Notebook

Abstract

To make a moving distance of a writing member sufficiently larger than a moving distance of a knock member.SOLUTION: A writing instrument 10 includes a barrel 20, a writing member 12, and a retractable mechanism 60. The retractable mechanism includes a knock member 61 and a stroke increasing mechanism 65. The stroke increasing mechanism includes a rear member 70 having a first cam surface 72, an intermediate member 80 having a second cam surface 82 and a third cam surface 84, and a front member 90 having a fourth cam surface 92. In the retracted state, the first cam surface, the second cam surface, the third cam surface, and the fourth cam surface extend in a direction inclined with respect to an axial direction da and a first direction d1 perpendicular to a central axis as they extend from the rear toward the front so that they extend from one side to the other side in the first direction. When the rear member moves forward, the intermediate member rotates in a circumferential direction dc with respect to the barrel and moves forward by a distance greater than the axial movement distance of the rear member, and the front member moves forward by a distance greater than the axial movement distance of the intermediate member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a writing instrument.

Background Art

[0002] Conventionally, in a writing instrument including a barrel, a writing member disposed within the barrel, and an extending and retracting mechanism that causes the writing member to extend and retract in response to an operation of a knock member, when the knock member is operated, the writing member is moved forward by a distance greater than the moving distance of the knock member.

[0003] Patent Document 1 describes a writing instrument including a first cam, a second cam, and a barrel. In the writing instrument of Patent Document 1, in the retracted state, by pressing the first cam forward by a knock, the first cam moves forward while rotating with respect to the barrel. At this time, the first engaging surface of the first cam inclined with respect to the longitudinal direction and the second engaging surface of the second cam rotate with respect to each other, and the second cam moves forward by a distance longer than the moving distance of the first cam. As a result, the pen tip moves forward by a distance greater than the moving distance of the first cam forward by the knock.

[0004] Patent Document 2 describes a knock-type writing instrument including a linear cam, an extending cam, and a knock cam. In the knock-type writing instrument of Patent Document 2, when the linear cam advances by a knock, the extending cam moves by a distance greater than the moving distance of the linear cam. Further, the knock cam moves by a distance greater than the moving distance of the extending cam. Therefore, the knock cam moves significantly compared to the moving distance of the linear cam by the knock. As a result, the pen tip moves forward by a distance greater than the moving distance of the linear cam forward by the knock.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] In the writing instruments described in Patent Documents 1 and 2, it was not possible to sufficiently increase the ratio (magnification) of the forward movement distance of the pen tip to the forward movement distance of the knocking mechanism operated directly by the user.

[0007] This invention was made with these points in mind, and aims to make the travel distance of the writing member sufficiently larger than the travel distance of the knocking member. [Means for solving the problem]

[0008] The writing instrument according to the present invention is [1] A writing instrument comprising a barrel having a central axis and a front end opening, a writing member disposed inside the barrel, and a retractable mechanism for extending and retracting the tip of the writing member from the front end opening, The aforementioned appearance / disappearance mechanism is, A knocking member that can be pressed forward by the user, The device includes a stroke increasing mechanism that, when the knocking member is pressed forward, moves the writing member forward by a distance greater than the axial travel distance of the knocking member. The stroke increasing mechanism is, A rear member having a first cam surface facing forward, An intermediate member positioned in front of the aforementioned rear member, having a second cam surface facing rear and a third cam surface facing forward, It comprises a front member positioned in front of the intermediate member and having a fourth cam surface facing rear, In the immersed state of the writing instrument, the first cam surface, the second cam surface, the third cam surface, and the fourth cam surface all extend in a direction inclined with respect to the axial direction and the first direction, such that they move from one side of the first direction perpendicular to the central axis to the other side as they move from rear to front. The writing instrument is such that when the rear member moves forward, the intermediate member rotates circumferentially with respect to the barrel and moves forward by a distance greater than the axial movement distance of the rear member, and the front member moves forward by a distance greater than the axial movement distance of the intermediate member.

[0009] The writing instrument according to the present invention is [2] The stroke increasing mechanism has a first groove provided on the inner circumferential surface of the shaft cylinder, The first groove portion has a straight portion extending in the axial direction, The rear member is the writing instrument described in [1], having a first projection located within the first groove.

[0010] The writing instrument according to the present invention is [3] The first groove has an inclined portion extending forward from the front end of the straight portion, The inclined portion extends in a direction inclined with respect to both the axial and circumferential directions, as described in [2].

[0011] The writing instrument according to the present invention is [4] The rear surface of the inclined portion is provided with a stopper, which is the writing instrument described in [3].

[0012] The writing instrument according to the present invention is [5] The stroke increasing mechanism has a second groove provided on the inner circumferential surface of the shaft cylinder, The second groove portion has a main portion that extends in a direction inclined with respect to both the axial and circumferential directions, The intermediate member is a writing instrument according to any one of [1] to [4], having a second projection located within the second groove.

[0013] The writing instrument according to the present invention is [6] The second groove has an extension that extends rearward from the rear end of the main portion, The writing instrument according to [5], wherein the angle between the direction in which the extension extends and the axial direction is smaller than the angle between the direction in which the main part extends and the axial direction.

