Knock type writing utensil

Abstract

To provide a knock type writing utensil in which jolting of a knock member in the radial direction with respect to a rotator is suppressed.SOLUTION: A knock-type writing utensil 1 comprises: a barrel 2, a knock member 30 which is formed in a cylindrical shape and has a cam surface; and a rotator 40 disposed in front of the knock member and having a cam receiving surface which cooperates with the cam surface of the knock member and an insertion part 41 which is insertable into the knock member. The knock-type writing utensil has a first restriction part 36 formed on the inner surface of the knock member, and a second restriction part 47 formed on the outer surface of the insertion part of the rotator. When the cam surface and the cam receiving surface cooperate with each other by the knock operation to rotate the rotator with respect to the knock member and thereby the knock-type writing utensil is in a writing state, the first restriction part 36 and the second restriction part 47 are aligned in the radial direction to restrict the movement of the knock member in the radial direction with respect to the rotator. The first restriction part 36 and the second restriction part 47 are not aligned in the radial direction during the knock operation.SELECTED DRAWING: Figure 18

Description

[Technical field]

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

[0002] Generally, a knock-type writing instrument has a knock member disposed at the rear end of the barrel, a rotor disposed in front of the knock member, a spring that urges the refill, which is the writing body, backward, and an outer cam, which is a cam protrusion, disposed on the inner surface of the barrel. In the knock-type writing instrument, a knock operation is performed to press the knock member forward against the urging force of the spring, thereby switching between a writing state in which the writing part, which is the pen tip, protrudes from the tip of the barrel and a non-writing state in which the writing part is retracted into the barrel. Specifically, the knock operation causes the knock member to move forward together with the rotor and rotate the rotor by a predetermined rotation angle. Depending on the rotation of the rotor caused by the knock operation, the rotor engages or disengages with the outer cam in the barrel, thereby switching the knock-type writing instrument between a writing state and a non-writing state.

[0003] When the knock-type writing instrument is in a writing state, the rotor, which is biased backward by the spring, engages with the outer cam and is fixed. On the other hand, the knock member is not biased by the spring and is not restricted by other members. Therefore, the knock member is slightly movable in the radial and axial directions of the central axis of the knock-type writing instrument, which causes it to rattle. Therefore, there is a risk that the knock member will hit the rotor or the barrel during writing operations, etc., resulting in unpleasant noise and vibration for the user.

[0004] To solve the problem of rattling of the knock member, a knock type writing instrument is known, as described in Patent Document 1. In the knock type writing instrument described in Patent Document 1, a locking protrusion provided on a rotor (rotating cam) and a locking step provided on a knock member (fixed cam) are locked in the axial direction to reduce rattling. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-305990 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the knock-type writing instrument described in Patent Document 1, as described in Patent Document 1 in the first place, slight axial wobble of the knock member is permitted, and furthermore, no consideration is given to radial wobble of the knock member.

[0007] An object of the present invention is to provide a knock-type writing instrument in which radial rattle of a knock member relative to a rotor is suppressed. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a knock-type writing instrument including a barrel, a knock member formed cylindrically and having a cam surface, and a rotor arranged in front of the knock member, the rotor having a cam receiving surface that cooperates with the cam surface of the knock member and an insertion portion that can be inserted into the knock member, wherein a first regulating portion is formed on the inner surface of the knock member and a second regulating portion is formed on the outer surface of the insertion portion of the rotor, and when a knock operation causes the cam surface and the cam receiving surface to cooperate to rotate the rotor relative to the knock member and the knock-type writing instrument is in a writing state, the first regulating portion and the second regulating portion are configured to be aligned in the radial direction to regulate the radial movement of the knock member relative to the rotor, and during a knock operation, the first regulating portion and the second regulating portion are configured not to be aligned in the radial direction.

[0009] The first and second regulating parts may be configured to come into contact with each other when the first and second regulating parts are aligned in the radial direction, and the knock member and the rotor may be locked in the axial direction. The first and second regulating parts may be protrusions or ribs extending in the longitudinal direction. The first regulating part may be provided according to the rotation angle of the rotor by one knock operation. The refill may further include a ballpoint pen tip having a ball at its tip, and a buffer part penetrating from the outside to the inside of the barrel may be provided, and the forward movement of the refill may be regulated by abutment with the buffer part, and the buffer part may be made of a viscoelastic material. A grip part may be provided on the outer surface of the barrel, and the buffer part may be made of a part of the grip part. The screw may be configured to have a male threaded member having a male threaded portion, and a tubular female threaded member having a female threaded portion and capable of being screwed into the male threaded member, wherein the male threaded portion has a first locking portion and the female threaded portion has a second locking portion, and when the male threaded member and the female threaded member are screwed together, the first locking portion and the second locking portion climb over each other, so that when the male threaded member and the female threaded member are unscrewed from each other, the first locking portion and the second locking portion lock together. Effect of the Invention

[0010] According to the aspects of the present invention, a common effect is achieved in that a knock-type writing instrument is provided in which radial rattle of the knock member relative to the rotor is suppressed. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a first knock-type writing instrument in a non-writing state. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the knock-type writing instrument of FIG. [Diagram 3] FIG. 3 is an exploded perspective view of the knock-type writing instrument of FIG. [Figure 4] 4 is a perspective view of the front barrel of the knock-type writing instrument of FIG. 1. FIG. [Diagram 5] 5 is a perspective view of the rear barrel of the knock-type writing instrument of FIG. 1. FIG. [Figure 6] FIG. 6 is a vertical cross-sectional view of the rear axle of FIG. [Figure 7] 7 is a perspective view of the inner barrel of the knock-type writing instrument of FIG. [Figure 8] FIG. 8 is a side view of the inner cylinder of FIG. [Figure 9] FIG. 9 is a vertical cross-sectional view of the inner cylinder of FIG. [Figure 10] 10 is a perspective view of a knock member of the knock type writing instrument of FIG. [Figure 11] FIG. 11 is a vertical cross-sectional view of the knock member of FIG. [Figure 12] FIG. 12 is a perspective view of the rotor of the knock-type writing instrument of FIG. [Figure 13] FIG. 13 is a partial perspective view illustrating the fitting of the front and rear barrels of the knock-type writing instrument of FIG. [Figure 14] FIG. 14 is a schematic diagram showing switching of the knock type writing instrument of FIG. 1 from a non-writing state to a writing state. [Figure 15] FIG. 15 is a schematic diagram showing switching of the knock type writing instrument of FIG. 1 from a writing state to a non-writing state. [Figure 16] 16 is a cross-sectional view showing an assembly of the knock member and the rotor of the knock type writing instrument of FIG. [Figure 17] FIG. 17 is a cross-sectional view taken along the line AA in FIG. 16, which corresponds to a knock-type writing instrument during a knock operation. [Figure 18] FIG. 18 is a cross-sectional view taken along the line AA in FIG. 16, which corresponds to the knock-type writing implement in a writing state. [Figure 19] FIG. 19 is a perspective view of the second knock type writing instrument in a non-writing state. [Figure 20] FIG. 20 is a side view of the knock-type writing instrument of FIG. [Figure 21] FIG. 21 is a vertical cross-sectional view of the knock-type writing instrument of FIG. [Figure 22] FIG. 22 is an exploded perspective view of the knock-type writing instrument of FIG. [Diagram 23] 23 is a vertical cross-sectional view of the front barrel of the knock-type writing instrument of FIG. [Figure 24] 24 is a perspective view of the rear barrel of the knock-type writing instrument of FIG. 19. FIG. [Diagram 25] FIG. 25 is a vertical cross-sectional view of the rear axle of FIG. [Figure 26] 26 is a perspective view of the inner barrel of the knock-type writing instrument of FIG. 19. FIG. [Figure 27] FIG. 27 is a side view of the inner cylinder of FIG. [Figure 28] FIG. 28 is a vertical cross-sectional view of the inner cylinder of FIG. [Figure 29] 29 is a perspective view of a clip member of the knock-type writing instrument of FIG. 19. FIG. [Diagram 30] 30 is a vertical sectional view illustrating the attachment of the clip member of the knock-type writing implement of FIG. [Diagram 31] 31 is a vertical cross-sectional view of the front end portion of the knock-type writing instrument of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Corresponding components are designated by common reference numerals throughout the drawings.

