JP2023006828A - Ball-point pen - Google Patents

Abstract

To provide a ball-point pen in which the projection amount of a tip body from the front end opening of a barrel can be adjusted.SOLUTION: The ball-point pen includes a refill 3 having a chip body 31 in which a ball is rotatably held in a barrel 2 by an inward front edge portion 31f formed at the front end thereof and a ball receiving seat 31e formed behind a front edge portion 31f, and an ink container arranged behind the chip body 31. The ball-point pen includes a protrusion amount adjustment mechanism in which the front portion of the chip body 31 protrudes from a front end opening 2a of the barrel 2 and which adjusts the amount of protrusion of the chip body 31 that protrudes from the front end opening 2a.SELECTED DRAWING: Figure 1

Description

The present invention relates to ballpoint pens.

Conventionally, in this type of ballpoint pen, Patent Document 1 discloses that an inward front edge portion is formed at the front end of the tip body by caulking deformation, and the front edge portion and the ball receiving seat allow the ball to be held in the ball holding hole. A ballpoint pen is disclosed that is held rotatably and movable back and forth. In the ballpoint pen of Patent Document 1, the ball pressed against the writing surface by the writing pressure at the time of writing retreats while rotating, and ink is discharged from the gap formed between the ball and the front edge, and the ink is discharged onto the writing surface. is transferred via a rotating ball.

In addition, writing instruments including the ballpoint pen are rarely set upright to the writing surface for writing. In the case of , when the inclination of the ballpoint pen is 50° or less with respect to the writing surface as the reference (90° when the ballpoint pen is held perpendicular to the writing surface), the front edge of the tip body will be attached to the writing surface. If you continue writing in this state, the front edge will wear out and you will not be able to hold the ball. When writing, the paper surface is scraped by the front edge that abuts on the writing surface, and the shavings may enter the tip body and interfere with ink ejection, resulting in poor ink delivery such as blurring. . Therefore, it is recommended to write with the tip body at an angle of about 60° to 80° with respect to the writing surface.

On the other hand, in general, when the gripping position of the barrel is fixed during writing, the greater the distance between the pen tip that contacts the writing surface and the grip that grips the ballpoint pen, the more the ballpoint pen tilts relative to the writing surface. As the angle becomes smaller and the distance between the nib and the grip becomes shorter, the ballpoint pen tends to become more perpendicular to the writing surface. However, in the ballpoint pen, the length between the grip portion and the pen tip is fixed and difficult to change.

JP 2016-124194 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a ball-point pen in which the amount of protrusion of the tip body from the front end opening of the barrel can be adjusted.

The present invention comprises a tip body in which a ball is rotatably held by an inward front edge portion formed at the front end and a ball receiving seat formed behind the front edge portion; and the tip body. and a refill having an ink container arranged behind the ballpoint pen, wherein the front part of the tip body protrudes from the front end opening of the barrel,
The ball-point pen is characterized by comprising a protrusion amount adjusting mechanism for adjusting a protrusion amount of the tip protruding from the front end opening.

According to the ball-point pen of the present invention, it has a protrusion amount adjusting mechanism for adjusting the amount of protrusion of the tip body that protrudes from the front end opening of the barrel. For this reason, the user can freely select the amount of protrusion of the tip body, which is the pen tip, when writing. can be increased, and the writing ability can be improved. In addition, when the ballpoint pen is gripped and the pen tip is too far away and the user feels that it is difficult to write, the amount of protrusion can be reduced according to preference. In general, when the gripping position of a writing instrument is fixed, the longer the length from the gripping portion to the pen tip, the greater the inclination of the barrel when writing (the rear end of the barrel is in contact with the writing surface). approach), and conversely, when the length from the grip to the pen tip is shortened, the tilt of the barrel tends to decrease when writing (the rear end of the barrel tends to move away from the writing surface). Therefore, the writing angle during writing can be adjusted by adjusting the amount of protrusion of the tip body.

Further, as a means for adjusting the amount of protrusion of the tip body protruding from the front end opening of the barrel by the protrusion amount adjustment mechanism, the entire length of the barrel extends forward and backward along the axial direction while the position of the tip body is fixed. In this case, the total length of the barrel expands and contracts back and forth along the axial direction, so that the amount of protrusion of the tip body from the front end of the barrel can be changed relatively.

