Notebook

Abstract

To provide a writing instrument that prevents a rotor from coming off when replacing the refill.SOLUTION: A writing tool 1 includes a cylindrical barrel 2, an inner cylinder 10 arranged inside the barrel 2, and a rotor 12 arranged inside the inner cylinder 10. The inner cylinder 10 is formed with an elastically deformed portion 10e2 that protrudes inward from the outer diameter of the rotor 12 when placed in the barrel 2 at the position on the tip side from the rotor 12 in the assembled state.SELECTED DRAWING: Figure 12C

Description

Technical Field

[0001] The present invention relates to a writing instrument, and more particularly to a writing instrument including a cylindrical shaft tube, an inner tube disposed inside the shaft tube, and a rotor disposed inside the inner tube.

Background Art

[0002] Conventionally, regarding writing instruments such as knock-type ballpoint pens, an inner tube is attached to the rear end portion of a cylindrical shaft tube, a knock member is inserted from the rear end of the inner tube, and by pressing this knock member, an internal rotor rotates to switch the protrusion and retraction of the pen tip. A can knock-type writing instrument is known.

[0003] Regarding such a writing instrument, for example, Patent Document 1 discloses a configuration in which a protrusion is formed on the outer peripheral surface of the inner tube, a diameter stop portion is formed on the shaft tube, and when the inner tube is disposed inside the shaft tube, the protrusion is locked to the diameter stop portion to fix the inner tube to the shaft tube.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the writing instrument described in Patent Document 1, when the user disassembles the writing instrument when replacing the refill, the rotor comes off from the inner tube or the shaft tube, and there is a problem that the rotor is lost.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a writing instrument in which the rotor does not come off even when the writing instrument is disassembled when replacing the refill or the like.

Means for Solving the Problems

[0007] The writing instrument of the present invention comprises a cylindrical barrel, an inner cylinder disposed inside the barrel, and a rotor disposed inside the inner cylinder, wherein the inner cylinder has an elastically deformable portion formed at a position closer to the tip of the rotor in the assembled state, which protrudes inward from the outer diameter of the rotor when placed inside the barrel. According to the present invention with the above configuration, when the inner cylinder is placed inside the barrel, the elastically deformable portion protrudes inward, beyond the outer diameter of the rotor. As a result, even when the writing instrument is disassembled, such as when replacing the refill, the rotor comes into contact with the elastically deformable portion, preventing the rotor from detaching from the barrel.

[0008] In the present invention, preferably, a reduced diameter portion is formed on the inner circumferential surface of the shaft cylinder, and the elastically deformable portion protrudes inward as its outer circumferential surface comes into contact with the reduced diameter portion. According to the present invention with the above configuration, by arranging the inner cylinder inside the shaft cylinder, the elastically deformable portion can be made to protrude inward, making assembly easier and preventing the rotor from detaching without complicating the structure of the inner cylinder.

[0009] In the present invention, preferably, the inner cylinder has a stepped portion on its outer circumference, and when the inner cylinder is positioned inside the shaft cylinder, if an extraction force is applied to the inner cylinder, the stepped portion engages with the reduced diameter portion and resists the extraction force. According to the present invention with the above configuration, the stepped portion engages with the reduced diameter portion, so the inner cylinder can be fixed to the shaft cylinder.

[0010] In the present invention, preferably, the elastically deformable portion is in the shape of a cantilever beam extending toward the rear. According to the present invention with the above configuration, the inner cylinder can be configured to protrude inward when it is placed inside the shaft cylinder with a simple configuration.

[0011] In the present invention, preferably, a clip member is provided along the shaft cylinder, and a clip holding portion is formed by the shaft cylinder and the inner cylinder to hold the clip member. According to the present invention with the above configuration, the clip member can be attached easily.

