JP2019119110A - mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical pencil of a haunting type capable of avoiding an erroneous operation when the base is haunted from a shaft cylinder and capable of performing a haunting operation of the cap with a light force. A mechanical pencil 100 is supported in a shaft cylinder 10, an operating body 40 exposed from the shaft cylinder 10, a pressing operation unit 18 held by the operating body 40, and a writing core 21. It is provided with a lead feeding unit 20 for holding. When the operating body 40 is pushed forward to the predetermined position X with respect to the barrel 10, the core feeding unit 20 is alternately held by the barrel 10 in a relatively front writing state and a relatively rear non-writing state. .. When the pressing operation unit 18 is pushed forward with respect to the barrel 10, the writing core 21 is sent forward from the core feeding unit 20. When the pressing operation unit 18 is pressed forward in the non-writing state, the operating body 40 is restricted from moving forward with respect to the barrel 10 at a position behind the predetermined position X. [Selection diagram] Fig. 1

Description

  The present invention relates to a mechanical pencil capable of writing by drawing out a writing core from a front end of a die by a predetermined amount by knocking operation or the like.

  A retractable mechanical pencil is known, in which an operating body protruding rearward from the rear end of the barrel is pushed forward (relatively moved) to a predetermined position with respect to the barrel to make the cap project from the front end of the barrel. . Generally, the base is attached to the front end of the lead-out unit that holds the writing core. Then, when the operating body is pushed forward to a predetermined position with respect to the barrel, the core feeding unit is alternately positioned in the writing state relative to the barrel relative to the writing state and in the non-writing state relative to the rear It is supposed to be As a result, by pushing the operating body, the operation of projecting and retracting the base from the front end of the barrel is alternately performed. Such an appearance type retractable mechanical pencil is described, for example, in Patent Document 1 below.

  In general, the push-and-push type mechanical pencil is provided with a pressing operation unit for performing an operation of drawing out the writing core on the operation body. The pressing operation unit is movable relative to the operating body back and forth, and when the core feeding unit is in the writing state, the pressing operating unit is pushed forward with respect to the barrel and the operating body from the core feeding unit The writing core is sent forward.

  By the way, the force for pressing the pressing operation portion forward with respect to the shaft cylinder is also transmitted to the operating body. For this reason, when the pressing operation portion is pushed forward with respect to the barrel, the operating body is also pushed forward with respect to the barrel. As a result, the operating body is undesirably pushed to the predetermined position and the lead-out unit switches from the writing state to the non-writing state although the pressing operation unit is pushed in to draw out the writing core at the time of writing. There was a case that an erroneous operation occurred.

  In order to prevent such an erroneous operation, for example, it may be considered that a greater force is required to push the operating body to the predetermined position. However, in this case, when the lead-out unit is switched from the writing state to the non-writing state or from the non-writing state to the writing state, it is inconvenient because it is necessary to push the operating body with a strong force.

JP, 2009-208424, A

  The present invention has been made in view of the above circumstances. That is, an object of the present invention is to provide a retractable mechanical pencil capable of avoiding an erroneous operation at the time of bringing a base into and out of a barrel and capable of performing an operation of making and taking out the base with a light force.

The present invention relates to a shaft cylinder,
An operating body exposed from the barrel and movable relative to the barrel in the axial direction;
A pressing operation unit held by the operating body so as to be movable relative to the operating body in the axial direction;
And a core feeding unit supported in the cylinder so as to be relatively movable in the axial direction of the cylinder and holding a writing core,
When the operating body is pushed forward to a predetermined position with respect to the shaft cylinder, the core feeding unit is alternately held by the shaft cylinder in a relatively forward writing state and a relatively backward non-writing state,
When the pressing operation unit is pushed forward with respect to the barrel, the writing core is fed forward from the core feeding unit,
When the pressing operation unit is pressed forward in the non-writing state, the operating body is a mechanical pencil whose forward relative movement with respect to the barrel is restricted at a position behind the predetermined position.

In the above mechanical pencil, the core feeding unit is
A chuck support unit movable relative to the shaft cylinder in the axial direction;
A chuck unit supported by the chuck support unit so as to be relatively movable in the axial direction with respect to the chuck support unit, and holding the writing core so as to be able to be fed forward;
The operating body presses the chuck support unit from the rear,
The pressing operation unit may press the chuck unit from behind.

The operating body is a slide cam that moves relative to the shaft cylinder in the axial direction;
A cam follower, disposed inside the barrel, movable relative to the barrel in the axial direction and rotatable around the axis;
A movable body disposed in front of the cam follower inside the barrel and movable relative to the barrel in the axial direction;
And a biasing means for biasing the chuck support unit forward with respect to the movable body,
The operating body may press the chuck supporting unit from the rear via the cam follower, the movable body, and the biasing unit.

  Further, the distance between the position of the operating body and the predetermined position when the lead-out unit is in the non-writing state is the distance by which the chuck support unit can move forward relative to the shaft cylinder, and the chuck support The sum of the distance with which the chuck unit can move forward relative to the unit may be larger.

The mechanical pencil described above is supported in front of the core feeding unit, and has a mouthpiece having an opening through which the writing core held by the core feeding unit can pass.
And an elastic body disposed in a compressed state between the lead-out unit and the mouthpiece,
When the lead-out unit is in the writing state, the base may press the barrel from behind.

