Knock-type writing implement

Abstract

To provide a knock type writing instrument of which a diameter can be reduced, and a length can be shortened.SOLUTION: A retractable mechanism 6 has: an inner cylinder 10 having a cam part extending along an inner surface of a barrel 2 in which a notch extending backward from a tip edge is formed; a rotor 12 which has a stem, a plurality of cam columns extending in an axial direction along the inner surface of the barrel 2 from the stem to a tip side, and an annular holding part which is connected to the tip side of the cam column, and holds a rear end part of a writing tool inside, and in which the stem is located in the inner cylinder; a spring 14 which energizes the rotor 12 to a rear end side; and a knock member 16 which is located in the inner cylinder 10, and can apply pressing force in a tip direction and a torque around an axis to the rotor 12. By switching between a state that the rotor 12 is rotated by the knock member 16 and cam column is accommodated in the notch and a state that the cam column is withdrawn from the notch, a brush tip of a refill member 4 held by the rotor 12 appears and disappears.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a knock-type writing instrument in which a writing member can be extended and retracted from the front end of a barrel by operating a retraction mechanism provided at the rear end of the barrel. [Background technology]

[0002] Conventionally, knock-type writing instruments have been known in which a refill is advanced or retracted by knocking an extension / retraction mechanism attached to the rear end of the barrel, thereby causing the tip of the refill to extend or retract from the tip of the barrel. For example, as described in Patent Document 1, the extension / retraction mechanism has an inner tube arranged in the barrel, a rotor arranged in the inner tube and holding the refill, a spring member that urges the rotor backward, and a knock member that presses the rotor.

[0003] A locking claw is formed on the outer surface of the rotor, and a claw-receiving portion is formed on the inner surface of the inner cylinder. When the knock member is pressed against the biasing force of the spring member, the rotor moves toward the tip and rotates. This allows the brush tip to protrude and retract from the tip of the barrel by switching between a state in which the locking claw of the rotor is locked to the claw-receiving portion on the inner cylinder surface and a state in which this lock is released. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-277980 Summary of the Invention [Problem to be solved by the invention]

[0005] In the knock-type writing instrument equipped with the above-described retractable mechanism, an inner tube is housed within a barrel, and a rotor is housed within the inner tube. To rotate the rotor, a pawl-receiving portion and a cam mechanism with a locking pawl are formed on the inner surface of the inner tube and the outer surface of the rotor, respectively. Furthermore, a refill is held inside the rotor. As a result, in addition to the thickness of the refill, the thickness of the rotor, the thickness of the cam mechanism, the thickness of the inner tube, and the thickness of the barrel must be ensured, resulting in a large diameter of the writing instrument. Alternatively, to reduce the diameter of the writing instrument, it is possible to not hold the refill inside the rotor, but to press the rear end of the refill with the tip of the rotor. However, in this case, the rear end of the refill is not inserted into the rotor, which increases the overall length of the writing instrument.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a knock-type writing implement that can be made smaller in diameter and length. [Means for solving the problem]

[0007] The knock-type writing instrument of the present invention is a knock-type writing instrument comprising a barrel having a front end opening and a rear end opening, a writing member housed in the barrel, and a retraction mechanism for causing the front end of the writing member to protrude and retract from the front end opening of the barrel. The retraction mechanism comprises an inner barrel attached to the rear end of the barrel and having a cam portion extending along the inner surface of the barrel, with a plurality of notches extending rearward from the front end edge, a base, a plurality of cam posts extending axially along the inner surface of the barrel from the base toward the front end, and a retainer connected to the front end of the cam posts and holding the rear end of the writing member inside. The writing implement has a ring-shaped holding portion having a base, a rotor with a base disposed within the inner cylinder, a spring that biases the rotor toward the rear end, and a knock member that is disposed within the inner cylinder and can be pressed toward the tip end to press the rotor toward the tip end. When the rotor is pressed forward by the knock member, it moves toward the tip end and rotates, switching between a brush tip storage state in which the cam post is housed in the notch and a brush tip advance state in which the cam post is released from the notch, thereby causing the brush tip of the writing element held by the rotor to appear and disappear.

[0008] According to the present invention having the above configuration, the inner tube is formed with a cam portion having a notch that fits along the inner surface of the barrel, and the rotor is formed with a cam pillar extending in the axial direction, so that it is not necessary to provide cams on the inner surface of the inner tube or the outer surface of the rotor, which allows the diameter of the knock-type writing instrument to be reduced.In addition, the annular holding portion of the rotor holds the rear end of the writing member inside the rotor, allowing the length of the writing instrument to be shortened.

[0009] In the present invention, preferably, the knock member has an internal space that is open at least to the front, and at least a portion of the base of the rotor is located within the internal space of the knock member, and the knock member holds the base of the rotor. According to the present invention having the above configuration, the knock member holds the base portion of the rotor, so that the knock member can be prevented from falling off.

[0010] In the present invention, the inner cylinder is preferably sandwiched between the knock member and the rotor, so that the inner cylinder, the knock member, and the rotor are assembled together. According to the present invention having the above configuration, the inner tube, knock member, and rotor of the retractable mechanism can be assembled together before assembly work can be performed, making assembly and refill replacement work easy.

[0011] In the present invention, preferably, the rotor is provided with a rotating side cam portion having an inclined portion, and a main body side cam portion having an inclined portion and movable relatively toward the rotating side cam portion, and when the rotor is pressed forward by the knock member, the inclined portion of the rotating side cam portion comes into contact with the inclined portion of the main body side cam portion and the rotating side cam portion moves toward the main body side cam portion, causing the rotor to rotate, and when the rotor is pushed back by the spring, the rotor is also rotated, thereby switching between a brush tip storage state and a brush tip forward state. According to the present invention having the above configuration, when the rotor is pressed forward by the knock member, the rotor can be rotated by the rotation-side cam portion and the main body-side cam portion.

[0012] In the present invention, preferably, the main body side cam portion or the rotation side cam portion further has a step portion. According to the present invention having the above configuration, the user can feel a knocking sensation when pressing the knock member.

[0013] In the present invention, preferably, the inner tube has a clip holding portion that protrudes laterally from the barrel and extends toward the tip along the barrel, the clip holding portion has a holding portion that protrudes from the surface and extends in the axial direction, the clip member has a notch that extends in the axial direction, and the clip member is held in the clip holding portion by the holding portion that protrudes from the surface fitting into the notch that extends in the axial direction.

[0014] According to the present invention having the above configuration, the clip member can be detachably attached to the writing instrument body by fitting the notched portion of the clip member into the holding portion formed in the clip holding portion of the inner tube.

[0015] In the present invention, it is preferable that a display portion is provided at a position that is visible from the outside other than the writing member, and a groove portion is formed in the display portion, and the display portion is formed by ink being drawn into and held in the groove portion by capillary action.

[0016] According to the present invention having the above configuration, the display unit is provided in a position visible from the outside, other than the ink storage unit, and therefore highly visible from the outside. Furthermore, since the display unit is formed by ink being drawn into and held in the groove by capillary action, the display unit can be formed without printing and can be formed during assembly. This facilitates inventory management and component switching during assembly.

[0017] In the present invention, preferably, a protrusion is formed on the inner peripheral surface of the inner cylinder, an axial groove is formed in the knock member extending in the axial direction from the front edge, and the protrusion is housed in the axial groove. According to the present invention having the above configuration, the knock member is movable in the axial direction relative to the inner cylinder, and rotation of the knock member relative to the inner cylinder can be restricted. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a knock-type writing instrument that can be made smaller in diameter and length. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view taken along an axial direction of a knock-type writing instrument according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the knock-type writing instrument shown in FIG. [Figure 3] 2 is a cross-sectional view taken along the axial direction of the barrel of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 4a] 2 is a perspective view showing the inner barrel of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 4b] 2 is a front view showing the inner barrel of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 4c] 2 is a cross-sectional view in the axial direction showing the inner barrel of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 4d] 2 is a bottom view showing the inner barrel of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 4e] 2 is a development view of a cam portion of an inner barrel of the knock-type writing instrument shown in FIG. 1. [Figure 5a] 2 is a perspective view showing a rotor of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 5b] 2 is a front view showing the rotor of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 5c] 2 is a development view of the annular portion of the rotor of the knock-type writing instrument shown in FIG. 1. [Figure 5d] 2 is a development view of the cam pillars and the holding portion of the rotor of the knock-type writing implement shown in FIG. 1. [Figure 6a] 2 is a perspective view showing a knock member of the knock-type writing implement shown in FIG. 1. FIG. [Figure 6b] 2 is a front view showing a knock member of the knock-type writing implement shown in FIG. 1. FIG. [Figure 6c] 2 is a cross-sectional view taken along the axial direction of the knock member of the knock-type writing implement shown in FIG. 1. FIG. [Figure 6d] 2 is a development view of the front part of the knock member of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 7a] 2 is a perspective view showing a clip member of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 7b] 2 is a front view showing a clip member of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 8a] 2 is a front view showing the retractable mechanism to which the clip member of the knock-type writing instrument shown in FIG. 1 is attached, with the tip of the refill member housed in the barrel. FIG. [Figure 8b] 2 is a cross-sectional view taken along the axial direction of the retractable mechanism to which the clip member of the knock-type writing instrument shown in FIG. 1 is attached, with the tip of the refill housed in the barrel. [Figure 9a] 2 is a front view showing the retractable mechanism to which the clip member of the knock-type writing instrument shown in FIG. 1 is attached, with the tip of the refill member protruding from the tip opening of the barrel. FIG. [Figure 9b] 2 is a cross-sectional view taken along the axial direction showing the protruding / retracting mechanism to which the clip member of the knock-type writing instrument shown in FIG. 1 is attached, with the tip of the refill member protruding from the distal end opening of the barrel. [Figure 10] 2 is a diagram (part 1) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 1. FIG. [Figure 11] 1. FIG. 4 is a diagram (part 2) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 12] 1. FIG. 4 is a diagram (part 3) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 13] 1. FIG. 4 is a diagram (part 4) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 14] 1. FIG. 5 is a diagram (part 5) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 15] 1. FIG. 6 is a diagram (part 6) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 16] 1. FIG. 14 is a diagram (part 7) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 17] 1. FIG. 8 is a diagram (part 8) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 18] 1. FIG. 9 is a diagram (part 9) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 19] FIG. 4 is a cross-sectional view taken along the axial direction of a knock-type writing instrument according to a second embodiment of the present invention. [Figure 20] FIG. 20 is an exploded perspective view of the knock-type writing instrument shown in FIG. 19. [Figure 21] 20 is a cross-sectional view taken along the axial direction of the barrel of the knock-type writing implement shown in FIG. 19. FIG. [Figure 22a] FIG. 20 is a perspective view showing the inner barrel of the knock-type writing instrument shown in FIG. [Figure 22b] 20 is a front view showing the inner barrel of the knock-type writing instrument shown in FIG. 19. [Figure 22c] 20 is an axial cross-sectional view showing the inner barrel of the knock-type writing instrument shown in FIG. 19. FIG. [Figure 22d] 20 is a bottom view showing the inner barrel of the knock-type writing instrument shown in FIG. 19. FIG. [Figure 22e] This is an enlarged view of part e in Figure 22c. [Figure 23a] FIG. 20 is a perspective view showing a rotor of the knock-type writing instrument shown in FIG. [Figure 23b] 20 is a front view showing the rotor of the knock-type writing instrument shown in FIG. 19. FIG. [Figure 24a] 20 is a perspective view showing a knock member of the knock-type writing implement shown in FIG. 19. FIG. [Figure 24b] 20 is a front view showing the knock member of the knock-type writing implement shown in FIG. 19. FIG. [Figure 24c] 20 is a cross-sectional view taken along the axial direction of the knock member of the knock-type writing implement shown in FIG. 19. FIG. [Figure 25a] 20 is a perspective view showing a clip member of the knock-type writing implement shown in FIG. 19. FIG. [Figure 25b] 20 is a front view showing a clip member of the knock-type writing implement shown in FIG. 19. FIG. [Figure 26a]20 is a front view showing the retractable mechanism to which the clip member of the knock-type writing instrument shown in FIG. 19 is attached, with the tip of the refill member housed in the barrel. FIG. [Figure 26b] 20 is a cross-sectional view taken along the axial direction showing the protruding mechanism to which the clip member of the knock-type writing instrument shown in FIG. 19 is attached, with the tip of the refill member housed in the barrel. FIG. [Figure 27a] 20 is a front view showing the retractable mechanism to which the clip member of the knock-type writing instrument shown in FIG. 19 is attached, with the tip of the refill member protruding from the tip opening. FIG. [Figure 27b] 20 is a cross-sectional view taken along the axial direction showing the protruding / retracting mechanism to which the clip member of the knock-type writing instrument shown in FIG. 19 is attached, with the tip of the refill member protruding from the tip opening. FIG. [Figure 28] FIG. 20 is a diagram (part 1) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 29] FIG. 20 is a diagram (part 2) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 30] FIG. 20 is a diagram (part 3) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 31] FIG. 20 is a diagram (part 4) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 32] FIG. 20 is a diagram (part 5) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 33] FIG. 20 is a diagram (part 6) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 34] FIG. 20 is a diagram (part 7) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 35] FIG. 20 is a diagram (part 8) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 36] FIG. 20 is a ninth diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 37]FIG. 20 is a diagram (part 10) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 38] FIG. 20 is an eleventh diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 39] FIG. 20 is a twelfth diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 40] FIG. 20 is a thirteenth diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 41] FIG. 20 is a fourteenth diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 19. [Figure 42] FIG. 10 is a cross-sectional view taken along the axial direction of a knock-type writing instrument according to a third embodiment of the present invention. [Figure 43] FIG. 10 is a cross-sectional view taken along the axial direction of a knock-type writing instrument according to a fourth embodiment of the present invention. [Figure 44] FIG. 44 is an exploded perspective view of the knock-type writing implement shown in FIG. 43. [Figure 45a] 44 is a cross-sectional view taken along the axial direction of the barrel of the knock-type writing implement shown in FIG. 43. FIG. [Figure 45b] FIG. 45B is an enlarged view of part b of FIG. 45A. [Figure 46a] FIG. 44 is a perspective view showing the inner barrel of the knock-type writing instrument shown in FIG. 43. [Figure 46b] FIG. 44 is a front view showing the inner barrel of the knock-type writing instrument shown in FIG. 43. [Figure 46c] 44 is an axial cross-sectional view showing the inner cylinder of the knock-type writing instrument shown in FIG. 43. [Figure 46d] 44 is a bottom view showing the inner barrel of the knock-type writing instrument shown in FIG. 43. FIG. [Figure 47a] FIG. 44 is a perspective view showing the rotor of the knock-type writing instrument shown in FIG. 43. [Figure 47b] FIG. 44 is a front view showing the rotor of the knock-type writing instrument shown in FIG. 43. [Figure 47c] FIG. 44 is a development view of the front part of the rotor of the knock-type writing instrument shown in FIG. 43. [Figure 48a]FIG. 44 is a perspective view showing a knock member of the knock-type writing implement shown in FIG. 43. [Figure 48b] 44 is a front view showing the knock member of the knock-type writing implement shown in FIG. 43. FIG. [Figure 48c] 44 is a cross-sectional view taken along the axial direction of the knock member of the knock-type writing implement shown in FIG. 43. FIG. [Figure 49a] FIG. 44 is a perspective view showing a clip member of the knock-type writing implement shown in FIG. 43. [Figure 49b] FIG. 44 is a front view showing the clip member of the knock-type writing implement shown in FIG. 43. [Figure 50] 44 is an enlarged cross-sectional view taken along the axial direction of the rear end portion of the clip member of the knock-type writing implement shown in FIG. 43. FIG. [Figure 51] 44 is a diagram (part 1) for explaining the operation of extending and retracting the writing tip of the knock-type writing implement shown in FIG. 43. FIG. [Figure 52] FIG. 44 is a diagram (part 2) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 53] FIG. 44 is a diagram (part 3) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 54] FIG. 44 is a diagram (part 4) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 55] FIG. 44 is a diagram (part 5) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 56] FIG. 44 is a diagram (part 6) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 57] FIG. 44 is a diagram (part 7) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 58] FIG. 44 is an eighth diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 59] FIG. 44 is a ninth diagram for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. [Figure 60] FIG. 44 is a diagram (part 10) for explaining the operation of extending and retracting the writing tip of the knock-type writing instrument shown in FIG. 43. [Figure 61] FIG. 10 is a perspective view showing a writing implement according to a fifth embodiment of the present invention. [Figure 62a] FIG. 62 is a side view of the writing instrument shown in FIG. 61. [Figure 62b] 62 is a cross-sectional view taken along the axial direction of the writing implement shown in FIG. 61. [Figure 63a] 62 is an axial cross-sectional view showing the barrel of the writing implement shown in FIG. 61. FIG. [Figure 63b] 62 is a perspective view of the rear end of the barrel of the writing implement shown in FIG. 61. FIG. [Figure 64a] FIG. 62 is a perspective view showing the inner barrel of the knock-type writing instrument shown in FIG. 61. [Figure 64b] FIG. 62 is a front view showing the inner barrel of the knock-type writing instrument shown in FIG. 61. [Figure 64c] 62 is a cross-sectional view taken along the axial direction of the inner cylinder of the knock-type writing instrument shown in FIG. 61. FIG. [Figure 64d] 62 is a bottom view showing the inner barrel of the knock-type writing instrument shown in FIG. 61. FIG. [Figure 65a] FIG. 62 is a perspective view showing the rotor of the knock-type writing implement shown in FIG. 61. [Figure 65b] FIG. 62 is a front view showing the rotor of the knock-type writing implement shown in FIG. 61. [Figure 66a] FIG. 62 is a perspective view showing a knock member of the knock-type writing implement shown in FIG. 61. [Figure 66b] 62 is a front view showing the knock member of the knock-type writing implement shown in FIG. 61. FIG. [Figure 66c] 62 is a cross-sectional view taken along the axial direction of the knock member of the knock-type writing implement shown in FIG. 61. FIG. [Figure 67a] FIG. 62 is a perspective view showing a clip member of the knock-type writing implement shown in FIG. 61. [Figure 67b] 62 is a front view showing the clip member of the knock-type writing implement shown in FIG. 61. FIG. [Figure 67c] 62 is a side view showing the clip member of the knock-type writing implement shown in FIG. 61. FIG. [Figure 68] FIG. 10 is an axial cross-sectional view showing a writing implement according to a sixth embodiment of the present invention. [Figure 69a]FIG. 69 is a perspective view showing the retraction mechanism of the knock-type writing implement shown in FIG. 68. [Figure 69b] FIG. 69 is a side view showing the retraction mechanism of the knock-type writing instrument shown in FIG. 68. [Figure 69c] FIG. 69 is a rear view showing the retraction mechanism of the knock-type writing implement shown in FIG. 68. [Figure 69d] FIG. 69 is a cross-sectional view showing the retraction mechanism of the knock-type writing implement shown in FIG. 68. [Figure 70a] FIG. 69 is a perspective view showing the inner barrel of the knock-type writing instrument shown in FIG. 68. [Figure 70b] FIG. 69 is a top view showing the inner barrel of the knock-type writing instrument shown in FIG. 68. [Figure 70c] FIG. 69 is a side view showing the inner barrel of the knock-type writing instrument shown in FIG. 68. [Figure 70d] 69 is a cross-sectional view taken along the axial direction of the inner cylinder of the knock-type writing instrument shown in FIG. 68. [Figure 71a] FIG. 69 is a perspective view showing the rotor of the knock-type writing instrument shown in FIG. 68. [Figure 71b] FIG. 69 is a front view showing the rotor of the knock-type writing instrument shown in FIG. 68. [Figure 71c] FIG. 69 is a top view showing the rotor of the knock-type writing instrument shown in FIG. 68. [Figure 71d] FIG. 69 is a cross-sectional view showing the rotor of the knock-type writing implement shown in FIG. 68. [Figure 72a] FIG. 69 is a perspective view showing a knock member of the knock-type writing implement shown in FIG. 68. [Figure 72b] FIG. 69 is a front view showing the knock member of the knock-type writing implement shown in FIG. 68. [Figure 72c] 69 is a cross-sectional view taken along the axial direction showing the knock member of the knock-type writing implement shown in FIG. 68. [Figure 73a] FIG. 69 is a perspective view showing the clip member of the knock-type writing implement shown in FIG. 68, as viewed from the radially outward direction. [Figure 73b] FIG. 69 is a perspective view showing the clip member of the knock-type writing implement shown in FIG. 68, as viewed from the inside in the radial direction. [Figure 73c] 69 is a side view showing the clip member of the knock-type writing implement shown in FIG. 68, viewed from the inside in the radial direction. FIG. [Figure 74] FIG. 69 is a perspective view showing the rear end of the knock-type writing implement shown in FIG. 68. DETAILED DESCRIPTION OF THE INVENTION

