Outing organization

Abstract

To provide a retractable mechanism capable of reducing clicking noise while stabilizing retraction action, and further provide a retractable mechanism capable of preventing lubricant from soaking and maintaining slidability of a rotating member by the lubricant for a long period of time.SOLUTION: A retractable mechanism for causing a core body 3 to retract from a tip of a shaft tube 2, the retractable mechanism comprising a plurality of cam teeth 61 and cam grooves 62, a rotating member 7 having a plurality of projections 75 that can engage with the cam teeth 61 or the cam grooves 62 alternately, and a cam member 8 provided with a plurality of different cam projections 83 that rotate the rotating member 7. The projections 75 are provided with a shock absorption unit 76 that absorbs shock caused when the projections 75 and the cam projections 83, and the cam teeth 61 and the cam groove 62 are engaged. Furthermore, the projections 75 are provided with a lubricant holding unit 78 that holds the lubricant.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a retractable mechanism. More specifically, it relates to a retractable mechanism that accommodates a core body in a barrel and operates a knock member provided on the barrel to move the core body in the front-rear direction. [Background Art]

[0002] Conventionally, in a retractable writing instrument in which a writing body is accommodated in a barrel, a knock member provided on the barrel is operated to move the writing body in the front-rear direction, and the pen point of the writing body is extended and retracted from the tip of the writing instrument, a double-knock retractable mechanism is known, which rotates a rotating member inside the barrel by pressing the knock member forward, and alternates engagement between the protrusions of the rotating member and cam teeth or cam grooves on the barrel side, thereby alternately switching the pen point of the writing body between an extended state and a retracted state.

[0003] However, in such a retractable mechanism, during a knocking operation for extending the pen point of the writing body out of the tip opening of the barrel, or during a knocking operation for retracting the pen point of the writing body back into the barrel, an impact noise is generated due to the collision of the rotating cam against the cam groove. FIG. 12 schematically illustrates the extending and retracting operations of conventional and the present retractable mechanisms.

[0004] FIG. 12(a) shows the pen point in a retracted state. In the retracted state of the pen point, the engaging protrusion (84) of the cam member (8) is locked to the locking wall (63) at the rear end of the cam groove (62), the protrusion (75) of the rotating member (7) is engaged with the cam groove (62), and the rear end of the protrusion (75) of the rotating member (7) abuts against the cam protrusion (83). The rotating member (7) is constantly biased rearward by the resilient member (10).

[0005] When the cam member 8 is pressed forward against the rearward bias of the resilient body 10 from the pen tip retracted position, the rib 75 and the engaging projection 84 move forward along the cam groove 62, and as shown in Figure 12(b), the rib 75 is released from its engagement with the cam groove 62. The first impact sound is generated when the rib 75 is released from its engagement with the cam groove 62 and collides with the cam projection 83. At the same time, the rotating member 7 is rotated by the contact between the cam projection 83 and the inclined surface 76, and as shown in Figure 12(c), the rear end of the rib 75 engages with the cam teeth 61, maintaining the pen tip protruding position. At this time, the rib 75 collides with the cam tooth wall surface 61b due to the resilient force of the resilient body 10, and a second impact sound is generated.

[0006] As shown in Figure 12(c), when the cam member 8 is pressed forward against the rearward bias of the resilient body 10 from the pen tip protruding position, the ridge 75 and the engaging projection 84 move forward, and the rotating member 7 rotates due to the contact between the cam projection 83 and the ridge 75, and the engagement between the ridge 75 and the cam teeth 61 is released as shown in Figure 12(d). The third impact sound is generated when the engagement between the ridge 75 and the cam teeth 61 is released and the ridge 75 collides with the cam projection 83. Subsequently, when the forward pressure on the cam member 8 is released, the rotating member 7 and the cam member 8 move backward due to the rearward bias of the resilient body 10, and the ridge 75 engages with the cam groove 62 as shown in Figure 12(e). The fourth impact sound is generated when the ridge 75 engages with the cam groove 62 and the ridge 75 collides with the cam projection 83. Next, the protrusion 75 moves backward along the cam groove 62, and the engaging projection 84 of the cam member 8 engages with the locking wall portion 63 at the rear end of the cam groove 62, resulting in the pen tip being retracted as shown in Figure 12(f).

[0007] As described above, a total of four impact sounds are generated when the pen tip of the retractable writing instrument is extended or retracted. These impact sounds, also known as knocking sounds, serve to confirm the pen tip's position to the user and are not necessarily unpleasant. However, in environments where even slight noises can be easily heard, such as during a meeting, these knocking sounds may be noticeable.

