Retractable writing instrument

Abstract

To provide a retractable writing instrument which maintains the conventional feeling of retractable operation of a pen tip, is less likely to cause retraction operation failures, and is less prone to generate noise due to collision between a rotating member and other members during retraction operation and rattling of a clip body.SOLUTION: The present invention discloses a retractable writing instrument in which a pen tip 131 can be retracted by sliding a clip body 7 projecting from the side wall of a barrel 2 forward. The clip body 7 and a rotating member 6 are engaged with each other with some play in the front-rear direction. A second elastic body 12 is interposed between the clip body 7 and the rotating member 6. The second elastic body 12 urges the rotating member 6 forward with respect to the clip body 7. The rotating member 6 has a front locking wall portion 64 that locks the front end of the second elastic body 12. The clip body 7 has a rear locking wall portion 96 that locks the rear end of the second elastic body 12. The front locking wall portion 64 or the rear locking wall portion 96 is locked to the second elastic body 12 so as to be in slide contact therewith.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] The present invention relates to a retractable writing instrument, and more particularly to a clip-slide type retractable writing instrument in which a writing body is housed in a barrel so as to be movable in the forward and backward directions, and the pen tip of the writing body is retractable by sliding a clip body forward. [Background technology]

[0002] Patent document 1 describes a retractable writing instrument that has a slide hole extending in the front-to-rear direction on the side wall of the barrel, a clip body that protrudes radially outward from the slide hole, and is configured to be movable in the front-to-rear direction along the slide hole, and is equipped with a retractable mechanism that causes the pen tip to protrude from the front end hole of the barrel by sliding the clip body forward from a retracted pen tip state, and causes the pen tip to retract by sliding the clip body forward from the retracted pen tip state.

[0003] The retractable mechanism comprises a cam portion formed on the inner surface of the barrel, a rotating member that engages with the cam portion and abuts against the rear end of the writing body, a clip body with cam teeth that engage with the rotating member, and a spring body that is housed within the barrel and urges the writing body rearward, and the clip body and the rotating member are engaged with each other to prevent them from coming loose while having some play in the front-to-back direction.

[0004] Patent Document 2 describes a retractable writing instrument that includes a barrel, a knock body that is supported within the barrel so that it can move back and forth within a first range relative to the barrel and has its rear end exposed outside the barrel, a rotor (rotating member) that is pushed forward by the knock body, a cam mechanism that rotates and locks the rotor using cam slopes (cam teeth) when it moves forward, a core (writing body) that is connected to the front end of the rotor and causes a writing part to protrude from the front end of the barrel as the rotor moves forward, and a first biasing member (first resilient body) that biases the rotor backward relative to the barrel, whereby the knock body is connected to the rotor so that it can move slightly back and forth within a second range that is smaller than the first range, and a second biasing member (second resilient body) that biases the knock body backward relative to the barrel, thereby preventing the knock body from rattling back and forth and generating noise.

[0005] Furthermore, paragraph number 0055 of Patent Document 2 states that the load of the second urging member (second spring body) is greater than the load of the extended first urging member (first spring body) when the writing part is stored, and is less than the load of the contracted first urging member when the writing part (pen tip) is protruding. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-006315 [Patent Document 2] Japanese Patent Application Publication No. 2018-149787 Summary of the Invention [Problem to be solved by the invention]

[0007] In the retractable writing instrument disclosed in Patent Document 1, the clip body and the rotating member are locked together with some back-and-forth play. Therefore, when vibrations are applied to the writing instrument in the nib-extended state, the clip body rattles back and forth by the amount of play, generating noise. Furthermore, when switching between the retracted and extended states of the nib, the rotating member collides with the cam teeth on the clip body, or the rotating member collides with the cam portion, generating a collision noise. However, when using a retractable writing instrument in a quiet environment, there is a need to reduce the noise generated as much as possible. In particular, retractable writing instruments with a clip-slide mechanism are prone to rattle of the clip body. Furthermore, because a slide hole is provided in the side wall of the barrel, sound is emitted from the slide hole and cannot be blocked by the barrel, so further noise reduction is required.

[0008] In the retractable writing instrument disclosed in Patent Document 2, when the pen tip is retracted, the load of the second spring body is greater than the load of the first spring body, so the rotating member comes into contact with the cam teeth during the pen tip extension operation. The retractable writing instrument disclosed in Patent Document 2 may cause a user to feel uncomfortable during the retraction operation.

[0009] Furthermore, a coil spring is used as the second resilient body in Patent Document 2. In the second embodiment of Patent Document 2, the lower end of the second resilient body is locked by a rotating member, but there is a possibility that the second resilient body may get caught on the rotating member during the extending / retracting operation, hindering the proper rotation of the rotating member and preventing the pen tip from extending / retracting normally.

[0010] The present invention is intended to solve the above-mentioned problems of the prior art, and aims to provide a retractable writing instrument equipped with a retraction mechanism that retracts the pen tip by sliding the clip body forward, which maintains the feel of the conventional pen tip retraction operation, is less likely to cause malfunctions in the retraction operation, and is less likely to produce noise due to collisions between the rotating member and other members or rattles of the clip body during the retraction operation. Note that in this invention, "front" refers to the pen tip side, and "rear" refers to the opposite side of the retractable writing instrument. [Means for solving the problem]

[0011] The first invention of the present application is a retractable writing instrument that accommodates a writing body in a barrel so that the writing body can move back and forth, and that is configured so that the pen tip of the writing body can be retracted from a front end hole of the barrel, A slide hole extending in the front-rear direction is provided in the side wall of the barrel, A clip body projects radially outward from the slide hole, The clip body is configured to be movable in the front-rear direction along the slide hole, a retraction mechanism that slides the clip body forward from a retracted state to bring the pen tip into a protruding state from the front end hole of the barrel, and slides the clip body forward from the protruding state to bring the pen tip into a retracted state; The retractable mechanism is a cam portion formed on the inner surface of the barrel; a rotating member that engages with the cam portion and abuts against the rear end of the writing element; a clip body having cam teeth that engage with the rotating member; a first resilient body that is housed in the barrel and biases the writing element rearward; The clip body and the rotating member are locked together with some play in the front-rear direction, a second elastic body is interposed between the clip body and the rotating member; the second elastic body biases the rotation member forward relative to the clip body; the rotating member includes a front locking wall portion that locks a front end of the second elastic body, the clip body includes a rear locking wall portion that locks the rear end of the second resilient body, The front locking wall portion or the rear locking wall portion is locked to the second elastic body so as to be able to slide thereon.