[0020] First Embodiment A first embodiment of a knock-type writing instrument of the present invention will be described in detail below with reference to the drawings. In the following description, the side from which the brush tip of the refill protrudes and retracts is referred to as the leading end side or front, and the side from which the knock portion of the retraction mechanism extends is referred to as the trailing end side or rear. Fig. 1 is a cross-sectional view taken along the axial direction of a knock-type writing instrument according to a first embodiment of the present invention. Fig. 2 is an exploded perspective view of the knock-type writing instrument shown in Fig. 1. As shown in Figs. 1 and 2, the knock-type writing instrument 1 of this embodiment comprises a cylindrical barrel 2, a refill member 4 housed in the barrel 2, a retractable mechanism 6 provided at the rear end of the barrel 2, and a clip member 8 connected to the retractable mechanism 6. The barrel 2, the refill member 4, and the retractable mechanism 6 form the writing instrument body.

[0021] Figure 3 is a cross-sectional view along the axial direction showing the barrel of the knock-type writing instrument shown in Figure 1. As shown in Figure 3, barrel 2 is formed in a cylindrical shape with a tapered tip. A tip opening 2a is formed at the tip of barrel 2, and a rear end opening 2b is formed at the rear end. A threaded portion 2c is formed on the inner surface of the rear end of barrel 2. A step 2d is formed in the middle of barrel 2, and the inner diameter of barrel 2 on the rear end side of step 2d is larger than the inner diameter on the tip side.

[0022] As shown in Figures 1 and 2, the refill member 4 includes an ink storage section 4a that stores ink, and a brush tip section 4b that is connected to the tip of the ink storage section 4a. The ink storage section 4a stores water-based or oil-based ink. The ink stored in the ink storage section 4a is supplied to the brush tip section 4b. The ink is transferred to the paper surface by contacting the transfer ball at the tip of the brush tip section 4b to the paper surface.

[0023] As shown in FIGS. 1 and 2, the retractable mechanism 6 includes an inner cylinder 10, a rotor 12, a spring member 14, and a knock member 16. 4a to 4e show the inner barrel of the knock-type writing instrument shown in Fig. 1, with Fig. 4a being a perspective view, Fig. 4b being a front view, Fig. 4c being an axial cross-sectional view, Fig. 4d being a bottom view, and Fig. 4e being an exploded view of the cam portion. As shown in Figs. 4a to 4e, inner barrel 10 comprises a cylindrical main body portion 10a, a cam portion 10b extending from main body portion 10a toward the front end, a rear end portion 10c connected to the rear end of main body portion 10a, and a clip holding portion 10d extending laterally from rear end portion 10c. Main body portion 10a, cam portion 10b, rear end portion 10c, and clip holding portion 10d are integrally molded.

[0024] The main body 10a is cylindrical, and the outer diameter of the main body 10a is approximately equal to the inner diameter of the barrel 2. A threaded portion 10e is formed on the outer peripheral surface of the main body 10a. Axial protrusions 10f extending in the axial direction are formed on the inner peripheral surface of the main body 10a at opposing positions spaced apart by 180 degrees.

[0025] The cam portion 10b is substantially cylindrical, and its inner and outer diameters are equal to those of the main body portion 10a. As shown in FIG. 4e, the cam portion 10b has first notches 18 and second notches 20 formed alternately in the circumferential direction. The first notches 18 have axial grooves 18a extending axially rearward from the leading edge and guide portions 18b formed contiguous with the axial grooves 18a in a clockwise direction (to the right in FIG. 4e). The axial grooves 18a are grooves that extend axially with a constant circumferential width and extend further rearward than the second notches 20. The guide portions 18b are formed in a triangular shape such that the cutting depth (distance from the leading edge of the inner cylinder) decreases clockwise when viewed from the circumferential surface. The second notches 20 are formed in a triangular shape such that the cutting depth decreases clockwise when viewed from the circumferential surface. The maximum cutting depth of the second cutout portion 20 is smaller than the cutting depth of the axial groove portion 18a of the first cutout portion 18 and larger than the maximum cutting depth of the guide portion 18b. The position of the counterclockwise end (left direction in FIG. 4e) of the second cutout portion 20 coincides with the position of the clockwise end of the guide portion 18b of the adjacent first cutout portion 18. In addition, the position of the clockwise end of the second cutout portion 20 coincides with the position of the counterclockwise end of the axial groove portion 18a of the adjacent first cutout portion 18. The rear end portion 10c is formed in a cylindrical shape with an outer diameter slightly smaller than that of the barrel 2.

[0026] Clip holding portion 10d has a connecting portion 10d1 extending radially outward and forward from rear end portion 10c, a main body portion 10d2 extending forward from the front end of connecting portion 10d1, and holding portion 10d3 formed on the radially inner surface of main body portion 10d2. Holding portion 10d3 extends forward from connecting portion 10d1 and has a T-shaped cross section along its entire length perpendicular to the axial direction.

[0027] Figures 5a to 5d show the rotor of the knock-type writing instrument shown in Figure 1, with Figure 5a being a perspective view, Figure 5b being a front view, Figure 5c being an expanded view of the annular portion, and Figure 5d being an expanded view of the cam posts and holder. As shown in Figures 5a to 5d, rotor 12 has a cylindrical base 21, four cam posts 28 extending forward from base 21, and holders 30 connected to the front ends of cam posts 28. The base 21 has a cylindrical main body 22 , a rear end 24 connected to the rear end of the main body 22 , and an annular ring 26 connected to the front end of the main body 22 .

[0028] The main body 22 is formed in a cylindrical shape, and its outer diameter is slightly smaller than the inner diameter of the front portion of the knock member 16, which will be described later. The rear end of the main body 22 has a tapered portion 22a whose diameter tapers rearward.

[0029] The rear end portion 24 has a cylindrical portion 24a that is continuous with the rear end of the main body portion 22, a truncated cone-shaped (frustum-shaped) truncated cone portion 24b that is continuous with the rear end of the cylindrical portion 24a, and an indicator portion 24c that is continuous with the rear end of the truncated cone portion 24b. The cylindrical portion 24a has a circular cross-sectional shape that is constant in the axial direction. The outer diameter of the cylindrical portion 24a is slightly smaller than the inner diameter of the rear portion 36 (FIG. 6) of the knock member 16. The truncated cone portion 24b has a truncated cone shape with a larger diameter at the tip end. The diameter of the rear end of the truncated cone portion 24b is approximately equal to the diameters of the cylindrical portion 24a and the indicator portion 24c. The indicator portion 24c is a cylindrical portion that extends rearward from the rear end of the truncated cone portion 24b. The indicator portion 24c has multiple grooves that extend in the axial direction.

[0030] The annular portion 26 is connected to the front end of the main body portion 22 and is formed in an annular shape. The outer diameter of the annular portion 26 is larger than the outer diameter of the main body portion 22 and smaller than the outer diameter of the holding portion 30. A rotation-side cam portion 26b is formed on the rear surface of the annular portion 26. The rotation-side cam portion 26b includes four cam protrusions 26a formed at 90-degree intervals in the circumferential direction. The cam protrusions 26a are in the shape of an isosceles triangle that protrudes rearward.

[0031] The cam pillars 28 have an arc-shaped cross section perpendicular to the axial direction, are connected to the radially outer peripheral surface of the annular portion 26 of the base 21, and extend forward. The cam pillars 28 are attached at 90-degree intervals in the circumferential direction. The cam pillars 28 have a circumferential width that is half that of the cam projections 26a formed on the annular portion 26. Each cam pillar 28 is connected to the outer surface of the right half of the cam projections 26a of the annular portion 26 in FIGS. 5(b) to 5(d). The rear end surface of the cam pillar 28 is flush with the rear end surface of the clockwise rear half of the cam projections 26a of the annular portion 26. In other words, the rear end surface 28a of the cam pillar 28 is formed as an inclined portion so that the height of the projection toward the rear decreases in the clockwise direction.

[0032] The holding portion 30 is formed in an annular shape. The inner and outer diameters of the holding portion 30 are equal to the inner and outer diameters of the cam pillar 28. The spring member 14 is a spring member made of a spiral metal member.

[0033] Figures 6a to 6c show the knock member of the knock-type writing instrument shown in Figure 1, with Figure 6a being a perspective view, Figure 6b being a front view, Figure 6c being a cross-sectional view along the axial direction, and Figure 6d being a developed view of the front portion. The knock member 16 has a front portion 32, a middle portion 34 that is continuous with the rear of the front portion, and a rear portion 36 that is continuous with the rear of the middle portion 34. The front portion 32 has a cylindrical internal space that is open at least forward and is formed by a pair of arc-shaped cross-sectional walls. The outer diameter of the front portion 32 is slightly smaller than the inner diameter of the main body portion 10a of the inner cylinder 10. The inner diameter of the front portion 32 is slightly larger than the outer diameter of the main body portion 22 of the rotor 12. A pair of axial grooves 32a, which extend axially, open forward, and extend a predetermined length rearward, are formed in the front portion 32 at 180-degree intervals in the circumferential direction. A main body cam portion 32b is formed on the end face of the front end of the front portion 32. The main body cam portion 32b includes three triangular protrusions 32b1, 32b2, and 32b3, which are formed between the pair of axial grooves 32a and aligned in the circumferential direction. As described below, the main body cam portion 32b of the knock member 16 and the rotation-side cam portion 26b of the rotor 12 rotate the rotor 12 by a predetermined angle when the knock member 16 is pressed.

