Mechanical pencil

Abstract

An automatic pencil (10) has: a shaft cylinder (20) containing a main shaft (22); a lead feed mechanism (30) feeding a writing lead (80); a weight body (50) configured to be able to move forward and backward relative to the main shaft; an operation body (61) able to rotate relative to the main shaft around a central axis (A); a moving member (64) configured to be able to move forward and backward relative to the operation body and to move between a limit position and a non-limit position that is rearward of the limit position; a limit member (68) limiting forward and backward movement of the weight body when the moving member is in the limit position; at least two cam slopes (63a) provided in one of the operation body and the moving member; and at least two abutting portions (64b) provided in the other of the operation body and the moving member, the cam slopes and the abutting portions coming into contact with each other and the abutting portions moving along the cam slopes when the operation body rotates around the central axis.

Description

Technical Field

[0001] This invention relates to mechanical pencils. Background Technology

[0002] Previously, mechanical pencils were known to have a weight inside a barrel that could move back and forth relative to the barrel. In this mechanical pencil, the weight moves back and forth inside the barrel when the user swings the barrel back and forth. At this time, the weight that has moved forward collides with a part of the lead delivery mechanism, thereby activating the lead delivery mechanism to deliver the writing lead. Such mechanical pencils have the advantage of being able to deliver the writing lead without changing the barrel. Such a vibrating mechanical pencil is disclosed in JPH9-1980.

[0003] In traditional mechanical pencils with a snap-out mechanism, the weight of the pencil may accidentally shift back and forth due to vibration or tilting when it is placed in a bag or similar container, causing the writing lead to be ejected. In such cases, the writing lead may break, or the inner surface of the bag or other items stored inside the bag may be soiled by the ejected or broken writing lead. Summary of the Invention

[0004] The present invention was made with this in mind, and its purpose is to suppress the writing lead from being ejected due to accidental back-and-forth movement of the weight in a mechanical pencil having a weight.

[0005] In one embodiment of the present invention, [1] a mechanical pencil includes: a cylinder containing a main shaft; a lead feeding mechanism for feeding writing leads; a weight body configured to move back and forth relative to the main shaft; an operating body rotatable about a central axis relative to the main shaft; a moving member configured to move back and forth relative to the operating body and to move between a restricted position and a non-restricted position further rearward than the restricted position; a limiting member restricting the back and forth movement of the weight body when the moving member is in the restricted position; at least two cam ramps disposed on one of the operating body and the moving member; and at least two abutments disposed on the other of the operating body and the moving member, wherein when the operating body rotates about the central axis, the cam ramps contact each other and the abutments move along the cam ramps.

[0006] In another embodiment of the invention, [2] according to the mechanical pencil of [1], wherein the operating body includes at least a portion of a rear shaft disposed outside the rear portion of the main shaft.

[0007] In another embodiment of the invention, [3] according to the mechanical pencil of [1] or [2], wherein the lead delivery mechanism has: a chuck that holds the writing lead; and a chuck force spring that applies a force to the chuck backward, wherein when the moving member is in the restricted position, the pressing force of the restricted member against the weight body is less than the elastic force of the chuck force spring.

[0008] In another embodiment of the invention, [4] a mechanical pencil according to any one of [1] to [3], wherein when the moving part is located at the restricted position and the weight body is at the foremost position, a gap is formed between the weight body and the restricted part.

[0009] In another embodiment of the invention, [5] the mechanical pencil according to any one of [1] to [4], wherein the limiting member is an elastic member.

[0010] In another embodiment of the invention, [6] according to the mechanical pencil of [5], wherein the elastic component is a helical spring.

[0011] In another embodiment of the invention, [7] the mechanical pencil according to any one of [1] to [6], wherein the mechanical pencil has a moving member force spring that applies force to the moving member backward.

[0012] In another embodiment of the invention, [8] the mechanical pencil according to any one of [1] to [7], wherein the spindle has a groove provided on the inner circumferential surface and extending axially, and the moving member has a protrusion capable of moving within the groove.

[0013] According to the present invention, in a mechanical pencil having a weight body, it is possible to prevent the writing lead from being ejected due to accidental back-and-forth movement of the weight body. Attached Figure Description

[0014] Figure 1 This is a figure illustrating one embodiment of the present invention, a longitudinal sectional view showing an example of a mechanical pencil in a non-limiting state.

[0015] Figure 2 It is shown in magnification Figure 1 A longitudinal sectional view of the movement restriction mechanism of a mechanical pencil.

[0016] Figure 3 This is an enlarged longitudinal sectional view showing the movement restriction mechanism in the restricted state.

[0017] Figure 4 Is with Figure 3 The cross section view corresponding to line IV-IV.

[0018] Figure 5 It is an exploded 3D view showing a portion of a mechanical pencil.

[0019] Figure 6 This is a perspective view showing the mechanical pencil with its main shaft cut along its central axis.

[0020] Figure 7 This is a perspective view showing the rotating part of a mechanical pencil cut along its central axis.

[0021] Figure 8 This is a diagram showing a portion of a movement restriction mechanism in an unrestricted state.

[0022] Figure 9 This is a diagram showing a portion of a movement restriction mechanism in a restricted state. Detailed Implementation

[0023] Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings accompanying this specification, for ease of illustration and understanding, the scale and aspect ratios relative to the actual scale and aspect ratios have been appropriately altered and exaggerated.

[0024] Furthermore, the terms used in this specification to define shapes, geometric conditions, and their degrees, such as "parallel," "perpendicular," "same," etc., as well as the values ​​of length and angle, are not limited to a strict meaning, but are interpreted to include a range of degrees to which the same function can be expected.

