Telescopic writing instrument

Abstract

The present invention relates to a telescopic writing instrument. The object is to effectively suppress impact and vibration accompanying a writing operation. A telescopic writing instrument has a middle core (20) having a writing portion (21) at a front end, a force applying member (30) applying force to the middle core in a rear direction, a support member (41) supporting the middle core from the rear, a rotor (42) provided on the rear side of the support member and capable of advancing and retreating and rotating with respect to the shaft cylinder, and an annular elastic member (43) that repels the support member in the forward direction with respect to the rotor with a force greater than the force of the force applying member, and is configured to project the writing portion and maintain the projected state by advancing the rotor against the force of the force applying member and latching the rotor to the shaft cylinder. The support member integrally has a support portion (41a) that supports the rear end of the middle core from the rear and a shaft portion (41b) that projects in the rear direction from the support portion. The annular elastic member is annularly mounted to the shaft portion. The rotor is fitted to the shaft portion so as to be capable of advancing and retreating.

Description

Technical Field

[0001] This invention relates to a telescopic writing tool in which the writing part extends and retracts from the front end of the shaft cylinder by a press operation. Background Technology

[0002] In the past, such inventions included a type of writing instrument that could extend and retract from the front end of the cylinder, as described in Patent Document 1. This instrument included a writing body that extended and retracted from the front end of the cylinder, a return spring that applied force to the writing body to the rear, a second spring that supported the writing body from the rear and retracted, and a rotor that was concavely fitted with the cylindrical portion of the writing body on the rearward side and the second spring. The rotor was then stopped in the cylinder during forward movement, maintaining the protruding state of the writing body.

[0003] Patent document 1 describes that "by assembling the second spring, a cushioning effect can be obtained, and by preventing fatigue caused by long-term writing or mitigating the impact of falling, the pen tip can also be protected and the structure simplified."

[0004] Patent Document 1: Japanese Utility Model Application Publication No. 60-157284

[0005] However, according to the aforementioned existing technology, the buffering effect of the second spring may not be fully utilized due to factors such as the off-center writing and deflection of the writing. Summary of the Invention

[0006] In view of this problem, the present invention has the following structure.

[0007] The telescopic writing instrument is characterized by having a core with a writing section at its front end within a cylindrical shaft, a force-applying component that applies force to the core rearward, a support component that supports the core from the rear, a rotor disposed at the rear of the support component and capable of moving forward and backward relative to the cylindrical shaft, and an annular elastic component that springs the support component forward relative to the rotor with a force greater than the force of the force-applying component. The telescopic writing instrument is configured such that the rotor advances against the force of the force-applying component and is locked in the cylindrical shaft, causing the writing section to protrude and maintain this protruding state. The support component integrally includes a support portion that supports the rear end of the core from the rear and a shaft portion protruding rearward from the support portion. The annular elastic component is annularly mounted on the shaft portion, and the rotor is capable of moving forward and backward into the shaft portion.

[0008] Invention Effects

[0009] As described above, this invention effectively suppresses the impact and vibration that accompany writing. Attached Figure Description

[0010] Figure 1 This is a complete cross-sectional view showing an example of the writing instrument involved in this invention. Figure 1 (a) shows the state in which the writing section is retracted. Figure 1 (b) shows the state in which the writing part is highlighted.

[0011] Figure 2 This is a half-sectional view representing the rotor unit of the writing instrument.

[0012] Figure 3 In this rotor unit, Figure 3 (a) shows the support component in its initial position. Figure 3 (b) shows the state in which the support component retracts and comes into contact with the rotor.

[0013] Figure 4 This is an exploded 3D view of the rotor unit.

[0014] Figure 5 The image shows the rotor unit assembled into the shaft cylinder. The shaft cylinder is shown in full sectional view, and the rotor unit is shown in side view.

