5,
a front shaft 8 having a front end to which the ballpoint pen tip 2 is fixed and a front end portion of the ink occluding body 4 to be accommodated;
A front end hole 81 is provided through the front end of the front shaft 8 in the axial direction,
A plurality of axially extending ribs 82 are integrally formed on the inner surface of the front end hole 81 at equal intervals in the circumferential direction. A stepped portion 82a is formed between the portion and the rear portion of the rib 82, and the stepped portion 82a and the rear end of the ball-point pen tip 2 are brought into contact with each other so that the rear portion of the rib 82 and the outer surface of the ink guide member 3 are in contact with each other. is in close proximity and
Between the ribs 82 between the outer surface of the ballpoint pen tip 2 and the inner surface of the front end hole 81, an air passage 9 is formed through which the inside of the front barrel 8 can communicate with the outside air. It is required that the front end of the front shaft 8 be opened forward.

In the ball-point pen 1 of the first invention, a front end hole 81 is provided axially through the front end of the front barrel 8, and a plurality of axially extending ribs 82 are formed on the inner surface of the front end hole 81 at regular intervals in the circumferential direction. The outer surface of the ball-point pen tip 2 is held in pressure contact with the front portion of the rib 82, and a stepped portion 82a is formed between the front portion of the rib 82 and the rear portion of the rib 82. The stepped portion 82a and the rear end of the ball-point pen tip 2 are brought into contact with the rear portion of the rib 82 and the outer surface of the ink guide member 3, and the outer surface of the ball-point pen tip 2 and the inner surface of the front end hole 81 are in contact with each other. An air passage 9 is formed between the ribs 82 so that the inside of the front barrel 8 can communicate with the outside air. The rear portion of the ink guide member 3 protruding rearward is not likely to be bent when it is pierced and inserted into the ink occluding member 4, and the position of the airtight fitting portion on the outer surface of the front shaft 8 can be freely set. Furthermore, the appearance of the front end of the front axle 8 is not spoiled.

A second invention of the present application is the ball-point pen of the first invention, wherein the diameter of an imaginary inscribed circle in contact with the apex of the rear portion of the rib 82 in the axial direction substantially coincides with the inner diameter of the rear end opening of the ball-point pen tip 2 . It is a requirement that

In the ball-point pen 1 of the second invention, the diameter of the imaginary inscribed circle contacting the apex of the rear portion of the rib 82 in the axial direction is approximately the same as the inner diameter of the rear end opening of the ball-point pen tip 2. The rear end of the ball-point pen tip 2 can be stably supported by 82 a (the front end of the rear portion of the rib 82 ), and the rear portion of the rib 82 can be brought as close to the outer surface of the ink guide member 3 as possible to pierce the ink occluding body 4 . It is possible to further prevent bending of the rear part of the ink guide member 3 when it is inserted.

A third invention of the present application is the ball-point pen according to the first or second invention, in which a cylindrical projecting portion 84 projecting rearward is integrally formed on the inner surface of the front end portion of the front barrel 8, and the front end of the front barrel 8 to the rear end of the cylindrical projection 84, and the rear end of the ballpoint pen tip 2 is positioned on the inner surface of the cylindrical projection 84. .

In the ball-point pen 1 of the third invention, a cylindrical projection 84 projecting rearward is integrally formed on the inner surface of the front end portion of the front barrel 8, and the rear end of the cylindrical projection 84 extends from the front end of the front barrel 8. The front end hole 81 is penetrated in the axial direction, and the rear end of the ball-point pen tip 2 is positioned on the inner surface of the cylindrical projecting portion 84, so that the outer surface of the ball-point pen tip 2 and the front portion of the rib 82 are connected to each other. A sufficiently long pressure contact area in the front-rear direction can be secured, and the outer surface of the ball-point pen tip 2 can be stably held.

A fourth invention of the present application is a ball-point pen according to the first, second or third invention, wherein the thickness V of the rib 82 is increased toward the rear.

In the ball-point pen 1 of the fourth aspect of the invention, the thickness V of the rib 82 is increased toward the rear, so that the front portion of the rib 82 is relatively thin. Even if the amount of protrusion is small, a sufficient air passage 9 can be stably secured between the front portion of the rib 82 and the outer surface of the ballpoint pen tip 2, and the rear portion of the rib 82 is relatively thick. The rear portion of the rib 82 can stably support the outer surface of the ink guide member 3 when it is pierced and inserted into the ink occluding member 4, thereby further preventing the ink guide member 3 from bending.

