Knock-type writing instrument

Abstract

To provide a knock type writing instrument capable of normal knocking operation while increasing the holding power of a clip.SOLUTION: A knock type writing instrument 1 includes a barrel 4, a hollow knock member 30 arranged at the rear end of the barrel 4, a rotor 40 whose rear portion is inserted into the knock member 30 and has a flexible portion, and a clip 50 integrally provided with the knock member 30 and configured to bias the outer surface of the barrel 4. The flexible portion is configured to be deformable so that the front end portion of the rotor 40 that acts via the knock member 30 inclined with respect to the central axis C1 of the barrel 4 by the biasing force of the clip 50 absorbs the pressing force that presses the inner surface of the barrel 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a knock-type writing instrument. [Background technology]

[0002] A so-called knock-type writing instrument is known, which has an operating part equipped with a knock member at the rear end of a barrel, and which switches between a writing state in which the writing part, which is the pen tip, protrudes from the tip of the barrel and a non-writing state in which the writing part is retracted into the barrel by performing a knock operation that presses the operating part forward against the biasing force of a spring arranged inside the barrel (for example, Patent Document 1). In the knock-type writing instrument, the knock operation causes the knock member (corresponding to the cam member in Patent Document 1) to move forward together with the rotor, causing the rotor to rotate. The knock-type writing instrument switches between a writing state and a non-writing state in response to the rotation of the rotor accompanying the knock operation.

[0003] In the knock-type writing implement of Patent Document 1, a clip is integrally provided at the rear end of the knock member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 104468 Summary of the Invention [Problem to be solved by the invention]

[0005] Since the clip holds articles such as paper between the clip and the barrel, it is preferable that the clip has a strong holding force. In order to strengthen the holding force of the clip, for example, the clip is configured to be biased against the barrel. This biasing force may cause problems with the knock operation. This will be described with reference to FIG. 6.

[0006] Fig. 6 is a vertical cross-sectional view of the rear end portion of a conventional knock type writing instrument 100. Specifically, Fig. 6(A) is a vertical cross-sectional view of the rear portion of the knock type writing instrument 100 in a non-writing state, and Fig. 6(B) is a vertical cross-sectional view of the rear portion of the knock type writing instrument 100 in a writing state.

[0007] Knock type writing instrument 100 has knock mechanism 110 inside rear barrel 103 that constitutes the barrel. Knock mechanism 110 has outer cam 120 (FIG. 6(B)), which is a cam protrusion provided on the inner surface of rear barrel 103, hollow knock member 130 located at the rear end of the barrel, rotor 140 whose rear portion is inserted into knock member 130, and clip 150 provided integrally with knock member 130.

[0008] The outer peripheral surface of the front side of the knock member 130 is provided with locking projections 131 at equal intervals in the circumferential direction. The front end surface of the knock member 130 is formed with a cam surface 132. The rotor 140 has a small diameter portion 141 arranged at the rear and inserted into the knock member 130, a large diameter portion 142 arranged in front of the small diameter portion 141 and a cam receiving surface 143 formed on the annular rear end surface of the large diameter portion 142. The cam receiving surface 143 has a shape complementary to the cam surface 132 of the knock member 130 so as to cooperate with the cam surface 132 of the knock member 130. The refill 106, which is biased backward by a spring (not shown), is inserted into the large diameter portion 142. The rotor 140 is given a rotational force by the cooperation of the cam surface 132 of the knock member 130 and the cam receiving surface 143 of the rotor 140, and rotates around the central axis. The rotor 140 also cooperates with the outer cam 120 to contribute to switching between the writing state and the non-writing state.

[0009] The clip 150 is fitted to the outer peripheral surface of the rear end of the knock member 130 via a fitting portion 151. A protruding ball portion 152 is provided at the front end of the clip 150 on the barrel side. The clip 150 biases the barrel via the ball portion 152. This allows the clip 150 to firmly hold an article between the barrel and the clip 150. However, due to the reaction force of the biasing force of the clip 150 against the barrel, the central axis C2 of the knock member 130 that is fitted to the knock member 130 via the fitting portion 151 is inclined relative to the central axis C1 of the knock-type writing instrument 100. Note that in the drawing, the inclination of the central axis C2 is exaggerated.

[0010] In the knock type writing instrument 100 in the non-writing state shown in FIG. 6(A), the connection between the knock member 130 and the rotor 140 is loose, so the influence of the inclination of the knock member 130 with respect to the rotor 140 is small. Therefore, the central axis C2 of the knock member 130 is inclined with respect to the central axis C1 of the knock type writing instrument 100, while the central axis of the rotor 140 is approximately aligned with the central axis C1 of the knock type writing instrument 100. On the other hand, in the knock type writing instrument 100 in the writing state shown in FIG. 6(B), the knock member 130 advances and the backward biasing force via the refill 106 becomes stronger, so that the knock member 130 and the rotor 140 are strongly coupled together. As a result, the rotor 140 is inclined in the same manner as the knock member 130. That is, the central axis of the rotor 140 is approximately aligned with the central axis C2 of the knock member 130 and is inclined with respect to the central axis C1 of the knock type writing instrument 100.