[0013] Fig. 1 is a perspective view of a first knock type writing instrument 1 in a non-writing state, Fig. 2 is a vertical cross-sectional view of the knock type writing instrument 1 of Fig. 1, and Fig. 3 is an exploded perspective view of the knock type writing instrument 1 of Fig. 1. The knock type writing instrument 1 has a barrel 2 equipped with a front barrel 3 and a rear barrel 4 screwed onto the outer surface of the rear end of the front barrel 3, an inner barrel 5 inserted inside the rear end of the barrel 2, a refill 6 which is a writing body disposed inside the barrel 2 and equipped with a writing portion 6a at one end, and a spring 7 which biases the refill 6 rearward.

[0014] In this specification, in the axial direction of the knock type writing instrument 1, the side of the writing part 6a is defined as the "front" side, and the side opposite the writing part 6a is defined as the "rear" side. In the description of each component, the "front" side and the "rear" side are defined based on the state in which the knock type writing instrument 1 is assembled. In the knock type writing instrument 1, the state in which the writing part 6a protrudes from the barrel 2 by a knock operation is referred to as the writing state (not shown), and the state in which the writing part 6a is retracted into the barrel 2 is referred to as the non-writing state (FIGS. 1 and 2). The barrel 2 may be referred to including the inner barrel 5.

[0015] An outer cam 20, which is a cam protrusion, is formed on the inner surface of the barrel 2, i.e., the inner surface of the inner barrel 5. A knock member 30 is disposed inside the rear end of the barrel 2, i.e., inside the rear end of the inner barrel 5. A part of the knock member 30 protrudes rearward from the rear end of the inner barrel 5. A rotor 40 is disposed in front of the knock member 30. The rear end face of the refill 6, which is biased rearward by the spring 7, abuts against the front end face of the rotor 40. Therefore, the rotor 40 is always biased rearward by the spring 7 via the refill 6. A clip holding portion 50 is provided on the side of the barrel 2. The clip holding portion 50 is composed of a first holding portion 50a provided on the front barrel 3 and a second holding portion 50b provided on the rear barrel 4. The clip member 60 is attached to the barrel 2 by the clip holding portion 50.

[0016] 3, the clip member 60 is formed by bending a single metal wire such as stainless steel into a long, thin ring shape. Both ends of the wire of the clip member 60, i.e., a first end 61 and a second end 62, are disposed on one side closer to the rear than the center in the longitudinal direction. The first end 61 is disposed forward of the second end 62. The first end 61 and the second end 62 are bent so as to be perpendicular to the longitudinal direction of the clip member 60.

[0017] FIG. 4 is a perspective view of the front barrel 3 of the knock-type writing instrument 1 of FIG. 1. The front barrel 3 is a cylindrical member. The outer surface of the rear end of the front barrel 3 is provided with a male screw portion 3a that screws into the rear barrel 4. A first locking portion 8 is provided at the start point 3b of the male screw portion 3a, that is, at the end of the helical track of the male screw portion 3a extended from the rear end toward the rear. The first locking portion 8 is a spherical protrusion having approximately the same height as the thread of the male screw portion 3a. The outer surface of the front barrel 3 from the front of the male screw portion 3a to the front end opening from which the writing portion 6a protrudes is covered with a grip portion 10 formed by two-color molding during the manufacture of the front barrel 3. The front barrel 3 is formed of a hard plastic such as polycarbonate, ABS, PET, or PBT, and the grip portion 10 is formed of a viscoelastic material such as PTFE, polyethylene, or polypropylene. When the knock-type writing instrument 1 is in an assembled state, the entire exposed outer surface of the front barrel 3 is covered by the grip portion 10, so that the user can grip any part of the front barrel 3 when writing.

[0018] FIG. 5 is a perspective view of the rear barrel 4 of the knock-type writing instrument 1 of FIG. 1, and FIG. 6 is a vertical cross-sectional view of the rear barrel 4 of FIG. 5. The rear barrel 4 is a cylindrical member. An internal thread 4a that can be screwed with the external thread 3a of the front barrel 3 is provided on the inner surface of the front end of the rear barrel 4. Two rectangular reduced diameter portions 4b that protrude radially inward are formed behind the internal thread 4a. The reduced diameter portions 4b are protrusions that protrude at a uniform height from the inner surface of the rear barrel 4. The two reduced diameter portions 4b are disposed at positions facing each other across the central axis of the rear barrel 4. An inclined surface 4c is provided at the rear end of the reduced diameter portion 4b.

[0019] A first retaining portion 50a is provided on the side surface of the rear end of the rear axle 4. The first retaining portion 50a and each of the two reduced diameter portions 4b are disposed at positions shifted by 90 degrees in the rotation direction around the central axis. The first retaining portion 50a has a notch portion 51 extending forward from the rear end opening of the rear axle 4 and formed in a substantially rectangular shape, a pair of side walls 52 formed on both sides in the circumferential direction of the notch portion 51, a first support portion 53 provided at the front end portion of the notch portion 51, and a first front wall 54 provided in front of the first support portion 53. The pair of side walls 52, the first support portion 53, and the first front wall 54 are protrusions protruding in the same direction from the outer surface of the rear axle 4, and each of the tip surfaces is formed flat. As shown in FIG. 6, the heights of the protrusions are formed lower in the order of the pair of side walls 52, the first front wall 54, and the first support portion 53. The pair of side walls 52 are provided with outer surfaces that are cylindrical relative to each other. The front surface of the first front wall 54 is provided with a cylindrical surface. As a result, the pair of side walls 52 and the first front wall 54 are formed so as to be inscribed inside a cylinder having a central axis perpendicular to the central axis of the rear body 4.

[0020] FIG. 7 is a perspective view of the inner tube 5 of the knock-type writing instrument 1 of FIG. 1, FIG. 8 is a side view of the inner tube 5 of FIG. 7, and FIG. 9 is a vertical cross-sectional view of the inner tube 5 of FIG. The inner tube 5 is a cylindrical member. Two rectangular recesses 5a are formed on the outer surface of the front of the inner tube 5. The recesses 5a are recesses of uniform depth from the outer surface of the inner tube 5. The two recesses 5a are arranged at positions facing each other across the central axis of the inner tube 5. The rectangular recess 5a has a U-shaped hole 5b formed therein, which is substantially U-shaped and consists of a through hole along the rear edge and two through holes extending forward from each of both ends of the through hole. The U-hole 5b defines an elastic deformation portion 5c inside the recess 5a. The elastic deformation portion 5c defined by the U-hole 5b is a cantilever beam extending rearward. A protrusion 5d protruding radially outward is formed on the outer surface of each of the elastic deformation portions 5c. The convex portion 5d is a spherical protrusion. The circumscribing circle of the two convex portions 5d is formed to be slightly larger than the diameter of the inscribing circle of the two reduced diameter portions 4b of the rear body 4 with respect to the central axis.

