Ballpoint pen

Abstract

To provide a ballpoint pen that prevents vibration of a knock button that is pressed down during writing.SOLUTION: The ballpoint pen includes a knock spring interposed between the barrel and the refill, a rotor having a cam formed on its rear end surface and a push rod protruding rearward, a knock button into which the push rod is inserted, an inner cam formed on the inner surface near the rear end of the barrel, a plurality of engaging cams formed on the rear end surface of the rotor and meshing with the inner cam, and an inclined surface which is the tip surface of the rotor and inclined rearward, and is configured so that when the rotor is pressed by the knock button and the engaging cam engages with the inner cam, the refill is urged rearward by the knock spring, and the inclined surface is pressed rearward by the rear end of the refill, causing the rotor to incline toward the side of the inclined surface which is closest to the rear with respect to the axis, and the push rod presses the inner surface of the knock button to fix the knock button to the barrel.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a knock-type ballpoint pen. [Background technology]

[0002] Regarding so-called knock-type ballpoint pens, in which the tip of the built-in refill is extended or retracted from the tip of the barrel by pressing a knock button protruding from the rear end of the barrel, the technologies described in the following Patent Documents 1 to 5 are disclosed.

[0003] In these prior arts, a cam is formed on the rotor that is pressed by the knock button. The knock button and the rotor are urged backward by a knock spring housed in the barrel. When the knock button is pressed against the urging force of the knock rod, the rotor moves forward and the cam of the rotor engages with a cam formed on the inner circumference of the barrel. At this time, the knock spring urges the rotor backward to maintain this engaged state. In this state, the tip of the refill protrudes from the tip of the barrel to maintain the writing state.

[0004] When the knock button is pressed again from this state, the engagement between the rotor cam and the barrel cam is released. The rotor is then biased backward by the knock spring and moves backward. As a result, the tip of the refill retracts into the barrel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-70970 A [Patent Document 2] JP 2009-34879 A [Patent Document 3] JP 2015-3443 A [Patent Document 4] JP 2016-37011 A [Patent Document 5] JP 2016-107615 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a knock-type ballpoint pen, when the knock button is pressed down during writing, the knock button and the rotor do not physically engage, and the knock button is usually free. Therefore, the knock button may vibrate along with the vibration during writing. The ballpoint pen of the present disclosure aims to prevent the vibration of the knock button that is pressed down during writing. [Means for solving the problem]

[0007] (1) First Aspect A ballpoint pen according to a first aspect of the present disclosure comprises a barrel, a refill that is housed in the barrel and whose tip appears and disappears from the barrel in response to a knock operation, a knock spring that is interposed between the barrel and the refill and urges the refill rearward, a rotor that has a cam formed on its rear end surface and a cam portion that is generally cylindrical in shape and a pressure rod that protrudes rearward from the cam portion and has a smaller diameter, and that abuts against the rear end of the refill, a knock button that protrudes partially from the rear end of the barrel while abutting against the rear end of the cam portion when the pressure rod is inserted into the internal space, an inner cam formed on the inner surface near the rear end of the barrel, a knock cam formed on the tip surface of the knock button, a rotating cam formed on the rear end surface of the rotor and engaging with the knock cam, a plurality of engagement cams formed on the outer periphery of the rotating cam and engaging with the inner cam, and a tip surface of the rotor that is inclined rearward.

[0008] The ballpoint pen of an embodiment of the present disclosure is further configured so that, when the rotor is pressed by the knock button and the engagement cam is engaged with the inner cam, the refill is urged rearward by the knock spring, and the inclined surface is pressed rearward by the rear end of the refill, causing the rotor to incline toward the side of the inclined surface that is closest to the rear relative to the axis, and the pressure rod presses the inner surface of the knock button to fix the knock button to the barrel.

[0009] When the knock button is pressed against the force of the knock spring, the knock button pushes the rotor forward with the knock cam of the knock button meshing with the rotating cam of the rotor. As the rotor is pushed forward, the rotor pushes the refill forward. Then, the engagement cam of the rotor engages with the inner cam of the barrel, keeping the tip of the refill protruding from the barrel and entering the writing state.

[0010] In this state, the refill is urged backward by the knock spring. The rear end of the refill then abuts against and presses against the inclined surface of the rotor. This causes the rotor to incline toward the side of the inclined surface closest to the rear, relative to the axis. As the rotor inclines, the push rod presses against the inner surface of the knock button, pressing the knock button toward the pressed side. The knock button is clamped between the push rod and the inner surface of the barrel, preventing it from moving. This prevents the knock button from vibrating when writing.

[0011] (2) Second Aspect A ballpoint pen of a second aspect of the present disclosure has the same configuration as the first aspect, and further comprises: a plurality of engagement cams each including an inclined cam whose engagement position with the inner cam is closer to the front than the others and which is located on the side of the inclined surface closest to the front; and a fulcrum cam which faces the inclined cam across the axis and whose engagement position with the inner cam is closer to the rear than the others and which is located on the side of the inclined surface closest to the rear; and it is desirable that the rotor tilts toward the fulcrum cam when the inclined cam engages with the inner cam.