[0025] In this specification, the direction in which the central axis A of the writing instrument extends (the length direction, the vertical direction in a longitudinal sectional view) is defined as the axial direction da, the direction perpendicular to the central axis A is defined as the radial direction dr, and the direction along the circumference of the central axis A is defined as the circumferential direction dc. Furthermore, along the axial direction da, the side closer to the writing surface, such as the paper, is defined as the front, and the side farther from the writing surface is defined as the rear. Additionally, along the radial direction dr, the direction toward the central axis A is defined as the inner side or inner direction, and the direction farther from the central axis A is defined as the outer side or outer direction.

[0026] Figure 1 This diagram illustrates one embodiment of the present invention and is a longitudinal sectional view showing an example of a mechanical pencil 10 in a non-limiting state. The mechanical pencil 10 of this embodiment includes a cylinder 20, a lead feeding mechanism 30, a weight body 50, and a movement limiting mechanism 60. Furthermore, the mechanical pencil 10 has a central axis A extending along its length.

[0027] The cylinder 20 includes a main shaft 22, a rear shaft 24, a front end component 26, and a grip component 28. The central axis of the cylinder 20 coincides with the central axis A of the mechanical pencil 10. A front opening 20a is provided at the front end of the cylinder 20, through which the writing lead 80 can pass. In this embodiment, the front opening 20a is an opening formed at the front end of the front end component 26. The lead delivery mechanism 30 is a mechanism that delivers the writing lead 80 forward from the front opening 20a by the user's operation.

[0028] The main spindle 22 is a component with a generally cylindrical shape. The rear spindle 24 is a component with a generally cylindrical shape disposed behind the main spindle 22. The rear spindle 24 is mounted to the main spindle 22 in a manner that allows it to rotate about the central axis A but cannot move back and forth. In particular, in this embodiment, the rear spindle 24 is mounted to the main spindle 22 via the rotating member 62 described later. In this embodiment, the rear spindle 24 and the rotating member 62 together constitute the operating body 61 described later. The front end member 26 is a component that forms the front end portion of the mechanical pencil 10. The front end member 26 has a generally conical shape, and its outer diameter decreases as it faces forward. The rear end of the front end member 26 is mounted to the front end of the main spindle 22, thereby connecting the front end member 26 to the main spindle 22. As an example, the internal thread portion formed on the inner circumferential surface of the front end member 26 engages with the external thread portion formed on the outer circumferential surface of the front end of the main spindle 22, thereby connecting the front end member 26 to the main spindle 22. The grip component 28 is formed of an elastic component such as rubber or an elastomer, intended for the user to grip with their fingers when writing with the mechanical pencil 10.

[0029] Furthermore, in this specification, "cannot move back and forth" does not mean it is limited to not moving back and forth at all. That is, "cannot move back and forth" or "cannot move in the axial direction da" includes the concept of having clearance that limits further movement. Similarly, "cannot rotate" or "cannot move in the circumferential direction dc" includes the concept of having clearance that limits further rotation or movement.

[0030] The core delivery mechanism 30 is a mechanism that delivers the writing core 80 forward from the front opening 20a of the shaft cylinder 20 by the user's operation. The core delivery mechanism 30 of this embodiment includes a pressing body 40, a core tube 31, a clamp 32, a connector 33, a clamp force spring 35, a bearing member 36, a fastener 37, and a core retainer 38.

[0031] The actuating element 40 is a component that is pressed forward by the user when the writing refill 80 is dispensed. The actuating element 40 is configured to move back and forth relative to the operating body 61 (rotating component 62). Furthermore, the actuating element 40 may or may not rotate relative to the operating body 61 about its central axis A. Figure 1In the example shown, the actuating body 40 includes a pressing member 42, an erasing member 44, and a cap 46. The pressing member 42 has the function of pressing the core tube 31 forward when the actuating body 40 is pressed forward. In the illustrated example, the pressing member 42 is a member having a generally cylindrical shape. The erasing member 44 is a member used to erase pen marks by rubbing them off. The erasing member 44 is, for example, an eraser. The cap 46 is a member installed at the rear end of the pressing member 42 in a manner that covers the erasing member 44, and is intended to be pressed by contact with the user's fingers or the like when the user presses the actuating body 40 forward.

[0032] A press-body force spring 48 is disposed between the operating body 61 (rotating component 62) and the press body 40. The press-body force spring 48 is disposed between the operating body 61 and the press body 40 in a compressed state. The press-body force spring 48 is, for example, a coil spring. The spring force of the clamping spring 35, which applies force to the clamp 32 backward, can also be set to be relatively small so that the writing lead 80 can be properly delivered by the impact load of the weight body 50. However, in this case, when the press body 40 comes into contact with the user or other objects, even with a small force, the clamp 32 moves forward, and the writing lead 80 may be accidentally delivered. The mechanical pencil 10 of this embodiment, by having a press-body force spring 48, can increase the pressing force of the press body 40 required to deliver the writing lead 80 without increasing the spring force of the clamping spring 35. Therefore, when the press body 40 comes into contact with the user or other objects, the accidental delivery of the writing lead 80 can be prevented.

[0033] The pressing member 42 has: a protrusion 42a that protrudes outward from the outer periphery of the front portion toward the radially dr direction; an outer bezel 42b located behind the protrusion 42a and formed protruding outward from the outer periphery toward the radially dr direction; and an inner bezel 42c that protrudes inward from the inner periphery toward the radially dr direction. The protrusion 42a is engaged with the inner bezel 62a of the rotating member 62 (described later), restricting the rearward movement of the pressing body 40 relative to the rotating member 62. The outer bezel 42b is the portion that receives the elastic force of the pressing body force spring 48. When the pressing body 40 is pressed forward, the inner bezel 42c abuts against the rear end of the core tube 31, pressing the core tube 31 forward.

