JP2023158871A - Knock-type writing instrument - Google Patents

Abstract

To provide a knock-type writing instrument which reduces the occurrence of a locking sound of a rotating member during a knock operation and does not cause the feeling of a knock operation to become heavy.SOLUTION: The retractable mechanism includes a cam portion 5 formed inside a barrel 2, a rotating member 6 that engages with the cam portion 5 and supports the rear end of a writing body 9, an operating portion 7 provided with cam teeth 81 that impart rotation to the rotating member 6, and an elastic body that is housed in the barrel 2 and urges the writing body 9 backward. A plurality of outward protrusions 61 are formed in a distributed manner on the outer peripheral surface of the rotating member 6. A plurality of inward protrusions 21 are formed in a distributed manner on the inner peripheral surface of the shaft barrel 2. The outward protrusions 61 on the outer peripheral surface of the rotating member 6 and the inward protrusions 21 on the inner peripheral surface of the barrel 2 come into sliding contact in the circumferential direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a knock-type writing instrument. In particular, the present invention relates to a knock-type writing instrument in which a writing body is housed in a barrel so as to be movable in the front-rear direction, and the nib of the writing body is configured to be retractable from a front end hole of the barrel.

Conventionally, Patent Document 1 discloses a rotor that moves forward and rotates to be locked by a pressing operation on a knocking body, and a rotor that is connected to the rotor in order to suppress the generation of sound when the rotor is locked. A structure is disclosed in which a sliding protrusion is provided on the outer circumferential surface of the central core receiver, and the sliding protrusion slides on the inner circumferential surface of the shaft cylinder.

Japanese Patent Application Publication No. 2018-144421

The configuration of Patent Document 1 is such that the sliding protrusion and the inner surface of the shaft cylinder are always in sliding contact in the circumferential direction and the axial direction, so even though the rotational speed of the rotor (corresponding to the rotating member of the present application) can be suppressed, A large pressing force is required to rotate the rotor, and the knocking operation may feel heavy.

The present invention solves the above-mentioned conventional problems, and aims to provide a knock-type writing instrument that reduces the occurrence of the locking sound of the rotating member during knock operation, and does not cause the feeling of heavy knock operation. It is something to do.
In the present invention, "front" refers to the pen tip side, and "rear" refers to the opposite side. In the present invention, the "pen tip recessed state" refers to a state in which the pen tip is retracted into the barrel. In the present invention, the "pen tip protruding state" refers to a state in which the pen tip protrudes outside from the front end hole of the barrel.

A first invention of the present application is a knock-type writing instrument, in which a writing body is housed in a barrel so as to be movable in the front-back direction, and a pen tip of the writing body is configured to be retractable from a front end hole of the barrel, An operating portion is provided on a side wall of the barrel or a rear end of the barrel, and the pen tip is made to protrude from the front end hole of the barrel by pressing the operating portion forward from a retracted state of the pen tip, The pen tip is provided with a protruding and retracting mechanism that changes the pen tip to a retracted state by pressing the operating part forward from the pen tip protruding state, and the protruding and retracting mechanism includes a cam part formed inside the barrel, and the cam part. a rotating member that engages with and supports the rear end of the writing body; and a rotating member that is provided with cam teeth that impart rotation to the rotating member; an elastic body for urging, an outward protrusion being formed on the outer circumferential surface of the rotating member, an inward protrusion being formed on the inner circumferential surface of the shaft cylinder, and an outward protrusion on the outer circumferential surface of the rotating member and the shaft It is required that the inward protrusion on the inner circumferential surface of the cylinder makes sliding contact in the circumferential direction.

As a result, in the knock-type writing instrument of the first invention, the rotating member and the inner circumferential surface of the barrel do not always make strong contact, and when the rotating member rotates, the outward protrusion on the outer circumferential surface of the rotating member and the inner circumferential surface of the barrel The inward protrusion on the circumferential surface slides into contact with the rotating member in the circumferential direction to suppress the rotational speed of the rotating member, reducing the locking sound of the rotating member during knocking without making the knock operation feel heavy. can.

A second invention of the present application is the knock-type writing instrument according to the first invention, wherein the inward protrusion is in sliding contact with the outward protrusion in the circumferential direction during the transition from the pen tip retracted state to the pen tip protruded state. The present invention is required to include a protrusion and a second inward protrusion that slides into circumferential direction with the outward protrusion during the transition from the pen tip protruding state to the pen tip retracted state.