[0012] As described in the first embodiment above, in the writing state, the rear end of the refill abuts against and presses against the inclined surface of the rotor. This causes the rotor to incline toward the rearmost side of the inclined surface relative to the axis. At this time, among the engagement cams that engage with the inner cam of the barrel, the fulcrum cam located at the rearmost position and the inclined cam located at the frontmost position simultaneously engage with the inner cam, causing the rotor to incline toward the fulcrum cam.

[0013] (3) Third aspect A ballpoint pen according to a third aspect of the present disclosure has, in addition to the configuration of the second aspect, a forward protrusion that protrudes forward on the side of the inclined surface on which the fulcrum cam is provided.

[0014] As described in the first embodiment above, in the writing state, the rear end of the refill abuts against the inclined surface of the rotor and presses it. At this time, the rear end of the refill abuts against this forward protrusion, which makes it easier for the rear end of the refill to press backward the position of the inclined cam located on the opposite side of this forward protrusion. As a result, the rotor is more likely to tilt toward the fulcrum cam. Effect of the Invention

[0015] Since the ballpoint pen of the present disclosure is configured as described above, it is possible to prevent vibration of the knock button that is pressed during writing by pressing the knock button with the tilt of the rotor. [Brief description of the drawings]

[0016] [Figure 1A] FIG. 1 is a front view of a ballpoint pen according to a first embodiment. [Figure 1B] FIG. 1B is a side view of the ballpoint pen of FIG. 1A. [Figure 1C] FIG. 2 is a cross-sectional view of FIG. 1A. [Figure 2A] FIG. 1B is a front view of an inner barrel used in the ballpoint pen of FIG. 1A. [Figure 2B] FIG. 2B is a side view of the inner shaft of FIG. 2A. [Figure 2C]FIG. 2B is a plan view of the inner shaft of FIG. 2A. [Figure 2D] FIG. 2B is a bottom view of the inner shaft of FIG. 2A. [Figure 2E] FIG. 2B is a cross-sectional view taken along line IIa-IIa of FIG. 2A. [Figure 2F] FIG. 2B is a cross-sectional view taken along line IIb-IIb of FIG. 2E. [Figure 3A] FIG. 1B is a front view of a rotor used in the ballpoint pen of FIG. 1A. [Figure 3B] FIG. 3B is a side view of the rotor of FIG. 3A. [Figure 3C] FIG. 3B is a front perspective view of the rotor of FIG. 3A. [Figure 3D] FIG. 3B is a rear perspective view of the rotor of FIG. 3A. [Figure 3E] FIG. 3B is a plan view of the rotor of FIG. 3A. [Figure 3F] FIG. 3B is a bottom view of the rotor of FIG. 3A. [Figure 3G] FIG. 3B is a cross-sectional view taken along line III-III of FIG. 3A. [Figure 4A] 1B is a front view of a knock button used in the ballpoint pen of FIG. 1A. [Figure 4B] FIG. 4B is a side view of the knock button of FIG. 4A. [Figure 4C] FIG. 4B is a rear perspective view of the knock button of FIG. 4A. [Figure 4D] FIG. 4B is a plan view of the knock button of FIG. 4A. [Figure 4E] FIG. 4B is a bottom view of the knock button of FIG. 4A. [Figure 4F] 4B is a cross-sectional view of FIG. 4A taken along line IV-IV. [Diagram 5] FIG. 1C shows an enlarged view of the rear end portion. [Figure 6A] FIG. 2 is a front view of the ballpoint pen in a writing state. [Figure 6B] FIG. 6B is a perspective view of the ballpoint pen of FIG. 6A. [Figure 6C] 6B is a cross-sectional view taken along line VI-VI of FIG. 6A. [Figure 7] FIG. 6C shows an enlarged view of the rear end portion. [Figure 8A] FIG. 11 is a front view of a ballpoint pen according to a second embodiment. [Figure 8B] FIG. 8B is a side view of the ballpoint pen of FIG. 8A. [Figure 8C] FIG. 8B is a cross-sectional view taken along line VIII-VIII of FIG. 8A. [Figure 9A] FIG. 8B is a front view of a rotor used in the ballpoint pen of FIG. 8A. [Figure 9B] FIG. 9B is a side view of the rotor of FIG. 9A. [Figure 9C] FIG. 9B is a rear perspective view of the rotor of FIG. 9A. [Figure 9D] FIG. 9B is a front perspective view of the rotor of FIG. 9A. [Figure 9E] FIG. 9B is a plan view of the rotor of FIG. 9A. [Figure 9F] FIG. 9B is a bottom view of the rotor of FIG. 9A. [Figure 9G] IX-IX cross-sectional view of FIG. 9A. [Figure 10] FIG. 8C shows an enlarged view of the rear end portion. [Figure 11A] 8B is a front view of the ballpoint pen of FIG. 8A in a state where the knock button is pressed. [Figure 11B] FIG. 11B is a side view of the ballpoint pen of FIG. [Figure 11C] XI-XI cross-sectional view of FIG. 11A. [Figure 12] FIG. 11C shows an enlarged view of the rear end portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the reference numerals commonly used in the drawings indicate common configurations or components even if they are not mentioned in the description of each drawing. In the following description, the side of the ballpoint pen where the ballpoint pen tip is located is referred to as the "front end", and the opposite side, i.e., the side where the knock button is located, is referred to as the "rear end". In addition, at any position in the ballpoint pen, the direction of the front end is referred to as the "forward" and the direction of the rear end is referred to as the "rear".