[0021] A second holding portion 50b is provided on the side surface near the rear end of the inner tube 5. The second holding portion 50b and each of the two elastic deformation portions 5c are disposed at positions shifted by 90 degrees in the rotation direction around the central axis. The second holding portion 50b has a base portion 55 protruding radially outward from the side surface of the inner tube 5, and a disk-shaped cover portion 56 provided at the tip of the base portion 55. The central axis of the cover portion 56 is perpendicular to the central axis of the inner tube 5. A second front wall 57 extending radially inward is provided at the front end of the cover portion 56. Furthermore, a second support portion 58 extending radially inward from the second front wall 57 is provided at the rear portion of the second front wall 57. A first recess 59a is provided between the base portion 55 and the second support portion 58. The first recess 59a opens radially inward and penetrates laterally. A second recess 59b is provided near the base portion 55 on the opposite side of the first recess 59a with respect to the base portion 55. The second recess 59b is open toward the rear and penetrates in the same direction as the first recess 59a. The first recess 59a and the second recess 59b are disposed at equal distances from the central axis of the inner cylinder 5.

[0022] Four outer cams 20, which are cam protrusions, are provided at equal intervals along the circumferential direction on the inner surface of the rear end of the inner cylinder 5. Four first guide grooves 21 extending in the front-rear direction are defined by adjacent outer cams 20. Each of the outer cams 20 is composed of a first protrusion 22 and a second protrusion 23 extending in the front-rear direction and arranged continuously in the circumferential direction. The first protrusion 22 and the second protrusion 23 have the same shape. The front end surfaces of the first protrusion 22 and the second protrusion 23 are inclined surfaces inclined at the same angle with respect to the circumferential direction. A second guide groove 24 extending in the front-rear direction is formed between the first protrusion 22 and the second protrusion 23. The width of the first guide groove 21 in the circumferential direction is larger than the width of the second guide groove 24 in the circumferential direction. The depth of the first guide groove 21 and the depth of the second guide groove 24 are the same. In the outer cam 20, a regulating surface 25 is provided at the rear ends of the first guide groove 21 and the second guide groove 24.

[0023] FIG. 10 is a vertical cross-sectional view of the knock member 30 of the knock-type writing instrument 1 of FIG. 1, and FIG. 11 is a vertical cross-sectional view of the knock member 30 of FIG. 10. The knock member 30 is a cylindrical member formed in a gentle tapered shape toward the rear. Eight locking protrusions 31 are provided at equal intervals along the circumferential direction on the outer surface of the front side of the knock member 30. Each of the locking protrusions 31 is configured to be disposed in the first guide groove 21 between the adjacent outer cams 20, or in the second guide groove 24 between the first protrusion 22 and the second protrusion 23. Each of the locking protrusions 31 is configured to move in the front-rear direction in the first guide groove 21 or the second guide groove 24 by a knock operation. A cam surface 32 is formed on the front end surface of the knock member 30. The cam surface 32 has eight peaks 33 and valleys 34. A slope is formed between the peaks 33 and the valleys 34. A circular crown 35 is attached to the rear end of the knock member 30.

[0024] Eight first restricting portions 36, which are elongated projections extending rearward from the vicinity of the front end, are provided on the inner surface of the knock member 30 at equal intervals along the circumferential direction. The first restricting portions 36 have a shape like a cut-out side of a cylinder having a central axis parallel to the central axis of the knock member 30. Therefore, the cross section of the first restricting portions 36, i.e., a cross section perpendicular to the central axis, has an arc-shaped contour. In addition, since the side surface of the knock member 30 is formed with approximately the same thickness, the inner surface of the knock member 30 is formed in a gentle taper toward the rear in accordance with the outer shape of the knock member 30. Therefore, the protruding first restricting portions 36 are formed so that their height gradually decreases toward the rear. The front end of the first restricting portions 36 is formed with a curved surface portion 36a formed in a spherical shape. The inner surface of the knock member 30 is provided with an annular protrusion 37 that is annular around the central axis so as to connect each of the first restricting portions 36.

[0025] FIG. 12 is a perspective view of the rotor 40 of the knock-type writing instrument 1 of FIG. 1. The rotor 40 is a cylindrical member. The rotor 40 is composed of an insertion portion 41 that is inserted into the inside of the knock member 30 from the front end portion and used for centering, and a large diameter portion 42 that is disposed in front of the insertion portion 41 and has a larger diameter. The insertion portion 41 is formed in a gentle taper toward the rear. A cam receiving surface 43 that cooperates with the cam surface 32 of the knock member 30 and has a complementary shape is formed on the annular rear end surface of the large diameter portion 42. The cam receiving surface 43 has eight peaks 44 and valleys 45, similar to the cam surface 32 of the knock member 30. Slopes are formed between the peaks 44 and valleys 45. Four inner cams 46, which are protrusions extending in the front-rear direction, are provided at equal intervals along the circumferential direction on the outer surface of the large diameter portion 42. The width of the inner cam 46 in the circumferential direction is smaller than the width of the first guide groove 21 and larger than the width of the second guide groove 24.

[0026] The outer surface of the insertion portion 41 is provided with two elongated protruding second restricting portions 47 extending forward from the rear end portion. The two second restricting portions 47 are arranged at positions facing each other across the central axis of the rotor 40. The cross section of the second restricting portion 47, i.e., a cross section perpendicular to the central axis of the rotor 40, is a substantially isosceles trapezoid. A flat top portion 47a is formed in the longitudinal direction of the second restricting portion 47 by a portion corresponding to the upper base of the trapezoid. The top portion 47a extends substantially parallel to the central axis of the rotor 40. The insertion portion 41 is also formed in a gentle taper toward the rear. Therefore, the protruding second restricting portion 47 is formed so that its height gradually increases toward the rear. The rear end portion of the second restricting portion 47 is formed with a chamfered portion 47b that is as if it were cut off obliquely.

[0027] The assembly of the knock type writing instrument 1 will be described mainly with reference to FIG. 3. First, the spring 7 is inserted from the rear end opening of the front shaft 3, and then the refill 6 is inserted. Meanwhile, the knock member 30 is inserted from the front end opening of the inner tube 5, and then the rotor 40 is inserted. Also, the second end 62 of the clip member 60 is pressed from the rear side against the second recess 59b of the second holding portion 50b of the inner tube 5 to be fitted. That is, the gap of the second recess 59b that opens to the rear side is formed slightly narrower than the outer diameter of the metal wire of the clip member 60. Therefore, by pressing the second end 62 against the second recess 59b, the second end 62 snaps into the second recess 59b. Next, the first end 61 of the clip member 60 is placed in the first recess 59a of the second holding portion 50b of the inner tube 5. The gap of the first recess 59a that opens radially inward is formed larger than the outer diameter of the metal wire of the clip member 60. Therefore, the first end 61 can be easily disposed in the first recess 59a by elastically deforming the clip member 60. As a result, the clip member 60 is attached to the second holding portion 50b so as to surround the base portion 55.

[0028] The inner tube 5, into which the knock member 30 and the rotor 40 are inserted and to which the clip member 60 is attached, is inserted from the rear end opening of the rear axle 4 and press-fitted, thereby attaching the inner tube 5 to the rear axle 4. At this time, the inner tube 5 is aligned in the rotational direction so that the base portion 55 of the second retaining portion 50b of the inner tube 5 is received in the cutout portion 51 of the rear axle 4. The outer diameter of the front end of the inner tube 5 is slightly larger than the diameter of the inscribed circle of the reduced diameter portion 4b of the rear axle 4. However, since an inclined surface 4c is formed at the rear end of the reduced diameter portion 4b of the rear axle 4, the front end edge of the inner tube 5 can overcome the reduced diameter portion 4b and the inner tube 5 can be inserted all the way.