[0012] In the present invention, preferably, the clip holding portion has a through hole, at least a part of the clip member is made of wire, the portion made of wire is arranged and held in the through hole, and the through hole is formed at the interface between the shaft cylinder and the inner cylinder. According to the present invention with the above configuration, the clip member is held by the through hole, preventing it from easily coming off. Furthermore, since the through hole is located at the interface between the shaft and the inner cylinder, the clip member can be easily placed inside the through hole. [Effects of the Invention]

[0013] According to the present invention, a writing instrument is provided in which the rotor does not come off when replacing the refill, etc. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view showing a writing instrument according to a first embodiment of the present invention. [Figure 2] This is a front view showing a writing instrument according to a first embodiment of the present invention. [Figure 3] This is a side view showing a writing instrument according to the first embodiment of the present invention. [Figure 4] Figure 1 is a cross-sectional view along the axial direction showing the barrel of the writing instrument. [Figure 5A] This is a perspective view showing the rear barrel of a writing instrument according to the first embodiment of the present invention. [Figure 5B] This is a front view showing the rear barrel of a writing instrument according to a first embodiment of the present invention. [Figure 5C] This is a side view showing the rear barrel of a writing instrument according to the first embodiment of the present invention. [Figure 5D] Figure 5C shows a cross-sectional view of the DD section of the rear barrel of a writing instrument according to the first embodiment of the present invention. [Figure 5E] Figure 5B shows a cross-sectional view of the EE section of the rear barrel of a writing instrument according to a first embodiment of the present invention. [Figure 5F] It is a front view showing the rear shaft cylinder of the writing instrument according to the first embodiment of the present invention. [Figure 5G] It is a rear view showing the rear shaft cylinder of the writing instrument according to the first embodiment of the present invention. [Figure 6A] It is a perspective view showing the inner cylinder of the writing instrument shown in FIG. 1. [Figure 6B] It is a front view showing the inner cylinder of the writing instrument shown in FIG. 1. [Figure 6C] It is a right side view showing the inner cylinder of the writing instrument shown in FIG. 1. [Figure 6D] It is a left side view showing the inner cylinder of the writing instrument shown in FIG. 1. [Figure 6E] It shows the inner cylinder of the writing instrument shown in FIG. 1 and is a sectional view taken along the line E-E of FIG. 6B. [Figure 6F] It shows the inner cylinder of the writing instrument shown in FIG. 1 and is a sectional view taken along the line F-F of FIG. 6C. [Figure 6G] It shows the inner cylinder of the writing instrument shown in FIG. 1 and is a sectional view taken along the line G-G of FIG. 6C. [Figure 6H] It shows the inner cylinder of the writing instrument shown in FIG. 1 and is a sectional view taken along the line H-H of FIG. 6C. [Figure 7A] It is a perspective view showing the clip member of the writing instrument shown in FIG. 1. [Figure 7B] It is a front view showing the clip member of the writing instrument shown in FIG. 1. [Figure 7C] It is a side view showing the clip member of the writing instrument shown in FIG. 1. [Figure 8A] It is a perspective view (part 1) for explaining a method of attaching the clip member to the inner cylinder and attaching the inner cylinder to the rear shaft cylinder in the writing instrument according to the first embodiment of the present invention. [Figure 8B] It is a side view corresponding to FIG. 8A. [Figure 9A] It is a perspective view (part 2) for explaining a method of attaching the clip member to the inner cylinder and attaching the inner cylinder to the rear shaft cylinder in the writing instrument according to the first embodiment of the present invention. [Figure 9B] It is a side view corresponding to FIG. 9A. [Figure 10A]This is a perspective view (part 3) illustrating a method for attaching the clip member to the inner cylinder and attaching the inner cylinder to the rear barrel of a writing instrument according to the first embodiment of the present invention. [Figure 10B] This is a side view corresponding to Figure 10A. [Figure 11A] This is a perspective view (part 4) illustrating a method for attaching the clip member to the inner cylinder and attaching the inner cylinder to the rear barrel of a writing instrument according to the first embodiment of the present invention. [Figure 11B] This is a side view corresponding to Figure 11A. [Figure 12A] This is a cross-sectional view corresponding to Figure 4, showing the inner cylinder with the clip member attached to it, mounted on the rear barrel, and the knock member and rotor attached to it, in the writing instrument according to the first embodiment of the present invention. [Figure 12B] Figure 12A is a cross-sectional view of BB. [Figure 12C] Figure 12B is an enlarged cross-sectional view of section C. [Figure 12D] Figure 12A is a cross-sectional view of the DD. [Modes for carrying out the invention]

[0015] Hereinafter, a writing instrument according to the first embodiment of the present invention will be described in detail with reference to the drawings. In each embodiment, the side from which the tip of the refill extends and retracts is referred to as the tip side, front side, or forward side, and the side from which the knock part of the extension / retraction mechanism extends is referred to as the rear end side or rear. The axial direction of the writing instrument is referred to as the longitudinal direction or axial direction. The direction perpendicular to the axial direction of the writing instrument is referred to as the radial direction, the direction close to the shaft is referred to as the radially inward direction, and the direction away from the shaft is referred to as the radially outward direction.