[0018] (1) First embodiment (1-1) Overall configuration of ballpoint pen 10 The overall configuration of a ballpoint pen 10 of a first embodiment will be described with reference to Fig. 1A to Fig. 1C. Fig. 1A is a front view of the ballpoint pen 10, Fig. 1B is a side view of the ballpoint pen 10 of Fig. 1A, and Fig. 1C is a cross-sectional view taken along line II of Fig. 1A. Figs. 1A to 1C show the ballpoint pen 10 in a non-writing state.

[0019] The ballpoint pen 10 of this embodiment has an external appearance in which a knock button 70 protrudes from the rear end of a barrel 15 equipped with a clip 33. The barrel 15 is a substantially cylindrical member, and is composed of an outer barrel 20 that houses a refill 50 (FIG. 1C), an inner barrel 30 attached to the rear end of the outer barrel 20, and a front barrel 40 attached to the front end of the outer barrel 20. The outer barrel 20, the inner barrel 30, and the front barrel are molded from hard resin. A grip 21 made of an elastic resin material such as an elastomer is attached to the outer peripheral surface of the front end side of the outer barrel 20. The front end of the outer barrel 20 has a reduced outer diameter and a male screw portion 22 (FIG. 1C) with a screw thread cut on the outer peripheral surface.

[0020] Lead barrel 40 is composed of large diameter section 41 located at the rear and having a relatively large outer diameter, and tapered section 43 located at the front and whose outer diameter gradually decreases toward the tip. The inner peripheral surface of large diameter section 41 is female threaded section 42 (FIG. 1C) with a screw thread. The tip of lead barrel 40 is provided with tip opening 46 through which ballpoint pen tip 53 (FIG. 1C) appears. Lead barrel 40 is attached to outer barrel 20 by female threaded section 42 being screwed into male threaded section 22. As shown in FIG. 1C, inner barrel 30 is composed of exposed section 31 exposed to the outside, insertion section 32 inserted into outer barrel 20, and clip 33 formed on the front side of exposed section 31 and extending forward. Gasket 12 formed of an elastic resin material is interposed between exposed section 31 of inner barrel 30 and the rear end of the outer circumference of outer barrel 20. Details of the structure of inner barrel 30 will be described later.

[0021] As shown in FIG. 1C, the refill 50 is accommodated in the barrel 15. The refill 50 is composed of a tubular ink containing tube 51 made of a relatively soft resin, a joint 52 attached to the tip of the ink containing tube 51, and a ballpoint pen tip 53 attached to the tip of the joint 52. The ink containing tube 51 contains ink 51A, and further contains a follower 51B behind the ink 51A. The ballpoint pen tip 53 has a structure in which a metallic writing ball 53B is held at the tip of a metallic, substantially cylindrical holder 53A. The joint 52 is a member that connects the ink containing tube 51 and the ballpoint pen tip 53, and is composed of a rear connection part 52A with a relatively large diameter into which the tip of the ink containing tube 51 is press-fitted, and a front connection part 52B with a relatively small diameter into which the rear end of the ballpoint pen tip 53 is press-fitted.

[0022] As shown in Fig. 1C, a rotor 60 is attached inside the exposed portion 31 of the inner shaft 30. The tip of the rotor 60 abuts against the rear end of the refill 50. The rear end portion of the rotor 60 is inserted into and abuts against the internal space of the knock button 70. The structures of the rotor 60 and the knock button 70 will be described in detail later.

[0023] 1C, a knock spring 11 is interposed between a step between rear connecting portion 52A and front connecting portion 52B of joint 52 and a step formed inside tapered portion 43 of front barrel 40. This knock spring 11 constantly urges refill 50, rotor 60, and knock button 70 rearward.

[0024] (1-2) Inner shaft 30 The structure of the inner shaft 30 used in the ballpoint pen 10 of this embodiment will be described with reference to Figures 2A to 2F. Figure 2A is a front view of the inner shaft 30, Figure 2B is a side view of the inner shaft 30, Figure 2C is a plan view of the inner shaft 30, Figure 2D is a bottom view of the inner shaft 30, Figure 2E is a cross-sectional view taken along line IIa-IIa of Figure 2A, and Figure 2F is a cross-sectional view taken along line IIb-IIb of Figure 2E.

[0025] The inner shaft 30 is composed of an exposed portion 31 exposed to the outside, an insertion portion 32 inserted into the outer shaft 20, and a clip 33 formed on the front side of the exposed portion 31 and extending forward. The exposed portion 31 has a generally cylindrical shape with an outer shape that is slightly narrowed toward the rear. The tip side of the exposed portion 31 is inclined so that the front side is longer and the rear side is shorter (FIG. 2B) in accordance with the shape of the rear end side of the outer shaft 20 to be attached (see FIG. 1B). The rear end surface of the exposed portion 31 is also inclined in the same manner. Furthermore, a rear end opening 38 through which the knock button 70 (FIGS. 1A to 1C) penetrates is formed at the rear end of the exposed portion 31 (FIGS. 2A, 2C, and 2E). The insertion portion 32 is formed in a generally cylindrical shape with a smaller diameter than the exposed portion 31. The tip of the insertion portion 32 is obliquely cut to match the inclination of the tip side of the exposed portion 31.