[0029] When the inner cylinder 5 is attached to the rear axle 4, the reduced diameter portion 4b of the rear axle 4 is housed in the recess 5a of the inner cylinder 5. Even if a force acts on the inner cylinder 5 to pull it out of the rear axle 4, the front end edge 4d of the reduced diameter portion 4b of the rear axle 4 engages with the step portion 5e in front of the recess 5a of the inner cylinder 5, preventing the inner cylinder 5 from being unintentionally removed from the rear axle 4. Furthermore, the convex portion 5d of the elastically deforming portion 5c abuts against the reduced diameter portion 4b of the rear axle 4, thereby elastically deforming the elastically deforming portion 5c so as to be curved radially inward. In this state, when the front end opening of the rear axle 4 is directed vertically downward, the knock member 30 and the rotor 40 move downward due to gravity, but the front end edge or front end face of the rotor 40 engages with the rear end edge 5f or rear end face of the elastically deforming portion 5c. Therefore, even if the front end opening of rear shaft 4 is removed from front shaft 3 when replacing the refill, etc., and faced vertically downward, rotor 40 will not fall off rear shaft 4 and inner cylinder 5.

[0030] When the base portion 55 of the second holding portion 50b is inserted deep into the cutout portion 51 of the rear axle 4, the first holding portion 50a and the second holding portion 50b are fitted together to form the clip holding portion 50 integrally. That is, the base portion 55 of the second holding portion 50b and the clip member 60 attached to the base portion 55 are disposed between a pair of side walls 52 of the first holding portion 50a. Also, the first support portion 53 and the first front wall 54 of the first holding portion 50a are abutted complementarily with the second support portion 58 and the second front wall 57 of the second holding portion 50b, respectively, as shown in FIG. 2, and the first end portion 61 of the clip member 60 is surrounded. In other words, the first end portion 61, which is the mounting portion of the clip member 60, is radially sandwiched between the first holding portion 50a and the second holding portion 50b. As a result, the clip member 60 is attached to the axle tube 2 by the clip holding portion 50.

[0031] The clip holding portion 50 is formed into a generally substantially cylindrical shape by a pair of side walls 52 and a first front wall 54 of the first holding portion 50a and a cover portion 56 and a second front wall 57 of the second holding portion 50b. The clip member 60 is arranged so as to penetrate the substantially cylindrical clip holding portion 50 from the side along the central axis of the knock-type writing instrument 1. Therefore, the attachment portion of the clip member 60, i.e., the first end 61 and the second end 62, are substantially concealed by the clip holding portion 50. Therefore, the attachment structure, i.e., the portion of the clip member 60 involved in attachment, cannot be seen from the outside, and therefore the design of the attachment structure of the clip member 60 can be improved. Furthermore, in the knock-type writing instrument 1, the clip member 60 can be easily disassembled by removing the inner tube 5 from the rear barrel 4.

[0032] Fig. 13 is a partial perspective view illustrating the fitting of the front barrel 3 and the rear barrel 4 of the knock-type writing instrument 1 of Fig. 1. After the inner cylinder 5 is attached to the rear barrel 4, the rear barrel 4 is screwed onto the front barrel 3 into which the refill 6 and the spring 7 have been inserted. As described above, the first locking portion 8 is provided on the outer surface of the rear end portion of the front barrel 3, while the second locking portion 9 is provided on the inner surface of the rear barrel 4, as shown in Fig. 13. The second locking portion 9 is a protrusion provided near the end point of the female thread portion 4a, and is formed at approximately the same height as the threads of the female thread portion 4a and so as to close the valleys of the female thread portion 4a.

[0033] The first locking portion 8 of the front barrel 3 and the second locking portion 9 of the rear barrel 4 are provided so as to climb over each other when the front barrel 3 and the rear barrel 4 are completely screwed together. Even if a rotational force acts in a direction that disengages the front barrel 3 and the rear barrel 4 due to vibrations or the like when writing with the knock-type writing instrument 1, the first locking portion 8 and the second locking portion 9 lock together, preventing unintended disengagement. The first locking portion 8 and the second locking portion 9 may be projections of any shape and arranged in any position, so long as they climb over each other and lock together when the front barrel 3 and the rear barrel 4 are screwed together.

[0034] In addition, as a result of being in a screwed state for a long period of time, the threads of the male thread portion 3a and the female thread portion 4a may be deformed by creep, and the amount of tightening that can be performed may become larger than expected. In this case, if the front axle 3 is further screwed to the rear axle 4, the start point 3b of the male thread portion 3a of the front axle 3 may come into contact with the second locking portion 9 of the rear axle 4. In order to prevent the male thread portion 3a of the front axle 3 from coming into contact with the second locking portion 9 of the rear axle 4, when the front axle 3 and the rear axle 4 are completely screwed together before creep occurs, the start point 3b of the male thread portion 3a of the front axle 3 is spaced apart from the second locking portion 9 of the rear axle 4 by a predetermined angle, in other words, the start point 3b of the male thread portion 3a of the front axle 3 is spaced apart from the first locking portion 8 by a predetermined angle. The predetermined angle between the start point 3b of the male thread portion 3a of the front axle 3 and the first locking portion 8 is, for example, 90 degrees.

[0035] FIG. 14 is a schematic diagram showing the switching of the knock-type writing instrument 1 of FIG. 1 from the non-writing state to the writing state. That is, FIG. 14 is a schematic diagram showing the positional relationship between the outer cam 20, the knock member 30, and the rotor 40, and shows the positions of the locking protrusion 31 of the knock member 30 and the inner cam 46 of the rotor 40 with respect to the outer cam 20 developed in the circumferential direction. In the figure, the lower side is the front of the knock-type writing instrument 1, and the upper side is the rear of the knock-type writing instrument 1. For convenience, the shapes of the regulating surface 25 provided at the rear ends of the first guide groove 21 and the second guide groove 24 and the shape of the locking protrusion 31 of the knock member 30 are drawn in a simplified manner. The rotor 40 is given a rotational force by the cooperation of the cam surface 32 of the knock member 30 and the cam receiving surface 43 of the rotor 40, and rotates around the central axis. Therefore, the rotor 40 moves from right to left in FIG. 14 with each knock operation.

[0036] Fig. 14(a) is a schematic diagram showing the non-writing state of the knock-type writing instrument 1. At this time, the inner cam 46 of the rotor 40, which is urged backward by the spring 7 via the refill 6, is disposed in the first guide groove 21 between the outer cams 20. Therefore, in this state, the writing part 6a is sunk into the barrel 2. The locking protrusion 31 of the knock member 30 is disposed in the first guide groove 21 or the second guide groove 24. The cam surface 32 and the cam receiving surface 43 are disposed out of phase with each other.

[0037] 14(a), a knock operation is performed to press the knock member 30 forward against the biasing force of the spring 7, thereby moving the knock member 30 and the rotor 40 forward. At this time, the locking protrusion 31 of the knock member 30 and the inner cam 46 of the rotor 40 move forward in the first guide groove 21. In addition, the knock member 30 and the rotor 40 receive circumferential force components in opposite directions via the inclined surfaces of the cam surface 32 and the cam receiving surface 43, but the rotation of the rotor 40 is restricted by the abutment of the locking protrusion 31 arranged in the second guide groove 24 with the side surfaces of the first protrusion 22 and the second protrusion 23 of the outer cam 20.

[0038] When the knock member 30 and the rotor 40 move further forward, the rear end of the inner cam 46 passes over the front end of the outer cam 20 in the front-rear direction, i.e., the first protrusion 22 (FIG. 14(b)). At this time, the restriction of the rotation of the rotor 40 by the outer cam 20 is released, and the cam surface 32 and the cam receiving surface 43 coincide with each other.

