JP2009255427A - Knock-type writing instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a knock-type writing instrument in which a writing tip of a writing body housed in a barrel cylinder and energized backward movably back and forth by a spring, appears/disappears from the tip opening of the barrel cylinder by the rotation of the writing body together with the rotation of a rotary cam by a knock-type delivery mechanism comprising a cam groove, a fixed cam, the rotary cam and a knock body which are housed in the barrel cylinder, and in which knock sounds generated by the rotary cam during the knocking operation of the knock body is reduced. <P>SOLUTION: A rotation suppression member 16 is bonded to the tip surface 8a of a rotary cam 8, and the peripheral side face 16a of the rotation suppression member 16 abuts on the inner wall surface of a the barrel cylinder 2. An air passage hole 17 is disposed in the rotation suppression member 16. The space part 12 of a ballpoint pen refill 6 is communicated with the outside of the barrel cylinder 2 via an air ventilation hole 13 and a recessed groove 14 of a tail tap 11, the air passage hole 17 of the rotation suppression member 16, and a through-space part 18 of the rotary cam 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a knock-type writing instrument having a knock-type feeding mechanism composed of a cam groove, a fixed cam, a rotating cam, and a knock body.

  Conventionally, a writing tip of a writing body which is urged backward by a spring in a shaft cylinder and is movably moved back and forth, has a cam groove and a protrusion engaging with the cam groove on the peripheral side. A fixed cam provided so as to be movable back and forth along a cam groove having a concavo-convex portion, and a front end having a meshing portion engaging with the concavo-convex portion having a cam projection engaging with the cam groove on a peripheral side portion. A knock-type feeding mechanism comprising a rotating cam that is in contact with the rear end portion of the writing body, is connected to the fixed cam at the rear end and is movable back and forth along the cam groove, and a knock body for pressing the fixed cam. Thus, a knock-type writing instrument is known in which the writing body rotates with the rotation of the rotary cam so as to appear and disappear from the tip opening of the shaft cylinder. In such a knock-type writing instrument, when the knock body is pressed, the fixed cam pressed by the knock body advances without rotation because the protrusion provided on the fixed cam is engaged with the cam groove, Since the cam protrusion provided on the rotating cam engages with the cam groove and is pressed by the protrusion, the cam moves forward in conjunction with the fixed cam. The writing body in contact with the rotating cam also moves forward in conjunction with it, and the writing tip portion projects from the tip opening portion of the shaft tube. When the cam projection provided on the rotating cam comes to the tip of the cam groove, it rotates and locks to the locking portion of the cam groove, and the retraction of the rotating cam is suppressed. Maintain a protruding state. In order to immerse the writing tip in the shaft cylinder, the knocking body is pressed again to advance the rotating cam, and the rotating cam rotates to release the locking with the locking portion of the cam groove of the rotating cam. As a result, the rotating cam and the fixed cam are pushed backward through the writing body biased to the rear end side by the spring, so that the rotating body and the writing body are also retracted, and the writing front end portion is immersed in the shaft cylinder.

  However, in a knock type writing instrument having a feeding mechanism composed of such cam grooves, rotating cams, and fixed cams, the knocking operation for causing the writing tip of the writing body to protrude from the tip opening of the shaft tube must be performed. A knocking sound was generated. Such a knocking sound may cause discomfort to surrounding people in an environment where a slight sound resonates during a meeting or the like. In addition, for expensive writing instruments, there is a problem that knocking sound that is larger than necessary impairs the sense of quality. As a result of various investigations by the present inventor to reduce such knock noise, the knock noise is an impulsive sound when the rotating cam rotates and engages with the engaging portion of the cam groove. A knocking sound generated when the rotating cam advances and rotates by the knocking operation for immersing the writing tip into the tip opening of the shaft tube, and the cam projection hits the wall surface of the adjacent cam groove. I found out.