A fifth invention of the present application is a ball-point pen tip 2 having a ball 21 rotatably held at its front end,
a rod-shaped ink guide member 3 that supplies ink to the ball 21 of the ballpoint pen tip 2;
A ballpoint pen comprising an ink occluding body 4 connected to the rear end of the ink guide member 3,
a front shaft 8 having a front end to which the ballpoint pen tip 2 is fixed and a front end portion of the ink occluding body 4 to be accommodated;
A front end hole 81 is provided through the front end of the front shaft 8 in the axial direction,
A plurality of axially extending ribs 82 are integrally formed on the inner surface of the front end hole 81 at equal intervals in the circumferential direction. A stepped portion 82a is formed between the portion and the rear portion of the rib 82, the stepped portion 82a and the rear end of the ball-point pen tip 2 are in contact with each other, and the rear portion of the rib 82 and the outer surface of the ink guide member 3 are in contact with each other. is in close proximity,
Between the ribs 82 between the outer surface of the ballpoint pen tip 2 and the inner surface of the front end hole 81, an air passage 9 is formed through which the inside of the front barrel 8 can communicate with the outside air. It is required that the front end of the front shaft 8 be opened forward.

In the ballpoint pen 1 of the fifth invention, a front end hole 81 is provided axially through the front end of the front barrel 8,
A plurality of axially extending ribs 82 are integrally formed on the inner surface of the front end hole 81 at equal intervals in the circumferential direction. A stepped portion 82a is formed between the portion and the rear portion of the rib 82, the stepped portion 82a and the rear end of the ball-point pen tip 2 are in contact with each other, and the rear portion of the rib 82 and the outer surface of the ink guide member 3 are in contact with each other. Between the ribs 82 which are close to each other and between the outer surface of the ball-point pen tip 2 and the inner surface of the front end hole 81, an air passage 9 is formed through which the inside of the front barrel 8 can communicate with the outside air. Since the passage 9 is opened forward from the front end of the front barrel 8, there is no possibility that the rear portion of the ink guide member 3 projecting rearward from the ballpoint pen tip 2 will be bent when it is pierced and inserted into the ink occluding member 4. Further, the position of the airtight fitting portion on the outer surface of the front shaft 8 can be freely set, and the appearance of the front end portion of the front shaft 8 is not spoiled.

In the ball-point pen of the present invention, the rear portion of the ink guide member protruding rearward from the ball-point pen tip is not likely to bend when it is pierced and inserted into the ink occluding body, and the position of the airtight fitting portion on the outer surface of the front barrel is adjusted. It can be set freely, and the appearance of the front end of the front axle is not spoiled.

1 is a longitudinal sectional view of a ballpoint pen according to an embodiment of the invention; FIG. FIG. 2 is an enlarged vertical cross-sectional view of a main portion of FIG. 1; FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2; FIG. 3 is a cross-sectional view taken along line BB of FIG. 2; 3 is a cross-sectional view taken along line CC of FIG. 2; FIG. FIG. 2 is a perspective view of a main part of FIG. 1; 2 is an enlarged vertical cross-sectional view of the ball-point pen tip portion of FIG. 1; FIG. FIG. 8 is a cross-sectional view taken along line DD of FIG. 7; FIG. 8 is a cross-sectional view taken along line EE of FIG. 7; FIG. 8 is a cross-sectional view taken along line FF of FIG. 7; FIG. 8 is a cross-sectional view taken along line GG of FIG. 7; It is a longitudinal cross-sectional view of a ball-point pen of another embodiment of the present invention.

A ballpoint pen according to an embodiment of the present invention is shown in FIGS. 1 to 11. FIG.
As shown in FIG. 1, the ball-point pen 1 of the present embodiment includes a ball-point pen tip 2, a rod-shaped ink guide member 3 for supplying ink to a ball 21 of the ball-point pen tip 2, and a rear end of the ink guide member 3 connected to the ink guide member 3. an intermediate member 7 arranged behind the ink occluding member 4; a rear shaft serving as an ink tank 5 arranged behind the intermediate member 7; It consists of a front barrel 8 in which the ball-point pen tip 2 is held in the part thereof, and a cap (not shown) detachably provided on the ball-point pen tip 2 side. The ink occluding body 4 and the intermediate member 7 are housed inside the front shaft 8 . In this embodiment, the entire ink occluding body 4 is housed inside the front shaft 8. Alternatively, only the front end portion of the ink occluding body 4 may be housed inside the front shaft 8. A configuration in which only the front portion of the ink occluding body 4 is accommodated may be employed.

Ball-point pen tip The ball-point pen tip 2 consists of a tip body 22 and a ball 21 rotatably held at the front end of the tip body 22 . A front end portion of the tip body 22 is tapered. The tip body 22 is made of metal (eg stainless steel) or synthetic resin (eg polyacetal resin). When the tip body 22 is made of a metal material, the ball receiving seat of the ball holding portion at the front end portion of the tip body 22 that holds the ball 21 is obtained by cutting or plastic working. The leading edge is obtained by plastic working. When the tip body 22 is made of synthetic resin, the ball holding portion at the front end of the tip body 22 that holds the ball 21 is obtained by injection molding. The ballpoint pen tip 2 is press-fitted and fixed to the front end hole 81 of the front barrel 8 . The ball 21 of the ball-point pen tip 2 has a diameter in the range of 0.3 mm to 1.0 mm.