[0034] The core tube 31 is a component that internally stores the writing core 80. Furthermore, in this embodiment, the core tube 31 also functions to transmit pressure from the pusher 40 to the connector 33 when the user presses the pusher 40 forward. Such a core tube 31 is, for example, formed of resin. In the state where the pusher 40 is not pressed forward (see...) Figures 1-3When the pressing member 42 is pressed forward, the spring force of the pressing body 48 applies a force to the rearward side. Therefore, when the pressing body 40 is not pressed forward, a gap is formed along the axial direction da between the rear end of the lead tube 31 and the inner edge 42c of the pressing member 42. If such a gap is formed between the rear end of the lead tube 31 and the inner edge 42c of the pressing member 42, the lead tube 31 will not move forward even if the pressing body 40 is pressed slightly forward by contact with the inner surface of the bag or other items stored inside the bag when the mechanical pencil 10 is placed in a bag or similar object for transport. Therefore, it is possible to prevent the writing lead 80 from accidentally being ejected from the mechanical pencil 10.

[0035] The chuck 32 is a component that holds the writing refill 80. The chuck 32 can move back and forth integrally with the refill tube 31 and the connector 33. The connector 33 is a component that connects the refill tube 31 and the chuck 32. In the illustrated example, the rear end of the connector 33 is inserted into the front end of the refill tube 31, thereby fixing the connector 33 relative to the refill tube 31. Similarly, the rear end of the chuck 32 is inserted into the front end of the connector 33, thereby fixing the chuck 32 relative to the connector 33.

[0036] A clamping spring 35 is disposed in front of the connector 33. The clamping spring 35 is, for example, a coil spring. A bearing member 36 is disposed in front of the clamping spring 35, with the clamping spring 35 in a compressed state between the front end of the connector 33 and the bearing member 36. The bearing member 36 is a member that bears the elastic force of the clamping spring 35. The bearing member 36 is pressed forward by the elastic force of the clamping spring 35 and abuts against a stepped portion formed on the inner surface of the front end member 26. The fastener 37 is an annular member located radially outward relative to the front portion of the clamp 32. The rear end of the fastener 37 abuts against the bearing member 36, restricting the rearward movement of the fastener 37. A core retainer 38 is disposed in front of the clamp 32 and abuts against the outer surface of the writing core 80 to retain the writing core 80. The core retainer 38 is formed of an elastic component such as rubber, which inhibits the writing core 80 from moving axially when the chuck 32 is not holding the writing core 80.

[0037] The weight body 50 is a cylindrical component extending along the axial direction da. The weight body 50 is disposed on the outside of the core tube 31 in a manner that surrounds the core tube 31. The weight body 50 is formed of a material with relatively high density, such as a metallic material. A gap is formed between the weight body 50 and the core tube 31, allowing the weight body 50 to move easily relative to the core tube 31 along the axial direction da. In particular, when the user swings the mechanical pencil 10 along the axial direction da, the weight body 50 moves relative to the core tube 31 along the axial direction da.

[0038] The connector 33 has an abutment portion 33a that protrudes further outward toward the radial direction dr than the outer peripheral surface of the core tube 31. When the weight body 50 moves forward and collides with the abutment portion 33a of the connector 33 from the rear, the connector 33 moves forward due to the impact load acting from the weight body 50 relative to the connector 33.

[0039] When the writing lead 80 is delivered via the lead delivery mechanism 30, the user presses the actuating body 40 forward. As the actuating body 40 moves forward, the axial dimension da of the gap formed between the rear end of the lead tube 31 and the inner edge 42c of the pressing member 42 of the actuating body 40 decreases. When the inner edge 42c of the pressing member 42 abuts against the rear end of the lead tube 31, and the actuating body 40 is pressed forward, the actuating body 40, lead tube 31, connector 33, and clamp 32 move forward against the elastic force of the actuating body spring 48 and the clamp spring 35. Furthermore, when the user swings the mechanical pencil 10 along the axial dimension da, the weight 50 moves forward and collides with the abutting portion 33a of the connector 33, thereby causing the lead tube 31, connector 33, and clamp 32 to also move forward against the elastic force of the clamp spring 35.

[0040] When the actuating body 40 is not pressed forward, the outer surface of the front portion of the chuck 32 abuts against the fastener 37 from the inside. Therefore, the opening of the front portion of the chuck 32 to the outer side in a radial direction (dr) is prevented. Thus, the front portion of the chuck 32 holds the writing refill 80. If the chuck 32 moves forward, the writing refill 80 held by the chuck 32 moves forward, and the writing refill 80 is delivered forward from the front opening 20a of the shaft cylinder 20. When the chuck 32 moves further forward, the front portion of the chuck 32 moves forward relative to the fastener 37. Thus, the front portion of the chuck 32 opens to the outer side in a radial direction (dr), and the writing refill 80 held by the front portion of the chuck 32 is released. At this time, the writing refill 80 is held by the refill holder 38.

[0041] When the user releases the pressure on the pusher 40, the pusher 40, core tube 31, connector 33, and clamp 32 move rearward due to the elastic force of the pusher force spring 48 and the clamp force spring 35. Similarly, when the weight 50 releases the pressure on the connector 33, the core tube 31, connector 33, and clamp 32 move rearward due to the elastic force of the clamp force spring 35. As the clamp 32 moves rearward, its front portion moves inward toward the fastener 37, abutting against the fastener 37 and holding the writing core 80. At this time, the writing core 80 is held by the core retainer 38, thus suppressing rearward movement of the writing core 80. In this writing instrument embodiment, the writing core 80 is thus conveyed forward from the front opening 20a of the shaft cylinder 20.

[0042] However, in conventional mechanical pencils with a snap-out mechanism, when transported in a bag or similar container, the weight of the pencil may sometimes shift back and forth unexpectedly due to vibration or tilting, causing the writing lead to be ejected. In such cases, the writing lead may break, or the inner surface of the bag or other items stored inside may become soiled due to the ejected or broken writing lead.