[0012] In the retractable writing instrument of the first invention of the present application, the clip body is always urged backward by the second resilient body within the range of back-and-forth play between the clip body and the rotating member, so noise caused by rattle of the clip body is unlikely to occur. Furthermore, because the rotating member is urged forward by the second resilient body, the impact when the rotating member collides with another member is mitigated, thereby reducing the noise generated by the collision between the rotating member and another member.

[0013] Furthermore, since the front locking wall portion or the rear locking wall portion is engaged with the second spring body so as to be able to slide in contact with the second spring body, the rotation of the rotating member during the extension / retraction operation is not stopped by the second spring body, so that the pen tip extension / retraction operation can be performed reliably.

[0014] The second invention of the present application is the first invention, the second elastic body is a compression coil spring, When viewed from the rear of the retractable writing instrument, the spiral winding direction of the second spring body as it moves forward along the wire of the second spring body is the same as the rotation direction of the rotating member that rotates within the barrel during the retractable operation.

[0015] Due to the above-described configuration, the retractable writing instrument of the second invention of the present application is less likely to have the beginning (end) of the winding of the second spring body caught on the rotating member or clip body during the retraction / extension operation, and the rotation of the rotating member during the retraction / extension operation is not stopped by the second spring body, allowing for more reliable pen tip retraction / extension operation.

[0016] The third invention of the present application is the second invention, The rear end of the front locking wall portion is a plane perpendicular to the axial direction, and the front locking wall portion comes into contact with the front end of the second spring body, or the front end of the rear locking wall portion is a plane perpendicular to the axial direction, and the rear locking wall portion comes into contact with the rear end of the second spring body.

[0017] The retractable writing instrument of the third invention of the present application has the above-mentioned configuration, which makes it even less likely for the second spring body to get caught on the rotating member or clip body during the retraction operation, and the rotation of the rotating member is not stopped by the second spring body, allowing for more reliable pen tip retraction and extension.

[0018] A fourth aspect of the present invention is any one of the first to third aspects of the present invention, In a state where the first elastic body and the second elastic body are housed in the barrel, The load of the first elastic body is set to be always larger than the load of the second elastic body.

[0019] The retractable writing instrument of the fourth invention of the present application has the above-mentioned configuration in which the rotating member and the cam teeth of the clip body are in contact except when the pen tip is changed from a protruding state to a retracted state, thereby reducing the noise generated while maintaining the same pen tip protruding and retracting operation feel as conventional retractable writing instruments.

[0020] The fifth invention of the present application is the first to fourth inventions, In a state where the first elastic body and the second elastic body are housed in the barrel, The pen is characterized in that the load of the second elastic body is set in the range of 25% to 50% of the load of the first elastic body when the pen tip is protruded.

[0021] Due to the above-mentioned configuration, the retractable writing instrument of the fifth invention of the present application makes it difficult to feel the resistance of the second spring when changing the pen tip from a protruding state to a retracted state, and does not impair the conventional feel of the pen tip protruding and retracting operation. [Effects of the Invention]

[0022] The present invention provides a retractable writing instrument equipped with a retraction mechanism that causes the pen tip to retract by sliding the clip body forward, which is less likely to malfunction and is less likely to produce noise due to collisions between the rotating member and other members during the retraction operation or rattle of the clip body. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is a side view showing the pen tip immersed state of the present invention. [Figure 2] 2 is a side view showing the pen tip protruding state of FIG. 1. FIG. [Figure 3] FIG. 2 is a longitudinal sectional view of FIG. [Figure 4] FIG. 3 is a longitudinal sectional view of FIG. 2. [Figure 5] FIG. 2 is an enlarged longitudinal sectional view of the front shaft of FIG. 1. [Figure 6] FIG. 2 is an enlarged vertical cross-sectional view of the intermediate shaft of FIG. 1. [Figure 7] FIG. 2 is an enlarged vertical cross-sectional view of the rear body of FIG. 1. [Figure 8] FIG. 2 is an enlarged front view of the main part with some parts of FIG. 1 omitted. [Figure 9] FIG. 2 is a side view of the clip body of FIG. [Figure 10] FIG. 10 is a longitudinal cross-sectional view of FIG. 9. [Figure 11] FIG. 4 is a cross-sectional view taken along the arrows AA in FIG. 3. [Figure 12] FIG. 2 is a side view of the rotating member of FIG. [Figure 13] FIG. 13 is a longitudinal cross-sectional view of FIG. [Figure 14] 1 is an enlarged perspective view of a main part showing the rotation direction of the rotary member and the winding direction of the second resilient body (the dimensional relationship between the rotary member and the second resilient body is different). [Figure 15] FIG. 10 is an enlarged longitudinal cross-sectional view of a main part showing a sliding contact state of a second elastic body. [Figure 16] FIG. 2 is an enlarged longitudinal sectional view of a main part of FIG. [Figure 17] FIG. 3 is an enlarged longitudinal sectional view of a main part of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] 1 to 17 show an embodiment of the present invention. The retractable writing instrument 1 of this embodiment comprises a barrel 2, a writing element 13 housed in the barrel 2, and a retraction mechanism that allows the pen tip 131 of the writing element 13 to freely protrude and retract from the front end hole 31 of the barrel 2. In this embodiment, when the pen tip is retracted, the total axial length of the retractable writing instrument 1 is 150 mm.