[0039] When the pressure of the knock member 30 is released from the state where the cam surface 32 and the cam receiving surface 43 are aligned, the knock member 30 and the rotor 40 move backward by the biasing force of the spring 7. At this time, the rotor 40 receives a component force from the inclined surface of the outer cam 20 and rotates around the central axis. That is, the inner cam 46 of the rotor 40 moves along the inclined surface of the outer cam 20 until it abuts against the front end side surface of the second protrusion 23, and the rotation of the rotor 40 stops. Since the width of the inner cam 46 is smaller than the width of the first guide groove 21 and larger than the width of the second guide groove 24, the inner cam 46 cannot enter the second guide groove 24. Therefore, the inner cam 46 engages with the front end surface of the first protrusion 22, and the backward movement of the rotor 40 is restricted (FIG. 14(c)). As a result, the writing part 6a of the refill 6 arranged in front of the rotor 40 protrudes from the barrel 2, and the knock-type writing instrument 1 enters a writing state.

[0040] Fig. 15 is a schematic diagram showing switching from a writing state to a non-writing state of the knock-type writing instrument 1 of Fig. 1. Fig. 15 shows the positional relationship between the outer cam 20, the knock member 30, and the rotor 40 in the same manner as Fig. 14.

[0041] FIG. 15(a) is a schematic diagram showing the writing state of the knock-type writing instrument 1, and is the same schematic diagram as FIG. 14(c). From the state of FIG. 15(a), a knock operation is performed to press the knock member 30 forward against the biasing force of the spring 7, thereby moving the knock member 30 and the rotor 40 forward. At this time, the locking protrusion 31 of the knock member 30 and the inner cam 46 of the rotor 40 move forward in the first guide groove 21. In addition, the knock member 30 and the rotor 40 receive circumferential force components in opposite directions via the inclined surfaces of the cam surface 32 and the cam receiving surface 43, but the rotation of the rotor 40 is restricted by the abutment of the locking protrusion 31 arranged in the second guide groove 24 with the side surfaces of the first protrusion 22 and the second protrusion 23 of the outer cam 20.

[0042] When the knock member 30 and the rotor 40 move further forward, the rear end of the inner cam 46 passes over the front end of the outer cam 20 in the front-rear direction, i.e., the second protrusion 23 (FIG. 15(b)). At this time, the restriction of the rotation of the rotor 40 by the outer cam 20 is released, and the cam surface 32 and the cam receiving surface 43 coincide with each other.

[0043] When the pressure on the knock member 30 is released from the state where the cam surface 32 and the cam receiving surface 43 are aligned, the knock member 30 and the rotor 40 move backward by the biasing force of the spring 7. At this time, the rotor 40 receives a component force from the inclined surface of the outer cam 20 and rotates around the central axis. That is, the inner cam 46 of the rotor 40 enters the first guide groove 21 from the inclined surface of the outer cam 20 and moves backward, so that the knock member 30 and the rotor 40 move backward. The backward movement of the knock member 30 and the rotor 40 is restricted by the engagement of the locking protrusion 31 of the knock member 30 with the restriction surface 25 provided at the rear end of the first guide groove 21 and the second guide groove 24 (FIG. 15(c)). As a result, the writing part 6a of the refill 6 arranged in front of the rotor 40 is retracted into the barrel 2, and the knock-type writing instrument 1 is in a non-writing state.

[0044] Fig. 16 is an assembled cross-sectional view of the knock member 30 and the rotor 40 of the knock type writing instrument 1 of Fig. 1. Although not shown in Fig. 16, as described above, two second regulating portions 47 are provided from the rear end portion of the insertion portion 41 of the rotor 40 toward the front. The first regulating portion 36 of the knock member 30 and the second regulating portion 47 of the rotor 40 are basically provided so as to overlap in position in the axial direction.

[0045] The rotor 40 rotates by a predetermined rotation angle for each knock operation, repeatedly engaging and disengaging with the outer cam 20. Since four outer cams 20 are provided at equal intervals along the circumferential direction on the inner surface of the inner cylinder 5, the rotor 40 alternately engages and disengages with the outer cam 20 four times while rotating once. Therefore, the predetermined rotation angle of the rotor 40 for each knock operation is specifically 45 degrees.

[0046] Fig. 17 is a cross-sectional view taken along line AA in Fig. 16, which corresponds to the knock-type writing instrument 1 during a knock operation, and Fig. 18 is a cross-sectional view taken along line AA in Fig. 16, which corresponds to the knock-type writing instrument 1 in a writing state. The state shown in Fig. 17 corresponds to the states shown in Fig. 14(b) and Fig. 15(b). The state shown in Fig. 18 corresponds to the states shown in Fig. 14(a), Fig. 14(c), Fig. 15(a) and Fig. 15(c).

[0047] As shown in Fig. 17, in the knock type writing instrument 1 during the knock operation, the first regulating portion 36 of the knock member 30 and the second regulating portion 47 of the rotor 40 do not coincide in the rotational direction, i.e., are not aligned in the radial direction. On the other hand, as shown in Fig. 18, in the knock type writing instrument 1 in the writing state, the first regulating portion 36 of the knock member 30 and the second regulating portion 47 of the rotor 40 coincide in the rotational direction, i.e., are aligned in the radial direction.

[0048] Here, eight first restricting portions 36 are provided on the knock member 30, and two second restricting portions 47 are provided on the rotor 40. The heights of the first restricting portions 36 from the inner surface of the knock member 30 and the heights of the second restricting portions 47 from the outer surface of the rotor 40 are set so that the outer diameter of an inscribed circle for the eight first restricting portions 36 is equal to or slightly smaller than the outer diameter of a circumscribed circle for the two second restricting portions 47.

[0049] The first restricting portion 36 and the second restricting portion 47 are aligned in the radial direction, so that the radial movement of the knock member 30 relative to the rotor 40 is restricted. In detail, for example, in the knock type writing instrument 1 in the writing state, the rotor 40 is biased against the outer cam 20 by the spring 7 via the refill 6, and as a result, is fixed. On the other hand, the biasing force of the spring 7 does not act on the knock member 30, but the radial movement of the knock member 30 relative to the fixed rotor 40 is restricted. Therefore, the knock member 30 does not rattle in the radial direction relative to the rotor 40. Furthermore, the outer diameter of the inscribed circle for the eight first restricting portions 36 is slightly smaller than the outer diameter of the circumscribed circle for the two second restricting portions 47, so that the first restricting portion 36 and the second restricting portion 47 come into contact with each other. As a result, the knock member 30 and the rotor 40 are engaged or fitted together, and the axial movement of the knock member 30 relative to the rotor 40 is restricted. Therefore, the knock member 30 does not rattle relative to the rotor 40 in the axial direction.

[0050] Since the first restricting portion 36 of the knock member 30 has a cross-sectional shape having an arc-shaped contour, the first restricting portion 36 can smoothly slide against the second restricting portion 47 of the rotating rotor 40. As a result, the first restricting portion 36 and the second restricting portion 47 can be smoothly aligned in the radial direction. Furthermore, since the second restricting portion 47 of the rotor 40 is provided with a flat top portion 47a, when the first restricting portion 36 and the second restricting portion 47 are aligned in the radial direction, the engagement or fitting with the arc-shaped top portion of the first restricting portion 36 can be more reliably performed. Furthermore, since the curved surface portion 36a is provided at the front end of the first restricting portion 36 and the chamfered portion 47b is provided at the rear end of the second restricting portion 47 of the rotor 40, even if the knock member 30 moves in the axial direction relative to the rotor 40 and the front end of the first restricting portion 36 collides with the rear end of the second restricting portion 47, the first restricting portion 36 and the second restricting portion 47 can smoothly slide against each other.