[0026] As shown in Fig. 2E and Fig. 2F, eight guide ridges 34 extending in the axial direction are evenly arranged on the inner peripheral surface of the exposed portion 31. Four relatively deep first guide grooves 36 and four relatively shallow second guide grooves 37 are evenly arranged alternately between the guide ridges 34 (Fig. 2F). An inner peripheral cam 35 that engages with an engagement cam 64 (Fig. 3A) of the rotor 60 described later is formed at the tip of each guide ridge 34 (Figs. 2D and 2E). In addition, the inner diameter of the inner peripheral surface of the inner shaft 30 is slightly smaller near the rear end, forming a rear end step 39 (Fig. 2E).

[0027] (1-3) Rotor 60 The structure of the rotor 60 used in the ballpoint pen 10 of this embodiment will be described with reference to Figures 3A to 3G. Figure 3A is a front view of the rotor 60, Figure 3B is a side view of the rotor 60, Figure 3C is a front perspective view of the rotor 60, Figure 3D is a rear perspective view of the rotor 60, Figure 3E is a plan view of the rotor 60, Figure 3F is a bottom view of the rotor 60, and Figure 3G is a cross-sectional view taken along line III-III in Figure 3A.

[0028] The rotor 60 is composed of a generally cylindrical cam portion 61 on which a cam is formed, and a columnar pressing rod 62 that has a smaller diameter than the cam portion 61 and protrudes to the tip. A sawtooth-like rotating cam 63 with eight peaks and eight valleys alternately and evenly arranged is formed on the tip surface of the cam portion 61 (Fig. 3D). Meanwhile, the rear end edge of the cam portion 61 forms a flange 68 with an increased outer diameter. On the inner peripheral surface of the cam portion 61, four inner peripheral ribs 65 extending in the axial direction are evenly arranged (Figs. 3C, 3F, and 3G).

[0029] Four sliding ridges 67 extending in the axial direction are evenly arranged on the outer peripheral surface of the cam portion 61. An engagement cam 64 is formed at the tip of the sliding ridges 67 as an inclined surface whose height increases from right to left when viewed from the front. The sliding ridges 67 are formed at a position where the inclination of the engagement cam 64 coincides with the inclination of the rotating cam 63 (FIGS. 3A, 3B, and 3D). The outer peripheral surface of the sliding ridges 67 coincides with the outer peripheral surface of the flange 68 (FIGS. 3A to 3D, and 3E). The sliding ridges 67 are recessed into the first guide groove 36 (FIG. 2F) of the inner shaft 30, and slide back and forth along the first guide groove 36.

[0030] Of the four engagement cams 64, one has a cam surface located closer to the tip than the others, and is referred to as an inclined cam 64A (Figs. 3A, 3B, 3D, 3E). Of the four engagement cams 64, the cam surface of the other is located closer to the rear end than the others, and is referred to as a fulcrum cam 64B (Figs. 3B, 3D, 3E). The cam surface of the fulcrum cam 64B coincides with the cam surface of the rotating cam 63 (Figs. 3B, 3E). The cam surfaces of the engagement cams 64 and the engagement cams 64 other than the fulcrum cam 64B are located closer to the tip than the cam surface of the rotating cam 63 (Figs. 3A, 3B, 3D).

[0031] The tip end surface of the rotor 60 is an inclined surface 66 that is inclined backward (FIGS. 3B, 3C, 3F, and 3G). Specifically, the side of the inclined surface 66 that is closest to the front corresponds to the side where the inclined cam 64A is located. Also, the side of the inclined surface 66 that is closest to the rear corresponds to the side where the fulcrum cam 64B is located (FIGS. 3B and 3G).

[0032] (1-4) Knock button 4A to 4F, the structure of the knock button 70 used in the ballpoint pen 10 of this embodiment will be described. Fig. 4A is a front view of the knock button 70, Fig. 4B is a side view of the knock button 70, Fig. 4C is a rear perspective view of the knock button 70, Fig. 4D is a plan view of the knock button 70, Fig. 4E is a bottom view of the knock button 70, and Fig. 4F is a cross-sectional view taken along line IV-IV in Fig. 4A.

[0033] The knock button 70 is composed of a generally cylindrical cam barrel portion 71 located at the front and a generally cylindrical protruding portion 72 located at the rear and tapering slightly toward the rear. The cam barrel portion 71 is a portion that slides back and forth inside the exposed portion 31 (FIG. 2E) of the inner shaft 30. The protruding portion 72 is a portion that protrudes from the rear end of the barrel 15 in the non-writing state (FIGS. 1A to 1C). Shallow grooves 75 are formed on the front and back surfaces of the protruding portion 72 (FIGS. 4A, 4D, and 4F).