[0008] Patent Document 1 discloses a retractable mechanism that reduces knocking noise by providing a resistance section at the connection between the first cam inclined surface and the contact surface, which reduces the speed of the cam projection sliding on the first cam inclined surface by the elastic force of a spring. The mechanism includes a cam groove comprising a first cam wall extending in the front-rear direction, a first cam inclined surface connected to the side of the first cam wall and against which a cam projection slides, a contact surface connected to the side of the first cam inclined surface and against which a cam projection slides, a second cam wall connected to the side of the second cam inclined surface and against which a cam projection slides, and a vertical groove that forms the gap between the first cam wall and the second cam wall.

[0009] Furthermore, in conventional retractable mechanisms, it is known that lubricants such as silicone oil are applied to improve the sliding properties of the rotating member, as shown in Patent Document 2, for example.

[0010] [Patent Document 1] Japanese Patent Publication No. 2019-010827 [Patent Document 2] Japanese Patent Publication No. 2017-081065 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0011] However, the retractable mechanism described in Patent Document 1 could only reduce the second of the four knocking sounds. Furthermore, the amount of rotation of the rotating member became unstable due to the resistance part, which could lead to unstable retractable operation, such as the rotating member not rotating properly during the retractable operation.

[0012] Furthermore, in the retractable mechanism described in Patent Document 2, even if a lubricant is applied, the lubricant may seep out as the retractable operation is repeated, potentially reducing the sliding properties of the rotating member.

[0013] The present invention solves the aforementioned problems of the conventional invention and provides a retractable mechanism that can reduce all four (four types of) knocking sounds while maintaining stability of the retractable operation. Furthermore, it provides a retractable mechanism that prevents lubricant seepage and can maintain the sliding properties of the rotating member by the lubricant over a long period of time. In this invention, the knocking member side is referred to as the "rear" and the opposite side as the "front". [Means for solving the problem]

[0014] The first invention of this application is a retractable mechanism that houses a core body in a barrel, moves the core body in the front-rear direction by operating a knock member provided on the barrel, and extends and retracts the core body from the tip of the barrel. The retractable mechanism comprises, within the barrel, a plurality of cam teeth and cam grooves extending in the front-rear direction and alternately arranged along the circumferential direction of the inner surface of the barrel; a rotating member rotatably positioned behind the core body and having a plurality of protrusions that can alternately engage with the cam teeth or cam grooves; a knock member provided with a plurality of other cam projections that engage with the protrusions of the rotating member and rotate the rotating member; and a resilient body that biases the core body backward. By pressing the knock member forward against the biasing force of the resilient body, the protrusions alternately engage with the cam teeth or cam grooves, causing the core body to alternately extend or retract. The aforementioned projection is characterized by being provided with an impact-absorbing portion that absorbs the impact that occurs when the projection engages with the cam projection, the cam teeth, and the cam groove.

[0015] The retractable mechanism of the first invention of this application, with the above configuration, can reduce knocking noise by absorbing the impact applied to the protrusion during the retractable operation with the shock-absorbing part. Furthermore, because the shock-absorbing part is provided on the protrusion side, all four knocking noises generated during the retractable operation can be reduced.

[0016] The second invention of this application is that, in the first invention, the protrusion is provided with a recess that reduces the thickness of the protrusion, and it is preferable that the impact absorbing portion has the recess.

[0017] The retractable mechanism of the second invention of this application, with the above configuration, reduces the thickness of the protruding shock-absorbing part by the recess, thereby absorbing the impact applied to the protrusion during the retractable operation and reducing the knocking sound.

[0018] The third invention of the present application is that, in the second invention, the projection is formed in the shape of a rectangular prism extending in the axial direction, the outer surface of the projection is provided with a side wall surface facing radially outward, a long side wall surface and a short side wall surface provided on the circumferential side of the side wall surface and extending in the axial direction, and an inclined surface provided at the axial rear end of the side wall surface and inclined with respect to the axis, and preferably at least one of the outer surfaces of the projection is provided with the recess that opens outward from the outer surface of the projection.

[0019] The retractable mechanism of the third invention of this application, with the above configuration, reduces the thickness of the protruding part by the recess, thereby absorbing the impact applied to the protruding part during the retractable operation and reducing the knocking sound. Furthermore, it reduces the area of ​​the protruding part that collides with other parts during the retractable operation, thereby reducing the knocking sound.

[0020] The fourth invention of this application is preferable in the third invention, wherein the recess is provided in a region excluding both radial ends of the outer surface of the long side wall and the inclined surface, or in a region excluding the radial center, and the region at both radial ends of the outer surface of the long side wall and the inclined surface, or in the radial center, engages with the cam projection, the cam teeth, and the cam groove.

[0021] The retractable mechanism of the fourth invention of this application, with the above configuration, ensures that an area of ​​the outer surface of the protrusion that engages with the cam projection, cam teeth, and cam groove is secured when the pen tip is extended or retracted, and the recess does not affect the retractable operation, thus maintaining the stability of the retractable operation.

[0022] The fifth invention of this application is preferable in the fourth invention, wherein the recess is provided spanning the long side wall surface and the inclined surface.