Thereby, in the knock-type writing instrument of the second invention, the rotational speed of the rotating member is adjusted in the process of transitioning from the pen tip recessed state to the pen tip protruding state and in the process of transitioning from the pen nib protruding state to the pen tip retracted state. Therefore, it is possible to reliably reduce the occurrence of the locking sound of the rotating member during the knock operation.

A third invention of the present application is the knock-type writing instrument according to the first invention, wherein a plurality of the outward protrusions are distributed and formed on the outer circumferential surface of the rotary member, and a plurality of the inward protrusions are formed on the inner circumferential surface of the barrel. The diameter of the virtual circumscribed circle that is formed in a distributed manner and touches each of the outward protrusions is greater than or equal to the diameter of the virtual inscribed circle that touches each of the inwardly directed protrusions, and the diameter of the virtual circumscribed circle that touches each of the outward protrusions. is smaller than the inner diameter of the inner circumferential surface of the shaft cylinder between each of the inwardly directed protrusions, and the diameter of the virtual inscribed circle in contact with each of the inwardly directed protrusions is the outer circumferential surface of the rotating member between each of the outwardly directed protrusions. The outer diameter of the

Thereby, in the knock-type writing instrument of the third invention, the outward protrusion of the rotating member and the inward protrusion on the inner circumferential surface of the barrel reliably make sliding contact, and the outward protrusion of the rotating member and the inward protrusion on the inner circumferential surface of the barrel The outer circumferential surface of the rotating member and the inner circumferential surface of the shaft cylinder do not make strong sliding contact except when they are in sliding contact with each other, and it is possible to reliably prevent the knocking operation from becoming heavy.

The knock-type writing instrument of the present invention reduces the occurrence of the locking sound of the rotating member during a knock operation, and there is no risk of making the knock operation feel heavy.

FIG. 3 is a vertical cross-sectional view of a main part of the embodiment of the present invention when the pen tip is retracted. FIG. 2 is a vertical cross-sectional view of the main part of FIG. 1 when the pen tip is protruding. FIG. 2 is a vertical cross-sectional view of a main part of the barrel shown in FIG. 1; 4 is a sectional view taken along the line CC in FIG. 3. FIG. FIG. 2 is a front view of the rotating member of FIG. 1; FIG. 2 is a perspective view of the rotating member of FIG. 1; FIG. 2 is a front view of the cylindrical body of FIG. 1; FIG. 2 is a perspective view of the cylindrical body of FIG. 1; FIG. 6 is a conceptual diagram showing the development of the cam part in a state where the pen tip is retracted. 10 is a sectional view taken along the line AA in FIG. 1 showing the state in FIG. 9 (however, the clip body is omitted). FIG. 10 is an exploded conceptual diagram of the cam section showing a state in which the operating section is knocked from the pen tip recessed state in FIG. 9. FIG. 12 is a sectional view taken along the line BB in FIG. 2 showing the state in FIG. 11 (however, the clip body is omitted). FIG. 12 is an exploded conceptual diagram showing a process of engagement between the rotating member and the cam portion from the state shown in FIG. 11; 14 is a sectional view taken along line BB in FIG. 2 showing the state in FIG. 13 (however, the clip body is omitted). FIG. FIG. 14 is an exploded conceptual diagram showing a process of engagement between the rotating member and the cam portion from the state shown in FIG. 13; 16 is a sectional view taken along line BB in FIG. 2 showing the state in FIG. 15 (however, the clip body is omitted). FIG. FIG. 16 is an exploded conceptual diagram showing a locked state (pen tip protruding state) between the rotating member and the cam part from the state shown in FIG. 15; 18 is a sectional view taken along the line BB in FIG. 2 showing the state in FIG. 17 (however, the clip body is omitted). FIG. 18 is an exploded conceptual diagram showing a process of disengaging the rotating member and the cam portion from the state of FIG. 17 (pen tip protruding state). FIG. 20 is a sectional view taken along the line BB in FIG. 2 showing the state in FIG. 19 (however, the clip body is omitted).

A knock-type writing instrument 1 according to an embodiment of the present invention is shown in FIGS. 1 to 20.