[0016] Figures 1 to 3 show a writing instrument according to the first embodiment of the present invention, where Figure 1 is a perspective view, Figure 2 is a front view, and Figure 3 is a side view. Figure 4 is a cross-sectional view along the axial direction showing the barrel of the writing instrument shown in Figure 1. The writing instrument 1 according to this embodiment is a so-called knock-type ballpoint pen, and by pressing the knock member 16 at the rear end, it is possible to switch between a state in which the tip portion 4a of the refill member 4 protrudes from the front of the barrel 2 and a state in which the tip portion 4a of the refill member 4 is housed inside the barrel 2.

[0017] As shown in Figures 1 to 4, the writing instrument 1 of this embodiment comprises a writing instrument body 7 and a clip member 8 held on the side of the writing instrument body 7. The clip member 8 is held in a clip holding portion 18 formed on the rear side of the writing instrument body 7. The writing instrument body 7 comprises a cylindrical, elongated barrel 2, a refill member 4 housed inside the barrel 2, and a retractable mechanism 6 provided at the rear end of the barrel 2. The retractable mechanism 6 comprises an inner cylinder 10, a rotor 12, a spring member 14, and a knock member 16.

[0018] The barrel 2 is formed in a cylindrical shape with a tapered tip. The barrel 2 is formed by connecting a front barrel 2A at the front end and a rear barrel 2B at the rear end. Figures 5A to 5G show the rear barrel of a writing instrument according to the first embodiment of the present invention, where Figure 5A is a perspective view, Figure 5B is a front view, Figure 5C is a side view, Figure 5D is a cross-sectional view of DD in Figure 5C, Figure 5E is a cross-sectional view of EE in Figure 5B, Figure 5F is a view from the front, and Figure 5G is a view from the rear. As shown in Figure 4, a thread 2A1 is formed on the outer circumferential surface of the rear end of the front barrel 2A. Also, as shown in Figures 5A to 5G, a thread 2B1 is formed on the inner circumferential surface of the rear barrel 2B. The rear end of the front shaft cylinder 2A enters inward from the front end side of the rear shaft cylinder 2B, and the threads 2A1 of the front shaft cylinder 2A and the threads 2B1 of the rear shaft cylinder 2B are screwed together, thereby connecting the front shaft cylinder 2A and the rear shaft cylinder 2B and forming the shaft cylinder 2. A front opening 2a is formed at the tip of the front shaft cylinder 2A. A rear opening 2b is formed at the rear end of the rear shaft cylinder 2B.

[0019] A pair of reduced-diameter portions 2c are formed on the inner surface of the rear end of the rear shaft cylinder 2B, projecting radially inward. The reduced-diameter portions 2c are rectangular in shape when viewed from the radially inward, and have an inclined surface at their rear end. The pair of reduced-diameter portions 2c are positioned opposite each other across the central axis.

[0020] Furthermore, a notch 2d is formed at the rear end edge of the rear shaft cylinder 2B, corresponding to the shape of the extension 10b1 of the inner cylinder 10, which will be described later. A first clip holding portion 2e is formed at the front end of the notch 2d. The first clip holding portion 2e comprises a base portion 2e1 erected on the outer circumferential surface of the rear shaft cylinder 2B and an engaging portion 2e2 connected to the base portion 2e1. The radially outer surface of the base portion 2e1 is formed flat. The rear surface of the base portion 2e1 is inclined to extend forward in the radially outward direction. A recess 2e3 is formed on the radially outer surface of the base portion 2e1, extending from one lateral edge to the midpoint in the width direction. The engaging portion 2e2 is erected at the front end of the radially outer surface of the base portion 2e1. The radially outer surface of the engaging portion 2e2 is formed flat, and the rear end of the engaging portion 2e2 is inclined forward in the radially inward direction.