[0034] The intermediate portion 34 is formed in an annular shape, and a locking portion 34b is formed on the inner surface thereof so as to protrude in an annular shape. The front portion of the locking portion 34b is preferably formed with an inclined portion whose diameter decreases toward the rear, as shown in Figure 6(c). The rear portion 36 is formed in a cylindrical shape, and the opposing portions of the outer circumferential surface are formed flat.

[0035] FIG. 7 shows the clip member of the knock-type writing instrument shown in FIG. 1, with (a) being a perspective view and (b) being a front view. As shown in FIG. 7, clip member 8 includes a connecting portion 8a and a main body portion 8b extending axially forward from connecting portion 8a. A notch 8c extending axially is formed in connecting portion 8a. Furthermore, protrusions 8d protruding toward the center of notch 8c are formed on both radially outer edges of notch 8c. As shown in FIG. 1, retaining portion 10d3 of inner tube 10 is accommodated in notch 8c of clip member 8, thereby fixing clip member 8 to inner tube 10 so as to be positioned to the side of barrel 2.

[0036] Figures 8 and 9 are diagrams showing the retractable mechanism to which the clip member of the knock-type writing instrument shown in Figure 1 is attached, with (a) being a front view and (b) being a cross-sectional view along the axial direction. Note that Figure 8 shows a state in which the tip of the refill member 4 is housed in the barrel 2, and Figure 9 shows a state in which the tip of the refill member 4 protrudes from the tip opening 2a of the barrel 2. Also, the spring member of the retractable mechanism is not shown in Figures 8 and 9.

[0037] 8 and 9, the knock member 16 is inserted into the inner cylinder 10 from the rear so that the axial protrusion 10f (FIG. 4c) of the inner cylinder 10 is positioned in the axial groove 32a of the knock member 16. The rotor 12 is inserted into the knock member 16 from the front to a position where the truncated cone portion 24b formed on the base 21 exceeds the locking portion 34b of the knock member 16. The cam portion 10b of the inner cylinder 10 and the cam post 28 of the rotor 12 are aligned along the inner surface of the barrel 2 and are positioned on the same circle.

[0038] With this configuration, the knock member 16 is restricted from rotating with respect to the inner cylinder 10, but is movable in the axial direction relative to the inner cylinder 10. Furthermore, the rotor 12 is rotatable with respect to the knock member 16, and is also movable in the axial direction relative to the inner cylinder 10 between a position where the locking portion 34b of the knock member 16 abuts against the truncated cone portion 24b of the rotor 12 and a position where the protrusions 32b1, 32b2, 32b3 of the knock member 16 abut against the cam protrusion 26a of the rotor 12. In other words, the base 21 of the rotor 12 is held by the knock member 16, and the rotation-side cam portion 26b can move relative to the main body-side cam portion 32b.

[0039] The main body portion 10a and cam portion 10b of the inner tube 10 are accommodated in the rear end opening 2b of the barrel 2, and the threaded portion 2c of the barrel 2 and the threaded portion 10e of the inner tube 10 are threadedly engaged with each other, thereby attaching the inner tube 10 to the rear end of the barrel 2.

[0040] The rear end of the refill member 4 is inserted into the annular holding portion 30 of the rotor 12 and abuts against the front surface of the annular portion 26. This allows the refill member 4 to be held by the rotor 12 so that it can be fed out and pulled back.

[0041] The spring member 14 is disposed between the refill member 4 and the barrel 2. In a contracted state, the spring member 14 is sandwiched between the step 2d of the barrel 2 and the holding portion 30 of the rotor 12. As a result, the rotor 12 is biased rearward by the spring member 14.

[0042] Next, the operation of extending and retracting the writing tip of the knock-type writing instrument of this embodiment will be described. Figures 10 to 18 are diagrams for explaining the operation of extending and retracting the writing tip using the knock-type writing instrument shown in Figure 1. Figures 10 to 18 show an expanded view of the cam portion 10b of the inner barrel 10, the annular portion 26 and cam pillar 28 of the rotor 12, and the front portion 32 of the knock member 16. In Figures 10 to 18, the cam portion 10b of the inner barrel 10 and the cam pillar 28 of the rotor 12 are shown by solid lines, and the annular portion 26 of the rotor 12 and the front portion 32 of the knock member 16 are shown by dashed lines.

[0043] 10 shows a state (tip-retained state) in which the tip 4b of the refill member 4 of the knock-type writing instrument is housed in the barrel 2. As shown in FIG. 10, the rotor 12 is urged rearward by the spring member 14, causing the cam pillar 28 of the rotor 12 to enter the first notch 18 of the inner barrel 10, and the rear end of the cam pillar 28 abuts against the bottom of the first notch 18.

[0044] First, in order to advance the brush tip portion 4b of the refill member 4 from the state shown in Fig. 10, the knock member 16 is pushed forward. When the knock member 16 is pushed forward, first, as shown in Fig. 11, the edge of the left half in the figure of the central protrusion 32b2 of the three consecutive protrusions of the knock member 16 abuts against the edge of the right half of the cam protrusion 26a of the annular portion 26 of the rotor 12. When the knock member 16 is pushed forward further in this abutting state, the cam pillar 28 of the rotor 12 enters the first notch 18 of the inner cylinder 10, and the rotor 12 is pushed forward (downward in the figure) without rotating.

[0045] Further, when the knock member 16 is pushed forward, the cam post 28 of the rotor 12 disengages from the first notch 18 of the inner cylinder 10, as shown in FIG. 12 . When the cam post 28 of the rotor 12 disengages from the first notch 18 of the inner cylinder 10 in this manner, the inclined portion of the left half of the central protrusion 32b2 of the knock member 16 abuts against the inclined portion of the right half of the cam protrusion 26a of the annular portion 26 of the rotor 12. Because the rotor 12 is biased rearward by the spring member 14, the inclined portion of the right half of the cam protrusion 26a of the annular portion 26 of the rotor 12 moves along the inclined portion of the left half of the central protrusion 32b2 of the knock member 16. As a result, the rotor 12 rotates leftward in the drawing and moves rearward. At this time, the rotor 12 moves rearward, allowing the user to feel a knock (a change in the biasing force on the knock member 16). 13, the cam protrusion 26a of the annular portion 26 of the rotor 12 fits into the groove between the left protrusion 32b1 and the central protrusion 32b2 of the knock member 16. That is, the edge of the left half of the cam protrusion 26a of the annular portion 26 of the rotor 12 abuts against the edge of the right half of the left protrusion 32b1 of the knock member 16, and the edge of the right half of the cam protrusion 26a of the annular portion 26 of the rotor 12 abuts against the edge of the left half of the central protrusion 32b2 of the knock member 16.

[0046] When the user feels a knock, he or she releases the pushing force of the knock member 16. When the pushing force of the knock member 16 is released in this manner, the rotor 12, which is biased rearward by the spring member 14, moves rearward, and the rear end surface 28a of the cam post 28 of the rotor 12 comes into contact with the inclined portion 20a of the second notch 20 of the inner cylinder 10. Then, because the rotor 12 is biased rearward by the spring member 14, the rotor 12 rotates leftward in the figure and moves rearward. The knock member 16 also moves rearward together with the rotor 12. As a result, the end of the cam post 28 of the rotor 12 fits into the deepest portion of the second notch 20 of the inner cylinder 10, as shown in FIG. 14 . That is, the rear end surface 28a of the cam pillar 28 of the rotor 12 abuts against the inclined portion 20a of the second cutout portion 20 of the inner cylinder 10, and the left edge 28b of the cam pillar 28 of the rotor 12 abuts against the edge portion 20b extending in the axial direction of the second cutout portion 20 of the inner cylinder 10. This causes the brush tip portion 4b of the refill member 4 to be held in a state in which it protrudes from the tip opening 2a of the barrel 2 (brush tip-extending state).

[0047] Next, to retract the brush tip portion 4b of the refill member 4, the knock member 16 is pushed forward. At this time, the left edge 28b of the cam post 28 of the rotor 12 abuts against the axially extending edge 20b of the second cutout portion 20 of the inner cylinder 10, and the edge of the right half of the cam protrusion 26a of the annular portion 26 of the rotor 12 abuts against the edge of the left half of the left protrusion 32b1 or the right protrusion 32b3 of the knock member 16. Therefore, the rotor 12 moves forward without rotating. Then, as shown in FIG. 15, the cam post 28 of the rotor 12 disengages from the second cutout portion 20 of the inner cylinder 10.

[0048] When the cam pillar 28 of the rotor 12 is released from the second notch 20 of the inner cylinder 10, the rotor 12 is urged rearward by the spring member 14, and the edge of the right half of the cam protrusion 26a of the annular portion 26 of the rotor 12 abuts against the edge of the left half of the left protrusion 32b1 or the right protrusion 32b3 of the knock member 16, causing the rotor 12 to rotate leftward and move rearward in the figure. As a result, as shown in FIG. 16 , the cam protrusion 26a of the annular portion 26 of the rotor 12 enters between the central protrusion 32b2 and the right protrusion 32b3 of the knock member 16. At this time, the rotor 12 moves rearward, allowing the user to feel a knock (a change in the urging force on the knock member 16).

[0049] When the user feels a knock, he or she releases the pushing force of the knock member 16. When the pushing force of the knock member 16 is released, the rotor 12 moves rearward due to the biasing force of the spring member 14, and the rear end surface 28a of the cam post 28 of the rotor 12 abuts against the edge of the guide portion 18b of the inner cylinder 10, as shown in FIG. 17. Furthermore, as the biasing force of the spring member 14 acts on the rotor 12, the rotor 12 moves rearward with the rear end surface 28a of the cam post 28 of the rotor 12 abutting against the edge of the guide portion 18b of the inner cylinder 10, causing the rotor 12 to rotate leftward in the figure. Then, as shown in FIG. 18, the cam post 28 of the rotor 12 enters the first notch 18 of the inner cylinder 10, and the rear end of the cam post 28 of the rotor 12 abuts against the deepest part of the first notch 18 of the inner cylinder 10. As a result, the brush tip portion 4b of the refill member 4 of the knock-type writing instrument is accommodated in the barrel 2 (brush tip accommodated state).

[0050] As described above, the present embodiment provides the following advantageous effects. According to this embodiment, the inner tube 10 is formed with a cam portion 10b having a first notch 18 that fits along the inner surface of the barrel 2, and the rotor 12 is formed with a cam pillar 28 that extends in the axial direction, so that there is no need to provide cams on the inner surface of the inner tube 10 or the outer surface of the rotor 12, which allows the diameter of the knock-type writing instrument to be reduced. Also, the annular holding portion 30 of the rotor 12 holds the rear end of the refill member 4 inside the rotor 12, allowing the length of the writing instrument to be reduced.

[0051] In this embodiment, the knock member 16 has an internal space that is open to the front, and the rear end 24 of the rotor 12 is located within the internal space of the knock member 16, and the knock member 16 holds the rear end 24 of the rotor 12. In this way, the knock member 16 holds the base of the rotor 12, preventing the knock member 16 from falling off.

[0052] In addition, in this embodiment, the inner cylinder 10, the knock member 16, and the rotor 12 are assembled together by sandwiching the inner cylinder 10 between the knock member 16 and the rotor 12. This allows the assembly work to be performed after the inner cylinder 10, the knock member 16, and the rotor 12 of the protruding / retracting mechanism 6 are assembled together, making assembly and refill replacement easy.

[0053] Furthermore, in this embodiment, the rotor 12 is provided with a rotation-side cam portion 26b having an inclined portion of the knock member 16, and a body-side cam portion 32b having an inclined portion and movable relatively toward the rotation-side cam portion 26b, and when the rotor 12 is pressed forward by the knock member 16, the inclined portion of the rotation-side cam portion 26b contacts the inclined portion of the body-side cam portion 32b, causing the rotation-side cam portion 26b to move toward the body-side cam portion 32b, thereby rotating the rotor 12, and further, when the rotor 12 is pushed back rearward by the spring member 14, the rotor 12 is rotated, thereby switching between the brush tip retracted state and the brush tip advanced state. According to this embodiment, when the rotor 12 is pressed forward by the knock member 16, the rotor 12 can be rotated by the rotation-side cam portion 26b and the body-side cam portion 32b.

[0054] In addition, in this embodiment, an axial protrusion 10f is formed on the inner peripheral surface of the inner cylinder 10, an axial groove 32a is formed in the knock member 16 extending axially from the front edge, and the axial protrusion 10f is accommodated in the axial groove 32a. As a result, the knock member 16 is movable in the axial direction relative to the inner cylinder 10, but is restricted from rotating.

[0055] Second Embodiment A second embodiment of the present invention will be described below with reference to the drawings. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted. Fig. 19 is a cross-sectional view along the axial direction showing a knock-type writing instrument according to a second embodiment of the present invention. Fig. 20 is an exploded perspective view of the knock-type writing instrument shown in Fig. 19. As shown in Figs. 19 and 20, a knock-type writing instrument 101 of this embodiment includes a cylindrical barrel 102, a refill member 4 housed in the barrel 102, a retractable mechanism 106 provided at the rear end of the barrel 102, and a clip member 108 connected to the retractable mechanism 106. The barrel 102, the refill member 4, and the retractable mechanism 106 form the writing instrument body.

[0056] Figure 21 is a cross-sectional view along the axial direction showing the barrel of the knock-type writing instrument shown in Figure 19. As shown in Figure 21, barrel 102 is formed in a cylindrical shape with a tapered tip. A tip opening 102a is formed at the tip of barrel 102, and a rear end opening 102b is formed at the rear end. A screw portion 102c is formed on the inner surface of the rear end of barrel 102.

[0057] As shown in FIGS. 19 and 20, the retractable mechanism 106 includes an inner cylinder 110, a rotor 112, a spring member 114, and a knock member 116. Figures 22a to 22e show the inner barrel of the knock-type writing instrument shown in Figure 19, with Figure 22a being a perspective view, Figure 22b being a front view, Figure 22c being an axial cross-sectional view, Figure 22d being a bottom view, and Figure 22e being an enlarged view of part e in Figure 22c. As shown in Figures 22a to 22e, inner barrel 110 comprises a cylindrical main body portion 110a, a cam portion 110b extending from main body portion 110a toward the tip, and a rear end portion 110c connected to the rear end of main body portion 110a. Main body portion 110a, cam portion 110b, and rear end portion 110c are integrally molded.