Ink Guide Member The ink guide member 3 is a rod-shaped body obtained by processing synthetic resin fibers (eg, polyester fiber, acrylic fiber, nylon fiber, etc.) with resin. As shown in FIG. 2, the front end of the ink guide member 3 is tapered and inserted from behind the ball-point pen tip 2 . The front end of the ink guide member 3 is arranged in the ink lead-out hole at the axis of the ball receiving seat that contacts the back surface of the ball 21 . The rear end of the ink guide member 3 protrudes rearward from the rear end of the tip body 22 . A rear end face 31 of the ink guide member 3 is formed in a planar shape perpendicular to the axis.

As shown in FIG. 7, the side wall of the tip body 22 is formed with a plurality of (specifically, four) inward protrusions 22a that protrude inward in the radial direction. . The inward protrusion 22a is pressed against the outer surface of the ink guide member 3. As shown in FIG. As a result, the outer surface of the ink guide member 3 is securely held on the inner surface of the side wall of the tip body 22, preventing the ink guide member 3 from rattling in the ballpoint pen tip 2 in the front-rear direction. 21 to obtain a stable ink connection state.
In this embodiment, the outer diameter S of the rear end of the ink guide member 3 is set to 1.5 mm. In the present embodiment, the ink guide member 3 is pierced into the ink occluding body 4 for a length of 23 mm behind the front end of the ink occluding body 4 in the axial direction.

Ink occluding body The ink occluding body 4 is made of a cylindrically processed synthetic resin fiber bundle (for example, polyester fiber bundle). The outer peripheral surface of the ink occluding body 4 is covered with a synthetic resin cylindrical outer skin. The rear end of the ink guide member 3 is pierced and inserted into the axial center of the front end face 61 of the ink occlusion body 4 , and the rear end of the ink guide member 3 is positioned inside the ink occlusion body 4 near the rear end. In this embodiment, the ink occluding body 4 has an outer diameter of 7 mm and an axial length of 30 mm.

- Intermediate member The intermediate member 7 is obtained by injection molding of a synthetic resin (eg, polypropylene, polyethylene, etc.). As shown in FIG. 2, the intermediate member 7 includes a partition wall 71 that separates the ink occluding body 4 and the ink tank 5 from each other, and a plurality of intermediate members that protrude forward from the front surface of the partition wall 71 and are connected to the inside of the ink occluding body 4 by piercing. two (specifically, two) communicating pipes 6; a cylindrical mounting portion 72 projecting rearward from the rear surface of a partition wall 71 and fitted to the inner surface of the front shaft 8; and a connection pipe 73 fitted to the front end opening of the ink tank 5 . The outer diameter of the cylindrical attachment portion 72 is set larger than the outer diameter of the connecting pipe 73 . A space formed by the front shaft 8 and the partition wall 71 (i.e., the ink occluding member accommodating portion) accommodates the ink occluding member 4 .

In the present embodiment, the partition wall 71 is disk-shaped, and the cylindrical attachment portion 72 and the connecting pipe 73 are cylindrical.

The partition wall 71, each communicating pipe 6, the connecting pipe 73, and the tubular mounting portion 72 are integrally connected. That is, the partition wall 71, the communicating pipe 6, the connecting pipe 73, and the cylindrical mounting portion 72 can be configured as one component by the intermediate member 7. As shown in FIG.

Communicating Pipe A flow passage 63 is provided in the axial direction inside each of the communicating pipes 6 , and the flow passages 63 are opened at both ends of each of the communicating pipes 6 . A front end of each communicating pipe 6 is opened inside the ink occluding body 4 , and a rear end of each communicating pipe 6 is opened inside the ink tank 5 via a connecting pipe 73 . Since each communication pipe 6 is arranged in parallel between the ink occluding body 4 and the ink tank 5, a plurality of independent flow paths are formed between the ink occluding body 4 and the ink tank 5 behind it. 63 are provided in parallel. The flow passage 63 of each of the communication pipes 6 penetrates the partition wall 71 located inside the cylindrical mounting portion 72 and the connection pipe 73 at a location away from the axis. In addition to this, the flow path 63 of the communication pipe 6 is formed by a single flow path 63 to the vicinity of the plurality of openings 62 at the front end of each communication pipe 6, and each of the single flow paths 63 A configuration in which the opening 62 of is communicated with is also possible.