[0021] Figures 6A to 6H show the inner cylinder of the writing instrument shown in Figure 1, where Figure 6A is a perspective view, Figure 6B is a front view, Figure 6C is a right side view, Figure 6D is a left side view, Figure 6E is a cross-sectional view of Figure 6B EE, Figure 6F is a cross-sectional view of Figure 6C FF, Figure 6G is a cross-sectional view of Figure 6C GG, and Figure 6H is a cross-sectional view of Figure 6C HH. As shown in Figures 6A to 6H, the inner cylinder 10 comprises a cylindrical body portion 10a, a rear end portion 10b connected to the rear end of the body portion 10a, and a second clip holding portion 10c connected to the rear end of the body portion 10a. These body portion 10a, rear end portion 10b, and second clip holding portion 10c are integrally molded.

[0022] The main body portion 10a is substantially cylindrical, and its outer diameter is slightly smaller than the inner diameter of the shaft cylinder 2. A recess 10d is formed on the front side of the main body portion 10a, which is recessed radially inward, and the peripheral edge of the recess 10d is formed as a stepped portion. Inside the recess 10d, a base portion 10e1 is formed along the front edge of the recess 10d, and an elastically deformable portion 10e2 is formed extending rearward from the base portion 10e1. The inner circumferential surface of the base portion 10e1 is the same cylindrical surface as the inner circumferential surface of the main body portion 10a, and the outer circumferential surface of the base portion 10e1 is a cylindrical surface with a smaller diameter than the main body portion 10a. The elastically deformable portion 10e2 is the same cylindrical surface as the base portion 10e1 and is formed in a cantilever shape extending rearward from the rear edge of the base portion 10e1. A convex portion 10e3 is formed at the tip of the base portion 10e1, projecting radially outward. The rear and both circumferential sides of the base 10e1 are surrounded by through holes 10e4.

[0023] Furthermore, a cam portion 10f (Figure 6E) is formed on the inner circumferential surface of the rear end of the main body portion 10a. The cam portion 10f works in cooperation with the cam portion 12b of the rotor 12 to press the knock member 16, thereby rotating the rotor 12 and switching between a state in which the brush tip portion 4a of the refill member 4 protrudes from the tip opening 2a of the barrel 2 and a state in which it is housed inside the barrel 2. A well-known configuration can be adopted for the cam portion 10f of the inner cylinder 10 and the cam portion 12b of the rotor 12. In this embodiment, the cam portion 10f of the inner cylinder 10 has a convex portion extending forward and a concave portion formed between the convex portion so as to extend backward.

[0024] The rear end portion 10b is formed in an annular shape, and its outer diameter is approximately equal to the outer diameter of the shaft cylinder 2. A circular through-hole is formed in the rear end portion 10b, extending through in the front-rear direction. The rear end portion 10b also includes an extension portion 10b1 that extends forward along the outer circumferential surface of the main body portion 10a.

[0025] The second clip-holding portion 10c is provided continuously with the front end of the extension portion 10b1 and is formed in a columnar shape that extends laterally. Both sides of the second clip-holding portion 10c in the lateral direction (left-right direction in Figure 6B) are formed parallel to each other.

[0026] The second clip holding portion 10c has an upright portion 10c1 erected radially outward from the main body portion 10a, and an extension portion 10c2 continuously provided at the radially outer tip of the upright portion 10c1. The front surface of the upright portion 10c1 is inclined forward toward the radially outward direction. A projection portion 10c3 is formed on the portion of the extension portion 10c2 that is in front of the upright portion 10c1, projecting radially inward. A first recess 10g is formed between the upright portion 10c1 and the projection portion 10c3, and at the front corner of the connection portion with the extension portion 10c2. A second recess 10h is formed at the rear corner of the connection portion between the upright portion 10c1 and the extension portion 10c2. The front surface of the projection portion 10c3 is inclined rearward toward the radially outward direction.

[0027] The first recess 10g is open radially inward and penetrates laterally (left-right direction in Figure 6B). The first recess 10g has a semicircular cross-section on its radially outer side (bottom) and a rectangular cross-section on its radially inner side, resulting in an overall U-shaped cross-section. The first recess 10g has a relief portion formed by widening the diameter of one side (the right side in Figure 6F) compared to the other side (the other side in Figure 6F). The second recess 10h is open rearward and penetrates laterally.

[0028] The rotor 12 has a rear base end 12a and a front cam portion 12b. The base end 12a is formed in a cylindrical shape, and its outer diameter is smaller than the inner diameter of the knock member 16. The cam portion 12b is also formed in a cylindrical shape, and its outer diameter is slightly smaller than the inner diameter of the main body portion 10a of the inner cylinder 10. The outer surface of the cam portion 12b has a convex portion extending towards the rear and a concave portion formed between the convex portion so as to extend towards the front.