[0014] The writing instrument according to the present invention is [7] The stroke increasing mechanism has a third groove portion provided on the inner peripheral surface of the shaft cylinder, The third groove portion extends in the axial direction, The front member has a third protrusion portion located in the third groove portion. The writing instrument according to any one of [1] to [6]. [Advantages of the Invention]

[0015] According to the present invention, the moving distance of the writing member can be made sufficiently larger than the moving distance of the knock member. [Brief Description of the Drawings] <{

[0016] [Figure 1] FIG. 1 is a perspective view showing a writing instrument in a submerged state, cut along the central axis of the shaft cylinder. [Figure 2] FIG. 2 is a longitudinal sectional view showing the writing instrument in a submerged state. [Figure 3] FIG. 3 is a perspective view showing the writing instrument of FIG. 1 in a protruding state, cut along the central axis of the shaft cylinder. [Figure 4] FIG. 4 is a longitudinal sectional view showing the writing instrument in a protruding state. [Figure 5] FIG. 5 is an exploded perspective view of the writing instrument. [Figure 6] FIG. 6 is a perspective view showing the main body portion of the shaft cylinder of the writing instrument, cut along the central axis. [Figure 7] FIG. 7 is a diagram for explaining a part of the structure and operation of the stroke increasing mechanism of the writing instrument. [Figure 8] FIG. 8 is a diagram for explaining a part of the structure and operation of the stroke increasing mechanism. [Embodiments for Carrying Out the Invention]

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that, for the sake of illustration and ease of understanding, the scale and aspect ratios of the drawings accompanying this specification have been appropriately altered and exaggerated from those of the actual objects.

[0018] Furthermore, terms used in this specification to specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "identical," as well as values ​​for length and angle, shall not be strictly interpreted, but shall be interpreted to include a range that allows for the expectation of similar functionality.

[0019] In this specification, the direction in which the central axis A of the writing instrument 10 extends is defined as the axial direction da, the direction perpendicular to the axial direction da is defined as the radial direction, and the direction along the circumference around the central axis A is defined as the circumferential direction dc. Along the axial direction da, the pen tip side is defined as the front, and the side opposite the pen tip is defined as the rear. Along the radial direction, the side approaching the central axis A is defined as the inward or inward direction, and the side moving away from the central axis A is defined as the outward or outward direction.

[0020] Figure 1 is a diagram illustrating one embodiment of the present invention, showing a perspective view of the writing instrument 10 in an immersed state, with the barrel 20 cut along the central axis A; Figure 2 is a longitudinal cross-sectional view showing the writing instrument 10 in an immersed state; Figure 3 is a perspective view showing the writing instrument 10 in an extended state, with the barrel 20 cut along the central axis A; Figure 4 is a longitudinal cross-sectional view showing the writing instrument 10 in an extended state; Figure 5 is an exploded perspective view of the writing instrument 10.

[0021] The writing instrument 10 of this embodiment comprises a writing member 12, a barrel 20, and a retractable mechanism 60. The writing instrument 10 extends along a central axis A. The writing member 12 is a member that forms writing marks on a writing surface such as paper. The writing member 12 is housed within the barrel 20. As the writing member 12, for example, a member used in a ballpoint pen, fountain pen, marker, mechanical pencil, stylus pen, etc., can be used.

[0022] The barrel 20 includes a main body 22 and a tip member 24 positioned in front of the main body 22. The central axis of the barrel 20 coincides with the central axis A of the writing instrument 10. The barrel 20 houses the writing member 12, the resilient member 63, and the retractable mechanism 60. A front end opening 26 is provided at the front end of the barrel 20. In this embodiment, the tip of the writing member 12 retracts through the front end opening 26. A rear end opening 28 is provided at the rear end of the barrel 20. In this embodiment, the knock member 61, described later, protrudes rearward from the rear end opening 28.

[0023] The main body 22 is a substantially cylindrical member positioned behind the tip member 24. The main body 22 has a first groove 30 that defines the movement trajectory of the rear member 70 of the stroke increasing mechanism 65 described later, a second groove 40 that defines the movement trajectory of the intermediate member 80, and a third groove 50 that defines the movement trajectory of the front member 90. Details of the first groove 30, the second groove 40, and the third groove 50 will be described later.

[0024] The tip member 24 is a member that defines the front end opening 26. That is, the front end opening 26 is provided on the tip member 24. The tip member 24 is connected to the main body 22 by attaching the rear end of the tip member 24 to the front end of the main body 22. For example, the tip member 24 is connected to the main body 22 by screwing the female threaded portion formed on the inner circumference of the rear end of the tip member 24 into the male threaded portion formed on the outer circumference of the front end of the main body 22. In this embodiment, with the tip member 24 removed from the main body 22, the retractable mechanism 60 can be installed inside the main body 22 from the front of the main body 22. Also, the writing member 12 can be replaced by removing the tip member 24 from the main body 22.

[0025] The retraction mechanism 60 is a mechanism for alternately switching the writing instrument 10 between a protruding state in which the tip of the writing member 12 protrudes from the front end opening 26 of the barrel 20, and a retracted state in which the tip of the writing member 12 retracts from the front end opening 26, by extending and retracting the tip of the writing member 12 from the front end opening 26 of the barrel 20. The retraction mechanism 60 in this embodiment includes a knocking member 61, a spring-loaded member 63, and a stroke-increasing mechanism 65.

[0026] The knocking member 61 is a component intended to be operated directly by the user. The knocking member 61 protrudes rearward from the rear end opening 28 of the barrel 20 and is configured to be pressed forward by the user.

[0027] The resilient member 63 is a member that biases the writing member 12 toward the rear relative to the barrel 20. The resilient member 63 is, for example, a coil spring. The resilient member 63 is positioned in a compressed state between the inner step portion of the barrel 20 (tip member 24) and the front end of the front member 90, which will be described later.

