JP2024000380A - Retractable writing instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retractable writing instrument which prevents rattling of a tip in writing and provides stable writing feeling, is unsusceptible to actuation failure, and can keep a smoothly protruding operation for an extended period.

SOLUTION: A retractable writing instrument includes a barrel having an opening in a front end thereof, a tip holder which can move in an axial direction of the barrel, a tip which can retract along with a movement of the tip holder, an annular member which is fitted in an inner periphery of the opening of the barrel with a play therebetween and can move in the axial direction, and an elastic member which can connect the tip holder and the annular member to each other with their relative movement allowed. An abutment surface tapered toward a front end is formed in at least part of an outer periphery of the annular member. A cutout is formed in part of the annular member. The annular member is configured such that when receiving a load on the abutment surface, an inner diameter of the annular member is reduced. A surface in the rear of a protrusion part of an inner surface of the barrel is perpendicular to the axial direction, and comes into abutment contact with a flange part in an outer periphery of the annular member to define a movement limit of a front side of the annular member.

SELECTED DRAWING: Figure 7

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a retractable writing instrument in which a tip can be ejected and retracted from an opening in a barrel as a tip holder moves.

Patent Document 1 discloses a device for preventing shaking of a writing tip. The device is constructed such that a groove is provided at an appropriate position on the writing tip, and an elastic O-ring having an outer diameter approximately equal to the inner diameter of the tip of the barrel is fitted into the groove. According to this device, it is possible to prevent the rattling sound that occurs when the writing tip comes into contact with the tip hole of the barrel tip when writing in pencil-type and knock-type writing instruments.

Patent Document 2 also discloses a writing tip shake prevention device. The structure of the device is such that an elastic ring having an inner diameter slightly smaller than the outer diameter of the writing tip is engaged with a locking step provided in the tip of the barrel. According to this device, since the elastic ring locks the writing tip, even if there is a gap between the inner diameter of the tip of the barrel and the writing tip, it is possible to prevent wobbling during writing.

Patent Document 3 discloses a writing instrument that slides in the front-rear direction with respect to a barrel and draws out a writing part of a cursive from an opening of the barrel. An annular member is disposed around the outer periphery of the tip of the writing body, and a substantially spherical inner surface with which the annular member comes into contact is formed on the inner surface around the opening at the tip of the shaft cylinder where the writing part appears and retracts. The annular member is fixed to the writing body via a spring and is urged forward. When the writing portion is extended, the annular member is brought into close contact with the inner surface of the tip of the barrel due to the elastic force of the spring. This can prevent wobbling when writing.

Patent Document 4 by the present applicant discloses four types of configurations as a retractable writing instrument that prevents the tip from rattling.

Furthermore, Patent Document 5 by the present applicant discloses the configuration of a retractable writing instrument that improves the problems of Patent Documents 1 to 4 (However, Patent Document 5 (and the content disclosed therein) is not applicable to the present application. (Not published at the time of filing).

FIG. 8 is a schematic vertical cross-sectional view of the retractable writing instrument 10 in the first embodiment of Patent Document 5, showing a state in which the tip 14 (writing body) does not protrude. FIG. 9 is an enlarged vertical cross-sectional view of the tip portion of the retractable writing instrument 10 of this embodiment.

10(a) is a perspective view of the annular member 15 of the retractable writing instrument 10 of this embodiment, and FIG. 10(b) is a plan view of the annular member 15 of FIG. 10(a). 10(c) is a side view of the annular member 15 in FIG. 10(a), FIG. 10(d) is a bottom view of the annular member 15 in FIG. 10(a), and FIG. 10(e) is a side view of the annular member 15 in FIG. 10(c) is a cross-sectional view taken along line AA, FIG. 10(f) is a front view (view from the tip side) of the annular member of FIG. 10(a), and FIG. 10(g) is It is a back view of the annular member of Fig.10 (a).

Furthermore, FIG. 11 is a schematic diagram showing a state in which the tip 14 is in contact with the annular member 15 in the process of protruding the tip 14 in the retractable writing instrument 10 of this embodiment, and FIG. In the retractable writing instrument 10, it is a schematic diagram showing a state in which the tip 14 is most protruded in the process of the protruding operation of the tip 14. FIG. FIG. 3 is a schematic diagram showing a state in which the chip 14 protrudes after the above-mentioned operation.

A retractable writing instrument 10 according to the first embodiment shown in FIGS. 8 to 13 includes a cylindrical barrel 11 having an opening at the front end. As shown in FIGS. 8 to 10, in this embodiment, the shaft tube 11 has a rear portion 11r and a front portion 11m. The rear part 11r and the front part 11m are removably fixed by screw connection (threaded engagement). However, the rear portion 11r and the front portion 11m may be fixed by fitting or may be formed integrally.

A chip holder 13 that is movable in the axial direction of the shaft cylinder 11 is housed inside the shaft cylinder 11 . A tip 14, which is a writing script, is fixed to the front end of the tip holder 13. As the chip holder 13 moves, the chip 14 can move in and out of the opening of the shaft tube 11, as shown in FIGS. 11 to 13.

As shown in FIG. 9, the tip holder 13 has a base end portion 13a, a first collar portion 13b, and a second collar portion 13c in this order from the base end side to the distal end side. The base end portion 13a and the first collar portion 13b are both cylindrical portions in this embodiment, and the second collar portion 13c is a truncated conical portion in this embodiment, and their cross-sectional diameters are The mutual relationship is base end portion 13a>first collar portion 13b>second collar portion 13c.

In this embodiment, as shown in FIG. 9, an annular member 15 that is movable in the axial direction of the shaft tube 11 is loosely fitted on the inner periphery of the opening of the shaft tube 11. The front end of the annular member 15 is located further forward than the front end of the shaft tube 11. The rear side of the annular member 15 has an enlarged outer diameter and inner diameter, and covers the tip 14 (with a diameter of 2.5 mm) without contacting it.

Further, the annular member 15 is fixed to the front end of a coil spring 16 (an example of an elastic member). The coil spring 16 surrounds the second collar part 13c of the chip holder 13 and the chip 14 in a loosely fitted state (with a gap), and the rear end of the coil spring 16 is constantly pressed by the base end 13a of the chip holder 13. Yes (not fixed). Thereby, the coil spring 16 connects the chip holder 13 and the annular member 15 so that they can move relative to each other. As shown in FIGS. 11 to 13, as the tip holder 13 moves and the coil spring 16 expands and contracts, the annular member 15 becomes movable relative to the shaft tube 11 in the axial direction of the shaft tube 11. ing.

The annular member 15 is made of resin (for example, polyacetal, polypropylene, polyethylene) or metal (for example, brass).

Further, as shown in FIGS. 10(a) to 10(g), the outer circumferential surface of the annular member 15 has a small outer diameter cylindrical surface 15a (φ3.6 mm, axial length 1.6 mm) from the front side. , a first truncated conical outer surface 15b (axial length 1.1 mm) as a tapered contact surface, a middle outer diameter cylindrical surface 15c (φ4.85 mm, axial length 1.5 mm), and a tapered A second truncated conical outer surface 15d (axial length 1.6 mm) as a contact surface, a first large outer diameter cylindrical surface 15e (φ6.3 mm, axial length 0.8 mm), and a tapered abutment. A third truncated conical outer surface 15f (axial length 0.4 mm) as a contact surface and a second large outer diameter cylindrical surface 15g (φ6.6 mm, axial length 3.3 mm) are provided in this order. It is being

Further, as shown in FIG. 10(e), the inner peripheral surface of the annular member 15 includes, from the front side, a small inner diameter cylindrical surface 15ia (φ3.0 mm, axial length 2 mm) and a first truncated conical inner surface 15ib. (axial length 0.5mm), medium inner diameter cylindrical surface 15ic (φ3.6mm, axial length 3.9mm), second truncated conical inner surface 15id (axial length 0.4mm), and four surfaces. The brushing part 15ie (inscribed circle φ5.28 mm, axial length 0.9 mm), the large inner diameter cylindrical surface 15if (φ5.43 mm, axial length 2.1 mm), and the third truncated conical inner surface 15ig (axis direction length 0.4 mm) are provided in this order. As shown in FIG. 9, in this embodiment, the front end of the coil spring 16 is fixed (fitted and fixed) on the four-sided sweeping part 15ie.

Further, the annular member 15 of this embodiment is provided with three slits 15s as cutouts. As shown in FIGS. 10(a) to 10(g), the three slits 15s are arranged at equal intervals (every 120 degrees) in the circumferential direction of the annular member 15. Each of the three slits 15s has a width of 0.8 mm and extends in the axial direction of the annular member 15 from the front end to approximately the center of the second truncated conical outer surface 15d (maximum axial length 5.5 mm). ).

As a result, when a load is applied to the first frustoconical outer surface 15b (abutting surface), the inner diameter of the annular member 15 is flexibly reduced, and when the load is released, the annular member The inner diameter of 15 is designed to return elastically.

On the other hand, as shown in FIG. 9, FIG. 12, or FIG. 13, the inner peripheral surface near the opening of the shaft tube 11 has a small inner diameter cylindrical surface 11ia (φ3.7 mm, axial length 1.2 mm) from the front side. , a first truncated conical inner surface 11ib (axial length 1.1 mm) as a tapered guide surface, a medium inner diameter cylindrical surface 11ic (φ4.95 mm, axial length 1.3 mm), and a tapered shape. a second truncated conical inner surface 11id (axial length 1.7 mm) as a guide surface, a first large inner diameter cylindrical surface 11ie (φ6.5 mm, axial length 0.8 mm), and a third truncated conical an inner surface 11if (axial length 0.3 mm), a second large inner diameter cylindrical surface 11ig (φ6.7 mm, axial length 4.2 mm), and an annular projection 11ih as a regulating element (minimum aperture diameter φ6.5 mm) and are provided in that order.

As a result, the first truncated conical outer surface 15b (contact surface), the first truncated conical inner surface 11ib and the second truncated conical inner surface 11id (guide surface) move toward the front end side of the chip holder 13, respectively. ) to receive the load.

Note that the coil spring 16 of this embodiment is configured such that when the tip 14 is retracted (e.g., a sliding operation of the operating section provided on the side of the writing instrument to release the locking mechanism that maintains the protruding state of the tip 14), the tip 14 is retracted. It also has a function of automatically recessing the holder 13. That is, the coil spring 16 functions as a so-called knock spring. (The operating load is about 50 gf to 300 gf (about 0.49 N to 2.94 N). For example, the operating load when not in use (Figure 9) is 68 gf, the load at full stroke (Figure 12) is 288 gf, The operating load from the time (Fig. 13) is 227gf. Also, the spring constant is 0.23N/mm).

The retractable writing instrument 10 configured as described above operates as follows.

When not in use, the tip 14 (cursive writing) of the retractable writing instrument 10 is in a retracted state as shown in FIGS. 8 and 9. At this time, the axial length of the coil spring 16 is 17 mm, the annular member 15 is not reduced in diameter, and the small inner diameter cylindrical surface 15ia of the annular member 15 remains φ3.0 (>the outer diameter of the tip 14). be.