[0011] When the rotor 140 tilts, the front edge of the rotor 140, specifically the front edge of the large diameter portion 142 of the rotor 140, abuts against the inner surface of the barrel, specifically the inner surface of the rear barrel 103 shown by the X portion in FIG. 6(B). In short, the front end of the rotor 140 receives a pressing force from the inner surface of the barrel via the knock member 130, which is inclined with respect to the central axis C1 of the barrel by the biasing force of the clip 150. When the rotor 140 abuts against the barrel and receives a pressing force, not only does it become a resistance to the forward and backward movement of the rotor 140, but the rotor 140 may also be locked with the inner surface of the barrel. As a result, there is a risk that normal knocking operation cannot be performed.

[0012] Even if the clip is not configured to be biased against the barrel, it is possible to increase the frictional force with the article and the holding force by providing a protrusion similar to ball portion 152 on the outer surface of the barrel behind ball portion 152. However, in this case, providing a protrusion on the outer surface of the barrel makes it impossible to apply a design such as transfer printing to that portion of the barrel in a wide area and efficiently.

[0013] An object of the present invention is to provide a knock-type writing instrument that enables normal knocking operation while increasing the holding force of the clip. [Means for solving the problem]

[0014] According to one aspect of the present invention, there is provided a knock-type writing instrument comprising a barrel, a hollow knock member arranged at the rear end of the barrel, a rotor whose rear portion is inserted into the knock member and has a flexible portion, and a clip that is integral with the knock member and configured to bias the outer surface of the barrel, wherein the flexible portion is configured to be deformable so as to absorb the pressing force applied by the front end of the rotor acting through the knock member which is inclined with respect to the central axis of the barrel due to the biasing force of the clip to press against the inner surface of the barrel.

[0015] The flexible portion may be one or more slits provided in the rotor so as to extend along the axial direction or circumferential direction of the rotor. The flexible portion may be formed of a material softer than a portion of the rotor that is inserted into the knock member. The clip may be configured to bias the outer surface of the barrel by a front end portion of the clip. The clip may be provided with a ball portion at its front end portion. Effect of the Invention

[0016] According to the aspects of the present invention, a common effect is achieved in that a knock-type writing instrument that enables a normal knock operation while increasing the holding force of the clip is provided. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a side view of a knock-type writing instrument according to an embodiment of the present invention in a non-writing state. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the rear part of the knock-type writing instrument of FIG. 1 in a writing state. [Diagram 3] FIG. 3 is a perspective view of the rotor. [Figure 4] FIG. 4 is a perspective view of another rotor. [Diagram 5] FIG. 5 is a vertical cross-sectional view of yet another rotor. [Figure 6] FIG. 6 is a vertical cross-sectional view of the rear part of a conventional knock-type writing instrument. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Corresponding components are designated by common reference numerals throughout the drawings.

[0019] Fig. 1 is a side view of a knock-type writing instrument 1 according to an embodiment of the present invention in a non-writing state, and Fig. 2 is a vertical cross-sectional view of the rear part of the knock-type writing instrument 1 in Fig. 1 in a writing state. Also, Fig. 3 is a perspective view of a rotor 40.

[0020] The knock type writing instrument 1 has a barrel 4 formed in a cylindrical shape and equipped with a front shaft 2 and a rear shaft 3, a refill 6 which is a writing body arranged in the barrel 4 and equipped with a writing part 5 at one end, a spring 7 which biases the refill 6 rearward, and a knock mechanism 10 arranged at the rear end of the barrel 4. The knock mechanism 110 has an outer cam 120 (FIG. 2) which is a cam protrusion arranged on the inner surface of the rear shaft 103, a hollow knock member 30 arranged at the rear end of the barrel 4, a rotor 40 whose rear part is inserted into the knock member 30, and a clip 50 which is integrally arranged with the knock member 30. In this specification, in the axial direction of the knock type writing instrument 1, the writing part 5 side is defined as the "front" side, and the opposite side to the writing part 5 side is defined as the "rear" side.

[0021] The knock member 30 has locking projections 31 provided at equal intervals in the circumferential direction on the outer circumferential surface on the front side thereof. The knock member 30 has a cam surface 32 formed on its front end surface.