[0028] In the retractable mechanism 60 of this embodiment, when the user presses the knock member 61 forward on the retracted writing instrument 10 shown in Figures 1 and 2, the writing member 12 moves forward via the stroke increasing mechanism 65, and the tip of the writing member 12 protrudes forward from the front end opening 26, causing the writing instrument 10 to be in the protruding state shown in Figures 3 and 4. Even when the forward pressure on the knock member 61 is released, the writing member 12 maintains the state in which the tip of the writing member 12 protrudes forward from the front end opening 26. When the user rotates the knock member 61 around the central axis A in the protruding state, the elastic force of the elastic member 63 causes the tip of the writing member 12 to retract into the barrel 20 from the front end opening 26, causing the writing instrument 10 to be in the retracted state shown in Figures 1 and 2. Details of the protrusion and retraction operation of the writing member 12 in this embodiment will be described later. The retractable mechanism 60 is not limited to this, and for example, a mechanism similar to the retractable mechanism having a cam groove formed on the inner surface of the shaft cylinder, a rotating cam, and a knocking body disclosed in Japanese Patent Application Publication No. 11-78361 may be used.

[0029] In this embodiment, the writing instrument 10 is configured such that when the knock member 61 is pressed forward by the user, the forward movement distance of the writing member 12 along the axial direction da is greater than the forward movement distance of the knock member 61 along the axial direction da. The stroke increasing mechanism 65 that realizes this function will be described below.

[0030] The stroke increasing mechanism 65 of this embodiment includes a first groove 30, a second groove 40, and a third groove 50 provided on the inner circumferential surface of the shaft cylinder 20, as well as a rear member 70, an intermediate member 80, and a front member 90 arranged inside the shaft cylinder 20. Figure 6 is a perspective view showing the main body portion 22 of the shaft cylinder 20 cut along the central axis A. Figures 7 and 8 show the structure of part of the stroke increasing mechanism 65. Figure 7 shows the stroke increasing mechanism 65 in the retracted state, and Figure 8 shows the stroke increasing mechanism 65 in the protruding state. Figures 7 and 8 show the shaft cylinder 20 (main body portion 22) cut open by a plane extending radially from the central axis A, and viewed from the radial outside. Figures 7 and 8 show the shapes of the first groove portion 30 and the second groove portion 40.

[0031] The first groove 30, the second groove 40, and the third groove 50 are each provided on the inner circumferential surface of the shaft cylinder 20 (main body 22). The second groove 40 is positioned in front of the first groove 30, and the third groove 50 is positioned in front of the second groove 40.

[0032] The first groove 30 is configured such that the first projection 74 of the rear member 70, described later, moves inside it. The first groove 30 has a straight section 31 extending in the axial direction da and an inclined section 33 extending forward from the front end of the straight section 31. The straight section 31 extends linearly along a direction parallel to the central axis A. The inclined section 33 communicates with the straight section 31 at its front end. The inclined section 33 extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc. In particular, the inclined section 33 extends from one side of the circumferential direction dc to the other side as it moves forward. The inclined section 33 may extend linearly or curvedly. The stroke increasing mechanism 65 may have a plurality of first grooves 30. The plurality of first grooves 30 may be provided at equal angular intervals in the circumferential direction dc. In this embodiment, the stroke increasing mechanism 65 has two first grooves 30 formed with an angular spacing of 180 degrees in the circumferential direction dc.

[0033] The inclined portion 33 has a front surface 35 and a rear surface 37 facing each other in the width direction of the inclined portion 33. The front surface 35 is a surface that defines the front side surface of the inclined portion 33 and faces rearward and to the other side in the circumferential direction dc. The rear surface 37 is a surface that defines the rear side surface of the inclined portion 33 and faces forward and to one side in the circumferential direction dc. A return stopper portion 39 is provided on the rear surface 37. The return stopper portion 39 has the function of preventing the rear member 70 from returning to the rear due to the elastic force of the elastic member 63 when the first projection 74 of the rear member 70 is located at the front end 32 of the first groove portion 30. The front end 32 of the first groove portion 30 has a width dimension that is larger than the width dimension of the inclined portion 33. The return stopper portion 39 is located at the boundary between the front end 32 and the inclined portion 33. In this embodiment, the retaining portion 39 is a stepped portion formed by the difference between the widthwise dimension of the front end portion 32 and the widthwise dimension of the inclined portion 33. In other words, the retaining portion 39 is a protruding portion located at the boundary between the front end portion 32 and the inclined portion 33, and protruding inward from the first groove portion 30.

[0034] The second groove 40 is configured such that the second projection 86 of the intermediate member 80, described later, moves inside it. The second groove 40 has a main portion 41 that extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc, and an extension portion 43 that extends rearward from the rear end of the main portion 41. In this embodiment, in Figures 7 and 8, the main portion 41 extends linearly in a direction inclined with respect to both the axial direction da and the circumferential direction dc, with an angle θ1 with respect to the axial direction da. Also in Figures 7 and 8, the extension portion 43 may extend linearly in a direction inclined with respect to both the axial direction da and the circumferential direction dc, with an angle θ2 with respect to the axial direction da. In the illustrated example, angle θ2 is smaller than angle θ1. The extension portion 43 may extend in the axial direction da. Angle θ1 may be 10 degrees or more and 60 degrees or less. Preferably, angle θ1 may be 15 degrees or more and 45 degrees or less. Also, angle θ2 may be 0 degrees or more and 30 degrees or less. Preferably, the angle θ2 may be between 1 degree and 15 degrees. The main portion 41 and the extension portion 43 may extend in a curved shape as shown in Figures 7 and 8. The stroke increasing mechanism 65 may have a plurality of second grooves 40. The plurality of second grooves 40 may be provided at equal angular intervals in the circumferential direction dc. In this embodiment, the stroke increasing mechanism 65 has two second grooves 40 formed at an angular interval of 180 degrees in the circumferential direction dc.