The barrel includes a cylindrical front shaft and a cylindrical rear shaft screwed to the rear portion of the front shaft. A locking projection that is elastically deformable in a radial direction is provided, and a plurality of locking recesses that can be locked with the locking projection are provided on the other, and the projection amount adjustment mechanism is configured by the locking projection and the locking recess. In this case, since the front shaft and the rear shaft are screwed together, the barrel can be axially expanded and contracted by rotating the front shaft with respect to the rear shaft. By locking the projection and the locking recess, the length of the expanded and contracted barrel can be fixed. Further, a plurality of locking recesses may be arranged evenly in the circumferential direction of the front shaft or the rear shaft. In this case, when the front shaft is rotated with respect to the rear shaft, locking and releasing are repeated at regular intervals. . Therefore, the barrel can be expanded and contracted step by step, and the locking protrusion can be fixed at a desired locking position, so that the amount of protrusion of the tip body from the barrel can be adjusted step by step at regular intervals.

In addition, the refill is arranged in the barrel so as to be slidable back and forth along the axial direction, and a retracting mechanism is provided behind the refill for projecting the refill from the front end opening of the barrel. , the retraction mechanism may have the protrusion amount adjustment mechanism, and in this case, the protrusion amount of the tip body can be adjusted by activating the protrusion amount adjustment mechanism in accordance with the refill feeding operation, Easy to operate and highly convenient.

Further, the retractable mechanism is arranged behind the refill and is arranged between an operating body at least partially protruding from an outer peripheral portion or a rear end of the barrel and between the operating body and the refill, A rotating cam member that rotates along a circumferential direction, a cam protrusion formed on the outer peripheral portion of the rotating cam member, and a cam groove formed on the inner peripheral portion of the shaft cylinder, wherein the cam groove includes A plurality of engaging portions that engage with the cam projections may be provided, and the plurality of engaging portions may be formed at different positions along the axial direction for each of the cam grooves. A plurality of mating engaging portions are formed at different positions along the axial direction. Therefore, the axial position of the rotating cam member can be changed by operating the operating body to switch the engaging portion that engages with the cam protrusion to another engaging portion. In addition, since the position of the refill in the front-rear direction can be changed accordingly, the amount of protrusion of the tip body from the barrel can be adjusted.

According to the present invention, it is possible to provide a ball-point pen in which the amount of protrusion of the tip body from the front end opening of the barrel can be adjusted.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view (partial external view) of the ball-point pen in the 1st Embodiment of this invention. 2 is an enlarged longitudinal sectional view showing the front portion (near the ball) of the ballpoint pen of FIG. 1; FIG. 2 is an enlarged end view showing an AA end face in FIG. 1; FIG. 2 is a perspective view showing the appearance of the front barrel of the ball-point pen of FIG. 1; FIG. 2 is a perspective view showing a longitudinal section of the rear barrel of the ball-point pen of FIG. 1; FIG. FIG. 2 is a longitudinal sectional view (partial external view) showing a state in which the front shaft is rotated from the state in FIG. 1; 7 is an enlarged end view showing the BB end face in FIG. 6; FIG. It is a longitudinal cross-sectional view (partial external view) of a ball-point pen according to a second embodiment of the present invention. FIG. 9 is an external view of an operating body of the ballpoint pen of FIG. 8; FIG. 9 is an external view of a rotating cam member of the ballpoint pen of FIG. 8; FIG. 9 is a vertical cross-sectional view showing a state in which the refill has advanced in the ballpoint pen of FIG. 8 ; 12A is a diagram showing the state before knocking, and FIG. 12B is a diagram showing the state after one knocking. FIG. FIG. 12C is a diagram showing the state of knocking twice, and FIG. 12D is a diagram showing the state of knocking three times. 12A to 13D are external views showing the front part of the ballpoint pen in each state of A to D, FIG. 13A is a view showing the front part in FIG. 12A, and FIG. 13B is a view showing the front part in FIG. 12B. 13C is a diagram showing the front part in FIG. 12C, and FIG. 13D is a diagram showing the front part in FIG. 12D.