The knock type writing instrument 1 of this embodiment includes a barrel 2, a writing body 9 housed in the barrel 2, and a pen tip of the writing body 9 inserted through a front end hole (not shown) of the barrel 2. It is provided with a retractable mechanism that can freely retract and retract, and a clip body as an operating section 7 of the retractable mechanism.

- Cursive body The cursive body 9 includes a pen nib (not shown), an ink storage tube 91 in which the pen nib is press-fitted into the front end opening, ink filled in the ink storage tube 91, and It consists of a follower (for example, a high viscosity fluid) that is filled at the rear end of the ink and moves forward as the ink is consumed. A tail plug 92 is attached to the rear end opening of the ink storage tube 91 and is provided with a vent hole that allows ventilation between the ink storage tube 91 and the outside.

For example, the pen tip may be composed of only a metal ballpoint pen tip rotatably holding a ball at the front end, or a synthetic resin pen tip holder that holds the rear outer surface of the ballpoint pen tip. There may be. A spring that presses the ball at the front end forward is housed inside the pen tip. The spring includes a rod portion at the front end of a compression coil spring, and the front end of the rod portion is in contact with the rear surface of the ball. When not writing, the forward bias of the spring brings the ball into close contact with the inner surface of the inward front edge of the front end of the ballpoint pen tip, thereby preventing ink leakage and evaporation from the front end of the pen tip.

- Shaft cylinder The shaft cylinder 2 includes a tapered cylindrical front shaft (not shown), a cylindrical intermediate shaft 3 connected to the rear end of the front shaft, and a rear end of the intermediate shaft 3. It consists of a cylindrical rear shaft 4 that is connected.

- Intermediate shaft The intermediate shaft 3 is made of a cylindrical molded body of synthetic resin (for example, polycarbonate resin). A female thread is formed on the inner surface of the front end of the intermediate shaft 3. The male threaded portion of the front shaft can be screwed into the female threaded portion. A reduced diameter portion is integrally formed at the rear end portion of the intermediate shaft 3. A first elongated hole extending in the front-rear direction is formed in the side wall of the rear end of the intermediate shaft 3 and has a closed front end and an open rear end. Further, a guide groove extending in the front-rear direction is formed on the outer surface of the intermediate shaft 3 in front of the first elongated hole. The ball portion of the clip body 7 is always engaged with the guide groove, and as the clip body 7 moves in the front-back direction, the ball portion of the clip body 7 is movable in the front-rear direction along the guide groove. . An object to be held, such as a pocket, is firmly held by the guide groove and the ball portion.

- Cam portion As shown in FIG. 3, a cam portion 5 is integrally formed on the inner circumferential surface of the intermediate shaft 3 in front of the reduced diameter portion. The cam portion 5 includes a plurality (for example, four) of serrated cam teeth 51 that protrude forward and radially inward, and a plurality (for example, four) of serrated cam teeth 51 that extend in the front-rear direction and are formed between the cam teeth 51. cam groove 52. The cam teeth 51 of the cam portion 5 include a first cam slope 51a, a second cam slope 51b, and a locking surface 51c formed between the first cam slope 51a and the second cam slope 51b. The locking surface 51c consists of a surface extending in the axial direction. A concave groove 53 extending in the axial direction is formed in the cam tooth 51 between each first cam slope 51b and the locking surface 51c. The concave groove 53 has a shallower depth than the cam groove 52. That is, the bottom surface of the concave groove 53 is located radially inward from the bottom surface of the cam groove 52. In this embodiment, the cam part 5 is formed integrally with the inner circumferential surface of the member (for example, the intermediate shaft 3) constituting the shaft cylinder 2, but in addition to this, a separate member having the cam part is formed. The structure may be such that it is attached to the inner circumferential surface of the shaft cylinder 2.

One end of the first cam slope 51a is connected to the cam groove 52. The first cam slope 51a and the cam groove 52 form an acute angle. The other end of the first cam slope 51a is connected to the rear end of the locking surface 51c. The first cam slope 51a and the locking surface 51c form an acute angle. One end of the second cam slope 51b is connected to the front end of the locking surface 51c. The second cam slope 51b and the locking surface 51c form an acute angle. The other end of the second cam slope 51b is connected to the cam groove 52. The second cam slope 51b and the cam groove 52 form an obtuse angle.