Then, when the tip is operated to protrude (for example, a sliding operation of the operating section provided on the side surface of the writing instrument) is performed, the tip 14 (writing body) of the retractable writing instrument 10 reaches the state shown in FIG. 11.

In the state shown in FIG. 11, the second collar portion 13c of the tip holder 13 has been moved forward by the operation of protruding the tip 14. As a result, the annular member 15 is moved to the front side of the inner surface of the shaft cylinder 11 via the coil spring 16 and is further pressed against the front side of the inner surface, so that the first truncated conical outer surface 15b (abutment surface) A load is received from the first truncated conical inner surface 11ib (guiding surface), and the inner diameter of the annular member 15 is reduced due to the presence of the three slits 15s of the annular member 15.

The inner diameter at this diameter reduction corresponds to the outer diameter of the tip 14. That is, the minimum inner diameter (for example, about 2.35 mm to 2.45 mm) during diameter reduction allows the tip 14 (for example, φ2.5 mm) to slide smoothly in the axial direction, while allowing the tip 14 to slide smoothly in the radial direction. 14, the dimensions are such that it provides an effective steady rest. Further, even if the outer diameter of the tip 14 is smaller (for example, 2.4 mm) or larger (for example, 2.6 mm) than the above-mentioned 2.5 mm, the same annular member 15 (of the same size) can provide an equally effective steady rest. effect can be obtained. That is, the retractable writing instrument 10 of this embodiment is compatible with different types of refills having different tip outer diameters in terms of the steady rest effect. Thereby, user convenience can be improved.

In this embodiment, the limit of forward movement of the annular member 15 is defined by the second truncated conical outer surface 15d coming into contact with the second truncated conical inner surface 11id. That is, in this embodiment, the second truncated conical outer surface 15d of the annular member 15 and the second truncated conical inner surface 11id of the shaft tube 11 function as a stopper element that defines the limit of forward movement of the annular member 15. It is supposed to be done. However, such a stopper element can be omitted.

Subsequently, when the operation of protruding the tip (eg, sliding operation of the operating section provided on the side surface of the writing instrument) continues, the tip 14 (writing body) of the retractable writing instrument 10 reaches the state shown in FIG. 12.

Then, when the tip protrusion operation is completed (for example, the sliding operation of the operation section provided on the side surface of the writing instrument is released), the tip 14 (writing body) of the retractable writing instrument 10 reaches the state shown in FIG. 13. Normally, the position of the tip holder 13 is locked in the protruding state shown in FIG. 13, and the protruding state of the chip 14 is maintained until the chip is subsequently retracted. At this time, the axial length of the coil spring 16 is 9.9 mm (compressed by 10.1 mm), and the restoring force of the coil spring 16 maintains the annular member 15 in a reduced diameter state. This allows the chip 14 to be gripped without wobbling (play).

Here, even if the stopper element that defines the forward movement limit of the annular member 15 functions, the dimension of the small inner diameter cylindrical surface 15ia on the inner peripheral surface of the annular member 15 is larger than the outer diameter of the tip 14. When the diameter difference is sufficiently small (when the diameter difference is about 0.05 mm or more: see paragraph 0100), the chip holder 13 and the annular member 15 are connected to each other by a coil spring 16 so that they can move relative to each other, so that the annular member 15 It is possible to ensure that the tip 14 is effectively gripped without wobbling (play) without performing highly accurate dimensional control regarding the degree of reduction of the inner diameter of the tip.

Thereafter, when the tip is retracted (for example, re-slided on the operating section provided on the side surface of the writing instrument), the locking mechanism (not shown) is released, and the tip 14 (writing body) of the retractable writing instrument 10 is retracted. 12, and further returns to the retracted state of FIG. 9 via the state of FIG. 11 due to the action (restoring force) of the coil spring 16.

In the process from the state shown in FIG. 11 to the retracted state shown in FIG. The load that was being received from the surface) disappears. Along with this, the inner diameter of the annular member 15, which had been reduced in diameter, returns to its original state.

In addition, in the above-mentioned process of ejecting and retracting the chip, the contact surface of the annular member 15 (the first truncated conical outer surface 15b) and the guide surface of the shaft tube 11 (the first truncated conical inner surface 11ib) are in constant contact with each other. ing.

As described above, according to the retractable writing instrument 10 of the present embodiment, as the tip holder 13 moves toward the front end, the contact surface (the first truncated conical outer surface 15b) of the annular member 15 guides the barrel 11. By receiving a load from the surface (first truncated conical inner surface 11ib), the inner diameter of the annular member 15 is reduced due to the presence of the slit 15s of the annular member 15. Thereby, the shaft cylinder 11 and the annular member 15 cooperate to grip the chip 14 without wobbling (play). Furthermore, according to the retractable writing instrument 10 of the present embodiment, the stopper element that defines the forward movement limit of the annular member 15 functions, but the small inner diameter cylindrical surface 15ia of the inner peripheral surface of the annular member 15 functions. Since the dimensions are sufficiently smaller than the outer diameter of the tip 14 (the diameter difference is about 0.05 mm or more: see paragraph 0100), the tip holder 13 and the annular member 15 are connected to each other by a coil spring 16 so that they can move relative to each other. As a result, it is possible to ensure that the tip 14 is effectively gripped without wobbling (play) without performing highly accurate dimensional control regarding the degree of reduction of the inner diameter of the annular member 15, etc.

Further, according to the retractable writing instrument 10 of this embodiment, the three slits 15s as cutouts are arranged at equal intervals in the circumferential direction of the annular member 15, and each slit 15s is arranged in the axial direction of the annular member 15. Since it is elongated, the inner diameter of the annular member 15 can be reduced in a well-balanced manner in the circumferential direction.

Further, the abutment surface (first truncated conical outer surface 15b) of the annular member 15 and the guide surface (first truncated conical inner surface 11ib) of the shaft tube 11 are arranged such that the truncated conical outer surface and the truncated conical inner surface correspond to each other. Due to this, the contact surface of the annular member 15 can receive a load in a well-balanced manner in the circumferential direction, and as a result, the diameter of the annular member 15 can be reduced in a well-balanced manner in the circumferential direction. In this way, the contact surface of the annular member 15 (the first truncated conical outer surface 15b) and the guide surface of the shaft cylinder 11 (the first truncated conical inner surface 11ib) can be tapered toward the front end of each other. preferable. The tapered contact surface has a convex curved surface that is rotationally symmetrical about the axis, and the tapered guide surface has a concave curved surface that is rotationally symmetrical about the axis and has a curvature gentler than the curvature of the convex curved surface. Alternatively, it may be a concave truncated conical surface.

Further, by appropriately changing the number, size, shape, etc. of the slits 15s, the degree of elasticity (ease of diameter reduction) of the annular member 15 can be adjusted. Furthermore, by changing the material and/or wall thickness of the annular member 15, the degree of elasticity (ease of diameter reduction) of the annular member 15 can be adjusted.

Further, in this embodiment, an annular projection 11ih is provided on the inner circumferential surface of the shaft cylinder 11, and a rearward movement limit of the annular member 15 is defined. Thereby, excessive movement (particularly falling off) of the annular member 15 toward the rear side can be effectively prevented.

Further, according to the retractable writing instrument 10 of the present embodiment, the gripping portion (minimum inner diameter portion when the diameter is reduced) that grips the tip 14 in the annular member 15 is the contact surface of the annular member 15 (the first truncated conical portion). (there is no gripping portion radially inward of the contact surface). Thereby, the chip 14 can be gripped further forward, and the chip 14 can be gripped more effectively without wobbling (play).

Further, according to the retractable writing instrument 10 of this embodiment, the rear end of the slit 15s is located in front of the coil spring 16. Thereby, even when the annular member 15 is bent due to the presence of the slit 15s, a stable connection between the coil spring 16 and the annular member 15 can be maintained.

Further, according to the retractable writing instrument 10 of the present embodiment, the contact surface of the annular member 15 (the first truncated conical outer surface 15b) and the guide surface of the shaft tube 11 (the first truncated conical inner surface 11ib) are always in contact with each other. are in contact. As a result, the contact surface of the annular member 15 and the guide surface of the shaft tube 11 do not repeatedly contact and separate each time the tip 14 is operated to protrude and retract, thereby stabilizing the operation and improving the user's operational feeling. It is smooth (no discomfort).

Moreover, according to the retractable writing instrument 10 of this embodiment, the annular member 15 protrudes forward from the opening of the shaft tube 11. This allows the chip 14 to be gripped over a longer axial range, thereby ensuring that the chip 14 is gripped more effectively without wobbling (play). Furthermore, it is possible to visually appeal to the user that the retractable writing instrument 10 is equipped with a component (annular member 15) that functions as a steady rest. Furthermore, the appearance of the vicinity of the front end of the retractable writing instrument 10 with the tip 14 protruding can be smoothly connected from the rear to the nib, which can also improve the aesthetic appearance.

Further, according to the retractable writing instrument 10 of the present embodiment, the amount (length) by which the annular member 15 protrudes forward from the opening of the shaft tube 11 is smaller than the movable range of the annular member 15 in the axial direction. As a result, even when the annular member 15 is pushed into the opening of the shaft tube 11, the annular member 15 is still within the range of movement in the axial direction, so that undesired falling off of the annular member 15 is effectively prevented. can be prevented.

In addition, in the retractable writing instrument 10 of the present embodiment, a soft member (rubbing member) for a thermochromic writing instrument may be provided at the knock operation part for operating the tip 14 to eject and retract, or at the rear of the barrel 11. preferable. When the conventional configuration was adopted for a thermochromic writing instrument, there was a risk that the tip (or tip holder) would rattle due to vibrations when handwriting is rubbed, causing noise, but the configuration of this embodiment eliminates such problems. There is no risk. Therefore, it is also recommended that the configuration of this embodiment be adopted for thermochromic writing instruments.

Utility Model Hei5-85683 Utility Model Hei5-93884 JP2013-220602 JP2019-111657 PCT/JP2021/046938 (unpublished at the time of filing)

In the techniques disclosed in Patent Document 1 and Patent Document 2, the O-ring can be deformed in the radial direction, so that the effect of preventing rattling is insufficient. Furthermore, the writing part may bite into the surface of the O-ring, and the extended writing part may not be able to be smoothly stored.

On the other hand, in the technology disclosed in Patent Document 3, in order to increase the effect of preventing wobbling during writing, it is necessary to appropriately manage the dimensional relationship between the inner surface of the annular member and the outer peripheral surface of the writing part. . For example, if the gap between the outer circumferential surface of the writing section and the inner surface of the annular member is larger than the gap between the outer circumferential surface of the writing section and the inner surface of the tip of the shaft tube, wobbling during writing can be prevented. I can't get any effect. Therefore, high dimensional accuracy is required, which poses a problem in terms of productivity.