(First embodiment)
FIG. 1 is a longitudinal sectional view (partial external view) of a ballpoint pen according to a first embodiment of the present invention, and FIG. 2 is an enlarged longitudinal sectional view showing the front portion (near the ball) of the ballpoint pen in FIG. 3 is an enlarged end view showing the AA end face in FIG. 1, FIG. 4 is a perspective view showing the appearance of the front barrel of the ballpoint pen in FIG. 1, and FIG. 5 is the rear side of the ballpoint pen in FIG. FIG. 6 is a longitudinal sectional view (partial external view) showing a state in which the front shaft is rotated from the state of FIG. 1; FIG. It is an enlarged end view showing the B end face.

A ball-point pen 1 of the present embodiment shown in FIG. 1 is a retractable ball-point pen, and includes a barrel 2 having a front end opening 2a at its front end. A refill 3 movable in the axial direction of the barrel 2 is housed inside the barrel 2 so as to be replaceable. The refill 3 has an ink containing cylinder 33 on the rear side, and a chip holder 32 is fixed to the front end of the ink containing cylinder 33 . A tip body 31 is connected to the front end of the tip holder 32 , and the front part of the tip body 31 can protrude and disappear from the front end opening 2 a of the barrel 2 as the refill 3 moves.

The retractable mechanism 4 of the refill 3 of the present embodiment is a rear end knock type retractable mechanism using a rotating cam mechanism. The retracting mechanism 4 includes an engaging portion 22b formed on the inner surface of the rear portion of the barrel 2, a rotating cam member 41 that engages with the engaging portion 22b and contacts the rear end of the refill 3, and the rotating cam member 41. 41 and projecting from the rear end of the barrel 2; Further, the retracting mechanism 4 of the present embodiment is of a double-knock type in which both the operation of projecting the tip body 31 and the operation of retracting the tip body 31 are performed by pressing the operation body 42, which is the operation part, forward. Specifically, when the operation body 42 is moved forward while the refill 3 is retracted, the refill 3 is moved forward, and the front portion of the tip body 31 is pushed out from the front end opening 2 a of the barrel 2 . protrude. The projecting state is maintained by the locking action of the engaging portion 23 and the rotary cam member 41 .

When the operation body 42 is moved forward while the chip body 31 is protruding (the state shown in FIG. 1), the locking state between the engaging portion 22b and the rotary cam member 41 is released. As a result, the refill 3 is returned rearward by the action of the coil spring 5 , and the tip 30 is retracted from the front end opening 2 a of the barrel 2 .

The barrel 2 is composed of a front shaft 21 and a rear shaft 22 screwed to the rear portion of the front shaft 21 .

The front shaft 21 is formed in a cylindrical shape, and as shown in FIGS. The small portion 21a is provided with a male screw portion 21b. A locking projection 21c configured to elastically deform in the radial direction is provided in front of the male screw portion 21b. A slit 21f penetrating to the inner peripheral portion is formed in front and rear of the locking projection 21c, and both ends of the locking projection 21c are connected to the rear small diameter portion 21a. A projecting portion 21d projecting outward is provided at the center of the locking projection 21c. Further, the inner peripheral portion of the front shaft 21 is provided with a groove-shaped portion 21e extending forward from the rear end thereof, and the groove-shaped portion 21e is formed at a position that coincides with the inner peripheral portion of the locking projection 21c. As a result, the locking projection 21c is formed to be thinner than the other portions of the front shaft 21, and is configured to be elastically deformable in the radial direction.

The rear shaft 22 is formed in a cylindrical shape, and has a female threaded portion 22a that is screwed with the male threaded portion 21b on the inner peripheral portion of the front portion. A locking recess 22c is formed in the inner peripheral portion of the rear shaft 22 so as to extend rearward from the front end thereof and engage with the locking projection 21c. A plurality of locking recesses 22c are formed in the inner peripheral portion and are evenly arranged along the circumferential direction. Therefore, when the front shaft 21 is rotated with respect to the rear shaft 22, the locking state between the locking protrusion 21c and the locking recess 22c repeats locking and releasing. Further, the above-described engaging portion 22b is formed on the inner peripheral portion of the rear portion of the rear axle 22. As shown in FIG.