・Inward protrusion (first inward protrusion, second inward protrusion)
A plurality of inward protrusions 21 are integrally formed on the inner peripheral surface of the shaft cylinder 2 (inner peripheral surface of the intermediate shaft 3) in front of the cam portion 5. Specifically, the first inward protrusion 21a is integrally formed in a virtual extension region extending axially forward from each first cam slope 51a on the inner circumferential surface of the shaft cylinder 2 (inner circumferential surface of the intermediate shaft 3). . Further, on the inner circumferential surface of the shaft cylinder 2 (inner circumferential surface of the intermediate shaft 3), a virtual extension area extending axially forward from the cam groove 52 side of each second cam slope 51b or a second cam of each cam groove 52 is provided. The second inward protrusion 21b is integrally formed in a virtual extension region extending axially forward from the slope 51b side.

The first inward protrusion 21a and the second inward protrusion 21b are composed of ribs extending in the axial direction. The first inward protrusions 21a and the second inward protrusions 21b are circumferentially positioned at equal intervals and alternately. Four first inward protrusions 21a are formed in a distributed manner. Four second inward protrusions 21b are formed in a distributed manner. That is, a total of eight inward protrusions 21 are formed in a distributed manner.

The outer surface of the first inward protrusion 21 a and the outer surface of the second inward protrusion 21 b have a convex curved cross section. Smooth sliding contact is possible.

- Rear shaft The rear shaft 4 is made of a cylindrical molded body of synthetic resin (for example, polycarbonate resin). A second elongated hole extending in the front-rear direction is formed in the side wall of the front end of the rear shaft 4 and is open at the front end and closed at the rear end.

-Rotating member The rotating member 6 is shown in FIGS. 5 and 6. The rotating member 6 is integrally formed with a plurality of (for example, four) protrusions 61 extending in the front-rear direction at equal intervals on its outer peripheral surface. A cam slope 61a is formed at the rear end of each protrusion 61. The protrusion 61 is engaged with the cam teeth 51 of the cam portion 5 and the cam groove 52 of the cam portion 5. On the outer peripheral surface of the rotating member 6 in front of the protrusion 61, outward protrusions 62 consisting of a plurality of (for example, four) ribs extending in the axial direction are integrally formed at equal intervals. The outward protrusion 62 is formed on an imaginary extension line extending axially forward from the protrusion 61 . The diameter D of the virtual circumscribed circle that contacts the radial top of each outward protrusion 62 is set larger than the diameter H of the virtual circumscribed circle that contacts the radial top of each protrusion 61 . Thereby, even if the inward protrusion 21 protrudes by a small amount in the radial direction, reliable sliding contact between the inward protrusion 21 and the outward protrusion 62 is possible.
In this embodiment, the outward protrusion 62 is formed integrally with the outer circumferential surface of the rotating member 6, but other than this, a separate member having the outward protrusion 62 may be attached to the rotating member 6. .

The outer surface of each of the outward protrusions 62 has a convexly curved cross section, thereby allowing smooth sliding contact with the inward protrusion 21 on the inner peripheral surface of the shaft cylinder 2. An inner hole penetrating in the front-rear direction is formed inside the rotating member 6. The rotating member 6 is obtained from a molded body of synthetic resin (for example, polyacetal resin).

As shown in FIG. 10, the diameter D of the virtual circumscribed circle in contact with each of the outward projections 62 is greater than or equal to the diameter F of the virtual inscribed circle in contact with each of the inward projections 21 (preferably, each of the outward projections 62 The diameter D of the virtual circumscribed circle in contact with is larger than the diameter F of the virtual inscribed circle in contact with each of the inward protrusions 21). The diameter D of the virtual circumscribed circle in contact with each of the outward protrusions 62 is smaller than the inner diameter E of the inner peripheral surface of the shaft cylinder 2 between the respective inward protrusions 21 . The diameter F of the virtual inscribed circle in contact with each of the inward projections 21 is larger than the outer diameter G of the outer peripheral surface of the rotating member 6 between the respective outward projections 62.