  The cause of the occurrence of the contact noise will be described in detail with reference to FIGS. 7 to 9. FIG. 7 is a side view of a general fixed cam, and FIG. 8 is a side view of a general rotary cam. FIG. 9 is a conceptual diagram showing a positional relationship among a cam groove, a concavo-convex portion and a projection of a fixed cam, and a meshing portion and a cam projection of a rotating cam in a conventional knock type ballpoint pen.

  In general, as shown in FIG. 7, the fixed cam 51 has a mountain-shaped uneven portion 52 at the tip, and a plurality of protrusions 53 that engage with cam grooves arranged in the shaft cylinder of the writing instrument on the outer peripheral surface. The protrusions 53 are formed so as to be positioned in the line shape (one-point difference line shape) of the top portion 52 a of the uneven portion 52. In general, as shown in FIG. 8, the rotating cam 54 is provided with a plurality of cam projections 55 that engage with the cam grooves on the outer circumferential surface, and the rear end (upper portion in the figure) of the cam projection 55 is the concave / convex A meshing portion 56 constituted by an inclined surface 56 a meshing with the portion 52 is provided.

  As shown in FIG. 9, when the protrusion 53 of the fixed cam 51 and the cam protrusion 55 of the rotating cam 54 are engaged with the cam groove 57, the top 52 a of the concavo-convex portion 52 is at the midpoint of the inclined surface 56 a of the meshing portion 56. It is provided to be located. When a knock body (not shown) is pressed toward the distal end of the shaft tube, the fixed cam 51 is guided to the protrusion 53 engaged with the deep cam groove 57-1 and the shallow cam groove 57-2 in conjunction with the knock body. The rotating cam 54 connected to the fixed cam 51 is guided and advanced by the cam protrusions 55a and 55b engaged with the deep cam groove 57-1. When the cam protrusions 55a and 55b reach the tip of the deep cam groove 57-1 and leave the cam groove 57-1, the top 52a of the uneven portion 52 of the fixed cam 51 is in the middle of the inclined surface of the meshing portion 56 of the rotating cam 54. The rotating cam 54 is in contact with the rear end of a writing body (not shown) urged rearward by a spring (not shown), so that the rotating cam 54 tries to move backward to the right side. To the left (in the figure, the inclined surface 56a of the meshing portion 56 is lowered to the right), the meshing portion 56 of the rotating cam 54 slides on the concavo-convex portion 52 of the fixed cam 51, and the cam projection 55a It contacts the inclined wall surface 59-1. At this time, a first knocking sound is generated.

  Next, the meshing portion 56 of the cam projection 58 a of the rotating cam 54 slides on the inclined wall surface 59-1, and the rear end (upper side in the drawing) of the cam projection 55 a hits the adjacent projection piece 58 b constituting the locking portion 60. Contact and lock to the locking portion 60. At this time, a second knocking sound is generated by the cam protrusion 55a of the rotating cam 54 coming into contact with the protruding piece 58b.

  When the writing tip of the writing body is immersed in the opening of the tip of the shaft cylinder, the fixed cam 51 and the rotating cam 54 are moved forward by the pressure of the knocking body (not shown), and the rotating cam for the same reason as described above. When 54 is rotated backward (from the right side to the left side in the figure) and is disengaged from the locking portion 60, the meshing portion 56 of the rotating cam 54 slides on the uneven portion 52 of the fixed cam 51, and the cam protrusion 55a It contacts the inclined wall surface 59-2 at the tip of the projecting piece 58b. At this time, a third knocking sound is generated.

  Next, the meshing portion 56 of the cam projection 58a of the rotating cam 54 slides on the inclined wall surface 59-2, and the rear end (upper side in the drawing) of the cam projection 55a abuts against the wall surface 61 of the adjacent projecting piece 58c. Retreats along the groove 57-1, and returns to the original position. At this time, a fourth knocking sound is generated by the cam protrusion 55a of the rotating cam 54 coming into contact with the protruding piece 58c.

