Knock-type writing instrument

Abstract

To provide a knock type writing instrument having a fitting member rotatably fitted to a knock member about a central axis of the knock member, and capable of performing a reliable knock operation.SOLUTION: A knock type writing instrument 1 comprises: a rotor 40, a knock member 30 pressing the rotor 40 forward and having a locking protrusion 31 on an outer peripheral surface; a fitting member 50 fitted to the knock member 30 so as to be rotatable about a central axis of the knock member 30 and provided with a connecting portion 51 on its outer surface; a regulating portion 60 regulating rotation of the fitting member 50; and a barrel 4 provided with a plurality of outer cams 20 arranged along a circumferential direction and cooperating with the rotor 40, and having the locking protrusion 31 arranged between the plurality of outer cams 20. When the connecting portion 51 of the fitting member 50 is rotated until it abuts against the regulating portion 60 in a non-writing state, the locking protrusion 31 and the outer cam 20 do not abut against each other.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

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

[0003] Patent Document 1 discloses a structure for preventing rotation of a fitting member (corresponding to the knock member in Patent Document 1) that fits with the knock member and has a clip, about the central axis of the knock member. [Prior art documents] [Patent documents]

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

[0005] In general, it is desirable that parts assembled by fitting or the like for the purpose of fixing should not move relatively due to an external force, that is, should not come loose or become displaced. Problems caused by the relative movement of the knock member and the fitting member will be described with reference to Figures 5 to 7.

[0006] Fig. 5 is a cross-sectional view of a conventional knock type writing instrument 100 corresponding to Fig. 2 described later. The knock type writing instrument 100 has a knock mechanism 110. The knock mechanism 110 has an outer cam 120, a cylindrical knock member 130, a rotor 140, and a fitting member 150 equipped with a connection portion 151 for connecting a clip.

[0007] FIG. 6 is a schematic diagram showing the relationship between the knock member 130, the fitting member 150, and the restricting portion 160 in a conventional knock type writing instrument 100. The restricting portion 160 is configured as a side surface of a notch portion 108 that is cut forward from the rear end surface of the rear barrel 103. FIG. 6(A) shows the knock type writing instrument 100 in a non-writing state, and FIG. 6(B) shows the knock type writing instrument 100 in a state during a knock operation. The connecting portion 151 is configured to move in the front-rear direction within the notch portion 108 by the knock operation. FIG. 7 is another schematic diagram showing the relationship between the knock member 130, the fitting member 150, and the restricting portion 160 in a conventional knock type writing instrument 100.

[0008] 6 and 7 are schematic diagrams showing the positional relationship of the knock mechanism 110, and show the positions of the locking protrusion 131 of the knock member 130 and the inner cam 141 of the rotor 140, which will be described later, relative to a partial circumferential development of the outer cam 120 and the regulating portion 160. In the drawings, the lower side is the front of the knock type writing instrument 100, and the upper side is the rear of the knock type writing instrument 100.

[0009] In detail, outer cams 120, which are cam protrusions constituting a part of the knock mechanism 110, are provided at equal intervals along the circumferential direction in front of the restricting portion 160 of the rear axle 103. Adjacent outer cams 120 define a guide groove 121 extending in the front-rear direction. On the outer peripheral surface on the front side of the knock member 130, locking protrusions 131 are provided at equal intervals in the circumferential direction. Each of the locking protrusions 131 is disposed in the guide groove 121 between adjacent outer cams 120. Each of the locking protrusions 131 is configured to move in the front-rear direction within the guide groove 121 by a knock operation. A cam surface 132 is formed on the front end surface of the knock member 130.

[0010] The fitting member 150 is fitted to the outer peripheral surface of the rear end of the knock member 130. The inner cams 141, which are protrusions extending in the front-rear direction, are provided on the outer peripheral surface of the rotor 140 at equal intervals in the circumferential direction. For convenience, the inner cams 141 are hatched in the figure, but do not represent a cross section. In the knock-type writing instrument 100 in the non-writing state as shown in FIG. 6(A), each of the inner cams 141 is disposed in the guide groove 121 of the outer cam 120. The rotor 140 has a cam receiving surface 142 that cooperates with the cam surface 132 of the knock member 130 and has a complementary shape. The rotor 140 is given a rotational force by the cooperation of the cam surface 132 of the knock member 130 and the cam receiving surface 142 of the rotor 140, and rotates around the central axis. The rotor 140 also cooperates with the outer cam 120, and contributes to switching between the writing state and the non-writing state. The restriction portion 160 is composed of two side surfaces that are inclined toward each other toward the front in FIG. 6, which shows the restriction portion 160 developed in the circumferential direction.

