JP2019119111A - mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a haunting mechanical pencil having both a good writing feeling and convenience. A mechanical pencil 100 includes a shaft cylinder 10, a core feeding unit 20 for holding a writing core 21, a heavy body 90 for feeding a writing core 21 by an inertial force, and at least a part of the shaft cylinder 10. It is provided with an operating body 40 exposed to the outside of the above. By moving the operating body 40 forward relative to the shaft cylinder 10, the core feeding unit 20 is positioned relatively forward with respect to the shaft cylinder 10 and in a writing state relatively rearward with respect to the shaft cylinder 10. It can be switched alternately between the non-written state, which is positioned. The core feeding unit 20 presses the barrel 10 from the rear when it is in the writing state, and when the core feeding unit 20 is in the non-writing state, the feeding of the writing core 21 by the heavy body 90 is restricted. [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 writing state in which a base attached to the front end of the lead-out unit for holding a writing core protrudes from the front end of the barrel by pushing the operating body projecting rearward from the rear end of the barrel into the front with respect to the barrel In addition, there is known a mechanical pencil that can be alternately switched to a non-writing state in which the base is immersed in the barrel. Such an appearance type retractable mechanical pencil is described, for example, in Patent Document 1 below.

  In a retractable mechanical pencil, usually, when the lead-out unit is in the writing state, the front end of the lead-out unit is slightly separated from the barrel. Although a cam mechanism is employed to switch the state (whether writing or non-writing) of the lead-out unit, it is associated with the barrel just before the end of the switching operation from the non-writing to the writing. This is because the cam follower associated with the core feeding unit needs to be slightly dropped toward the rear of the barrel with respect to the cam. However, when the front end of the core feeding unit is slightly separated from the barrel, the front end of the core feeding unit may be shaken with respect to the barrel due to the writing pressure, and the writing feeling may be impaired.

  There is also known a swing-type mechanical pencil in which a weight is disposed inside the barrel so as to be movable relative to the barrel in the axial direction, and the writing core is drawn out by the inertia force of the weight. By configuring the above-mentioned up and down type mechanical pencil as the swing-out type mechanical pencil, it is possible to provide a mechanical pencil having better operability. In this case, when the lead-out unit is in the non-writing state, for example, the weight body vibrates due to vibration at the time of movement, and the writing core may be drawn out undesirably due to the inertial force.

JP, 2017-159579, A

  The present invention has been made in view of the above situation. That is, the object of the present invention is to prevent the core feeding unit from being shaken by the pen pressure to the barrel of the core feeding unit, and to limit the extension of the writing core due to the inertia force of the weight when the core feeding unit is in the non-writing state. An object of the present invention is to provide an appearance type pencil having a good writing feeling and convenience.

The mechanical pencil according to the present invention comprises:
A core feeding unit disposed inside the barrel so as to be movable relative to the barrel in the axial direction of the barrel and holding a writing core;
A weight body disposed inside the barrel so as to be movable relative to the core feeding unit in the axial direction, and performing a feeding operation for feeding the writing core by an inertia force;
An operating body supported by the shaft cylinder so as to be movable relative to the shaft cylinder in the axial direction, and at least a part of which is exposed to the outside of the shaft cylinder;
When the operating body is moved relative to the shaft cylinder in the forward direction, the lead-out unit is in a writing state positioned forward with respect to the shaft cylinder, and backward with respect to the shaft cylinder. It can be switched alternately to the non-writing state to be positioned,
When the core feeding unit is in the writing state, the core feeding unit presses the shaft cylinder from the rear,
When the lead-out unit is in the non-writing state, the extension of the writing core by the weight body is limited.

The above-mentioned mechanical pencil is disposed inside the cylinder, and moves relative to the cylinder relative to the cylinder relative to the cylinder relative to the cylinder relative to the cylinder relative to the cylinder,
And a biasing means for biasing the core feeding unit forward with respect to the movable body,
When the core feeding unit is in the writing state, the core cylinder may be pressed from behind by the biasing force of the biasing unit.

The core feeding unit is
A chuck support unit biased forward with respect to the movable body by the biasing means;
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;
When the core feeding unit is in the non-writing state, relative movement of the chuck unit in the axial direction with respect to the chuck support unit due to an inertial force of the weight body may be restricted.