  Furthermore, the axial cylinder may move the lead-out unit relative to the axial cylinder with respect to the axial cylinder by the radial direction component of the axial cylinder of the writing pressure.

  According to the present invention, it is possible to provide an emergent-type mechanical pencil which can avoid an erroneous operation at the time of bringing a base into and out of a barrel and can perform an operation of making and taking out the base with a light force.

It is a schematic longitudinal cross-sectional view which shows the mechanical pencil by one embodiment of this invention when a core feeding unit is in a writing state. It is a schematic longitudinal cross-sectional view which shows the mechanical pencil of FIG. 1 when a core feeding unit is in a non-writing state. It is a schematic longitudinal cross-sectional view which shows the back cylinder of the mechanical pencil of FIG. It is a schematic longitudinal cross-sectional view which decomposes | disassembles and shows the operation body of the mechanical pencil of FIG. It is a schematic front view which shows the cam follower of the mechanical pencil of FIG. It is a schematic longitudinal cross-sectional view which shows the mechanical pencil of FIG. 1 when strong writing pressure is not acting on a writing core at the time of writing. It is a schematic longitudinal cross-sectional view which shows the mechanical pencil of FIG. 1 when strong writing pressure is acting on a writing core at the time of writing.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  1 and 2 are schematic vertical sectional views showing a mechanical pencil 100 according to an embodiment of the present invention. FIG. 1 shows the mechanical pencil 100 when the lead-out unit 20 is in the writing state, and FIG. 2 shows the mechanical pencil 100 when the lead-out unit 20 is in the non-writing state.

  As shown in FIGS. 1 and 2, the mechanical pencil 100 is exposed from the shaft cylinder 10 and the shaft cylinder 10, and the operating body 40 is movable relative to the shaft cylinder 10 in the axial direction da, and the shaft cylinder 10 And a core feeding unit 20 which is supported in the barrel 10 so as to be movable relative to each other in the axial direction da and holds the writing core 21. The operating body 40 according to the present embodiment partially protrudes rearward from the opening at the rear end of the barrel 10. Furthermore, the mechanical pencil 100 has a pressing operating portion 18 held by the operating body 40 so as to be movable relative to the operating body 40 in the axial direction da. As shown in FIG. 1 and FIG. 2, the pressing operation unit 18 is attached to the rear of the operating body 40.

  In the core feeding unit 20, the operating body 40 is pushed forward (relatively moved) to the predetermined position X with respect to the barrel 10, whereby a writing state relatively forward by the barrel 10 (see FIG. 1); The relatively backward non-writing state (see FIG. 2) is alternately held (switched). In the present specification, the position of the operating body 40 with respect to the barrel 10 means the position of the front end (left end in FIGS. 1 and 2) of the operating body 40 with respect to the barrel 10. The configuration for realizing such switching will be described below with reference to FIGS. 1 to 2 and FIGS. 3 to 5.

  3 is a schematic longitudinal sectional view showing the back cylinder 12 of the mechanical pencil 100 of FIG. 1, and FIG. 4 is a schematic longitudinal sectional view showing the operating body 40 of the mechanical pencil 100 of FIG. 5 is a schematic front view showing the cam follower 70 of the mechanical pencil 100 of FIG.

  As shown in FIGS. 1 to 3, the barrel 10 has a front barrel 11 and a rear barrel 12 connected to the rear of the front barrel 11. In the present embodiment, the front cylinder 11 and the rear cylinder 12 are screwed. As shown in FIG. 3, the rear cylinder 12 has an abutted portion 12 a on the inner surface. The abutted portion 12a is a non-parallel and non-perpendicular slope with respect to the axial direction da. The abutted portion 12 a is formed at the front end of the plurality of inner ribs 12 r extending along the axial direction da on the inner surface of the barrel 10. As shown in FIG. 3, a predetermined gap 12g is provided in the circumferential direction of the barrel 10 between the adjacent inner ribs 12r. At least one of the gaps 12g between the adjacent inner ribs 12r is provided with a cam follower restricting portion 12b provided at the front and an operating body restricting portion 12c provided at the rear. Each of the restriction portions 12b and 12c is formed as an abutting surface facing the front.

  Next, as shown in FIG. 4, the operating body 40 has an operating lever 41 and a slide cam 42 connected to the front of the operating lever 41. The control lever 41 has a control lever main body 41m formed in a cylindrical shape, and a clip portion 41c integrally formed on the outer peripheral surface of the control lever main body 41m. An engagement hole 41e is provided on the outer peripheral surface of the operation lever main body 41m. On the other hand, the slide cam 42 is provided at the rear with a projection 42e engaged with the engagement hole 41e of the operation lever main body 41m. Although FIG. 4 shows the operating lever main body 41m and the slide cam 42 in a disassembled state, in an actual mechanical pencil 100, as shown in FIGS. 1 and 2, the engagement hole 41e and the projection 42e The control lever main body 41m and the slide cam 42 are assembled by the engagement of the above. Further, the slide cam 42 has, at its rear end, a plurality of cam side pressing portions 42p for pressing a pressed portion 72p of a cam follower 70 described later. The cam side pressing portion 42p is formed as a projecting lower projection forward, and a valley portion 42m recessed rearward is formed between the adjacent cam side pressing portions 42p. The phase around the axis L of the cam side pressing portion 42p and the phase around the axis L of the gap 12g between the abutted portions 12a are the same, and the phase around the axis L of the valley 42m and the abutted portion The phase around the axis L of 12a is the same.