[0011] 6A, the rotor 140 is biased backward, so that the cam surface 132 of the knock member 130 and the cam receiving surface 142 of the rotor 140 cooperate with each other, and a biasing force is applied to rotate the knock member 130 to the right and the rotor 140 to the left in the figure. The rotation of the knock member 130 is restricted by the engagement protrusion 131 abutting against the side surface of one of the outer cams 120, and the rotation of the rotor 140 is restricted by the engagement protrusion 131 abutting against the side surface of the other outer cam 120. At this time, the engagement protrusion 131 and the other outer cam 120 are separated by a distance d1 along the circumferential direction. Also, the connection portion 151 and the restriction portion 160 are separated by a minimum distance d2 along the circumferential direction. The distance d1 is set to be smaller than the distance d2.

[0012] In Fig. 6(A), the center line c1 of the cutout portion 108 coincides with the center line c2 of the connection portion 151. When a knock operation is performed in this state, the center lines c1 and c2 maintain a substantially coincident state (Fig. 6(B)).

[0013] 6(A), when the fitting member 150 is gripped and rotated against the biasing force that rotates the knock member 130, i.e., to the left in the figure, the knock member 130 and the fitting member 150 rotate together around the central axis of the knock member 130. The rotation of the knock member 130 and the fitting member 150 is restricted by the engagement protrusion 131 of the knock member 130 abutting against the side surface of the other outer cam 120 (FIG. 7(A)). At this time, the amount of rotation of the knock member 130 and the fitting member 150, i.e., the rotation angle, is the above-mentioned distance d1 when expressed as the distance from the center line c1 in FIG. 7.

[0014] When further force is applied to fitting member 150 from the state shown in Fig. 7(A) and fitting member 150 is rotated around the central axis of knock member 130 relative to knock member 130, only fitting member 150 rotates. The rotation of fitting member 150 is restricted by connection portion 151 abutting against restriction portion 160 (Fig. 7(B)). At this time, the rotation angle of fitting member 150, expressed as the distance from center line c1 in Fig. 7, is the above-mentioned distance d2.

[0015] When the applied force is released from the state shown in Fig. 7(B), the knock member 130 rotates in the return direction due to the biasing force via the rotor 140, and stops when the locking protrusion 131 abuts against the side surface of one of the outer cams 120. On the other hand, the fitting member 150 rotates in the same manner while maintaining its relative position with the knock member 130, and then stops (Fig. 7(C)). Therefore, the rotation angle of the fitting member 150, expressed as the distance from the center line c1 in Fig. 7, is the distance d2-d1.

[0016] When a knock operation is performed in this state, since the restricting portion 160 has an inclined side surface, as shown in Fig. 7(D), the front end portion of the connecting portion 151 interferes with the restricting portion 160 at point X. As a result, not only is the knock operation hindered, but there is also a risk that the connecting portion 151 and the restricting portion 160 will be locked together and the knock member 130 will not return to its original position. Therefore, there is a risk that the knock operation will not be performed reliably in the knock-type writing instrument 100. This problem is more pronounced when the fitting member 150 is fitted more firmly into the knock member 130.

[0017] An object of the present invention is to provide a knock-type writing instrument that has a fitting member that fits rotatably around the central axis of the knock member, and that enables a reliable knock operation. [Means for solving the problem]

[0018] According to one aspect of the present invention, there is provided a knock-type writing instrument comprising a rotor, a knock member which presses the rotor forward and has a locking protrusion on its outer peripheral surface, a fitting member which fits rotatably around the central axis of the knock member and has a regulating protrusion on its outer surface, a regulating portion which regulates the rotation of the fitting member, and a shaft cylinder which is provided with a plurality of cam protrusions which are arranged circumferentially and cooperate with the rotor, and in which the locking protrusion is arranged between the plurality of cam protrusions, and which is configured so that when the regulating protrusion of the fitting member is rotated until it abuts against the regulating portion in a non-writing state, the locking protrusion and the cam protrusion do not abut against each other.

[0019] The fitting member may be fitted to a rear end portion of the knock member. The fitting member may have a clip. Effect of the Invention

[0020] According to the aspects of the present invention, a common effect is achieved in that a knock-type writing instrument that can perform a reliable knock operation is provided, which is equipped with an engaging member that is rotatably engaged with the knock member around the central axis of the knock member. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a vertical cross-sectional view of a knock-type writing instrument according to an embodiment of the present invention in a writing state. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 3 is a schematic diagram showing the relationship between the knock member, the fitting member, and the restricting portion. [Figure 4] FIG. 4 is another schematic diagram showing the relationship between the knock member, the fitting member, and the restricting portion. [Diagram 5] FIG. 5 is a cross-sectional view of a conventional knock-type writing instrument corresponding to FIG. [Figure 6] FIG. 6 is a schematic diagram showing the relationship between a knock member, a fitting member, and a restricting portion in a conventional knock-type writing instrument. [Figure 7] FIG. 7 is another schematic diagram showing the relationship between the knock member, the fitting member, and the restricting portion in a conventional knock-type writing instrument. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] 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.