The movable body has a substantially cylindrical shape and has a bulging portion on the inner surface,
The chuck unit has an abutting portion that abuts on the bulging portion of the movable body from behind.
The bulging portion and the contact portion may be separated from each other when the core feeding unit is in the writing state, and may be in contact with each other when the core feeding unit is in the non-writing state.

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.
It further comprises an elastic body disposed in a compressed state between the core feeding unit and the mouthpiece,
When the lead-out unit is in a writing state, the base may press the barrel from behind.

  Further, the shaft cylinder may move the lead-out unit relative to the shaft cylinder with respect to the shaft cylinder by a radial component of the cylinder pressure of the writing pressure.

  According to the present invention, it is possible to prevent the core feeding unit from being wobbled by the pen pressure with respect to the barrel of the core and further to limit the extension of the writing core by the inertia force of the weight when the core feeding unit is in the non-writing state. It is possible to provide an appearance-type mechanical pencil that achieves both writing feeling and convenience.

  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. 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.

  Therefore, when the core feeding unit is in the writing state, if the core feeding unit can be prevented from shaking due to the writing pressure by bringing the core feeding unit into contact with the shaft cylinder, international application PCT / JP2016 The mechanical pencil described in U.S. Pat.

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 includes a barrel 10, a lead-out unit 20 disposed inside the barrel 10 and holding the writing core 21, and a inertia force disposed inside the barrel 10. And a weight body 90 for performing a feeding operation for feeding the writing core 21. The core feeding unit 20 is disposed so as to be movable relative to the barrel 10 in the axial direction da. Also, the weight body 90 is disposed so as to be movable relative to the core feeding unit 20 in the axial direction da.

  The mechanical pencil 100 is further supported by the barrel 10 so as to be movable relative to the barrel 10 in the axial direction da, and further includes an operating body 40 at least a part of which is exposed to the outside of the barrel 10. The specific configuration of the operating body 40 will be described later. When the operation body 40 is moved relative to the barrel 10 in a forward direction (pushed in), the core feeding unit 20 is in a writing state (see FIG. 1) positioned relative to the barrel 10 relative to the front; It switches alternately to the non-writing state (refer FIG. 2) positioned back relatively with respect to the axial cylinder 10. FIG. This 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. In addition, the slide cam 42 has, at its rear end, a plurality of pressing portions 42p that press pressed portions 72p of a cam follower 70 described later. The pressing portion 42p is formed as a projecting lower projection forward, and a valley 42m recessed rearward is formed between the adjacent pressing portions 42p. The phase around the axis L of the 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 portion 42m and the phase of the abutted portion 12a The phase around the axis L 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 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.

  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. As shown in FIG. 1 and FIG. 2, the chuck unit 28 has an abutting portion 29p which is disposed through the inside of the moving body 50 and the cam follower 70 and abuts on the bulging portion 52 of the moving body 50 from behind. There is. 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, the bulging portion and the contact portion are in contact. The contact portion is in contact with the contact portion. The chuck unit 28 is restricted from moving relative to the chuck support unit 27 in the axial direction da by the inertial force of the weight body 90 in the non-writing state. The details will be described later.

  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.

  Furthermore, the core feeding unit 20 further includes a pressing operation unit 18 which is held by the operation lever 41 of the operating body 40 and presses the core pipe 23 forward with respect to the chuck supporting unit 27. The writing core 21 is drawn out from the chuck unit 28 by pressing the pressing operation unit 18 forward (knocking operation). A specific aspect of the feeding of the writing core 21 will be described later. Furthermore, the pressing operation portion 18 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 about the axis L by the force with which the 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).

  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 followers 70 are relatively rotated about the axis L of the barrel 10 by the pressing portions 42p of the slide cam 42, and the outer ribs of the cam followers 70 with respect to the axis L The phase of 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.