[0043] To suppress such problems, the mechanical pencil 10 of this embodiment has a movement limiting mechanism 60 capable of limiting the axial movement da of the weight body 50. The movement limiting mechanism 60 can switch the mechanical pencil 10 to an unrestricted state where the movement of the weight body 50 is not restricted and a restricted state where the movement of the weight body 50 is restricted. Figure 2 This is a longitudinal sectional view showing the movement restriction mechanism 60 in its unrestricted state. Figure 3 This is a longitudinal sectional view showing the movement restriction mechanism 60 in a restricted state.

[0044] exist Figure 2 In the unrestricted state shown, the movable range of the weight body 50 along the axial direction da is greater than that in the restricted state. Therefore, when the mechanical pencil 10 swings along the axial direction da, the weight body 50 moves significantly in the front-rear direction. Therefore, when the weight body 50 collides with the abutting portion 33a of the connector 33, a greater impact load than the impact load acting on the connector 33 from the weight body 50 in the restricted state acts on the connector 33. Therefore, the lead tube 31, the connector 33, and the chuck 32 move forward against the elastic force of the chuck force spring 35, and the writing lead 80 is delivered from the front opening 20a of the cylinder 20.

[0045] On the other hand, Figure 3 Under the restricted state shown, the movable range of the weight body 50 in the axial direction da is narrowed. Therefore, the range of movement of the weight body 50 in the forward and backward direction when the mechanical pencil 10 swings along the axial direction da is narrowed. Consequently, the impact load acting on the connector 33 from the weight body 50 when it collides with the abutment portion 33a of the connector 33 is also less than the impact load acting on the connector 33 from the weight body 50 in the unrestricted state. In this case, the forward movement of the lead tube 31, connector 33, and chuck 32 against the elastic force of the chuck force spring 35 is suppressed, and the writing lead 80 is also suppressed from being ejected from the front opening 20a of the cylinder 20. In this specification, restricting the forward and backward movement of the weight body 50 means that the movable range of the weight body 50 in the axial direction da is narrowed.

[0046] The following is for reference Figures 2-9 The details of the movement restriction mechanism 60 are explained. Figure 4 Is with Figure 3 The cross section view corresponding to line IV-IV, Figure 5This is an exploded perspective view showing a portion of a mechanical pencil 10 including a movement limiting mechanism 60. Figure 6 This is a perspective view showing the main shaft 22 cut along the central axis A. Figure 7 This is a perspective view showing the state in which the rotating component 62 of the movement restriction mechanism 60 is cut off along the central axis A. Figure 8 This is a diagram showing a portion of the movement restriction mechanism 60 in an unrestricted state. Figure 9 This is a diagram showing a portion of the movement restriction mechanism 60 in a restricted state.

[0047] The movement restriction mechanism 60 of this embodiment includes a groove 22a and an inner step 22b provided on the main shaft 22, an operating body 61, a moving part 64, a moving part force-applying spring 66, and a restriction part 68.

[0048] The main shaft 22 of this embodiment has a groove 22a and an inner step 22b. The groove 22a is provided on the inner circumferential surface of the main shaft 22 and extends along the axial direction da. In particular, the groove 22a extends in a straight line. The main shaft 22 may also have multiple grooves 22a. The multiple grooves 22a may also be arranged at equal angular intervals. In the illustrated example, the main shaft 22 includes two grooves 22a that are 180 degrees apart from each other. It is not limited to this; the main shaft 22 may have one groove 22a or more than three grooves 22a. The inner step 22b is a step provided on the inner circumferential surface of the main shaft 22 and includes a rearward-facing surface. The inner step 22b is the portion that bears the elastic force of the moving member force spring 66.

[0049] The operating body 61 is a component operated by the user to switch the mechanical pencil 10 between a non-restricted state and a restricted state. The operating body 61 is mounted on the spindle 22 in a manner that allows rotation about the central axis A but prevents forward and backward movement. In this embodiment, the operating body 61 includes a rear shaft 24 and a rotating member 62. At least a portion of the rear shaft 24 is disposed outside the rear portion of the spindle 22. In the illustrated example, a portion of the front side of the rear shaft 24, including the front end, is disposed outside the rear portion of the spindle 22. The rear shaft 24 is disposed radially outward relative to the rotating member 62. Furthermore, the rear shaft 24 is fixed to the rotating member 62 in a manner that prevents rotation about the central axis A and prevents forward and backward movement. In particular, the rear portion of the rear shaft 24 is fixed to the rear portion of the rotating member 62.

[0050] The rotating component 62 is a component with a generally cylindrical shape. The rotating component 62 is mounted on the main shaft 22 in a manner that allows it to rotate about a central axis A but prevents it from moving back and forth. The rotating component 62 has an inner eave 62a and a cam portion 63. The inner eave 62a is formed to protrude inward from its inner circumference towards a radial direction dr. Figure 2 as well as Figure 3In the illustrated example, the protrusion 42a of the pressing member 42 can be engaged with the front surface of the inner edge portion 62a. With the protrusion 42a engaged with the front surface of the inner edge portion 62a, the rearward movement of the pressing body 40 relative to the rotating member 62 is restricted. The rear surface of the inner edge portion 62a is the portion that bears the elastic force of the pressing body force spring 48. In the illustrated example, the pressing body force spring 48 is disposed between the inner edge portion 62a of the rotating member 62 and the outer edge portion 42b of the pressing member 42 of the pressing body 40.