[0035] The second groove 40 has a front surface 45 and a rear surface 47 facing each other in the width direction of the second groove 40. The front surface 45 is a surface that defines the front side surface of the second groove 40 and faces rearward and to the other side in the circumferential direction dc. The rear surface 47 is a surface that defines the rear side surface of the second groove 40 and faces forward and to one side in the circumferential direction dc.

[0036] The third groove 50 is configured such that the third projection 94 of the front member 90, described later, moves inside it. The third groove 50 extends linearly in the axial direction da. However, it is not limited to this, and the third groove 50 may have portions that extend in a direction inclined with respect to both the axial direction da and the circumferential direction dc. The stroke increasing mechanism 65 may have a plurality of third grooves 50. The plurality of third grooves 50 may be provided at equal angular intervals in the circumferential direction dc. In this embodiment, the stroke increasing mechanism 65 has two third grooves 50 formed at an angular interval of 180 degrees in the circumferential direction dc.

[0037] Next, the rear member 70, the intermediate member 80, and the front member 90 will be described.

[0038] The rear member 70 is a member that moves forward when the knock member 61 is pressed forward by the user, receiving the pressing force from the knock member 61. In this embodiment, the rear member 70 is a hollow member having a substantially cylindrical shape. This reduces the weight of the rear member 70, making it possible to lighten the stroke increasing mechanism 65. However, it is not limited to this, and the rear member 70 may be a solid member. In this embodiment, the knock member 61 and the rear member 70 are formed as an integrated member. Therefore, the knock member 61 and the rear member 70 move together. However, it is not limited to this, and the knock member 61 and the rear member 70 may be configured as separate members. The rear member 70 has a first cam surface 72 facing forward. The first cam surface 72 is provided at the front end of the rear member 70. In the immersed state of the writing instrument 10 (see Figures 1 and 2), the first cam surface 72 extends in a direction inclined with respect to the axial direction da and the first direction d1, such that it moves from one side of the first direction d1 perpendicular to the central axis A to the other side as it moves from rear to front. In this embodiment, the first cam surface 72 is a plane, but is not limited to this, and the first cam surface 72 may be a curved surface.

[0039] A first projection 74 is provided on the outer circumferential surface of the rear member 70. The first projection 74 is formed to protrude radially from the outer circumferential surface of the rear member 70. The first projection 74 has a cylindrical shape with a circular outline when viewed from the radial direction. The first projection 74 is located within the first groove 30 of the shaft cylinder 20 (main body 22) and is movable within the first groove 30. As a result, the rear member 70 is configured to be movable along the first groove 30. As described above, the first groove 30 has a straight section 31 and an inclined section 33. When the first projection 74 is located within the straight section 31 of the first groove 30, the rear member 70 is movable axially da but cannot rotate around the central axis A. Also, when the first projection 74 is located within the inclined section 33 of the first groove 30, the rear member 70 is movable axially da along the inclined section 33 and can rotate around the central axis A. The rear member 70 may have a plurality of first protrusions 74. In particular, the rear member 70 may have the same number of first protrusions 74 as the number of first grooves 30. The plurality of first protrusions 74 may be arranged at equal angular intervals in the circumferential direction dc. In this embodiment, the rear member 70 has two first protrusions 74 formed at an angular interval of 180 degrees in the circumferential direction dc.

[0040] The intermediate member 80 is a member positioned in front of the rear member 70. In this embodiment, the intermediate member 80 is a hollow member having a substantially cylindrical shape. This reduces the weight of the intermediate member 80, making it possible to lighten the stroke increasing mechanism 65. However, it is not limited to this, and the intermediate member 80 may be a solid member. The intermediate member 80 has a second cam surface 82 facing rear and a third cam surface 84 facing forward. The second cam surface 82 is provided at the rear end of the intermediate member 80, and the third cam surface 84 is provided at the front end of the intermediate member 80. In the immersed state of the writing instrument 10 (see Figures 1 and 2), the second cam surface 82 extends in an axial direction da and a direction inclined with respect to the first direction d1, so as it moves from rear to front, it moves from one side of the first direction d1 perpendicular to the central axis A to the other side. Furthermore, in the immersed state of the writing instrument 10, the third cam surface 84 extends in a direction inclined with respect to the axial direction da and the first direction d1, such that it moves from one side of the first direction d1 perpendicular to the central axis A to the other side as it moves from the rear to the front. In this embodiment, the second cam surface 82 and the third cam surface 84 extend parallel to each other. In this embodiment, the second cam surface 82 and the third cam surface 84 are planar, but are not limited to this, and the second cam surface 82 and the third cam surface 84 may be curved surfaces. In the immersed state of the writing instrument 10, the second cam surface 82 is in surface contact with the first cam surface 72 of the rear member 70.