[0023] With the above configuration, the retractable mechanism according to the fifth invention of the present application can reduce the area of the rear end edge of the protruding strip that collides during the retraction operation, thereby reducing knocking noise.

[0024] The sixth invention of the present application is a retractable mechanism that accommodates a lead body in a barrel, moves the lead body in the front-rear direction by operating a knock member provided on the barrel, and causes the lead body to protrude and retract from the tip end of the barrel, wherein The retractable mechanism comprises, inside the barrel: a plurality of cam teeth and cam grooves that are alternately arranged along the circumferential direction of the inner surface of the barrel and extend in the front-rear direction; a rotating member that is rotatably arranged behind the lead body and has a plurality of protruding strips alternately engageable with the cam teeth or the cam grooves; a cam member engaged with the protruding strips of the rotating member and provided with a plurality of other cam projections for rotating the rotating member; and an elastic body that biases the lead body rearward; by pressing the knock member forward against the biasing force of the elastic body, the protruding strips alternately engage with the cam teeth or the cam grooves, so that the lead body is alternately in a protruding state or a retracted state, A liquid lubricant is applied to an outer surface of each of the protruding strips, and each protruding strip is provided with a lubricant holding portion for holding the lubricant.

[0025] With the above configuration, the retractable mechanism according to the sixth invention of the present application holds the lubricant by the lubricant holding portion, thereby preventing the lubricant from oozing out, and maintaining the sliding performance of the rotating member provided by the lubricant over a long period of time.

[0026] The seventh invention of the present application is characterized in that, in the sixth invention, the protruding strip is formed in a quadrangular prism shape extending in the axial direction, and an outer surface of the protruding strip is provided with: a side wall surface facing radially outward; a long side wall surface and a short side wall surface that are provided on both circumferential sides of the side wall surface and extend in the axial direction; and an inclined surface that is provided axially rearward of the side wall surface and inclined with respect to the axis; a concave portion opening outward from the outer surface of the protruding strip is provided on at least one surface of the outer surface of the protruding strip, and the lubricant holding portion is preferably formed of the concave portion.

[0027] The retractable mechanism of the seventh invention of this application, with the above configuration, prevents the lubricant from seeping out by holding the lubricant in the recess, and can maintain the sliding properties of the rotating member by the lubricant over a long period of time.

[0028] The eighth invention of this application is preferable in the seventh invention, wherein the recess is provided in a region excluding both radial ends of the outer surface of the long side wall and the inclined surface, or in a region excluding the radial center, and the region at both radial ends of the outer surface of the long side wall and the inclined surface, or in the radial center, engages with the cam projection, the cam teeth, and the cam groove.

[0029] The retractable mechanism of the eighth invention of this application, with the above configuration, ensures that the area of ​​the outer surface of the cam projection, cam teeth, and protrusions that slide against the cam projection is secured when the pen tip is extended or retracted, and the recess does not affect the retractable operation, thus maintaining the stability of the retractable operation.

[0030] The ninth invention of this application is preferable in the eighth invention to be provided in which the recess spans the long side wall surface and the inclined surface.

[0031] The retractable mechanism of the ninth invention of this application, with the above configuration, can hold lubricant at the rear edge of the protrusion that collides during the retractable operation, thereby effectively improving the sliding properties of the rotating member by the lubricant. [Effects of the Invention]

[0032] The retractable mechanism of the present invention can reduce all four knocking sounds while maintaining the stability of the retractable operation. Furthermore, it can prevent the seepage of lubricant and maintain the sliding properties of the rotating member provided by the lubricant over a long period of time. [Brief explanation of the drawing]

[0033] [Figure 1] This is a longitudinal cross-sectional view showing the pen tip immersed in an embodiment of the present invention. [Figure 2] This is a longitudinal cross-sectional view showing the pen tip protruding in an embodiment of the present invention. [Figure 3]This is an enlarged longitudinal cross-sectional view of the main part of Figure 1. [Figure 4] Figure 1 is an exploded view showing the main components of the retraction mechanism. [Figure 5] This is a perspective view showing regions X and Y of the rotating member of the present invention. [Figure 6] A perspective view showing an example of a rotating member of the present invention. [Figure 7] A perspective view showing an example of a rotating member of the present invention. [Figure 8] A perspective view showing an example of a rotating member of the present invention. [Figure 9] This is a perspective view showing region Z of the rotating member of the present invention. [Figure 10] This is a perspective view of a rotating member showing a modified example of the recess. [Figure 11] This is a perspective view of a rotating member showing a modified example of the recess. [Figure 12] This is a conceptual diagram showing the positional relationship between the cam groove, the cam member, and the rotating member during the retraction and retraction operation of the conventional and the present invention retraction and retraction mechanisms. [Modes for carrying out the invention]

[0034] Embodiments of the present invention are shown in Figures 1 to 12. In this specification, the present invention will be described using a retractable writing instrument equipped with the retractable mechanism of the present application as an example. In the retractable writing instrument, the core is a writing body equipped with a pen tip.