[0026] ·Cursive 3 and 4, the writing element 13 comprises a pen tip 131, an ink reservoir 132 into whose front end opening the pen tip 131 is press-fitted, ink 133 filled in the ink reservoir 132, and a follower 134 (e.g., a high-viscosity fluid) filled at the rear end of the ink 133 and moving forward as the ink 133 is consumed. In this embodiment, the writing element 13 weighs 4.9 grams.

[0027] The pen tip 131 may be, for example, either a metal ballpoint pen tip that rotatably holds a ball at its front end, or a synthetic resin pen tip holder that holds the rear outer surface of the ballpoint pen tip. A tail plug 135 with a vent hole that allows ventilation between the ink reservoir 132 and the outside is attached to the rear end opening of the ink reservoir 132. A spring that presses the ball at the front end forward is housed inside the pen tip 131. The spring is a compression coil spring with a rod portion at the front end, and the front end of the rod portion contacts 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-facing front edge of the ballpoint pen tip, preventing ink 133 from leaking from the front end of the pen tip 131 and evaporation of the ink 133.

[0028] ·Shaft cylinder The barrel 2 comprises a tapered cylindrical front axle 3, a cylindrical intermediate axle 4 connected to the rear end of the front axle 3, and a cylindrical rear axle 5 connected to the rear end of the intermediate axle 4.

[0029] Figure 5 shows the front shaft 3. The front shaft 3 comprises a tapered cylindrical main body 3a made of a synthetic resin (for example, polycarbonate resin) molded body, and a grip portion 3b made of an elastic material and attached to the outer surface of the main body 3a. The grip portion 3b is formed by two-shot molding or by attachment to the outer surface of the main body 3a. The rear end of the front shaft 3 is reduced in diameter, and a male thread portion 32 is formed on its outer surface. A front end hole 31 is formed in the front end of the front shaft 3 in the front-to-rear direction. A decorative ring 33 is attached to the rear of the front shaft 3.

[0030] FIG. 6 shows the intermediate shaft 4. The intermediate shaft 4 is made of a cylindrical molded body made of synthetic resin (for example, polycarbonate resin). A female thread portion 46 is formed on the inner surface of the front end of the intermediate shaft 4. The male thread portion 32 of the front shaft 3 can be threadedly engaged with the female thread portion 46. A reduced diameter portion 43 is formed integrally with the rear end of the intermediate shaft 4. A first elongated hole 44 is formed in the side wall of the rear end of the intermediate shaft 4, extending in the front-to-rear direction and having a closed front end and an open rear end. Furthermore, an outward protrusion 45 is formed integrally with the outer surface of the reduced diameter portion 43. A stepped portion 42 is formed integrally with the inner surface of the intermediate shaft 4 forward of the reduced diameter portion 43. A cam portion 41 consisting of cam teeth 41 a and cam grooves 41 b is formed integrally with the inner surface of the intermediate shaft 4 forward of the stepped portion 42. The front end of the first elongated hole 44 is located slightly forward of the step 42 (i.e., the rear end of the cam portion 41) and rearward of the cam teeth 41a of the cam portion 41. A guide hole 48 extending in the front-rear direction is formed in the outer surface of the intermediate shaft 4 forward of the first elongated hole 44. A ball portion 81 of the clip body 7 is constantly engaged with the guide hole 48, and as the clip body 7 moves in the front-rear direction, the ball portion 81 can move in the front-rear direction along the guide hole 48.

[0031] FIG. 7 shows rear barrel 5. Rear barrel 5 is made of a cylindrical molded body made of synthetic resin (for example, polycarbonate resin). A second elongated hole 51 is formed in the side wall of the front end of rear barrel 5, with an open front end and a closed rear end, and extending in the front-to-rear direction. If ink 133 is a thermochromic ink (described below), a friction portion 14 may be attached to the rear end of rear barrel 5. An inward protrusion 52 is formed integrally with the inner surface of rear barrel 5. The width of second elongated hole 51 is set equal to the width of first elongated hole 44, thereby enabling smooth movement of clip body 7 in the front-to-rear direction along slide hole 21.

[0032] Clip body 9 to 11 show the clip body 7. The clip body 7 is composed of a clip main body 8 extending in the front-to-rear direction, a clip base 9 connected to the rear of the clip main body 8, and a cylindrical body 10 attached to the front of the clip base 9. In this embodiment, the weight of the clip body 7 is 5.9 grams. The clip body 7 may also be formed as a single, integrated part.

[0033] The clip body 8 is made of synthetic resin or metal. A plate-shaped ball portion 81 is integrally formed on the inner surface of the clip body 8 to protrude therefrom. The clip body 8 is fixed to the front portion of the protruding portion 91 of the clip base 9.

[0034] The clip base 9 is made up of a protruding portion 91 that is exposed from the barrel 2 and is pressed when the pen tip 131 extends or retracts, a cylindrical base 92 that is integrally connected to the protruding portion 91 and has an inner hole that passes through it in the axial direction, and a cylindrical connecting portion 93 that is integrally connected to the base 92 and extends forward from the base 92. A through hole 94 that passes through the base 92 and connecting portion 93 in the axial direction is provided radially inward of the base 92 and connecting portion 93. The clip base 9 is obtained by molding a synthetic resin (for example, polyacetal resin, polycarbonate resin).

[0035] The protruding portion 91 consists of a pressing portion 91a and a connecting portion 91b. The pressing portion 91a is exposed outward from the slide hole 21 of the barrel 2. The clip body 8 is fixed to the front of the pressing portion 91a. The pressing portion 91a and the base portion 92 are integrally connected by the connecting portion 91b. As shown in FIG. 11, the width dimension of the connecting portion 91b is smaller than the width dimension of the pressing portion 91a. When the retractable writing instrument 1 is assembled, the connecting portion 91b is arranged within the slide hole 21 so that it can move back and forth in the forward and backward directions.