[0022] As shown in FIG. 3, the rotor 40 has a small diameter portion 41 arranged at the rear and inserted into the knock member 30, a large diameter portion 42 arranged in front of the small diameter portion 41 and a cam receiving surface 43 formed on the annular rear end surface of the large diameter portion 42. The cam receiving surface 43 has a shape complementary to the cam surface 32 of the knock member 30 so as to cooperate with the cam surface 32. The large diameter portion 42 is formed in a cylindrical shape. The large diameter portion 42 has four slits 44 extending from the front end toward the rear, i.e., extending along the axial direction, formed at equal intervals along the circumferential direction. The refill 6 biased backward by the spring 7 is inserted into the large diameter portion 42. The rotor 40 is given a rotational force by the cooperation of the cam surface 32 of the knock member 30 and the cam receiving surface 43 of the rotor 40, and rotates around the central axis. The rotor 40 also cooperates with the outer cam 20 to contribute to switching between the writing state and the non-writing state.

[0023] As shown in FIG. 2, the clip 50 is fitted to the outer peripheral surface of the rear end of the knock member 30 via a fitting portion 51. A protruding ball portion 52 is provided at the front end of the clip 50 on the barrel side. The clip 50 biases the barrel 4, specifically the rear barrel 3, via the ball portion 52. This allows the clip 50 to firmly hold an article between the clip 50 and the rear barrel 3. On the other hand, due to the reaction force of the biasing force of the clip 50 against the rear barrel 3, the central axis C2 of the knock member 30 that is fitted to the clip 50 via the fitting portion 51 is inclined with respect to the central axis C1 of the knock-type writing instrument 1. Note that the inclination of the central axis C2 is exaggerated in the drawing.

[0024] In the knock-type writing instrument 1 in the writing state shown in Fig. 2, the knock member 30 advances, and thus the rearward biasing force of the spring 7 via the refill 6 becomes stronger, and the knock member 30 and the rotor 40 are strongly connected. As a result, the rotor 40 tilts in the same manner as the knock member 30. In short, the front end of the rotor 40, particularly the large diameter portion 42, receives a pressing force from the inner surface of the barrel 4 via the knock member 30 which tilts with respect to the central axis C1 of the barrel 4 due to the biasing force of the clip 50.

[0025] As described above, the large diameter portion 42 has a plurality of slits 44, so that the portion of the large diameter portion 42 between the adjacent slits 44 is defined as a cantilever beam and is easily bent along the radial direction. Therefore, the large diameter portion 42 as a whole has flexibility in the radial direction. Therefore, even if the above-mentioned pressing force is applied to the large diameter portion 42 of the rotor 40, the large diameter portion 42 elastically deforms as shown in part A of FIG. 2 and absorbs the pressing force. As a result, even if the knock operation is performed on the knock type writing instrument 1 and the rotor 40 moves in the forward and backward directions, the rotor 40 will not engage with the inner surface of the barrel 4. Therefore, according to the knock type writing instrument 1, a normal knock operation is possible while increasing the holding force of the clip 50.

[0026] Only one slit 44 may be formed, or two, three, five or more slits may be formed. The slit 44 is preferably formed to have a length equal to or greater than half the axial length of the large diameter portion 42. The above-mentioned slit 44 is formed so as to extend rearward from the front end of the large diameter portion 42 of the rotor 40, but it may be an elongated hole extending rearward from near the front end instead of from the front end. In this specification, the elongated hole is also included in the slit.

[0027] In the rotor 40, the large diameter portion 42 in which the slits 44 are formed, more specifically, the portion that comes into contact with the inner surface of the shaft tube 4 due to the tilt of the rotor 40, constitutes a flexible portion. In short, the flexible portion absorbs the pressing force against the shaft tube 4 caused by the tilt of the central axis of the rotor 40 by deforming or bending. Other embodiments of the flexible portion in the rotor will be described with reference to Figs. 4 and 5.

[0028] FIG. 4 is a perspective view of another rotor 60. The rotor 60 has a small diameter portion 61, a large diameter portion 62 formed in a cylindrical shape, and a cam receiving surface 63, similar to the rotor 40 shown in FIG. 3. Three slits 64 extending in the circumferential direction are formed in the large diameter portion 62 at equal intervals along the axial direction. Adjacent slits 64 are arranged so as to correspond to symmetrical positions rotated 180 degrees around the central axis of the rotor 60. By forming the slits 64 in the large diameter portion 62 of the rotor 60, the large diameter portion 62 as a whole has flexibility to bend in the axial direction. Therefore, in the rotor 60, the large diameter portion 62 in which the slits 64 are formed constitutes a flexible portion.

[0029] When the large diameter portion 62 bends, the width of the slits 64 arranged on the inside of the bend is reduced by elastic deformation, while the width of the slits 64 arranged on the outside of the bend is expanded by elastic deformation. Therefore, even if the above-mentioned pressing force is applied to the large diameter portion 62 of the rotor 60, the large diameter portion 62 is elastically deformed and absorbs the pressing force.