[0058] The main body 110a is cylindrical, and the outer diameter of the main body 110a is approximately equal to the inner diameter of the barrel 102. A threaded portion 110e is formed on the outer peripheral surface of the main body 110a. A reduced diameter portion 110g is provided at the front end of the main body 110a so that the inner diameter is reduced, and a main body cam portion 110f is formed on the inner peripheral surface of the reduced diameter portion 110g. A pair of notches 110g1 are formed in the reduced diameter portion 110g, spaced 180° apart in the circumferential direction. These notches 110g1 are provided to prevent interference between the rotation-side cam portion 122b of the rotor 112 and the reduced diameter portion 110g during assembly.

[0059] As shown in Fig. 22e, the main body side cam portion 110f has a plurality of cam protrusions 110f5 arranged in the circumferential direction. In this embodiment, two cam protrusions 110f5 are arranged consecutively in a predetermined circumferential direction (leftward in Fig. 22e) from the cutout portion 110g1, and a flat portion 110f4 is arranged consecutively to this cam protrusion 110f5, and two more cam protrusions 110f5 are arranged consecutively to the flat portion 110f4.

[0060] Each cam protrusion 110f5 has a side surface 110f0, a rear inclined portion 110f1, a front inclined portion 110f3, and a step portion 110f2 connecting the rear inclined portion 110f1 and the front inclined portion 110f3. The side surface 110f0 extends in the axial direction and is continuous with the rear end of the rear inclined portion 110f1. The rear inclined portion 110f1 faces rearward and is inclined forward in a predetermined direction. The step portion 110f2 extends forward in the axial direction from the end of the rear inclined portion 110f1 and is connected to the end of the front inclined portion 110f3. The front inclined portion 110f3 is inclined forward in a predetermined direction.

[0061] The cam portion 110b is substantially cylindrical, and its inner and outer diameters are equal to those of the main body portion 110a. As shown in Figures 22b and 22c, the cam portion 110b has first notches 118 and second notches 120 formed alternately in the circumferential direction. The configuration of the cam portion 110b of the second embodiment is the same as the configuration of the cam portion 110b of the first embodiment, and includes the first notches 118 and the second notches 120, with the first notches 118 having an axial groove 118a and a guide portion 118b, and the second notches 120 having an edge portion 120b and an inclined portion 120a.

[0062] The rear end portion 110c includes a front large diameter portion 110c1 whose outer diameter is slightly larger than the inner diameter of the barrel 102, an intermediate small diameter portion 110c2 that continues rearward from the front large diameter portion 110c1, and a rear large diameter portion 110c3 that continues rearward from the intermediate small diameter portion 110c2 and has a larger diameter than the intermediate small diameter portion 110c2. The front large diameter portion 110c1 has a diameter slightly larger than the intermediate small diameter portion 110c2, and the rear large diameter portion 110c3 has a diameter larger than the intermediate small diameter portion 110c2. In addition, the rear end portion 110c is formed with cutouts 110c4 that extend in the axial direction across the front large diameter portion 110c1 and the intermediate small diameter portion 110c2 at intervals of 180° in the circumferential direction.

[0063] Figures 23a and 23b show the rotor of the knock-type writing instrument shown in Figure 19, with Figure 23a being a perspective view and Figure 23b being a front view. As shown in Figures 23a and 23b, rotor 112 has a cylindrical base 121, four cam pillars 128 extending forward from base 121, and holding portions 130 connected to the front ends of the cam pillars 128. The base 121 has a cylindrical main body 122 , a rear end 124 connected to the rear end of the main body 122 , and an annular ring 126 connected to the front end of the main body 122 .

[0064] The main body 122 is formed in a cylindrical shape, and a rotation-side cam portion 122b is formed at the rear end of the main body 122 at a predetermined angle (180° in this embodiment). The rotation-side cam portion 122b protrudes radially outward from the outer surface of the main body 122 and has an inclined portion 122b1 at its front end. The inclined portion 122b1 is inclined rearward in a predetermined direction.

[0065] The rear end portion 124 has an annular recess 124a that continues to the rear end of the main body portion 122, a truncated conical portion 124b that is shaped like a truncated cone and continues to the rear end of the annular recess 124a, and a cylindrical portion 124c that continues to the rear end of the truncated cone portion 124b. The annular recess 124a has a circular cross-sectional shape that is constant in the axial direction, and the diameter of the annular recess 124a is smaller than the diameter of the main body portion 122. The truncated conical portion 124b has a truncated conical shape with a larger diameter at the tip end. The diameter of the tip of the truncated cone portion 124b is larger than the diameter of the annular recess 124a, and the diameter of the rear end is equal to the diameter of the cylindrical portion 124c.

[0066] The annular portion 126 is connected to the front end of the main body portion 122 and has an annular shape. The outer diameter of the annular portion 126 is larger than the outer diameter of the main body portion 122 and smaller than the outer diameter of the holding portion 130.

[0067] The configurations of the cam pillar 128 and the holding portion 130 in the second embodiment are substantially the same as the configurations of the cam pillar 28 and the holding portion 30 in the first embodiment. The spring member 114 is a spring member made of a spiral metal member.

[0068] 24a to 24c show the knock member of the knock-type writing instrument shown in FIG. 19, with FIG. 24a being a perspective view, FIG. 24b being a front view, and FIG. 24c being a cross-sectional view along the axial direction. Knock member 116 has a front portion 132 and a rear portion 136 that continues to the rear of the front portion and has a larger outer diameter than front portion 132. The outer diameters of front portion 132 and rear portion 136 are slightly smaller than the inner diameter of main body portion 110a of inner tube 110. Knock member 116 is formed with a through-hole 116a that penetrates in the axial direction. Furthermore, an annular locking portion 116b that protrudes radially inward is formed at the tip of through-hole 116a.

[0069] 25a and 25b show the clip member of the knock-type writing instrument shown in FIG. 19, with FIG. 25a being a perspective view and FIG. 25b being a front view. As shown in FIGS. 25a and 25b, clip member 108 includes connecting portion 108a and main body portion 108b extending axially forward from connecting portion 108a. Connecting portion 108a is formed in an annular shape. At the axial middle of the inner circumferential surface of connecting portion 108a, intermediate protrusions 108a1 are formed, protruding radially inward along the entire circumference. Furthermore, axial protrusions 108a2 are formed on the inner circumferential surface of connecting portion 108a, extending from the front end to the rear end of intermediate protrusion 108a1, at 180° intervals in the circumferential direction.

[0070] As shown in Figures 19 and 20, the clip member 108 is fixed to the inner tube 110 so as to be positioned to the side of the barrel 102 by inserting the inner tube 110 inward from the rear end side of the connecting portion 108a, fitting the axial convex portion 108a2 into the cutout portion 110c4 of the inner tube 110, and fitting the intermediate convex portion 108a1 between the front large diameter portion 110c1 and the rear large diameter portion 110c3 of the inner tube 110.

[0071] Figures 26a, 26b, 27a, and 27b are diagrams showing the retractable mechanism to which the clip member of the knock-type writing instrument shown in Figure 19 is attached, with Figures 26a and 27a being front views and Figures 26b and 27b being cross-sectional views along the axial direction. Figures 26a and 26b show a state in which the tip of the refill member 4 is housed in the barrel 102, and Figures 27a and 27b show a state in which the tip of the refill member 4 protrudes from the tip opening 102a of the barrel 102.

[0072] As shown in Figures 26a, 26b, 27a, and 27b, a clip member 108 is attached to the rear end 110c of the inner cylinder 110. A main body 122 and a rear end 124 of the rotor 112 are inserted into the through hole of the inner cylinder 110 from the front end side. A spring member 114 is inserted into the through hole of the inner cylinder 110 from the rear end side, and a knock member 116 is inserted from behind the spring member 114. The rear end 124 of the rotor 112 fits into the through hole of the knock member 116 from the front.

[0073] The rotor 112 is inserted from the front into the knock member 116 to a position where the truncated cone portion 124b formed on the base portion 121 exceeds the locking portion 116b of the knock member 116. The cam portion 110b of the inner cylinder 110 and the cam pillar 128 of the rotor 112 are aligned along the inner surface of the shaft cylinder 102 and are positioned on the same circle. Furthermore, the main body side cam portion 110f of the inner cylinder 110 and the rotation side cam portion 122b of the rotor 112 are positioned on the same circle. The spring member 114 has a front end that abuts against the reduced diameter portion 110 g of the inner cylinder 110 , and a rear end that abuts against the front end of the rear portion 136 of the knock member 116 .

[0074] With this configuration, the locking portion 116b of the knock member 116 fits into the annular recess 124a of the rotor 112, and the front and rear are sandwiched between the main body portion 122 and the truncated cone portion 124b of the rotor 112, thereby restricting relative axial movement between the knock member 116 and the rotor 112. Furthermore, the knock member 116 and the rotor 112 are movable in the axial direction relative to the inner cylinder 110, and the knock member 116 is urged rearward by the spring member 114. In other words, the base portion 121 of the rotor 112 is held by the knock member 116, and the rotation-side cam portion 122b is movable relative to the main body-side cam portion 110f.

[0075] The main body portion 110a and cam portion 110b of the inner tube 110 are accommodated in the rear end opening 102b of the barrel 102, and the threaded portion 102c of the barrel 102 and the threaded portion 110e of the inner tube 110 are threadedly engaged with each other, thereby attaching the inner tube 110 to the rear end of the barrel 102.

[0076] The rear end of the refill member 4 is inserted into the annular holding portion 130 of the rotor 112 and abuts against the front surface of the annular portion 126. This allows the refill member 4 to be held by the rotor 112 so that it can be fed out and pulled back.

[0077] Next, the operation of extending and retracting the writing tip of the knock-type writing instrument of this embodiment will be described. Figures 28 to 41 are diagrams for explaining the extension and retraction operation of the writing tip using the knock-type writing instrument shown in Figure 19. Figures 28 to 41 show an expanded view of the rotation-side cam portion 122b and cam pillar 128 of the rotor 112, and the cam portion 110b and main body-side cam portion 110f of the inner cylinder 110. In Figures 28 to 41, the rotation-side cam portion 122b and cam pillar 128 of the rotor 112 are shown by solid lines, and the cam portion 110b and main body-side cam portion 110f of the inner cylinder 110 are shown by dashed lines.

[0078] Figure 28 shows a state (tip-stored state) in which the tip 4b of the refill member 4 of the knock-type writing instrument is stored in the barrel 102. As shown in Figure 28, the knock member 116 is urged rearward by the spring member 114, which urges the rotor 112 rearward together with the knock member 116, causing the cam pillar 128 of the rotor 112 to enter the first notch 118 of the inner cylinder 110, and the rear end of the cam pillar 128 to abut against the bottom of the first notch 118.

[0079] First, in order to advance the brush tip portion 4b of the refill member 4 from the state shown in FIG. 28, the knock member 116 is pushed forward. As shown in FIG. 29, when the knock member 116 is pushed forward, the rotor 112 advances forward in conjunction with this. Then, as shown in FIG. 29, the cam pillar 128 disengages from the first notch portion 118 of the inner tube 110. Immediately after the cam pillar 128 disengages from the first notch portion 118, the inclined portion 122b1 of the rotation-side cam portion 122b of the rotor 112 abuts against the rear inclined portion 110f1 of the main body-side cam portion 110f of the inner tube 110.

[0080] 29, when the knock member 116 is further pushed forward, the rotor 112 advances forward in conjunction with this. At this time, the inclined portion 122b1 of the rotation-side cam portion 122b of the rotor 112 and the rear inclined portion 110f1 of the main body-side cam portion 110f of the inner cylinder 110 are in contact with each other, causing the rotor 112 to rotate.

[0081] Then, as shown in Figure 30, when the rear end (the end on the right side in Figure 30) of the inclined portion 122b1 of the rotation-side cam portion 122b reaches the front end (the end on the left side in Figure 30) of the rear inclined portion 110f1 of the main body-side cam portion 110f, the rotor 112 is pushed back rearward (upward in Figure 30) along the stepped portion 110f2. As a result, as shown in Figure 31, the inclined portion 122b1 of the rotation-side cam portion 122b abuts against the front inclined portion 110f3 of the main body-side cam portion 110f. At this time, the user can feel a clicking sensation (knocking sensation) via the knock member 116.

[0082] 31, when the knock member 116 is further pushed forward, the rotor 112 advances forward in conjunction with this. At this time, the inclined portion 122b1 of the rotation-side cam 122b of the rotor 112 abuts against the front inclined portion 110f3 of the main body-side cam portion 110f of the inner cylinder 110, causing the rotor 112 to rotate. Then, as shown in FIG. 32, when the side surface of the rotation-side cam portion 122b abuts against the side surface 110f0 of the main body-side cam portion 110f, the rotor 112 will no longer rotate even if the knock member 116 is pushed further in.

[0083] When the user releases the knock member 116 from the state shown in FIG. 32, the knock member 116 and the rotor 112 are urged rearward by the spring member 114. As a result, as shown in FIG. 33, the rotor 112 moves rearward, and the rear end surface of the cam pillar 128 abuts against the inclined portion 120a of the cam portion 110b of the inner tube 110. Furthermore, as the rotor 112 moves rearward, the rear end surface of the cam pillar 128 abuts against the inclined portion 120a of the cam portion 110b of the inner tube 110, causing the rotor 112 to rotate. Then, as shown in FIG. 34, the side surface of the cam pillar 128 abuts against the edge portion 120b of the cam portion 110b of the inner tube 110. By the above operation, the brush tip portion 4b of the refill member 4 is held in a state where it protrudes from the tip opening 2a of the barrel 2 (brush forward-extending state).

[0084] Next, to retract the brush tip portion 4b of the refill member 4, the knock member 116 is pushed forward from the state shown in FIG. 34. As shown in FIG. 35, when the knock member 116 is pushed forward, the rotor 112 advances forward in conjunction with this. Then, as shown in FIG. 35, the cam pillar 128 disengages from the second cutout portion 120 of the inner tube 110. Immediately after the cam pillar 128 disengages from the second cutout portion 120, the inclined portion 122b1 of the rotation-side cam portion 122b of the rotor 112 abuts against the rear inclined portion 110f1 of the main body-side cam portion 110f of the inner tube 110.

[0085] 35, when the knock member 116 is further pushed forward, the rotor 112 advances forward in conjunction with this. At this time, the inclined portion 122b1 of the rotation-side cam portion 122b of the rotor 112 and the rear inclined portion 110f1 of the main body-side cam portion 110f of the inner cylinder 110 are in contact with each other, causing the rotor 112 to rotate.

[0086] Then, as shown in Figure 36, when the rear end (the end on the right side in Figure 36) of the inclined portion 122b1 of the rotation-side cam portion 122b reaches the front end (the end on the left side in Figure 36) of the rear inclined portion 110f1 of the body-side cam portion 110f, the rotor 112 is pushed back rearward along the stepped portion 110f2. As a result, as shown in Figure 37, the inclined portion 122b1 of the rotation-side cam portion 122b abuts against the front inclined portion 110f3 of the body-side cam portion 110f. At this time, the user can feel a clicking sensation (knocking sensation) via the knock member 116.