[0051] The cam portion 63 has the function of cooperating with the abutment portion 64b of the moving member 64 to switch the mechanical pencil 10 to a restricted state and an unrestricted state. Figure 8 and Figure 9 The shape of the cam portion 63 of the rotating component 62 is shown. Figure 8 and Figure 9 This is an unfolded view showing the main shaft 22, rotating component 62, and moving component 64 cut along planes extending axially (da) and radially (dr). Figure 8 and Figure 9 In the image, viewed from the outer side of the radial dr, the groove 22a of the main shaft 22, the cam 63 of the rotating member 62, the protrusion 64a of the moving member 64 (described later), and the abutment 64b are shown.

[0052] The rotating member 62 has at least two cam portions 63. The at least two cam portions 63 may also be arranged with equal angular intervals between them. In the illustrated example, the rotating member 62 has two cam portions 63 with an angular interval of 180 degrees between them. However, the rotating member 62 may also have three or more cam portions 63.

[0053] The cam portion 63 includes a cam inclined surface 63a, a locking recess 63b, and a protrusion 63c. The cam inclined surface 63a is the surface on which the abutment portion 64b moves while abutting during the rotation of the rotating component 62 about the central axis A. The cam inclined surface 63a extends in a spiral shape along directions inclined relative to both the axial direction da and the circumferential direction dc (see reference). Figure 7 ). In the unfolded diagram Figure 8 and Figure 9 In the diagram, the cam inclined surface 63a is shown extending in a straight line along directions inclined relative to both the axial direction da and the circumferential direction dc. However, it is not limited to this; the cam inclined surface 63a may also be arranged in a manner such as... Figure 8 and Figure 9The planar cross-section shown extends in a curved shape along the axial direction da and the radial direction dr. The locking recess 63b is the portion where the abutment portion 64b is located in the restricted state. The locking recess 63b is recessed rearward. The protrusion 63c is a so-called check valve that prevents the abutment portion 64b located in the locking recess 63b from moving towards the cam ramp 63a. The protrusion 63c is located between the cam ramp 63a and the locking recess 63b. The protrusion 63c protrudes forward from the locking recess 63b.

[0054] The inclination angle θ1 of the cam inclined plane 63a relative to the circumferential dc can also be greater than 30 degrees and less than 80 degrees (refer to...). Figure 9 The preferred tilt angle θ1 can be above 40 degrees and below 75 degrees, above 50 degrees and below 70 degrees, or above 60 degrees and below 65 degrees.

[0055] The moving part 64 is a generally cylindrical component disposed within the main shaft 22. The moving part 64 is disposed on the main shaft 22 in a manner that prevents rotation about the central axis A but allows movement along the axial direction da. The moving part 64 is capable of moving back and forth relative to the operating body 61 (rotating part 62). The operating body 61 (rotating part 62) is capable of rotating relative to the moving part 64 about the central axis A. Furthermore, the moving part 64 can be positioned in a restricted position (see reference...). Figure 3 and Figure 9 ) and the unrestricted position behind the restricted position (refer to Figure 2 and Figure 8 The mechanical pencil 10 moves between the moving part 64 and the other part. In this embodiment, when the moving part 64 is in the restricted position, the mechanical pencil 10 is in the restricted state, and when the moving part 64 is in the unrestricted position, the mechanical pencil 10 is in the unrestricted state.

[0056] A protrusion 64a is formed on the outer peripheral surface of the moving member 64, protruding outward toward the radial direction dr. In the illustrated example, the protrusion 64a is provided on the outer peripheral surface of the front portion of the moving member 64. In particular, the moving member 64 has a large-diameter portion located in the front portion and a small-diameter portion located behind the large-diameter portion and having an outer diameter smaller than the outer diameter of the large-diameter portion, and the protrusion 64a is provided on the outer peripheral surface of the large-diameter portion. The protrusion 64a extends linearly along the axial direction da. The protrusion 64a is located within the groove 22a of the main shaft 22 and is configured to be movable along the axial direction da within the groove 22a. Therefore, the protrusion 64a is provided corresponding to each groove 22a of the main shaft 22. The moving member 64 has the same number of protrusions 64a as the groove 22a of the main shaft 22. In the illustrated example, the moving member 64 includes two protrusions 64a spaced 180 degrees apart from each other. In addition, the rear portion of the moving member 64 is located inside the front portion of the rotating member 62.

[0057] An abutment portion 64b is formed on the outer peripheral surface of the moving member 64, intended to abut against the cam portion 63 of the rotating member 62. In the illustrated example, the abutment portion 64b is formed to protrude outward from the outer peripheral surface of the moving member 64 toward the radial direction dr. In the illustrated example, the abutment portion 64b is provided on the outer peripheral surface of the rear portion of the moving member 64. In particular, the abutment portion 64b is provided on the outer peripheral surface of the small-diameter portion of the moving member 64. The abutment portion 64b extends linearly along the axial direction da. The rear end portion of the abutment portion 64b that directly abuts against the cam portion 63 has a curved shape. In particular... Figure 8 and Figure 9 In the example shown, viewed radially (dr), the rear end of the abutment portion 64b has a semi-circular shape. The portion of the abutment portion 64b that directly abuts against the cam portion 63 has a curved shape, thereby allowing the abutment portion 64b to smoothly move along the cam inclined surface 63a while abutting against it.

[0058] The moving member 64 has at least two abutting portions 64b. The at least two abutting portions 64b may also be arranged with an equal angular interval between them. In the illustrated example, the moving member 64 includes two abutting portions 64b with an angular interval θ2 of 180 degrees between them (see reference). Figure 9 (Not limited thereto,) the moving member 64 may also have three or more abutment portions 64b. In this embodiment, the moving member 64 has the same number of abutment portions 64b as the rotating member 62 has cam portions 63 (cam ramps 63a). That is, the mechanical pencil 10 has two cam portions 63 and two abutment portions 64b. Not limited thereto, the mechanical pencil 10 may have three cam portions 63 and three abutment portions 64b, or it may have four cam portions 63 and four abutment portions 64b.