[0023] FIG. 1 is a vertical cross-sectional view of a knock-type writing instrument 1 according to an embodiment of the present invention in a writing state, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

[0024] The knock-type writing instrument 1 has a barrel 4 formed in a cylindrical shape and equipped with a front shaft 2 and a rear shaft 3, a refill 6 which is a writing body arranged in the barrel 4 and equipped with a writing part 5 at one end, a spring 7 which biases the refill 6 backward, and a knock mechanism 10 arranged at the rear end of the barrel 4. The knock mechanism 10 has an outer cam 20 (FIG. 2), a cylindrical knock member 30, a rotor 40, and a fitting member 50 equipped with a connecting part 51 which connects a clip 52. The connecting part 51 constitutes a restricting protrusion. A notch 8 which is cut forward is formed on the rear end surface of the rear shaft 3, and a side surface of the notch 8 constitutes a restricting part 60. The connecting part 51 is configured to move in the front-rear direction within the notch 8 by a knock operation. In this specification, in the axial direction of the knock-type writing instrument 1, the writing part 5 side is defined as the "front" side, and the opposite side to the writing part 5 side is defined as the "rear" side.

[0025] Fig. 3 is a schematic diagram showing the relationship between the knock member 30, the fitting member 50, and the regulating portion 60, and Fig. 4 is another schematic diagram showing the relationship between the knock member 30, the fitting member 50, and the regulating portion 60. That is, Figs. 3 and 4 are schematic diagrams showing the positional relationship of the knock mechanism 10, and show the positions of the locking protrusion 31 of the knock member 30 and the inner cam 41 of the rotor 40, which will be described later, relative to a partial circumferential development of the outer cam 20 and the regulating portion 60. In the figures, 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.

[0026] In detail, outer cams 20, which are cam protrusions constituting a part of the knock mechanism 10, are provided at equal intervals along the circumferential direction in front of the restricting portion 60 of the rear axle 3. Adjacent outer cams 20 define a guide groove 21 extending in the front-rear direction. On the outer peripheral surface on the front side of the knock member 30, locking protrusions 31 are provided at equal intervals in the circumferential direction. Each of the locking protrusions 31 is disposed in the guide groove 21 between adjacent outer cams 20. Each of the locking protrusions 31 is configured to move in the front-rear direction within the guide groove 21 by a knock operation. A cam surface 32 is formed on the front end surface of the knock member 30.

[0027] The fitting member 50 is fitted to the outer peripheral surface of the rear end of the knock member 30. The inner cams 41, which are protrusions extending in the front-rear direction, are provided on the outer peripheral surface of the rotor 40 at equal intervals in the circumferential direction. For convenience, the inner cams 41 are hatched in the figure, but do not represent a cross section. In the knock-type writing instrument 1 in the non-writing state as shown in FIG. 3, each of the inner cams 41 is disposed in the guide groove 21 of the outer cam 20. The rotor 40 has a cam receiving surface 42 that cooperates with the cam surface 32 of the knock member 30 and has a complementary shape. 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 42 of the rotor 40, and rotates around the central axis. The rotor 40 also cooperates with the outer cam 20, and contributes to switching between the writing state and the non-writing state. The restriction portion 60 is composed of two side surfaces that are inclined toward each other toward the front in FIG. 3, which shows the restriction portion 60 developed in the circumferential direction.

[0028] 3, the rotor 40 is biased backward by the spring 7 via the refill 6, so that the cam surface 32 of the knock member 30 and the cam receiving surface 42 of the rotor 40 cooperate with each other, and a biasing force is applied to rotate the knock member 30 to the right and the rotor 40 to the left in the figure. The rotation of the knock member 30 is restricted by the engagement protrusion 31 abutting against the side surface of one of the outer cams 20, and the rotation of the rotor 40 is restricted by the engagement protrusion 31 abutting against the side surface of the other outer cam 20. At this time, the engagement protrusion 31 and the other outer cam 20 are separated by a distance D1 along the circumferential direction. Also, the connection portion 51 and the restriction portion 60 are separated by a minimum distance D2 along the circumferential direction. The distance D1 is set to be greater than the distance D2.

[0029] 3, the center line C1 of the cutout portion 8 coincides with the center line C2 of the connection portion 51. When a knocking operation is performed in this state, the center lines C1 and C2 maintain their approximately coincident state.