[0035] As shown in Figure 1, the retractable writing instrument 1 of this embodiment comprises a barrel 2, a writing body 3 housed inside the barrel 2, and a retractable mechanism that allows the pen tip 31 of the writing body 3 to extend and retract freely from a hole at the front end of the barrel 2.

[0036] The writing instrument 3 contains ink dispensed from the pen tip 31. The pen tip 31 may consist of, for example, only a metal ballpoint pen with a ball rotatably held at its front end, or a synthetic resin pen tip holder that holds the rear outer surface of the ballpoint pen tip.

[0037] ·Shaft cylinder The shaft cylinder 2 consists of a front shaft 4, an intermediate shaft 5 connected to the rear end of the front shaft 4, and a rear shaft 6 connected to the rear end of the intermediate shaft 5.

[0038] The front shaft 4 is a tapered cylindrical body made of metal or synthetic resin. A female thread is formed on the inner surface of the rear end opening of the front shaft 4.

[0039] The intermediate shaft 5 is a cylindrical body made of synthetic resin with open ends. The outer surface of the front end of the intermediate shaft 5 has a male threaded portion that can be screwed into the female threaded portion of the front shaft 4. The outer surface of the rear end of the intermediate shaft 5 has a male threaded portion that can be screwed into the female threaded portion of the rear shaft 6. A grip portion 51 made of an elastic material is formed on the outer surface of the intermediate part of the intermediate shaft 5. The grip portion 51 is provided on the outer surface of the front shaft 4 by two-color molding or by attaching a separate component.

[0040] The rear shaft 6 is a cylindrical body made of synthetic resin with open ends. A female thread is formed on the inner surface of the front end opening of the rear shaft 6, which can be screwed into the male thread on the outer surface of the rear end of the intermediate shaft 5. Multiple (for example, four) cam teeth 61 and cam grooves 62 extending in the front-rear direction are integrally formed on the rear inner surface of the rear shaft 6. The cam teeth 61 and cam grooves 62 are arranged alternately along the circumferential direction. The cam teeth 61 have discontinuously arranged cam tooth inclined surfaces 61a that are inclined with respect to the axis, and cam tooth wall surfaces 61b extending in the axial direction are provided between each cam tooth inclined surface 61a. In addition, a cam guide groove 62a extending in the front-rear direction is formed on each cam tooth 61. The cam guide grooves 62a and the cam grooves 62 are arranged alternately at equal intervals along the circumferential direction. A locking wall portion 63 is integrally formed at the rear end of the cam groove 62.

[0041] ·Appearance mechanism As shown in Figures 1 to 4, the retractable mechanism comprises cam teeth 61 and cam grooves 62 formed on the inner surface of the barrel 2 (inner surface of the rear barrel 6), a rotating member 7 that engages with the cam teeth 61 or cam grooves 62 and contacts the rear end of the writing body 3, a cam member 8 that engages with the rotating member 7 and the cam grooves 62, a knock member 9 connected to the cam member 8, and a resilient body 10 (e.g., a compression coil spring) housed in the barrel 2 and biasing the writing body 3 backward. The retractable mechanism of this embodiment is a double-knock type in which both the pen tip extension operation and the pen tip retraction operation press the knock member 9 forward.

[0042] Rotating member The rotating member 7 is a cylindrical body with both ends open. The rotating member 7 is made of synthetic resin. Among synthetic resins, polyacetal is particularly suitable for the rotating member 7 because of its high wear resistance and sliding properties.

[0043] An annular flange portion 71 is formed at the front end of the rotating member 7. A large-diameter cylindrical portion 72 is formed behind the annular flange portion 71 of the rotating member 7. A small-diameter cylindrical portion 73 is formed behind the large-diameter cylindrical portion 72 of the rotating member 7, having an outer diameter smaller than the outer diameter of the large-diameter cylindrical portion 72. The small-diameter cylindrical portion 73 is loosely inserted into the inner surface of the front end of the cam member 8 (the inner surface of the large-diameter front portion 81). A stepped portion 74 is formed on the inner surface of the front end of the rotating member 7. The rear end of the cursive writing body 3 abuts against the stepped portion 74. On the outer surface of the large-diameter cylindrical portion 72 (behind the annular flange portion 71 and in front of the small-diameter cylindrical portion 73), a plurality (for example, four) of protrusions 75 extending in the front-rear direction and capable of engaging with the cam groove 62 are formed at equal intervals in the circumferential direction.

[0044] The projection 75 is a rectangular prism shape extending in the axial direction. The outer surface of the projection 75 has a long side wall surface 75a extending in the axial direction, an inclined surface 75b inclined with respect to the axis, a side wall surface 75c facing radially outward, and a short side wall surface 75d extending in the axial direction. The long side wall surface 75a and the short side wall surface 75d are provided on both sides of the side wall surface 75c in the circumferential direction. The inclined surface 75b is connected to the rear end of the side wall surface 75c, the rear end of the long side wall portion 75a, and the rear end of the short side wall surface 75d. The long side wall surface 75a and the inclined surface 75b are engageable with the cam teeth 61 and the cam projection 83.