  In the mechanical pencil 100 according to the present embodiment, the extension of the writing core 21 is restricted when the base 30 is inserted into the barrel 10. 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, the core feeding unit 20 presses the pressing portion 15 of the barrel 10 from the rear when in the writing state. Wobble can be prevented. Furthermore, when the lead-out unit 20 is in the non-writing state, the extension of the writing core 21 by the inertial force of the weight body 90 is limited. That is, according to the present embodiment, it is possible to provide an ups and downs type mechanical pencil 100 which has both good writing feeling and convenience.

  Specifically, the mechanical pencil 100 is disposed inside the barrel 10, and moves with the moving body 50 that moves relative to the barrel 10 relative to the barrel 10 by the relative movement of the operating body 40 forward with respect to the barrel 10; And a biasing means 60 for biasing the lead unit 20 forward with respect to the body 50. When the core feeding unit 20 is in the writing state, the biasing force of the biasing unit 60 presses the barrel 10 from the rear. For this reason, when the lead-out unit 20 is in the writing state, the pressing portion 15 of the barrel 10 can be reliably pressed forward.

  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 is restricted by the inertial force of the weight 90. 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.

  The mechanical pencil 100 described above 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.

  In the above description, the pressing operation unit 18 for pressing the chuck unit 28 is provided in the operating body 40, but the present invention is not limited to such a form. For example, the pressing operation unit 18 may be directly attached to the core pipe 23.

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 20 core feeding unit 21 writing core 22 holding member 22 f drawn part 22 t tapered part 23 core pipe 24 chuck 25 clamping ring 26 return spring 27 chuck supporting unit 27 a second receiving part 27 p outer cylinder 27 s reduced diameter part 28 chuck unit 29 connector 29 p Contact portion 30 mouthpiece 30a opening 31 guide pipe 32 sleeve portion 32c small diameter portion 32d enlarged diameter portion 33 mouthpiece spring 40 operation body 41 operation lever 41c clip portion 41e engagement hole 41m operation lever main body 42 slide cam 42e protrusion 42m valley portion 42p Pressed part 42u raised part 50 Body 51 flange 52 bulging portion 52d smaller diameter portion 60 biasing means 61 the coil spring 70 the cam follower 71 the cam follower body 72 outer ribs 72p pressed portion 80 rubber 81 knob 90 weight body 100 Pencil

Claims (6)

With a cylinder,
A core feeding unit disposed inside the barrel so as to be movable relative to the barrel in the axial direction of the barrel and holding a writing core;
A weight body disposed inside the barrel so as to be movable relative to the core feeding unit in the axial direction, and performing a feeding operation for feeding the writing core by an inertia force;
An operating body supported by the shaft cylinder so as to be movable relative to the shaft cylinder in the axial direction, and at least a part of which is exposed to the outside of the shaft cylinder;
When the operating body is moved relative to the shaft cylinder in the forward direction, the lead-out unit is in a writing state positioned forward with respect to the shaft cylinder, and backward with respect to the shaft cylinder. It can be switched alternately to the non-writing state to be positioned,
When the core feeding unit is in the writing state, the core feeding unit presses the shaft cylinder from the rear,
A mechanical pencil, wherein the unwinding of the writing core by the weight body is restricted when the core feeding unit is in the non-writing state. A movable body disposed inside the barrel and moving forward relative to the barrel by relative movement of the operating body to the barrel relative to the barrel;
And a biasing means for biasing the core feeding unit forward with respect to the movable body,
The mechanical pencil according to claim 1, wherein the core feeding unit pushes the shaft cylinder forward by the biasing force of the biasing unit when in the writing state. The core feeding unit is
A chuck support unit biased forward with respect to the movable body by the biasing means;
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 mechanical pencil according to claim 2, wherein when the lead-out unit is in the non-writing state, the chuck unit is restricted in relative movement in the axial direction with respect to the chuck support unit by inertial force of the weight body. . The movable body has a substantially cylindrical shape and has a bulging portion on the inner surface,
The chuck unit has an abutting portion that abuts on the bulging portion of the movable body from behind.
The mechanical pencil according to claim 3, wherein the bulging portion and the abutting portion are separated from each other when the lead-out unit is in the writing state, and are in contact with each other when the lead-out unit is in the non-writing state. . 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;
It further comprises an elastic body disposed in a compressed state between the core feeding 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 die presses the barrel forward.   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.