[0034] A sawtooth knock cam 74 having eight alternating peaks and eight valleys is formed on the tip end surface of the cam cylinder portion 71 (FIGS. 4A to 4C, 4E, and 4F). The knock cam 74 is formed so that the peaks and valleys of the knock cam 74 mesh with the rotating cam 63 (FIGS. 3D and 3E) of the rotor 60. Eight guide protrusions 73 are also evenly arranged on the outer periphery of the cam cylinder portion 71. Each of the guide protrusions 73 fits into either the first guide groove 36 or the second guide groove 37 (FIG. 2F) of the inner shaft 30 and slides back and forth along either the first guide groove 36 or the second guide groove 37.

[0035] (1-5) Non-writing state In the non-writing state shown in FIG. 1C, the refill 50 is biased backward by the knock spring 11, and the rotor 60 and the knock button 70 are also pressed backward. As shown in FIG. 5, which is an enlarged view of the rear end portion of FIG. 1C, at this time, the guide protrusion 73 of the knock button 70 is recessed into the first guide groove 36 or the second guide groove 37 (FIG. 2F) of the inner shaft 30, and the sliding protrusion 67 of the rotor (not shown in FIG. 5) is recessed into the first guide groove 36 (FIG. 2F) of the inner shaft 30. The guide protrusion 73 is in contact with the rear end step 39 of the inner shaft 30, and is prevented from moving further backward. In this state, the ballpoint pen tip 53 is recessed into the inside of the front shaft 40 (FIG. 1C).

[0036] (1-6) Writing condition Next, the ballpoint pen 10 in a writing state will be described with reference to Fig. 6A to Fig. 6C and Fig. 7. Fig. 6A is a front view of the ballpoint pen 10 in a writing state, Fig. 6B is a side view of the ballpoint pen 10 in Fig. 6A, and Fig. 6C is a cross-sectional view taken along line VI-VI in Fig. 6A. Fig. 7 shows an enlarged view of the rear end portion of Fig. 6C.

[0037] When knock button 70 is pressed from the non-writing state shown in Figures 1A to 1C, ballpoint pen tip 53 protrudes from the end of front barrel 40, making writing possible, as shown in Figures 6A to 6C. Before reaching this state, the following events occur inside inner barrel 30.

[0038] First, when the knock button 70 is pressed, the rotor 60 also moves forward with the forward movement of the knock button 70, with the rotating cam 63 meshing with the knock cam 74. At this time, the guide protrusion 73 slides forward along the first guide groove 36 or the second guide groove 37, and at the same time, the sliding protrusion 67 slides forward along the first guide groove 36. Then, when the sliding protrusion 67 leaves the first guide groove 36, the rotating cam 63 rotates along the inclination of the inner cam 35, but the rotation stops when the engaging cam 64 abuts against the inner cam 35 located in the rotation direction. In this state, the rotor 60 is pressed backward from the rear end of the refill 50 by the biasing force of the knock spring 11, and the engaging cam 64 is maintained in engagement with the inner cam 35. This state is shown in FIG. 7.

[0039] At this time, the inclined surface 66 of the rotor 60 that abuts against the rear end of the refill 50 is pressed backward, and receives a force that makes it perpendicular to the axis. This force presses the inclined cam 64A, the cam surface of which is located furthest forward among the engagement cams 64, backward. This causes the rotor 60 to tilt in the direction in which the fulcrum cam 64B is located. Then, the push rod 62 inserted inside the knock button 70 presses the knock button 70 from the inside in this inclined direction, so that the knock button 70 is fixed by being sandwiched between the push rod 62 and the inner wall of the rear end opening 38.

[0040] In this state, the knock button 70 is free relative to the rotor 60, but since it is fixed as described above, even if there is vibration associated with writing, the frictional resistance between the knock button 70 and the rotor 60 prevents the knock button 70 from vibrating.

[0041] When the knock button 70 is pressed again from this writing state, the rotor 60 is moved forward, and each of the engagement cams 64 is released from engagement with the inner cam 35. Then, the rotating cam 63 rotates again along the cam surface of the inner cam 35, and the sliding protrusion 67 fits into the first guide groove 36 in the rotation direction. In this state, the rotor 60 is moved backward by the biasing force of the knock spring 11. Then, when the guide projection 73 abuts against the rear end step 39, the rotor stops moving and returns to the non-writing state shown in Figures 1A to 1C.

[0042] (1-7) Summary of the First Embodiment As described above, the ballpoint pen 10 according to the first embodiment includes a barrel 15, a refill 50 that is housed in the barrel 15 and whose tip appears and disappears from the barrel 15 in response to a knock operation, a knock spring 11 that is interposed between the barrel 15 and the refill 50 and biases the refill 50 rearward, a cam portion 61 that has a cam formed on its rear end surface and is substantially cylindrical in shape, and a pressure rod 62 that protrudes rearward from the cam portion 61 and is rod-shaped with a smaller diameter, and the rotor 60 that abuts against the rear end of the refill 50, and the pressure rod 62 The rotor 60 includes a knock button 70 that is inserted into the internal space and abuts against the rear end of the cam portion 61, and partially protrudes from the rear end of the barrel 15, an inner cam 35 formed on the inner surface near the rear end of the barrel 15, a knock cam 74 formed on the tip surface of the knock button 70, a rotating cam 63 formed on the rear end surface of the rotor 60 and engaging with the knock cam 74, a plurality of engagement cams 64 formed on the outer periphery of the rotating cam 63 and engaging with the inner cam 35, and an inclined surface 66 at the tip surface of the rotor 60 that inclines backward.