[0015] Explanation of reference numerals in the attached figures

[0016] 10-Shaft cylinder, 13b-Overlapping fitting protrusion, 20-Central core, 21-Writing part, 30-Force-applying component, 40-Rotor unit, 41-Support component, 41a-Support part, 41b-Shaft part, 41b1-Front sliding part, 41b31-Rear sliding part (locking part), 41b32-Press-in part, 41b33-Gap insertion part, 42-Rotor, 42a-Large diameter part, 42b-Small diameter part, 42b1-Locked part (circular hole), 43-Annular elastic component, A-Writing tool. Detailed Implementation

[0017] The following features are disclosed in this embodiment.

[0018] The first feature is that the retractable writing instrument comprises, within a cylindrical shaft, a core with a writing section at its front end, a force-applying component that applies force to the core rearward, a support component that supports the core from the rear, a rotor disposed at the rear of the support component and capable of moving forward and backward relative to the cylindrical shaft, and an annular elastic component that springs the support component forward relative to the rotor with a force greater than the force applied by the force-applying component. The retractable writing instrument is configured such that the rotor advances against the force applied by the force-applying component and is locked in the cylindrical shaft, causing the writing section to protrude and maintain this protruding state. The support component integrally comprises a support portion that supports the rear end of the core from the rear and a shaft portion protruding rearward from the support portion. The annular elastic component is annularly mounted on the shaft portion, and the rotor is capable of moving forward and backward into the shaft portion (see reference). Figures 1-5 ).

[0019] As a second feature, the rotor is formed as a generally cylindrical portion having a large diameter portion and a small diameter portion with a reduced inner circumferential surface diameter at the rear end of the large diameter portion. The large diameter portion covers the periphery of the annular elastic member, and the small diameter portion supports the rear end of the annular elastic member (see reference). Figure 2 ).

[0020] As a third feature, the shaft portion extends through the annular elastic member and has an engaging portion located rearward of the annular elastic member, which engages with the engaging portion provided on the small-diameter portion by a predetermined amount (see reference). Figure 2 ).

[0021] As a fourth feature, the engaging portion is a through-hole circular hole, and on the outer periphery rearward of the engaging portion, there is a pressing portion that is pressed into the inner circumferential surface of the circular hole and passes through the circular hole, and a gap insertion portion that is adjacent to the pressing portion in the circumferential direction and passes through the circular hole without contacting the inner circumferential surface of the circular hole (see reference). Figure 2 and Figure 4 ).

[0022] As a fifth feature, the shaft portion is provided with a sliding portion that slides with the rotor in the front-rear direction (see reference). Figure 2 ).

[0023] As a sixth feature, the sliding portion has a front sliding portion located at a position forward of the annular elastic member and a rear sliding portion located at a position rear of the annular elastic member (see reference). Figure 2 ).

[0024] As a seventh feature, the support member is rotatably connected to the rotor (see reference). Figure 2 and Figure 4 ).

[0025] As an eighth feature, the rotor can be retracted and engaged with the shaft portion without separation, and the support member, the rotor, and the annular elastic member constitute an integral rotor unit (see reference). Figure 2 and Figure 5 ).

[0026] <Detailed Implementation>

[0027] Next, a detailed description of specific embodiments having the above features will be provided with reference to the accompanying drawings.

[0028] In this specification, "axial direction" refers to the direction in which the center line of the shaft extends, and "circumferential direction" refers to the direction around the center line of the shaft. Furthermore, "front" indicates the direction in which the writing portion protrudes from one side of the shaft along the axial direction, and "rear" indicates the side in the opposite direction.

[0029] Furthermore, in this specification, the radial direction of the shaft tube indicates the diameter direction of the shaft tube orthogonal to the center line of the shaft tube, the outer radial direction of the shaft tube indicates the direction away from the center of the shaft tube along the radial direction of the shaft tube, and the inner radial direction of the shaft tube indicates the direction towards the center of the shaft tube along the radial direction of the shaft tube.