[0059] In a mechanical pencil with only one cam ramp and one abutment, when the operating body rotates, the pressing force is transmitted from the operating body to the moving member at only one location. In this case, the moving member may sometimes tilt relative to the central axis. If the moving member tilts, it may get stuck in the cylinder and may not be able to move back and forth properly. In this embodiment, one of the operating body 61 (rotating member 62) and the moving member 64 has at least two cam ramps 63a, and the other of the operating body 61 (rotating member 62) and the moving member 64 has at least two abutment portions 64b, thereby transmitting the pressing force from the operating body 61 to the moving member 64 at at least two locations. Thus, when pressed by the operating body 61, the tilting of the moving member 64 relative to the central axis A is suppressed. Therefore, the moving member 64 can move back and forth stably relative to the operating body 61. That is, in the mechanical pencil 10, the restricted state and the unrestricted state can be switched stably.

[0060] In this embodiment, the protrusion 64a and the abutment 64b are arranged in the axial direction da (see reference). Figure 5 , Figure 8 as well as Figure 9 In other words, viewed from the axial direction da, the protrusion 64a and the abutment 64b are arranged at the same angle in the circumferential direction dc. In particular, in the illustrated example, viewed from the axial direction da, the protrusion 64a and the abutment 64b are arranged overlapping in the radial direction dr. An inner eave 64c is formed on the inner circumferential surface of the moving member 64, protruding inward toward the radial direction dr. The inner eave 64c is the portion intended to abut against the limiting member 68.

[0061] The moving part force spring 66 is a component that applies a rearward force to the moving part 64. The moving part force spring 66 is, for example, a coil spring. The moving part force spring 66 is disposed in a compressed state between the moving part 64 and the main shaft 22. Specifically, the moving part force spring 66 is disposed between the front end 64d of the moving part 64 and the inner step portion 22b of the main shaft 22. Therefore, the moving part 64 is always subjected to a rearward force relative to the shaft sleeve 20 (main shaft 22).

[0062] The limiting member 68 is a component that restricts the forward and backward movement of the weight body 50 when the moving member 64 is in the limited position, i.e., when the mechanical pencil 10 is in the limited state. More specifically, in the limited state, the limiting member 68 narrows the range of movement of the weight body 50 in the axial direction da. The limiting member 68 is a component with a generally cylindrical shape and is disposed between the rear end of the weight body 50 and the moving member 64. In particular, the limiting member 68 is disposed between the rear end of the weight body 50 and the inner edge 64c of the moving member 64. In the limited state, the moving member 64 is located in a limited position further forward than in the non-limited position. Accompanyingly, the limiting member 68 is also located forward. Therefore, the range of movement of the weight body 50 in the axial direction da is narrowed.

[0063] When the moving part 64 is in the restricted position, the restricting part 68 can contact the rear end of the weight body 50. In this case, even if the mechanical pencil 10 swings along the axis da in the restricted state, the weight body 50 will not move along the axis da. As a result, the weight body 50 will not exert a collision load on the abutment portion 33a of the connector 33, thus suppressing the delivery of the writing lead 80. In addition, since the weight body 50 does not move along the axis da, it is possible to suppress the collision noise caused by the weight body 50 colliding with the connector 33 and the restricting part 68.

[0064] Furthermore, when the moving part 64 is in the restricted position and the weight 50 is at its foremost position, a gap can be formed between the weight 50 and the restricting part 68. In this case, the range of movement of the weight 50 along the axial direction da is also narrowed in the restricted state. Therefore, when the mechanical pencil 10 swings along the axial direction da, the impact load generated by the collision between the weight 50 and the abutment portion 33a of the connector 33 is reduced. As a result, the ejection of the writing lead 80 from the front opening 20a of the cylinder 20 is suppressed.

[0065] The limiting member 68 can also be an elastic member. In this case, even if the weight 50 moves back and forth and collides with the limiting member 68 while in the limited state, it is possible to suppress the generation of collision noise between the weight 50 and the limiting member 68. The elastic member can also be, for example, a coil spring.

[0066] In the restricted state, the restricting member 68 can be positioned in a compressed state between the rear end of the weight body 50 and the moving member 64. At this time, when the moving member 64 is in the restricted position, the pressing force exerted by the restricting member 68 on the weight body 50 is preferably less than the elastic force of the clamping spring 35. Therefore, it is possible to prevent the weight body 50, connector 33, and clamp 32 from moving forward against the elastic force of the clamping spring 35 due to the elastic force of the restricting member 68. Consequently, it is possible to suppress forward movement of the clamp 32 relative to the fastener 37, thereby opening the front portion of the clamp 32 radially outward, reducing the force by which the clamp 32 holds the writing core 80.

[0067] The limiting member 68 may be fixed relative to the moving member 64, or it may not be fixed relative to the moving member 64, but may move back and forth between the moving member 64 and the weight body 50. Alternatively, the limiting member 68 may be integrally formed with the moving member 64.

[0068] Next, the main references are... Figure 2 , Figure 3 , Figure 8 as well as Figure 9 The operation of the movement restriction mechanism 60 will be explained.

[0069] like Figure 2 as well as Figure 8As shown, in the unrestricted state, the moving part 64 is located in an unrestricted position further rearward than the restricted position due to the elastic force of the moving part force spring 66. In this state, the movable range of the weight body 50 in the axial direction da is greater than that in the restricted state. Therefore, when the mechanical pencil 10 swings along the axial direction da, the weight body 50 moves significantly in the front-rear direction. Therefore, when the weight body 50 collides with the abutting portion 33a of the connector 33, an impact load greater than the impact load acting on the connector 33 from the weight body 50 in the restricted state acts on the connector 33 from the weight body 50. Therefore, the lead tube 31, the connector 33, and the chuck 32 move forward against the elastic force of the chuck force spring 35, and the writing lead 80 is delivered from the front opening 20a of the shaft cylinder 20. That is, the writing lead 80 can be delivered by the weight body 50.