Therefore, it has been found that in order to reduce these four knocking noises, it is only necessary to weaken the rotational force and rotational speed of the rotary cam, and the present invention has been achieved. In a knock-type writing instrument in which the writing body rotates with the rotation of the rotating cam and protrudes and retracts from the opening at the tip of the shaft tube, at least a part of the writing material hits the inner wall surface of the shaft tube in order to reduce the rotational force and rotation speed of the rotating cam. The problem can be solved by providing a rotation-suppressing member in contact with the rotating cam or the cursive body so that the rotation cam is directly or indirectly added to the rotating cam. Conventionally, an extrusion-type ballpoint pen (knock-type ballpoint pen) In Japanese Laid-Open Patent Application No. 57-163376, an elastic member (5) for buffering the writing pressure is interposed between the rotating cam (202) and the end of the ink tube with ball (3). Although the coil spring is disclosed as the elastic member (5) for buffering the writing pressure, it is only an elastic member for buffering the writing pressure, and the rotational force when the rotating cam (202) rotates. It does not weaken the rotation speed. Japanese Patent No. 3197444 discloses a technique in which an elastic body for absorbing shock is provided at the abutting portion of the knocking portion where the rear end of the refill abuts. The elastic body does not weaken the rotational force or rotational speed of the rotating cam, and is not a knock-type feeding mechanism having a fixed cam and a rotating cam.
Japanese Utility Model Publication No. 57-163376 Japanese Patent No. 3197444

  The present invention has a writing tip portion of a writing body that is urged rearward by a spring in a shaft cylinder so as to be movable back and forth, a cam groove, and a protrusion engaging with the cam groove on a peripheral side portion. A fixed cam provided to be movable back and forth along a cam groove having a concavo-convex portion at the tip, and a front end having a meshing portion that has a cam projection that engages with the cam groove on the peripheral side portion and meshes with the concavo-convex portion A knock-type feeding comprising a rotating cam that comes into contact with the rear end portion of the cursive body, is connected to the fixed cam at the rear end and is movable back and forth along the cam groove, and a knock body for pressing the fixed cam. A knock-type writing instrument that reduces the knocking noise generated by the rotating cam during knocking operation of the knock body in a knock-type writing instrument in which the writing body rotates with the rotation of the rotating cam and protrudes and retracts from the opening of the end of the barrel. To do.

The present invention
“1. A writing tip of a writing body which is urged backward by a spring in a shaft tube and is movably moved back and forth, has a cam groove and a protrusion engaging with the cam groove on the peripheral side. A fixed cam provided so as to be movable back and forth along a cam groove having a concavo-convex portion, and a front end having a meshing portion engaging with the concavo-convex portion having a cam projection engaging with the cam groove on a peripheral side portion. A knock-type feeding mechanism comprising a rotating cam that is in contact with the rear end portion of the writing body, is connected to the fixed cam at the rear end and is movable back and forth along the cam groove, and a knock body for pressing the fixed cam. Thus, in the knock-type writing instrument in which the writing body rotates along with the rotation of the rotating cam and protrudes and retracts from the tip opening of the shaft cylinder, at least a part of the writing body abuts against the inner wall surface of the shaft cylinder. At least on the circumferential side surface of the cursive body and / or Some are provided rotation control member so as to contact the inner wall surface of the barrel, knock-type writing instrument is characterized in that weakened the rotational force and rotation speed of the rotary cam during knocking operation. "
It is.