As shown in FIG. 2, the refill 3 has a tip body 31 made of a stainless steel wire, a ball holding chamber 31a, an ink circulation hole 31b in the center of the ball holding chamber 31a, and the ink circulation hole 31b. A ball 34 made of tungsten carbide with a diameter of 0.7 mm is provided on a bottom wall 31e which is formed at the rear of the ball holding chamber 31a and serves as a ball receiving seat. is placed on the chip body 31 and the tip of the tip body 31 is crimped to form a front edge 31f. As a result, the ballpoint pen tip 31 rotatably held so that a part of the ball 34 protrudes from the front edge 31f is attached to the tip of the ink container 33 via the tip holder 32 .

Next, referring to FIGS. 1, 3, and 6 to 8, the front shaft 21 is rotated with respect to the rear shaft 22 from the state shown in FIG. A state in which the amount of protrusion of the front portion of the tip body 31 from the front end opening 2a of the (shaft tube 2) changes will be described.

In the state shown in FIG. 1, the tip body 31 of the refill 3 protrudes from the front end opening 2a of the barrel 2 by a length L1, and the locking protrusion 21c of the front barrel 21 and the locking recess 22c of the rear barrel 22 are locked. is.
From the state shown in FIG. 1, when the front shaft 21 is rotated with respect to the rear shaft 22 in the direction in which the screwing is released, the locking projection 21c is elastically deformed inward, and the locking projection 21c and the locking recess 22c are separated. is temporarily released. Then, when the locking projection 21c of the front shaft 21 rotated with respect to the rear shaft 22 reaches the position of the adjacent locking recess 22c, the locking projection 21c and the locking recess 22c are locked again. The state shown in FIG. 7 is obtained. At this time, since the screwing between the front shaft 21 and the rear shaft 2 continues, the front shaft 21 advances relative to the rear shaft 22 by the amount of the rotation of the front shaft 21, and the front end 22c of the rear shaft 22 and the front shaft 22 move forward. is separated from the outer peripheral step portion 21g of , and a gap is generated. Then, the amount of protrusion of the tip body 31 from the front shaft 21 corresponding to the gap is reduced from L1 in FIG. 1 to L2 in FIG. Since six locking recesses 22c are formed on the inner surface of the rear axle 22 at intervals of 60°, when rotated from FIG. 3 to the state shown in FIG. 21 has been rotated 60° with respect to the rear axle 22 . In the present embodiment, since the thread pitch of the male thread portion 21b and the female thread portion 22a is 2 mm, when the front shaft is rotated by 60°, the front shaft 21 advances 0.33 mm relative to the rear shaft 22. do. Therefore, the amount of protrusion of the tip body 31 from the front shaft 21 is reduced by 0.33 mm.

Accordingly, in the present embodiment, the front shaft 21 is rotated with respect to the rear shaft 22, and the locking projection 21c and the locking concave portion 22c are repeatedly locked and unlocked, whereby the front shaft 21 and the rear shaft 22 are rotated. The amount of protrusion of the front portion of the tip body 31 from the front shaft 21 can be changed stepwise at intervals of 0.33 mm unless the screwing of the tip body 31 is released. That is, the screwing of the male screw portion 21b and the female screw portion 22a, and the locking of the locking protrusion 21c and the locking recess 22c constitute a protrusion amount adjusting mechanism of the chip body 31. As shown in FIG. The amount of protrusion of the tip body 31 from the front shaft 21 can be determined by changing the arrangement interval and the number of locking recesses 22c, or by changing the thread pitch of the male screw portion 21b and the female screw portion 22a. can be changed to

Further, in this embodiment, when the locking projection 21c is locked with the locking recess 22c, the locking projection 21c may be pressed inward by the locking recess 22c. In this case, since the engaging recess 22c is configured to be elastically deformable in the radial direction, when the engaging projection 21c and the engaging recess 22c are in the engaged state, the elastic force of the engaging projection 21c causes the front shaft 21 to move. The rear barrel 22 is firmly fixed to prevent rattling when writing. Furthermore, in order to further prevent backlash between the front axle 21 and the rear axle 22, a coil spring is arranged between the front axle 21 and the rear axle 22 to bias the front axle 21 against the rear axle 22. You may let

(Second embodiment)
8 is a longitudinal sectional view of a ballpoint pen according to a second embodiment of the present invention, FIG. 9 is an external view of the operation body of the ballpoint pen of FIG. 8, and FIG. 10 is a rotating cam member of the ballpoint pen of FIG. 11 is a vertical cross-sectional view showing a state in which the refill of the ballpoint pen shown in FIG. 12A is a diagram showing a state before knocking, FIG. 12B is a diagram showing a state in which the operating body is knocked once, and FIG. 12C is a state in which the operating body is knocked twice. FIG. 12D is a diagram showing a state in which the operating body is knocked three times; 13B is a diagram showing the front part in FIG. 12A, FIG. 13B is a diagram showing the front part in FIG. 12B, FIG. 13C is a diagram showing the front part in FIG. 12C, and FIG. 13D is a diagram showing the front part in FIG. 12D It is the figure which showed the part.