[0029] The knock member 16 is formed in a cylindrical shape with its upper end closed and its lower end open. The outer diameter of the knock member 16 is approximately equal to the inner diameter of the through hole in the rear end 10b of the inner cylinder 10. In addition, a projection 16a is formed on the lower end of the outer circumferential surface of the knock member 16, projecting radially outward along the circumferential direction.

[0030] The spring member 14 has its rear end in contact with the front end of the refill member 4, and its front end in contact with the front end of the barrel 2. As a result, the spring member 14 biases the refill member 4 toward the rear.

[0031] In its assembled state, the inner cylinder 10 has its main body portion 10a inserted through the rear end opening 2b of the barrel 2 and positioned inside the barrel 2, with its rear end portion 10b abutting against the rear end edge of the barrel 2. The knock member 16 is inserted from the front into a through hole in the rear end portion 10b of the inner cylinder 10 and protrudes to the rear of the inner cylinder 10, with its projection 16a positioned inside the main body portion 10a of the inner cylinder 10. The rotor 12 has its base end portion 12a inserted from the front inside the knock member 16, with the tip edge of the knock member 16 abutting against the rear end surface of the cam portion 12b of the rotor 12. The tip surface of the cam portion 12b of the rotor 12 also abuts against the refill member 4. As a result, the rotor 12 and the knock member 16 are biased towards the rear via the refill member 4.

[0032] In this state, by pushing in the knocking member 16, the rotor 12 rotates, switching between a state where the protrusion of the cam portion 12b of the rotor 12 is inserted into the recess of the cam portion 10f of the inner cylinder 10, and a state where the tip of the protrusion of the cam portion 10f of the inner cylinder 10 and the tip of the protrusion of the cam portion 12b of the rotor 12 are in contact. This allows switching between a state where the brush tip portion 4a of the refill member 4 is housed inside the barrel 2 and a state where it protrudes from the tip of the barrel 2.

[0033] Figures 7A to 7C show the clip member of the writing instrument shown in Figure 1, with Figure 7A being a perspective view, Figure 7B a front view, and Figure 7C a side view. In Figures 7A to 7C, the clip member is shown removed from the inner cylinder. As shown in Figures 7A to 7C, the clip member 8 is formed by bending a single metal wire, such as stainless steel. The clip member 8 has a U-shaped tip 8A, a U-shaped rear end 8C, and an intermediate part 8B between the tip 8A and the rear end 8C.

[0034] The tip portion 8A is composed of the front portion of the first vertical portion 8b, the front portion of the second vertical portion 8c, and a first arc-shaped portion 8a connecting the front end of the first vertical portion 8b and the front end of the second vertical portion 8c. The first vertical portion 8b extends from the right end of the first arc-shaped portion 8a (right side in Figure 7B) toward the rear to the intermediate portion 8B. The second vertical portion 8c extends from the left end of the first arc-shaped portion 8a (left side in Figure 7B) toward the rear, beyond the intermediate portion 8B to the rear end portion 8C.

[0035] The rear end portion 8C is composed of the rear end portion of the second longitudinal portion 8c, a second arc-shaped portion 8d extending in an arc shape to the right (right side in Figure 7B) from the rear end portion of the second longitudinal portion 8c, and a third longitudinal portion 8e extending forward from the right end (right side in Figure 7B) of the second arc-shaped portion 8d.

[0036] The intermediate section 8B includes a first end 8f extending to the left (left side in Figure 7B) from the front end of the third vertical section 8e, and a second end 8g extending to the left (left side in Figure 7B) from the rear end of the first vertical section 8b. A bent portion 8h is formed at the tip of the second end 8g, which is inclined forward to the left.

[0037] With the clip member 8 removed from the inner cylinder 10, the first vertical portion 8b is inclined radially outward toward the rear (to the left in Figure 7C) with respect to the direction in which the second vertical portion 8c extends. Therefore, the first end portion 8f is located closer to the writing instrument body than the second end portion 8g.

[0038] When assembling the writing instrument of this embodiment, the clip member is first attached to the inner cylinder. Figures 8A to 11A are perspective views illustrating the method of attaching the clip member to the inner cylinder and attaching the inner cylinder to the rear barrel of the writing instrument of the first embodiment of the present invention. Figures 8B to 11B are side views corresponding to Figures 8A to 11A, respectively.