[0087] 37, when the knock member 116 is further pushed forward, the rotor 112 advances forward in conjunction with this. At this time, the inclined portion 122b1 of the rotation-side cam portion 122b of the rotor 112 abuts against the front inclined portion 110f3 of the main body-side cam portion 110f of the inner cylinder 110, causing the rotor 112 to rotate. Then, as shown in FIG. 38, when the rotation-side cam portion 122b reaches the notch 110g1 of the inner cylinder 110, the rotor 112 will no longer rotate even if the knock member 116 is pushed further in.

[0088] When the user releases the knock member 116 from the state shown in Figure 38, the knock member 116 and the rotor 112 are urged rearward by the spring member 114. As a result, as shown in Figure 39, the rotor 112 moves rearward, and the rear end surface of the cam post 128 abuts against the guide portion 118b of the cam portion 110b of the inner cylinder 110. Furthermore, as the rotor 112 moves rearward, the rear end surface of the cam post 128 abuts against the guide portion 118b of the cam portion 110b of the inner cylinder 110, causing the rotor 112 to rotate. 40, when the front end (right side in FIG. 40) of the cam pillar 128 reaches the rear end of the guide portion 118b of the inner cylinder 110, the knock member 116 and the rotor 112 are urged rearward by the spring member 114, and as shown in FIG. 41, the cam pillar 128 enters the axial groove portion 118a of the first notch portion 118 of the inner cylinder 110. This causes the tip portion 4b of the refill member 4 of the knock-type writing instrument to be housed within the barrel 102 (tip housed state).

[0089] According to this embodiment, in addition to the effects achieved in the first embodiment, the following effects are achieved. In this embodiment, the main body side cam portion 110f has a step portion 110f2, which allows the user to feel a knocking sensation when pressing the knock member 116. Furthermore, in this embodiment, the spring member 114 is disposed inside the inner tube 110 and is sandwiched between the reduced diameter portion 110g of the inner tube 110 and the front end of the rear portion 136 of the knock member 116. Therefore, even if the barrel 102 is manufactured from a transparent material, for example, the spring member 114 can be made invisible from the outside.

[0090] Furthermore, according to this embodiment, the brush tip storage state and the brush tip forward state can be switched using only the cam portion 110b and main body side cam portion 110f of the inner tube 110, and the cam pillar 128 and rotation side cam portion 122b of the rotor 112. Since components such as the barrel are not involved in the switching, there are fewer restrictions on the positional relationship of each component, increasing the degree of freedom in design.

[0091] In this embodiment, the case where the main body cam portion 110f includes the rear inclined portion 110f1, the front inclined portion 110f3, and the step portion 110f2 connecting the rear inclined portion 110f1 and the front inclined portion 110f3 has been described, but a step portion may also be provided on the rotation-side cam portion 122b. Furthermore, in other embodiments, a step portion may also be provided on the main body cam portion or the rotation-side cam portion.

[0092] Third Embodiment Next, a third embodiment of the present invention will be described with reference to the drawings. In the following description, the same components as those in the first and second embodiments are designated by the same reference numerals and will not be described in detail. FIG. 42 is a cross-sectional view along the axial direction of a knock-type writing instrument according to a third embodiment of the present invention. A knock-type writing instrument 151 of the third embodiment of the present invention differs from the second embodiment in the arrangement of the spring member 154, but the other components are the same as those of the second embodiment. As shown in FIG. 42, in the knock-type writing instrument 151 of the third embodiment, the spring member 154 is disposed around the tip portion 4b of the refill member 4 inside the barrel 102. In a contracted state, the spring member 154 is interposed between the tip portion 4b of the refill member 4 and the tip end of the barrel 102. With this configuration, the rotor 112 and the knock member 116 are biased rearward via the refill member 4, allowing the tip portion 4b of the refill member 4 to protrude and retract from the tip of the barrel 2, as in the second embodiment. The third embodiment achieves all the effects of the second embodiment except for the effect that the spring member is invisible from the outside.

[0093] <Fourth embodiment> A fourth embodiment of the present invention will be described below with reference to the drawings. In the following description, the same components as those in the first to third embodiments will be denoted by the same reference numerals and detailed description thereof will be omitted. Figure 43 is a cross-sectional view along the axial direction showing a knock-type writing instrument according to a fourth embodiment of the present invention. Also, Figure 44 is an exploded perspective view of the knock-type writing instrument shown in Figure 43. As shown in Figures 43 and 44, a knock-type writing instrument 201 of this embodiment includes a cylindrical barrel 202, a refill member 4 housed in the barrel 202, a retractable mechanism 206 provided at the rear end of the barrel 202, and a clip member 208 connected to the retractable mechanism 206. The barrel 202, the refill member 4, and the retractable mechanism 206 form a writing instrument body.

[0094] Figures 45a and 45b show the barrel of the knock-type writing instrument shown in Figure 43, with Figure 45a being a cross-sectional view along the axial direction and Figure 45b being an enlarged view of part b in Figure 45a. As shown in Figures 45a and 45b, barrel 202 is formed in a cylindrical shape with a tapered tip. A tip opening 202a is formed at the tip end of barrel 202, and a rear end opening 202b is formed at the rear end. A threaded portion 202c is formed on the inner surface of the rear end of barrel 202. In addition, a main body side cam portion 202d is formed in the middle of barrel 202, and the inner diameter of barrel 202 on the rear end side of main body side cam portion 202d is larger than the inner diameter on the tip end side.

[0095] The main body cam portion 202d is formed with a plurality of circumferentially arranged protrusions 202f that protrude rearward. A circumferential surface portion 202f3 facing the rear end is provided between adjacent protrusions 202f. Each protrusion 202f has an edge portion 202f2 that extends axially rearward from one end of the circumferential surface portion 202f3, and an inclined portion 202f1 that extends from the rear end of the edge portion 202f2 to the end of the next circumferential surface portion 202f3.

[0096] As shown in FIGS. 43 and 44, the retractable mechanism 206 includes an inner cylinder 210, a rotor 212, a spring member 214, and a knock member 216. Figures 46a to 46d show the inner barrel of the knock-type writing instrument shown in Figure 43, with Figure 46a being a perspective view, Figure 46b being a front view, Figure 46c being an axial cross-sectional view, and Figure 46d being a bottom view. As shown in Figures 46a to 46d, inner barrel 210 comprises a cylindrical main body portion 210a, a cam portion 210b extending from main body portion 210a toward the tip, a rear end portion 210c connected to the rear end of main body portion 210a, and a clip holding portion 210d extending laterally from rear end portion 210c. Main body portion 210a, cam portion 210b, rear end portion 210c, and clip holding portion 210d are integrally molded.

[0097] The main body 210a is cylindrical, and the outer diameter of the main body 210a is approximately equal to the inner diameter of the barrel 202. A threaded portion 210e is formed on the outer peripheral surface of the main body 210a. In addition, a reduced diameter portion 210g is provided at the front end of the main body 210a, so that the inner diameter becomes smaller.

[0098] The cam portion 210b is substantially cylindrical, and its inner and outer diameters are equal to those of the main body portion 210a. The cam portion 210b has first notches 218 and second notches 220 formed alternately in the circumferential direction. The configuration of the cam portion 210b of the third embodiment is the same as the configuration of the cam portion 10b of the first embodiment, and includes the first notches 218 and the second notches 220, the first notches 218 having an axial groove portion 218a and a guide portion 218b, and the second notches 220 having an edge portion 220b and an inclined portion 220a. The rear end portion 210c is formed in a cylindrical shape with an outer diameter slightly smaller than that of the barrel 2.

[0099] Clip holding portion 210d has a connecting portion 210d1 extending radially outward and forward from rear end portion 210c, a main body portion 210d2 extending forward from the front end of connecting portion 210d1, and holding portion 210d3 formed on the radially inner surface of main body portion 210d2. Holding portion 210d3 extends forward from connecting portion 210d1 and has a T-shaped cross section along its entire length perpendicular to the axial direction.

[0100] Figures 47a to 47c show the rotor of the knock-type writing instrument shown in Figure 43, with Figure 47a being a perspective view, Figure 47b being a front view, and Figure 47c being an exploded view of the front part. As shown in Figures 47a to 47c, rotor 212 has a cylindrical base 221, four cam pillars 228 extending forward from base 221, and holding parts 230 connected to the front ends of cam pillars 228. The base portion 221 has a cylindrical main body portion 222 , a rear end portion 224 connected to the rear end side of the main body portion 222 , and an annular portion 226 connected to the front end side of the main body portion 222 .

[0101] The main body 222 is formed in a cylindrical shape.

[0102] The rear end portion 224 includes an intermediate cylindrical portion 224a that is continuous with the rear end of the main body portion 222 and has a smaller diameter than the knock member 216 (described later), an annular recess 224b that is continuous with the rear end of the intermediate cylindrical portion 224a, a truncated conical portion 224c that is continuous with the rear end of the annular recess 224b, and a cylindrical portion 224d that is continuous with the rear end of the truncated conical portion 224c. The intermediate cylindrical portion 224a and the cylindrical portion 224d are cylindrical portions with approximately the same diameter. The annular recess 224b has the same circular cross-sectional shape in the axial direction and a smaller diameter than the intermediate cylindrical portion 224a. The truncated conical portion 224c has a truncated conical shape with a larger diameter at the tip end, and the diameter at the front end is larger than the diameter of the annular recess 224b and the diameter at the rear end is equal to the diameter of the cylindrical portion 224d.

[0103] The annular portion 226 is connected to the front end of the main body portion 222 and has an annular shape. The outer diameter of the annular portion 226 is larger than the outer diameter of the main body portion 222 and smaller than the outer diameter of the holding portion 230. The configuration of the cam pillar 228 in the fourth embodiment is substantially the same as the configuration of the cam pillar 28 in the first embodiment.

[0104] The holding portion 230 is formed in an annular shape and is connected to the front end of the cam pillar 228. A rotation-side cam portion 230a is formed on the front surface of the holding portion 230 along the circumferential direction. The rotation-side cam portion 230a is formed at 90° intervals and has protrusions 230a0 that protrude toward the tip. Each protrusion 230a0 has an edge portion 230a1 that extends in the axial direction and an inclined portion 230a2 that is inclined in the circumferential direction. A flat portion 230a3 that extends in the circumferential direction is formed between each protrusion 230a0. The spring member 214 is a spring member made of a spiral metal member.

[0105] Figures 48a to 48c show the knock member of the knock-type writing instrument shown in Figure 43, with Figure 48a being a perspective view, Figure 48b being a front view, and Figure 48c being a cross-sectional view along the axial direction. Knock member 216 has a front portion 232 and a rear portion 236 that continues to the rear of front portion 232 and has a larger outer diameter than front portion 232. The outer diameters of front portion 232 and rear portion 236 are slightly smaller than the inner diameter of main body portion 210a of inner tube 210. Knock member 216 is formed with a through-hole 216a that passes through in the axial direction. Furthermore, an annular locking portion 216b that protrudes radially inward is formed in the middle of through-hole 216a.

[0106] 49a and 49b show the clip member of the knock-type writing instrument shown in FIG. 43, with FIG. 49a being a perspective view and FIG. 49b being a front view. As shown in FIGS. 49a and 49b, clip member 208 includes connecting portion 208a, stem portion 208b extending axially forward from connecting portion 208a, and planar flat portion 208e extending laterally from stem portion 208b. Connecting portion 208a is formed with notch 208c extending axially. Furthermore, protrusions 208d protruding toward the center of notch 208c are formed on both radially outer edges of notch 208c. As shown in FIG. 43, retaining portion 210d3 of inner tube 210 is accommodated in notch 208c of clip member 208, thereby fixing clip member 208 to inner tube 210 so as to be positioned laterally of stem tube 202. The clip member 208 has a through hole formed in the flat portion 208e, which allows a lens unit to be attached, making it possible to enlarge and read letters through the lens unit, or it can be formed from a thermoplastic elastomer and used as a friction tool when made into a thermochromic writing instrument.

[0107] 50 is an enlarged cross-sectional view taken along the axial direction of the rear end portion of the clip member of the knock-type writing implement shown in FIG. 50, in an assembled state, threaded portion 210e of inner cylinder 210 is threadedly engaged with threaded portion 202c of barrel cylinder 202, and inner cylinder 210 is attached to the rear end of barrel cylinder 202. In addition, clip member 208 is attached to clip holding portion 210d of inner cylinder portion 210.

[0108] A main body 222 and a rear end 224 of the rotor 212 are inserted into the through hole of the inner cylinder 210 from the front end side. A spring member 214 is inserted into the through hole of the inner cylinder 210 from the rear end side, and a knock member 216 is inserted from behind the spring member 214. The rear end 224 of the rotor 212 fits into the through hole of the knock member 216 from the front.

[0109] The rotor 212 is inserted into the knock member 216 from the front until the truncated cone portion 224c formed on the base 221 exceeds the locking portion 216b of the knock member 216, and the locking portion 216b of the knock member 216 is located within the annular recess 224b of the rotor 212.

[0110] Additionally, the cam portion 210b of the inner cylinder 210 and the cam pillar 228 of the rotor 212 are aligned along the inner surface of the shaft cylinder 202 and are positioned on the same circle. Additionally, the rotation-side cam portion 230a of the rotor 212 and the main body-side cam portion 202d of the shaft cylinder 202 are positioned on the same circle. The spring member 214 is disposed on the outer periphery of the base portion 221 of the rotor 112 and is held in a contracted state between the reduced diameter portion 210 g of the inner cylinder 210 and the rear portion 236 of the knock member 216 .

[0111] With this configuration, locking portion 216b of knock member 216 fits into annular recess 224b of rotor 212, and is sandwiched between intermediate cylindrical portion 224a and truncated cone portion 224c of rotor 212 at the front and rear, thereby restricting relative axial movement between knock member 216 and rotor 112. Furthermore, knock member 216 and rotor 212 are movable in the axial direction relative to inner tube 210 and shaft tube 202, and knock member 216 is urged rearward by spring member 214. In other words, base portion 221 of rotor 212 is held by knock member 216, and rotation-side cam portion 230a is movable relative to main body-side cam portion 202d.

[0112] The rear end of the refill member 4 is inserted into the annular holding portion 230 of the rotor 212 and abuts against the front surface of the annular portion 226. This allows the refill member 4 to be held by the rotor 212 so as to be able to be fed out and pulled back.

[0113] Next, the operation of extending and retracting the writing tip of the knock-type writing instrument of this embodiment will be described. Figures 51 to 60 are diagrams for explaining the extension and retraction operation of the writing tip using the knock-type writing instrument shown in Figure 43. Figures 51 to 60 show an expanded view of the cam portion 210b of the inner tube 210, the cam pillar 228 and rotation-side cam portion 230a of the rotor 212, and the main body-side cam portion 202d of the barrel 202. In Figures 51 to 60, the cam pillar 228 and rotation-side cam portion 230a of the rotor 212 are shown by solid lines, the cam portion 210b of the inner tube 210 is shown by dashed lines, and the main body-side cam portion 202d of the barrel 202 is shown by chain lines.