[0036] A rib 92a extending in the front-rear direction is formed on the outer surface of the base 92. The rib 92a engages with a groove 49 extending in the front-rear direction formed on the inner surface of the rear end of the intermediate shaft 4, and the rib 92a moves in the front-rear direction along the groove 49. This makes it possible to suppress wobbling of the clip body 7 in the circumferential direction.

[0037] The connecting portion 93 comprises a large-diameter portion 93a and a small-diameter portion 93b that is connected forward from the large-diameter portion 93a and has a smaller outer diameter than the large-diameter portion 93a. An outward protrusion 93c is integrally formed on the outer surface of the small-diameter portion 93b. The outward protrusion 93c may be, for example, a ring-shaped protrusion or a plurality of dispersed protrusions arranged circumferentially.

[0038] An inward protrusion 95 is provided on the inner surface of the through hole 94 (radially inward of the base 92). The inward protrusion 95 is an annular protrusion. The inner diameter of the inward protrusion 95 gradually decreases toward the rear, thereby improving the ease of insertion and assembly when the rotating member 6 and the clip body 7 are fitted together and engaged. A rear locking wall portion 96 having a flat surface perpendicular to the axial direction at its front end is connected to the front of the inward protrusion 95. The rear locking wall portion 96 is annular. The inner diameter of the rear locking wall portion 96 is the same as the maximum inner diameter of the inward protrusion 95. The inner diameter of the rear locking wall portion 96 is smaller than the inner diameter of the second elastic pressure body 12. A rotating member locking wall portion 97 having a flat surface perpendicular to the axial direction at its rear end is connected to the rear of the inward protrusion 95. The rotating member locking wall portion 97 is annular. The inner diameter of the rotating member locking wall portion 97 is the same as the minimum inner diameter of the inward protrusion 95. In this embodiment, the inner diameter of the through hole 94 in front of the front locking wall portion 64 is 3.05 mm. The inner diameter of the rotation member locking wall portion 97 is 1.55 mm.

[0039] The cylindrical body 10 is cylindrical and is attached to the outer surface of the connecting portion 93 of the clip base 9. Cam teeth 10a are formed at the front end of the cylindrical body 10. An inner hole penetrates the cylindrical body 10 in the front-rear direction, and an inward protrusion 10b is integrally formed on the inner surface of the cylindrical body 10. The inward protrusion 10b and the outward protrusion 93c of the clip base 9 are engaged to move the clip base 9 and the cylindrical body 10 together in the front-rear direction. A plurality of guide protrusions 10c are integrally formed on the outer surface of the cylindrical body 10, and the guide protrusions 10c engage with the cam grooves 41b of the cam portion 41 so as to be movable in the front-rear direction, thereby preventing the cylindrical body 10 from rotating within the barrel 2. The cylindrical body 10 is obtained by molding a synthetic resin (e.g., polyacetal resin). Preferably, the cylindrical body 10 is formed from a polyacetal resin of a grade with high slidability and containing a lubricant. The base 92 and the cylindrical body 10 may be integrally formed.

[0040] Rotating parts 12 and 13 show the rotating member 6. The rotating member 6 comprises a first tubular portion 61, a plurality of (e.g., four) ridges 62 extending in the front-rear direction on the outer surface of the first tubular portion 61, a second tubular portion 63 connected to the rear of the first tubular portion 61, and a shaft portion 65 connected to the rear of the second tubular portion 63. The first tubular portion 61 is cylindrical. The second tubular portion 63 is connected to the rear of the first tubular portion 61 integrally with the first tubular portion 61 via a step portion 61a. The ridges 62 are integrally formed on the outer surface of the first tubular portion 61 and the step portion 61a. The ridges 62 engage with the cam teeth 41a and the cam grooves 41b of the cam portion 41. The second tubular portion 63 is cylindrical and has a bottom. A circular front engagement wall portion 64 having a flat surface perpendicular to the axial direction at its rear end is integrally formed on the rear of the second tubular portion 63. The outer diameter of the front locking wall 64 is smaller than the outer diameter of the second cylindrical portion 63. A chamfered portion 63a is provided between the second cylindrical portion 63 and the front locking wall 64. The outer surface of the chamfered portion 63a gradually decreases in diameter toward the rear, improving the ease of assembly when inserting the rotating member 6 into the cylindrical body 10. A cylindrical shaft portion 65 extending in the axial direction is integrally provided behind the front locking wall 64. The shaft portion 65 is provided at the axis of the rotating member 6. In this embodiment, the outer diameter of the shaft portion 65 is 1.90 mm. The rotating member 6 is obtained by molding a synthetic resin (e.g., polyacetal resin). Preferably, the rotating member 6 is formed from a polyacetal resin of a grade with high slidability that is blended with a lubricant.

[0041] A small diameter shaft portion 66 having an outer diameter smaller than that of the shaft portion 65 is provided behind the shaft portion 65. The outer diameter between the shaft portion 65 and the small diameter shaft portion 66 gradually decreases toward the rear, making it difficult for breakage to occur between the shaft portion 65 and the small diameter shaft portion 66. The outer diameter of the small diameter shaft portion 66 is smaller than the minimum inner diameter of the inward protrusion 95 of the clip base 9 (the inner diameter of the rotating member locking wall portion 97). In this embodiment, the outer diameter of the small diameter shaft portion 66 is 1.40 mm.