  A plurality of raised portions 42 u are provided on the front outer peripheral surface of the slide cam 42. The width of each raised portion 42u is slightly smaller than the width g (see FIG. 3) of the gap 12g between the adjacent inner ribs 12r of the back cylinder 12. By positioning the protuberance 42u in the gap 12g, relative rotation of the operating body 40 about the axis L with respect to the barrel 10 (rear barrel 12) is restricted. Further, the raised portion 42 u has an outer diameter that interferes with the operation body restricting portion 12 c of the rear cylinder 12. For this reason, the operation body 40 can be disposed in the retaining state with respect to the shaft cylinder 10 by positioning the raised portion 42u in the gap 12g.

  Next, as shown in FIG. 5, the cam follower 70 according to the present embodiment has a cylindrical cam follower main body 71 and an outer rib 72 integrally formed on the rear outer surface of the cam follower main body 71. There is. The four outer ribs 72 according to the present embodiment are provided at equal intervals along the circumferential direction of the barrel 10. At the rear end of each outer rib 72, a pressed portion 72p is provided. The pressed portion 72p has a non-parallel and non-perpendicular slope with respect to the axial direction da. The pressed portion 72p is in contact with the cam side pressing portion 42p of the slide cam 42 from the front when the core feeding unit 20 is in the non-writing state. The width w of the outer rib 72 is slightly smaller than the width g of the gap 12 g between the adjacent inner ribs 12 r of the back cylinder 12.

  Returning to FIG. 1 and FIG. 2, the mechanical pencil 100 is disposed inside the barrel 10, and the moving body 50 that can be relatively moved forward with respect to the barrel 10, and the core feeding unit 20 with respect to the moving body 50. And a biasing means 60 for biasing forward. The core feeding unit 20 is configured to press the barrel 10 from the rear by the biasing force of the biasing unit 60 when in the writing state. The movable body 50 is cylindrical, and its rear end abuts on the front end of the cam follower 70. Furthermore, the moving body 50 has a bulging portion 52 on the inner surface. The movable body 50 is configured to be moved forward relative to the shaft cylinder 10 by relative movement forward of the operating body 40 relative to the shaft cylinder 10.

  On the outer surface of the rear end of the movable body 50, a flange portion 51 extending outward in the radial direction of the movable body 50 is formed. Furthermore, on the inner surface of the barrel 10, a first receiving portion 13 facing the flange portion 51 from the front is formed. The coil spring 61 is disposed in a compressed state between the flange portion 51 and the first receiving portion 13. Due to the biasing force of the coil spring 61, the protruding portion 42u of the operating body 40 presses the operating body restricting portion 12c from the front via the moving body 50 and the cam follower 70. With such a configuration, the operation body 40 presses the chuck support unit 27 from the rear via the cam follower 70, the moving body 50, and the biasing means 60. Furthermore, the pressing operation unit 18 presses the chuck unit 28 from the rear.

  In the present embodiment, the distance between the position Y (see FIG. 2) of the operation body 40 and the predetermined position X when the lead-out unit 20 is in the non-writing state is that the chuck support unit 27 The sum of the distance of relative movement and the distance of relative movement of the chuck unit 28 forward with respect to the chuck support unit 27 is set larger. In other words, when the lead-out unit 20 is in the non-writing state, the chuck unit 28 is positioned most forward with respect to the barrel 10 by pushing the pressing operation portion 18 forward with respect to the barrel 10. It is positioned so as to be ahead of the position Z (see FIG. 2) of the operating body 40 at the time of the movement. By this, when the pressing operation unit 18 is pushed forward with respect to the barrel 10 when the lead-out unit 20 is in the non-writing state, the operating body 40 is pivoted at the position Z behind the predetermined position X described above. The forward relative movement with respect to the cylinder 10 is limited.

  The core feeding unit 20 according to the present embodiment is relatively movable in the axial direction da with respect to the chuck supporting unit 27 biased forward with respect to the moving body 50 by the biasing unit 60 described above, and the chuck supporting unit 27. The chuck support unit 27 has a chuck unit 28 supported by the chuck support unit 27 and capable of holding the writing core 21 forward. Therefore, the chuck support unit 27 is movable relative to the barrel 10 in the axial direction da with the movable body 50. Furthermore, as shown in FIGS. 1 and 2, the chuck unit 28 has an abutting portion 29 p which is disposed to penetrate through the inside of the movable body 50 and the cam follower 70 and abuts on the bulging portion 52 of the movable body 50 from the rear. doing. The contact portion 29 p of the present embodiment is a raised portion formed on the outer surface of the connector 29. The outer diameter of the contact portion 29 p is larger than the inner diameter of the bulging portion 52 of the movable body 50. Therefore, the relative movement of the chuck unit 28 with respect to the moving body 50 in the forward direction is restricted by the abutment portion 29p coming into contact with the bulging portion 52 from the rear. In the present embodiment, when the lead-out unit 20 is in the writing state, the bulging portion 52 and the contact portion 29p are separated, and when the lead-out unit 20 is in the non-writing state, contact with the bulging portion 52 It comes in contact with the portion 29p.