- Clip body As shown in FIGS. 1 and 2, the clip body 7 (operation section) includes a clip body 71 extending in the front-rear direction, a base 72 integrally connected to the rear of the clip body 71, and It includes a shaft portion 73 that is integrally connected to the base portion 72 and extends forward from the base portion 72 . Further, the clip body 7 includes a cylindrical body 8 attached to the outer peripheral surface of the shaft portion 73. The clip body 7 is obtained from a molded body of synthetic resin (for example, polycarbonate resin). A plate-shaped ball portion is integrally provided on the back surface (inner surface) of the clip body 71 in a protruding manner.

- Cylindrical body Figures 7 and 8 show the cylindrical body 8. Cam teeth 81 having V-shaped cam slopes are integrally formed around the front end of the cylindrical body 8 . An inner hole passes through the inside of the cylindrical body 8 in the front-rear direction. The clip body 7 and the cylindrical body 8 are integrally movable in the front-back direction. A plurality of guide protrusions 82 are integrally formed on the outer peripheral surface of the cylindrical body 8, and the guide protrusions 82 engage movably in the front-rear direction along the cam groove 52 and the groove 53 of the cam portion 5. , thereby preventing rotation of the cylindrical body 8 within the shaft tube 2. The cylindrical body 8 is obtained by molding a synthetic resin (for example, polyacetal resin). In this embodiment, the cam teeth 81 are formed integrally with a separate member (i.e., the cylindrical body 8) that is attached to the clip body 7. ) may be formed integrally with the

The intermediate shaft 3 and the rear shaft 4 are connected, and the first elongated hole and the second elongated hole form a slide hole 22 that extends in the front-rear direction. The clip body 7 (a portion of the clip body 71 and the base portion 72) protrudes radially outward from the slide hole 22, and the clip body 7 is configured to be slidable in the front-rear direction along the slide hole 22.

・Protrusion/retraction mechanism The above-mentioned ejection/retraction mechanism is a side slide type using a rotary cam mechanism, which presses forward (knocks) the clip body 7 (operation part) that protrudes radially outward from the side wall of the shaft cylinder 2. It is a haunting mechanism. The retractable mechanism includes a cam portion 5 formed on the inner circumferential surface of the intermediate shaft 3, a rotating member 6 that engages with the cam portion 5 and abuts the rear end of the writing body 9, and a rotating member 6 that engages with the rotating member 6. and a clip body 7 that projects outward in the radial direction from the slide hole 22, and an elastic body (for example, a compression coil spring, not shown) that is housed in the barrel 2 and biases the writing body 9 backward. Become. The ejection/retraction mechanism of this embodiment is a double-knock type in which the clip body 7 (operation section) is slid forward for both the operation of protruding the pen tip and the operation of retracting the pen tip. In addition to the side slide type, the present invention may be of a rear end knock type in which an operating portion protruding from the rear end hole of the shaft tube 2 is pressed forward (knock operation).

The cam portion 5 includes a plurality (for example, four) of serrated cam teeth 51 that protrude forward and radially inward, and a plurality (for example, four) of serrated cam teeth 51 that extend in the front-rear direction and are formed between the cam teeth 51. cam groove 52. The rotating member 6 includes a plurality of (for example, four) protrusions 61 extending in the longitudinal direction on its outer peripheral surface. The protrusion 61 of the rotating member 6 is engaged with the cam teeth 51 of the cam portion 5 and the cam groove 52 of the cam portion 5. At the front end of the cylindrical body 8 attached to the shaft portion 73 of the clip body 7, cam teeth 81 that engage with the cam slope 61a at the rear end of the protrusion 61 of the rotating member 6 are integrally formed in a circumferential manner. .

- Protrusion of the pen tip When the clip body 7 is slid forward (knocking operation) from the pen tip retracted state against the backward bias by the projectile body, the cylindrical body 8 attached to the shaft portion 73 of the clip body 7 The rotating member 6 is pressed forward, and the protrusion 61 of the rotating member 6 moves forward along the cam groove 52. Accordingly, the rotary member 6 presses the rear end of the writing body 9 forward, and the pen tip projects outward from the front end hole. At this time, the cam teeth 81 of the cylindrical body 8 attached to the shaft part 73 come into contact with the cam slope 61a at the rear end of the protrusion 61 of the rotary member 6, so that the rotary member 6 is angled at a certain angle with respect to the cam part 5. only rotates. Thereby, the rear end portion of the protrusion 61 of the rotating member 6 is engaged with the cam teeth 51 of the cam portion 5, and the pen tip protruding state is maintained.