[0045] Cam member The cam member 8 is a bottomed cylindrical body made of synthetic resin, with an open front end and a closed rear end. The cam member 8 comprises a large-diameter front portion 81 and a small-diameter rear portion 82 integrally connected to the rear of the front portion 81 and having an outer diameter smaller than the outer diameter of the front portion 81. Multiple (e.g., 8) sawtooth-shaped (mountain-shaped) cam protrusions 83 are arranged circumferentially on the front end surface of the cam member 8 (the front end surface of the large-diameter front portion 81). Multiple (e.g., 8) engagement protrusions 84 are formed on the outer surface of the front end of the cam member 8 (the outer surface of the front end of the large-diameter front portion 81), distributed along the circumferential direction. Each of the engagement protrusions 84 is provided behind each of the cam protrusions 83. When the pen tip is retracted, the engagement protrusions 84 are locked to the locking wall portion 63 in the front-rear direction. The engagement protrusions 84 and the cam groove 62 are engaged with a amount of play in the rotational direction. Furthermore, the engaging projection 84 and the cam guide groove 62a are engaged with a amount of play in the rotational direction.

[0046] • Knockout member The knocking member 9 comprises a clip 91 extending in the front-rear direction and a bottomed cylindrical portion 92 integrally connected to the clip 91, and is formed from synthetic resin.

[0047] The small-diameter rear portion 82 of the cam member 8 is inserted into the cylindrical portion 92, and the inner surface of the cylindrical portion 92 and the outer surface of the small-diameter rear portion 82 are connected by fitting.

[0048] • Impact absorbing part The protrusion 75 is provided with an impact-absorbing section 76 to absorb the impact of the protrusion 75. In order to absorb the impact when the protrusion 75 collides, it is preferable to provide the impact-absorbing section 76 at a position on the protrusion 75 where it collides with other members. That is, it is preferable to provide the impact-absorbing section 76 at least within the axial region H at the rear end of the protrusion 75 where the protrusion 75 and the cam tooth wall surface 61b collide (see Figure 12(c)).

[0049] As shown in Figure 5, the shock-absorbing portion 76 is provided with a recess 77 that opens outward from the outer surface of the protrusion 75. By providing the recess 77, the thickness of a portion of the protrusion 75 is reduced, improving the shock absorption of the protrusion 75, and reducing knocking noise by absorbing the impact during collision. The thickness of the protrusion 75 refers to the thickness of the synthetic resin that constitutes the protrusion 75. Furthermore, by providing the recess 77, the thickness of the protrusion 75 can be reduced, preventing sink marks when molding the rotating member 7. It is sufficient for the shock absorption of the protrusion 75 to be improved by the shock-absorbing portion 76, and other options for the shock-absorbing portion 76 include groups of minute protrusions or a textured surface. Alternatively, only the shock-absorbing portion 76 may be replaced with a different material (not limited to synthetic resin) that has high shock absorption. For example, shock absorption can be imparted to the protrusion 75 by forming the entire rotating member 7 or the shock-absorbing portion 76 with a lower-density synthetic resin such as polypropylene or polyethylene.

[0050] As shown in Figures 3 and 5, the recess 77 is provided in the region excluding regions X and Y (hatched areas in Figures 3 and 5) at both radial ends of the protrusion 75. As shown in Figure 3, region X is the outer surface region of the long side wall surface 75a and inclined surface 75b radially inward of the protrusion 75. Region Y is the outer surface region of the long side wall surface 75a and inclined surface 75b radially outward of the protrusion 75. Region X of the protrusion 75 can engage with the cam projection 83, and region Y can engage with the cam teeth 61 and cam groove 62. By leaving at least regions X and Y in the protrusion 75, the regions of the long side wall surface 75a and inclined surface 75b that slide against the cam teeth 61 and cam projection 83 during pen tip extension and retraction operations can be secured, and the influence of the recess 77 on the stability of the extension and retraction operation can be avoided.

[0051] At least one of the long side wall surface 75a, inclined surface 75b, side wall surface 75c, and short side wall surface 75d is provided with a recess 77 that opens outward from the outer surface. Depending on the location where the recess 77 is provided, it is referred to as the long side wall recess 77a, inclined surface recess 77b, side wall recess 77c, and short side wall recess 77d. As shown in Figure 6, the recess 77 may be provided simultaneously on each of the long side wall surface 75a, inclined surface 75b, side wall surface 75c, and short side wall surface 75d, or it may be provided on any of the surfaces individually.