In the second embodiment, parts having the same structure as those in the first embodiment are denoted by the same reference numerals, and description thereof is partially omitted.

A ballpoint pen 101 of the second embodiment shown in FIG. 8 is a retractable type ballpoint pen, and includes a barrel 102 having a front end opening 102a at its front end. Inside the barrel 102, a replaceable refill 3 is accommodated which is movable in the axial direction of the barrel 102. As shown in FIG. As the refill 3 moves, the front portion of the tip body 31 is configured to be retractable from the front end opening 102a of the barrel 102. As shown in FIG.

The retracting mechanism 104 of the refill 3 of the present embodiment is a rear end knock type retracting mechanism using a rotating cam mechanism. The retracting mechanism 104 includes a cam groove 122a and an engaging portion 122b formed on the inner surface of the rear portion of the barrel 102, a rotating cam member 141 that engages with the engaging portion 122b and contacts the rear end of the refill 3, an operating body 142 that engages with the rotary cam member 141 and protrudes from the rear end of the barrel 102; a coil spring 5 (for example, a compression coil spring) that is accommodated in the barrel 2 and biases the refill 3 rearward; consists of In addition, the retracting mechanism 104 of the present embodiment is of a type in which the operation body 142, which is an operation unit, is pressed forward for both the pen tip projecting operation and the pen tip retracting operation.

The barrel 102 is composed of a front shaft 121 and a rear shaft 122 screwed to the rear portion of the front shaft 121 .

As shown in FIG. 12, the inner peripheral portion of the rear shaft 122 has a plurality of cam grooves 122a formed at regular intervals along the circumferential direction. The cam groove 122a has a deep cam groove 122a1 and a plurality of shallow cam grooves 122a2. Furthermore, the front ends of the plurality of shallow cam grooves 122a2 are provided with engaging portions 122b. The engaging portion 122b has a slope portion and has a first locking slope 122c, a second locking slope 122d, and a third locking slope 122e formed at different positions along the axial direction. are doing.

The operating body 142 has an uneven meshing portion 142b at its tip, and has a plurality of sliding protrusions 142a on its outer surface that engage and slide in the cam grooves 122a. They are provided at equal intervals on the circumference.

The rotating cam member 141 is disposed in front of the operating body 142, and has a cam projection 141a that slides and rotates in the cam groove 122a and is engaged with an engaging portion 122b provided at the front end of the cam groove 122a. are doing. Further, the rear end portion of the rotary cam member 141 is provided with a meshed portion 141c composed of an inclined surface 141b that meshes with the meshing portion 142b formed on the rotary cam member 141. As shown in FIG. As a result, the operating body 142 and the rotating cam member 142 are arranged in series with the meshed portion 141c meshing with the meshing portion 142b.

Next, referring to FIGS. 8 and 11 to 13, the operation of causing the front portion of the tip body 31, which is the pen tip, to protrude from the front end opening 102a of the barrel 2 and changing the amount of protrusion of the tip body 31. I will explain about.