[0039] As shown in Figures 8A and 8B, in order to attach the clip member 8 to the inner cylinder 10, first, as indicated by the arrows in the figures, move the clip member 8 forward and insert the first end portion 8f into the second recess 10h from the rear.

[0040] Next, as shown in Figures 9A and 9B, the second end 8g of the clip member 8 is pressed radially inward toward the inner cylinder 10. Then, the second end 8g is fitted into the first recess 10g from the radially inward side. At this time, the bent portion 8h is fitted so that it is located in the enlarged portion of the first recess 10g.

[0041] Next, as shown in Figures 10A and 10B, the inner cylinder 10 is moved forward as indicated by the arrows in the figures, so that the extended portion 10b1 of the inner cylinder 10 fits into the notch 2d of the rear shaft cylinder 2B, and is inserted into the rear end opening 2b of the rear shaft cylinder 2B. By positioning the inner cylinder 10 so that the extended portion 10b1 of the inner cylinder 10 fits into the notch 2d of the rear shaft cylinder 2B, the recess 10d of the inner cylinder 10 is aligned axially with the reduced diameter portion 2c of the rear shaft cylinder 2B.

[0042] At this time, as shown in Figures 11A and 11B, when the rear end portion 8C of the clip member 8 is pushed radially inward toward the rear shaft cylinder 2B, the intermediate portion 8B held by the second clip holding portion 10c rotates around the pivot point, and the tip portion 8A of the clip member 8 moves radially outward so that it separates from the rear shaft cylinder 2B. Then, when the inner cylinder 10 is inserted forward in this state, the front edge of the inner cylinder 10 can pass over the reduced diameter portion 2c because the rear portion of the reduced diameter portion 2c is formed as an inclined surface. The inner cylinder 10 is inserted until the inclined surface on the front side of the upright portion 10c1 of the second clip holding portion 10c of the inner cylinder 10 comes into contact with the rear inclined surface of the base portion 2e1 of the rear shaft cylinder 2B. As a result, the reduced diameter portion 2c of the rear shaft cylinder 2B enters into the recess 10d of the inner cylinder 10. As a result, even if an outward pulling force acts on the inner cylinder 10 toward the rear shaft cylinder 2B, the front edge of the reduced-diameter portion 2c of the rear shaft cylinder 2B comes into contact with the stepped portion of the front edge of the recess 10d of the inner cylinder 10, preventing the inner cylinder 10 from separating from the rear shaft cylinder 2B. Furthermore, the radial inner surface of the reduced-diameter portion 2c of the rear shaft cylinder 2B comes into contact with the convex portion 10e3 formed on the elastically deformable portion 10e2, causing the elastically deformable portion 10e2 to curve radially inward. As a result, the inner edge of the rear end of the elastically deformable portion 10e2 protrudes inward beyond the outer diameter of the cam portion 12b of the rotor 12.

[0043] Furthermore, the inclined surface on the front side of the upright portion 10c1 of the inner cylinder 10 comes into contact with the inclined surface on the rear side of the base portion 2e1 of the rear barrel 2B, thereby forming a clip holding portion 18 that is erected laterally from the writing instrument body 7 by the first clip holding portion 2e of the rear barrel 2B and the second clip holding portion 10c of the inner cylinder 10. In addition, the first recess 10g of the inner cylinder 10 and the recess 2e3 of the rear barrel 2B are integrated to form a through hole 20. This through hole 20 has a larger diameter at one end than at the base end. The second end portion 8g is positioned within the through hole 20, and the bent portion 8h is positioned within the larger diameter relief portion of the through hole 20. As a result, the second end portion 8g of the clip member 8 is held within the through hole 20. In this way, the clip member 8 is fixed by the first end portion 8f being attached to the second recess 10h of the inner cylinder 10 and the second end portion 8g being attached to the through hole 20. In other words, the second recess 10h and the through hole 20 of the inner cylinder 10, which constitute the clip holding portion 18, function as mounting portions. The through hole 20 (mounting portion) formed in this manner is formed at the interface between the second clip holding portion 10c of the inner cylinder 10 and the first clip holding portion 2e of the rear shaft cylinder 2B.