  As shown in FIGS. 1 and 2, the mechanical pencil 100 further includes a weight body 90 which is disposed inside the barrel 10 and performs a drawing operation of drawing out the writing core 21 by an inertia force. The weight body 90 is arranged to be movable relative to the lead-out unit 20 in the axial direction da. When the lead-out unit 20 is in the writing state, as described above, since the bulging portion 52 and the contact portion 29p are separated, the chuck unit 28 can move forward relative to the chuck support unit 27. There is. In this case, the writing core 21 can be extended by the weight body 90. On the other hand, when the lead-out unit 20 is in the non-writing state, the chuck unit 28 moves forward relative to the chuck support unit 27 because the bulging portion 52 and the contact portion 29p are in contact as described above. Is limited. In this case, extension of the writing core 21 by the weight body 90 is impossible.

  Further, as shown in FIG. 1 and FIG. 2, the mechanical pencil 100 further has a mouthpiece 30 supported in front of the lead-out unit 20. The base 30 has an opening 30 a through which the writing core 21 held by the core feeding unit 20 can pass. A mouthpiece spring 33 as an elastic body is disposed in a compressed state between the lead-out unit 20 and the mouthpiece 30. The base 30 has a guide pipe 31 for guiding the writing core 21 and a sleeve portion 32 larger in diameter than the guide pipe 31. The sleeve portion 32 has a front small diameter portion 32c and a rear large diameter portion 32d. The core feeding unit 20 further includes a cylindrical holding member 22 in order to hold the mouthpiece 30 in the chuck support unit 27 in a state of being retained.

  The holding member 22 is fixed to the chuck support unit 27 in a state of surrounding the outer periphery of the mouthpiece 30. The front end of the holding member 22 has a narrowed portion 22f whose inner diameter is reduced. A tapered portion 22t which is tapered forward is formed on the outer surface of the narrowed portion 22f. The inner diameter of the front end of the narrowed portion 22f is larger than the outer diameter of the small diameter portion 32c of the mouthpiece 30, but smaller than the outer diameter of the enlarged diameter portion 32d. As a result, the enlarged diameter portion 32 d of the mouthpiece 30 inserted from behind into the holding member 22 is prohibited from moving relative to the holding member 22 forward beyond the narrowed portion 22 f.

  The chuck support unit 27 has a second receiving portion 27 a which receives the biasing force of the nozzle spring 33 described above. The second receiving portion 27a is located rearward of the connection portion between the small diameter portion 32c and the enlarged diameter portion 32d of the mouthpiece 30, and the mouthpiece spring 33 is disposed in a compressed state in an expandable and contractible manner with the connection portion. There is. Therefore, the cap 30 is disposed in front of the chuck support unit 27 in a state where the enlarged diameter portion 32 d presses the narrowed portion 22 f of the holding member 22. In the present embodiment, the initial acting load of the base spring 33 is set smaller than the initial acting load of the biasing means 60. When the lead-out unit 20 is in the writing state, the cap 30 presses the barrel 10 from the rear by the action of the spring 33 for the cap.

  In addition, the chuck support unit 27 is supported by the outer cylinder 27p and the outer cylinder 27p, and urges the tightening unit 25 for tightening the chuck 24 provided on the chuck unit 28 and the chuck unit 28 rearward with respect to the outer cylinder 27p. And a return spring 26. The outer cylinder 27p has a reduced diameter portion 27s on the front inner peripheral surface. The chuck 24 is disposed so as to penetrate the opening defined by the reduced diameter portion 27s in the axial direction da, and is movable relative to the outer cylinder 27p in the axial direction da. The return spring 26 is disposed in a compressed state between the reduced diameter portion 27s of the outer cylinder 27p and the connector 29. With such a configuration, the return spring 26 biases the chuck unit 28 rearward with respect to the outer cylinder 27p. When the chuck unit 28 is not moved forward relative to the chuck support unit 27, the chuck 24 clamps the writing core 21 so that the front end region is tightened by the tightening ring 25.

  The barrel 10 (front barrel 11) has a pressing portion 15 with which the tapered portion 22t of the holding member 22 abuts from the rear to the inner peripheral surface, and a barrel-side reduced diameter portion with the small diameter portion 32c of the mouthpiece 30 from the rear And 16). As shown in FIGS. 1 and 2, each of the pressing portion 15 and the barrel-side reduced diameter portion 16 in the present embodiment is a convex portion formed on the inner surface of the barrel 10. Further, the inner diameter of the region corresponding to the holding member 22 of the shaft cylinder 10 is larger than the outer diameter of the holding member 22, and relative movement of the mouthpiece 30 with respect to the shaft cylinder 10 in the radial direction is permitted.

  Further, the pressing operation portion 18 of the present embodiment has a holder portion 18 h which holds the eraser 80 in a rear portion so as to be removable. A dome-shaped knob 81 covering the rear of the eraser 80 is attached to the holder 18 h.

  Next, the operation of the mechanical pencil 100 will be described. In the following description, the state of FIG. 2 in which the base 30 is inserted into the barrel 10 is taken as an initial state.