[0043] The ballpoint pen 10 of the first embodiment is configured so that, when the rotor 60 is pressed by the knock button 70 and the engagement cam 64 is engaged with the inner cam 35, the refill 50 is urged rearward by the knock spring 11, and the inclined surface 66 is pressed rearward by the rear end of the refill 50, causing the rotor 60 to incline toward the position of the inclined surface 66 closest to the rear relative to the axis, and the pressure rod 62 presses the inner surface of the knock button 70 to fix the knock button 70 to the barrel 15.

[0044] In the ballpoint pen 10 according to the first embodiment, the multiple engagement cams 64 are provided with an inclined cam 64A whose position for engaging with the inner cam 35 is closer to the front than the others and is located on the side of the inclined surface 66 closest to the front, and a fulcrum cam 64B that faces the inclined cam 64A across the axis and whose position for engaging with the inner cam 35 is closer to the rear than the others and is located on the side of the inclined surface 66 closest to the rear. As a result, when the inclined cam 64A engages with the inner cam 35, the rotor 60 is inclined toward the fulcrum cam 64B.

[0045] (2) Second embodiment (2-1) Overall configuration of ballpoint pen 10 The overall configuration of a ballpoint pen 10 of a second embodiment will be described with reference to Fig. 8A to Fig. 8C. Fig. 8A is a front view of the ballpoint pen 10, Fig. 8B is a side view of the ballpoint pen 10 of Fig. 8A, and Fig. 8C is a cross-sectional view taken along line VIII-VIII of Fig. 8A. Figs. 8A to 8C show the ballpoint pen 10 in a non-writing state.

[0046] As shown in Figures 8A and 8B, the appearance of the ballpoint pen 10 of the second embodiment is not different from that of the ballpoint pen 10 of the first embodiment. The ballpoint pen 10 of the second embodiment has the same configuration as the ballpoint pen 10 of the first embodiment, except for the configuration of the rotor 60 shown in Figure 8C. Hereinafter, the overall configuration of the ballpoint pen 10 and the structures of the inner shaft 30 and the knock button 70 are the same as those of the first embodiment, so a description thereof will be omitted.

[0047] (2-2) Rotor The structure of the rotor 60 used in the ballpoint pen 10 of this embodiment will be described with reference to Figures 9A to 9G. Figure 9A is a front view of the rotor 60, Figure 9B is a side view of the rotor 60, Figure 9C is a front perspective view of the rotor 60, Figure 9D is a rear perspective view of the rotor 60, Figure 9E is a plan view of the rotor 60, Figure 9F is a bottom view of the rotor 60, and Figure 9G is a cross-sectional view taken along line IX-IX of Figure 9A.

[0048] The rotor 60 is composed of a generally cylindrical cam portion 61 on which a cam is formed, and a columnar pressing rod 62 that has a smaller diameter than the cam portion 61 and protrudes to the tip. A sawtooth-like rotating cam 63 with eight peaks and eight valleys alternately and evenly arranged is formed on the tip surface of the cam portion 61 (Fig. 9D). Meanwhile, the rear end edge of the cam portion 61 forms a flange 68 with an increased outer diameter. On the inner peripheral surface of the cam portion 61, four inner peripheral ribs 65 extending in the axial direction are evenly arranged (Figs. 9C, 9F, and 9G).

[0049] Four sliding ridges 67 extending in the axial direction are evenly arranged on the outer peripheral surface of the cam portion 61. An engagement cam 64 is formed at the tip of the sliding ridges 67 as an inclined surface whose height increases from right to left when viewed from the front. The sliding ridges 67 are formed at a position where the inclination of the engagement cam 64 coincides with the inclination of the rotating cam 63 (FIGS. 9A, 9B, and 9D). The outer peripheral surface of the sliding ridges 67 coincides with the outer peripheral surface of the flange 68 (FIGS. 9A to 9D, and 9E). The sliding ridges 67 are recessed into the first guide groove 36 (FIG. 2F) of the inner shaft 30, and slide back and forth along the first guide groove 36.

[0050] Of the four engagement cams 64, one has a cam surface located closer to the tip than the others, and is referred to as inclined cam 64A (Figs. 9B, 9D, 9E). Also, of the four engagement cams 64, the other has a cam surface located closer to the rear end than the others, and is referred to as fulcrum cam 64B (Figs. 9A, 9B, 9D, 9E). The cam surface of fulcrum cam 64B coincides with the cam surface of rotating cam 63 (Figs. 9B, 9E). The cam surfaces of the engagement cams 64 and the engagement cams 64 other than fulcrum cam 64B are located closer to the tip than the cam surface of rotating cam 63 (Figs. 9A, 9B, 9D).