[0030] Furthermore, in this specification, the radial direction of the core refers to the diameter direction of the core orthogonal to the center line of the core, the outer radial direction of the core refers to the direction away from the center of the core along the radial direction of the core, and the inner radial direction of the core refers to the direction towards the center of the core along the radial direction of the core.

[0031] The telescopic writing instrument A includes a shaft cylinder 10, a core 20 housed within the shaft cylinder 10 and having a writing section 21 at its front end, a force-applying component 30 within the shaft cylinder 10 that applies force to the core 20 rearward, a rotor unit 40 within the shaft cylinder 10 that supports the core 20 from the rear side, and a snap-action body 50 that can engage / disengage from the rotor unit 40 from the rear and protrudes from the shaft cylinder 10 to the outside of the shaft cylinder 10 from its rear end. The rotor 42 of the rotor unit 40 advances against the force of the force-applying component 30 and is locked against the inner circumferential surface of the shaft cylinder 10, thereby causing the writing section 21 to protrude from the front end of the shaft cylinder 10 and maintain this protruding state.

[0032] The shaft cylinder 10 is composed of one or more cylindrical components forming an elongated cylindrical shape extending in the front-rear direction. The shaft cylinder 10 in the example figure is a generally cylindrical long strip formed by a pointed cylindrical tip 11, a cylindrical front shaft 12 screwed to the front end of the pointed tip 11, and a cylindrical rear shaft 13 screwed to the front end of the front shaft 12.

[0033] Additionally, in the diagram, symbol 14 is a cylindrical, flexible pen grip fitted into the outer periphery of the front axis 12, and symbol 15 is a pen clip that opens and closes at the rear end of the rear axis 13.

[0034] On the inner circumferential surface of the pointed portion 11, there is an annular stepped portion 11a with a diameter that decreases towards the front to lock the front end of the force-applying component 30.

[0035] On the rear end side of the inner circumferential surface of the rear axle 13, there is a sliding groove 13a that allows the rotor 42 to move forward and backward without rotation, a cam inclined surface and a locking surface (not shown) that allow the rotor 42 to rotate and lock when moving forward. These structures can be, for example, those described in Japanese Patent Application Publication No. 2018-149787.

[0036] Furthermore, on the inner circumferential surface of the rear axle 13, at a position forward of the sliding groove 13a and the cam inclined surface, there is a passing-over-fitting protrusion 13b (see reference) for allowing the rotor unit 40 to pass over and engage with the rear during assembly operations. Figure 5 ).

[0037] The interlocking protrusion 13b is provided in multiple intervals along the circumference of the shaft cylinder.

[0038] Each of the interlocking protrusions 13b is a protrusion with a roughly peak-shaped longitudinal section.

[0039] According to the example in the figure, the core 20 is a ballpoint pen refill, and the ballpoint pen tip, i.e., the writing part 21, is connected to the front end of the long cylindrical ink container 22.

[0040] As another example of the core 20, mechanical pencil leads or leads for electronic input pens (styluses) can also be used.

[0041] On the front end side of the outer peripheral surface of the core 20, a stepped portion 23 with a diameter that tapers forward is provided. The stepped portion 23 abuts against the rear end of the force-applying member 30 and bears the rearward force (elastic force) of the force-applying member 30.

[0042] According to the example in the figure, the force-applying component 30 is an annular elastic component, the front end of which abuts against the stepped portion 11a inside the shaft cylinder 10, and the rear end abuts against the stepped portion 23 of the core 20, thereby applying a force backward to the core 20 and the rotor unit 40.

[0043] Alternatively, as another example of the force-applying component 30, a tension coil spring that pulls the core 20 backward can also be used.

[0044] The rotor unit 40 is integrally formed with a support member 41 that supports the core 20 from the rear side, a rotor 42 that is disposed on the rear side of the support member 41 and can move forward and backward relative to the shaft cylinder 10 and can rotate, and an annular elastic member 43 that springs the support member 41 forward relative to the rotor 42 with a force greater than the force of the force-applying member 30.