In addition, in the first type configuration and fourth type configuration of Patent Document 4, two types of coil springs are used together, so these coil springs may get caught in each other during assembly or refill replacement, impairing the smoothness of the work. There may be cases where Furthermore, when the coil springs contract as the chip holder moves in and out, there is a risk that these coil springs may become entangled, resulting in malfunction (see paragraph 0040 of Patent Document 5, etc.).

On the other hand, in the second type configuration and the third type configuration of Patent Document 4, it is difficult to increase the degree of expansion and contraction (deflection amount) of the resin spring portion, so the degree of freedom in design is low (paragraph of Patent Document 5). 0041 etc.).

According to the configuration of the first embodiment of Patent Document 5, as described above, according to the retractable writing instrument 10 of this embodiment, as the tip holder 13 moves toward the front end side, the contact surface of the annular member 15 ( When the first truncated conical outer surface 15b) receives a load from the guide surface (first truncated conical inner surface 11ib) of the shaft cylinder 11, the inner diameter of the annular member 15 is reduced due to the presence of the slit 15s of the annular member 15. Thereby, the shaft cylinder 11 and the annular member 15 cooperate to grip the chip 14 without wobbling (play).

However, in the configuration of the first embodiment of Patent Document 5, the coil spring 16 urges the annular member 15 forward even when the tip 14 (cursive writing) is in the retracted state as shown in FIG. Therefore, the contact surface of the annular member 15 receives a load from the guide surface of the shaft cylinder 11, and the inner diameter of the annular member 15 is reduced (albeit slightly). If such a state continues for a long time (if the period in which the tip 14 (cursive writing) is not protruded is long), the diameter reduction will progress to an extent exceeding the desired value due to the continuous action of the coil spring 16 ( (referred to as "creep") (if the tip 14 sometimes protrudes, it can be expected that the tip 14 will penetrate the inside of the annular member 15 and return to its original state of excessive diameter reduction). If the degree of diameter reduction exceeds a desired value, there is a possibility that the user will feel an unpleasant sense of resistance when performing the operation of protruding the tip 14 thereafter.

More specifically, with reference to FIG. 10(e), the small inner diameter cylindrical surface 15ia (φ3.0 mm, axial length 2 mm) of the annular member 15 and the first truncated conical inner surface 15ib (small diameter side φ3. When the chip 14 passes through the connection area (ridge-line boundary) between If so, there is a risk that the user may feel an unpleasant sense of resistance.

In this regard, in the configuration of the first embodiment of Patent Document 5, the second truncated conical outer surface 15d of the annular member 15 and the second truncated conical inner surface 11id of the shaft tube 11 are arranged so that the annular member 15 is directed toward the front side. It is adapted to function as a stop element that defines the limits of movement. However, the inventor of the present invention has found that the above-mentioned "creep" cannot be sufficiently suppressed because both the second truncated conical outer surface 15d and the second truncated conical inner surface 11id are tapered toward the front end. I found out that.

The present invention has been made in view of the above findings, and its purpose is to prevent the tip from wobbling when writing and provide a stable writing feeling while reducing the risk of malfunction. Furthermore, it is an object of the present invention to provide a retractable writing instrument that can maintain the smoothness of the protruding operation of the tip for a long period of time.

The present invention provides a shaft cylinder having an opening at the front end, a chip holder housed inside the shaft cylinder and movable in the axial direction of the shaft cylinder, and a chip holder fixed to the front end of the chip holder so that the chip holder can be moved. a tip that is removable from the opening of the barrel; an annular member that is loosely fitted to the inner periphery of the opening of the barrel and is movable in the axial direction of the barrel with respect to the barrel; an elastic member capable of connecting the chip holder and the annular member so as to be movable relative to each other; A contact surface that contacts a part of the inner surface of the cylinder is formed, and a notch is formed in a part of the annular member, so that when a load is applied to the contact surface, the inner diameter of the annular member changes. A guide surface is formed on a part of the inner surface of the shaft cylinder, with which the abutment surface abuts as the tip holder moves toward the front end, and the abutment The surface receives the load from the guide surface as the chip holder moves toward the front end side, and a portion of the inner surface of the shaft tube has a protuberance toward the center axis of the shaft tube. A rear surface of the raised portion has a surface perpendicular to the axial direction or a surface tapered toward the rear end, and the rear surface of the raised portion has a surface that is tapered toward the rear end. The retractable writing instrument is characterized in that a stopper part is provided on a part of the outer periphery to define the limit of forward movement of the annular member by coming into contact with the raised part.

According to the present invention, as the tip holder moves toward the front end, the contact surface of the annular member receives a load from the guide surface of the shaft cylinder, and the inner diameter of the annular member is reduced due to the presence of the notch in the annular member. diameter. Thereby, the shaft cylinder and the annular member cooperate to grip the chip or the chip holder without wobbling (play).

Further, according to the present invention, a stopper part is provided on a part of the outer periphery of the annular member, and the stopper part defines the forward movement limit of the annular member by coming into contact with the raised part on the inner surface of the shaft cylinder, and , the rear surface of the raised portion has a surface perpendicular to the axial direction or a tapered surface toward the rear end, so that the raised portion moves toward the front side of the stopper portion of the annular member. can be stopped more reliably. As a result, the above-mentioned "creep" can be sufficiently suppressed. This significantly reduces the possibility that the user will feel uncomfortable resistance when performing the operation of protruding the tip.

Preferably, the raised portion is formed in an annular shape. According to this, the occurrence of the above-mentioned "creep" can be more effectively reduced.

Further, preferably, the stopper portion is formed as an annular flange portion. According to this, the occurrence of the above-mentioned "creep" can be more effectively reduced.

Further, according to the present invention, since the elastic member can function as a "knock spring", there is no need to use a separate coil spring for the knock spring. As a result, the number of parts can be reduced, assembly work can be facilitated, and the possibility of malfunction can be significantly reduced.

Preferably, the gripping portion of the annular member that grips the tip or the tip holder is located forward of the abutment surface of the annular member (there is no gripping portion radially inward of the abutment surface). . According to this, the chip or the chip holder can be gripped further forward, and the chip or the chip holder can be gripped more effectively without wobbling (play).

Preferably, a plurality of the notches are arranged at equal intervals in the circumferential direction of the annular member, and each of the plurality of notches is a slit extending in the axial direction of the annular member. In this case, the inner diameter of the annular member can be reduced in a well-balanced manner in the circumferential direction.

Further, in this case, it is further preferable that the rear end of the slit be located in front of the elastic member. According to this, even when the annular member is bent due to the presence of the slit, a stable connection between the elastic member and the annular member can be maintained.

The abutment surface is preferably tapered toward the front end, and the guide surface is also preferably tapered toward the front end. Preferably, the abutting surface has, for example, a truncated conical surface. In this case, the guide surface is preferably a corresponding concave truncated conical surface. Alternatively, it is preferable that the abutting surface has a convex curved surface that is rotationally symmetrical around the axis. In this case, the guide surface is preferably a concave curved surface or a concave truncated conical surface that is rotationally symmetrical around the axis and has a gentler curvature than the curvature of the convex curved surface.

Further, preferably, the elastic member is a coil spring.

Further, preferably, the annular member and the elastic member are fixed to each other, the elastic member is connectable to the annular collar of the tip holder, and the elastic member is connected to the annular collar of the tip holder. It is possible to separate from In this case, since the annular member and the elastic member are held only on the barrel side, an existing replacement refill having a conventional tip holder can be used.

Preferably, the contact surface and the guide surface are always in contact with each other. In this case, since the annular member and the inner surface of the shaft cylinder do not repeatedly come into contact with and separate from each other every time the tip is moved in and out, the operation is stable and the user's operation feels smooth (no discomfort is felt).

Preferably, the annular member protrudes forward from the opening of the shaft tube. In this case, since the tip or chip holder can be gripped over a longer range, it is possible to ensure that the chip or chip holder is gripped more effectively without wobbling (play).

Further, in this case, it is further preferable that the amount (length) by which the annular member projects forward from the opening of the shaft cylinder is smaller than the movable range of the annular member in the axial direction. According to this, even when the annular member is pushed into the opening of the shaft cylinder, the annular member is still within the range of movement in the axial direction, so that it is possible to prevent the annular member from undesirably falling off. Can be done.

Preferably, a soft member is provided at the operation section for ejecting and retracting the tip or at the rear of the shaft tube. When the conventional configuration was adopted as a thermochromic writing instrument, there was a risk that the tip or tip holder would rattle due to vibrations when handwriting is rubbed, causing noise, but the configuration of the present invention does not have such a risk. . Therefore, it is recommended that the configuration of the present invention be applied to thermochromic writing instruments.

Preferably, the knock member further includes a knocking member slidably provided in the longitudinal direction with respect to the barrel, and the tip protrudes from the opening of the barrel each time the knocking member is moved forward. The annular member is moved back and forth so as to alternately repeat retraction and retraction, and the annular member is rotated with respect to the shaft cylinder each time the knock member is moved forward. According to this, since the annular member is rotated as the knocking member is moved forward (operation), the user can visually recognize the rotation of the annular member. This makes it possible to provide visual interest to the user.

Further, the present invention is directed only to the barrel of the retractable writing implement described above. That is, the present invention is capable of axially movably housing a chip holder having a chip fixed to its front end, has an opening at the front end, and allows the chip to move in and out of the opening as the chip holder moves. a barrel for a retractable writing instrument, the annular member being loosely fitted into the inner periphery of the opening of the barrel and movable in the axial direction of the barrel with respect to the barrel; an elastic member capable of connecting the chip holder and the annular member so as to be movable relative to each other; and at least a portion of the outer periphery of the annular member, the inner surface of the shaft cylinder is attached as the chip holder moves toward the front end. A notch is formed in a part of the annular member, and the inner diameter of the annular member is reduced when a load is applied on the abutment surface. A guide surface is formed on a part of the inner surface of the shaft cylinder, with which the abutment surface abuts as the tip holder moves toward the front end, and the abutment surface is As the chip holder moves toward the front end side, the load is received from the guide surface, and a raised portion is formed on a part of the inner surface of the shaft cylinder and protrudes toward the central axis of the shaft cylinder. The rear surface of the raised portion has a surface perpendicular to the axial direction or a tapered surface toward the rear end, and a portion of the outer periphery of the annular member includes: The barrel for a retractable writing instrument is characterized in that it is provided with a stopper part that defines a forward movement limit of the annular member by coming into contact with the raised part.