[0114] Figure 51 shows a state (tip-stored state) in which the tip 4b of the refill member 4 of the knock-type writing instrument is stored in the barrel 202. As shown in Figure 51, the knock member 216 is urged rearward by the spring member 214, and thus the rotor 212 is urged rearward together with the knock member 216, and the cam pillar 228 of the rotor 212 enters the first notch 218 of the inner cylinder 210, and the rear end of the cam pillar 228 abuts against the bottom of the first notch 218.

[0115] First, in order to advance the brush tip portion 4b of the refill member 4 from the state shown in Figure 51, the knock member 216 is pushed forward. When the knock member 216 is pushed forward, the rotor 212 advances forward in conjunction with this. Then, as shown in Figure 52, the cam pillar 228 disengages from the first notch portion 218 of the inner tube 210. Furthermore, after the cam pillar 228 disengages from the first notch portion 218, the inclined portion 230a2 of the rotation-side cam portion 230a of the rotor 212 abuts against the inclined portion 202f1 of the main body-side cam portion 202d of the barrel tube 202.

[0116] Next, when the knock member 216 is further pushed forward from the state shown in Fig. 52, the rotor 212 advances forward in conjunction with this. At this time, the inclined portion 230a2 of the rotation-side cam portion 230a of the rotor 212 abuts against the inclined portion 202f1 of the main body-side cam portion 202d of the barrel 202, causing the rotor 212 to rotate. Then, as shown in Fig. 53, when the tip end of the inclined portion 230a2 of the rotation-side cam portion 230a reaches the tip end of the inclined portion 202f1 of the main body-side cam portion 202d, the knock member 216 can no longer be pushed in any further.

[0117] When the user releases the knock member 216 from the state shown in FIG. 53, the knock member 216 and the rotor 212 are urged rearward by the spring member 214. As a result, as shown in FIG. 54, the rotor 212 moves rearward, and the rear end surface of the cam post 228 abuts against the inclined portion 220a of the cam portion 210b of the inner tube 210. Furthermore, as the rotor 212 moves rearward, the rear end surface of the cam post 228 abuts against the inclined portion 220a of the cam portion 210b of the inner tube 210, causing the rotor 212 to rotate leftward in FIG. 54. Then, as shown in FIG. 55, the side surface of the cam post 228 abuts against the edge portion 220b of the cam portion 210b of the inner tube 210. By the above operation, the brush tip portion 4b of the refill member 4 is held in a state where it protrudes from the tip opening 202a of the barrel tube 202 (brush forward-extending state).

[0118] Next, to retract the brush tip portion 4b of the refill member 4, the knock member 216 is pushed forward from the state shown in FIG. 55. When the knock member 216 is pushed forward, the rotor 212 advances forward in conjunction with this. Then, as shown in FIG. 56, the cam pillar 228 disengages from the second notch portion 220 of the inner tube 210. Furthermore, after the cam pillar 228 disengages from the second notch portion 220, the inclined portion 230a2 of the rotation-side cam portion 230a of the rotor 212 abuts against the inclined portion 202f1 of the main body-side cam portion 202d of the barrel tube 202. Next, when the knock member 216 is further pushed forward from the state shown in Figure 56, the rotor 212 advances forward in conjunction with this. At this time, the inclined portion 230a2 of the rotation-side cam portion 230a of the rotor 212 abuts against the inclined portion 202f1 of the main body-side cam portion 202d of the barrel 202, causing the rotor 212 to rotate. Then, as shown in Figure 57, when the tip end of the inclined portion 230a2 of the rotation-side cam portion 230a reaches the tip end of the inclined portion 202f1 of the main body-side cam portion 202d, the knock member 216 can no longer be pushed in any further.

[0119] When the user releases the knock member 216 from the state shown in Figure 57, the knock member 216 and the rotor 212 are urged rearward by the spring member 214. As a result, as shown in Figure 58, the rotor 212 moves rearward, and the rear end surface of the cam pillar 228 comes into contact with the guide portion 218b of the cam portion 210b of the inner cylinder 210. Furthermore, as the rotor 212 moves rearward, the rear end surface of the cam pillar 228 comes into contact with the guide portion 218b of the cam portion 210b of the inner cylinder 210, and the rotor 212 rotates in the left direction in Figure 58. 59, when the front end of the cam pillar 228 reaches the rear end of the guide portion 218b of the inner cylinder 210, the knock member 216 and the rotor 212 are urged rearward by the spring member 214, and as shown in Figure 60, the cam pillar 228 enters the axial groove portion 218a of the first notch portion 218 of the inner cylinder 210. By the above operation, the tip portion 4b of the refill member 4 of the knock-type writing instrument is accommodated in the barrel 102 (tip accommodated state). The fourth embodiment also provides the same effects as the first and second embodiments.

[0120] Fifth Embodiment A writing instrument according to a fifth embodiment of the present invention will now be described in detail with reference to the drawings. Fig. 61 is a perspective view showing a writing instrument according to a fifth embodiment of the present invention. Fig. 62a is a side view of the writing instrument shown in Fig. 61, and Fig. 62b is a cross-sectional view taken along the axial direction. As shown in Figs. 61, 62a, and 62b, a knock-type writing instrument 301 of this embodiment comprises a cylindrical barrel 302, a refill member 304 housed in barrel 302, a retractable mechanism 306 provided at the rear end of barrel 302, and a clip member 308 connected to retractable mechanism 306. Barrel 302, refill member 304, and retractable mechanism 306 form the writing instrument body.

[0121] Figures 63a and 63b show the barrel of the writing implement shown in Figure 61, with Figure 63a being an axial cross-sectional view and Figure 63b being a perspective view of the rear end. As shown in Figures 63a and 63b, barrel 302 is formed in a cylindrical shape with a tapered tip. A tip opening 302a is formed at the tip of barrel 302, and a rear opening 302b is formed at the rear end. A screw portion (thread) 302c is formed on the inner surface of the rear end of barrel 302. Furthermore, a step 302d is formed in the middle of the barrel 302, and the inner diameter of the barrel 302 rearward of the step 302d is larger than the inner diameter at the tip. A triangular notch 302e is formed at a predetermined angular position on the rear edge of the barrel 302. Furthermore, a through-hole 302f is formed in front of the notch 302e, which allows elastic deformation when a protrusion 310d5 fits into the inner barrel 310 that constitutes the retractable mechanism 306 when it is attached by screwing. Note that in this embodiment, no protrusion is formed on the portion of the barrel 302 that corresponds to the connecting mechanism for connecting the clip.

[0122] Figures 64a to 64d show the inner barrel of the knock-type writing instrument shown in Figure 61, with Figure 64a being a perspective view, Figure 64b being a front view, Figure 64c being a cross-sectional view along the axial direction, and Figure 64d being a bottom view. As shown in Figures 64a to 64d, inner barrel 310 comprises a cylindrical main body portion 310a, a cam portion 310b extending from main body portion 310a toward the tip, a rear end portion 310c connected to the rear end of main body portion 310a, and a clip holder 310d extending laterally from rear end portion 310c. Main body portion 310a, cam portion 310b, rear end portion 310c, and clip holder 310d are integrally molded.

[0123] The main body 310a is cylindrical, and the outer diameter of the main body 310a is approximately equal to the inner diameter of the barrel 2. A threaded portion (thread) 310e is formed on the outer peripheral surface of the main body 310a. Furthermore, axial protrusions 310f extending in the axial direction are formed on the inner peripheral surface of the main body 310a at opposing positions spaced apart by an angle of 180 degrees.

[0124] The cam portion 310b is substantially cylindrical, and its inner and outer diameters are equal to those of the main body portion 310a. As shown in FIG. 64a, the cam portion 310b has first notches 318 and second notches 320 formed alternately in the circumferential direction. The first notches 318 have axial grooves 318a extending axially rearward from the leading edge and guide portions 318b formed contiguous with the axial grooves 318a in a clockwise direction (to the right in FIG. 64b). The axial grooves 318a are grooves that extend axially with a constant circumferential width and extend further rearward than the second notches 320. The guide portions 318b are formed in a triangular shape such that the cutting depth (distance from the leading edge of the inner cylinder) decreases clockwise when viewed from the circumferential surface. The second notches 320 are formed in a triangular shape such that the cutting depth decreases clockwise when viewed from the circumferential surface. The maximum cutting depth of the second cutout portion 320 is smaller than the cutting depth of the axial groove portion 318a of the first cutout portion 318 and larger than the maximum cutting depth of the guide portion 318b. The position of the counterclockwise end (left direction in FIG. 64b) of the second cutout portion 320 coincides with the position of the clockwise end of the guide portion 318b of the adjacent first cutout portion 318. In addition, the position of the clockwise end of the second cutout portion 320 coincides with the position of the counterclockwise end of the axial groove 318a of the adjacent first cutout portion 318. The rear end portion 310c is formed in a cylindrical shape with an outer diameter slightly smaller than the outer diameter of the barrel 302.

[0125] The clip holder 310d includes a connecting portion 310d1 extending radially outward and forward from the rear end 310c, a main body portion 310d2 extending forward from the front end of the connecting portion 310d1, a first holder portion 310d3 formed on the radially inner surface of the main body portion 310d2, and a second holder portion 310d4 formed contiguous with the first holder portion 310d3. The first holder portion 310d3 includes a base portion 310d3a extending axially from the inner surface of the main body portion 310d2, and a widened portion 310d3b formed radially inward of the base portion 310d3a. The cross section of the plane perpendicular to the axial direction is T-shaped. The width of the second holder portion 310d4 is equal to the widened portion 310d3b of the first holder portion 310d3. A protrusion 310d5 is formed on the surface of the tip end side (lower side in FIG. 64b) of the second holding portion 310d4.

[0126] Figures 65a and 65b show the rotor of the knock-type writing instrument shown in Figure 61, with Figure 65a being a perspective view and Figure 65b being a front view. As shown in Figures 65a and 65b, rotor 312 has a cylindrical base 321, four cam posts 328 extending forward from base 321, and holders 330 connected to the front ends of cam posts 328. The base 321 has a cylindrical main body 322, an annular rear end 324 connected to the rear end of the main body 322, and an annular ring 326 connected to the front end of the main body 322.

[0127] The main body 322 is formed in a cylindrical shape, and its outer diameter is slightly smaller than the inner diameter of the front portion of the knock member 316, which will be described later. The rear end of the main body 322 has a tapered portion 322a whose diameter tapers rearward.

[0128] The rear end portion 324 has a cylindrical portion 324a that is continuous with the rear end of the main body portion 322, a truncated cone-shaped (frustum-shaped) truncated cone portion 324b that is continuous with the rear end of the cylindrical portion 324a, and an indicator portion 324c that is continuous with the rear end of the truncated cone portion 324b. The cylindrical portion 324a has a circular cross-sectional shape that is constant in the axial direction. The outer diameter of the cylindrical portion 324a is slightly smaller than the inner diameter of the rear portion 336 of the knock member 316. The truncated cone portion 324b has a truncated cone shape with a larger diameter at the tip end. The diameter of the rear end of the truncated cone portion 324b is approximately equal to the diameters of the cylindrical portion 324a and the indicator portion 324c. The indicator portion 324c is a cylindrical portion that extends rearward from the rear end of the truncated cone portion 324b. The indicator portion 324c has multiple grooves that extend in the axial direction.

[0129] The annular portion 326 is connected to the front end of the main body portion 322 and is formed in an annular shape. The outer diameter of the annular portion 326 is larger than the outer diameter of the main body portion 322 and smaller than the outer diameter of the holding portion 330. A rotation-side cam portion 326b is formed on the rear surface of the annular portion 326. The rotation-side cam portion 326b includes four cam protrusions 326a formed at 90-degree intervals in the circumferential direction. The cam protrusions 326a are in the shape of an isosceles triangle that protrudes rearward.

[0130] The cam posts 328 have an arcuate cross-sectional shape in a plane perpendicular to the axial direction, are connected to the radially outer peripheral surface of the annular portion 326 of the base 321, and extend forward. The cam posts 328 are attached at 90-degree intervals in the circumferential direction. The cam posts 328 have a circumferential width that is half that of the cam protrusions 326a formed on the annular portion 326. Each cam post 328 is connected to the outer surface of the right half of the cam protrusions 326a of the annular portion 326 in Figure 65b. The rear end surface of the cam post 328 is flush with the rear end surface of the clockwise half of the cam protrusions 326a of the annular portion 326. In other words, the rear end surface of the cam post 328 is formed as an inclined portion so that its protruding height toward the rear decreases in the clockwise direction.

[0131] The holding portion 330 is formed in an annular shape. The inner and outer diameters of the holding portion 330 are equal to the inner and outer diameters of the cam pillar 328. The spring member 314 is a spring member made of a spiral metal member.

[0132] Figures 66a to 66c show a knock member of the knock-type writing instrument shown in Figure 61, with Figure 66a being a perspective view, Figure 66b being a front view, and Figure 66c being a cross-sectional view along the axial direction. Knock member 316 has a front portion 332, an intermediate portion 334 continuing to the rear of the front portion, and a rear portion 336 continuing to the rear of intermediate portion 334. The front portion 332 has a cylindrical internal space that is open at least forward, and is formed by a pair of wall surfaces with an arc-shaped cross section. The outer diameter of the front portion 332 is slightly smaller than the inner diameter of the main body portion 310a of the inner cylinder 310. The inner diameter of the front portion 332 is slightly larger than the outer diameter of the main body portion 322 of the knock member 316. A pair of axial grooves 332a are formed in the front portion 332, open forward, and extend a predetermined distance rearward, spaced circumferentially at 180-degree intervals. A main body cam portion 332b is formed on the end face of the front end of the front portion 332. The main body cam portion 332b includes three triangular protrusions 332b1, 332b2, and 332b3 that are formed between the pair of axial grooves 332a and aligned circumferentially. As will be described later, when knock member 316 is pressed in, rotor 312 is rotated by a predetermined angle by main body side cam portion 332b of knock member 316 and rotation side cam portion 326b of rotor 312.

[0133] Intermediate portion 334 is formed in an annular shape, and has locking portion 334b ​​formed on the inner surface thereof so as to protrude in an annular shape. The front portion of locking portion 334b ​​is preferably formed with a sloped portion that tapers in diameter toward the rear, as shown in Figure 66c. The rear portion 336 is formed in a cylindrical shape, and the opposing portions of the outer circumferential surface are formed flat.

[0134] 61, the knock member 316 is inserted into the inner cylinder 310 from the rear so that the axial protrusion 310f of the inner cylinder 310 is positioned in the axial groove 332a of the knock member 316. The rotor 312 is inserted into the knock member 316 from the front to a position where the truncated cone portion 324b formed on the base 321 exceeds the locking portion 334b ​​of the knock member 316. The cam portion 310b of the inner cylinder 310 and the cam post 328 of the rotor 312 are aligned along the inner surface of the shaft cylinder 302 and are positioned on the same circle.