[0045] When the rotor unit 40 moves forward against the force applied by the force-applying component 30, it keeps the writing part 21 in a protruding state by being locked inside the shaft cylinder 10.

[0046] The support component 41 is connected to the rotor 42 in a way that allows for free movement and rotation.

[0047] The support member 41 integrally has a thin-walled cylindrical support portion 41a that supports the rear end of the core 20 from the rear, a shaft portion 41b that protrudes rearward from the center side of the rear end face of the support portion 41a, and a plurality of protrusions 41c that protrude rearward from the rear end face of the support portion 41a around the shaft portion 41b.

[0048] The shaft portion 41b is formed as a long shaft that passes through the annular elastic member 43, and has a front sliding portion 41b1 and a rear sliding portion 41b31 (engaging portion) that slide with the rotor 42 in the front-rear direction on its outer peripheral surface.

[0049] The front sliding joint 41b1 is located further forward than the annular elastic member 43 (according to...). Figure 2 The cylindrical surface (located on the left) is appropriately set in the front-to-back direction to allow the rotor 42 to advance and retreat a specified amount.

[0050] The portion of the shaft portion 41b that is rearward from the front sliding portion 41b1 is formed into a smaller diameter via a stepped portion 41b2. The stepped portion 41b2 supports the front end of the annular elastic member 43.

[0051] Furthermore, in the shaft portion 41b, the smaller diameter portion 41b3, which is located rearward of the stepped portion 41b2, is inserted into and passes through the annular elastic member 43. Also, in this smaller diameter portion 41b3, at a position rearward of the annular elastic member 43, a rearward sliding portion 41b31 is provided, which slides in the front-rear direction with the engaging portion 42b1 of the rotor 42.

[0052] The rear sliding portion 41b31 is a recess formed by annularly recessing the outer circumference of the small-diameter portion 41b3 over the entire circumference. The bottom surface of this annular recess is cylindrical.

[0053] The length of the rear sliding part 41b31 in the front-rear direction is set to allow the rotor 42 to move forward and backward by a predetermined amount, so as to function as an engaging part that can engage with the engaging part 42b1 of the rotor 42 by a predetermined amount.

[0054] Furthermore, in the shaft portion 41b, on the outer periphery rearward of the sliding portion 41b31 (engaging portion), a press-in portion 41b32 is provided, which protrudes radially outward in an arc shape to be pressed into the inner peripheral surface of the engaging portion 42b1 (circular hole) and passes through the engaging portion 42b1. Moreover, in the shaft portion 41b, in the portion adjacent to the press-in portion 41b32 in the circumferential direction, a planar gap insertion portion 41b33 is provided that does not contact the inner peripheral surface of the engaging portion 42b1 (circular hole) but penetrates the engaging portion 42b1.

[0055] Two press-in portions 41b32 are provided symmetrically around the central axis. The outer diameter of these press-in portions 41b32 is slightly larger than the inner diameter of the engaging portion 42b1.

[0056] Two gap insertion parts 41b33 are arranged approximately parallel to each other with the central axis as the center.

[0057] In addition, the press-in part 41b32 and the gap insertion part 41b33 may be provided as a single or more than three in the example shown in the figure, or they may be provided as different shapes with the same function.

[0058] Furthermore, the protrusion 41c protrudes rearward from the rear end face of the support portion 41a, and multiple protrusions are provided at intervals in the circumferential direction.

[0059] These multiple protrusions 41c abut against the front end face of the rotor 42 when the support member 41 retracts relative to the rotor 42 (see reference). Figure 3 ).

[0060] The rotor 42 can move forward and backward and fit into the shaft portion 41b without separating. The rotor 42 is formed in a generally cylindrical shape, having a large diameter portion 42a and a small diameter portion 42b that narrows the diameter of the inner and outer circumferential surfaces at the rear end of the large diameter portion 42a.