[0042] An outward protrusion 67 is provided at the rear of the small-diameter shaft portion 66. The side surface of the outward protrusion 67 does not contact the clip base 9, so the outward protrusion 67 does not hinder the rotation of the rotating member 6. The outer diameter of the outward protrusion 67 is larger than the minimum inner diameter of the inward protrusion 95 (the inner diameter of the rotating member locking wall portion 97). In this embodiment, the outer diameter of the outward protrusion 67 is 1.77 mm. A tip portion 67a is provided adjacent to the rear of the outward protrusion 67. The outer diameter of the tip portion 67a gradually decreases toward the rear, improving the ease of insertion and assembly when the rotating member 6 and the clip body 7 are engaged by passing over each other. Because the outward protrusion 67 is not exposed outside the barrel 2, the shape and axial length of the tip portion 67a can be freely set. The axial length of the tip portion 67a is longer than the axial length of the inward protrusion 95. More preferably, the axial length of the tip portion 67a is longer than the combined axial length of the inward protrusion 95, the rear locking wall portion 96, and the rotating-member locking wall portion 97. This configuration allows the rotating member 6 and the clip body 7 to more smoothly ride over and engage with each other. By setting the tip portion 67a to be longer, the tip portion 67a protrudes rearward from the base portion 92. However, since the tip portion 67a is housed within the barrel tube 2, there is no risk of the outward protrusion 67 coming into contact with other objects and being damaged. A step portion 67b is provided between the small-diameter shaft portion 66 and the outward protrusion 67. The outer diameter of the step portion 67b gradually increases toward the rear, resulting in an annular line contact between the outward protrusion 67 and the rotating-member locking wall portion 97. This reduces the contact area between the outward protrusion 67 and the rotating-member locking wall portion 97, thereby reducing the noise generated when the outward protrusion 67 and the rotating-member locking wall portion 97 collide in the axial direction.

[0043] Assembly of retractable writing implements The assembly of the retractable writing instrument 1 will now be described. The base 92 of the clip body 7 is inserted into the first elongated hole 44 of the intermediate shaft 4 through the rear-end opening of the first elongated hole 44. Next, the cylindrical body 10 is inserted from the front of the intermediate shaft 4, causing the inward protrusion 10b of the cylindrical body 10 to slide over and engage with the connecting portion 93 of the clip base 9. Next, the second spring body 12 is attached to the shaft portion 65 of the rotating member 6, and the rotating member 6 is inserted from the front of the intermediate shaft 4, causing the outward protrusion 67 of the rotating member 6 to slide over and engage with the inward protrusion 95 of the clip body 7. This prevents the clip body 7 from slipping out of the rotating member 6. At this time, the rotating member 6 is rotatably attached with some play in the front-rear direction. The play in the front-rear direction (amount of movement) is set small enough to allow the protrusion 61 of the rotating member 6 to engage and disengage with the cam teeth 41a of the cam portion 41. The second resilient body 12 constantly urges the rotational member 6 forward, and constantly urges the clip body 7 backward within the range of the back-and-forth play. In this embodiment, the back-and-forth play of the rotational member 6 is 0.50 mm.

[0044] Thereafter, the inner surface of the rear shaft 5 is fitted onto the outer surface of the reduced diameter portion 43 of the intermediate shaft 4 so as to radially communicate the first elongated hole 44 of the intermediate shaft 4 and the second elongated hole 51 of the rear shaft 5 (so as to overlap in the radial direction), and the base 92 of the clip body 7 is inserted into the second elongated hole 51 from the front-end open portion of the second elongated hole 51. As a result, the intermediate shaft 4 and the rear shaft 5 are coupled together, and a slide hole 21 extending in the front-rear direction is formed by the first elongated hole 44 and the second elongated hole 51 as shown in FIG. 8 , and the clip body 7 (clip main body 8 and protruding portion 91) protrudes radially outward from the slide hole 21, so that the clip body 7 is slidable in the front-rear direction along the slide hole 21 (slidable in the front-rear direction). At this time, the outward protrusion 45 on the outer surface of the reduced diameter portion 43 of the intermediate shaft 4 and the inward protrusion 53 on the inner surface of the rear shaft 5 ride over and engage with each other.

[0045] Writing body 13 is inserted from the front of intermediate shaft 4, and first spring body 11 is inserted from the rear of front shaft 3, and then front shaft 3 and intermediate shaft 4 are detachably connected by screwing together. Writing body 13 can be replaced by releasing the screw connection between front shaft 3 and intermediate shaft 4.

[0046] ·Appearance mechanism The retraction mechanism is a side-slide type mechanism using a rotary cam mechanism. The retraction mechanism includes a cam portion 41 formed on the inner surface of the intermediate shaft 4, a rotating member 6 that engages with the cam portion 41 and abuts against the rear end of the writing element 13, a clip body 7 that engages with the rotating member 6 and protrudes radially outward from the slide hole 21, a first spring 11 that is housed in the barrel 2 and urges the writing element 9 rearward, and a second spring 12 that is provided between the clip body 7 and the rotating member 6 and urges the rotating member 6 and the clip body 7 in a direction separating them from each other. The retraction mechanism of this embodiment is a double-knock type in which the clip body 7 slides forward for both the pen tip extension operation and the pen tip retraction operation.

[0047] The cam portion 41 has a plurality of sawtooth-shaped cam teeth 41a that protrude forward, and a plurality of cam grooves 41b that extend in the front-rear direction and are formed between the cam teeth 41a. The rotating member 6 has a plurality of (for example, four) ridges 62 that extend in the longitudinal direction on its outer surface, and the ridges 62 engage with the cam teeth 41a and cam grooves 41b of the cam portion 41. Cam teeth 10a that engage with the rear ends of the ridges 62 of the rotating member 6 are formed integrally with the front end of a cylindrical body 10 attached to the connecting portion 93 of the clip body 7.

[0048] The first resilient body 11 and the second resilient body 12 are compression coil springs. In particular, as shown in FIG. 14, when viewed from the rear of the retractable writing instrument 1, the spiral winding direction (b) of the second resilient body 12 as it moves forward along the wire rod is the same as the rotation direction (a) of the rotating member 6 that rotates within the barrel 2 during the retraction operation. In this embodiment, the winding direction of the second resilient body 12 is right-handed. In this embodiment, when viewed from the rear of the retractable writing instrument 1, the rotation direction of the rotating member 6 during the pen tip retraction operation is right-handed (clockwise).