[0135] With this configuration, the rotation of knock member 316 is restricted with respect to inner cylinder 310, and is movable in the axial direction relative to inner cylinder 310. Furthermore, rotor 312 is rotatable with respect to knock member 316, and is also movable in the axial direction relative to inner cylinder 310 between a position where locking portion 334b ​​of knock member 316 abuts against truncated cone portion 324b of rotor 312 and a position where protrusions 332b1, 332b2, and 332b3 of knock member 316 abut against cam protrusion 326a of rotor 312. In other words, base 321 of rotor 312 is held by knock member 316, and rotation-side cam portion 326b can move relative to main body-side cam portion 332b.

[0136] The main body portion 310a and cam portion 310b of the inner tube 310 are accommodated in the rear end opening 302b of the barrel 302, and the threaded portion of the barrel 302 and the threaded portion 310e of the inner tube 310 are threadedly engaged with each other, thereby attaching the inner tube 310 to the rear end of the barrel 302.

[0137] The rear end of the refill member 304 is inserted into the annular holding portion 330 of the rotor 312 and abuts against the front surface of the annular portion 326. This allows the refill member 304 to be held by the rotor 312 so as to be able to be extended and retracted.

[0138] Furthermore, spring member 314 is disposed between refill member 304 and barrel 302. In a contracted state, spring member 314 is sandwiched between step portion 302d of barrel 302 and holding portion 330 of rotor 312. As a result, rotor 312 is biased rearward by spring member 314.

[0139] The retraction mechanism of the knock-type writing instrument of this embodiment has the same configuration as that of the first embodiment. That is, by pressing the knock member 316 against the biasing force of the spring member 314, the rotor 312 moves forward and rotates relative to the inner tube 310. This allows the cam pillar 328 of the rotor 312 to be switched between a state in which it is housed in the first notch 318 of the inner tube 310 and a state in which it is housed in the second notch 320. This allows the rotor 312 to be switched between a state in which the brush tip 304b of the refill member 304 held by the rotor 312 is housed within the barrel 302 (brush tip housed state) and a state in which the brush tip 304b of the refill member 304 protrudes from the tip opening 302a of the barrel 302 (brush tip advanced state).

[0140] Figures 67a to 67c show the clip member of the knock-type writing instrument shown in Figure 61, with Figure 67a being a perspective view, Figure 67b being a front view, and Figure 67c being a side view. As shown in Figures 67a to 67c, clip member 308 comprises connecting portion 308a and main body portion 308b extending axially forward from connecting portion 308a. Connecting portion 308a comprises base portion 308a1 extending axially and tip portion 308a2 extending radially inward from the tip of base portion 308a1. Connecting portion 308a is formed with notch 308c extending from tip portion 308a2 to base portion 308a1. Furthermore, side edges 308d that protrude toward the center of the cutout 308c are formed on both radially outer edges of the cutout 308c in the base 308a1.

[0141] Next, the mechanism for connecting the clip member 308 and the barrel 302 will be described. When the threaded portion 310e of the inner tube 310 is threadedly engaged with the threaded portion 302c of the barrel 302, the protrusion 310d5 of the clip holder 310d enters and locks into the notch 302e of the barrel 2. In this state, the base 310d3a of the first holder 310d3 of the inner tube 310 is inserted into the notch 308c of the clip member 308, and the holder 310d is fitted into the notch 308c. As a result, the side edge 308d of the clip member 308 is sandwiched between the main body 310d2 and the widened portion 310d3b of the clip holder 310d. Furthermore, as shown in FIG. 62a, the tip 308a2 of the clip member 308 is sandwiched between the connecting portion 310d1 of the inner tube 310 and the barrel 302 from the front and rear. As a result, the clip member 308 is fixedly connected to the barrel 302 so as to be positioned to the side of the barrel 302.

[0142] Note that clip member 308 can be attached to inner tube 310 of protrusion / retraction mechanism 306 in advance before attaching protrusion / retraction mechanism 306 to barrel tube 302, and clip member 308 can be attached to barrel tube 302 together with protrusion / retraction mechanism 306 by threading threaded portion 310e of inner tube 310 of protrusion / retraction mechanism 306 into threaded portion 302c of barrel tube 302. Conversely, clip member 308 can be removed from barrel tube 302 by removing inner tube 310 from barrel tube 302 and then removing clip member 308 from inner tube 310.

[0143] In this embodiment, the clip member 308 is fixed to the inner tube 310 by providing a notch 308c in the clip member 308, providing a first holding portion 310d3 in the inner tube 310, and fitting the first holding portion 310d3 into the notch 308c. However, this is not limited to this, and the clip member may be provided with a holding portion that protrudes from the surface and extends in the axial direction, and a notch that extends in the axial direction may be provided in the clip holding portion of the inner tube, and the holding portion may be fitted into the notch to fix it.

[0144] As described above, according to this embodiment, the following effects are achieved in addition to the effects achieved in the first embodiment. In this embodiment, the clip member 308 can be removably attached to the writing instrument body by fitting the notch 308c of the clip member 308 into the first holding portion 310d3 formed in the clip holding portion 310d of the inner tube 310. Furthermore, according to this embodiment having such a configuration, since no protrusions are formed on the outer periphery of the rear end of the barrel 302, processing such as printing can be easily performed on the outer surface of the barrel 302. The clip holding mechanism of this embodiment can also be employed in other embodiments.

[0145] Sixth Embodiment A writing instrument according to a sixth embodiment of the present invention will now be described in detail with reference to the drawings. FIG. 68 is an axial cross-sectional view showing a writing implement according to a sixth embodiment of the present invention. 68, a knock-type writing instrument 401 of this embodiment includes a cylindrical barrel 402, a refill member 404 housed in barrel 402, a retractable mechanism 406 provided at the rear end of barrel 402, and a clip member 408 connected to retractable mechanism 406. Barrel 402, refill member 404, and retractable mechanism 406 form the writing instrument body.

[0146] The barrel 402 is formed in a cylindrical shape with a tapered tip. The barrel 402 is formed in a cylindrical shape with a tapered tip. A tip opening 402a is formed at the tip of the barrel 402, and a rear end opening 402b is formed at the rear end. A threaded portion is formed on the inner surface of the rear end of the barrel 402. In addition, a step 402d is formed in the middle of the barrel 402, and the inner diameter of the barrel 402 on the rear end side of the step 402d is larger than the inner diameter on the tip side.

[0147] The refill member 404 includes an ink storage section 404a that stores ink, and a brush tip section 404b that is connected to the tip of the ink storage section 404a. The ink storage section 404a stores water-based or oil-based ink. The ink stored in the ink storage section 404a is supplied to the brush tip section 404b. The ink is transferred to the paper surface by contacting the transfer ball at the tip of the brush tip section 404b with the paper surface.

[0148] Figures 69a to 69d show the retraction mechanism of the knock-type writing instrument shown in Figure 68, with Figure 69a being a perspective view, Figure 69b being a side view, Figure 69c being a rear view, and Figure 69d being a cross-sectional view along the axial direction. Note that the spring member is not shown in Figures 69a to 69d. As shown in Figure 68 and Figures 68a to 69d, retraction mechanism 406 includes inner tube 410, rotor 412, spring member 414, and knock member 416.

[0149] Figures 70a to 70d show the inner barrel of the knock-type writing instrument shown in Figure 68, with Figure 70a being a perspective view, Figure 70b being a top view, Figure 70c being a side view, and Figure 70d being a cross-sectional view along the axial direction. As shown in Figures 70a to 70d, inner barrel 410 comprises a cylindrical main body portion 410a, a cam portion 410b extending from main body portion 410a toward the tip, a rear end portion 410c connected to the rear end of main body portion 410a, and a clip holder 410d extending laterally from rear end portion 410c. Main body portion 410a, cam portion 410b, rear end portion 410c, and clip holder 410d are integrally molded.

[0150] The main body 410a is cylindrical, and the outer diameter of the main body 410a is approximately equal to the inner diameter of the barrel 402. A threaded portion 410e is formed on the outer peripheral surface of the main body 410a. Furthermore, axial protrusions 410f extending in the axial direction are formed on the inner peripheral surface of the main body 410a at opposing positions spaced apart by an angle of 180 degrees.

[0151] The cam portion 410b is substantially cylindrical, and its inner and outer diameters are equal to those of the main body portion 410a. The cam portion 410b has first notches 418 and second notches 420 alternately formed at equal angular (90-degree) intervals in the circumferential direction. Each first notch 418 has an axial groove 418a extending axially rearward from its leading edge, and a guide portion 418b formed contiguous with the axial groove 418a in a clockwise direction (to the right in FIG. 70c). The axial groove 418a is a groove extending axially with a constant circumferential width and extends further rearward than the second notch 420. The guide portion 418b is formed in a triangular shape such that the cutting depth (distance from the leading edge of the inner cylinder) decreases clockwise when viewed from the circumferential surface. The second notch 420 is formed in a triangular shape such that the cutting depth decreases clockwise when viewed from the circumferential surface. The maximum cutting depth of the second cutout portion 420 is smaller than the cutting depth of the axial groove portion 418a of the first cutout portion 418 and larger than the maximum cutting depth of the guide portion 418b. The position of the counterclockwise end (left direction in FIG. 70c ) of the second cutout portion 420 coincides with the position of the clockwise end of the guide portion 418b of the adjacent first cutout portion 418. In addition, the position of the clockwise end of the second cutout portion 420 coincides with the position of the counterclockwise end of the axial groove 418a of the adjacent first cutout portion 418.

[0152] The rear end portion 410c is formed in a cylindrical shape with an outer diameter slightly smaller than that of the barrel 402. The clip holding portion 410d extends radially outward from the rear end portion 410c and has an opening 410d1 extending in the axial direction.

[0153] Figures 71a to 71d show the rotor of the knock-type writing instrument shown in Figure 68, with Figure 71a being a perspective view, Figure 71b being a front view, Figure 71c being a top view, and Figure 71d being a cross-sectional view taken along line dd in Figure 71b. As shown in Figures 71a to 71d, rotor 412 has a cylindrical base 421, four cam pillars 428 extending forward from base 421, and holding portions 430 connected to the front ends of cam pillars 428. The base portion 421 has a cylindrical main body portion 422 , a rear end portion 424 connected to the rear end side of the main body portion 422 , and an annular portion 426 connected to the front end side of the main body portion 422 .

[0154] Main body 422 is formed in a cylindrical shape, and its outer diameter is slightly smaller than the inner diameter of the front portion of knock member 416, which will be described later. Main body 422 has a rear end portion with a reduced diameter 422a, the diameter of which decreases rearward.

[0155] Rear end portion 424 has a cylindrical portion 424a continuing to the rear end of main body portion 422, a truncated cone-shaped (frustum-shaped) truncated cone portion 424b continuing to the rear end of cylindrical portion 424a, and a first display portion 424c continuing to the rear end of truncated cone portion 424b. Cylindrical portion 424a has a circular cross-sectional shape that is uniform in the axial direction. The outer diameter of the cylindrical portion 424a is slightly smaller than the inner diameter of the rear portion 436 of the knock member 416. The truncated cone portion 424b has a truncated cone shape with a larger diameter at the tip end. The diameter of the rear end of the truncated cone portion 424b is approximately equal to the diameters of the cylindrical portion 424a and the first indicating portion 424c. The first indicating portion 424c is a cylindrical portion extending rearward from the rear end of the truncated cone portion 424b. A plurality of grooves 424d extending in the axial direction are formed in the first indicating portion 424c. The width and depth of these grooves 424d are determined taking into account the density and viscosity of the ink so that the ink is drawn into the grooves 424d by capillary action. The width is 0.05 mm to 2 mm, and the depth is 0.05 mm to 2 mm. Each groove 424d holds the same dried ink as that contained in the ink containing portion 404a of the refill member 404.

[0156] The annular portion 426 is connected to the front end of the main body portion 422 and is formed in an annular shape. The outer diameter of the annular portion 426 is larger than the outer diameter of the main body portion 422, smaller than the outer diameter of the holding portion 430, and approximately equal to the inner diameter of the cam pillar 428. A rotation-side cam portion 426b is formed on the rear surface of the annular portion 426. The rotation-side cam portion 426b includes four cam protrusions 426a formed at 90-degree intervals in the circumferential direction. The cam protrusions 426a are formed in an isosceles triangular shape such that the protruding height (rearward length) decreases from the center toward the sides in the circumferential direction.

[0157] The cam pillars 428 have an arc-shaped cross section perpendicular to the axial direction, are connected to the radially outer peripheral surface of the annular portion 426 of the base portion 421, and extend forward. The cam pillars 428 are attached at 90-degree intervals in the circumferential direction. The cam pillars 428 have a circumferential width that is half that of the cam projections 426a formed on the annular portion 426. Each cam pillar 428 is connected to the outer surface of the right half of the cam projections 426a of the annular portion 426 in FIG. 71b. The rear end surface of the cam pillar 428 is flush with the rear end surface of the clockwise half of the cam projections 426a of the annular portion 426. In other words, the rear end surface 428a of the cam pillar 428 is formed as an inclined portion so that its protruding height toward the rear decreases in the clockwise direction.

[0158] The holding portion 430 is formed in an annular shape. The inner and outer diameters of the holding portion 430 are substantially equal to the inner and outer diameters of the cam pillar 428. The spring member 414 is a spring member made of a spiral metal member.

[0159] 72a to 72c show the knock member of the knock-type writing implement shown in FIG. 68, with FIG. 72a being a perspective view, FIG. 72b being a front view, and FIG. 72c being a cross-sectional view along the axial direction. The knock member 416 is made of a transparent or semi-transparent resin that allows visibility. The knock member 416 has a front portion 432, a middle portion 434 that is continuous with the rear of the front portion 432, and a rear portion 436 that is continuous with the rear of the middle portion 434.

[0160] The front portion 432 has a cylindrical internal space that is open at least forward, and is formed by a pair of wall surfaces with an arc-shaped cross section. The outer diameter of the front portion 432 is slightly smaller than the inner diameter of the main body portion 410a of the inner cylinder 410. The inner diameter of the front portion 432 is also slightly larger than the outer diameter of the main body portion 422 of the knock member 416. A pair of axial grooves 432a are formed in the front portion 432, open forward, and extend a predetermined distance rearward, spaced circumferentially at 180-degree intervals. A main body cam portion 432b is formed on the end face of the front end of the front portion 432. The main body cam portion 432b includes three triangular protrusions 432b1, 432b2, and 432b3 that are formed between the pair of axial grooves 432a and aligned circumferentially. As will be described later, when knock member 416 is pressed in, rotor 412 is rotated by a predetermined angle by main body side cam portion 432b of knock member 416 and rotation side cam portion 426b of rotor 412.