[0061] The large diameter portion 42a is formed as a cylindrical shape that covers the front sliding portion 41b1 to the annular elastic member 43.

[0062] When the support member 41 moves forward or backward relative to the rotor 42, the front end of the inner peripheral surface of the large diameter portion 42a slides against the outer peripheral surface of the front sliding portion 41b1.

[0063] The small-diameter portion 42b is formed into a generally cylindrical shape, with its inner diameter being smaller than the outer diameter of the annular elastic member 43. At the rear end of the small-diameter portion 42b, a locking portion 42b1 is provided, protruding radially inward in an annular shape. The inner circumferential surface of the locking portion 42b1 is a circular through hole.

[0064] The engaging portion 42b1 is configured such that its length in the front-to-back direction is shorter than the length of the concave portion constituting the rear sliding portion 41b31, so as to slide with the rear sliding portion 41b31 (engaging portion) and move forward and backward by a predetermined amount.

[0065] Furthermore, on the outer periphery of the rotor 42, there are protrusions 42c and cam slopes 42d, etc. The protrusions 42c are fitted into the sliding grooves 13a of the shaft cylinder 10 and extend in the front-rear direction to be guided in the front-rear direction. The cam slopes 42d are provided at the rear end of the protrusions 42c and slide with the cam slopes 51 of the snap-action body 50 or the aforementioned cam slopes (not shown) of the shaft cylinder 10.

[0066] The annular elastic member 43 is housed in the cylindrical space between the shaft portion 41b and the rotor 42. Its front end abuts against the stepped portion 41b2, and its rear end abuts against the front end face of the small diameter portion 42b, thereby repelling the support member 41 forward relative to the rotor 42.

[0067] The annular elastic component 43 in the example diagram is a compression coil spring. The force (elastic force) exerted by the annular elastic component 43 is greater than the force exerted by the force-applying component 30.

[0068] Alternatively, as another example of the annular elastic component 43, it may be made of an elastic material other than a spring, such as a cylindrical rubber.

[0069] The clicker 50 is a rod-shaped component that is clicked from the rear.

[0070] The snap-fit ​​body 50 is formed as a generally bottomed cylindrical shape with an open front end and a closed rear end. A cam slope 51 is formed on its front end for sliding contact with the cam slope 42d of the rotor 42. Furthermore, a snap-fit ​​protrusion 52 is formed on the outer peripheral surface of the snap-fit ​​body 50 to engage with and move in and out of the sliding groove 13a in the shaft cylinder 10.

[0071] In addition, in the example shown in the figure, the snap-action body 50 is composed of two parts: a cylindrical part and a part that closes the rear end of the cylindrical part. However, as another example of the snap-action body 50, it can also be composed of a single part or three or more parts.

[0072] Furthermore, according to Figure 1 (b) shows an example in which the pusher 50 can move freely back and forth in the space behind the rotor unit 40 when the writing part 21 is in the protruding state. However, as another example, it is also possible to use a force-applying component (not shown) or the structure that allows the pusher 50 to move closer to either the front or back side.

[0073] Next, the features and effects of the retractable writing tool A with the above structure will be explained in detail.

[0074] If in the initial state (reference) Figure 1 (a) When the snap-action body 50 is pushed forward, the central core 20 advances a predetermined amount through the action of the snap-action body 50's engaging protrusion 52, the sliding groove 13a in the shaft cylinder 10, the cam inclined surface and locking surface (not shown), the rotor 42's protrusion 42c, and the cam inclined surface 42d, etc., so that the writing part 21 remains in a state protruding from the front end of the shaft cylinder 10 (see reference). Figure 1 (b)). Their functions are, for example, largely the same as those of the structures described in Japanese Patent Application Publication No. 2018-149787.

[0075] Alternatively, the mechanism that causes the rotor unit 40 to advance a predetermined amount and then stop through external operation can be replaced with a mechanism other than the one described above.