According to the present invention, as the tip holder moves toward the front end, the contact surface of the annular member receives a load from the guide surface of the shaft cylinder, and the inner diameter of the annular member is reduced due to the presence of the notch in the annular member. diameter. Thereby, the shaft cylinder and the annular member cooperate to grip the chip or the chip holder without wobbling (play). Further, according to the present invention, a stopper part is provided on a part of the outer periphery of the annular member, and the stopper part defines the forward movement limit of the annular member by coming into contact with the raised part on the inner surface of the shaft cylinder, and , the rear surface of the raised portion has a surface perpendicular to the axial direction or a tapered surface toward the rear end, so that the raised portion moves toward the front side of the stopper portion of the annular member. can be stopped more reliably. As a result, the above-mentioned "creep" can be sufficiently suppressed. This significantly reduces the possibility that the user will feel uncomfortable resistance when performing the operation of protruding the tip. Further, according to the present invention, since the elastic member can function as a "knock spring", there is no need to use a separate coil spring for the knock spring. As a result, the number of parts can be reduced, assembly work can be facilitated, and the possibility of malfunction can be significantly reduced.

FIG. 1 is a schematic vertical cross-sectional view of a retractable writing instrument according to an embodiment of the present invention, showing a state in which the tip (writing body) does not protrude. FIG. 2 is an enlarged vertical cross-sectional view of the tip portion of the retractable writing instrument shown in FIG. FIG. 3(a) is a perspective view of the annular member of the retractable writing implement shown in FIG. FIG. 3(b) is a plan view of the annular member of FIG. 3(a). FIG. 3(c) is a side view of the annular member of FIG. 3(a). FIG. 3(d) is a bottom view of the annular member of FIG. 3(a). FIG. 3(e) is a cross-sectional view taken along line AA in FIG. 3(c). FIG. 3(f) is a front view (view from the tip side) of the annular member of FIG. 3(a). FIG. 3(g) is a rear view of the annular member of FIG. 3(a). FIG. 2 is a schematic diagram showing a state in which the tip contacts an annular member in the process of protruding the tip in the retractable writing instrument of FIG. 1; FIG. 2 is a schematic diagram showing a state in which the tip is most protruded in the retractable writing instrument of FIG. 1 in the process of tip protrusion operation. FIG. 2 is a schematic diagram showing a state in which the tip protrudes after the tip protrusion operation is completed in the retractable writing instrument of FIG. 1; FIG. 3 is a diagram corresponding to FIG. 2 after the occurrence of "creep." FIG. 3 is a schematic vertical cross-sectional view of the retractable writing instrument according to the first embodiment of Patent Document 5, showing a state in which the tip (writing body) does not protrude. FIG. 9 is an enlarged vertical cross-sectional view of the tip portion of the retractable writing instrument shown in FIG. 8. FIG. 10(a) is a perspective view of the annular member of the retractable writing instrument shown in FIG. FIG. 10(b) is a plan view of the annular member of FIG. 10(a). FIG. 10(c) is a side view of the annular member of FIG. 10(a). FIG. 10(d) is a bottom view of the annular member of FIG. 10(a). FIG. 10(e) is a cross-sectional view taken along the line AA in FIG. 10(c). FIG. 10(f) is a front view (view from the tip side) of the annular member of FIG. 10(a). FIG. 10(g) is a rear view of the annular member of FIG. 10(a). 9 is a schematic view showing a state in which the tip contacts the annular member in the process of protruding the tip in the retractable writing instrument of FIG. 8. FIG. FIG. 9 is a schematic diagram showing a state in which the tip is most protruded in the retractable writing instrument of FIG. 8 in the process of tip protrusion operation. 9 is a schematic diagram showing a state in which the tip protrudes after the tip protrusion operation is completed in the retractable writing instrument of FIG. 8. FIG. It is a longitudinal cross-sectional view of a refill. It is a perspective view of the rear end part of a refill. It is a top view of the rear end part of a refill. FIG. 3 is a longitudinal cross-sectional view of the front shaft of an exemplary shaft cylinder. FIG. 3 is a longitudinal cross-sectional view of the intermediate shaft of an exemplary shaft cylinder. FIG. 3 is a vertical cross-sectional view of the rear shaft of an exemplary shaft cylinder. It is a longitudinal cross-sectional view of a knock member. FIG. 3 is a perspective view of the retractable rotating member. FIG. 6 is a front view of the retractable rotating member. FIG. 6 is a bottom view of the retractable rotating member. 24 is a sectional view taken along the line CC in FIG. 23. FIG. It is a schematic diagram explaining the principle of a rotary cam mechanism. It is a longitudinal cross-sectional view which shows the contact state of the refill rotating member and the rear end of a refill. It is a perspective view which shows the contact state of the refill rotating member and the rear end of a refill. FIG. 2 is a view corresponding to the enlarged view of FIG. 1, and is a view of a mode in which the winding direction of the coil spring is reversed. It is a figure corresponding to FIG.3(e), Comprising: It is a figure of the aspect in which the 1st truncated conical inner surface was replaced by the chamfer part. FIG. 30(a) is a perspective view of an annular member of a retractable writing instrument according to a modified example. FIG. 30(b) is a plan view of the annular member of FIG. 30(a). FIG. 30(c) is a side view of the annular member of FIG. 30(a). FIG. 30(d) is a bottom view of the annular member of FIG. 30(a). FIG. 30(e) is a cross-sectional view taken along line AA in FIG. 30c). FIG. 30(f) is a front view (view from the tip side) of the annular member of FIG. 30(a). FIG. 30(g) is a rear view of the annular member of FIG. 30(a).

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic vertical cross-sectional view of a retractable writing instrument 110 according to an embodiment of the present invention, showing a state in which a tip 114 (writing body) does not protrude. FIG. 2 is an enlarged vertical cross-sectional view of the tip portion of the retractable writing instrument 110 of this embodiment.

3(a) is a perspective view of the annular member 115 of the retractable writing instrument 110 of this embodiment, and FIG. 3(b) is a plan view of the annular member 115 of FIG. 3(a). 3(c) is a side view of the annular member 115 of FIG. 3(a), FIG. 3(d) is a bottom view of the annular member of FIG. 3(a), and FIG. 3(e) is a side view of the annular member 115 of FIG. 3(a). 3(c) is a cross-sectional view taken along the line AA, FIG. 3(f) is a front view (view from the tip side) of the annular member of FIG. 3(a), and FIG. 3(g) is It is a back view of the annular member of Fig.3 (a).

Furthermore, FIG. 4 is a schematic diagram showing a state in which the tip 114 is in contact with the annular member 115 in the process of protruding the tip 114 in the retractable writing instrument 110 of this embodiment, and FIG. In the retractable writing instrument 110, it is a schematic diagram showing a state in which the tip 114 is most protruded in the process of the protruding operation of the tip 114, and FIG. FIG. 4 is a schematic diagram showing a state in which the chip 114 protrudes after the above-mentioned operation.

A retractable writing instrument 110 according to one embodiment shown in FIGS. 1 to 6 includes a cylindrical barrel 111 having an opening at the front end. As shown in FIG. 1, the shaft tube 111 has a rear portion 111r and a front portion 111m in this embodiment. The rear part 111r and the front part 111m are removably fixed by screw connection (threaded engagement). However, the rear part 111r and the front part 111m may be fixed by fitting or may be formed integrally.

A chip holder 113 that is movable in the axial direction of the shaft cylinder 111 is housed inside the shaft cylinder 111 . A tip 114, which is a cursive script, is fixed to the front end of the tip holder 113. As the chip holder 113 moves, the chip 114 can move in and out of the opening of the shaft tube 111, as shown in FIGS. 4 to 6.

As shown in FIG. 2, the tip holder 113 has a base end portion 113a, a first collar portion 113b, and a second collar portion 113c in this order from the base end side to the distal end side. The base end portion 113a and the first collar portion 113b are both cylindrical portions in this embodiment, and the second collar portion 113c is a truncated conical portion in this embodiment, and their cross-sectional diameters are The mutual relationship is base end portion 113a>first collar portion 113b>second collar portion 113c.

In this embodiment, as shown in FIG. 2, an annular member 115 that is movable in the axial direction of the shaft tube 111 is loosely fitted to the inner periphery of the opening of the shaft tube 111. The front end of the annular member 115 is located further forward than the front end of the shaft tube 111. The rear side of the annular member 115 has an enlarged outer diameter and inner diameter, and covers the periphery of the tip 114 (which has a diameter of 2.5 mm) in a non-contact manner.

Further, the annular member 115 is fixed to the front end of a coil spring 116 (an example of an elastic member). The coil spring 116 surrounds the second collar portion 113c of the chip holder 113 and the chip 114 in a loosely fitted state (with a gap), and the rear end of the coil spring 116 is constantly pressed by the base end 113a of the chip holder 113. Yes (not fixed). Thereby, the coil spring 116 connects the chip holder 113 and the annular member 115 so that they can move relative to each other. As shown in FIGS. 4 to 6, as the tip holder 113 moves and the coil spring 116 expands and contracts, the annular member 115 becomes movable relative to the shaft tube 111 in the axial direction of the shaft tube 111. ing.

The annular member 115 is made of resin (for example, polyacetal, polypropylene, polyethylene) or metal (for example, brass).

Further, as shown in FIGS. 3(a) to 3(g), the outer circumferential surface of the annular member 115 has a small outer diameter cylindrical surface 115a (φ3.6 mm, axial length 1.6 mm) from the front side. , a first truncated conical outer surface 115b (axial length 1.1 mm) as a tapered contact surface, a middle outer diameter cylindrical surface 115c (φ4.85 mm, axial length 1.5 mm), and a tapered A second truncated conical outer surface 115d (axial length 1.6 mm) as a contact surface, a first large outer diameter cylindrical surface 115e (φ6.1 mm, axial length 1.2 mm, and an annular shape as a stopper portion) A stepped surface (flange portion) 115f (a surface perpendicular to the axial direction) and a second large outer diameter cylindrical surface 115g (φ6.6 mm, axial length 3.3 mm) are provided in this order. Note that the annular stepped surface (flange portion) 115f serving as the stopper portion may be a surface substantially perpendicular to the axial direction (approximately 85° to 95°).

Further, as shown in FIG. 3E, the inner circumferential surface of the annular member 115 includes, from the front side, a small inner diameter cylindrical surface 115ia (φ3.0 mm, axial length 2 mm), a first truncated conical inner surface 115ib, and a first truncated conical inner surface 115ib. (axial length 0.5 mm), medium inner diameter cylindrical surface 115ic (φ3.6 mm, axial length 3.9 mm), second truncated conical inner surface 115id (axial length 0.4 mm), and four surfaces. The sweeping part 115ie (inscribed circle φ5.28 mm, axial length 0.9 mm), the large inner diameter cylindrical surface 115if (φ5.43 mm, axial length 2.1 mm), and the third truncated conical inner surface 115ig (axis direction length 0.4 mm) are provided in this order. As shown in FIG. 2, in this embodiment, the front end of the coil spring 116 is fixed (fitted and fixed) on the four-sided sweeping part 115ie.

Furthermore, the annular member 115 of this embodiment is provided with three slits 115s as cutouts. As shown in FIGS. 3A to 3G, the three slits 115s are arranged at equal intervals (every 120 degrees) in the circumferential direction of the annular member 115. Each of the three slits 115s has a width of 0.8 mm and extends in the axial direction of the annular member 115 from the front end to approximately the center of the second truncated conical outer surface 115d (maximum axial length 5.5 mm). ).