[0051] As described above, the rotor 40 rotates by 45 degrees with one knock operation, and each of the eight first regulating parts 36 is also spaced apart by a rotation angle of 45 degrees. Therefore, the first regulating parts 36 and the second regulating parts 47 are aligned in the radial direction not only when the knock type writing instrument 1 is in the writing state but also when it is in the non-writing state. In other words, during the knock operation, the first regulating parts 36 and the second regulating parts 47 are not aligned in the radial direction because the first regulating parts 36 are located between the adjacent second regulating parts 47 as shown in FIG. 17. Therefore, the knock operation is not hindered. In addition, in the knock type writing instrument 1 in the non-writing state, the knock member 30 and the rotor 40 are integrally biased by the spring 7 via the refill 6, so that the knock member 30 does not rattle against the rotor 40.

[0052] The knock type writing instrument 1 described above has eight first regulating parts 36, but may have only four first regulating parts 36 so that the first regulating parts 36 and the second regulating parts 47 are aligned only when the knock type writing instrument 1 is in a writing state. In short, it is sufficient that at least the first regulating parts 36 are provided in the number that the knock type writing instrument 1 is in a writing state during one rotation of the rotor 40. The first regulating parts 36 are provided according to the rotation angle of the rotor 40 by one knock operation. Furthermore, as long as the knock members 30 and the rotor 40 are regulated or locked in the number that the knock type writing instrument 1 is in a writing state during one rotation of the rotor 40, the shape and number of the first regulating parts 36 and the second regulating parts 47 may be configured arbitrarily.

[0053] For example, the first regulating portion 36 and the second regulating portion 47 are both ribs extending in the longitudinal direction, but one or both of the first regulating portion 36 and the second regulating portion 47 may be protrusions arranged at positions where the knock-type writing instrument 1 is regulated or locked when the writing instrument 1 is in a writing state. The second regulating portion 47 may be at least two, preferably three or more, protrusions or ribs arranged symmetrically with respect to the central axis of the rotor 40. By providing three or more second regulating portions 47 and regulating or locking the corresponding first regulating portions 36 at three or more points, any radial rattle of the knock member 30 relative to the rotor 40 can be reliably suppressed. In addition, one or both of the inner surface of the knock member 30 and the outer surface of the insertion portion 41 of the rotor 40 may be formed to have a substantially polygonal cross section. In this case, the corners of the polygon may be the first regulating portion 36 or the second regulating portion 47 so that the knock member 30 and the rotor 40 are regulated or locked.

[0054] The insertion portion 41 of the rotor 40 may be provided with one or more slits extending forward from the rear end opening. This allows the insertion portion 41 as a whole to expand and contract in the radial direction, absorbing manufacturing errors. In other words, it is reliably realized that the outer diameter of the inscribed circle for the eight first restricting portions 36 is equal to or slightly smaller than the outer diameter of the circumscribed circle for the two second restricting portions 47, and rattling of the knock member 30 relative to the rotor 40 can be reliably suppressed.

[0055] FIG. 19 is a perspective view of the second knock type writing instrument 100 in a non-writing state, FIG. 20 is a side view of the knock type writing instrument 100 in FIG. 19, FIG. 21 is a vertical cross-sectional view of the knock type writing instrument 100 in FIG. 19, and FIG. 22 is an exploded perspective view of the knock type writing instrument 100 in FIG. 19. As described above, common reference symbols are used for corresponding components throughout all the drawings. Compared with the first knock type writing instrument 1, the second knock type writing instrument 100 has the same refill 6, spring 7, outer cam 20, knock member 30, and rotor 40, and therefore descriptions of these components are omitted.

[0056] The knock-type writing instrument 100 has a barrel 102 equipped with a front barrel 103 and a rear barrel 104 that screws onto the outer surface of the rear end of the front barrel 103, an inner barrel 105 inserted inside the rear end of the barrel 102, a refill 6 that is a writing body that is disposed inside the barrel 102 and has a writing part 6a at one end, and a spring 7 that urges the refill 6 backward. The barrel 102 may be referred to as including the inner barrel 105.

[0057] An outer cam 20, which is a cam projection, is formed on the inner surface of the shaft tube 102, i.e., the inner surface of the inner tube 105. A knock member 30 is disposed inside the rear end of the shaft tube 102, i.e., inside the rear end of the inner tube 105, and a part of the knock member 30 protrudes rearward from the rear end of the inner tube 105. A rotor 40 is disposed in front of the knock member 30. The rear end face of the refill 6, which is biased rearward by the spring 7, abuts against the front end face of the rotor 40. Therefore, the rotor 40 is always biased rearward by the spring 7 via the refill 6. A clip holding portion 150 is provided on the side of the shaft tube 102. The clip holding portion 150 is composed of a first holding portion 150a provided on the front shaft 103 and a second holding portion 150b provided on the rear shaft 104. The clip member 160 is attached to the shaft tube 102 by the clip holding portion 150.

[0058] FIG. 23 is a vertical cross-sectional view of the front shaft 103 of the knock-type writing instrument 100 of FIG. 19. The front shaft 103 is a cylindrical member. The outer surface of the rear end of the front shaft 103 is provided with a male thread portion 103a that screws into the rear shaft 104. The outer surface of the front shaft 103 from the front of the male thread portion 103a to the front end opening from which the writing part 6a projects is covered by a grip portion 110 that is formed by two-color molding during the manufacture of the front shaft 3. In the assembled state of the knock-type writing instrument 100, the entire exposed outer surface of the front shaft 103 is covered by the grip portion 110, so that the user can grip any part of the front shaft 103 when writing. The grip portion 110 is formed from the same material as the grip portion 10 of the first knock-type writing instrument 1 described above.

[0059] The inner surface of the front end of the front shaft 103 is provided with an annular support surface 103c facing rearward. Four first ribs 103d and two second ribs 103e are provided behind the support surface 103c, each having a surface facing radially inward and extending in the front-rear direction. The two second ribs 103e are arranged at positions facing each other across the central axis of the front shaft 103. The four first ribs 103d are divided into two sets, and are arranged at equal intervals between each of the two second ribs 103e. The four first ribs 103d and the two second ribs 103e are arranged at equal intervals along the circumferential direction. A rectangular through hole 103f is formed on the side surface of the front shaft 103 behind each of the four first ribs 103d. In the two-color molding process, when grip portion 110 is molded after front shaft 103 is molded, the resin material of grip portion 110 passes through through-hole 103f and enters the inside of front shaft 103, forming protruding buffer portion 111. In other words, buffer portion 111 consists of a part of grip portion 110. Buffer portion 111 is formed integrally with first rib 103d, and has buffer surface 112 that is inclined toward the front of front shaft 103.

[0060] FIG. 24 is a perspective view of the rear barrel 104 of the knock-type writing instrument 100 of FIG. 19, and FIG. 25 is a vertical cross-sectional view of the rear barrel 104 of FIG. 24. The rear barrel 104 is a cylindrical member. The inner surface of the front end of the rear barrel 104 is provided with a female thread portion 104a that can be screwed with the male thread portion 103a of the front barrel 103. Note that, at the start point of the male thread portion 103a of the front barrel 103, that is, at the end where the helical track of the male thread portion 103a is extended from the rear end toward the rear, a first locking portion similar to that of the first knock-type writing instrument 1 is provided, although not shown. On the other hand, the female thread portion 104a of the rear barrel 104 is provided with a second locking portion similar to that of the first knock-type writing instrument 1, although not shown. In the second knock type writing instrument 100, as in the first knock type writing instrument 1, the first locking portion and the second locking portion are locked to prevent unintentional release of the screw engagement.