In the present invention, it is important that at least a part of the rotation restraining member is provided so as to abut against the inner wall surface of the shaft cylinder. However, in the conventional knock type writing instrument, the cam groove forming the knock type feeding mechanism is provided. Some are different. Briefly described with reference to FIGS. 5 and 6, the conventional general knock-type ballpoint pen 1 is provided with a cam groove 3 formed on the inner wall surface of the rear end portion 2 a of the shaft tube 2. Is projected from the rear end opening 2b of the shaft tube 2. In front of the knock body 4, there are a plurality of protrusions (not shown) having a mountain-shaped uneven portion (not shown, see FIG. 7) at the tip and engaging the cam groove 3 on the outer peripheral surface. First, a fixed cam portion 5 formed by arranging a circumferential shape in a circumferential shape is integrally provided, and a protrusion is engaged with the cam groove 3. A plurality of cam projections (not shown, see FIG. 8) that engage with the cam groove 3 are provided on the outer circumferential surface in front of the knock body 4, and mesh with the concave and convex portions of the fixed cam portion 5. A rotating cam 8 having a locking portion 7 with which a rear end 6a of the ballpoint pen refill 6 is locked, and a cam projection engaged with the cam groove 3 It is provided so as to be movable back and forth along the groove 3. The rotating cam 8 has a shaft portion 9 located in the knock body 4.

  Regarding the cam groove of such a knock-out mechanism, the difference in the shape of the rotating cam and the setting of the moving distance forward of the rotating cam for projecting the writing tip of the writing body from the tip opening of the shaft cylinder are shown in FIG. As shown in FIG. 4, in a state where the ballpoint pen tip (not shown) of the ballpoint pen refill 6 is immersed in the shaft cylinder 2, the front end surface 8 a of the rotating cam 8 is in front of the front end 10 a of the projecting piece 10 constituting the cam groove 3 ( In the state where the ballpoint pen tip of the ballpoint pen refill 6 is immersed in the shaft cylinder 2 as shown in FIG. Are provided so as to be located rearward (right side in FIG. 6) of the tip 10a of the projecting piece 10 constituting. Of course, it is important to provide a rotation suppressing member interposed between the rotating cam and the writing body so as not to prevent the rotating cam from moving back and forth along the cam groove.

  Incidentally, in the knock type ballpoint pen 1 shown in FIGS. 5 and 6, a tail plug 11 is inserted into the rear end of the ballpoint pen refill 6, and ink (not shown) in the ballpoint pen refill 6 is inserted into the tail plug 11. An air hole (not shown) that communicates between the rear space (not shown) and the outside of the ballpoint pen refill 6 is provided. Further, the rear end surface 11a of the tail plug 11 is provided with a concave groove (not shown) connected to the air hole, and a projection (not shown) formed on the locking portion 7 of the rotary cam 8 is engaged. Thus, the ballpoint refill 6 can be rotated in conjunction with the rotation of the rotary cam 8.

  In the knock-type writing instrument having the former structure as shown in FIG. 5, it is possible to arrange a rotation suppression member between a portion of the rotating cam that abuts on the rear end portion of the writing body and the rear end portion of the writing body. However, in the knock-type writing instrument having the latter structure as shown in FIG. 6, the rotation suppression member abuts against the projecting piece constituting the cam groove in a state where the writing tip of the writing body is immersed in the shaft cylinder. Therefore, it is important to provide the rotary cam so as not to prevent the backward movement of the rotary cam. For this purpose, it is necessary to provide the rotation suppression member at a position on the tip opening side of the shaft tube where the writing tip portion of the writing body appears and disappears from the tip of the projecting piece constituting the cam groove. Since the cursive body rotates with the rotation of the rotating cam and appears and disappears from the opening of the tip of the shaft cylinder, indirectly by reducing the rotational force and rotational speed of the cursive body accompanying the rotation of the rotating cam during the knocking operation. It is possible to weaken the rotational force and rotational speed of the rotating cam. Therefore, in the knock type writing instrument having such a structure, the object can be achieved by providing the rotation suppressing member on the peripheral side surface of the writing body.

  As the rotation suppressing member, a member having a high surface frictional resistance is preferable. For example, various materials such as solid rubber, foam plastic, rough surface plastic, metal, wood, leather, paper material, cloth material, stone material, clay, etc. can be mentioned. Each material can be used alone or in combination of two or more. Can also be used. As the rotation suppressing member, solid rubber is preferable in view of the variety, processability, durability, light weight, and availability. Examples of the solid rubber include natural rubber, isoprene rubber, butadiene rubber, diene special rubber, olefin rubber, ether rubber, polysulfide rubber, urethane rubber, fluorine rubber, silicone rubber, and thermoplastic elastomer.