As a result, when a load is applied to the first frustoconical outer surface 115b (abutting surface), the inner diameter of the annular member 115 is flexibly reduced, and when the load is released, the annular member The inner diameter of 115 is designed to return elastically.

On the other hand, as shown in FIG. 2, FIG. 5, or FIG. 6, the inner circumferential surface near the opening of the shaft tube 111 has a small inner diameter cylindrical surface 111ia (φ3.7 mm, axial length 1.2 mm) from the front side. , a first truncated conical inner surface 111ib (axial length 1.1 mm) as a tapered guide surface, a medium inner diameter cylindrical surface 111ic (φ4.95 mm, axial length 1.3 mm), and a tapered guide surface. The second truncated conical inner surface 111id (axial length 1.4 mm) as a surface, the first large inner diameter cylindrical surface 111ie (φ6.3 mm, axial length 1.4 mm), and the central axis of the shaft cylinder 111. A circular ring surface 111if (a surface perpendicular to the axial direction) corresponding to the rear side surface of the protrusion 111p that protrudes toward the rear, and a second large inner diameter cylindrical surface 111ig (φ6.7 mm, axial length 4.2 mm) ) and an annular projection 111ih (minimum aperture diameter φ6.5 mm) as a regulating element are provided in this order. Note that the circular ring surface 111if corresponding to the rear side surface of the protrusion 111p that protrudes toward the central axis of the shaft tube 111 is a surface substantially perpendicular to the axial direction (approximately 85° to 95°). good.

As a result, the first truncated cone outer surface 1115b (contact surface) receives a load from the first truncated cone inner surface 11ib (guide surface) as the tip holder 13 moves toward the front end. ing.

Note that the coil spring 116 of this embodiment allows the tip 114 to be retracted when the tip 114 is retracted (for example, a sliding operation of the operating section provided on the side of the writing instrument for releasing the locking mechanism that maintains the protruding state of the tip 114). It also has a function of automatically retracting the holder 113. That is, the coil spring 116 functions as a so-called knock spring. (The operating load is about 50 gf to 300 gf (about 0.49 N to 2.94 N). For example, the operating load when not in use (Figure 2) is 68 gf, the load at full stroke (Figure 5) is 288 gf, The operating load from the time (Fig. 6) is 227 gf. Also, the spring constant is 0.23 N/mm).

The retractable writing instrument 110 configured as described above operates as follows.

When not in use, the tip 114 (cursive) of the retractable writing instrument 110 is in a retracted state as shown in FIGS. 1 and 2. Immediately after manufacturing, the axial length of the coil spring 116 is 17 mm (the length has been compressed by about 2 mm in advance), the annular member 115 has not been reduced in diameter, and the small inner diameter cylindrical surface 115ia of the annular member 115 is The diameter remains φ3.0 (>the outer diameter of the tip 114).

On the other hand, if the above-mentioned "creep" has occurred due to a long period of time being left unused after manufacturing, the axial length of the coil spring 116 is longer than 17 mm and the annular member 115 has already been removed. The diameter is reduced, and the small inner diameter cylindrical surface 115ia of the annular member 115 is smaller than φ3.0.

Here, in the retractable writing instrument 110 of the present embodiment, a part of the outer periphery of the annular member 115 comes into contact with the raised portion 111p on the inner surface of the shaft tube 111, thereby defining the forward movement limit of the annular member 115. The flange surface 115f is provided as a stopper portion to prevent the raised portion 111p from moving, and the circular ring surface 111if, which is the rear side surface of the raised portion 111p, is a surface perpendicular to the axial direction. Movement of the annular member 115 (the flange surface 115f thereof) toward the front side can be more reliably stopped. As a result, regarding the degree of the above-mentioned "creep", the state in which the flange surface 115f and the circular ring surface 111if are in contact can be set as the maximum allowable limit (see FIG. 7). This significantly reduces the possibility that the user will feel uncomfortable resistance when performing the operation of protruding the tip. (In the embodiment described in Patent Document 5, the progress of the above-mentioned "creep" is not stopped, so the "creep" progresses to the extent that the user feels an unpleasant feeling of resistance when the tip is ejected.) There was a risk that it would happen.)

According to the knowledge obtained by the inventor of the present invention, in the case of each specification of the shaft tube 111, annular member 115, and coil spring 116 adopted in this embodiment, from the position occupied by the coil spring 116 immediately after manufacture (see FIG. 2), It is preferable that the position of the coil spring 116 in a state where the flange surface 115f and the circular ring surface 111if are in contact (see FIG. 7) is designed within a range of approximately 0.2 mm to 1.0 mm.

Now, when the tip is protruded (for example, the sliding operation of the operating section provided on the side surface of the writing instrument) is performed, the tip 114 (writing body) of the retractable writing instrument 110 reaches the state shown in FIG. 4.

In the state shown in FIG. 4, the second collar portion 113c of the tip holder 113 is moved forward by the operation of protruding the tip 114. As a result, the annular member 115 is moved to the front side of the inner surface of the shaft tube 111 via the coil spring 116 and is further pressed against the front side of the inner surface, so that the first truncated conical outer surface 115b (abutting surface) A load is received from the first truncated conical inner surface 111ib (guiding surface), and the inner diameter of the annular member 115 is reduced due to the presence of the three slits 15s of the annular member 115 (due to the above-mentioned "creep", the tip 114 If the diameter has already been reduced before the protruding operation of the tip 114, the degree of diameter reduction is further increased by the protruding operation of the tip 114).

The inner diameter during this diameter reduction (in the state shown in FIG. 4) is designed to correspond to the outer diameter of the tip 114. That is, the minimum inner diameter (for example, about 2.35 mm to 2.45 mm) during diameter reduction allows the tip 114 (for example, φ2.5 mm) to slide smoothly in the axial direction, while allowing the tip 114 (for example, φ2.5 mm) to slide smoothly in the radial direction. 114, the dimensions are such that it provides an effective steady rest. Furthermore, even if the outer diameter of the tip 114 is smaller (e.g., 2.4 mm) or larger (e.g., 2.6 mm) than the aforementioned 2.5 mm, the same annular member 115 (of the same size) can provide an equally effective steady rest. effect can be obtained. That is, the retractable writing instrument 110 of the present embodiment is compatible with different types of refills having different tip outer diameters in terms of the steady rest effect. Thereby, user convenience can be improved.

Subsequently, when the tip protrusion operation (for example, sliding operation of the operating section provided on the side surface of the writing instrument) continues, the tip 114 (writing body) of the retractable writing instrument 110 reaches the state shown in FIG. 5.

Then, when the tip protrusion operation is completed (for example, the sliding operation of the operation section provided on the side surface of the writing instrument is released), the tip 114 (writing body) of the retractable writing instrument 110 reaches the state shown in FIG. 6. Normally, the position of the tip holder 113 is locked in the protruding state shown in FIG. 6, and the protruding state of the chip 114 is maintained until the chip is subsequently retracted. At this time, the axial length of the coil spring 116 is 9.9 mm (compressed by 10.1 mm from the state shown in FIG. 2), and the restoring force of the coil spring 116 maintains the annular member 115 in the reduced diameter state. This allows the chip 114 to be gripped without wobbling (play).

Here, if the dimension of the small inner diameter cylindrical surface 115ia of the inner peripheral surface of the annular member 115 is sufficiently smaller than the outer diameter of the tip 114 (if the diameter difference is about 0.05 mm or more: see paragraph 0100), the tip Since the holder 113 and the annular member 115 are connected to each other so as to be movable relative to each other by the coil spring 116, the chip 114 can be prevented from wobbling without performing highly accurate dimensional control regarding the degree of reduction of the inner diameter of the annular member 115. It is possible to guarantee effective gripping without any play.

Thereafter, when the tip is retracted (for example, re-slided on the operating section provided on the side of the writing instrument), the locking mechanism (not shown) is released, and the tip 114 (writing body) of the retractable writing instrument 110 is retracted. 5, and further returns to the retracted state of FIG. 2 via the state of FIG. 4 due to the action (restoring force) of the coil spring 116.

In the process from the state shown in FIG. 4 to the retracted state shown in FIG. The load that was being received from the surface) disappears. Along with this, the inner diameter of the annular member 115, which had been reduced in diameter, returns to its original state (returns to an unreduced state or to a reduced diameter state due to creep).

In addition, in the above-mentioned process of ejecting and retracting the chip, the contact surface of the annular member 115 (the first truncated conical outer surface 115b) and the guide surface of the shaft tube 111 (the first truncated conical inner surface 111ib) are constantly in contact with each other. ing.

As described above, according to the retractable writing instrument 110 of the present embodiment, as the tip holder 113 moves toward the front end side, the contact surface (the first truncated conical outer surface 115b) of the annular member 115 guides the shaft tube 111. By receiving a load from the surface (first truncated conical inner surface 111ib), the inner diameter of the annular member 115 is reduced due to the presence of the slit 115s of the annular member 115. Thereby, the shaft cylinder 111 and the annular member 115 cooperate to grip the chip 114 without wobbling (play).

Further, according to the retractable writing instrument 110 of the present embodiment, the forward movement limit of the annular member 115 is defined by a part of the outer periphery of the annular member 115 coming into contact with the raised portion 111p on the inner surface of the shaft tube 111. A flange surface 115f is provided as a stopper portion, and a circular ring surface 111if, which is a rear side surface of the raised portion 111p, is a surface perpendicular to the axial direction. As a result, the raised portion 111p can more reliably stop the forward movement of the annular member 115 (the flange surface 115f thereof), and as a result, regarding the degree of the above-mentioned "creep", the flange surface 115f and the circular ring surface 111if can be set as the maximum allowable limit (see FIG. 7). This significantly reduces the possibility that the user will feel uncomfortable resistance when performing the operation of protruding the tip.

In particular, according to the retractable writing instrument 110 of this embodiment, since the protrusion 111p of the barrel 111 (the circular ring surface 111if, which is the rear surface thereof) is formed in an annular shape, the above-mentioned "creep" occurs. can be reduced more effectively. However, at least at the time of filing this application, an embodiment in which raised portions are provided discretely in the circumferential direction is also included within the scope of the present invention.

Further, according to the retractable writing instrument 110 of the present embodiment, the flange surface 115f serving as the stopper portion of the annular member 115 is formed in an annular shape, so that the occurrence of the above-mentioned "creep" can be more effectively reduced. be able to. However, at least at the time of filing this application, an embodiment in which stopper portions are provided discretely in the circumferential direction is also included within the scope of the present invention.

Furthermore, according to the retractable writing instrument 110 of the present embodiment, the dimension of the small inner diameter cylindrical surface 115ia of the inner peripheral surface of the annular member 115 is sufficiently smaller than the outer diameter of the tip 114 (the diameter difference is about 0.05 mm or more). Since the tip holder 113 and the annular member 115 are connected to each other so as to be movable relative to each other by the coil spring 116, the degree of reduction of the inner diameter of the annular member 115 can be controlled with high precision. Even without such an arrangement, it is possible to ensure that the chip 114 is effectively gripped without wobbling (play).