- The side walls of the communicating pipes 6 of the connecting portions are integrally connected by the connecting portions 64 . The front end of the connecting portion 64 is aligned with the front end of each communicating pipe 6 in the longitudinal direction. A front end surface 61 of each communicating tube 6 is formed in a continuous plane perpendicular to the axis, and has an opening 62 of each communicating tube 6 . A front end surface 61 of each communicating pipe 6 has a flat elliptical outer shape. At the center of the central region 61a (connecting portion 64) of the front end face 61 of the communicating pipe 6, the width dimension T (width dimension of the connecting portion 64) perpendicular to the imaginary straight line connecting the openings 62 is 2 8 mm, which is larger than the outer diameter S (1.5 mm) of the rear end face 31 of the ink guide member 3 . The opening 62 of the front end face 61 of each communicating pipe 6 is arranged at a position spaced radially outward from the axial center of the ink occluding body 4 . More specifically, the openings 62 of the front end face 61 of each communicating pipe 6 are arranged on the same circumference around the axial center of the ink occluding body 4 at regular intervals. In this embodiment, since there are two communication pipes 6, the communication pipes 6 are arranged 180 degrees symmetrical with respect to the axis of the ink occluding body 4. As shown in FIG.

Ribs on the Inner Surface of Flow Path As shown in FIG. 4, ribs 63a projecting radially inward and extending in the axial direction are integrally formed on the inner surface of the flow path 63 inside each communicating pipe 6. As shown in FIG. A plurality of ribs 63a (specifically, two ribs) are provided on the inner surface of the flow passage 63 inside each communicating pipe 6, but one rib may also be provided. Moreover, although the ribs 63a are formed only on one side of the inner surface of the flow path 63 of each communicating pipe 6, a plurality of ribs 63a may be formed around the entire circumference of each flow path 63 at equal intervals. Due to the ribs 63a, the ink can be supplied more quickly from the openings 62 of the front end surface 61 of the communicating pipe 6 to the rear end surface 31 of the ink guide member 3 via the high density portion 41, Smooth intake of air becomes possible when the internal pressure drops. The inner diameter of each flow passage 63 of the communication pipe 6 (the inner diameter of the portion excluding the rib 63a) is set to 1.4 mm.

2, 5, and 6, a plurality of (specifically, four) ribs 71a extending in the axial direction are formed on the front surface of the partition wall 71 and on the rear outer surface of the communicating pipe 6. They are formed at regular intervals in the circumferential direction. The rear end surface of the ink occluding member 4 is brought into contact with the front end of the rib 71a. A communicating pipe 6 protruding forward from the front end of the rib 71a is inserted into the ink occluding body 4 from the rear end surface of the ink occluding body 4. As shown in FIG.

- The front end face 61 of each communicating tube 6 in the high-density portion is formed into a single continuous plane that includes the front end face 61 of the connecting portion 64 and is perpendicular to the axis. A rear end face 31 of the ink guide member 3 is formed in a planar shape perpendicular to the axis. The front end of each communicating pipe 6 is inserted into the ink occluding body 4 forward of the rear end face of the ink occluding body 4 . A front end face 61 of each communicating pipe 6 is positioned forward of a rear end face of the ink occluding body 4 . The axial length from the front end face 61 of each communicating pipe 6 to the rear end face of the ink occluding member 4 is set within a range of 2 mm to 8 mm. A central region 61a between the openings 62 of the front end face 61 of each communicating tube 6 is located axially rearward of the rear end face 31 of the ink guide member 3. As shown in FIG. The vicinity of the rear end of the ink occluding member 4 is axially sandwiched and compressed between the central region 61a between the openings 62 of the front end faces 61 of the communicating pipes 6 and the rear end face 31 of the ink guide member 3. . As a result, a high-density portion is formed in the vicinity of the rear end of the ink occluding member 4 between the central region 61a between the openings 62 of the front end surfaces 61 of the communicating pipes 6 and the rear end surface 31 of the ink guide member 3. 41 is formed.

In the high-density portion 41, the fiber density of the ink occluding body 4 is set higher than the fiber density of the ink occluding body 4 in other portions. That is, a high-density portion 41 having a high fiber density (a high-density portion 41 having a large capillary force) is formed in the vicinity of the rear end portion inside the ink occluding body 4, and the high-density portion 41 inside the ink occluding body 4 is formed in front of the high density portion 41. A low-density portion 42 having a low fiber density (a low-density portion 42 having a low capillary force) is formed. As a result, the high-density portion 41 can be impregnated preferentially with the ink inside the ink occluding member 4 rather than the low-density portion 42, and the opening 62 of the front end surface 61 of each communicating pipe 6 can be filled with the impregnated ink. Liquid sealing can be reliably performed, and excessive leakage of ink from the ink tank 5 from the ball-point pen tip 2 side can be prevented.

The rear end surface 31 of the ink guide member 3 is located at a distance of 65% to 90% (preferably 70% to 85%) of the length of the ink occluding body 4 from the front end of the ink occluding body 4 . It is useful to have The front end surface 61 of each communicating pipe 6 is separated from the rear end of the ink occluding body 4 by a length of 5% to 25% (preferably 10% to 20%) of the total length of the ink occluding body 4 in the longitudinal direction. It is valid to be in position. In this embodiment, the rear end surface 31 of the ink guide member 3 is positioned 23 mm from the front end of the ink occluding body 4 . A front end surface 61 of each communicating pipe 6 is positioned 4 mm from the rear end of the ink occluding body 4 . A high-density portion 41 is formed in a region of 3 mm in axial length inside the ink occluding member 4 between the rear end face 31 of the ink guide member 3 and the front end face 61 of each communicating tube 6 .