[0070] To switch the mechanical pencil 10 from an unrestricted state to a restricted state, in the unrestricted state, the user rotates the rear shaft 24 constituting the operating body 61 relative to the main shaft 22 about the central axis A. This causes the rotating member 62 to rotate together with the rear shaft 24 about the central axis A. In this embodiment, by rotating the rear shaft 24 clockwise relative to the main shaft 22 as viewed from the rear, the user moves the moving member 64 from the unrestricted position to the restricted position, and the mechanical pencil 10 switches from the unrestricted state to the restricted state. As the rotating member 62 rotates, the cam portion 63 of the rotating member 62 moves along the circumferential direction dc. Figure 8 and Figure 9 In the middle, the cam part 63 moves upward along the circumferential direction dc (refer to...) Figure 9 (Hollow arrow).

[0071] The moving part 64 is disposed on the main shaft 22 in a manner that prevents it from rotating about the central axis A but allows it to move axially along the axis da. As the cam portion 63 moves circumferentially dc, the abutting portion 64b of the moving part 64 contacts the cam inclined surface 63a of the cam portion 63 while moving forward along the cam inclined surface 63a. At this time, the moving part force spring 66 disposed between the moving part 64 and the main shaft 22 is compressed by the moving part 64. When the abutting portion 64b exceeds the protrusion 63c of the cam portion 63, the abutting portion 64b is pressed against the locking recess 63b of the cam portion 63 by the elastic force of the compressed moving part force spring 66, and the abutting portion 64b is locked in the locking recess 63b. Thus, the moving part 64 is in a restricted position, and the mechanical pencil 10 is in a restricted state.

[0072] In the restricted state, the range of movement of the weight body 50 in the axial direction da is narrowed by the restricting member 68. That is, the forward and backward movement of the weight body 50 is restricted. Therefore, when the weight body 50 collides with the abutment portion 33a of the connector 33, the impact load acting on the connector 33 from the weight body 50 is reduced. Therefore, the suppressing chuck 32 moves forward against the elastic force of the chuck force spring 35. As a result, the suppressing writing core 80 is ejected from the front opening 20a of the shaft cylinder 20.

[0073] When switching from a restricted state to an unrestricted state, in the unrestricted state, the user rotates the operating body 61 in the opposite direction around the central axis A. In this embodiment, the user rotates the rear shaft 24 counterclockwise relative to the main shaft 22 as viewed from the rear. By rotating the operating body 61 (rotating member 62), the cam portion 63 of the rotating member 62 moves along the circumferential direction dc. Figure 8 and Figure 9 In the middle, the cam portion 63 moves downward along the circumferential direction dc. When the abutting portion 64b of the moving member 64 passes the protrusion 63c of the cam portion 63, the moving member 64 is pressed backward by the force of the force-applying spring 66. As a result, the abutting portion 64b presses the cam inclined surface 63a backward, and the cam inclined surface 63a rotates about the central axis A while abutting the abutting portion 64b. As a result, the moving member 64 is in the unrestricted position, and the mechanical pencil 10 is in the unrestricted state.

[0074] When the mechanical pencil 10 has two cam portions 63 and two abutment portions 64b, the angular interval θ3 between the angle of the abutment portion 64b in the circumferential direction dc when the moving member 64 is in the unrestricted position and the angle of the abutment portion 64b in the circumferential direction dc when the moving member 64 is in the restricted position can, for example, be more than 90 degrees and less than 170 degrees (see reference). Figure 9 Preferably, the angular interval θ3 can be 100 degrees or more and 160 degrees or less, 110 degrees or more and 150 degrees or less, or 120 degrees or more and 140 degrees or less.

[0075] The mechanical pencil 10 of this embodiment includes: a cylinder 20 containing a main shaft 22; a lead feeding mechanism 30 for feeding a writing lead 80; a weight 50 configured to move back and forth relative to the main shaft 22; an operating body 61 rotatable about a central axis A relative to the main shaft 22; a moving member 64 configured to move back and forth relative to the operating body 61 and to move between a restricted position and a non-restricted position further rearward than the restricted position; a restricting member 68 restricting the back and forth movement of the weight 50 when the moving member 64 is in the restricted position; at least two cam ramps 63a disposed on one of the operating body 61 and the moving member 64; and at least two abutment portions 64b disposed on the other of the operating body 61 and the moving member 64, wherein when the operating body 61 rotates about the central axis A, the cam ramps 63a and the abutment portions 64b come into contact with each other, and the abutment portions 64b move along the cam ramps 63a.

[0076] According to this mechanical pencil 10, when the moving part 64 is in the restricted position, the forward and backward movement of the weight 50 is restricted by the restricting part 68. Therefore, when the weight 50 collides with the abutment portion 33a of the connector 33, the impact load acting on the connector 33 from the weight 50 is reduced. Therefore, the chuck 32 is prevented from moving forward against the elastic force of the chuck force spring 35. As a result, the writing lead 80 is prevented from being ejected from the front opening 20a of the cylinder 20.

[0077] Furthermore, in this mechanical pencil 10, one of the operating body 61 (rotating member 62) and the moving member 64 has at least two cam inclined surfaces 63a, and the other of the operating body 61 (rotating member 62) and the moving member 64 has at least two abutment portions 64b, thereby transmitting pressing force from the operating body 61 to the moving member 64 at at least two locations. Thus, when pressed by the operating body 61, the tilting of the moving member 64 relative to the central axis A is suppressed. Therefore, the moving member 64 can move stably back and forth relative to the operating body 61. That is, in the mechanical pencil 10, the restricted state and the unrestricted state can be stably switched.