[0041] A second projection 86 is provided on the outer circumferential surface of the intermediate member 80. The second projection 86 is formed to protrude radially from the outer circumferential surface of the intermediate member 80. The second projection 86 has a cylindrical shape with a circular contour when viewed from the radial direction. The second projection 86 is located within the second groove 40 of the shaft cylinder 20 (main body portion 22) and is movable within the second groove 40. As a result, the intermediate member 80 is configured to be movable along the second groove 40. As described above, the second groove 40 has a main portion 41 and an extension portion 43. When the second projection 86 is located within the main portion 41 of the second groove 40, the intermediate member 80 is movable axially da along the main portion 41 and is rotatable about the central axis A. When the extension 43 extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc, and the second projection 86 is located within the extension 43 of the second groove 40, the intermediate member 80 is movable along the extension 43 in the axial direction da and rotatable around the central axis A. Also, when the extension 43 extends along the axial direction da, and the second projection 86 is located within the extension 43 of the second groove 40, the intermediate member 80 is movable along the extension 43 in the axial direction da but not rotatable around the central axis A. The intermediate member 80 may have a plurality of second projections 86. In particular, the intermediate member 80 may have the same number of second projections 86 as the number of second grooves 40. The plurality of second projections 86 may be arranged at equal angular intervals in the circumferential direction dc. In this embodiment, the intermediate member 80 has two second projections 86 formed at an angular interval of 180 degrees in the circumferential direction dc.

[0042] The front member 90 is a member positioned in front of the intermediate member 80. The front member 90 has a fourth cam surface 92 facing backward. The fourth cam surface 92 is provided at the rear end of the front member 90. In the immersed state of the writing instrument 10 (see Figures 1 and 2), the fourth cam surface 92 extends in a direction inclined with respect to the axial direction da and the first direction d1, such that it moves from one side of the first direction d1 perpendicular to the central axis A to the other side as it moves from rear to front. In this embodiment, in the immersed state, the first cam surface 72, the second cam surface 82, the third cam surface 84 and the fourth cam surface 92 extend parallel to each other. In this embodiment, the fourth cam surface 92 is a plane, but is not limited to this, and the fourth cam surface 92 may be a curved surface. In the immersed state of the writing instrument 10, the fourth cam surface 92 is in surface contact with the third cam surface 84 of the intermediate member 80.

[0043] A third projection 94 is provided on the outer circumferential surface of the front member 90. The third projection 94 is formed to protrude radially from the outer circumferential surface of the front member 90. In this embodiment, the third projection 94 has a prismatic shape with a rectangular contour when viewed from the radial direction. However, it is not limited to this, and the third projection 94 may have a cylindrical shape with a circular contour when viewed from the radial direction. The third projection 94 is located within the third groove 50 of the shaft cylinder 20 (main body 22) and is movable within the third groove 50. As a result, the front member 90 is configured to be movable along the third groove 50. As described above, in this embodiment, the third groove 50 extends linearly in the axial direction da. In this case, the front member 90 is movable in the axial direction da along the third groove 50 and cannot rotate around the central axis A. The front member 90 may have a plurality of third projections 94. In particular, the front member 90 may have the same number of third protrusions 94 as the number of third grooves 50. The multiple third protrusions 94 may be arranged at equal angular intervals in the circumferential direction dc. In this embodiment, the front member 90 has two third protrusions 94 formed at an angular interval of 180 degrees in the circumferential direction dc.

[0044] A writing member 12 is attached to the front end of the front member 90. This allows the writing member 12 to move axially da together with the front member 90. In this embodiment, the writing member 12 is attached to the front member 90 by press-fitting its rear end into a recess provided at the front end of the front member 90.

[0045] Next, we will explain the mechanism for extending and retracting the writing instrument 10.

[0046] The resilient member 63 is positioned in a compressed state between the inner step portion of the barrel 20 (tip member 24) and the front end of the front member 90. Therefore, the front member 90 is biased backward by the resilient force of the resilient member 63. As a result, the intermediate member 80, the rear member 70, and the knock member 61 are also biased backward. In the retracted state (Figures 1, 2, and 7), the rear end of the rear member 70 abuts against the inner step portion located on the inner circumferential surface of the rear end of the barrel 20 (tip member 24), and the knock member 61, rear member 70, intermediate member 80, front member 90, and writing member 12 are located at the rearmost end of their range of motion in the axial direction da.

[0047] In the immersed state, as shown in Figure 7, the first projection 74 of the rear member 70 is located within the straight portion 31 of the first groove 30, and the second projection 86 of the intermediate member 80 is located within the extension 43 of the second groove 40. Also, the third projection 94 of the front member 90 is located within the third groove 50. Furthermore, in the immersed state, as shown in Figures 1 and 2, the second cam surface 82 of the intermediate member 80 and the first cam surface 72 of the rear member 70 are in surface contact with each other. Also, the fourth cam surface 92 of the front member 90 and the third cam surface 84 of the intermediate member 80 are in surface contact with each other. In the immersed state, the first cam surface 72, the second cam surface 82, the third cam surface 84, and the fourth cam surface 92 all extend in the axial direction da and in a direction inclined with respect to the first direction d1, so as you move from rear to front, you move from one side of the first direction d1 perpendicular to the central axis A to the other side.

[0048] As shown in Figures 1, 2, and 7, in the immersed state, the first protrusion 74 and the second protrusion 86 are separated by a distance L1 along the axial direction da. Also, in the immersed state, the second protrusion 86 and the third protrusion 94 are separated by a distance L2 along the axial direction da.

[0049] In the immersion state, when the user presses the knock member 61 forward, the knock member 61 moves forward against the elastic force of the resilient member 63. As the knock member 61 moves forward, the rear member 70 also moves forward. While the first projection 74 of the rear member 70 is located within the straight section 31 of the first groove 30, the rear member 70 moves axially da and does not rotate around the central axis A.