Further, according to the retractable writing instrument 110 of this embodiment, the three slits 115s as cutouts are arranged at equal intervals in the circumferential direction of the annular member 115, and each slit 115s is arranged in the axial direction of the annular member 115. Since it is elongated, the inner diameter of the annular member 115 can be reduced in a well-balanced manner in the circumferential direction.

Further, the abutment surface (first truncated conical outer surface 115b) of the annular member 115 and the guide surface (first truncated conical inner surface 111ib) of the shaft tube 111 are arranged such that the truncated conical outer surface and the truncated conical inner surface correspond to each other. Due to this, the contact surface of the annular member 115 can receive a load in a well-balanced manner in the circumferential direction, and as a result, the diameter of the annular member 115 can be reduced in a well-balanced manner in the circumferential direction. In this way, the contact surface of the annular member 115 (the first truncated conical outer surface 115b) and the guide surface of the shaft tube 111 (the first truncated conical inner surface 111ib) can be tapered toward the front end of each other. preferable. The tapered contact surface has a convex curved surface that is rotationally symmetrical about the axis, and the tapered guide surface has a concave curved surface that is rotationally symmetrical about the axis and has a curvature gentler than the curvature of the convex curved surface. Alternatively, it may be a concave truncated conical surface.

Further, by appropriately changing the number, size, shape, etc. of the slits 115s, the degree of elasticity (ease of diameter reduction) of the annular member 115 can be adjusted. Furthermore, by changing the material and/or wall thickness of the annular member 115, the degree of elasticity (ease of diameter reduction) of the annular member 115 can be adjusted.

Further, in this embodiment, an annular projection 111ih is provided on the inner circumferential surface of the shaft cylinder 111, and a rearward movement limit of the annular member 115 is defined. Thereby, excessive movement (particularly falling off) of the annular member 115 toward the rear side can be effectively prevented.

Further, according to the retractable writing instrument 110 of the present embodiment, the gripping portion (minimum inner diameter portion when the diameter is reduced) that grips the tip 114 in the annular member 115 is the contact surface of the annular member 115 (the first truncated conical portion). outer surface 115b) (there is no gripping portion radially inward of the contact surface). Thereby, the chip 114 can be gripped further forward, and the chip 114 can be gripped more effectively without wobbling (play).

Further, according to the retractable writing instrument 110 of this embodiment, the rear end of the slit 115s is located in front of the coil spring 116. Thereby, even when the annular member 115 is bent due to the presence of the slit 115s, a stable connection between the coil spring 116 and the annular member 115 can be maintained.

Further, according to the retractable writing instrument 110 of the present embodiment, the contact surface of the annular member 115 (the first truncated conical outer surface 115b) and the guide surface of the shaft tube 111 (the first truncated conical inner surface 111ib) are always in contact with each other. are in contact. As a result, the contact surface of the annular member 115 and the guide surface of the shaft tube 111 do not repeatedly contact and separate each time the tip 114 is moved in and out, so the operation is stable and the user's operation feeling is improved. It is smooth (no discomfort).

Further, according to the retractable writing instrument 110 of this embodiment, the annular member 115 protrudes forward from the opening of the shaft tube 111. This allows the chip 114 to be gripped over a longer axial range, thereby ensuring that the chip 114 is gripped more effectively without wobbling (play). Furthermore, it is possible to visually appeal to the user that the retractable writing instrument 110 is equipped with a component (the annular member 115) that acts as a steady rest. Furthermore, the appearance of the vicinity of the front end of the retractable writing instrument 110 with the tip 114 protruding can be smoothly connected from the rear to the nib, which can improve the appearance.

Further, according to the retractable writing instrument 1110 of this embodiment, the amount (length) by which the annular member 115 protrudes forward from the opening of the shaft tube 111 is smaller than the movable range of the annular member 115 in the axial direction. As a result, even when the annular member 115 is pushed into the opening of the shaft tube 111, the annular member 115 is still within the range of movement in the axial direction, so that undesired falling off of the annular member 115 is effectively prevented. can be prevented.

In addition, in the retractable writing instrument 110 of this embodiment, a soft member (rubbing member) for a thermochromic writing instrument may be provided at the knock operation portion for operating the tip 114 to extend or retract, or at the rear of the barrel 111. preferable. When the conventional configuration was adopted for a thermochromic writing instrument, there was a risk that the tip (or tip holder) would rattle due to vibrations when handwriting is rubbed, causing noise, but the configuration of this embodiment eliminates such problems. There is no risk. Therefore, it is also recommended that the configuration of this embodiment be adopted for thermochromic writing instruments.

(Modified example)
The rear surface of the raised portion 111p on the inner surface of the shaft tube 111 may have a tapered surface toward the rear end. For example, the rear surface of the raised portion 111p on the inner surface of the shaft tube 111 may be a truncated conical surface that tapers toward the rear end. The shaft tube 111 itself may be processed in this way, or a separate annular spacer member having a flat annular shape on the front end side and a truncated conical surface shape on the rear end side may be placed on the circular ring surface of the shaft tube 111. It may be fixed by adhesive or the like.

In such a case, the stopper portion of the annular member 115 that is the abutting partner may also be formed into a concave truncated conical surface corresponding to the truncated conical surface on the rear side of the raised portion 111p. The annular member 115 itself may be processed in this manner, or a separate annular spacer member having a flat annular shape on the rear end side and such a concave truncated conical shape on the front end side may be provided on the flange surface of the annular member 115. It may be fixed by adhesive or the like.

(Supplementary information about refills)
The retractable writing instruments 110 and 210 of each of the embodiments described above have a barrel 111, a refill (writing body) housed in the barrel 111, and a tip 114 of the refill that can be freely retracted and retracted from the opening of the barrel 111. This is a writing instrument equipped with a retractable mechanism.

An example of the refill will be supplementarily explained using FIGS. 14 to 16. Referring to FIG. 14, the refill 6 includes, for example, a pen tip (tip) 61, an ink storage tube 62 in which the pen tip 61 is press-fitted into the front end opening, and an ink storage tube 62 filled with the ink storage tube 62. A thermochromic ink, a follower (for example, a high viscosity fluid) that is filled adjacent to the rear end side of the thermochromic ink and moves forward as the thermochromic ink is consumed, and the rear end of the ink storage tube 62. It consists of a tail plug 63 attached to the opening. The tail plug 63 is provided with an air hole 63a that opens toward the rear end. The air hole 63a allows ventilation between the inside and outside of the ink storage tube 62.

The pen nib 61 may, for example, be composed of only a metal ballpoint pen tip that rotatably holds a ball at the front end, or a synthetic resin pen nib that holds such a ballpoint pen tip and the rear outer surface of the ballpoint pen tip. A configuration consisting of a combination with a holder. A spring that presses the ball at the front end forward is housed inside the pen tip 61. The spring has, for example, a compression coil spring with a rod section at its front end, and the front end of the rod section is in contact with the rear surface of the ball. When not writing, the ball is brought into close contact with the inner surface of the inwardly directed front edge of the front end of the ballpoint pen tip due to the forward bias of the spring. This prevents ink from leaking from the front end of the pen tip 61 and from evaporating.

(Supplementary information regarding the rear end of the shaft tube 111)
The shaft cylinder 111 of this embodiment includes, for example, a tapered cylindrical front shaft 3 (see FIG. 17), a cylindrical intermediate shaft 4 connected to the rear end of the front shaft 3 (see FIG. 18), It consists of a cylindrical rear shaft 5 (see FIG. 19) connected to the rear end of the intermediate shaft 4.

For example, as shown in FIG. 19, a mounting hole 52 may be provided through the rear end of the rear shaft 5 in the front-rear direction, and a friction portion 53 made of an elastic material may be press-fitted into the mounting hole 52. . Thereby, the friction portion 53 can be fixed to the outer surface of the rear end portion of the rear shaft 5. Furthermore, an inward protrusion 54 may be integrally formed on the inner surface of the rear shaft 5.

The elastic material constituting the friction part 53 is preferably, for example, a synthetic resin (rubber, elastomer) having elasticity, such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene- butylene-styrene copolymer), fluororesin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM), or a mixture of two or more rubber elastic materials, and combinations of rubber elastic materials and synthetic resins. Examples include mixtures.

The synthetic resin having elasticity constituting the friction part 53 may be made of a low-abrasive elastic material that hardly generates abrasion scum (erasing scum) during friction, rather than a high-abrasive elastic material (for example, an eraser, etc.). preferable. Further, the friction portion 53 may be provided on the outer surface of the rear end portion of the shaft tube 111 in various ways. For example, a mode in which the friction part 53 made of an elastic material is provided on the outer surface of the rear end of the shaft cylinder 111 or the rear end of the rear shaft 5 by press-fitting, engaging, screwing, fitting, adhesion, two-color molding, etc. Alternatively, the entire shaft cylinder 111 or the entire rear shaft 5 may be integrally formed of an elastic material.

(Supplementary information regarding knock member 8)
Referring to FIG. 20, a clip 83 extending in the front-rear direction can be fixed to the knock member 8. A ball portion may be provided protruding from the back surface of the clip 83. The knocking member 8 includes, for example, a base 81 to which the rear end of the clip 83 is fixed, and a cylindrical shaft 82 that is integrally connected to the base 81 and extends forward from the base 81.

The knock member 8 is obtained by, for example, a molded body of synthetic resin (for example, polycarbonate resin). The clip 83 is made of, for example, a molded body of synthetic resin (for example, polycarbonate resin) or a metal material (for example, stainless steel). The knock member 8 and the clip 83 may be integrally formed of synthetic resin.

As shown in FIG. 20, cam teeth 82a that engage with the rear end of the protrusion 71 of the retractable rotation member 7 (see FIGS. 21 to 24) may be integrally formed at the front end of the shaft portion 82.

To assemble the knocking member 8, insert the base 81 of the knocking member 8 into the first long hole 41 of the intermediate shaft 4 from the rear end (opening part) of the first long hole 41, and The shaft portion 82 of the knocking member 8 is inserted into the intermediate shaft 4. Thereafter, the inner surface of the rear shaft 5 is attached to the intermediate shaft 4 so that the first elongated hole 41 of the intermediate shaft 4 and the second elongated hole 51 of the rear shaft 5 communicate with each other in the radial direction (so that they overlap in the radial direction). The base 81 of the knocking member 8 is inserted into the second elongated hole 51 of the rear shaft 5 from the front end (opening portion) thereof while fitting the knock member 8 into the outer surface of the reduced diameter portion. . As a result, the intermediate shaft 4 and the rear shaft 5 are connected (the outward projection 44 of the intermediate shaft 4 and the inward projection 54 of the rear shaft 5 are crossed over and engaged with each other), and the first elongated hole 41 and the second elongated hole 41 are connected to each other. A slide hole 21 extending in the front-rear direction is formed by the elongated hole 51, and the knock member 8 is projected radially outward from the slide hole 21. The knock member 8 is slidable in the front-rear direction (slidable in the front-rear direction) along the slide hole 21.