[0049] In the pen tip protruding state, the load of the first resilient body 11 is preferably in the range of 150 grams to 250 grams. It is more preferable that the load of the first resilient body 11 is in the range of 200 grams to 250 grams. If the load of the first resilient body 11 is too small, the pen tip protruding and retracting operation cannot be performed, and if it is too large, the collision noise between the rotating member 6 and other members (specifically, the rotating member 6 and the cam teeth 41a of the cam portion 41, and the cam teeth 10a of the cylindrical body 10 of the clip body 7) generated during the pen tip protruding and retracting operation becomes louder.

[0050] The load of the second resilient body 12 is set to be greater than the weight of the clip body 7. With this configuration, the clip body 7 does not rattle when the pen tip is protruding.

[0051] The second resilient body 12 is provided between the rotating member 6 and the clip body 7 (specifically, radially outward from the shaft portion 65 of the rotating member 6 and radially inward from the cylindrical body 10). The shaft portion 65 passes through the axis of the second resilient body 12. The outer diameter of the second resilient body 12 is smaller than the inner diameter of the through-hole 94 forward of the front locking wall portion 64. The inner diameter of the second resilient body 12 is larger than the outer diameter of the shaft portion 65. The second resilient body 12 urges the rotating member 6 and the clip body 7 in directions separating them from each other, but the rotating member 6 and the clip body 7 are locked together so as to prevent them from coming off each other.

[0052] The second resilient body 12 has a symmetrical shape from front to back and has wound end portions 12a at both ends. The number of wound end portions 12a is two or more. More preferably, the number of wound end portions 12a is five or more. Even more preferably, the number of wound end portions 12a is eight or more. With this configuration, the wound end portion 12a serves as a guide when assembling the retractable writing instrument 1, allowing the second resilient body 12 to be smoothly inserted into the shaft portion 65, improving the assembly of the retractable writing instrument 1. Furthermore, the wound end portion 12a reduces the inclination angle of the winding start portion (winding end portion) 12b with respect to a plane perpendicular to the axial direction, making it less likely for the winding start portion (winding end portion) 12b to get caught on the front locking wall portion 64 or the rear locking wall portion 96, ensuring reliable pen tip extension and retraction.

[0053] Since the axial length of the tip portion 67a is longer than the axial length of the end turn portion 12a, the second resilient body 12 can be smoothly inserted and attached to the shaft portion 65. Furthermore, since the combined axial length of the outward protrusion 67 and the tip portion 67a is longer than the gap between the wires that make up the second resilient body 12, the second resilient body 12 and the outward protrusion 67 are less likely to get caught.

[0054] The front locking wall portion 64 or the rear locking wall portion 96 is engaged with the second resilient body 12 to allow sliding contact therebetween. The front locking wall portion 64 and the rear locking wall portion 96 may also be engaged with the second resilient body 12 to allow sliding contact therebetween. When the front locking wall portion 64 and the second resilient body 12 are engaged with each other to allow sliding contact therebetween, the frontmost end of the second resilient body 12, which comes into line contact with the front locking wall portion 64, is a circumferential linear region A that is a part of the frontmost end of the wire in the end winding portion 12a. When the rear locking wall portion 96 and the second resilient body 12 are engaged with each other to allow sliding contact therebetween, the rearmost end of the second resilient body 12, which comes into line contact with the rear locking wall portion 96, is a circumferential linear region B that is a part of the rearmost end of the end winding portion 12a (see FIGS. 14 and 15). With the above configuration, the start (end) of winding 12b of the second spring body 12 does not get caught on the front retaining wall portion 64 or the rear retaining wall portion 96, making it less likely that the second spring body 12 will get caught on the rotating member 6 during the extension / retraction operation, and allowing the pen tip to be extended or retracted more reliably.

[0055] If the front locking wall portion 64 or the rear locking wall portion 96 does not have a plane perpendicular to the axial direction (for example, a tapered shape, a hemispherical shape, etc.), the beginning (end) of the winding 12b of the second elastic body 12 may get caught on the front locking wall portion 64 or the rear locking wall portion 96.

[0056] When the first resilient body 11 and the second resilient body 12 are housed in the barrel, the load of the first resilient body 11 is set to be always greater than the load of the second resilient body 12. With this configuration, the protrusion 62 of the rotating member 6 and the cam teeth 10a of the cylindrical body 10 are in contact except when the pen tip is changed from the extended state to the retracted state, so that it is possible to reduce the generated noise while maintaining the same pen tip extension and retraction operation feel as in conventional retractable writing instruments. When changing the pen tip from the extended state to the retracted state, the clip body 7, which is biased rearward by the amount of play, must be slid against the bias of the second resilient body 12. However, because the load of the second resilient body 12 is set in the range of 25% to 50% of the load of the first resilient body 11, the second resilient body 12 does not provide significant resistance when the pen tip is retracted. It is more preferable that the load of the second resilient body 12 is set in the range of 30% to 40% of the load of the first resilient body 11.

[0057] The operation of the retraction mechanism when changing from the pen tip retracted state to the pen tip extended state will be described. When the clip body 7 is slid forward from the pen tip retracted state shown in FIGS. 1, 3, and 16 against the rearward bias of the first spring 11, the cylindrical body 10 of the clip body 7 presses the rotating member 6 forward. As the protrusion 62 of the rotating member 6 moves forward along the cam groove 41b, the rotating member 6 presses the rear end of the writing element 13 forward, causing the pen tip 131 to protrude outward from the front-end hole 31. At this time, the cam teeth 10a of the cylindrical body 10 abut against the protrusion 62 of the rotating member 6, causing the rotating member 6 to rotate a certain angle relative to the cam portion 41. As a result, the protrusion 62 of the rotating member 6 engages with the cam teeth 41a of the cam portion 41, maintaining the pen tip extended state. When the cam teeth 10a of the cylindrical body 10 come into contact with the ridges 62 of the rotary member 6, and when the ridges 62 of the rotary member 6 engage with the cam teeth 41a of the cam portion 41, a collision sound is generated.