[0044] Then, after attaching the inner cylinder 10 to the rear barrel 2B, the knock member 16 is inserted into the rear barrel 2B from the front, and then the rotor 12 is inserted into the rear barrel 2B from the front. Figures 12A to 12D show the state in which the inner cylinder with the clip member attached is attached to the rear barrel, and the knock member and rotor are attached in the writing instrument of the first embodiment of the present invention. Figure 12A is a cross-sectional view corresponding to Figure 4, Figure 12B is a cross-sectional view of BB in Figure 12A, Figure 12C is an enlarged cross-sectional view of part C in Figure 12B, and Figure 12D is a cross-sectional view of DD in Figure 12A. As shown in Figures 12A to 12D, since the elastic deformation portion 10e2 extends rearward from the base portion 10e1, the rotor 12 can be smoothly inserted when inserting the rotor 12, even if the elastic deformation portion 10e2 protrudes radially inward. Once the rotor 12 is inserted over the elastic deformation portion 10e2 and all the way to the rear, even if you try to move the rotor 12 forward, the rear edge of the elastic deformation portion 10e2 protrudes inward from the outer diameter of the rotor 12, so the outer peripheral edge of the front cam portion 12b of the rotor 12 comes into contact with the rear end face of the elastic deformation portion 10e2. For this reason, even if the writing instrument 1 is disassembled, such as when replacing the refill 4, the rotor 12 is held in place within the rear barrel 2B by the elastic deformation portion 10e2.

[0045] Next, a spring member 14 is placed at the tip of the front barrel 2A, and with the refill member 4 positioned so that its tip is inserted inside the spring member 14, the front barrel 2A and the rear barrel 2B are screwed together. As a result, the spring member 14 biases the refill member 4 backward, causing it to contact the front end surface of the rotor 12. Then, the knock member 16 is biased backward via the rotor 12, and the projection 16a of the knock member 16 contacts the front edge of the rear end 10b of the inner barrel 10. This completes the assembly of the writing instrument 1.

[0046] In the assembled state, when the rear end 8C of the clip member 8 is pushed radially inward toward the writing instrument body 7, the intermediate part 8B held by the second clip holding part 10c rotates around the pivot point, and the tip 8A of the clip member 8 moves radially outward so as to separate from the writing instrument body 7. Therefore, a user of the writing instrument 1 of this embodiment can open the clip member 8 and the writing instrument body 7 by pushing in the rear end 8C of the clip member 8 while gripping the barrel 2 of the writing instrument body 7 with the index, middle, ring, and little fingers of one hand, thereby separating the tip 8A of the clip member 8 from the writing instrument body 7.

[0047] In this invention, the rotation of the clip toward the writing instrument body includes not only cases where the clip rotates precisely around a single axis, but also cases where, as in the above embodiment, the tip of the clip member moves radially outward by pressing the rear of the clip member radially inward while the middle part of the clip is supported.

[0048] The writing instrument 1 of this embodiment provides the following effects. The writing instrument 1 of this embodiment comprises a cylindrical barrel 2, an inner cylinder 10 disposed inside the barrel 2, and a rotor 12 disposed inside the inner cylinder 10. The inner cylinder 10 has an elastically deformable portion 10e2 formed on the tip side of the rotor 12 when assembled, which protrudes inward beyond the outer diameter of the rotor 12 when placed inside the barrel 2. With this configuration, when the inner cylinder 10 is placed inside the barrel 2, the elastically deformable portion 10e2 protrudes inward beyond the outer diameter of the rotor 12. As a result, when replacing the refill member 4, the rotor 12 comes into contact with the elastically deformable portion 10e2, preventing the rotor 12 from detaching from the barrel 2.

[0049] Furthermore, in this embodiment, a reduced diameter portion 2c is formed on the inner circumferential surface of the shaft cylinder 2, and the elastically deformable portion 10e2 protrudes inward as its outer circumferential surface abuts against the reduced diameter portion 2c. With this configuration, the elastically deformable portion 10e2 can be made to protrude inward by arranging the inner cylinder 10 inside the shaft cylinder 2, and the rotor 12 can be prevented from detaching without complicating the structure of the inner cylinder 10.