* Front shaft The front shaft 8 is a cylindrical body obtained by injection molding of synthetic resin (eg, polypropylene, polyethylene, etc.). The front barrel 8 has a tapered portion having a front end hole 81 into which the outer peripheral surface of the rear portion of the ballpoint pen tip 2 is press-fitted and fixed, and a body portion connected to the rear of the tapered portion and containing the ink occluding body 4 and the intermediate member 7. Consists of The outer surface of the rear end opening of the front shaft 8 (main body) and the front end opening of the rear shaft (ink tank 5) are press-fitted and fixed. The front end hole 81 is provided axially through the front end of the front shaft 8 .

A plurality of (specifically, four) ribs 82 protruding radially inward and extending in the axial direction are integrally formed on the inner surface of the front end hole 81 of the front rib shaft 8 at equal intervals in the circumferential direction. The rear portion of the ballpoint pen tip 2 is press-fitted into the front end hole 81 having the rib 82 . The outer surface of the ball-point pen tip 2 is radially press-contacted and held at the front portion of the rib 82 . The rear portion of the rib 82 and the outer surface of the ink guide member 3 are radially adjacent to each other, and the ink guide member 3 is loosely inserted into the rear portion of the rib 82 . A stepped portion 82a is formed between the front portion and the rear portion of the rib 82, and the rear end of the ball-point pen tip 2 abuts against the stepped portion 82a in the axial direction.

An air passage 9 is formed between the ribs 82 between the inner surface of the front end hole 81 and the outer surface of the ballpoint pen tip 2 . Outside air is taken into the ink tank 5 through the air passage 9 . An air passage 9 opens forward from the front end of the front shaft 8 . In the present embodiment, the radial gap dimension of the air passage 9 formed between the front portion of the rib 82 and the outer surface of the ballpoint pen tip 2 decreases toward the rear, and is 0.15 mm at the front end and 0.15 mm at the rear end. It is set to 0.09 mm. Also, the gap dimension between the rear portion of the rib 82 and the outer surface of the ink guide member 3 is set at a substantially constant 0.05 mm along the axial direction.

The diameter of the imaginary inscribed circle contacting the top of the rear portion of the rib 82 in the axial direction is substantially the same as the inner diameter of the rear end opening of the ball-point pen tip 2 . Also, the thickness V of the rib 82 increases toward the rear. In this embodiment, the diameter of the imaginary inscribed circle contacting the top of the rear portion of the rib 82 in the axial direction and the inner diameter of the rear end opening of the ball-point pen tip 2 are specifically set to 1.6 mm.

A tubular projecting portion 84 having a front end hole 81 therein and projecting rearward is integrally formed on the inner surface of the front end portion of the front shaft 8 . A front end hole 81 axially penetrates from the front end of the front shaft 8 to the rear end of the tubular projecting portion 84 . A rib 82 and a step portion 82a are formed on the inner surface of the tubular projecting portion 84 . The rear end of the ball-point pen tip 2 is brought into contact with the stepped portion 82a, and the rear end of the ball-point pen tip 2 is positioned on the inner surface of the tubular projecting portion 84. As shown in FIG.

A plurality of (specifically, six) ribs 83 protruding radially inward and extending in the axial direction are integrally formed on the inner surface behind the front end of the front shaft 8 at equal intervals in the circumferential direction. A stepped portion 83a is provided at the front portion of the rib 83, and the front end face of the ink occluding body 4 is axially abutted against the stepped portion 83a. The outer surface of the ink occluding body 4 is radially press-contacted and held by the rib 83 behind the stepped portion 83a.

・Ink tank (rear shaft)
The ink tank 5 is a bottomed cylindrical body with an open front end and a closed rear end. The ink tank 5 is obtained by injection molding of synthetic resin. Ink is directly stored in the ink tank 5. - 特許庁The ink stored in the ink tank 5 may be either water-based ink or oil-based ink. The ink tank 5 can be configured to be detachable and replaceable.

As shown in FIGS. 1 and 2, at the front end of the ink tank 5, an inner cylindrical portion 51 and an outer cylindrical portion 52 are integrally formed concentrically. The inner cylinder portion 51 is connected to the connection pipe 73 of the intermediate member 7 , and the outer cylinder portion 52 is connected to the rear end portion of the front shaft 8 . In the present embodiment, a structure is employed in which the outer surface of the connecting pipe 73 and the inner surface of the front end portion of the ink tank 5 are press-fitted and fixed. may be press-fitted and fixed. In the present embodiment, a structure is employed in which the outer surface of the rear end of the front shaft 8 and the inner surface of the outer cylindrical portion 52 of the ink tank 5 are fitted together. and the outer surface of the outer cylindrical portion 52 of the ink tank 5 may be fitted together.