When the clip body 7 is slid forward (knocking operation) from the state where the pen tip is protruding against the backward bias by the resilient body, the cylindrical body 8 attached to the shaft portion 73 of the clip body 7 pushes the rotating member 6. When pressed forward, the cam teeth 81 of the cylindrical body 8 come into contact with the rear ends of the protrusions 61 of the rotary member 6, so that the rotary member 6 rotates by a certain angle with respect to the cam portion 5. As a result, the engagement between the rear end of the protrusion 61 and the cam teeth 51 of the cam portion 5 is released, and the protrusion 61 is moved along the cam groove 52 of the cam portion 5 due to the backward bias by the resilient body. move backwards. As the rotary member 6 moves rearward, the writing body 9 moves rearward and enters the pen tip recessed state.

- Functions of the inwardly directed projections and outwardly directed projections Next, the actions of the inwardly directed projections 21 and the outwardly directed projections 62 will be explained in order. In Figures 9, 11, 13, 15, 17, and 19, the lower side is the front (pen tip side)

FIGS. 9 and 10 show the pen tip recessed state. In this state, the protrusion 61 of the rotating member 6 is engaged with the cam groove 52. Further, in this state, the outward protrusion 62 of the rotating member 6 is located at the rear of the first inward protrusion 21a and the second inward protrusion 21b.

11 and 12 show a state in which the operating portion 7 is pressed forward from the pen tip retracted state (FIG. 9).
As the clip body 7 moves forward, the cam teeth 81 of the cylindrical body 8 come into contact with the cam slope 61a at the rear end of the protrusion 61 of the rotating member 6, and the rotating member 6 moves forward. The engagement between the protrusion 61 and the cam groove 52 is released. In this state, the outward protrusion 62 is positioned between the first inward protrusion 21a and the second inward protrusion 21b.

13 and 14 show a state where the engagement between the rear end of the protrusion 61 of the rotating member 6 and the first cam slope 51a starts from the state shown in FIG. 11. The cam teeth 81 of the cylindrical body 8 and the cam slope 61a at the rear end of the protrusion 61 of the rotating member 6 are rotated by a certain angle, and the engagement between the rear end of the protrusion 61 and the first cam slope 51a is prevented. will be started. As the engagement between the rear end of the protrusion 61 and the first cam slope 51a progresses, the outward protrusion 62 approaches the first inward protrusion 21a from the circumferential direction.

15 and 16, the engagement between the rear end of the protrusion 61 of the rotating member 6 and the first cam slope 51a progresses from the state shown in FIG. 1 shows a state in which the inward protrusions 21a are in sliding contact with each other in the circumferential direction. At this time, the outward protrusion 62 and the first inward protrusion 21a are elastically deformed in the radial direction.

17 and 18, the engagement between the rear end of the protrusion 61 of the rotating member 6 and the first cam slope 51a progresses from the state shown in FIG. This shows a state in which the pen tip is engaged with the engagement surface 51c (pen tip protruding state). Immediately before the rear end of the protrusion 61 and the locking surface 51c are locked, the outward projection 62 and the first inward projection 21a come into sliding contact in the circumferential direction, thereby temporarily reducing the rotational speed of the rotating member 6. However, the collision between the locking surface 51c and the protrusion 61 is weakened, and the generation of locking noise is suppressed.

19 and 20 show that after the engagement between the rear end of the protrusion 61 of the rotating member 6 and the locking surface 51c is released from the state shown in FIG. This shows a state in which engagement with the two-cam slope 51b has progressed. From this state, as the engagement between the rear end of the protrusion 61 of the rotating member 6 and the second cam slope 51b progresses, the outward protrusion 62 and the second inward protrusion 21b elastically deform each other in the radial direction. The outward protrusion 62 of the rotating member 6 and the second inward protrusion 21b on the inner surface of the shaft cylinder 2 are in sliding contact with each other in the circumferential direction. Thereafter, the cam groove 52 and the protrusion 61 are in a locked state (the pen tip retracted state in FIG. 9). Immediately before the cam groove 52 and the rear end of the protrusion 61 are engaged, the outward projection 62 and the second inward projection 21b come into sliding contact in the circumferential direction, so that the rotational speed of the rotating member 6 is temporarily reduced. , the collision between the cam groove 52 and the protrusion 61 is weakened, and the occurrence of locking noise is suppressed.