[0058] The operation of the retraction mechanism when changing from the pen tip extended state to the pen tip retracted state will now be described. When clip body 7 is slid forward from the pen tip extended state shown in FIGS. 2, 4, and 17, first, cam teeth 10a of cylindrical body 10 and protrusion 62 of rotating member 6 come into contact against the rearward bias of second resilient body 12. When clip body 7 is subsequently slid forward, cylindrical body 10 presses rotating member 6 forward against the rearward bias of first resilient body 11, and cam teeth 10a of cylindrical body 10 come into contact with protrusion 62 of rotating member 6, causing rotating member 6 to rotate a certain angle relative to cam portion 41. This releases the engagement between protrusion 62 and cam teeth 41a of cam portion 41, and the rearward bias of first resilient body 11 causes protrusion 62 to move rearward along cam groove 41b of cam portion 41. As the rotating member 6 moves backward, the writing element 13 also moves backward, and the pen tip is retracted. When the cam teeth 10a of the cylindrical body 10 come into contact with the protrusions 62 of the rotating member 6, and when the protrusions 62 move to the position of the cam grooves 41b of the cam portion 41, a collision sound is generated.

[0059] When the pen tip 131 is extended or retracted, the rotating member 6 receives a forward biasing force from the second resilient body 12. This forward biasing force reduces the momentum of the axial collision between the rotating member 6 and another member due to the backward biasing force of the first resilient body 11. At the same time, the rotating member 6 receives a frictional force in the rotational direction about the axis from the second resilient body 12. This frictional force acts in the opposite direction to the rotation of the rotating member 6 during the extension / retraction operation, reducing the momentum of the collision between the rotating member 6 and another member in the rotational direction. This frictional force is not large enough to interfere with the pen tip extension / retraction operation. In this way, the second resilient body 12 reduces the momentum of the collision between the rotating member 6 and another member, thereby reducing the sound generated when the rotating member 6 and another member collide.

[0060] ·Friction part The elastic material constituting the friction portion 14 is preferably an elastic synthetic resin (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, ethylene propylene diene rubber (EPDM), etc. The elastic synthetic resin constituting the friction portion 14 is preferably made of a low-wear elastic material that hardly produces wear debris (eraser dust) during friction, rather than a highly wear-resistant elastic material (such as an eraser).

[0061] Friction portion 14 may be provided at the rear of barrel 2, and examples of such configurations include a configuration in which friction portion 14 made of an elastic material is fixed to the rear end of barrel 2 or to the rear of rear axle 5 by press-fitting, engaging, screwing, mating, bonding, two-color molding, or the like, or a configuration in which the entire barrel 2 or the entire rear axle 5 is integrally formed from an elastic material. Furthermore, friction portion 14 may be attached to barrel 2 via retainer 15 to which friction portion 14 is fixed. In this embodiment, rear axle 5 and retainer 15 are detachably attached by screwing, so that friction portion 14 can be easily replaced by removing retainer 15.

[0062] Thermochromic ink In this embodiment, the ink 133 may be a reversible thermochromic ink. The reversible thermochromic ink may be of various types, such as a thermal decolorization type that is decolorized by heating from a colored state, a color memory retention type that alternately stores and retains a colored or decolorized state within a specific temperature range, or a thermal color development type that develops color from a decolorized state by heating and returns to the decolorized state by cooling from the colored state, or may be used alone or in combination. Handwriting with the reversible thermochromic ink can easily change color due to frictional heat from the friction portion 14.

[0063] The retractable writing instrument 1 of this embodiment is a retractable writing instrument that accommodates a writing body 13 within a barrel 2 so as to be movable in the front-rear direction, and is configured so that a pen tip 131 of the writing body 13 can be projected and retracted from a front-end hole 31 of the barrel. The retractable writing instrument is provided with a slide hole 21 extending in the front-rear direction in the side wall of the barrel 2, a clip body 7 protruding radially outward from the slide hole 21, and is configured so as to be movable in the front-rear direction along the slide hole 21. The retractable writing instrument is provided with a retractable mechanism that causes the pen tip 131 to protrude from the front-end hole 31 of the barrel 2 by sliding the clip body 7 forward from a pen tip retracted state, and causes the pen tip 131 to retract by sliding the clip body 7 forward from a pen tip protruding state. The retractable writing instrument includes a cam portion 41 formed on the inner surface of the barrel 2, a rotary member 6 that engages with the cam portion 41 and abuts against the rear end of the writing body 13, and cam teeth 10a that engage with the rotary member 6. and a first spring body 11 housed in the barrel 2 and urging the writing element 13 rearward, the clip body 7 and the rotating element 6 are locked together with some play in the front-rear direction, a second spring body 12 is interposed between the clip body 7 and the rotating element 6, the second spring body 12 urges the rotating element 6 forward relative to the clip body 7, and the rotating element 6 locks the front end of the second spring body 12. The clip body 7 has a front locking wall portion 64 that locks the rear end of the second resilient body 12, and the front locking wall portion 64 or the rear locking wall portion 96 is slidably locked to the second resilient body 12, so that the clip body 7 is always urged rearward by the second resilient body 12 within the range of play in the front-to-rear direction between the clip body 7 and the rotating member 6, making it difficult for noise to be generated due to rattle of the clip body 7. Furthermore, because the rotating member 6 is urged forward by the second resilient body 12, the impact when the rotating member 6 collides with another member is alleviated, thereby reducing noise generated by the collision between the rotating member 6 and another member. Furthermore, since the front locking wall portion 64 or the rear locking wall portion 96 is engaged with the second spring body 12 so as to be able to slide in contact with the second spring body 12, the rotation of the rotating member 6 during the extension / retraction operation is not stopped by the second spring body 12, so that the pen tip extension / retraction operation can be performed reliably.