[0076] exist Figure 1 (b) In the protruding state of the writing part 21 shown, if the writer holds the shaft 10 to write, the vibration and impact during the writing action will be absorbed by the annular elastic member 43.

[0077] In detail, since the rear end of the core 20 is supported by the front end of the support member 41, if a rearward pressing force greater than the force exerted by the force-applying member 30 is applied to the writing part 21 by pressing the writing part 21 against the writing surface (e.g., paper), the core 20 and the support member 41 will retract against the elastic force of the annular elastic member 43. That is, the dimension W between the rear end of the protrusion 41c of the support member 41 and the front end of the rotor 42 (refer to...) Figure 2 and Figure 3(It becomes smaller.)

[0078] Then, if the pressing force is released, the core 20 and the support member 41 move forward due to the elastic force of the annular elastic member 43. That is, due to this forward movement, the dimension W between the rear end of the protrusion 41c of the support member 41 and the front end of the rotor 42 increases.

[0079] Therefore, even if vibrations in the shaft cylinder are generated, for example, by repeatedly pressing the writing part 21 against the writing surface or moving it away from the writing surface during writing, the elasticity of the annular elastic member 43 that stretches and contracts within the cylindrical space around the shaft part 41b can absorb the vibrations.

[0080] Furthermore, when the vibration is generated, the support member 41 smoothly moves back and forth slightly without loosening by sliding the front sliding part 41b1 and the rear sliding part 41b31 with the rotor 42. Moreover, the support member 41 can rotate freely relative to the rotor 42.

[0081] Therefore, according to the telescopic writing instrument A, the vibration and impact of the core 20 can be effectively suppressed from being transmitted to the shaft cylinder 10 during writing without being affected by the core's eccentricity or deflection, thus providing the writer with a soft writing feel.

[0082] Next, the manufacturing process and effects of the retractable writing instrument A will be explained.

[0083] like Figure 4 As shown, when assembling the rotor unit 40, the annular elastic member 43 is mounted in a ring shape on the shaft portion 41b of the support member 41, and the rotor 42 is mounted in such a way that it covers the shaft portion 41b and the annular elastic member 43.

[0084] In detail, in the shaft portion 41b, the pressing portion 41b32 and the gap insertion portion 41b33 on the front end side protrude to a position further back than the annular elastic member 43, and are pressed into the circular hole-shaped engaging portion 42b1 so that they pass through.

[0085] At this time, the arc-shaped pressing part 41b32 slides against the inner circumferential surface of the engaging part 42b1, but the planar gap insertion part 41b33 does not contact the inner circumferential surface of the engaging part 42b1, so the pressing force is relatively small and the assembly is good.

[0086] Then, after the pressing part 41b32 passes through the engaging part 42b1 to the rear, the rear end of the pressing part 41b32 is engaged with the front end of the circular engaging part 42b1, and the shaft part 41b will not fall off from the engaging part 42b1. That is, the rotor 42 can move forward and backward relative to the support member 41 and cannot be separated.

[0087] Therefore, the rotor unit 40 can be considered as a single unit, including the support member 41, the rotor 42, and the annular elastic member 43.

[0088] Then, as Figure 5 As shown, the rotor unit 40 of the above structure is inserted into the front shaft 12 from the front side, passes over the fitting protrusion 13b, and moves to the rear of the fitting protrusion 13b.

[0089] In detail, because the annular edge 42e on the front end side of the rotor 42 is located further back than the over-fitting protrusion 13b, the rotor unit 40 as a whole, including the rotor 42, will not move forward of the over-fitting protrusion 13b.

[0090] Therefore, even if the rear shaft 13 is removed from the front shaft 12 and the central core 20 is pulled out in order to replace the central core 20, the rotor unit 40 can be prevented from falling off the rear shaft 13.