The ball-point pen 1 of the present embodiment includes a plurality of openings 62 communicating with the flow passage 63 at the front end of the communicating tube 6 and opening axially forward. The ink guide member 3 penetrates through the interior of the low density portion 42, and the rear end of the ink guide member 3 and the communication pipe 6 are connected to the high density portion 41. Since the density of the high-density portion 41 is prevented from becoming excessively high by connecting the front end to the front end, sufficient ink ejection performance from the front end of the ball-point pen tip 2 can be obtained, and the low-density portion 42 can be made high. By locating it forward of the density portion 41, it is possible to sufficiently prevent ink from leaking outside from the ball-point pen tip side when the pressure in the ink tank 5 rises.

In the ball-point pen 1 of this embodiment, the rear end of the ink guide member 3 is positioned at the rear of the ink occluding body 4, the front end of the communicating tube 6 is positioned at the rear of the ink occluding body 4, and the rear end of the ink guide member 3 is The front end of the communication pipe 6 is positioned further rearward, and the high density portion 41 is formed between the rear end of the ink guide member 3 and the front end of the communication pipe 6 (or the high density portion 41 is formed between the ink occluding body 4 The low-density portion 42 has a sufficient longitudinal length in front of the high-density portion 41 without excessively increasing the density of the high-density portion 41 by being formed in the vicinity of the rear end portion of the high-density portion 42. can be ensured, a sufficient ink ejection property can be obtained from the front end of the ball-point pen tip 2, and when the pressure in the ink tank 5 rises, the leakage of ink from the ball-point pen tip side to the outside can be sufficiently prevented. can. The axial length from the rear end of the ink occluding body 4 to the front end surface 61 of each communicating pipe 6 is set smaller than the outer diameter of the ink occluding body 4 . As a result, sufficient ink ejection from the front end of the ball-point pen tip 2 can be obtained, and leakage of ink from the ball-point pen tip side to the outside when the pressure inside the ink tank 5 rises can be sufficiently prevented. An appropriate high density portion 41 can be formed.

In the ballpoint pen 1 of the present embodiment, the communicating tube 6 has one continuous front end surface 61 having a plurality of openings 62, and the front end surface 61 of the communicating tube 6 is formed in a plane perpendicular to the axis, A rear end face 31 of the ink guide member 3 is formed in a plane shape perpendicular to the axis, and a central region 61 a located between a plurality of openings 62 of the front end face 61 of the communicating pipe 6 is formed on the ink guide member 3 . The vicinity of the rear end portion of the ink occluding member 4 is axially sandwiched and compressed by the central region 61 a of the front end surface 61 of the communicating pipe 6 and the rear end surface 31 of the ink guide member 3 . The high-density portion 41 is formed in the vicinity of the rear end portion of the ink occluding member 4 between the central region 61 a of the front end surface 61 and the rear end surface 31 of the ink guide member 3 , so that the rear end surface 31 of the ink guide member 3 is The high-density portion 41 to be connected can be reliably formed.

In the ballpoint pen 1 of the present embodiment, the width dimension T in the direction perpendicular to the imaginary straight line connecting the openings 62 at the center of the central region 61a of the front end face 61 of the communicating tube 6 is Since the rear end surface 31 of the rear end surface 31 is larger than the outer diameter S, the rear end surface 31 of the ink guide member 3 can be reliably connected to the high density portion 41 , and the rear end surface 31 of the ink guide member 3 can be connected from the opening 62 of the communicating pipe 6 to the ink guide member 3 . Ink can be supplied quickly and reliably to the

In the ball-point pen 1 of the present embodiment, the outer shape of the front end surface 61 of the communicating tube 6 is a flat elliptical shape. can be more reliably connected to the high-density portion 41 .

In the ballpoint pen 1 of the present embodiment, a front end hole 81 is provided axially through the front end of the front barrel 8, and a plurality of axially extending ribs 82 are integrally formed on the inner surface of the front end hole 81 at regular intervals in the circumferential direction. The outer surface of the ballpoint pen tip 2 is pressed against and held by the front portion of the rib 82, the stepped portion 82a is formed between the front portion of the rib 82 and the rear portion of the rib 82, and the stepped portion 82a and the rear end of the ballpoint pen tip 2 are formed. , the rear portion of the rib 82 and the outer surface of the ink guide member 3 are brought close to each other, and the inside of the front barrel 8 and the inner surface of the front barrel 8 are formed between the ribs 82 between the outer surface of the ballpoint pen tip 2 and the inner surface of the front end hole 81 . An air passage 9 communicating with the outside air is formed, and the air passage 9 opens forward from the front end of the front barrel 8, so that the rear portion of the ink guide member 3 projecting rearward from the ball-point pen tip 2 absorbs ink. There is no risk of bending when it is pierced and inserted into the body 4, the position of the airtight fitting portion on the outer surface of the front barrel 8 can be freely set, and the appearance of the front end portion of the front barrel 8 is spoiled. never be

In the ball-point pen 1 of the present embodiment, the diameter of the imaginary inscribed circle contacting the apex of the rear portion of the rib 82 in the axial direction is approximately the same as the inner diameter of the rear end opening of the ball-point pen tip 2, so that the stepped portion 82a ( The rear end of the ball-point pen tip 2 can be stably supported by the front end of the rear portion of the rib 82 , and the rear portion of the rib 82 can be brought as close to the outer surface of the ink guide member 3 as possible so that the ink occluding member 4 can be pierced and inserted. It is possible to further prevent bending of the rear part of the ink guide member 3 when the ink guide member 3 is drawn.