  Prior to writing on the paper surface, the knob 81 and the eraser 80 are removed from the pressing operation unit 18 and the writing core 21 is inserted into the core pipe 23 as necessary. Thereafter, the knob 81 and the eraser 80 are attached again to the pressing portion 18. Then, by pushing the control lever 41 forward with respect to the barrel 10, the mouthpiece 30 is drawn out from the front end of the barrel 10 as follows. That is, the slide cam 42 and the movable body 50 coupled to the operation lever 41 move forward relative to the barrel 10 while compressing the coil spring 61. During this relative movement, the slide cam 42 is relatively forwardly moved relative to the barrel 10 without rotating around the axis L because the ridges 42 u are guided by the gap 12 g between the inner ribs 12 r of the barrel 10. Moving. Furthermore, since the outer rib 72 of the cam follower 70 is also guided by the gap 12g, it moves forward relative to the barrel 10 without rotating relative to the axis L.

  When the movable body 50 is moved forward relative to the barrel 10, the lead-out unit 20 and the cap 30 move forward relative to the barrel 10 together with the biasing means 60. Then, in the process of this relative movement, first, the small diameter portion 52 d of the mouthpiece 30 abuts on the barrel-side reduced diameter portion 16, and the further relative movement of the mouthpiece 30 relative to the barrel 10 is restricted. In this state, when the moving body 50 is moved relative to the barrel 10 further forward, the mouthpiece spring 33 is compressed, and the length of the small diameter portion 52d projecting forward from the front end of the holding member 22 decreases. Thereafter, the tapered portion 22 t of the holding member 22 abuts against the pressing portion 15 of the barrel 10 from the rear, and further relative movement of the chuck support unit 27 relative to the barrel 10 to the front and the rear of the mouthpiece 30 against the holding member 22 Both of the relative movement of the Then, when the movable body 50 is moved relative to the barrel 10 further forward by the operation lever 41, the movable body 50 is relative to the barrel 10 and the core feeding unit 20 forward while compressing the biasing means 60. Moving. By this relative movement, the bulging portion 52 of the moving body 50 and the contact portion 29p of the chuck unit 28 separate from each other.

  Then, when the control lever 41 is further pushed forward to the barrel 10, the outer ribs 72 of the cam follower 70 come forward from the gap 12g between the inner ribs 12r. As a result, the cam follower 70 is allowed to rotate relative to the barrel 10 about its axis L. As a result, the cam follower 70 rotates relative to the barrel 10 around the axis L by the force with which the cam side pressing portion 42 p of the slide cam 42 presses the pressed portion 72 p of the outer rib 72. In this relative rotation, the outer rib 72 of the cam follower 70 is positioned at the valley 42 m of the slide cam 42 and stops. Thus, the phase around the axis L of the cam follower 70 matches the phase of the abutted portion 12 a of the rear cylinder 12.

  Then, the pressing force applied to the operating lever 41 is weakened, and the moving body 50, the cam follower 70 and the operating body 40 start relative movement rearward with respect to the barrel 10 by the biasing force of the biasing means 60 and the coil spring 61. Do. However, as described above, since the phase around the axis L of the cam follower 70 matches the phase of the gap 12g between the abutted portions 12a, the cam follower 70 slightly retracts relative to the barrel 10 Then, the outer rib 72 abuts on the abutted portion 12a. Then, due to the inclination of the abutted portion 12a, the outer rib 72 is guided until it abuts on the cam follower restricting portion 12b from the front. That is, the moving body 50 and the cam follower 70 are restricted from further rearward relative movement with respect to the barrel 10. As a result, the core feeding unit 20 is put into the writing state, and the operation of causing the mouthpiece 30 to project from the front end of the barrel 10 is completed (see FIG. 1).

  Further, as understood from the above description, when the core feeding unit 20 is in the writing state, the biasing portion 60 of the biasing member 60 causes the tapered portion 22t of the holding member 22 to move the pressing portion 15 of the barrel 10 from behind. Press. Further, the small diameter portion 32 c of the mouth ring 30 presses the barrel-side reduced diameter portion 16 of the barrel 10 from the rear by the biasing force of the mouthpiece spring 33.

  Thereafter, the pressing operation portion 18 (knob 81) is pushed forward (knocked) with respect to the barrel 10 in a posture in which the front end of the barrel 10 is positioned below the pressing operation portion 18. As a result, the chuck unit 28 is advanced with respect to the chuck support unit 27 against the biasing force of the return spring 26. In the process of this advancement, the clamp ring 25 is disengaged from the chuck 24 and the chuck 24 is released. As a result, the writing core 21 is drawn forward from the chuck 24 by a predetermined length.

  Then, the user holds the shaft cylinder 10 and writing is performed by moving the shaft cylinder 10 as desired while bringing the writing core 21 into contact with the paper surface. When the writing core 21 wears, pressing the pressing operation portion 18 forward or swinging the shaft cylinder 10 back and forth to cause the connector 29 to act on the inertia force applied to the weight body 90 (swing The writing core 21 may be drawn out by the operation).