[0051] The tip surface of the rotor 60 is an inclined surface 66 that is inclined backward (FIGS. 9B, 9C, 9F, and 9G). Specifically, the side of the inclined surface 66 that is closest to the front corresponds to the side where the inclined cam 64A is located. Also, the side of the inclined surface 66 that is closest to the rear corresponds to the side where the fulcrum cam 64B is located (FIGS. 9B and 9G). Furthermore, a front protrusion 69 protrudes in the tip direction from the side of the inclined surface 66 that is closest to the rear.

[0052] (2-3) Non-writing state In the non-writing state shown in FIG. 8C, the refill 50 is biased backward by the knock spring 11, and the rotor 60 and the knock button 70 are also pressed backward. As shown in FIG. 10, which is an enlarged view of the rear end portion of FIG. 8C, at this time, the guide protrusion 73 of the knock button 70 is recessed into the first guide groove 36 or the second guide groove 37 (FIG. 2F) of the inner shaft 30, and the sliding protrusion 67 of the rotor (not shown in FIG. 5) is recessed into the first guide groove 36 (FIG. 2F) of the inner shaft 30. The guide protrusion 73 is in contact with the rear end step 39 of the inner shaft 30, and is prevented from moving further backward. In this state, the ballpoint pen tip 53 is recessed into the inside of the front shaft 40 (FIG. 8C).

[0053] (2-4) Writing condition Next, the ballpoint pen 10 in a writing state will be described with reference to Figures 11A to 11C and 12. Figure 11A is a front view of the ballpoint pen 10 in a writing state, Figure 11B is a side view of the ballpoint pen 10 in Figure 11A, and Figure 11C is a cross-sectional view taken along line XI-XI in Figure 11A. Figure 12 shows an enlarged view of the rear end portion of Figure 12C.

[0054] When knock button 70 is pressed from the non-writing state shown in Figures 8A to 8C, ballpoint pen tip 53 protrudes from the end of front barrel 40, making writing possible, as shown in Figures 11A to 11C. Until this state is reached, the following events occur inside inner barrel 30.

[0055] First, when the knock button 70 is pressed, the rotor 60 also moves forward with the rotation cam 63 meshing with the knock cam 74 as the knock button 70 moves forward. At this time, the guide protrusion 73 slides forward along the first guide groove 36 or the second guide groove 37, and at the same time, the sliding protrusion 67 slides forward along the first guide groove 36. Then, when the sliding protrusion 67 leaves the first guide groove 36, the rotation cam 63 rotates along the inclination of the inner cam 35, but the rotation stops when the engagement cam 64 abuts against the inner cam 35 located in the rotation direction. In this state, the rotor 60 is pressed backward from the rear end of the refill 50 by the biasing force of the knock spring 11, and the engagement cam 64 is maintained in engagement with the inner cam 35. This state is shown in FIG. 12.

[0056] At this time, the inclined surface 66 of the rotor 60 that abuts against the rear end of the refill 50 is pressed backward, and receives a force perpendicular to the axis. At this time, the rear end of the refill 50, the side located on the side of the fulcrum cam 64B, receives a reaction force to the right as viewed from FIG. 12 by the abutting front protrusion 69. This reaction strengthens the force that presses the rear end of the refill 50, the side located on the side of the inclined cam 64A, backward. This force presses the inclined cam 64A, the cam surface of which is located most forward, of the engagement cam 64, backward. This causes the rotor 60 to tilt toward the position of the fulcrum cam 64B. Then, the push rod 62 inserted inside the knock button 70 presses the knock button 70 from the inside in this inclined direction, and the knock button 70 is fixed by being sandwiched between the push rod 62 and the inner wall of the rear end opening 38.

[0057] In this state, the knock button 70 is free relative to the rotor 60, but since it is fixed in place as described above, vibrations that accompany writing are prevented.

[0058] When the knock button 70 is pressed again from this writing state, the rotor 60 is moved forward, and each of the engagement cams 64 is released from engagement with the inner cam 35. Then, the rotating cam 63 rotates again along the cam surface of the inner cam 35, and the sliding protrusion 67 fits into the first guide groove 36 in the rotation direction. In this state, the rotor 60 is moved backward by the biasing force of the knock spring 11. Then, when the guide projection 73 abuts against the rear end step 39, the rotor stops moving and returns to the non-writing state shown in Figures 8A to 8C.

[0059] (2-5) Summary of the Second Embodiment As described above, the ballpoint pen 10 according to the second embodiment includes a barrel 15, a refill 50 that is housed in the barrel 15 and whose tip appears and disappears from the barrel 15 in response to a knock operation, a knock spring 11 that is interposed between the barrel 15 and the refill 50 and that urges the refill 50 rearward, a cam portion 61 that has a cam formed on its rear end surface and is substantially cylindrical in shape, and a pressure rod 62 that protrudes rearward from the cam portion 61 and is rod-shaped with a smaller diameter, and the rotor 60 that abuts against the rear end of the refill 50, and the pressure rod 62 The rotor 60 includes a knock button 70 that is inserted into the internal space and abuts against the rear end of the cam portion 61, and partially protrudes from the rear end of the barrel 15, an inner cam 35 formed on the inner surface near the rear end of the barrel 15, a knock cam 74 formed on the tip surface of the knock button 70, a rotating cam 63 formed on the rear end surface of the rotor 60 and engaging with the knock cam 74, a plurality of engagement cams 64 formed on the outer periphery of the rotating cam 63 and engaging with the inner cam 35, and an inclined surface 66 at the tip surface of the rotor 60 that inclines backward.