In the ballpoint pen 1 of the present embodiment, a cylindrical projecting portion 84 projecting rearward is integrally formed on the inner surface of the front end portion of the front barrel 8 , and a space between the front end of the front barrel 8 and the rear end of the cylindrical projecting portion 84 is formed. The front end hole 81 is penetrated in the axial direction, and the rear end of the ballpoint pen tip 2 is positioned on the inner surface of the cylindrical projection 84, so that the outer surface of the ballpoint pen tip 2 and the front portion of the rib 82 have a sufficient length in the front-rear direction. It is possible to secure a pressure contact area of a thickness and to stably hold the outer surface of the ball-point pen tip 2. - 特許庁

In the ball-point pen 1 of the present embodiment, the thickness V of the rib 82 is increased toward the rear, so that the front portion of the rib 82 is relatively thin. Even if the diameter of the rib 82 is reduced, a sufficient air passage 9 can be stably secured between the front portion of the rib 82 and the outer surface of the ballpoint pen tip 2, and the rear portion of the rib 82 is relatively thick, so that ink can be absorbed. The rear part of the rib 82 can stably support the outer surface of the ink guide member 3 when it is pierced and inserted into the body 4, and the bending of the ink guide member 3 can be further prevented.

<Other embodiments>
A ballpoint pen according to another embodiment of the present invention is shown in FIGS. 7-12.
As shown in FIG. 12, the ball-point pen 1 of the present embodiment has a ball-point pen tip 2, a rod-shaped ink guide member 3 that supplies ink to the ball of the ball-point pen tip 2, and the rear end of the ink guide member 3. An ink occluding body 4, a front barrel 8 (barrel) in which the ink guide member 3 and the ink occluding body 4 are accommodated and a ballpoint pen tip 2 is held at the front end thereof, and a rear end opening of the front barrel 8. and a cap (not shown) detachably provided on the ballpoint pen tip 2 side.

The ball-point pen tip 2 and the ink guide member 3 of this embodiment employ the same configuration as that of the embodiment of FIG.
The ink occluding body 4 of this embodiment has a longer longitudinal dimension than that of the embodiment shown in FIG. 1, and other constructions are common to those of the embodiment shown in FIG.
The structure of the front end portion of the front shaft 8 of this embodiment is the same as that of the front shaft 8 of the embodiment shown in FIG. 7 to 11) is adopted.

In the ballpoint pen 1 of the present embodiment, a front end hole 81 is provided axially through the front end of the front barrel 8, and a plurality of axially extending ribs 82 are integrally formed on the inner surface of the front end hole 81 at regular intervals in the circumferential direction. The outer surface of the ballpoint pen tip 2 is pressed against and held by the front portion of the rib 82, the stepped portion 82a is formed between the front portion of the rib 82 and the rear portion of the rib 82, and the stepped portion 82a and the rear end of the ballpoint pen tip 2 are formed. , the rear portion of the rib 82 and the outer surface of the ink guide member 3 are brought close to each other, and the inside of the front barrel 8 and the inner surface of the front barrel 8 are formed between the ribs 82 between the outer surface of the ballpoint pen tip 2 and the inner surface of the front end hole 81 . An air passage 9 communicating with the outside air is formed, and the air passage 9 opens forward from the front end of the front barrel 8, so that the rear portion of the ink guide member 3 projecting rearward from the ball-point pen tip 2 absorbs ink. There is no risk of bending when it is pierced and inserted into the body 4, the position of the airtight fitting portion on the outer surface of the front barrel 8 can be freely set, and the appearance of the front end portion of the front barrel 8 is spoiled. never be

In the ball-point pen 1 of the present embodiment, the diameter of the imaginary inscribed circle contacting the apex of the rear portion of the rib 82 in the axial direction is approximately the same as the inner diameter of the rear end opening of the ball-point pen tip 2, so that the stepped portion 82a ( The rear end of the ball-point pen tip 2 can be stably supported by the front end of the rear portion of the rib 82 , and the rear portion of the rib 82 can be brought as close to the outer surface of the ink guide member 3 as possible so that the ink occluding member 4 can be pierced and inserted. It is possible to further prevent bending of the rear part of the ink guide member 3 when the ink guide member 3 is drawn.