[0078] In the mechanical pencil 10 of this embodiment, the operating body 61 includes a rear shaft 24, at least a portion of which is disposed on the outer side of the rear portion of the main shaft 22.

[0079] With this mechanical pencil 10, the user can operate the control unit 61 without picking up the mechanical pencil 10 when switching between the unrestricted and restricted states. Therefore, it is possible to easily switch between the unrestricted and restricted states.

[0080] In the mechanical pencil 10 of this embodiment, the lead delivery mechanism 30 includes: a chuck 32 that holds the writing lead 80; and a chuck force spring 35 that applies a force to the chuck 32 backward. When the moving member 64 is in the restricted position, the pressing force of the restricting member 68 pressing the weight body 50 forward is less than the elastic force of the chuck force spring 35.

[0081] According to this mechanical pencil 10, it is possible to prevent the weight body 50, connector 33, and chuck 32 from moving forward due to the elasticity of the limiting member 68 resisting the elasticity of the chuck force spring 35. Therefore, it is possible to prevent the chuck 32 from moving forward relative to the fastener 37, thereby opening the front portion of the chuck 32 radially outward, and reducing the force by which the chuck 32 holds the writing lead 80.

[0082] In the mechanical pencil 10 of this embodiment, when the moving part 64 is in the restricted position and the weight body 50 is in the foremost position, a gap is formed between the weight body 50 and the restricted part 68.

[0083] According to this mechanical pencil 10, in the restricted state, the range of movement of the weight body 50 along the axial direction da is also narrowed. Therefore, when the mechanical pencil 10 swings along the axial direction da, the impact load generated by the collision between the weight body 50 and the abutment portion 33a of the connector 33 is reduced. As a result, the writing lead 80 is prevented from being ejected from the front opening 20a of the cylinder 20.

[0084] In the mechanical pencil 10 of this embodiment, the limiting member 68 is an elastic member.

[0085] In the mechanical pencil 10 of this embodiment, the elastic component is a coil spring.

[0086] According to such a mechanical pencil 10, even if the weight body 50 moves back and forth and collides with the limiting member 68 in the restricted state, the collision sound generated between the weight body 50 and the limiting member 68 can be suppressed.

[0087] The mechanical pencil 10 of this embodiment has a moving part force spring 66 that applies force to the moving part 64 in the rearward direction.

[0088] In this mechanical pencil 10, the moving part 64 is always subjected to a rearward force relative to the cylinder 20 (main shaft 22). This ensures that the abutting portion 64b of the moving part 64 is always pressed against the cam portion 63. Therefore, the abutting portion 64b properly contacts the cam inclined surface 63a of the cam portion 63, enabling stable back-and-forth movement of the moving part 64.

[0089] In the mechanical pencil 10 of this embodiment, the spindle 22 has a groove 22a provided on the inner circumferential surface and extending axially, and the moving member 64 has a protrusion 64a that can move within the groove 22a.

[0090] According to such a mechanical pencil 10, the moving part 64 can be guided by the groove 22a, so that the moving part 64 can move back and forth appropriately.

[0091] In the above embodiment, an example was described where the operating body 61 of the mechanical pencil 10 has a cam inclined surface 63a and the moving member 64 has an abutment portion 64b. However, this is not a limitation; the operating body 61 may also have an abutment portion and the moving member 64 may have a cam inclined surface. Even in this case, the mechanical pencil 10 can achieve the same effect as the above embodiment.

[0092] Furthermore, in the above embodiment, the rear shaft 24 constitutes part of the operating body 61, but the structure of the operating body 61 is not limited to this. For example, an annular member capable of rotating around the central axis A may be arranged between the main shaft and the rear shaft 24, and the operating body 61 may be constituted by the annular member and the rotating member 62. In this case, the annular member may also be fixed to the rotating member 62 in a manner that prevents it from rotating around the central axis A and from moving back and forth. Even in this case, the user can operate the operating body 61 without picking up the mechanical pencil 10 when switching between the unrestricted state and the restricted state. Therefore, it is possible to easily switch between the unrestricted state and the restricted state.

Claims

1. A mechanical pencil, comprising: A shaft sleeve, which includes a main shaft; The chip delivery mechanism delivers the writing chip; A weight body configured to move back and forth relative to the main shaft; An operating body that is capable of rotating about a central axis relative to the main shaft; A movable component configured to move back and forth relative to the operating body, and to move between a restricted position and an unrestricted position further rearward than the restricted position; A limiting component that restricts the forward and backward movement of the weight body when the moving component is in the limiting position; At least two cam ramps are disposed on one of the operating body and the moving component; as well as At least two abutting portions are disposed on the other side of the operating body and the moving component. When the operating body rotates about the central axis, the cam inclined surface comes into contact with the abutment portion, and the abutment portion moves along the cam inclined surface. The limiting component is an elastic component.

2. The mechanical pencil according to claim 1, wherein, The operating body includes a rear shaft, at least a portion of which is disposed on the outer side of the rear portion of the main shaft.

3. The mechanical pencil according to claim 1 or 2, wherein, The core delivery mechanism has the following features: The chuck holds the writing core. as well as A clamping spring applies a force to the clamps backward. When the moving part is in the restricted position, the pressing force of the restricting part on the weight body is less than the elastic force of the clamping spring.

4. The mechanical pencil according to claim 1 or 2, wherein, When the moving part is in the restricted position and the weight body is at the foremost position, a gap is formed between the weight body and the restricted part.

5. The mechanical pencil according to claim 1 or 2, wherein, The elastic component is a helical spring.

6. The mechanical pencil according to claim 1 or 2, wherein, The mechanical pencil has a moving part force spring that applies a force to the moving part in the rearward direction.

7. The mechanical pencil according to claim 1 or 2, wherein, The spindle has a groove on its inner circumferential surface that extends axially. The movable component has a protrusion that is capable of moving within the groove.

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