[0061] A first holding portion 150a is provided on the side surface of the rear end portion of the rear axle 104. The first holding portion 150a has a first notch portion 151a formed in a substantially rectangular shape that extends forward from the rear end opening of the rear axle 104, and a cylindrical column portion 152 that is provided to straddle the first notch portion 151a and has a central axis perpendicular to the central axis of the rear axle 104. A part of the base of the column portion 152 is hollowed out by the first notch portion 151a, and a first support portion 153 that faces radially inward is provided. The tip of the column portion 152 is provided flat in a circular shape. An insertion hole 154 with a rectangular cross section that extends parallel to the central axis of the rear axle 104 is defined on the side surface of the column portion 152. The insertion hole 154 communicates with the first notch portion 151a.

[0062] Fig. 26 is a perspective view of the inner tube 105 of the knock-type writing instrument 100 of Fig. 19, Fig. 27 is a side view of the inner tube 105 of Fig. 26, and Fig. 28 is a vertical cross-sectional view of the inner tube 105 of Fig. 26. The inner tube 105 is a cylindrical member. The outer cam 20 described above is provided on the inner surface of the rear end of the inner tube 105.

[0063] A second holding portion 150b is provided on the side surface of the inner tube 105 near the rear end. The second holding portion 150b has a base portion 155 that protrudes radially outward from the side surface of the inner tube 105. A substantially rectangular second cutout portion 151b is formed so as to extend rearward from the front end opening of the inner tube 105 to the base portion 155. A rear wall 157 is provided on the rear side of the base portion 155. The surface of the rear wall 157 is formed in a cylindrical surface shape so as to be integrated with the columnar pillar portion 152 of the rear shaft 104 when the rear wall 157 is attached to the rear shaft 104 as described later. On the front side of the base portion 155, a second support portion 158 facing radially outward and a recessed portion 159 extending obliquely radially outward continuously from the rear of the second support portion 158 are provided in this order from the front end. An end portion 155a is provided at the radial tip of the base portion 155.

[0064] FIG. 29 is a perspective view of the clip member 160 of the knock-type writing instrument 100 of FIG. 19. In FIG. 29, the right side is the rear side of the knock-type writing instrument 100. The clip member 160 is formed by punching and bending a plate-shaped member made of metal such as stainless steel using press processing or the like. Therefore, the clip member 160 is a plate-shaped member as a whole. Specifically, the clip member 160 has a stepped attachment portion 161 formed so as to branch off from the clip member 160. The attachment portion 161 is formed simultaneously with the formation of the first opening 162 further forward and the second opening 163 further rearward. As a result, the clip member 160 made of an integral plate material having approximately the same width as a whole is defined. The front end of the clip member 160 is curved radially outward, and a convex portion 164 formed thereby grips an article between the clip member 160 and the rear shaft 104. The mounting portion 161 has a curved portion 165 that is curved in an arc shape from the rear end of the first opening 162, a clamping portion 166 that bends approximately 90 degrees from the curved portion 165 and extends forward, and a tip portion 167 that bends approximately 90 degrees from the clamping portion 166 and extends radially inward.

[0065] 30 is a vertical cross-sectional view for explaining the attachment of the clip member 160 of the knock-type writing instrument 100 of FIG. 19. First, as shown in FIG. 30(a), the clip member 160 is placed on the base portion 155 of the second holding portion 150b of the inner tube 105. Specifically, the clamping portion 166 of the clip member 160 is placed on the second support portion 158, and the tip portion 167 of the clip member 160 is placed on the rear end portion of the second cutout portion 151b, in other words, on the front end portion of the base portion 155. Alternatively, the rear portion of the curved portion 165 of the clip member 160 is placed on the end portion 155a of the base portion 155, and the front portion of the curved portion 165 of the clip member 160 is placed in the recess 159.

[0066] Next, as shown in FIG. 30(b), the base portion 155 of the second holding portion 150b of the inner tube 105 is aligned in the rotational direction so as to be received in the first cutout portion 151a of the rear axle 104, and the front end of the inner tube 105 is inserted into the inside of the rear end portion of the rear axle 104. At this time, the front end of the clip member 160 is inserted into the insertion hole 154 of the first holding portion 150a of the rear axle 104. Specifically, the rear end of the clip member 160 is moved radially inward, and the front end of the clip member 160 is moved radially outward with the end portion 155a of the base portion 155 as a fulcrum. Thereby, the front end of the clip member 160 can be inserted into the insertion hole 154.

[0067] Next, as shown in FIG. 30(c), the inner cylinder 105 together with the clip member 160 is further inserted and press-fitted into the rear axle 104. As a result, the first holding portion 150a and the second holding portion 150b are fitted together to form the clip holding portion 150. That is, the base portion 155 of the second holding portion 150b and the clip member 160 attached to the base portion 155 are disposed within the column portion 152 of the first holding portion 150a. Also, the clamping portion 166 of the clip member 160 is clamped radially between the first support portion 153 of the first holding portion 150a and the second support portion 158 of the second holding portion 150b. In other words, the mounting portion 161 of the clip member 160 is clamped radially between the rear axle 104 and the inner cylinder 105. As a result, the clip member 160 is attached to the barrel 102 by the clip holding portion 150 which is integrally formed by the first holding portion 150a and the second holding portion 150b.

[0068] The clip holding portion 150 is formed into a generally cylindrical shape by the pillar portion 152 of the first holding portion 150a and the rear wall 157 of the second holding portion 150b. The clip member 160 is arranged so as to penetrate the generally cylindrical clip holding portion 150 from the side along the central axis of the knock-type writing instrument 100. Therefore, the attachment portion of the clip member 160, i.e., the clamping portion 166, is generally concealed by the generally cylindrical clip holding portion 150. Therefore, as shown in Figs. 19 and 20, the attachment structure, i.e., the portion of the clip member 160 involved in attachment, cannot be seen from the outside, so that the design of the attachment structure of the clip member 160 can be improved. In addition, since there are few unnecessary gaps in the attachment structure, the intrusion of dust and the like into the attachment structure is prevented. Furthermore, in the knock-type writing instrument 100, the clip member 160 has no connecting portion that is press-fitted or fitted to the rear barrel 104 or the inner tube 105, and therefore the clip member 160 can be more easily disassembled by removing the inner tube 105 from the rear barrel 104. As a result, the rear barrel 104, the inner tube 105, or the clip member 160 can be easily recycled or reused.

[0069] In the clip member 160, the front end of the clip member 160 is biased radially inward due to the shape of the mounting portion 161, particularly the shape of the curved portion 165. Therefore, an article can be gripped between the convex portion 164 of the clip member 160 and the outer surface of the shaft tube 102, specifically the outer surface of the rear shaft 104. When releasing the grip, the rear end of the clip member 160 is pressed radially inward, and the mounting portion 161 is elastically deformed with the end portion 155a of the base portion 155 as a fulcrum. As a result, the front end of the clip member 160 moves radially outward, and the grip can be released. Since the clip holding portion 150 is provided with a sufficiently large insertion hole 154, the swinging of the clip member 160 is not hindered.

[0070] FIG. 31 is a vertical cross-sectional view of the front end of the knock-type writing instrument 100 of FIG. 19. The refill 6 has the writing part 6a described above, an ink containing tube 6b that contains ink to be supplied to the writing part 6a, and a joint 6c that connects the writing part 6a and the ink containing tube 6b. The writing part 6a is a ballpoint pen tip that holds a ball at its tip. The front end of the spring 7 is supported by the support surface 103c of the front shaft 103, and the rear end of the spring 7 is supported by the front end surface of the flange part 6d that is provided on the joint 6c and protrudes radially outward. As a result, the refill 6 is biased backward by the spring 7. The spring 7 is surrounded by the first rib 103d and the second rib 103e, thereby restricting radial bending.