[0030] 3, when the fitting member 50 is gripped and rotated against the biasing force that rotates the knock member 30, i.e., to the left in the figure, the knock member 30 and the fitting member 50 rotate together around the central axis of the knock member 30. The rotation of the knock member 30 and the fitting member 50 is restricted by the connection portion 51 coming into contact with the restriction portion 60 (FIG. 4). At this time, the amount of rotation of the knock member 30 and the fitting member 50, i.e., the rotation angle, is the above-mentioned distance D2, as shown in terms of the distance from the center line C1 in FIG. 4. On the other hand, the locking protrusion 31 and the other outer cam 20 are separated by the distance D1-D2.

[0031] Even if further force is applied to the fitting member 50 from the state shown in Fig. 4, the connecting portion 51 abuts against the restricting portion 60, so that the fitting member 50 cannot be rotated around the central axis of the knock member 30 relative to the knock member 30. Furthermore, when the applied force is released, the knock member 30 and the fitting member 50 rotate due to the biasing force via the rotor 40, and can be returned to the original state (Fig. 3). In short, the knock member 30 and the fitting member 50 will not be displaced. Therefore, when a knock operation is performed in this state, interference between the front end of the connecting portion 51 and the restricting portion 60 cannot occur as shown in Fig. 7(D), and a reliable knock operation can be performed.

[0032] In the conventional knock-type writing implement described above with reference to Figs. 5 to 7, it was common sense to make the clearance between the locking protrusion 131 and the outer cam 120, specifically the distance d1, smaller in order to prevent the knock member 130 from rotating or moving in the circumferential direction and rattling when not in use. Therefore, the clearance between the connection portion 151 and the regulating portion 160, specifically the distance d2, is larger than the distance d1. On the other hand, in the above-described embodiment, contrary to common sense, the distance D1 in Fig. 3 is made larger than the distance D2. Note that the distances D1 and D2 may be equal.

[0033] The above-mentioned configuration is particularly effective in cases where the fitting member needs to be tightly fitted to the knock member. For example, if the force required to remove the fitting member is set to 50 N to prevent the fitting member from coming off the knock member, it is difficult to rotate the fitting member relative to the knock member. However, once the fitting member is rotated, it is also difficult to return it to its original position, which makes the above-mentioned problem more likely to occur. In such cases, the problem of the knock operation not being performed reliably can be prevented by configuring the distance D1 in FIG. 3 to be greater than the distance D2.

[0034] In the above-described embodiment, the fitting member 50 is configured to have the clip 52 provided via the connection portion 51, but it may be configured so that a simple protrusion corresponding to the connection portion moves in the front-rear direction within the cutout portion without having a clip. The fitting member may be fitted to the central portion in the axial direction, not the rear end portion of the knock member, and in this case, the cutout portion may be a rectangular opening portion provided on the side of the barrel. The restricting portion is an inclined side surface of the cutout portion, but it may be configured arbitrarily as long as it allows the connection portion to move in the front-rear direction and restricts its rotation. For example, the restricting portion may be a side surface that extends along the axial direction without being inclined. In short, the fitting member, the restricting portion, and even the restricting protrusion may be configured arbitrarily as long as it is configured so that the locking protrusion portion and the outer cam (cam protrusion) do not come into contact with each other when the connection portion (restricting protrusion) of the fitting member is rotated until it comes into contact with the restricting portion in a non-writing state.

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

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

[0037] 1. Knock-type writing implement 2 front axle 3 rear axle 4 shaft cylinder 5 Writing section 6 Refills 7. Spring 8 Cutout 10 Knock mechanism 20 Outer Cam 21 Guide groove 30 Knock parts 31 Locking protrusion 32 Cam surface 40 Rotor 41 Inner cam 42 Cam receiving surface 50 Fitting member 51 Connection 52 clips 60 Regulatory Department

Claims

1. A rotor; a knock member that presses the rotor forward and has an engaging protrusion on an outer circumferential surface; a fitting member that is fitted to the knock member so as to be rotatable about a central axis of the knock member and has a restricting protrusion on an outer surface thereof; a restricting portion that restricts rotation of the fitting member; and a shaft cylinder that is provided with a plurality of cam protrusions that are arranged along a circumferential direction and cooperate with the rotor, and the locking protrusion portion is arranged between the plurality of cam protrusions, A knock-type writing instrument characterized in that, when the regulating protrusion of the engaging member is rotated relative to the knock member until it abuts against the regulating portion in a non-writing state, the locking protrusion portion and the cam protrusion are configured not to abut against each other.

2. 2. The knock type writing implement according to claim 1, wherein the fitting member is fitted to the rear end of the knock member.

3. 3. The knock-type writing implement according to claim 1, wherein the fitting member has a clip, and the restricting projection is a connection portion that connects the clip and the fitting member.

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