[0050] As the rear member 70 moves forward, the intermediate member 80 moves forward along the second groove 40 due to the pressing force from the rear member 70. In this embodiment, the second groove 40 has a main portion 41 and an extension portion 43, and the angle θ2 between the direction in which the extension portion 43 extends and the axial direction da is smaller than the angle θ1 between the direction in which the main portion 41 extends and the axial direction da. Therefore, while the second projection 86 of the intermediate member 80 is located within the extension portion 43, the intermediate member 80 rotates around the central axis A with an angle θ2 smaller than the angle θ1 with respect to the axial direction da. Consequently, the component force directed towards the rear of the resistance force acting from the front surface 45 of the second groove 40 to the second projection 86 due to the elastic force of the elastic member 63 is reduced. Therefore, the intermediate member 80 can be moved smoothly toward the front.

[0051] As the intermediate member 80 moves further forward, the second projection 86 is positioned within the main portion 41 of the second groove 40. While the second projection 86 is positioned within the main portion 41, the intermediate member 80 rotates around the central axis A with an angle θ1 greater than the angle θ2 with respect to the axial direction da. In particular, as the intermediate member 80 moves forward, it rotates from one side to the other in the circumferential direction dc. At this time, the angle of rotation around the central axis A with respect to the distance of movement in the axial direction da becomes larger compared to when the second projection 86 is positioned within the extension 43. As a result, the intermediate member 80 rotates significantly around the central axis A. As described above, while the first projection 74 of the rear member 70 is positioned within the straight portion 31 of the first groove 30, the rear member 70 moves in the axial direction da and does not rotate around the central axis A. In this case, as the intermediate member 80 rotates around its central axis A, the direction in which the first cam surface 72 of the rear member 70 extends and the direction in which the second cam surface 82 of the intermediate member 80 extend become misaligned. As a result, the first cam surface 72 and the second cam surface 82 no longer make surface contact with each other, and parts of the first cam surface 72 and parts of the second cam surface 82 come into contact with each other. Consequently, the intermediate member 80 moves forward by a distance greater than the axial movement distance da of the rear member 70. That is, as the rear member 70 moves forward, the intermediate member 80 rotates in the circumferential direction dc relative to the shaft cylinder 20 and moves forward by a distance greater than the axial movement distance da of the rear member 70.

[0052] Furthermore, the front member 90 is movable in the axial direction da, but does not rotate around the central axis A. In this case, as the intermediate member 80 rotates around the central axis A, the direction in which the third cam surface 84 of the intermediate member 80 extends and the direction in which the fourth cam surface 92 of the front member 90 extends become misaligned. As a result, the third cam surface 84 and the fourth cam surface 92 no longer make surface contact with each other, and parts of the third cam surface 84 and parts of the fourth cam surface 92 come into contact with each other. Consequently, the front member 90 moves forward by a distance greater than the axial movement distance da of the intermediate member 80. That is, when the intermediate member 80 moves forward, the front member 90 moves forward by a distance greater than the axial movement distance da of the intermediate member 80.

[0053] Therefore, when the knocking member 61 is pressed forward by the user, the forward movement distance of the writing member 12, which moves together with the front member 90, along the axial direction da is greater than the forward movement distance of the knocking member 61 along the axial direction da.

[0054] As the rear member 70 moves further forward, the first projection 74 of the rear member 70 comes into position within the inclined portion 33 of the first groove 30. At this time, the rear member 70 moves along the first groove 30 in the axial direction da and rotates around the central axis A. In particular, as the rear member 70 moves forward, it rotates from one side to the other in the circumferential direction dc. That is, as the rear member 70 moves forward, it rotates in the same direction as the rotation direction of the intermediate member 80. This reduces the pressing force acting from the rear member 70 to the intermediate member 80. Therefore, the load on the rear member 70 and the intermediate member 80 is reduced. Thus, deformation or damage to the first cam surface 72 of the rear member 70 and the second cam surface 82 of the intermediate member 80 can be suppressed.

[0055] Subsequently, the first protrusion 74 is positioned within the front end portion 32 of the first groove portion 30. When the user releases the pressure on the knock member 61 in this state, the elastic force of the resilient member 63 presses the first protrusion 74 against the rear surface of the front end portion 32. Since a return stopper portion 39 is provided on the rear surface 37 of the inclined portion 33, the first protrusion 74 is prevented from returning from the front end portion 32 to the inclined portion 33. As a result, even when the user releases the forward pressure on the knock member 61, the writing member 12 does not retract from the front end opening 26 of the barrel 20, and the writing instrument 10 is maintained in the protruding state shown in Figures 3, 4, and 8.

[0056] In the protruding state, as shown in Figures 3, 4, and 8, the first protrusion 74 and the second protrusion 86 are separated by a distance L3 along the axial direction da. Also in the protruding state, the second protrusion 86 and the third protrusion 94 are separated by a distance L4 along the axial direction da. The distance L3 between the first protrusion 74 and the second protrusion 86 in the protruding state is greater than the distance L1 between the first protrusion 74 and the second protrusion 86 in the immersed state. Also, the distance L4 between the second protrusion 86 and the third protrusion 94 in the protruding state is greater than the distance L2 between the second protrusion 86 and the third protrusion 94 in the immersed state.

[0057] In the protruding state, when the user grasps the knock member 61 and rotates it around the central axis A, particularly when the knock member 61 is rotated from one side to the other in the circumferential direction dc, the first protrusion 74 of the rear member 70 moves beyond the return stopper 39 of the first groove 30 and into the inclined portion 33. When the user releases their grip on the knock member 61 in this state, the elastic force of the elastic member 63 causes the rear member 70, the intermediate member 80, and the front member 90 to move backward. At this time, the first protrusion 74 of the rear member 70 moves backward within the first groove 30, the second protrusion 86 of the intermediate member 80 moves backward within the second groove 40, and the third protrusion 94 of the front member 90 moves backward within the third groove 50. Subsequently, when the rear end of the rear member 70 contacts the inner step located on the inner circumferential surface of the rear end of the barrel 20 (tip member 24), the rear member 70, intermediate member 80, and front member 90 stop and return to the retracted state shown in Figures 1, 2, and 7. At this time, the tip of the writing member 12 retracts through the front end opening 26 of the barrel 20.