By connecting the rear shaft 5 to the rear end of which the friction part 53 is fixed to the rear end of the intermediate shaft 4, the friction part 53 is always fixed to the rear end of the shaft cylinder 111. Further, since the front shaft 3 and the intermediate shaft 4 are removably connected by screwing, the refill 6 can be replaced at any time.

(Supplementary information about the appearance mechanism)
The ejection and retraction mechanism of this embodiment is a side slide type ejection and retraction mechanism using a rotary cam mechanism, and each time the knock member 8 and the knock member 8 are moved forward, the pen tip 61 is moved from the opening of the shaft tube 111. A protruding/retracting rotating member 7 that moves back and forth to protrude or retract and also rotates the refill 6 (therefore, the pen tip 61), and a protruding/retracting rotating member 7 that is provided in the barrel 111 and engages or engages with the protruding/retracting rotating member 7 depending on the position of the knock member 8. It consists of the above-mentioned cam portion 43 that can be disengaged and a knock spring 12 (for example, a compression coil spring) that is provided inside the barrel 111 and biases the refill 6 rearward.

The projecting/retracting mechanism of this embodiment is of a double knock type in which both the pen tip protruding operation and the pen tip retracting operation press the knock member 8 forward (slide forward).

(Supplementary information regarding thermochromic ink)
In this embodiment, the thermochromic ink is preferably a reversible thermochromic ink. Reversible thermochromic ink is a heat-erasable type that erases the color by heating from a colored state, a color memory retention type that tautonically stores and maintains the colored or erased state within a specific temperature range, or a color-retaining type that erases the color by heating from a colored state. Various types can be used alone or in combination, such as a heated coloring type that develops color by heating and returns to a decolorized state by cooling from the colored state.

Examples of the coloring material contained in the reversible thermochromic ink include (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction in which the two are chemically linked ( A reversible thermochromic pigment in which a reversible thermochromic composition containing at least three essential components of a reaction medium that determines the temperature at which the color reaction occurs is encapsulated in microcapsules is preferably used.

(Supplementary note regarding rotation of refill 6)
As described above, in this embodiment, each time the knocking member 8 is moved forward, it moves back and forth so that the pen tip 61 protrudes or retracts from the opening of the barrel 111, and the refill 6 (therefore, the pen tip 61 ) is rotated. Writing instruments in which the pen tip 61 rotates in this manner are popular in the market because the wear of the pen tip 61 can be equalized.

FIG. 25 is a schematic diagram illustrating the principle of the rotating cam mechanism. Referring to FIG. 25, when the knocking member 8 is pushed forward (slided) from the pen tip retracted state (see FIG. 25(a)) against the backward bias by the projectile (not shown). , the protrusion 71 of the retractable rotary member 7, which was engaged with the cam tooth 82a, is pushed forward via the cam tooth 82a on the front end of the shaft portion 82 of the knocking member 8. The protrusion 71 of the retractable rotating member 7 is moved forward along the cam groove 43b.

When the protrusion 71 of the protruding and retractable rotating member 7 is moved forward, the protruding and retractable rotating member 7 presses the refill 6 forward through the abutting relationship between the contact portion 73 and the protruding piece 63b of the tail plug 63. do. Then, the pen tip 61 is made to protrude outside from the opening of the shaft tube 111.

At the deepest position of the knocking operation of the knocking member 8, the rear end of the protrusion 71 moves out of the cam groove 43b of the cam portion 43 and falls into the valley of the cam teeth 82a of the knocking member 8. The retractable rotating member 7 rotates slightly in the circumferential direction (see FIG. 25(b)).

Subsequently, when the knocking member 8 returns to its original position due to the backward bias from the elastic body, the rear end of the protrusion 71 moves so as to fall into the valley of the cam teeth 43a of the cam portion 43, and accordingly. The retractable rotating member 7 further rotates in the circumferential direction (see FIG. 25(c)). Further, since the rear end of the protrusion 71 remains at the trough of the cam tooth 43a of the cam portion 43, the pen tip protrudes state is maintained.

Next, when the knock member 8 is pressed forward (slide operation) from the pen tip protruding state (see FIG. 25c), the cam tooth 82a at the front end of the shaft portion 82 of the knock member 8 causes the retractable rotating member 7 to move again. The rear end of the protrusion 71 is engaged and pressed forward.

At the deepest position of the knocking operation of the knocking member 8, the rear end of the protrusion 71 moves over the peaks (teeth) of the cam teeth 43a of the cam part 43 and falls into the valleys of the cam teeth 82a of the knocking member 8. However, along with this, the retractable rotating member 7 slightly rotates in the circumferential direction (see FIG. 25(d)). Further, when the knocking member 8 returns to its original position due to the backward bias from the projectile, the projection 71 is introduced into the cam groove 43b, and the pen tip retracted state is maintained (Fig. 25(a) )reference).

26 and 27 show a state in which the protruding piece 63b of the tail plug 63 and the abutting portion 73 of the retractable rotating member 7 are in contact with each other.

The contact portion 73 on the front surface of the retractable rotating member 7 is brought into contact with the projection 63b of the tail plug 63 at the rear end of the refill 6, and the plurality of protrusions 72 on the front surface of the retractable rotary member 7 It is inserted into the gap 63c between the projecting pieces 63b of the tail plug 63 at the rear end and engaged in the circumferential direction. As a result, as the retractable rotating member 7 rotates in the circumferential direction, the refill 6 is also rotated in the circumferential direction.

As described above, in this embodiment, the contact portion 73 on the front surface of the retractable rotating member 7 rotates the tail plug 63 at the rear end of the refill 6. However, a mode in which the retractable rotating member 7 transmits rotational force to other parts of the refill 6 may also be adopted. For example, an embodiment may be adopted in which the tail plug 63 is not provided and a plurality of protrusions are integrally formed at the rear end of the refill 6.

(Supplementary information regarding the rotation of the annular member 115)
When the refill 6 is rotated with respect to the barrel 111 by the pressing operation of the knock member 8, the annular member 115 connected to the refill 6 via the coil spring 116 is also rotated with respect to the barrel 111.

At this time, the front end of the coil spring 116 is fixed to the annular member 115. As a result, the front end of the coil spring 116 does not slide on the inner surface of the annular member 115, so there is no risk of the front end damaging the annular member 115. Further, the annular member 115 connected to the refill 6 via the coil spring 116 is also rotated with respect to the shaft tube 111, so that the refill 6 and the coil spring 116 can rotate together. As a result, the rear end of the coil spring 116 does not slide on the chip holder 113, so there is no risk of the rear end damaging the chip holder 113. Further, since the refill 6, the annular member 115, and the coil spring 116 rotate together, there is no possibility that the smooth rotation of the refill 6 (and thus the pressing operation of the knocking member 8) will be hindered. Furthermore, since the rotation of the annular member 115 is visible, it is possible to provide visual interest to the user.

(Rotation direction of refill 6 and winding direction of coil spring 116)
In the embodiment described above, the rotation direction of the refill 6 is clockwise when viewed from the rear end side, and the winding direction of the coil spring 116 is counterclockwise (so-called left-handed spring) (reversing from the start of winding. (extending clockwise: see Figure 2).

However, if the rotational direction of the refill 6 and the winding direction of the coil spring 116 are aligned, the tip holder 113 (the coil spring contact portion thereof) will be oriented so as to push the rear end of the coil spring 116 when the refill 6 rotates. Therefore, the connection between the tip holder 113 and the coil spring 116 becomes firm (for example, in such a manner that they are hooked together), and the coil spring 116 preferably transmits the rotational force of the refill 6 to the annular member 115. .

FIG. 28 is a diagram corresponding to FIG. 2, in which the winding direction of the coil spring 116 is reversed.

Here, it is further preferable that the coil spring abutting portion of the chip holder 113 be provided with an uneven shape or the like to make the connection with the rear end of the coil spring 116 more solid.

(R chamfering of the inner peripheral surface of the annular member 115)
As described with reference to FIG. 3(e), the inner circumferential surface of the annular member 115 includes, from the front side, a small inner diameter cylindrical surface 115ia, a first truncated conical inner surface 115ib, a medium inner diameter cylindrical surface 115ic, and a third inner diameter cylindrical surface 115ic. Two truncated conical inner surfaces 115id, a four-sided flattened portion 115ie, a large inner diameter cylindrical surface 115if, and a third truncated conical inner surface 115ig are provided in this order. Here, an R chamfer may be provided in the connection region (boundary) between the small inner diameter cylindrical surface 115ia and the first truncated conical inner surface 115ib. In this case, when the tip 114 is inserted into the small inner diameter cylindrical surface 115ia, smoother insertion can be realized because there is no catch.

Furthermore, as shown in FIG. 29, instead of providing the first truncated conical inner surface 115ib as shown in FIG. (The first truncated conical inner surface 115ib is replaced by a chamfered portion 15ib') may be adopted. Also in this case, when the tip 114 is inserted into the small inner diameter cylindrical surface 15ia', smoother insertion can be realized since there is no catch. In the modification shown in FIG. 29, the inner circumferential surface of the annular member 15' includes, from the front side, a small inner diameter cylindrical surface 15ia', a chamfered portion 15ib', an intermediate inner diameter cylindrical surface 15ic', and a second truncated conical inner surface. 15id', a four-sided flattened part 15ie', a large inner diameter cylindrical surface 15if', and a third truncated conical inner surface 15ig' are provided in this order. Three slits 15s' are provided as cutouts.

(Other aspects of the notch)
In the embodiment described above, the slit 115s was provided as the notch. That is, the notch was formed to penetrate from the inner circumferential side to the outer circumferential side of the annular member 115.

However, the notch is not limited to such a form, and may be formed as a thinner part (a part of the thickness is cut out) compared to the surrounding area. For example, a mode may be adopted in which a thin wall portion remains at the slit 115s.

FIG. 30(a) is a perspective view of such a modified annular member 15'', FIG. 30(b) is a plan view of the annular member 15'' of FIG. 30(a), and FIG. 30(c) is a perspective view of such a modified annular member 15''. ) is a side view of the annular member 15'' in FIG. 30(a), FIG. 30(d) is a bottom view of the annular member 15'' in FIG. 30(a), and FIG. 30(e) is a side view of the annular member 15'' in FIG. 30(a). 30(c) is a cross-sectional view taken along line AA of FIG. 30(c), FIG. 30(f) is a front view (view from the tip side) of the annular member 15'' of FIG. 30(a), and FIG. 30(g) 30(a) is a rear view of the annular member 15'' of FIG. 30(a).

As shown in FIGS. 30(a) to 30(g), the outer circumferential surface of the annular member 15'' includes, from the front side, a small outer diameter cylindrical surface 15a'' and a first truncated surface serving as a tapered contact surface. a conical outer surface 15b'', a medium outer diameter cylindrical surface 15c'', a second truncated conical outer surface 15d'' as a tapered contact surface, a first large outer diameter cylindrical surface 15e'', and a flange surface 15f as a stopper portion. "and the second large outer diameter cylindrical surface 15g" are provided in this order.