[0030] The number of slits 64 may be one, two, three, five or more. Adjacent slits 64 may be arranged so as to correspond to a position rotated 90 degrees around the central axis of the rotor 60, or may be arranged so as to correspond to a position rotated 45 degrees or 60 degrees. Adjacent slits 64 may be arranged so as to correspond to a position rotated around the central axis of the rotor 60 by an angle obtained by dividing 360 degrees by the number of slits 64. Specifically, when three slits 64 are formed, they may be arranged so as to correspond to a position rotated 120 degrees. The slits 64 are preferably an arc with a central angle of 180 degrees or more.

[0031] In the above-described embodiment, the flexible portion is one or more slits provided in the rotor, specifically in the large diameter portion, so as to extend along the axial direction or circumferential direction of the rotor.

[0032] FIG. 5 is a longitudinal sectional view of yet another rotor 70. The rotor 70 has a small diameter portion 71, a large diameter portion 72 formed in a cylindrical shape, and a cam receiving surface 73, similar to the rotor 40 shown in FIG. 3. The rotor 70 is formed of two materials, for example, by two-color molding. Specifically, as shown in FIG. 5, a part of the large diameter portion 72 including the small diameter portion 71 and the cam receiving surface 73 is formed of a first material M1, and the remaining part of the large diameter portion 72 is formed of a second material M2. The second material M2 is softer than the first material M1. Therefore, the part of the large diameter portion 72 formed of the second material M2 constitutes a flexible portion. The flexible portion is softer than the part inserted into the knock member 30, i.e., the small diameter portion 71. Therefore, even if the above-mentioned pressing force is applied to the large diameter portion 72 of the rotor 70, the large diameter portion 72 elastically deforms and absorbs the pressing force. The rotor 70 may be formed by combining the first material M1 and the second material M2 by a method other than two-color molding, such as fitting or bonding.

[0033] As described above, the flexible portion includes not only a portion that is easily deformed by slits or the like, but also a portion that is easily deformed by the selection of materials, thereby reducing the rigidity of the rotor and absorbing the pressing force received from the inner surface of the barrel. In a knock-type writing instrument, the rotor has a flexible portion, which increases the holding force of the clip and enables normal knocking operation.

[0034] Although the clip 50 has the ball portion 52, it may have any configuration as long as it is configured so that the front end portion of the clip 50 presses against the outer surface of the barrel 4. Therefore, the clip 50 does not have to have the ball portion 52.

[0035] The refill 6 may be a ballpoint pen, or other types of writing implements such as a marking pen, a touch pen, an eraser, etc. In addition, the clip 50 and a part or the whole of the fitting portion 51 may be an erasing portion that erases handwriting made by a knock-type writing implement.

[0036] The refill 6 may be a ballpoint pen containing thermochromic ink. Here, the thermochromic ink refers to ink that has the property of maintaining a predetermined color (first color) at room temperature (e.g., 25°C), changing to another color (second color) when heated to a predetermined temperature (e.g., 60°C), and then returning to the original color (first color) when cooled to a predetermined temperature (e.g., -5°C). In a thermochromic writing instrument using thermochromic ink, the second color is made colorless, and the term "erasing" refers to heating a line drawn in the first color (e.g., red) to make it colorless. Therefore, the friction member, which is the erasing part, rubs against the writing surface on which the line was drawn to generate frictional heat, thereby changing the drawn line to colorless, that is, erasing it. It should be noted that the second color may be a color other than colorless. [Explanation of symbols]

[0037] 1. Knock-type writing implement 2 front axle 3 rear axle 4 shaft cylinder 5 Writing section 6 Refills 7. Spring 10 Knock mechanism 20 Outer Cam 30 Knock parts 31 Locking protrusion 32 Cam surface 40 Rotor 41 Small diameter section 42 Large diameter section 43 Cam receiving surface 44 Slit 50 clips 51 Fitting part

Claims

1. a barrel, a hollow knock member disposed at a rear end of the barrel, a rotor having a rear portion inserted into the knock member and a flexible portion, and a clip integrally provided with the knock member and configured to bias an outer surface of the barrel, A knock-type writing instrument, characterized in that the flexible portion is configured to be deformable so as to absorb the pressing force applied by the front end of the rotor to the inner surface of the barrel through the knock member, which is inclined relative to the central axis of the barrel due to the biasing force of the clip.

2. 2. The knock type writing instrument according to claim 1, wherein the flexible portion is one or more slits provided in the rotor so as to extend along the axial direction or circumferential direction of the rotor.

3. 2. The knock type writing implement according to claim 1, wherein the flexible portion is made of a material softer than a material of a portion of the rotor that is inserted into the knock member.

4. 4. The knock-type writing implement according to claim 1, wherein a front end of the clip is configured to bias an outer surface of the barrel.

5. 5. The knock-type writing implement according to claim 4, wherein a ball portion is provided at a front end portion of the clip.

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