[0060] The ballpoint pen 10 of the second embodiment is configured so that, when the rotor 60 is pressed by the knock button 70 and the engagement cam 64 is engaged with the inner cam 35, the refill 50 is urged rearward by the knock spring 11, and the inclined surface 66 is pressed rearward by the rear end of the refill 50, causing the rotor 60 to incline toward the position of the inclined surface 66 closest to the rear relative to the axis, and the pressing rod 62 presses the inner surface of the knock button 70 to fix the knock button 70 to the barrel 15.

[0061] In the ballpoint pen 10 according to the second embodiment, the multiple engagement cams 64 are provided with an inclined cam 64A whose position for engaging with the inner cam 35 is closer to the front than the others and is located on the side of the inclined surface 66 closest to the front, and a fulcrum cam 64B that faces the inclined cam 64A across the axis and whose position for engaging with the inner cam 35 is closer to the rear than the others and is located on the side of the inclined surface 66 closest to the rear. As a result, when the inclined cam 64A engages with the inner cam 35, the rotor 60 is inclined toward the fulcrum cam 64B.

[0062] In the ballpoint pen 10 according to the second embodiment, a front projection 69 that projects forward is further formed on the side of the inclined surface 66 on which the fulcrum cam 64B is provided.

[0063] In both the first and second embodiments, the knock button 70 and the rotor 60 are fixed to each other. However, even if the knock button 70 is fixed to the guide protrusion 73 of the knock button 70 and the second guide groove 37 of the inner shaft 30, the effect of preventing the knock button 70 from vibrating during writing can be obtained. [Industrial Applicability]

[0064] The embodiments of the present disclosure can be used in a knock-type ballpoint pen. [Explanation of symbols]

[0065] 10 Ballpoint pen 11 Knock spring 12 Gasket 15 Shaft tube 20 outer shaft 21 grip 22 male thread 30 inner shaft 31 exposed portion 32 insertion portion 33 Clip 34 Guide ridge 35 Inner cam 36 First guide groove 37 Second guide groove 38 Rear end opening 39 Rear step 40 front shaft 41 large diameter portion 42 female thread portion 43 Tapered portion 46 Tip opening 50 Refills 51 Ink containing tube 51A Ink 51B Follower 52 Joint 52A Rear connection part 52B Front connection part 53 Ballpoint pen tip 53A Holder 53B Writing ball 60 rotor 61 cam portion 62 pressure rod 63 Rotating cam 64 Engaging cam 64A Inclined cam 64B Fulcrum cam 65 Inner rib 66 Inclined surface 67 Sliding ridge 68 Flange 69 Forward projection 70 knock button 71 cam barrel 72 protrusion 73 Guide protrusion 74 Knock cam 75 Groove

Claims

1. A shaft cylinder, a refill that is accommodated in the barrel and whose tip appears and disappears from the barrel in response to a knocking motion; A knock spring is interposed between the barrel and the refill and biases the refill rearward. a rotor having a cam portion having a substantially cylindrical shape with a cam formed on a rear end surface thereof and a pressure rod having a smaller diameter and protruding rearward from the cam portion, the rotor being in contact with the rear end of the refill; a knock button that is inserted into the internal space and abuts against the rear end of the cam portion and partially protrudes from the rear end of the barrel; an inner peripheral cam formed on an inner surface of the barrel near a rear end thereof; A knock cam formed on a tip surface of the knock button; a rotating cam formed on a rear end surface of the rotor and meshing with the knock cam; a plurality of engagement cams formed on an outer circumferential side of the rotating cam and meshing with the inner circumferential cam; a rearwardly inclined surface which is a tip end surface of the rotor; Equipped with In a state where the rotor is pressed by the knock button and the engagement cam is engaged with the inner circumferential cam, The refill is biased rearward by the knock spring, When the inclined surface is pressed backward by the rear end of the refill, the rotor is inclined toward the rearmost position of the inclined surface relative to the axis, The pressing rod is formed so as to press the inner peripheral surface of the knock button to fix the knock button to the barrel. Ballpoint pen.

2. The plurality of engagement cams include: an inclined cam that is located on the side of the inclined surface closest to the front and that engages with the inner circumferential cam at a position closer to the front than the other inclined surfaces; a fulcrum cam that faces the inclined cam across an axis, has a position that engages with the inner circumferential cam closer to the rear than the other fulcrum cams, and is located on the side of the inclined surface that is closest to the rear; is established, The ballpoint pen according to claim 1 , wherein the inclined cam engages with the inner circumferential cam, causing the rotor to incline toward the fulcrum cam.

3. 3. The ballpoint pen according to claim 2, wherein a front protrusion that protrudes forward is formed on a side of the inclined surface where the fulcrum cam is provided.

Images