  By the way, when the pressing operation portion 18 instead of the operating body 40 is pushed forward with respect to the shaft cylinder 10, the coil spring 61 is compressed by the moving body 50, and the base 30, the pressing operation portion 18, the operating body 40, the cam follower 70, the moving body 50 and the core feeding unit 20 simultaneously move forward relative to the barrel 10. In the process of this relative movement, first, the mouthpiece 30 abuts on the barrel-side reduced diameter portion 16 of the barrel 10 to restrict further forward relative movement with respect to the barrel 10. In this state, when the pressing operation portion 18 is further pushed forward with respect to the barrel 10, the base spring 33 is compressed, and the holding member 22 abuts against the pressing portion 15 of the barrel 10 and the holding member 22 with respect to the barrel 10 Further forward relative movement is restricted. Then, when the pressing operation portion 18 is further pushed forward with respect to the barrel 10, the coil spring 61 and the biasing means 60 are compressed, and the moving body 50 and the chuck unit 28 move relatively forward with respect to the barrel 10. During this relative movement, the chuck 24 advances relative to the chuck support unit 27, but the chuck 24 abuts against the chuck support unit 27 from the rear side, thereby providing a further forward relative to the chuck support unit 27. Movement is regulated. In other words, further relative movement of the chuck unit 28 and the pressing operation unit 18 with respect to the barrel 10 is restricted.

  At this time, the operating body 40 is positioned at a position Z behind the predetermined position X. Therefore, the operating body 40 is not moved to the predetermined position X of the barrel 10 by pushing the pressing operation portion 18 forward with respect to the barrel 10, so switching of the lead-out unit 20 from the non-writing state to the writing state is performed. I can not do it.

  In addition, even if the pressing operation unit 18 is pushed forward with respect to the shaft cylinder 10 when the lead delivery unit 20 is in the writing state, only the writing lead 21 is sent forward from the chuck unit 28 and the lead delivery unit 20 is It can not be switched to the unwritten state. This is because the operating body 40 can not be moved to the predetermined position X by pushing the pressing operation unit 18 forward with respect to the barrel 10 as described above.

  Next, the operation of the mechanical pencil 100 when writing will be described. 6A is a schematic longitudinal sectional view showing a front portion of the mechanical pencil 100 of FIG. 1 when a strong writing pressure is not applied to the writing core 21, and FIG. 6B is a schematic drawing showing a strong writing pressure is applied to the writing core 21. 2 is a schematic longitudinal sectional view showing the front portion of the mechanical pencil 100 of FIG. As shown in FIG. 6A, at the time of writing, the barrel 10 is generally held so that the axial direction da forms an acute angle with the paper surface P. Therefore, at the time of writing, a force including a component perpendicular to the axial direction da of the barrel 10 (a component in the radial direction of the barrel 10) and a component of the axial direction da act on the writing core 21. When strong writing pressure is applied to the writing core 21 at the time of writing, the mechanical pencil 100 of the present embodiment respectively has a component perpendicular to the axial direction da of the writing pressure and a component of the axial direction da as follows. It absorbs and reduces breakage of the writing core 21 protruding from the base 30.

  That is, when a strong writing pressure acts on the writing core 21, the taper portion 22 t of the holding member 22 and the pressing portion 15 of the shaft cylinder 10 with the writing core 21 and the die 30 by the component of the writing pressure perpendicular to the axial direction da. A strong pressing force acts in the period. Then, the tapered portion 22t of the holding member 22 is tapered toward the front, so that as shown in FIG. 6B, the lead-out unit 20 is biased toward the axis L while the front is tilted with respect to the axis L. And moves backward relative to the barrel 10 while compressing the

By the way, the base 30 is urged forward to the lead-out unit 20 by the base spring 33. Due to this biasing force, the mouthpiece 30 moves forward relative to the core feeding unit 20 in accordance with the amount of relative movement of the core feeding unit 20 rearward relative to the barrel 10. That is, even if the lead-out unit 20 moves relative to the barrel 10 relative to the barrel 10, the mouthpiece 30 does not move relative to the barrel 10 in the axial direction da. As a result, the length of the writing core 21 protruding from the front end of the mouthpiece 30 decreases.

  At the same time, the writing core 21 is pushed rearward by the component of the axial direction da of the writing pressure. When the component in the axial direction da of the writing pressure exceeds the biasing force of the biasing means 60, the lead-out unit 20 moves relative to the barrel 10 rearward while compressing the biasing means 60 further. That is, the length of the writing core 21 protruding from the front end of the mouthpiece 30 is further reduced, and breakage of the writing core 21 is more effectively avoided.

  Then, the writing pressure applied to the writing core 21 is weakened, and the core feeding unit 20 is pushed back toward the barrel 10 by the biasing force of the biasing means 60. Thereby, the state shown in FIG. 6A is restored.

  When writing is completed, the lead-out unit 20 is put into the non-writing state as follows, and the base 30 is inserted into the barrel 10. That is, the control lever 41 is pushed forward with respect to the barrel 10. Thus, the slide cam 42 and the movable body 50 coupled to the operation lever 41 move forward relative to the barrel 10 while compressing the coil spring 61. The relative movement causes the outer ribs 72 of the cam follower 70 to move forward from the gap 12g between the inner ribs 12r. As a result, the cam follower 70 is allowed to rotate relative to the barrel 10 about its axis L again. When the outer ribs 72 move forward from the gap 12g between the inner ribs 12r, the cam follower 70 is relatively rotated about the axis L of the barrel 10 by the cam side pressing portion 42p of the slide cam 42, and the axis L The phase of the outer rib 72 and the phase of the gap 12g between the inner ribs 12r coincide with each other.