The annular member 15'' of the modified example is provided with three thin-walled portions 15t'' as cutouts. As shown in FIGS. 30(a) to 30(g), the three thin-walled portions 15t'' are placed at positions corresponding to the three slits 115s, that is, at equal intervals in the circumferential direction of the annular member 15'' ( (every 120°). Each of the three thin-walled portions 15t'' has a width of 0.8 mm and a wall thickness of 0.2 mm, and extends from the front end of the annular member 15'' in the axial direction to approximately the center of the second truncated conical outer surface 15d''. It is extended (maximum axial length 5.5 mm).

Even in such a modified example, when a load is applied to the first truncated conical outer surface 15b'' (abutment surface), the inner diameter of the annular member 15'' can be flexibly reduced, and the load can be reduced. When released, the inner diameter of the annular member 15'' can return elastically.

10 Retractable writing instrument (Patent Document 5)
11 Shaft cylinder 11ia Small inner diameter cylindrical surface 11ib First truncated conical inner surface 11ic Medium inner diameter cylindrical surface 11id Second truncated conical inner surface 11ie First large inner diameter cylindrical surface 11if Third truncated conical inner surface 11ig Second large inner diameter cylindrical surface 11ih Annular Protrusion 11m Front part 11r Rear part 13 Chip holder 13a Base end 13b First collar part 13c Second collar part 14 Chip 15 Annular member 15a Small outer diameter cylindrical surface 15b First truncated conical outer surface 15c Medium outer diameter cylindrical surface 15d Second External truncated conical surface 15e First large outer diameter cylindrical surface 15f Third truncated conical outer surface 15g Second large outer cylindrical surface 15ia Small inner cylindrical surface 15ib First truncated conical inner surface 15ic Medium inner cylindrical surface 15id Second truncated conical surface Inner surface 15ie Four-sided cylindrical surface 15if Large inner diameter cylindrical surface 15ig Third truncated conical inner surface 15s Slit 16 Coil spring 110 Retractable writing instrument 111 Shaft tube 111ia Small inner diameter cylindrical surface 111ib First truncated conical inner surface 111ic Medium inner diameter cylindrical surface 111id Second truncated end Conical inner surface 111ie First large inner diameter cylindrical surface 111if Circular ring surface 111ig Second large inner diameter cylindrical surface 111ih Annular projection 111m Front part 111r Rear part 111p Raised part 113 Chip holder 113a Base end part 113b First collar part 113c Second collar part 114 Tip 115 Annular member 115a Small outer diameter cylindrical surface 115b First truncated conical outer surface 115c Medium outer diameter cylindrical surface 115d Second truncated conical outer surface 115e First large outer diameter cylindrical surface 115f Flange surface (stopper part)
115g Second large outer diameter cylindrical surface 115ia Small inner diameter cylindrical surface 115ib First truncated conical inner surface 115ic Medium inner diameter cylindrical surface 115id Second truncated conical inner surface 115ie Four-sided removed portion 115if Large inner diameter cylindrical surface 115ig Third truncated conical inner surface 115s Slit 116 Coil spring 15' Annular member 15ia' Small inner diameter cylindrical surface 15ib' Chamfered portion 15ic' Medium inner diameter cylindrical surface 15id' Second truncated conical inner surface 15ie' Four-sided flattened portion 15if' Large inner diameter cylindrical surface 15ig' Third truncated conical inner surface 15s ' Slit 15'' Annular member 15a'' Small outer diameter cylindrical surface 15b'' First truncated conical outer surface 15c'' Medium outer diameter cylindrical surface 15d'' Second truncated conical outer surface 15e'' First large outer diameter cylindrical surface 15f'' Flange surface (stopper Department)
15g" Second large outer diameter cylindrical surface 15t" Thin wall portion 3 Front shaft 32 Main body 33 Gripping portion 4 Intermediate shaft 41 First elongated hole 42 Step portion 43 Cam portion 43a Cam tooth 43b Cam groove 44 Outward protrusion 5 Rear shaft 51 No. 2 long hole 52 mounting hole 53 friction part 54 inward protrusion 6 refill (cursive)
61 Pen nib 62 Ink storage tube 63 Tail plug 63a Air hole 63b Projection piece 63c Gap 63d Small diameter part 63e Large diameter part 63f Flange part 63g Engagement surface 63p Outward projection 63t Auxiliary taper part 7 Retractable rotating member 71 Projection 72 Projection part 72a Engagement surface 73 Contact portion 74 Annular auxiliary projection 74t Auxiliary contact surface 78 Outward projection 8 Knock member 81 Base 82 Shaft portion 82a Cam tooth 83 Clip 88 Inward projection

Claims (24)

a shaft cylinder having an opening at the front end;
a chip holder housed inside the barrel and movable in the axial direction of the barrel;
a chip fixed to the front end of the chip holder and retractable from the opening of the shaft cylinder as the chip holder moves;
an annular member that is loosely fitted into the inner periphery of the opening of the shaft cylinder and is movable in the axial direction of the shaft cylinder with respect to the shaft cylinder;
an elastic member capable of connecting the chip holder and the annular member so that they can move relative to each other;
Equipped with
A contact surface is formed on at least a portion of the outer periphery of the annular member, and the contact surface comes into contact with a portion of the inner surface of the shaft cylinder as the chip holder moves toward the front end side;
A notch is formed in a part of the annular member, and the inner diameter of the annular member is reduced when a load is applied to the abutting surface.
A guide surface is formed on a part of the inner surface of the shaft cylinder, and the guide surface comes into contact with the contact surface as the chip holder moves toward the front end side.
The contact surface receives the load from the guide surface as the chip holder moves toward the front end,
A part of the inner surface of the barrel is provided with a protrusion that protrudes toward the central axis of the barrel,
The rear surface of the raised portion is a surface perpendicular to the axial direction or a surface tapered toward the rear end,
A retractable writing instrument, characterized in that a stopper part is provided on a part of the outer periphery of the annular member, and the stopper part defines a frontward movement limit of the annular member by coming into contact with the raised part. The retractable writing instrument according to claim 1, wherein the raised portion is formed in an annular shape. The retractable writing instrument according to claim 1 or 2, wherein the stopper portion is formed as an annular flange portion. A plurality of the notches are arranged at equal intervals in the circumferential direction of the annular member,
The retractable writing instrument according to any one of claims 1 to 3, wherein each of the plurality of notches is a slit extending in the axial direction of the annular member. The abutment surface is tapered toward the front end,
The retractable writing instrument according to any one of claims 1 to 4, wherein the guide surface is also tapered toward the front end. The retractable writing instrument according to claim 5, wherein the abutting surface has a truncated conical surface. The retractable writing instrument according to any one of claims 1 to 6, wherein the elastic member is a coil spring. The annular member and the elastic member are fixed to each other,
the elastic member is connectable to an annular collar of the chip holder;
8. The retractable writing instrument according to claim 1, wherein the elastic member is separable from the annular collar of the tip holder. 9. The retractable writing instrument according to claim 1, wherein the contact surface and the guide surface are in constant contact with each other. The retractable writing instrument according to any one of claims 1 to 9, wherein the annular member projects forward from the opening of the barrel. The retractable writing instrument according to any one of claims 1 to 10, further comprising a soft member provided at the operation section for retracting and retracting the tip or at the rear of the barrel. further comprising a knocking member slidably provided in the front-rear direction with respect to the shaft cylinder,
The tip is moved back and forth so as to alternately protrude from and retract from the opening of the shaft cylinder each time the knocking member is moved forward,
The retractable writing instrument according to any one of claims 1 to 11, wherein the annular member is rotated with respect to the barrel each time the knock member is moved forward. . A recess that is capable of axially movably housing a chip holder having a chip fixed to the front end, has an opening at the front end, and allows the chip to emerge and retract from the opening as the chip holder moves. A barrel for a type writing instrument,
an annular member that is loosely fitted to the inner periphery of the opening of the shaft cylinder and is movable in the axial direction of the shaft cylinder with respect to the shaft cylinder;
an elastic member capable of connecting the chip holder and the annular member so that they can move relative to each other;
A contact surface is formed on at least a portion of the outer periphery of the annular member, and the contact surface comes into contact with a portion of the inner surface of the shaft cylinder as the chip holder moves toward the front end side;
A notch is formed in a part of the annular member, and the inner diameter of the annular member is reduced when a load is applied to the abutting surface.
A guide surface is formed on a part of the inner surface of the shaft cylinder, and the guide surface comes into contact with the contact surface as the chip holder moves toward the front end side.
The contact surface receives the load from the guide surface as the chip holder moves toward the front end,
A part of the inner surface of the barrel is provided with a protrusion that protrudes toward the central axis of the barrel,
The rear surface of the raised portion has a surface perpendicular to the axial direction or a surface tapered toward the rear end,
A barrel for a retractable writing instrument, characterized in that a flange portion is provided on a part of the outer periphery of the annular member and defines a forward movement limit of the annular member by coming into contact with the raised portion. The barrel of a retractable writing instrument according to claim 13, wherein the raised portion is formed in an annular shape. The barrel of a retractable writing instrument according to claim 13 or 14, wherein the stopper portion is formed as an annular flange portion. A plurality of the notches are arranged at equal intervals in the circumferential direction of the annular member,
The barrel for a retractable writing instrument according to any one of claims 13 to 15, wherein each of the plurality of notches is a slit extending in the axial direction of the annular member. The abutment surface is tapered toward the front end,
17. The barrel for a retractable writing instrument according to claim 13, wherein the guide surface is also tapered toward the front end. The barrel for a retractable writing instrument according to claim 17, wherein the abutting surface has a truncated conical surface. The barrel for a retractable writing instrument according to any one of claims 13 to 18, wherein the elastic member is a coil spring. The annular member and the elastic member are fixed to each other,
the elastic member is connectable to an annular collar of the chip holder;
The barrel for a retractable writing instrument according to any one of claims 13 to 19, wherein the elastic member is separable from the annular collar of the tip holder. The barrel for a retractable writing instrument according to any one of claims 13 to 20, wherein the contact surface and the guide surface are in constant contact with each other. The barrel for a retractable writing instrument according to any one of claims 13 to 21, wherein the annular member projects forward from the opening of the barrel. The barrel for a retractable writing instrument according to any one of claims 13 to 22, characterized in that a soft member is provided at the operating portion for operating the tip to protrude and retract, or at the rear of the barrel. . further comprising a knocking member slidably provided in the front-rear direction with respect to the shaft cylinder,
The tip can be moved back and forth so as to alternately protrude from and retract from the opening of the shaft cylinder each time the knocking member is moved forward,
The retractable writing instrument according to any one of claims 13 to 23, wherein the annular member is rotated with respect to the barrel each time the knock member is moved forward. Axial tube for.

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