[0050] Furthermore, in this embodiment, the inner cylinder 10 has a stepped portion on the periphery of the recess 10d on its outer surface. When the inner cylinder 10 is positioned inside the shaft cylinder 2, if an extraction force is applied to the inner cylinder 10, the stepped portion engages with the reduced diameter portion 2c, resisting the extraction force. With this configuration, the stepped portion engages with the reduced diameter portion 2c, allowing the inner cylinder 10 to be fixed to the shaft cylinder 2.

[0051] Furthermore, in this embodiment, the elastically deformable portion 10e2 has a cantilevered beam shape that extends toward the rear. With this configuration, the elastically deformable portion 10e2 can be configured to protrude inward when the inner cylinder is placed inside the shaft cylinder with a simple structure.

[0052] Furthermore, in this embodiment, the writing instrument 1 has a clip member 8 provided along the barrel 2, and a clip holding portion 18 is formed by the barrel 2 and the inner cylinder 10 to hold the clip member 8. With this configuration, the clip member 8 can be attached easily.

[0053] Furthermore, in this embodiment, the clip holding portion 18 has a through hole 20, the clip member 8 is made of wire, and the portion made of wire is placed and held within the through hole 20, and the through hole 20 is formed at the interface between the shaft cylinder 2 and the inner cylinder 10. With this configuration, since the clip member 8 is held by the through hole 20, it is possible to prevent the clip member 8 from easily coming off, and since the through hole 20 is located at the interface between the shaft cylinder 2 and the inner cylinder 10, the clip member 8 can be easily placed within the through hole 20.

[0054] In this embodiment, the application of the present invention to a retractable ballpoint pen has been described, but the writing instruments to which the present invention can be applied are not limited to this. For example, it can be applied to retractable mechanical pencils and writing instruments that do not have a retractable mechanism. It is also possible to attach a clip to the cap of a capped writing instrument. [Explanation of symbols]

[0055] 1 writing implements 2 shaft cylinder 2A front shaft cylinder 2A1 Screw 2B Rear shaft cylinder 2B1 Screw 2a Tip opening 2b Rear end opening 2c Reduced diameter part 2d Notch 2e First clip holding part 2e1 Base part 2e2 Engagement part 2e3 recess 4 Refill parts 4a Tip of the brush 6 Appearance mechanism 7. Writing instrument body 8. Clip component 8A tip 8B Middle part 8C Rear end 8a First arc-shaped portion 8b First vertical section 8c Second vertical section 8d Second arc-shaped part 8e Third vertical section 8f First end 8g Second end 8h bending part 10 Inner cylinder 10a Main body 10b Rear end 10b1 Extension 10c Second clip holding part 10c1 Standing part 10c2 Extension 10c3 Protrusion 10d recess 10e1 base 10e2 Elastic deformation part 10e3 convex part 10e4 Through hole 10f Cam section 10g First recess 10h Second recess 12 rotors 12a Proximal end 12b Cam section 14 Spring member 16 Knock Member 16a Protrusion 18 Clip holding part 20 through holes

Claims

1. A cylindrical shaft, An inner cylinder positioned inside the aforementioned shaft cylinder, A writing instrument comprising a rotor disposed inside the inner cylinder, The inner cylinder has an elastically deformable portion formed at a position closer to the tip of the rotor in the assembled state, which, when placed inside the shaft cylinder, protrudes inward beyond the outer diameter of the rotor. A reduced diameter portion is formed on the inner circumferential surface of the aforementioned shaft cylinder. The inner cylinder has a stepped portion on its outer surface. With the inner cylinder positioned inside the shaft cylinder, when an outward pulling force is applied to the inner cylinder, the stepped portion engages with the reduced diameter portion, resisting the outward pulling force. The outer circumferential surface of the elastically deformable portion comes into contact with the diameter reduction portion. A writing instrument characterized by the following features.

2. A cylindrical shaft, An inner cylinder positioned inside the aforementioned shaft cylinder, A writing instrument equipped with, It has a clip member provided along the shaft cylinder, The shaft cylinder and the inner cylinder form a clip holding portion for holding the clip member. The clip holding portion has a through hole, at least a part of the clip member is made of wire, and the portion made of wire is positioned and held within the through hole. By pressing the rear of the clip member radially inward, the tip of the clip member moves radially outward, A rotor is positioned inside the inner cylinder. The inner cylinder has an elastically deformable portion formed at a position closer to the tip of the rotor in the assembled state, which, when positioned inside the shaft cylinder, protrudes inward beyond the outer diameter of the rotor. A writing instrument characterized by the following features.

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