  Then, the pressing force applied to the operating lever 41 is weakened, and the moving body 50, the cam follower 70 and the operating body 40 are moved relative to the shaft cylinder 10 rearward by the biasing force of the biasing means 60 and the coil spring 61. Start. At this time, since the outer ribs 72 of the cam follower 70 can enter into the gap 12g between the inner ribs 12r, the cam follower 70 and the movable body 50 can move relative to the barrel 10 until the lead-out unit 20 is not written. Relative movement backward is permitted. As a result, the operation for placing the lead-out unit 20 in the writing state is performed in the reverse order, and the initial state (see FIG. 2) in which the base 30 is sunk into the barrel 10 is restored.

  When the base 30 is inserted into the barrel 10, the base spring 33 is gradually extended to move the base 30 relative to the chuck unit 28 in the forward direction. Therefore, even if the writing core 21 protrudes to a certain extent from the front end of the mouthpiece 30 when writing is finished, at least a part of the protruding portion of the writing core 21 is embedded in the mouthpiece 30 by this relative movement. Ru. By this, when the lead-out unit 20 is in the non-writing state, the writing core 21 is surely protected. Then, when the mouthpiece 30 is exposed again from the front end of the barrel 10, as described above, the mouthpiece 30 is moved relative to the chuck unit 28 backward, so the front end of the writing core 21 protrudes again, and the pressing operation is performed. Writing can be resumed without the pressing operation of the portion 18 or the swinging operation by the weight body 90.

  Furthermore, in the mechanical pencil 100 according to the present embodiment, when the base 30 is inserted into the barrel 10, the extension of the writing core 21 is restricted. That is, as described above, in the mechanical pencil 100, when the lead-out unit 20 is in the non-writing state, the contact portion 29p of the chuck unit 28 is in contact with the bulging portion 52 of the movable body 50 from the rear. Therefore, when the pressing operation unit 18 is moved forward relative to the barrel 10 or when the inertia force of the weight 90 is applied to the connector 29, the moving unit 50 together with the chuck unit 28 moves forward relative to the barrel 10. Move relative to each other. At this time, the biasing means 60 and the chuck support unit 27 are also moved forward relative to the barrel 10 with the moving body 50. That is, the chuck unit 28 and the chuck support unit 27 simultaneously move relative to the barrel 10 in the forward direction. After all, when the lead-out unit 20 is in the non-writing state, the relative movement forward of the chuck unit 28 with respect to the chuck support unit 27 is restricted. Even if the operation is performed, the writing core 21 is not drawn out.

  According to the present embodiment as described above, when the core feeding unit 20 presses the pressing operation unit 18 forward in the non-writing state, the barrel 40 at the position Z behind the predetermined position X of the operating body 40 Relative movement to the front is restricted. For this reason, when the pressing operation unit 18 is pushed in, the operating body 40 is pushed to the predetermined position X undesirably and the erroneous operation that the lead unit 20 switches from the writing state to the non-writing state can be avoided. A mechanical pencil 100 of the formula may be provided. Furthermore, since the said erroneous operation is prevented, when pushing in the operation body 40 to the predetermined position X, it is not necessary to comprise so that a big force may be required. That is, according to the present embodiment, it is possible to provide a retractable mechanical pencil 100 in which the cap 30 can be operated with a light force.

  Further, in the present embodiment, the operation body 40 presses the chuck support unit 27 from the rear, and the pressing operation unit 18 presses the chuck unit 28 from the rear. In particular, the operating body 40 of the present embodiment is configured to press the chuck support unit 27 from the rear via the cam follower 70, the moving body 50, and the biasing means 60. That is, since the press operation unit 18 and the operation body 40 press different constituent members, the mouthpiece 30 is not protruded or retracted from the front end of the barrel 10 by pushing the press operation unit 18. By this, it is possible to reliably realize a configuration for avoiding an erroneous operation when the base 30 is made to appear and retract from the barrel 10 in the retractable mechanical pencil 100.

  Furthermore, the distance between the position Y of the operating body 40 and the predetermined position X when the lead-out unit 20 is in the non-writing state is a distance that allows the chuck support unit 27 to move forward relative to the barrel 10; The sum of the distance with which the chuck unit 28 can move relatively forward with respect to the unit 27 is larger than the sum. In other words, the abutted portion 12a that determines the predetermined position X is positioned so as to satisfy the relationship between the distances described above. By this, it is possible to easily realize a configuration for avoiding an erroneous operation when the base 30 is made to protrude and retract from the barrel 10 in the retractable mechanical pencil 100.

  By the way, when a strong writing pressure is applied to the writing core, the present applicant slides the base in the radial direction of the shaft cylinder with respect to the shaft cylinder, and the writing core slides backward with respect to the base. We developed a mechanical pencil and filed it as International Application PCT / JP2016 / 068863. In this mechanical pencil, when the shaft cylinder presses the core feeding unit, the core feeding unit moves relative to the shaft cylinder rearward. By this, in addition to the axial component of the writing pressure, the radial component of the writing pressure is also absorbed, so that breakage of the writing core is effectively reduced. In order to realize such a mechanism with a retractable mechanical pencil, when the lead-out unit is in the writing state, it is necessary that the lead-out unit and the shaft cylinder are in contact with each other.