[0052] In particular, when recesses 77 are provided on the long side wall surface 75a and the inclined surface 75b, the contact area between the protrusion 75 and the cam teeth 61 and cam projection 83 can be reduced, thereby effectively reducing knocking noise.

[0053] The number, opening shape, and depth of the recesses 77 can be set arbitrarily. By rounding the corners of the openings of the recesses 77, stress concentration at the corners can be avoided, and the shock-absorbing section 76 can be provided while maintaining the strength of the protrusions 75. Furthermore, the greater the depth of the recesses 77, the larger the area where the thickness of the protrusions 75 is thin, thereby improving the shock absorption performance of the shock-absorbing section 76.

[0054] The recess 77 may be provided through the ridge 75. As shown in Figure 7, the recess 77 may be provided simultaneously on each of the long side wall surface 75a, inclined surface 75b, side wall surface 75c, and short side wall surface 75d, or it may be provided on any of the surfaces individually. The direction in which the recess 77 penetrates can be arbitrarily set to the circumferential direction, axial direction, radial direction, etc. In particular, if the inclined surface recess 77b penetrates the ridge 75 in the axial direction, or if the side wall surface recess 77c penetrates the ridge 75 in the radial direction, the ridge 75 can be made hollow, and the shock absorption performance of the shock absorption part 76 can be further improved.

[0055] The recesses 77 may be provided in the shape of vertical grooves. As shown in Figure 8, the recesses 77 may be provided simultaneously on each of the long side wall surface 75a, the inclined surface 75b, the side wall surface 75c, and the short side wall surface 75d, or they may be provided individually on any of the surfaces. In particular, when the recesses 77 are provided on the long side wall surface 75a and the inclined surface 75b, the rear end of the protrusion 75 is cut out by the recesses 77. Because the rear end of the protrusion 75 is cut out, the thickness of the rear end of the protrusion 75 is reduced, improving its impact absorption.

[0056] The recess 77 may be provided on the inner surface of the protrusion 75, thereby reducing the thickness of the protrusion 75 from the inside. By providing the recess 77 on the inner surface of the protrusion 75, the impact absorption performance of the impact absorption part 76 can be improved while maintaining the appearance of the conventional rotating member 7.

[0057] As shown in Figure 9, the recess 77 may be provided in the region of the protrusion 75 excluding the region Z in the radial center (hatched portion in Figure 9). Region Z is the outer surface region of the long side wall surface 75a and the inclined surface 75b in the radial center of the protrusion 75. The region Z of the protrusion 75 can engage with the cam projection 83, the cam teeth 61, and the cam groove 62. By leaving at least region Z in the protrusion 75, the region of the long side wall surface 75a and the inclined surface 75b that slides against the cam teeth 61 and the cam projection 83 during the pen tip extension and retraction operation can be secured, and the influence of the recess 77 on the stability of the extension and retraction operation can be avoided.

[0058] Lubricant retention section To ensure smooth retraction and extension, the rotating member 7 may be coated with a liquid (semi-solid) lubricant such as silicone oil or grease. In this case, by providing a lubricant retaining portion 78 on the protrusion 75 to hold the lubricant, seepage of the lubricant can be prevented, and the sliding properties of the rotating member 7 due to the lubricant can be maintained for a long period of time. To improve the lubricity of the protrusion 75, it is preferable to provide the lubricant retaining portion 78 at a position on the protrusion 75 where it collides with other members. That is, it is preferable to provide the lubricant retaining portion 78 at least within the axial region H at the rear end of the protrusion 75 where the protrusion 75 and the cam tooth wall surface 61b collide (see Figure 12(c)).

[0059] One possible form of the lubricant-holding portion 78 is a recess 77. The recess 77 is similar in form to that of the shock-absorbing portion 76 and is provided as shown in Figures 5 to 9. The recess 77 can serve as both the shock-absorbing portion 76 and the lubricant-holding portion 78. It is sufficient for the lubricant to be held in the ridge 75 by the lubricant-holding portion 78, and other forms of lubricant-holding portion 78 include groups of minute protrusions or a textured surface. Furthermore, the lubricant-holding portion 78 alone may be replaced with a different material that has high liquid-holding capacity.

[0060] The opening shape of the recess 77 may be tapered, with the width narrowing towards one end. For example, as shown in Figure 10, by tapering the long-side wall recess 77a, the capillary force of the recess 77 can be increased, thereby improving the lubricant retention capacity.

[0061] The recesses 77 may be arranged in a comb-like pattern. For example, as shown in Figure 11, by arranging the long-side wall recesses 77a and the inclined surface recesses 77b in a comb-like pattern, the capillary force of the recesses 77 can be increased, thereby improving the lubricant retention capacity.

[0062] The retractable mechanism of the present invention can be applied not only to retractable writing instruments, but also to retractable styluses used for touch panel input, retractable erasers, and the like.