  Since the knock type writing instrument of the present invention has the structure as described above, the cam protrusion of the rotating cam is brought into contact with the locking portion of the cam groove when the writing tip portion of the writing body is projected and retracted from the tip opening portion of the shaft cylinder by the knocking operation. The impact sound generated by the impact of the projecting piece that forms the locking part when locked, and the cam protrusion of the rotating cam when the writing tip of the writing body is immersed from the tip opening of the shaft cylinder are adjacent to each other. The contact noise generated by contact with the projecting piece forming the cam groove when engaging with the cam groove is reduced because the rotational force and rotational speed of the rotating cam are weakened.

  The knock type writing instrument of the present invention is known in the art, the writing tip portion of the writing body that is urged backward by a spring in the shaft cylinder and is movably moved back and forth, a cam groove, a fixed cam, In a knock type writing instrument in which a writing body rotates with the rotation of the rotating cam and protrudes and retracts from the tip opening of the shaft cylinder by a knock type feeding mechanism constituted by a rotating cam and a knock body for pressing the fixed cam. And / or a curving body and / or a peripheral surface of the cursive body is provided with a rotation suppressing member so that at least a part thereof abuts against the inner wall surface of the shaft tube.

  This embodiment will be described with reference to FIGS. 1 to 4. In this embodiment, a knock ballpoint pen will be described as an example of a knock writing instrument, but the present invention is not limited to this. In the drawings, the same members and the same parts are denoted by the same reference numerals. FIG. 1 shows a first embodiment of the present invention, in which the tip end surface of the rotating cam is positioned in front of the tip end of the projecting piece constituting the cam groove when the writing tip end portion of the writing body is immersed in the shaft cylinder. It is a longitudinal cross-sectional view of the feeding mechanism part of the knock type ball-point pen which has a feeding structure. FIG. 2 shows a second embodiment of the present invention, in which the tip end surface of the rotating cam is positioned in front of the tip end of the projecting piece constituting the cam groove when the writing tip end portion of the writing body is immersed in the shaft cylinder. It is a longitudinal cross-sectional view of the feeding mechanism part of the knock-type ball-point pen which has the extended drawing structure. FIG. 3 shows a third embodiment of the present invention, in which the front end surface of the rotating cam is positioned in front of the front end of the projecting piece constituting the cam groove when the writing front end portion of the writing body is immersed in the shaft cylinder. It is a longitudinal cross-sectional view of the feeding mechanism part of the knock type ball-point pen which has a feeding structure. FIG. 4 shows a fourth embodiment of the present invention, in which the tip end surface of the rotating cam is located behind the tip end of the projecting piece constituting the cam groove when the writing tip end portion of the writing body is immersed in the shaft cylinder. It is a longitudinal cross-sectional view of the feeding mechanism part of the knock type ball-point pen which has a feeding structure.

  The knock type ballpoint pen 1 of the first embodiment shown in FIG. 1 has the same structure as a conventional knock type ballpoint pen, and is provided with a cam groove 3 formed on the inner wall surface of the rear end 2a of the shaft tube 2. The knock body 4 is provided so as to protrude from the rear end opening 2 b of the shaft cylinder 2. A front portion of the fixed cam portion 5 has a mountain-shaped uneven portion (not shown, see FIG. 7) at the tip, and a plurality of protrusions (not shown) engaged with the cam groove 3 on the outer peripheral surface. , Refer to FIG. 7), and a fixed cam portion 5 that is arranged in a circumferential shape is integrally provided, and a protrusion is engaged with the cam groove 3. A plurality of cam projections (not shown, see FIG. 8) that engage with the cam groove 3 are provided on the outer circumferential surface in front of the fixed cam portion 5 and mesh with the concave and convex portions of the fixed cam portion 5. A rotating cam 8 having an engaging portion (not shown, see FIG. 8) and having a locking portion 7 to which the rear end 6a of the ballpoint pen refill 6 is locked is engaged with the cam protrusion in the cam groove 3. It is provided so as to be movable back and forth along the cam groove 3. The rotating cam 8 has a shaft portion 9 located in the knock body 4. In a state where a ballpoint pen tip (not shown) of the ballpoint pen refill 6 is immersed in the shaft cylinder 2, the front end surface 8 a of the rotating cam 8 is positioned in front of the front end 10 a of the projecting piece 10 constituting the cam groove 3.