In the ballpoint pen 101 shown in FIGS. 8 and 13A, when the knock portion 142d of the operating body 142 protruding from the rear end opening 102b of the barrel 102 is pushed forward of the barrel 2 (first knocking motion), the operating body 142 advances guided by sliding projections 142a engaged with deep cam grooves 122a1 and shallow cam grooves 122b1 formed on the inner surface of the barrel 2, and the rotating cam member 141 connected to the operating body 142 moves forward along the deep cam grooves. It moves forward guided by the cam projection 141a engaged with 122a1 (see FIG. 12A).
When the cam protrusion 141a reaches the tip of the deep cam groove 122a1 and leaves the cam groove 122a, the top portion 142c of the engaging portion 142b of the operating body 142 moves to the middle of the inclined surface 141b of the engaged portion 141c of the rotary cam member 141. To position. At this time, since the rotating cam member 142 is in contact with the refill 3 that is elastically pushed backward by the coil spring 5 engaged with the barrel 2, it rotates from right to left in an attempt to retreat backward (see FIG. 12, (because the inclined surface 141b of the meshed portion 141c slopes downward to the right), the meshed portion 141c of the rotary cam member 141 slides on the meshing portion 142b of the operating body 142, and the meshed portion 141c of the cam protrusion 141a is formed in the shallow cam groove 122a2. 12B by being locked by the first locking slope 122c at the tip, and as shown in FIG. can be done. At this time, as shown in FIG. 13B, the front portion of the tip body 31 protrudes from the front end of the shaft tube 2 by a protrusion amount L'1.

Further, by pushing the knocking portion 142d of the operating body 142 forward with respect to the barrel 2 again (second knocking operation), the meshed portion 141c of the cam projection 141a and the shallow cam groove 122a2 are first locked. The locked state with the inclined surface 122c is released, and the rotating cam member 141, which is elastically energized by the coil spring 5, rotates from the right side to the left side in an attempt to retreat (in FIG. ), the cam protrusion 141a of the rotary cam member 141 retreats in the shallow cam groove 122a2, and the meshed portion 141c is locked by the second locking slope 122d, resulting in the state shown in FIG. 12C. Then, as shown in FIG. 13C, the tip body 31 protrudes from the front end of the barrel 2 by a protrusion amount L'2.

Further, by pushing the knocking portion 142d of the operating body 142 forward with respect to the barrel 2 again (the third knocking operation), the engaged portion 141c of the cam projection 141a and the shallow cam groove 122a2 are engaged with each other for the second locking. The locked state with the inclined surface 122d is released, and the rotating cam member 141, which is elastically energized by the coil spring 5, rotates from the right side to the left side in an attempt to retreat (in FIG. ), the cam protrusion 141a of the rotary cam member 141 retreats in the shallow cam groove 122a2, and the engaged portion 141c is locked by the third locking slope 122e, resulting in the state shown in FIG. 12D. Then, as shown in FIG. 13D, the tip body 31 protrudes from the front end of the barrel 2 by a protrusion amount L'3.

Here, the axial positions of the first locking slope 122c, the second locking slope 122d, and the first locking slope 122e will be described. The second locking slope 122d is formed 1 mm behind the first locking slope 122c, and the third locking slope 122e is formed further 1 mm behind the second locking slope 122d. Therefore, the amount of protrusion of the front portion of the tip body 31 retreats by 2 mm from L1 to L3. In the present embodiment, the amount of protrusion L'1 in FIG. 13B is 4 mm, so the amount of protrusion L'2 in FIG. 13C is 3 mm, and the amount of protrusion L'3 in FIG. 13D is 2 mm. The amount of protrusion of the main body 31 can be adjusted. That is, the feeding mechanism 104 has a mechanism for adjusting the protrusion amount of the tip body 31 .

Further, by pushing the knocking portion 142d of the operating body 142 forward with respect to the barrel 2 again (fourth knocking operation), the meshed portion 141c of the cam projection 141a and the shallow cam groove 122a2 are engaged in the third engagement. The locked state with the inclined surface 122e is released, and the rotating cam member 141 rebounded by the coil spring 5 rotates from the right side to the left side in an attempt to retreat (in FIG. ), the cam protrusion 141a of the rotary cam member 141 retreats through the deep cam groove 122a1 to enter the state shown in FIG. 12A, and as shown in FIGS. The front part is immersed.