[0063] The retractable mechanism of this embodiment houses the core body 3 inside the barrel 2, and moves the core body 3 in the front-back direction by operating a knock member 9 provided on the barrel 2, thereby extending and retracting the core body 3 from the tip of the barrel 2. The aforementioned retractable mechanism comprises a plurality of cam teeth 61 and cam grooves 62 extending in the front-rear direction and alternately arranged along the circumferential direction of the inner surface of the shaft 2; a rotating member 7 rotatably positioned behind the core body 3 and having a plurality of protrusions 75 that can alternately engage with the cam teeth 61 or cam grooves 62; a knock member 9 provided with a plurality of other cam projections 83 that engage with the protrusions 75 of the rotating member 7 and rotate the rotating member 7; and a resilient body 10 that biases the core body 3 backward. By pressing the knock member 9 forward against the biasing force of the resilient body 10, the protrusions 75 alternately engage with the cam teeth 61 or cam grooves 62, causing the core body 3 to alternately extend or retract. The projection 75 is provided with an impact-absorbing section 76 that absorbs the impact when the projection 75 engages with the cam projection 83, cam teeth 61, and cam groove 62. The impact-absorbing section 76 absorbs the impact applied to the projection during the retraction and extension operation, thereby reducing the knocking sound. Furthermore, because the impact-absorbing section 76 is provided on the projection 75, all four knocking sounds that occur during the retraction and extension operation can be reduced.

[0064] In this embodiment, the retractable mechanism is provided with a recess 77 on the protruding ridge 75 that reduces the thickness of the protruding ridge 75, and the shock-absorbing part 76 also has a recess 77. As a result, the thickness of the shock-absorbing part 76 of the protruding ridge 75 is reduced by the recess 77, thereby absorbing the impact applied to the protruding ridge 75 during the retractable operation and reducing the knocking sound.

[0065] In this embodiment, the retractable mechanism has a projection 75 formed in the shape of a rectangular prism extending in the axial direction. The outer surface of the projection 75 has a side wall surface 75c facing radially outward, a long side wall surface 75a and a short side wall surface 75d provided on the circumferential side of the side wall surface 75c and extending in the axial direction, and an inclined surface 75b provided at the axial rear end of the side wall surface 75c and inclined with respect to the axis. At least one of the outer surfaces of the projection 75 is provided with a recess 77 that opens outward from the outer surface of the projection 75. The thickness of the projection is reduced by the recess 77, which allows for the absorption of impact applied to the projection during the retractable operation, thereby reducing knocking noise while maintaining the stability of the retractable operation. In addition, the area of ​​the projection 75 that collides with other members during the retractable operation is reduced, thereby reducing knocking noise.

[0066] In this embodiment, the retractable mechanism has recesses 77 provided in areas excluding the radial ends X and Y of the outer surface of the long side wall surface 75a and the inclined surface 75b, or in areas excluding the radial center Z. The cam projection 83, cam teeth 61, and cam groove 62 engage with the radial ends X and Y of the outer surface of the long side wall surface 75a and the inclined surface 75b, or the radial center Z. This ensures that an area of ​​the outer surface of the protrusion 75 that engages with the cam projection 83, cam teeth 61, and cam groove 62 is secured during the pen tip retraction operation, and the recesses 77 do not affect the retraction operation, thus maintaining the stability of the retraction operation.

[0067] In this embodiment, the retractable mechanism has a recess 77 that spans both the long side wall surface 75a and the inclined surface 75b, thereby reducing the area of ​​the rear edge of the protrusion 75 that collides during the retractable operation and reducing knocking noise.

[0068] The retractable mechanism of this embodiment houses the core body 3 inside the barrel 2, and moves the core body 3 in the front-back direction by operating a knock member 9 provided on the barrel 2, thereby extending and retracting the core body 3 from the tip of the barrel 2. The aforementioned retractable mechanism comprises a plurality of cam teeth 61 and cam grooves 62 extending in the front-rear direction and alternately arranged along the circumferential direction of the inner surface of the shaft 2; a rotating member 7 rotatably positioned behind the core body 3 and having a plurality of protrusions 75 that can alternately engage with the cam teeth 61 or cam grooves 62; a knock member 9 provided with a plurality of other cam projections 83 that engage with the protrusions 75 of the rotating member 7 and rotate the rotating member 7; and a resilient body 10 that biases the core body 3 backward. By pressing the knock member 9 forward against the biasing force of the resilient body 10, the protrusions 75 alternately engage with the cam teeth 61 or cam grooves 62, causing the core body 3 to alternately extend or retract. A liquid lubricant is applied to the outer surface of the protrusion 75, and the protrusion 75 is provided with a lubricant retaining portion 78 for holding the lubricant. By holding the lubricant with the lubricant retaining portion 78, the seepage of the lubricant is prevented, and the sliding properties of the rotating member 7 can be maintained by the lubricant.