  A tail plug 11 is inserted at the rear end of the ball-point pen refill 6, and the tail plug 11 communicates with the space 12 behind the ink (not shown) in the ball-point refill 6 and the outside of the ball-point refill 6. A hole 13 is provided. Further, the rear end surface 11 a of the tail plug 11 is provided with a concave groove 14 connected to the air vent hole 13, and the protrusions 15 provided at two positions facing the locking portion 7 of the rotating cam 8 are engaged. As the rotary cam 8 rotates, the ballpoint refill 6 can also rotate.

  In the first embodiment of the present invention, a rotation suppressing member 16 made of nitrile rubber is bonded to the tip end surface 8 a of the rotating cam 8, and the peripheral side surface 16 a of the rotation suppressing member 16 contacts the inner wall surface of the shaft cylinder 2. It is in contact. The rotation suppressing member 16 is provided with an air passage hole 17, and the space 12 of the ballpoint pen refill 6 has an air vent hole 13 and a concave groove 14 of the tail plug 11, an air passage hole 17 of the rotation suppressing member 16, and a rotating cam 8. The through space 18 communicates with the outside of the shaft cylinder 2.

  By providing the rotation suppressing member 16 on the distal end surface 8 a of the rotating cam 8, the protrusion 15 formed on the locking portion 7 of the rotating cam 8 cannot be engaged with the concave groove 14 of the tail plug 11. Since the tail plug 11 and the rotation suppressing member 16 are in contact with each other, the ballpoint pen refill 6 can also be rotated through the tail plug 11 as the rotary cam 8 rotates. Although not shown, a protrusion capable of engaging with the concave groove 14 of the tail plug 11 may be provided on the rotation suppressing member 16 so that the ballpoint pen refill 6 rotates reliably as the rotating cam 8 rotates. When the rotary cam 8 is rotated by a knocking operation on the knock body 4, the peripheral side surface 16 a of the rotation suppressing member 16 is in contact with the inner wall surface of the shaft cylinder 2, and this acts as a resistance to rotate the rotary cam 8. Power and rotation speed are weakened.

  In the second embodiment shown in FIG. 2, in the knock ballpoint pen 1, a rotation suppression member 19 made of nitrile rubber formed in a U-shape is bonded to the tip surface 8a of the rotation cam 8, and the rotation suppression member The rear end portion 6 a of the ballpoint pen refill 6 and the tail plug 11 are inserted into the concave portion 20 of the nineteen, and the rotation suppressing member 19 is contacted with the peripheral side surface 6aa of the rear end portion 6 a of the ballpoint pen refill 6 and the peripheral side surface 11 a of the tail plug 11. Further, the peripheral side surface 19 a of the rotation suppressing member 19 is provided in contact with the inner wall surface of the shaft tube 2. The rotation suppression member 19 is provided with an air passage hole 21 as in the rotation suppression member 16 of the knock ballpoint pen 1 of the first embodiment. The space portion 12 of the ballpoint pen refill 6 communicates with the outside of the shaft cylinder 2 through the air vent hole 13 and the concave groove 14 of the tail plug 11, the air passage hole 21 of the rotation suppressing member 19, and the through space portion 18 of the rotating cam 8. .