In this embodiment, the inward protrusions 21 (the first inward protrusions 21 a and the second inward protrusions 21 b ) are formed at equal intervals on the inner circumferential surface of the shaft cylinder 2 , and the outward protrusions 62 are formed on the outer circumferential surface of the rotating member 6 . They are formed at equal intervals. Thereby, each inward protrusion 21 and each outward protrusion 62 are brought into sliding contact at the same time, and the rotational speed of the rotating member 6 can be effectively suppressed. In addition to this, the present invention may be configured such that at least a plurality of either the outward protrusions 62 or the inward protrusions 21 are formed; for example, a single outward protrusion 62 is formed on the outer peripheral surface of the rotating member 6, and A configuration in which a plurality of inward protrusions 21 are formed on the inner circumferential surface of the shaft cylinder 2, or a single inward protrusion 21 is formed on the inner circumferential surface of the shaft cylinder 2 and a plurality of outward protrusions 62 are formed on the outer circumference of the rotating member 6. An example is a structure formed on a surface.

In this embodiment, the outward protrusion 62 and the inward protrusion 21 (the first inward protrusion 21a and the second inward protrusion 21b) are formed by ribs extending in the axial direction. As a result, in the process of protruding and retracting the pen tip (the process of engagement between the cam portion 5 and the protrusion 61), despite the configuration in which the rotating member 6 rotates while moving backward, the outward protrusion 62 and the inward protrusion 21 (the first inward protrusion Stable sliding contact with the protrusion 21a and the second inward protrusion 21b is possible.

The knock-type writing instrument 1 of the present embodiment accommodates a writing body 9 in a barrel 2 so as to be movable in the front-back direction, and the pen tip of the writing body 9 is configured to be retractable from the front end hole of the barrel 2. This is a knock-type writing instrument, in which an operating part 7 is provided on the side wall of the barrel 2, and by pressing the operating part 7 forward from the pen tip recessed state, the pen tip can be moved from the front end hole of the barrel 2. The projecting mechanism includes a retracting mechanism that causes the pen tip to be in a retracted state by bringing the pen tip into a protruding state and pressing the operating portion 7 forward from the pen tip protruding state, and the retracting mechanism is a cam formed inside the shaft tube 2. part 5, a rotating member 6 that engages with the cam part 5 and supports the rear end of the writing body 9, and the operating part 7, which includes cam teeth 81 that impart rotation to the rotating member 6; an elastic body that is housed in the barrel 2 and urges the writing body 9 backward; an outward protrusion 62 is formed on the outer peripheral surface of the rotary member 6; An inward protrusion 21 is formed, and an outward protrusion 62 on the outer circumferential surface of the rotating member 6 and an inward protrusion 21 on the inner circumferential surface of the shaft cylinder 2 are in sliding contact in the circumferential direction. As a result, in the knock-type writing instrument 1 of the present embodiment, the rotating member 6 and the inner circumferential surface of the shaft tube 2 do not always make strong contact, and when the rotating member 6 rotates, the outward protrusion 62 on the outer circumferential surface of the rotating member 6 The rotational speed of the rotating member 6 can be suppressed by sliding contact with the inward protrusion 21 on the inner circumferential surface of the shaft cylinder 2 in the circumferential direction, and the rotating member 6 can be locked during the knocking operation without making the knocking operation feel heavy. Sound generation can be reduced.

The knock-type writing instrument 1 of the present embodiment has a first inward protrusion 21a that slides in circumferential direction with the outward protrusion 62 in the process of transitioning from the pen tip retracted state to the pen tip protruded state, and a pen nib. This configuration includes a second inward protrusion 21b that comes into sliding contact with the outward protrusion 62 in the circumferential direction during the transition from the protruding state to the retracted pen tip state. As a result, in the knock-type writing instrument 1 of the present embodiment, the rotation of the rotating member 6 occurs in the process of transitioning from the pen tip recessed state to the pen tip protruding state and in the process of transitioning from the pen nib protruding state to the pen tip retracted state. The speed can be suppressed, and the generation of the locking sound of the rotating member 6 during the knocking operation can be reliably reduced.