As described above, in the first embodiment and the second embodiment of the present invention, the amount of protrusion of the tip body that protrudes from the front end of the barrel can be switched in stages. Therefore, the user can arbitrarily select the amount of projection of the tip body, which is the pen tip, during writing. As a result, when the user feels that the visibility of the pen tip is poor, the visibility of the pen tip can be improved by increasing the amount of protrusion of the tip body, and the writing performance can be improved. In addition, when the ballpoint pen is gripped and the pen tip is too far away and the user feels that it is difficult to write, the amount of protrusion can be reduced according to preference. In general, when the gripping position of a writing instrument is fixed, the longer the length from the gripping portion to the pen tip, the greater the inclination of the barrel when writing (the rear end of the barrel is in contact with the writing surface). approach), and conversely, when the length from the grip to the pen tip is shortened, the tilt of the barrel tends to decrease when writing (the rear end of the barrel tends to move away from the writing surface). For this reason, the inclination of the ball-point pen is 50° or less with respect to the writing surface (when the ball-point pen is set vertically to the writing surface at 90°), and the front edge of the tip body is in contact with the writing surface. If there is a risk that the (crimped portion) will come into contact with the pen tip, the amount of protrusion of the tip body from the barrel may be adjusted to be small in order to shorten the distance from the grip portion to the pen tip. In this case, when the user grips the ballpoint pen and writes, the user is naturally prompted to stand the ballpoint pen and write. As a result, the front edge comes into contact with the writing surface, and the front edge wears away, making it impossible to hold the ball. In this case, the paper surface is scraped off by the front edge that abuts on the writing surface, and the shavings enter the tip body, inhibiting ink ejection and preventing ink ejection defects such as blurring.

1 ballpoint pen 2 barrel 2a front end opening 21 front shaft 21a rear small diameter portion 21b male screw portion 21c locking projection 21d protrusion
21e groove-shaped portion 21f slit 21g outer peripheral stepped portion 22 rear shaft 22a female screw portion 22b engaging portion 22c engaging recess 3 refill 31 tip body 31a ball holding chamber 31b ink circulation hole 31c ink circulation groove 31d tip rear hole 31e bottom wall (ball receiving seat)
31f Front end edge 32 Tip holder 33 Ink container 34 Ball 4 Protruding/retracting mechanism 41 Rotating cam member 42 Operating body 5 Coil spring 101 Ballpoint pen 102 Axle 102a Front end opening
102b rear end opening 121 front shaft 122 rear shaft 122a cam groove 122a1 deep cam groove
122a2 Shallow cam groove 122b Engagement portion 122c First locking slope 122d Second locking slope 122e Third locking slope 104 Retractable mechanism 141 Rotating cam member 141a Cam projection 141b Inclined surface 141c Engaged portion 142 Operating body 142a Sliding projection 142b meshing portion 142c top portion 142d knock portion L1 amount of protrusion L2 amount of protrusion L'1 amount of protrusion L'2 amount of protrusion
L'3 Projection amount

Claims (5)

A tip body in which a ball is rotatably held by an inward front edge portion formed at the front end and a ball receiving seat formed behind the front edge portion, and a tip body disposed behind the tip body. a ballpoint pen in which a front portion of the tip body protrudes from a front end opening of the barrel, wherein
A ball-point pen, comprising a protrusion amount adjusting mechanism for adjusting a protrusion amount of the tip body protruding from the front end opening. 2. The ball-point pen according to claim 1, wherein the length of the shaft cylinder along the axial direction can be expanded and contracted as the protrusion amount adjusting mechanism. The barrel includes a cylindrical front shaft and a cylindrical rear shaft screwed to a rear portion of the front shaft, and radially extends either to the rear portion of the front shaft or to the front portion of the rear shaft. One of them is provided with a locking projection that elastically deforms, and the other is provided with a plurality of locking recesses that can be locked with the locking projection, and the projection amount adjustment mechanism is constituted by the locking projection and the locking recess. 3. The ballpoint pen according to claim 2, characterized in that: The refill is arranged in the barrel so as to be slidable back and forth along the axial direction, and has a protruding/retracting mechanism behind the refill for projecting the refill from the front end opening of the barrel, 2. The ball-point pen according to claim 1, wherein the projection/retraction mechanism has the projection amount adjustment mechanism. The retractable mechanism is arranged behind the refill, and is arranged between an operation body, at least a part of which protrudes from an outer peripheral portion or a rear end of the barrel, and the refill, and is arranged between the operation body and the refill. a rotating cam member that rotates along, a cam protrusion formed on the outer peripheral portion of the rotating cam member, and a cam groove formed on the inner peripheral portion of the shaft cylinder,
The cam groove has a plurality of engaging portions that engage with the cam protrusions, and the plurality of engaging portions are formed at different positions along the axial direction for each cam groove. The ballpoint pen according to claim 4.

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