  In the ballpoint pen refill 6, the rotation suppression member 19 abuts on the circumferential side surface 6aa of the rear end portion 6 a of the ballpoint pen refill 6 and the circumferential side surface 11 a of the tail plug 11, so that the ballpoint pen refill 6 can also rotate as the rotary cam 8 rotates. Become. Although not shown, a protrusion that can be engaged with the concave groove 14 of the tail plug 11 is provided on the bottom surface 20 a of the concave portion 20 of the rotation suppressing member 19 so that the ball-point pen refill 6 rotates reliably as the rotary cam 8 rotates. Anyway. When the rotary cam 8 is rotated by a knocking operation on the knock body 4, the peripheral side surface 19 a of the rotation suppressing member 19 is in contact with the inner wall surface of the shaft cylinder 2, and this acts as a resistance to rotate the rotary cam 8. Power and rotation speed are weakened.

  In the third embodiment shown in FIG. 3, the tail plug 11 inserted into the rear end 6a of the ballpoint pen refill 6 in the knock type ballpoint pen 1 of the first embodiment is formed of nitrile rubber, and the rear end of the ballpoint pen refill 6 is formed. The peripheral side surface 22aa of the portion 22a protruding from the end is provided so as to contact the inner wall surface of the shaft tube 2, and the tail plug is used as the rotation suppressing member 22. The rotation suppressing member 22 is provided with an air vent hole 23 in the same manner as the tail plug 11 of the knock type ballpoint pen 1 of the above embodiment, and a concave groove 24 connected to the air vent hole 23 on the rear end surface 22b of the rotation suppressing member 22. Is provided. Similar to the tail plug of the conventional knock type ballpoint pen, the space portion 12 of the ballpoint pen refill 6 communicates with the outside of the shaft cylinder 2 through the air vent hole 23 and the concave groove 24 of the rotation suppressing member 22 and the through space portion 18 of the rotation cam 8. is doing.

  A protrusion 25 that can be engaged with the groove 24 is provided on the distal end surface 8 a of the rotating cam 8, and the protrusion 25 is engaged with the groove 24. As the rotary cam 8 rotates, the ballpoint pen refill 6 can also rotate in conjunction with the rotation suppressing member 22. When the rotary cam 8 is rotated by a knocking operation on the knock body 4, the peripheral side surface 22aa of the rotation suppressing member 22 is in contact with the inner wall surface of the shaft cylinder 2, and this acts as a resistance to rotate the rotary cam 8. Power and rotation speed are weakened.

  The fourth embodiment shown in FIG. 4 is the knock type ballpoint pen 1 in the first embodiment, with the tip of the rotating cam 8 in a state where the ballpoint pen tip (not shown) of the ballpoint pen refill 6 is immersed in the shaft cylinder 2. The surface 8a is located behind the tip 10a of the projecting piece 10 constituting the cam groove 3, and in a conventional knock type ballpoint pen, a rotation suppressing member 26 made of nitrile rubber is fixed to the outer peripheral surface of the ballpoint pen refill 6, A circumferential side surface 26 a of the rotation suppressing member 26 is provided in contact with the inner wall surface of the shaft tube 2. The rear end surface 11 a of the tail plug 11 is provided with a concave groove 14 connected to the air vent hole 13, and the space 12 of the ballpoint pen refill 6 is a space through which the air vent hole 13 and the concave groove 14 of the tail plug 11 and the rotary cam 8 pass. The portion 18 communicates with the outside of the shaft cylinder 2. Further, the projection 15 formed on the locking portion 7 of the rotary cam 8 engages with the concave groove 14 of the tail plug 11, so that the ballpoint pen refill 6 can be rotated in conjunction with the rotation of the rotary cam 8. .

  When the rotary cam 8 is rotated by the knocking operation to the knock body 4, the peripheral side surface 26 a of the rotation suppressing member 26 is in contact with the inner wall surface of the shaft cylinder 2, and this acts as a resistance to rotate the rotary cam 8. Power and rotation speed are weakened.