[0161] The middle portion 434 is formed in an annular shape, and a locking portion 434b is formed on the inner surface thereof so as to protrude in an annular shape. The front portion of the locking portion 434b is preferably formed with a sloped portion that narrows in diameter toward the rear, as shown in Figure 72c. The rear portion 436 is formed in a cylindrical shape.

[0162] 73a to 73c show the clip member of the knock-type writing instrument shown in FIG. 68, with FIG. 73a being a perspective view from the radially outer side, FIG. 73b being a perspective view from the radially inner side, and FIG. 73c being a side view from the radially inner side. Clip member 408 is formed of a transparent or translucent resin that allows visibility. As shown in FIGS. 73a to 73c, clip member 408 includes a connecting portion 408a and a main body portion 8b extending forward from connecting portion 408a. The cross-sectional shape of connecting portion 408a is the same as the opening 410d1 of inner tube 410. As shown in FIG. 68, by inserting connecting portion 408a of clip member 408 into opening 410d1 of inner tube 410, clip member 408 is fixed to inner tube 410 so as to be positioned to the side of barrel 402.

[0163] A second display portion 408c is provided on the inner surface (the surface facing the barrel 2) of the main body portion 408b of the clip member 408. The second display portion 408c comprises a character groove portion 408d1 formed by a groove shaped like a left-right inverted version of the word "HELLO," a connecting groove portion 408d2 formed by a groove connecting the bottom of each character in the character groove portion 408d1, and a substantially circular reservoir portion 408d3 provided at the end of the connecting groove portion 408d2. The width and depth of the character groove portion 408d1 and the connecting groove portion 408d2 are determined taking into consideration the density and viscosity of the ink so that the ink is drawn into the groove portion 408d1 and the connecting groove portion 408d2 by capillary action. The width is 0.05 mm to 2 mm, and the depth is 0.05 mm to 2 mm. The same ink as that contained in the ink containing portion 404a of the refill member 404 is held in a dried state in each of the grooves 408d1 and 408d2.

[0164] 69, the knock member 416 is inserted into the inner cylinder 410 from the rear so that the axial protrusion 410f of the inner cylinder 410 is positioned in the axial groove 432a of the knock member 416. The rotor 412 is inserted into the knock member 416 from the front to a position where the truncated cone portion 424b formed on the base 421 exceeds the locking portion 434b of the knock member 416. The cam portion 410b of the inner cylinder 410 and the cam post 428 of the rotor 412 are aligned along the inner surface of the shaft cylinder 402 and are positioned on the same circle.

[0165] With this configuration, knock member 416 is restricted from rotating with respect to inner cylinder 410, and is movable in the axial direction relative to inner cylinder 410. Furthermore, rotor 412 is rotatable with respect to knock member 416, and is also movable in the axial direction relative to inner cylinder 410 between a position where locking portion 434b of knock member 416 abuts against truncated cone portion 424b of rotor 412 and a position where main body side cam portion 432b of knock member 416 abuts against cam protrusion 426a of rotor 412.

[0166] The main body portion 410a and cam portion 410b of the inner tube 410 are accommodated in the rear end opening 402b of the barrel 402, and the threaded portion of the barrel 402 and the threaded portion 410e of the inner tube 410 are threadedly engaged with each other, thereby attaching the inner tube 410 to the rear end of the barrel 402.

[0167] The rear end of the refill member 404 is inserted into the annular holding portion 430 of the rotor 412 and abuts against the front surface of the annular portion 426. This allows the refill member 404 to be held by the rotor 412 so as to be able to be fed out and pulled back.

[0168] Furthermore, spring member 414 is disposed between refill member 404 and barrel 402. In a contracted state, spring member 414 is sandwiched between step portion 402d of barrel 402 and holding portion 430 of rotor 412. As a result, rotor 412 is biased rearward by spring member 414.

[0169] In the retraction mechanism of the knock-type writing instrument of this embodiment, when a user presses knock member 416 against the biasing force of spring member 414, rotor 412 moves forward and then rotates relative to inner tube 410. This rotation of rotor 412 allows cam pillar 428 of rotor 412 to switch between a state in which it is housed in first notch 418 of inner tube 410 and a state in which it is housed in second notch 420. This allows switching between a state in which brush tip 404b of refill member 404 held by rotor 412 is housed within barrel 402 (brush tip housed state) and a state in which brush tip 404b of refill member 404 protrudes from tip opening 402a of barrel 402 (brush forward extended state).

[0170] Figure 74 is a perspective view showing the rear end portion of the knock-type writing instrument shown in Figure 68. As shown in Figure 74, clip member 408 is made of a colorless, transparent resin, so second display portion 408c formed on clip member 408 is visible from the radially outward direction. Furthermore, knock member 416 is made of a transparent or semi-transparent, visible resin, so first display portion 424c of rotor 412 is visible through knock member 416.

[0171] The first display portion can be formed as follows. First, when molding rotor 412, groove 424d is formed in the portion corresponding to first display portion 424c. Next, ink stored in ink storage portion 404a of refill member 404 is dripped into groove 424d of first display portion 424c. The dripped ink is drawn into groove 424d by capillary action, spreads throughout groove 424d, and is retained within groove 424d. The ink in groove 424d then dries, completing the formation of the ink.

[0172] The second display portion 408c can be formed as follows. First, when molding the clip member 408, the character groove portion 408d1, the connecting groove portion 408d2, and the reservoir portion 408d3 are formed on the inner surface of the clip member 408. Note that the character groove portion 408d1, the connecting groove portion 408d2, and the reservoir portion 408d3 may be cut after the clip member 408 is molded.

[0173] Next, ink is dropped into reservoir 408d3. The dropped ink is drawn into connecting groove 408d2 by capillary action, spreads through connecting groove 408d2 to the entire character groove 408d1, and is retained within character groove 408d1. The ink in character groove 408d1 then dries, forming the mark.

[0174] According to the sixth embodiment, the following effects can be achieved in addition to the effects of the first embodiment. According to the sixth embodiment, the first and second display portions 408c, 424c are provided at positions visible from the outside other than the refill member 404, and therefore have high visibility from the outside. Furthermore, the first and second display portions 408c, 424c are formed by ink being drawn into and held in the groove portions 408d1, 424d by capillary action, and therefore the first and second display portions 408c, 424c can be formed without printing, and the first and second display portions 408c, 424c can be formed during assembly.

[0175] Furthermore, according to the sixth embodiment, the grooves 408d1 and 424d of the first and second display portions 408c and 424c hold ink of the same color as the ink contained in the ink containing portion 404a. Ballpoint pens are provided with indicators that display the color of ink. In contrast, when forming indicators by printing, it is necessary to prepare materials on which multicolored indicators are printed in advance, which makes inventory management time-consuming. In contrast, according to the first embodiment, the first and second indicators 408c and 424c can be manufactured by dripping ink into the grooves 408d1 and 424d during assembly, which allows for reduced inventory even when ink colors are varied.

[0176] Furthermore, according to the sixth embodiment, the clip member 408 that constitutes the first display portion 424c is transparent. According to the present invention having the above configuration, the first display unit 424c can be viewed from a wide range of angles, improving the visibility of the display unit.

[0177] Furthermore, according to the sixth embodiment, writing implement 401 includes barrel 402 that houses refill 404 and clip member 408 that extends along barrel 402, second display portion 408c is formed in clip member 408, and groove 408d1 is formed on the inner surface of clip member 408. According to this embodiment having such a configuration, groove 408d1 formed on the inner surface of clip member 408 can be seen from the outside.

[0178] In addition, in the sixth embodiment, the writing instrument 401 includes a transparent knock member 416 that controls the extension and retraction of the brush tip, and a rotor 412 whose rear end is surrounded by the knock member 416 and that moves the refill member 404 forward and backward, and the first display portion 424c is formed at the rear end of the rotor 412. This allows first display portion 424c at the rear end of rotor 412 to be viewed through knock member 416, and first display portion 424c can be viewed from a wide angle.

[0179] In this embodiment, first display unit 424c is formed on rotor 412, and second display unit 408c is formed on clip member 408, but the present invention is not limited to this. The display units may be provided in any position visible from the outside other than the ink containing portion of refill member 404. The configuration of the display unit of this embodiment can also be adopted in other embodiments. [Explanation of symbols]

[0180] 1. Knock-type writing implement 2 shaft cylinder 2a Tip opening 2b Rear end opening 2c Threaded part 2d stepped section 4 Refill material 4a Ink storage section 4b Tip of the brush 6 Appearance mechanism 8 Clip member 8a Connection 8b Main body 8c Notch 8d protrusion 10 Inner cylinder 10a Main body 10b Cam section 10c Rear end 10d Clip holding part 10d1 Connection 10d2 Main body 10d3 Holding part 10e Threaded part 10f Axial protrusion 12 rotor 14 Spring member 16 Knock member 18 First notch 18a Axial groove 18b Information Department 20 Second notch 20a Slope 20b Edge 21 Base 22 Main body 22a Reduced diameter part 24 Rear end 24a Cylindrical part 24b Cone truncated part 24c Display section 26 Annular part 26a Cam protrusion 26b Rotating cam part 28 Cam pillar 28a Rear end surface 28b Edge 30 Holding part 32 Front 32a Axial groove 32b Main body side cam 32b1 Left protrusion 32b2 Central protrusion 32b3 Right side protrusion 34 Middle section 34b Locking part 36 rear 101 Knock-type writing implement 102 Shaft cylinder 102a Tip opening 102b Rear end opening 102c Threaded part 106 Appearance mechanism 108 Clip member 108a Connection 108a1 Middle convex part 108a2 Axial convex part 108b Main body 110 Inner cylinder 110a Main body 110b Cam part 110c rear end 110c1 Front large diameter part 110c2 Intermediate small diameter section 110c3 Rear large diameter section 110c4 Notch 110e Threaded part 110f Main body cam 110f0 side 110f1 Rear slope 110f2 Stepped section 110f3 Front slope 110f4 flat part 110f5 Cam protrusion 110g reduced diameter part 110g1 Notch 112 Rotor 114 Spring member 116 Knock parts 116a Through hole 116b Locking part 118 First notch 118a Axial groove 118b Information Department 120 Second notch 120a Slope 120b Edge 121 Base 122 Main body 122b Rotating cam part 122b1 Slope section 124 Rear end 124a Annular recess 124b Cone truncated part 124c Cylinder 126 Annular part 128 Cam pillar 130 Holding part 132 Front 136 rear 151 Knock-type writing implement 154 Spring member 201 Knock-type writing implement 202 Shaft cylinder 202a Tip opening 202b Rear end opening 202c Threaded part 202d Main body cam 202f convex part 202f1 Slope section 202f2 Edge 202f3 Circumferential surface section 206 Appearance mechanism 208 Clip member 208a Connection 208b Shaft 208c Notch 208d Protrusion 208e flat area 210 Inner cylinder 210 Inner cylinder 210a Main body 210b Cam part 210c rear end 210d Clip holder 210d1 Connection 210d2 Main body 210d3 Holding part 210e Threaded part 210g reduced diameter part 212 Rotor 214 Spring member 216 Knock parts 216a Through hole 216b Locking part 218 First notch 218a Axial groove 218b Information Department 220 Second notch 220a Slope 220b Edge 221 Base 222 Main body 224 Rear end 224a Middle cylindrical section 224b Annular recess 224c Cone truncated part 224d Cylinder 226 Annular part 228 Cam pillar 230 Holding part 230a Rotating cam part 230a0 convex part 230a1 Edge 230a2 Slope section 230a3 flat area 232 Front 236 rear 301 Knock-type writing implement 302 Shaft cylinder 302a Tip opening 302b Rear end opening 302c threaded part 302d Stepped section 302e Notch 302f through hole 304 Refill material 304b Brush tip 306 Appearance mechanism 308 Clip member 308a Connection 308a1 base 308a2 Tip 308b Main body 308c Notch 308d Side edge 310 Inner cylinder 310a Main body 310b Cam part 310c rear end 310d Clip holder 310d1 Connection 310d2 Main body 310d3 First holding part 310d3a base 310d3b Widened section 310d4 Second holding part 310d5 Protrusion 310e threaded part 310f Axial protrusion 312 Rotor 314 Spring member 316 Knock parts 318 First notch 318a Axial groove 318b Information Department 320 Second notch 321 Base 322 Main body 322a Reduced diameter section 324 Rear end 324a Cylinder 324b Cone truncated part 324c display 326 Annular part 326a Cam protrusion 326b Rotating cam part 328 Cam pillar 330 Holding part 332 front 332a Axial groove 332b Main body side cam 332b1 Protrusion 332b2 Protrusion 332b3 Protrusion 334 Middle section 334b Locking part 336 rear 401 Knock-type writing implement 402 Shaft cylinder 402a Tip opening 402b Rear end opening 402d Stepped section 404 Refill material 404a Ink storage section 404b Tip part 406 Appearance mechanism 408 Clip member 408a Connection 408b Main body 408c Second display unit 408d1 Character groove 408d2 Connection groove 408d3 Tamabe 410 Inner cylinder 410a Main body 410b Cam part 410c rear end 410d Clip holder 410d1 aperture 410e threaded part 410f Axial protrusion 412 Rotor 414 Spring member 416 Knock parts 418 First notch 418a Axial groove 418b Information Department 420 Second notch 421 Base 422 Main body 422a Reduced diameter section 424 Rear end 424a Cylindrical part 424b Cone truncated part 424c First display unit 424d Groove 424d Groove 426 Annular part 426a Cam protrusion 426b Rotating cam part 428 Cam pillar 428a Rear end surface 430 Holding part 432 Front 432a Axial groove 432b Main body side cam 432b1 Protrusion 432b2 Protrusion 432b3 Projection 434 Middle section 434b Locking part 436 rear

Claims

[Claim 1] A knock-type writing instrument comprising: a barrel having a front end opening and a rear end opening; a writing member housed in the barrel; and a retraction mechanism for causing the front end of the writing member to protrude and retract from the front end opening of the barrel, The retractable mechanism is an inner cylinder attached to a rear end portion of the barrel and having a cam portion extending along an inner surface of the barrel; a rotor having a base, a plurality of cam posts extending axially along the inner surface of the barrel from the base toward the tip, and a holding portion connected to the tip of the cam posts and holding the rear end of the writing element inside, the rotor having the base disposed within the inner barrel; a spring that biases the rotor toward the rear end; a knock member that is disposed in the inner cylinder and that is capable of pushing the rotor toward the tip side by being pushed toward the tip side, The knock member has an internal space that is open at least to the front, At least a portion of the base of the rotor is located within the internal space of the knock member, the knock member holds a base of the rotor, The knock member is inserted into the inner cylinder from the rear so that the axial protrusion of the inner cylinder is positioned within the axial groove of the knock member, and the rotor is inserted into the knock member from the front until the truncated cone portion formed at the base exceeds the locking portion of the knock member, and the cam portion of the inner cylinder and the cam post of the rotor are aligned along the inner surface of the shaft cylinder and positioned on the same circle, The inner cylinder, the knock member, and the rotor are integrally assembled. A knock-type writing instrument characterized by:

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