[0064] In the retractable writing instrument 1 of this embodiment, the second resilient body 12 is a compression coil spring, and when viewed from the rear of the retractable writing instrument 1, the spiral winding direction of the second resilient body 12 as it moves forward along the wire of the second resilient body 12 is the same as the rotation direction of the rotating member 6 that rotates within the barrel 2 during the retraction / extension operation.As a result, the start (end) of the winding 12b of the second resilient body 12 is less likely to get caught on the rotating member 6 or the clip body 7 during the retraction / extension operation, and the rotation of the rotating member 6 during the retraction / extension operation is not stopped by the second resilient body 12, allowing for more reliable pen tip retraction / extension operation.

[0065] In the retractable writing instrument 1 of this embodiment, the rear end of the front locking wall portion 64 is a plane perpendicular to the axial direction, and the front locking wall portion 64 comes into contact with the front end A of the second springing body 12, or the front end of the rear locking wall portion 96 is a plane perpendicular to the axial direction, and the rear locking wall portion 96 comes into contact with the rear end B of the second springing body 12, making it even less likely that the second springing body 12 will get caught on the rotating member 6 or clip body 7 during the retraction / extension operation, and since the rotation of the rotating member 6 is not stopped by the second springing body 12, the pen tip retraction operation can be performed more reliably.

[0066] In the retractable writing instrument 1 of this embodiment, when the first resilient body 11 and the second resilient body 12 are housed in the barrel 2, the load of the first resilient body 11 is set to be always greater than the load of the second resilient body 12. As a result, the protrusion 62 of the rotating member 6 and the cam tooth 10a of the clip body 7 are in contact except when the pen tip 131 is changed from the protruding state to the retracted state, so that the noise generated can be reduced while maintaining the same pen tip protrusion and retraction operation feel as with conventional retractable writing instruments.

[0067] In the retractable writing instrument 1 of this embodiment, when the first resilient body 11 and the second resilient body 12 are housed in the barrel 2 and the pen tip 131 is protruded, the load of the second resilient body 12 is set to a range of 25% to 50% of the load of the first resilient body 11, so that when the pen tip 131 is changed from a protruding state to a retracted state, the resistance of the second resilient body 12 is hardly felt, and the conventional pen tip protruding and retracting operation feel is not impaired. [Explanation of symbols]

[0068] 1 Removable writing instrument 2 shaft cylinder 21 Slide hole 3 Front axle 31 Front end hole 32 Male thread 33 Decorative Ring 3a Main body 3b Grip part 4 Intermediate shaft 41 Cam section 41a cam teeth 41b Cam groove 42 Stepped section 43 Reduced diameter part 44 First slot 45 External process 46 Female thread 47 Locking protrusion 48 Guide hole 49 Groove 5 rear axle 51 Second slot 52 Introvert process 6 Rotating members 61 First cylindrical part 61a Stepped section 62 protrusion 63 Second cylindrical part 63a Chamfered part 64 Front retaining wall 65 Shaft 66 Small diameter shaft 67 External process 67a Tip 67b Stepped section 7 Clip body 8 Clip body 81 Tamabe 9 Clip Base 91 Protrusion 91a Pressing part 91b Connection part 92 Base 92a Rib 93 Connection 93a Large diameter section 93b Small diameter section 93c External process 94 Through holes 95 Introvert process 96 Rear retaining wall 97 Rotating member locking wall 10 Cylinder 10a cam teeth 10b Introvert process 10c Guide protrusion 11 First spring 12 Second spring 12a End winding 12b Starting point of winding (ending point of winding) 13 Cursive 131 Pen Tip 132 Ink reservoir 133 Ink 134 Follower 135 tail plug 14 Friction part 15 Holder

Claims

1. A retractable writing instrument in which a writing body is accommodated in a barrel so as to be movable in the front-rear direction, and a pen tip of the writing body is configured to be retractable from a front end hole of the barrel, A slide hole extending in the front-rear direction is provided in the side wall of the barrel, A clip body projects radially outward from the slide hole, The clip body is configured to be movable in the front-rear direction along the slide hole, a retraction mechanism that slides the clip body forward from a retracted state to bring the pen tip into a protruding state from the front end hole of the barrel, and slides the clip body forward from the protruding state to bring the pen tip into a retracted state; The retractable mechanism is a cam portion formed on the inner surface of the barrel; a rotating member that engages with the cam portion and abuts against the rear end of the writing element; a clip body having cam teeth that engage with the rotating member; a first spring body that is housed in the barrel and biases the writing element rearward; The clip body and the rotating member are locked together with some play in the front-rear direction, a second elastic body is interposed between the clip body and the rotating member; the second elastic body biases the rotation member forward relative to the clip body; the rotating member includes a front locking wall portion that locks a front end of the second elastic body, the clip body includes a rear locking wall portion that locks the rear end of the second resilient body, A retractable writing implement, characterized in that the front engaging wall portion or the rear engaging wall portion is engaged with the second resilient body so as to be able to slide against the second resilient body.

2. the second elastic body is a compression coil spring, A retractable writing instrument as described in claim 1, characterized in that, when viewed from the rear of the retractable writing instrument, the spiral winding direction when moving forward along the wire of the second spring body is the same as the rotation direction of the rotating member that rotates within the barrel during the retractable operation.

3. A retractable writing instrument as described in claim 2, characterized in that the rear end of the front engaging wall portion is a plane perpendicular to the axial direction, and the front engaging wall portion contacts the front end of the second spring body, or the front end of the rear engaging wall portion is a plane perpendicular to the axial direction, and the rear engaging wall portion contacts the rear end of the second spring body.

4. In a state in which the first elastic body and the second elastic body are housed in the barrel, 4. The retractable writing implement according to claim 1, wherein the load of the first resilient body is set to be always larger than the load of the second resilient body.

5. In a state in which the first elastic body and the second elastic body are housed in the barrel, A retractable writing instrument as described in any one of claims 1 to 4, characterized in that when the pen tip is protruded, the load of the second elastic body is set to a range of 25% to 50% of the load of the first elastic body.

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