[0071] For example, if the knock-type writing instrument 100 is accidentally dropped on the floor from the rear end side, that is, from the knock member 30 side, the refill 6 will move relatively forward rapidly within the barrel 102 due to the impact and recoil of the drop. The movement of the refill 6 is restricted by the collision of the flange portion 6d of the joint 6c with the buffer surface 112 of the buffer portion 111. The buffer portion 111 is made of a softer viscoelastic material than the front barrel 103, so it can mitigate the impact of the refill 6 when it collides. If the buffer portion 111 did not exist, the refill 6 would collide with the inner surface of the front barrel 103 made of hard plastic. As a result, the impact is not sufficiently mitigated, and there is a risk that the ball held at the tip of the writing portion 6a will fly out due to inertia. The impact of the refill 6 is mitigated by the collision with the buffer surface 112, so that the ball can be prevented from flying out and other damage to the refill 6 can be reduced.

[0072] The buffer portion 111 may have any shape and arrangement as long as it penetrates the barrel 102 from the outside to the inside and can absorb the impact of the refill 6. For example, in the knock-type writing instrument 100, the flange portion 6d of the joint 6c is arranged to collide with the buffer portion 111, but a through hole may be provided near the front end opening of the front barrel 103, and a corresponding buffer portion may be provided in a two-color molding process. In this case, the writing portion 6a, not the joint 6c of the refill 6, collides with the buffer portion, and the impact is absorbed. The buffer portion may be provided by penetrating a separate member from the outside to the inside of the barrel 102, instead of the two-color molding process. The configuration of the buffer portion 111 that absorbs the impact of the refill 6 in the second knock-type writing instrument 100 may be applied to the first knock-type writing instrument 1.

[0073] The refill 6 may be a ballpoint pen or other type of writing instrument such as a marking pen, a touch pen, an eraser, etc. In addition, a part or all of the knock member 30 including the top cap 35 may be an erasing portion that erases handwriting made by a knock-type writing instrument.

[0074] The refill 6 may be a ballpoint pen containing thermochromic ink. Here, the thermochromic ink refers to ink that has the property of maintaining a predetermined color (first color) at room temperature (e.g., 25°C), changing to another color (second color) when heated to a predetermined temperature (e.g., 60°C), and then returning to the original color (first color) when cooled to a predetermined temperature (e.g., -5°C). In a thermochromic writing instrument using thermochromic ink, the second color is made colorless, and the term "erasing" refers to heating a line drawn in the first color (e.g., red) to make it colorless. Therefore, the friction member, which is the erasing part, rubs against the writing surface on which the line was drawn to generate frictional heat, thereby changing the drawn line to colorless, that is, erasing it. It should be noted that the second color may be a color other than colorless.

[0075] The above has been described using a knock-type writing instrument as an example of a writing instrument, but the configurations or structures that are common to knock-type writing instruments and other writing instruments, such as cap-type writing instruments and multi-core writing instruments, such as the structure of the first locking portion of the male thread portion and the second locking portion of the female thread portion or the attachment structure of the clip member, can be similarly applied to other writing instruments.

[0076] For example, the structure of the first locking portion of the male threaded portion and the second locking portion of the female threaded portion includes a male threaded member having a male threaded portion and a cylindrical female threaded member having a female threaded portion and capable of being screwed with the male threaded member, the male threaded member has the first locking portion, the female threaded member has the second locking portion, and the first locking portion and the second locking portion climb over each other when the male threaded member and the female threaded member are screwed together, so long as the first locking portion and the second locking portion are locked together when the male threaded member and the female threaded member are released from being screwed together, the male threaded member and the female threaded member may be selected arbitrarily. For example, the male threaded member and the female threaded member may be a front shaft that is screwed onto a tip member and a rear end portion of the tip member, or a cap and a crown that is screwed onto a rear end portion of the cap, in addition to the above-mentioned front shaft 3 and rear shaft 4.

[0077] The mounting structure of the clip member includes a cylindrical first member having a first holding portion, a second member having a second holding portion and being inserted into the inside of the rear end portion of the first member to be detachably fitted with the first member, and a clip member having an attachment portion, and the first member and the second member may be selected arbitrarily as long as the attachment portion of the clip member is clamped radially between the first holding portion and the second holding portion and the clip member is attached to the first member. For example, the first member and the second member may be a cap and a crown that fits onto the rear end portion of the cap, other than the above-mentioned rear body 104 and inner cylinder 105.

[0078] In the above-mentioned knock-type writing instrument 100, the first holding part 150a and the second holding part 150b are fitted together to form the clip holding part 150 having a cylindrical shape as a whole, but in consideration of design, the first holding part and the second holding part may be configured to have a polygonal prism shape, for example a hexagonal prism shape, other than a cylindrical shape. In addition, the attachment part may be configured in any shape other than the above-mentioned stepped shape, as long as it can be held between the first holding part and the second holding part in the radial direction. For example, the attachment part may be simply arc-shaped. [Explanation of symbols]

[0079] 1. Knock-type writing implement 2 shaft cylinder 3 Front axle 4 Rear axle 5 Inner cylinder 20 Outer Cam 30 Knock parts 31 Locking protrusion 36 First Regulatory Department 40 Rotor 41 Insertion section 47 Second Regulatory Department 100 Knock-type writing implement 102 Shaft cylinder 103 Front axis 104 rear axle 105 Inner cylinder 150 Clip holder 150a 1st holding part 150b 2nd holding part 160 Clip member 161 Mounting part

Claims

1. A knock-type writing instrument comprising a barrel, a knock member formed cylindrically and having a cam surface, and a rotor disposed in front of the knock member, the rotor having a cam receiving surface that cooperates with the cam surface of the knock member and an insertion portion that can be inserted into the knock member, a first restricting portion is formed on an inner surface of the knock member, and a second restricting portion is formed on an outer surface of the insertion portion of the rotor, When a knock operation causes the cam surface and the cam receiving surface to cooperate with each other to rotate the rotor relative to the knock member and the knock-type writing instrument is in a writing state, the first regulating portion and the second regulating portion are aligned in the radial direction to regulate the radial movement of the knock member relative to the rotor, A knock-type writing implement, characterized in that the first restriction portion and the second restriction portion are configured so as not to be aligned in the radial direction during a knock operation.

2. 2. The knock-type writing instrument according to claim 1, wherein the first regulating portion and the second regulating portion are configured to abut when the first regulating portion and the second regulating portion are aligned radially, so that the knock member and the rotor are engaged in the axial direction.

3. 3. The knock-type writing instrument according to claim 1, wherein the first regulating portion and the second regulating portion are protrusions or ribs extending in the longitudinal direction, and the first regulating portion is provided according to a rotation angle of the rotor by a single knock operation.

4. 3. A knock-type writing instrument as described in claim 1 or 2, further comprising a refill with a ballpoint tip holding a ball at its tip, a buffer section made of a viscoelastic material penetrating from the outside to the inside of the barrel, configured so that the forward movement of the refill is regulated by contact with the buffer section, and a grip section is provided on the outer surface of the barrel, and the buffer section consists of a part of the grip section.

5. 3. The knock-type writing instrument according to claim 1 or 2, comprising a male threaded member having a male threaded portion, and a tubular female threaded member having a female threaded portion and capable of being screwed into the male threaded member, the male threaded portion having a first locking portion and the female threaded portion having a second locking portion, the first locking portion and the second locking portion climbing over each other when the male threaded member and the female threaded member are screwed together, so that the first locking portion and the second locking portion lock together when the male threaded member and the female threaded member are unscrewed from each other.

Images