[0058] The writing instrument 10 of this embodiment comprises a barrel 20 having a central axis A and a front end opening 26, a writing member 12 disposed inside the barrel 20, and a retractable mechanism 60 that extends and retracts the tip of the writing member 12 from the front end opening 26. The retractable mechanism 60 includes a knock member 61 that can be pressed forward by the user, and a stroke increasing mechanism 65 that moves the writing member 12 forward by a distance greater than the axial travel distance da of the knock member 61 when the knock member 61 is pressed forward. The stroke increasing mechanism 65 includes a rear member 70 having a first cam surface 72 facing forward, and an intermediate member 80 disposed in front of the rear member 70 and having a second cam surface 82 facing backward and a third cam surface 84 facing forward. The writing instrument 10 has a front member 90 positioned in front of the intermediate member 80 and having a fourth cam surface 92 facing backward. When the writing instrument 10 is immersed, the first cam surface 72, second cam surface 82, third cam surface 84, and fourth cam surface 92 all extend in an axial direction da and a direction inclined with respect to the first direction d1, so that as you move from rear to front, you move from one side of the first direction d1 perpendicular to the central axis A to the other. When the rear member 70 moves forward, the intermediate member 80 moves forward by a distance greater than the distance the rear member 70 moves in the axial direction da, while rotating in the circumferential direction dc relative to the barrel 20, and the front member 90 moves forward by a distance greater than the distance the intermediate member 80 moves in the axial direction da.

[0059] With this writing instrument 10, which has a rear member 70, an intermediate member 80, and a front member 90, the intermediate member 80 moves forward by a distance greater than the axial movement distance da of the rear member 70, and the front member 90 moves forward by an even greater distance than the axial movement distance da of the intermediate member 80, so that the movement distance of the writing member 12 can be made sufficiently larger than the movement distance of the knock member 61 compared to conventional writing instruments. Furthermore, in the immersed state, the first cam surface 72, the second cam surface 82, the third cam surface 84, and the fourth cam surface 92 all extend in a direction inclined with respect to the axial direction da and the first direction d1, so that they move from one side of the first direction d1 to the other side as they move from rear to front, so that the stroke increasing mechanism 65 in the immersed state can be made compact.Therefore, even while miniaturizing the stroke increasing mechanism 65, the movement distance of the writing member 12 can be made sufficiently larger than the movement distance of the knock member 61.

[0060] In the writing instrument 10 of this embodiment, the stroke increasing mechanism 65 has a first groove 30 provided on the inner circumferential surface of the barrel 20, the first groove 30 has a straight portion 31 extending in the axial direction da, and the rear member 70 has a first protrusion 74 located within the first groove 30.

[0061] In the writing instrument 10 of this embodiment, the stroke increasing mechanism 65 has a second groove 40 provided on the inner circumferential surface of the barrel 20, the second groove 40 has a main portion 41 that extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc, and the intermediate member 80 has a second projection 86 located within the second groove 40.

[0062] In the writing instrument 10 of this embodiment, the stroke increasing mechanism 65 has a third groove 50 provided on the inner circumferential surface of the barrel 20, the third groove 50 extends in the axial direction da, and the front member 90 has a third projection 94 located within the third groove 50.

[0063] With this writing instrument 10, the rear member 70, the intermediate member 80, and the front member 90 can move stably and smoothly along the first groove 30, the second groove 40, and the third groove 50, respectively.

[0064] In the writing instrument 10 of this embodiment, the first groove portion 30 has an inclined portion 33 that extends forward from the front end of the straight portion 31, and the inclined portion 33 extends in a direction inclined with respect to both the axial direction da and the circumferential direction dc.

[0065] With this writing instrument 10, when the first projection 74 of the rear member 70 is located within the inclined portion 33, the rear member 70 moves forward and rotates in the same direction as the rotation direction of the intermediate member 80. This reduces the pressing force acting from the rear member 70 to the intermediate member 80. Therefore, the load on the rear member 70 and the intermediate member 80 is reduced. Thus, deformation or damage to the first cam surface 72 of the rear member 70 and the second cam surface 82 of the intermediate member 80 can be suppressed.

[0066] In the writing instrument 10 of this embodiment, a return stopper 39 is provided on the rear surface 37 of the inclined portion 33.

[0067] With this writing instrument 10, when the user releases pressure on the knocking member 61 while the first protrusion 74 is positioned within the front end portion 32 of the first groove portion 30, the return stopper portion 39 prevents the first protrusion 74 from returning from the front end portion 32 to the inclined portion 33. As a result, even when the user releases pressure on the knocking member 61, the writing member 12 does not retract from the front end opening 26 of the barrel 20, and the writing instrument 10 remains in a protruding state. Therefore, a mechanism for maintaining the writing instrument 10 in a protruding state can be realized with a simple configuration.

[0068] In the writing instrument 10 of this embodiment, the second groove portion 40 has an extension portion 43 that extends rearward from the rear end of the main portion 41, and the angle θ2 between the direction in which the extension portion 43 extends and the axial direction da is smaller than the angle θ1 between the direction in which the main portion 41 extends and the axial direction da.