In the ballpoint pen 1 of the present embodiment, a cylindrical projecting portion 84 projecting rearward is integrally formed on the inner surface of the front end portion of the front barrel 8 , and a space between the front end of the front barrel 8 and the rear end of the cylindrical projecting portion 84 is formed. The front end hole 81 is penetrated in the axial direction, and the rear end of the ballpoint pen tip 2 is positioned on the inner surface of the cylindrical projection 84, so that the outer surface of the ballpoint pen tip 2 and the front portion of the rib 82 have a sufficient length in the front-rear direction. It is possible to secure a pressure contact area of a thickness and to stably hold the outer surface of the ball-point pen tip 2. - 特許庁

In the ball-point pen 1 of the present embodiment, the thickness V of the rib 82 is increased toward the rear, so that the front portion of the rib 82 is relatively thin. Even if the diameter of the rib 82 is reduced, a sufficient air passage 9 can be stably secured between the front portion of the rib 82 and the outer surface of the ballpoint pen tip 2, and the rear portion of the rib 82 is relatively thick, so that ink can be absorbed. The rear part of the rib 82 can stably support the outer surface of the ink guide member 3 when it is pierced and inserted into the body 4, and the bending of the ink guide member 3 can be further prevented.

1 ballpoint pen 2 ballpoint pen tip 21 ball 22 tip body 22a inward projection 3 ink guide member 31 rear end face 4 ink occlusion body 41 high density portion 42 low density portion 5 ink tank (rear barrel)
51 inner cylindrical portion 52 outer cylindrical portion 6 communicating pipe 61 front end face 61a central region 62 opening 63 flow passage 63a rib 64 connecting portion 7 intermediate member 71 partition wall 71a rib 72 on the front surface of partition wall cylindrical mounting portion 73 connecting pipe 8 front shaft 81 Front end hole 82 Rib 82a Stepped portion 83 Rib 83a Stepped portion 84 Cylindrical projecting portion 9 Air passage 10 Tail plug S Outer diameter T of the rear end of the ink guide member Width dimension U of the central region of the front end face of the communicating pipe Gap dimension V Rib thickness of

Claims (4)

A ball-point pen tip having a ball rotatably held at its front end, a rod-shaped ink guide member for supplying ink to the ball of the ball-point pen tip, an ink occluding body connected to the rear end of the ink guide member, and the ink. A ball-point pen comprising: an ink tank arranged behind an occluding body and directly storing ink; and a communicating pipe having a flow path therein and connecting between the ink occluding body and the ink tank, A front shaft having a front end to which the ball-point pen tip is fixed and a front end portion of the ink occluding body is accommodated therein is provided. A plurality of ribs extending in the direction are integrally formed at equal intervals in the circumferential direction, the outer surface of the ball-point pen tip is held in pressure contact with the front portion of the rib, and a step is formed between the front portion of the rib and the rear portion of the rib. a portion is formed, the stepped portion and the rear end of the ball-point pen tip are brought into contact with each other, the rear portion of the rib and the outer surface of the ink guide member are brought close to each other, and the outer surface of the ball-point pen tip and the inner surface of the front end hole are in contact with each other. An air passage is formed between the ribs between the ribs so that the inside of the front shaft can communicate with the outside air. The front end hole is axially penetrated from the front end of the front barrel to the rear end of the cylindrical protrusion, and the rear end of the ballpoint pen tip extends into the cylinder. A ballpoint pen positioned on the inner surface of a shaped projection . 2. A ball-point pen according to claim 1, wherein the diameter of an imaginary inscribed circle contacting the top of the rear portion of said rib in the axial direction substantially matches the inner diameter of the rear end opening of the ball-point pen tip. 3. The ball-point pen according to claim 1, wherein the thickness of said rib increases toward the rear. A ball-point pen tip having a ball rotatably held at its front end, a rod-shaped ink guide member for supplying ink to the ball of the ball-point pen tip, and an ink occluding body connected to the rear end of the ink guide member. The ball-point pen includes a front shaft to which the ball-point pen tip is fixed and a front end portion of the ink occluding body is housed inside. A plurality of axially extending ribs are integrally formed on the inner surface of the hole at equal intervals in the circumferential direction. and the rear end of the ball-point pen tip is brought into contact with the rear end of the ball-point pen tip, the rear portion of the rib is brought close to the outer surface of the ink guide member, and the outer surface of the ball-point pen tip and the front end An air passage is formed between the ribs and the inner surface of the hole so that the inside of the front shaft can communicate with the outside air. The air passage opens forward from the front end of the front shaft. A tubular protrusion projecting rearward is integrally formed on the inner surface of the front end portion, and the front end hole axially penetrates from the front end of the front barrel to the rear end of the tubular protrusion, and the ballpoint pen tip is provided with the ballpoint pen tip. A ball-point pen , wherein the rear end is positioned on the inner surface of the cylindrical protrusion .

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