[0069] In this embodiment, the retractable mechanism has a projection 75 formed in the shape of a rectangular prism extending in the axial direction. The outer surface of the projection 75 has a side wall surface 75c facing radially outward, a long side wall surface 75a and a short side wall surface 75d provided on the circumferential side of the side wall surface 75c and extending in the axial direction, and an inclined surface 75b provided at the axial rear end of the side wall surface 75c and inclined with respect to the axis. At least one of the outer surfaces of the projection 75 is provided with a recess 77 that opens outward from the outer surface of the projection 75. The lubricant holding portion 78 consists of the recess 77, and by holding the lubricant in the recess 77, the seepage of the lubricant is prevented, and the sliding properties of the rotating member 7 due to the lubricant can be maintained for a long period of time.

[0070] In this embodiment, the retractable mechanism has recesses 77 provided in areas excluding the radial ends X and Y of the outer surface of the long side wall surface 75a and the inclined surface 75b, or in areas excluding the radial center Z. The cam projection 83, cam teeth 61, and cam groove 62 engage with the radial ends X and Y of the outer surface of the long side wall surface 75a and the inclined surface 75b, or the radial center Z. This ensures that an area of ​​the outer surface of the protrusion 75 that engages with the cam projection 83, cam teeth 61, and cam groove 62 is secured during the pen tip retraction operation, and the recesses 77 do not affect the retraction operation, thus maintaining the stability of the retraction operation.

[0071] In this embodiment, the retractable mechanism has a recess 77 that spans both the long side wall surface 75a and the inclined surface 75b. This allows the lubricant to be held at the rear edge of the protrusion 75 that collides with the retractable mechanism during operation, thereby effectively improving the sliding properties of the rotating member 7 due to the lubricant. [Explanation of symbols]

[0072] 1 Removable writing instrument 2 shaft cylinder 3 Cursive (core) 31 nibs 4 Front axle 5 Intermediate axis 51 Grip section 6 rear axle 61 cam teeth 61a Cam tooth inclined surface 61b Cam tooth wall 62 cam groove 62a Cam guide groove 63 Locking wall section 7 Rotating Member 71 Annular flange 72 Large diameter cylindrical section 73 Small diameter cylinder part 74 Step part 75 protrusion 75a Long side wall 75b Slope 75c Side wall 75d Short side wall 76 Shock-absorbing part 77 recess 77a Long side wall recess 77b Inclined surface recess 77c Side wall recess 77d Short side wall recess 78 Lubricant holding section 8 Cam member 81 Front 82 Rear 83 Cam protrusion 84 Engagement protrusion 9 Knock Member 91 clips 92 Cylindrical part 10 projectiles Outer surface area of ​​the long side wall surface 75a and inclined surface 75b in the radially inward direction of the X projection 75 Outer surface area of ​​the long side wall surface 75a and inclined surface 75b radially outward of the Y-shaped projection 75 Outer surface area of ​​the long side wall surface 75a and inclined surface 75b at the radial center of the Z projection 75 The axial region at the rear end of the projection 75 where the projection 75 and the cam tooth wall surface 61b collide.

Claims

1. A retractable mechanism that houses a core body inside a barrel, moves the core body in the front-to-back direction by operating a knock member provided on the barrel, and extends and retracts the core body from the tip of the barrel, The retractable mechanism comprises, within the barrel, a plurality of cam teeth and cam grooves extending in the front-rear direction and alternately arranged along the circumferential direction of the inner surface of the barrel; a rotating member rotatably positioned behind the core body and having a plurality of protrusions that can alternately engage with the cam teeth or cam grooves; a knock member provided with a plurality of other cam projections that engage with the protrusions of the rotating member and rotate the rotating member; and a resilient body that biases the core body backward. By pressing the knock member forward against the biasing force of the resilient body, the protrusions alternately engage with the cam teeth or cam grooves, causing the core body to alternately extend or retract. The aforementioned protrusion is provided with an impact-absorbing portion that absorbs the impact when the protrusion engages with the cam projection, the cam teeth, and the cam groove. The aforementioned protrusion is provided with a recess that reduces the thickness of the protrusion, and the impact absorbing portion has the recess. The projection is formed in the shape of a rectangular prism extending in the axial direction, and the outer surface of the projection has a side wall surface facing radially outward, a long side wall surface and a short side wall surface provided on the circumferential side of the side wall surface and extending in the axial direction, and an inclined surface provided at the axial rear end of the side wall surface and inclined with respect to the axis, and at least one of the outer surfaces of the projection is provided with the recess that opens outward from the outer surface of the projection. The recess is provided in an area excluding both radial ends of the outer surface of the long side wall and the inclined surface, or in an area excluding the radial center, and the cam projection, the cam teeth, and the cam groove engage with the area at both radial ends of the outer surface of the long side wall and the inclined surface, or the area in the radial center.

2. The retractable mechanism according to claim 1, characterized in that the recess is provided spanning the long side wall surface and the inclined surface.

Images