[0069] With this writing instrument 10, when transitioning from a retracted state to a protruding state, the component of the resistance force acting from the front surface 45 of the second groove 40 to the second protrusion 86 due to the elastic force of the resilient member 63, which is directed backward, becomes smaller. Therefore, the intermediate member 80 can be moved smoothly forward. [Explanation of Symbols]

[0070] 10 Writing instruments 12 Writing components 20 shaft cylinder 22 Main body 24 Tip member 26 Front end opening 28 Rear end opening 30 First groove 31 Straight section 32 Front end 33 Slope 35 Front 37 Rear 39 Retraction mechanism 40 Second trench section 41 Main part 43 Extension 45 Front 47 Rear 50 Third groove 60 Appearance mechanism 61 Knock Member 63 Resilient components 65 Stroke Increase Mechanism 70 Rear member 72 First cam surface 74 1st protrusion 80 Intermediate member 82 Second cam surface 84 Third cam surface 86 Second protrusion 90 Front member 92 Fourth cam surface 94 Third protrusion A Center axis da axis direction dc circumferential direction d1 1st direction

Claims

1. A writing instrument comprising a barrel having a central axis and a front end opening, a writing member disposed within the barrel, and a retractable mechanism for extending and retracting the tip of the writing member from the front end opening, The aforementioned appearance / disappearance mechanism is, A knocking member that can be pressed forward by the user, The device includes a stroke increasing mechanism that, when the knocking member is pressed forward, moves the writing member forward by a distance greater than the axial travel distance of the knocking member. The stroke increasing mechanism is, A rear member having a first cam surface facing forward, An intermediate member positioned in front of the aforementioned rear member, having a second cam surface facing rear and a third cam surface facing forward, A front member positioned in front of the intermediate member and having a fourth cam surface facing rear, The shaft has a first groove provided on the inner circumferential surface, The first groove portion has a straight portion extending in the axial direction, The rear member has a first projection located within the first groove, In the immersed state of the writing instrument, the first cam surface, the second cam surface, the third cam surface, and the fourth cam surface all extend in a direction inclined with respect to the axial direction and the first direction, such that they move from one side of the first direction perpendicular to the central axis to the other side as they move from rear to front. A writing instrument in which, when the rear member moves forward, the intermediate member rotates circumferentially with respect to the barrel and moves forward by a distance greater than the axial movement distance of the rear member, and the front member moves forward by a distance greater than the axial movement distance of the intermediate member.

2. The first groove portion has an inclined portion extending forward from the front end of the straight portion, The writing instrument according to claim 1, wherein the inclined portion extends in a direction inclined with respect to both the axial and circumferential directions.

3. The writing instrument according to claim 2, wherein a stopper is provided on the rear surface of the inclined portion.

4. A writing instrument comprising: a barrel having a central axis and a front end opening; a writing member disposed inside the barrel; and a retraction mechanism for extending and retracting the tip of the writing member from the front end opening, The aforementioned appearance / disappearance mechanism is, A knocking member that can be pressed forward by the user, The device includes a stroke increasing mechanism that, when the knocking member is pressed forward, moves the writing member forward by a distance greater than the axial travel distance of the knocking member. The stroke increasing mechanism is, A rear member having a first cam surface facing forward, An intermediate member positioned in front of the aforementioned rear member, having a second cam surface facing rear and a third cam surface facing forward, A front member positioned in front of the intermediate member and having a fourth cam surface facing rear, The shaft has a second groove provided on the inner circumferential surface, The second groove has a main portion that extends in a direction inclined with respect to both the axial and circumferential directions, The intermediate member has a second projection located within the second groove, In the immersed state of the writing instrument, the first cam surface, the second cam surface, the third cam surface, and the fourth cam surface all extend in a direction inclined with respect to the axial direction and the first direction, such that they move from one side of the first direction perpendicular to the central axis to the other side as they move from rear to front. A writing instrument in which, when the rear member moves forward, the intermediate member rotates circumferentially with respect to the barrel and moves forward by a distance greater than the axial movement distance of the rear member, and the front member moves forward by a distance greater than the axial movement distance of the intermediate member.

5. The second groove portion has an extension portion that extends rearward from the rear end of the main portion, The writing instrument according to claim 4, wherein the angle between the direction in which the extension extends and the axial direction is smaller than the angle between the direction in which the main part extends and the axial direction.

6. A writing instrument comprising: a barrel having a central axis and a front end opening; a writing member disposed inside the barrel; and a retraction mechanism for extending and retracting the tip of the writing member from the front end opening, The aforementioned appearance / disappearance mechanism is, A knocking member that can be pressed forward by the user, The device includes a stroke increasing mechanism that, when the knocking member is pressed forward, moves the writing member forward by a distance greater than the axial travel distance of the knocking member. The stroke increasing mechanism is, A rear member having a first cam surface facing forward, An intermediate member positioned in front of the aforementioned rear member, having a second cam surface facing rear and a third cam surface facing forward, A front member positioned in front of the intermediate member and having a fourth cam surface facing rear, The shaft cylinder has a third groove provided on its inner circumferential surface, The third groove extends in the axial direction, The front member has a third projection located within the third groove, In the immersed state of the writing instrument, the first cam surface, the second cam surface, the third cam surface, and the fourth cam surface all extend in a direction inclined with respect to the axial direction and the first direction, such that they move from one side of the first direction perpendicular to the central axis to the other side as they move from rear to front. A writing instrument in which, when the rear member moves forward, the intermediate member rotates circumferentially with respect to the barrel and moves forward by a distance greater than the axial movement distance of the rear member, and the front member moves forward by a distance greater than the axial movement distance of the intermediate member.

Images