[0091] In addition, according to the above embodiment, as a particularly preferred method, the support member 41 is engaged with the rotor 42 in a manner that prevents it from being pulled out. However, as another example, it may be configured such that the radially outward protruding press-in portion 41b32 is omitted, thereby separating the rotor 42 and the support member 41 in the axial direction.

[0092] Furthermore, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without changing the spirit of the present invention.

Claims

1. A retractable writing instrument, characterized in that, The telescopic writing instrument comprises a core with a writing section at its front end, a force-applying component that applies force to the core rearward, a support component that supports the core from the rear, a rotor disposed behind the support component and capable of moving forward and backward relative to the cylinder, and an annular elastic component that springs the support component forward relative to the rotor with a force greater than the force of the force-applying component. The telescopic writing instrument is configured such that the rotor advances against the force of the force-applying component and is locked in the cylinder, causing the writing section to protrude and remain in this protruding state. The support component integrally includes a support portion that supports the rear end of the core from the rear and a shaft portion that protrudes rearward from the support portion. The annular elastic component is mounted in a ring shape on the shaft portion. The rotor can be retracted and engaged with the shaft. The rotor is formed as a generally cylindrical portion having a large diameter portion and a small diameter portion with a reduced inner circumferential surface diameter at the rear end of the large diameter portion. The large diameter portion surrounds the annular elastic member, and the small diameter portion supports the rear end of the annular elastic member. The shaft portion passes through the annular elastic member and has an engaging portion located at a rearward position relative to the annular elastic member, which engages with the engaging portion provided on the small diameter portion by a predetermined amount.

2. The retractable writing tool according to claim 1, characterized in that, The engaging part is a through-hole circular hole. The outer periphery, located behind the engaging portion, is provided with: a pressing portion that is pressed into the inner circumferential surface of the circular hole and passes through the circular hole, and a gap insertion portion that is adjacent to the pressing portion in the circumferential direction and passes through the circular hole without contacting the inner circumferential surface of the circular hole.

3. The retractable writing instrument according to claim 1 or 2, characterized in that, The shaft is provided with a sliding joint that slides with the rotor in the front-to-back direction.

4. The retractable writing tool according to claim 3, characterized in that, The sliding joint has a front sliding joint located at a position forward of the annular elastic member and a rear sliding joint located at a position rear of the annular elastic member.

5. The retractable writing instrument according to claim 1 or 2, characterized in that, The support component is rotatably connected to the rotor.

6. The retractable writing instrument according to claim 1 or 2, characterized in that, The rotor can move forward and backward and fit into the shaft without separating. The support component, the rotor, and the annular elastic component constitute an integrated rotor unit.

7. A retractable writing instrument, characterized in that, The telescopic writing instrument comprises a core with a writing section at its front end, a force-applying component that applies force to the core rearward, a support component that supports the core from the rear, a rotor disposed behind the support component and capable of moving forward and backward relative to the cylinder, and an annular elastic component that springs the support component forward relative to the rotor with a force greater than the force of the force-applying component. The telescopic writing instrument is configured such that the rotor advances against the force of the force-applying component and is locked in the cylinder, causing the writing section to protrude and remain in this protruding state. The support component integrally includes a support portion that supports the rear end of the core from the rear and a shaft portion that protrudes rearward from the support portion. The annular elastic component is mounted in a ring shape on the shaft portion. The rotor can be retracted and engaged with the shaft. The shaft is provided with a sliding joint portion that slides with the rotor in the front-to-back direction. The sliding joint has a front sliding joint located at a position forward of the annular elastic member and a rear sliding joint located at a position rear of the annular elastic member.

8. The retractable writing instrument according to claim 7, characterized in that, The rotor is formed as a generally cylindrical portion having a large diameter portion and a small diameter portion with a reduced inner circumferential surface diameter at the rear end of the large diameter portion. The large diameter portion covers the periphery of the annular elastic member, and the small diameter portion supports the rear end of the annular elastic member.

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