JP5750315B2 - Swing-out mechanical pencil - Google Patents

Description

  The present invention relates to a swing-out type mechanical pencil that draws out a core by utilizing an inertial force of a weight body generated by shaking.

  Conventionally, a mechanical pencil that winds a core using the inertial force of a weight body that is formed by winding a wire in a coil shape to make the front and rear portions elastic as coil spring portions and shaking the weight body. Are known. (See Patent Document 1)

  However, in the mechanical pencil, when the weight body slides, when the front and rear coil spring portions come into contact with the inner surface of the shaft tube, the coil spring portion is bent and the frictional resistance is increased and the sliding becomes difficult. There was a problem that contact sound was generated. Therefore, conventionally, it has been necessary to increase the clearance between the outer surface of the weight body and the inner surface of the shaft cylinder with a margin.

Japanese Utility Model Publication No. 63-23181

  The problem to be solved is that when the gap between the outer surface of the weight body and the inner surface of the shaft tube is increased, the outer diameter of the shaft tube becomes thicker.

  The present invention is a swing-out mechanical pencil that slidably installs a weight body between a core tank for storing a spare core and a shaft cylinder, and advances the chuck by the inertial force of the weight body generated by shaking. The wire is wound in a coil shape to form a weight body, the coil spring portion is formed in the front portion and the rear portion of the weight body, and the wire is closely attached in a coil shape between the front portion and the rear portion. A narrow diameter portion is formed, the inner diameter of the narrow diameter portion is configured to be smaller than the inner diameters of the front portion and the rear portion, and the weight body is further narrowed by a gap between the inner surface of the shaft cylinder and the front portion of the weight body and the outer surface of the rear portion. The most important feature is that the gap between the inner surface of the diameter portion and the outer surface of the core tank is narrower.

  The present invention has a smaller inner diameter than the inner diameter of the front part and the rear part having a coil spring part, and the weight body from the gap between the inner surface of the shaft cylinder and the outer surface of the front and rear parts of the weight body. Since the gap between the inner surface of the narrow diameter portion and the outer surface of the core tank is narrower, there is no risk that the front and rear portions of the weight body come into contact with the inner surface of the shaft cylinder and the outer surface of the core tank. The advantage that the sliding can be surely performed and the contact sound between the weight body and the shaft tube is not generated is obtained.

FIG. 1 is a cross-sectional view showing a swing-out mechanical pencil according to a first embodiment of the present invention. Example 1 FIG. 2 is an enlarged cross-sectional view showing the weight body of FIG. Example 1 FIG. 3 is an enlarged cross-sectional view taken along line AA of FIG. Example 1 4 is an enlarged sectional view taken along line BB in FIG. Example 1 FIG. 5 is an enlarged sectional view taken along line CC of FIG. Example 1 FIG. 6 is a cross-sectional view showing a swing-out mechanical pencil according to a second embodiment of the present invention. (Example 2)

  In the present invention, a wire is closely attached in a coil shape between a front portion and a rear portion to form a small diameter portion, an inner diameter of the small diameter portion is made smaller than inner diameters of the front portion and the rear portion, and an inner surface of the shaft tube The gap between the inner surface of the small-diameter portion of the weight body and the outer surface of the core tank is configured to be narrower than the gap between the outer surface of the front portion and the rear portion of the weight body, and the weight body is reliably slid and A swing-out mechanical pencil that reduces the contact noise of the shaft cylinder has been realized.

  Hereinafter, based on FIG.1, FIG.2, FIG.3, FIG.4 and FIG. 5, the swing-out type mechanical pencil of Example 1 in this invention is demonstrated. Moreover, let the left side of FIG. 1 be the front, and let the right side be back. First, a connector 2 made of a synthetic resin pipe is press-fitted and fixed to the rear part of the metal chuck 1. A front portion of a synthetic resin core tank 4 containing a spare core 3 is press-fitted and fixed to the rear portion 2A of the connector 2. A fastener 5 is externally fitted to the head 1A of the chuck 1, and a spring 7 is attached between the connector 6 and the connector 2 for receiving the fastener 5 with a load of 200 g or less. Configure.

  A front hole 8A of the front shaft 8 is configured so that the core tank 4 and the connector 2 of the mechanism portion can be inserted, and the front member 8 is detachably screwed to the front end of the front shaft 8 and the front portion of the front shaft 8. The connector 6 is held by the inner stage 9A. The tip member 9 contains a lead holder 10 made of an elastic body such as rubber that holds the lead 3 with an appropriate force. A grip 11 made of a soft rubber material is attached to the front narrow diameter portion 8B of the front shaft 8. Further, the front shaft 8 is formed with an inner hole 8C having a diameter larger than that of the front hole 8A, and a rear hole 8D that is opened from the rear end and has a diameter larger than that of the inner hole 8C. Further, a locking window 8E is formed at the rear portion of the front shaft 8, and a concave groove 8F extending forward in the longitudinal direction from the rear end is formed at a position facing the locking window 8E.