The knock-type writing instrument 1 of the present embodiment has a plurality of outward protrusions 62 distributed on the outer circumferential surface of the rotary member 6, and a plurality of inward protrusions 21 dispersed on the inner circumferential surface of the barrel 2. and the diameter D of the virtual circumscribed circle in contact with each of the outward protrusions 62 is greater than or equal to the diameter F of the virtual inscribed circle in contact with each of the inward protrusions 21, and The diameter D is smaller than the inner diameter E of the inner peripheral surface of the shaft cylinder 2 between the respective inward protrusions 21, and the diameter F of the virtual inscribed circle touching each of the inward protrusions is the outer protrusion 62. is required to be larger than the outer diameter G of the outer circumferential surface of the rotating member 6 between them.

Thereby, in the knock-type writing instrument of the third invention, the outward protrusion 62 of the rotating member 6 and the inward protrusion 21 on the inner circumferential surface of the barrel barrel 2 reliably come into sliding contact, and the outward protrusion 62 of the rotating member 6 and the barrel barrel The rotating member 6 and the inner circumferential surface of the shaft cylinder 2 do not make strong sliding contact except when the inwardly directed protrusion 21 on the inner circumferential surface of the rotary member 6 makes sliding contact, and it is possible to reliably prevent the knocking operation feeling from becoming heavy.

1 Knock type writing instrument 2 Shaft tube 21 Inward protrusion 21a First inward protrusion 21b Second inward protrusion 22 Slide hole 3 Intermediate shaft 4 Rear shaft 5 Cam part 51 Cam tooth 51a First cam slope 51b Second cam slope 51c Locking surface 52 Cam groove 53 Concave groove 6 Rotating member 61 Projection 61a Cam slope 62 Outward protrusion 7 Operation section (clip body)
71 Clip body 72 Base 73 Shaft 8 Cylindrical body 81 Cam teeth 82 Guide protrusion 9 Writing body 91 Ink storage tube 92 Tail plug

Claims (3)

A knock-type writing instrument in which a writing body is housed in a barrel so as to be movable in the front and back direction, and a pen tip of the writing body is configured to be retractable from a front end hole of the barrel,
An operating portion is provided on a side wall of the barrel or a rear end of the barrel, and the pen tip is made to protrude from the front end hole of the barrel by pressing the operating portion forward from a retracted state of the pen tip, comprising a retracting mechanism that causes the pen tip to be in a retracted state by pressing the operating portion forward from the pen tip protruding state;
The protruding and retracting mechanism includes a cam portion formed inside the shaft cylinder;
a rotating member that engages with the cam portion and supports the rear end of the writing body;
the operating section including cam teeth that impart rotation to the rotating member;
an elastic body that is housed in the barrel and urges the writing body backward;
An outward protrusion is formed on the outer peripheral surface of the rotating member, and an inward protrusion is formed on the inner peripheral surface of the shaft cylinder,
A knock-type writing instrument characterized in that an outward protrusion on the outer circumferential surface of the rotating member and an inward protrusion on the inner circumferential surface of the barrel are in sliding contact in the circumferential direction. The inward protrusion has a first inward protrusion that slides in circumferential direction with the outward protrusion in the process of transitioning from the pen tip retracted state to the pen tip protruding state, and a first inward protrusion that slides in circumferential direction with the outward protrusion in the process of transitioning from the pen tip retracted state to the pen nib protruding state, and The knock-type writing instrument according to claim 1, further comprising a second inward protrusion that makes sliding contact with the protrusion in the circumferential direction. A plurality of the outward protrusions are formed dispersedly on the outer circumferential surface of the rotating member, a plurality of the inward protrusions are formed dispersedly on the inner circumferential surface of the shaft cylinder, and the diameter of a virtual circumscribed circle in contact with each of the outward protrusions is , the diameter of the imaginary inscribed circle that contacts each of the inwardly directed protrusions is greater than or equal to the diameter of the imaginary inscribed circle that contacts each of the inwardly directed protrusions, and the diameter of the imaginary circumscribed circle that contacts each of the inwardly directed protrusions is greater than the inner diameter of the inner circumferential surface of the shaft cylinder between each of the inwardly directed protrusions. 2. The knock-type writing instrument according to claim 1, which is small and has a diameter of an imaginary inscribed circle in contact with each of the inward protrusions that is larger than an outer diameter of an outer circumferential surface of the rotating member between the respective outward protrusions.

Images