  The present invention has a knock type feeding mechanism composed of a cam groove, a rotating cam, a fixed cam and a knock body arranged in a shaft cylinder, and contains a knock type writing instrument such as a ballpoint pen and a marker, a correction fluid, and the like. It can be used to reduce the knocking sound generated during the knocking operation in an application tool, a knock-type cosmetic tool containing a cosmetic liquid, or a drawing tool having a solid core for drawing or the like.

The first embodiment of the present invention has a feeding structure in which the tip surface of the rotating cam is located in front of the tip of the projecting piece constituting the cam groove when the writing tip of the writing body is immersed in the shaft cylinder. It is a longitudinal cross-sectional view of the feeding mechanism part of a knock type ball-point pen. In a state in which the writing tip portion of the writing body is immersed in the shaft cylinder, the feeding structure in which the tip surface of the rotating cam is positioned in front of the tip of the projecting piece constituting the cam groove is shown. It is a longitudinal cross-sectional view of the feeding mechanism part of the knock type ball-point pen which has. In a third embodiment of the present invention, there is a payout structure in which the tip surface of the rotating cam is positioned in front of the tip of the projecting piece constituting the cam groove in the state where the writing tip of the writing body is immersed in the shaft tube. It is a longitudinal cross-sectional view of the feeding mechanism part of a knock type ball-point pen. In the fourth embodiment of the present invention, the writing cam has a feeding structure in which the tip end surface of the rotating cam is positioned behind the tip of the projecting piece constituting the cam groove in a state where the writing tip of the writing body is immersed in the shaft tube. It is a longitudinal cross-sectional view of the feeding mechanism part of a knock type ball-point pen. In a conventional knock-type ballpoint pen, a longitudinal sectional view of a portion of the feeding structure in which the tip surface of the rotating cam is positioned in front of the tip of the projecting piece constituting the cam groove when the writing tip of the writing body is immersed in the shaft cylinder It is. In a conventional knock-type ballpoint pen, a longitudinal sectional view of a portion of the feeding structure in which the tip surface of the rotating cam is located behind the tip of the projecting piece constituting the cam groove when the writing tip of the writing body is immersed in the shaft cylinder It is. It is a side view of a general fixed cam. It is a side view of a general rotation cam. It is the conceptual diagram which showed the positional relationship of the cam groove in a knock type writing instrument, the uneven | corrugated | grooved part and protrusion of a fixed cam, the meshing part of a rotation cam, and a cam protrusion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Knock-type ball-point pen 2 Shaft cylinder 3 Cam groove 4 Knock body 5 Fixed cam part 6 Ball-point pen refill 8 Rotation cam 16, 19, 22, 26 Rotation suppression member

Claims (1)

  A writing tip of a writing body that is urged backward by a spring in a shaft cylinder and is movably moved back and forth, has a cam groove and a projection engaging with the cam groove on the peripheral side, and an uneven portion at the tip. A fixed cam provided to be movable back and forth along the cam groove having a cam groove, and a front end having a meshing portion that has a cam projection that engages with the cam groove on the circumferential side portion and meshes with the uneven portion. Writing by means of a knock-type feeding mechanism composed of a rotating cam that comes into contact with the rear end portion, is connected to the fixed cam at the rear end and is movable back and forth along the cam groove, and a knock body for pressing the fixed cam In a knock-type writing instrument in which the body rotates with the rotation of the rotating cam and protrudes and retracts from the opening at the tip of the shaft cylinder, the rotating cam is rotated so that at least a part thereof is in contact with the inner wall surface of the shaft cylinder. At least partly on the circumferential side of the cursive body and / or intervening suppression members The rotation restriction member provided so as to contact the inner wall surface of the barrel, knock-type writing instrument, characterized in that weakened the rotational force and rotation speed of the rotary cam during knocking operation.

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