  The mechanical pencil 100 according to the present embodiment responds to such a request. That is, the mechanical pencil 100 has the base spring 33 which is an elastic body disposed in a compressed state between the lead-out unit 20 and the base 30, and when the lead-out unit 20 is in the writing state, the base 30 The barrel-side reduced diameter portion 16 of the barrel 10 is pressed from the rear. For this reason, even if the lead-out unit 20 including the writing core 21 is moved relative to the barrel 10 rearward by the writing pressure, the mouthpiece 30 does not move relative to the barrel 10 in the axial direction da. Thereby, when strong writing pressure acts on the writing core 21, the length of the writing core 21 protruding from the front end of the die 30 is reduced, and breakage of the writing core 21 can be effectively reduced.

  The mechanical pencil 100 causes the barrel 10 to move the core feeding unit 20 relative to the barrel 10 rearward with the radial component of the barrel 10 of the writing pressure. For this reason, according to the present embodiment, the length of the writing core 21 protruding from the front end of the mouthpiece 30 is also reduced by the radial direction component of the barrel 10 of the writing pressure, and breakage of the writing core 21 is more effective. It can be reduced.

  Furthermore, when the lead-out unit 20 of the mechanical pencil 100 is in the non-writing state, relative movement of the chuck unit 28 in the axial direction da with respect to the chuck support unit 27 by the inertia force of the weight 90 is restricted. . This is realized by the contact between the bulging portion 52 of the movable body 50 and the contact portion 29p of the chuck unit 28 when the lead-out unit 20 is in the non-writing state. That is, according to the present embodiment, if the base 30 is inserted into the barrel 10, the writing core 21 is extended even if, for example, the inertial force of the weight body 90 acts on the chuck unit 28 when carrying it. There is nothing to be done. Thereby, a highly convenient mechanical pencil 100 can be provided.

Reference Signs List 10 shaft cylinder 11 front cylinder 12 rear cylinder 12a abutted portion 12b cam follower restricting portion 12c operation body restricting portion 12g gap 12r inner rib 13 first receiving portion 15 pressing portion 16 shaft tube side reduced diameter portion 18 pressing operation portion 18h holder portion Reference Signs List 20 core feeding unit 21 writing core 22 holding member 22 f drawn part 22 t tapered part 23 core pipe 24 chuck 25 ring 26 return spring 27 chuck support unit 27 a second receiving part 27 p outer cylinder 27 s reduced diameter part 28 chuck unit 29 connector 29 p contact Part 30 base 30a opening 31 guide pipe 32 sleeve part 32c small diameter part 32d enlarged diameter part 33 base spring 40 operation body 41 operation lever 41c clip part 41e engagement hole 41m operation lever main body 42 slide cam 42e projection 42m valley part 42p cam Side pressing part 42u raised part 50 Moving body 51 flange portion 52 bulging portion 52 d small diameter portion 60 biasing means 61 coil spring 70 cam follower 71 cam follower main body 72 outer rib 72 p pressed portion 80 rubber 81 knob 90 weight body 100 mechanical pencil

Claims (6)

With a cylinder,
An operating body exposed from the barrel and movable relative to the barrel in the axial direction;
A pressing operation unit held by the operating body so as to be movable relative to the operating body in the axial direction;
And a core feeding unit supported in the cylinder so as to be relatively movable in the axial direction of the cylinder and holding a writing core,
When the operating body is pushed forward to a predetermined position with respect to the shaft cylinder, the core feeding unit is alternately held by the shaft cylinder in a relatively forward writing state and a relatively backward non-writing state,
When the pressing operation unit is pushed forward with respect to the barrel, the writing core is fed forward from the core feeding unit,
A mechanical pencil whose forward relative movement with respect to the barrel is restricted at a position rearward of the predetermined position when the pressing operation unit is pressed forward in the non-writing state. The core feeding unit is
A chuck support unit movable relative to the shaft cylinder in the axial direction;
A chuck unit supported by the chuck support unit so as to be relatively movable in the axial direction with respect to the chuck support unit, and holding the writing core so as to be able to be fed forward;
The operating body presses the chuck support unit from the rear,
The mechanical pencil according to claim 1, wherein the pressing operation unit presses the chuck unit from behind. The operating body is a slide cam that moves relative to the shaft cylinder in the axial direction;
A cam follower, disposed inside the barrel, movable relative to the barrel in the axial direction and rotatable around the axis;
A movable body disposed in front of the cam follower inside the barrel and movable relative to the barrel in the axial direction;
And a biasing means for biasing the chuck support unit forward with respect to the movable body,
The mechanical pencil according to claim 2, wherein the operating body presses the chuck support unit from the rear via the cam follower, the movable body, and the biasing means.   The distance between the position of the operating body and the predetermined position when the lead-out unit is in the non-writing state is the distance that the chuck support unit can move forward relative to the shaft cylinder, and the chuck support unit The mechanical pencil according to claim 2 or 3, wherein the sum of the distance by which the chuck unit can move forward relatively is larger. A base supported in front of the core feeding unit and having an opening through which the writing core held by the core feeding unit can pass;
And an elastic body disposed in a compressed state between the lead-out unit and the mouthpiece,
The mechanical pencil according to any one of claims 1 to 4, wherein when the lead-out unit is in the writing state, the base presses the barrel from behind.   The mechanical pencil according to claim 5, wherein the axial cylinder causes the core delivery unit to move rearward relative to the axial cylinder by a radial component of the axial cylinder of the writing pressure.