  Further, as shown in FIG. 2, the weight body 12 is formed in a cylindrical shape by winding a metal wire, and a coil spring portion 12 </ b> B is formed on the front portion 12 </ b> A of the weight body 12 and the rear portion of the weight body 12. A coil spring portion 12D is formed on 12C. Between the front portion 12A and the rear portion 12C, a wire is closely attached in a coil shape to form the small diameter portion 12E, and the inner diameter of the small diameter portion 12E is smaller than the inner diameters of the front portion 12A and the rear portion 12C. The weight body 12 is disposed between the inner hole 8C of the front shaft 8 and the core tank 4 so as to be slidable in the longitudinal direction. Further, the gap between the inner surface of the small diameter portion 12E of the weight body 12 and the outer surface of the core tank 4 is narrower than the gap between the inner surface of the inner hole 8C of the front shaft 8 and the outer surface of the front portion 12A and the rear portion 12C of the weight body 12. To do. Furthermore, the longitudinal dimension of the front part 12A and the rear part 12C of the weight body 12 is configured to be longer than the longitudinal dimension of the rear part 2A of the connector 2.

  Furthermore, the rear shaft 13 is integrally formed with a clip 14 on the upper side, and a small-diameter portion 13A is formed on the front portion. Protrusions 13B are formed on the outer peripheral surface of the small-diameter portion 13A so as to be located immediately below the clip 14, and open windows 13C extending in the longitudinal direction are formed on both sides of the small-diameter portion 13A so as to face each other. The small-diameter portion 13A where 13B is located is configured to be appropriately elastically deformable. The rear shaft 13 is formed with an inner flange 13D for preventing the core tank 4 from sideways on the inner side of the front part, and a step part 13E for contacting the return spring 15 is formed on the inner side of the rear part. . Further, a key groove 13F is formed above and below the rear hole of the rear shaft 13 so as to face the opening window 13C at a position shifted by 90 degrees with respect to the axial center.

  Furthermore, a protrusion 16B is formed on the outer peripheral surface of the front cylinder 16A of the pressing member 16, and an opening window 16C is formed on the top and bottom of the front cylinder 16A so as to face each other, and the front cylinder 16A in which the protrusion 16B is located. Is configured to be elastically deformable. An outer flange portion 16D is formed at the rear portion of the pressing member 16, and keys 16E that protrude outwardly are formed above and below the outer flange portion 16D at positions shifted by 90 degrees with respect to the projection 16B. Is done. Further, an inner flange 16F having a core insertion hole is formed on the inner surface of the pressing member 16, and the front surface of the inner flange 16F serves as a pressing surface that presses the rear end of the core tank 4.

  After the return spring 15 is externally fitted to the front portion of the pressing member 16, the pressing member 16 is inserted from the rear of the rear shaft 13 with the key 16E of the pressing member 16 aligned with the key groove 13F of the rear shaft 13, and the pressing member 16 is inserted. The protrusion 16B is loosely fitted in the opening window 13C of the rear shaft 13 so as to be slidable in the longitudinal direction. Moreover, since the return spring 15 is mounted between the step portion 13E of the rear shaft 13 and the outer flange portion 16D of the pressing member 16 with a load at the time of mounting of about 350 g, the normal pressing member 16 is normally urged rearward in the longitudinal direction. Yes. Moreover, the rear portion of the lead tank 4 is inserted into the front inner hole 16G of the pressing member 16, and the rear end of the lead tank 4 and the pressing surface of the pressing member 16 are appropriately separated. Further, an eraser 17 is fitted and attached to the rear inner hole 16H of the pressing member 16, and a knob 18 covering the eraser 17 is fitted to the rear outer surface 16I of the pressing member 16.

  The rear shaft 13 assembled in this way is inserted from the rear end of the front shaft 8, and the rear shaft 13 is advanced by aligning the raised portion 13G of the rear shaft 13 with the concave groove 8F of the front shaft 8. The protrusion 13B is fitted into the locking window 8E of the front shaft 8, and the rear shaft 13 is attached to the front shaft 8. The front shaft 8 and the rear shaft 13 constitute a shaft cylinder. Moreover, the locking window 8E of the front shaft 8 and the protrusion 13B of the rear shaft 13 are hidden by the clip 14, so that the appearance is not impaired. The rear portion of the core tank 4 is inserted into the inner flange 13D of the rear shaft 13, and the weight body 12 is restricted from sliding in the longitudinal direction by the outer flange 2B of the connector 2 and the inner flange 13D of the rear shaft 13. Is done.

  The swing-out mechanical pencil described above compresses the spring 7 by the inertia force of the weight body 12 generated by swinging the shaft cylinder composed of the front shaft 8 and the rear shaft 13 to advance the chuck 1 and feed the core 3. At this time, the gap between the inner surface of the small diameter portion 12E of the weight body 12 and the outer surface of the core tank 4 is narrower than the gap between the inner surface of the inner hole 8C of the front shaft 8 and the outer surface of the front portion 12A and the outer surface of the rear portion 12C. Thus, when the weight body 12 slides in the longitudinal direction, the inner surface of the small diameter portion 12E of the weight body 12 and the outer surface of the core tank 4 come into contact with each other, but the inner surface of the front portion 12A or the rear portion 12C of the weight body 12 And the outer surface of the core tank 4 or the outer surface of the front portion 12A of the weight body 12 or the outer surface of the rear portion 12C and the inner surface of the inner hole 8C of the front shaft 8 are not in contact. There is no concern that stress is applied to the coil spring portion 12D formed on the portion 12B or the rear portion 12C of the weight body 12. Therefore, the weight body 12 can be reliably slid in the longitudinal direction. In addition, the rear part 2A of the connector 2 is press-fitted into the front part of the core tank 4 by configuring the longitudinal dimension of the front part 12A and the rear part 12C having a slightly larger diameter of the weight body 12 to be longer than the longitudinal dimension of the rear part 2A of the connector 2. Even if the front part of the lead tank 4 is slightly thickened after being fixed, there is no fear that the front part of the lead tank 4 contacts the inner surface of the front part 12A of the weight body 12. In addition, since the weight body 12 is formed in the same shape in the front and rear, no problem arises regardless of which direction the weight body 12 is attached during attachment.

  Hereinafter, the swing-out mechanical pencil according to the second embodiment of the present invention will be described with reference to FIG. In addition, the same member as FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits the description. First, the front shaft 108 is made of transparent or colored synthetic resin having transparency, and the front hole 108A of the front shaft 108 is configured to allow the core tank 4 and the connector 2 of the mechanism portion to be inserted. The mechanism portion is inserted through the front hole 108A of the front shaft 108, and the connecting tool 6 is held by the inner end 9A of the tip member 9 screwed into the front end of the front shaft 108 and the front portion of the front shaft 108.

  The front shaft 108 is formed with a rear hole 108D that is opened from the rear end and has a diameter larger than that of the front hole 108A, and a locking window 108E is formed at the rear portion of the front shaft 108. Further, a concave groove 108F extending forward in the longitudinal direction from the rear end is formed at a position facing the locking window 108E of the front shaft 108. The weight body 12 is slidably incorporated in the rear hole 108D of the front shaft 108, and the core tank 4 is inserted into the through hole of the weight body 12. The rear shaft 113 is made of a colored opaque synthetic resin, integrally formed with a clip 114 on the upper rear portion, and a small diameter portion that extends forward from the large diameter rear portion and is inserted into the front shaft 108 from the rear. The length in the longitudinal direction of 113A is configured to be more than half of the total length of the front shaft 108, preferably about 80%. A protrusion 113B is formed on the outer peripheral surface of the rear portion of the small-diameter portion 113A so as to be positioned immediately below the clip 114. Further, opening windows extending in the longitudinal direction are formed on both sides of the small-diameter portion 113A so as to face each other, and the small-diameter portion 113A where the projection 113B is located is configured to be appropriately elastically deformable. Further, a raised portion 113G that is located on the opposite side of the projection 113B and extends in the longitudinal direction is formed in the narrow-diameter portion 113A of the rear shaft 113. The rear shaft 113 is formed with an inner flange 113D for preventing the core tank 4 from sideways and a step 113E for abutting the return spring 15 inside the rear portion. Further, a key groove 113F is formed above and below the rear hole of the rear shaft 113 so as to face the opening window at a position shifted by 90 degrees with respect to the axial center. After this, a concave portion slightly recessed in the circumference of the small-diameter portion 113A of the shaft 113 is formed to extend in the longitudinal direction, and a display is provided in the concave portion by printing.

  The rear shaft 113 is inserted from the rear end of the front shaft 108, the raised portion 113G of the rear shaft 113 advances the rear shaft 113 in accordance with the concave groove 108F of the front shaft 108, and the protrusion 113B of the rear shaft 113 is moved to the front shaft 108. And the rear shaft 113 is attached to the front shaft 108. The front shaft 108 and the rear shaft 113 constitute a shaft cylinder. Note that the locking window 108E of the front shaft 108 and the protrusion 113B of the rear shaft 113 are hidden by the clip 114, so the appearance is not impaired. The rear portion of the core tank 4 is inserted into the inner flange 113D of the rear shaft 113, and the weight body 12 slides in the longitudinal direction between the outer flange 2A of the connector 2 and the inner flange 113D of the rear shaft 113. Configure as possible. Further, the gap between the narrow diameter portion 12E of the weight body 12 and the outer surface of the core tank 4 is narrower than the gap between the inner surface of the narrow diameter portion 113A of the rear shaft 113 and the outer surface of the front portion 12A and the rear portion 12C of the weight body 12. To do.

  The swing-out mechanical pencil described above compresses the spring 7 by the inertia force of the weight body 12 generated by swinging the shaft cylinder composed of the front shaft 108 and the rear shaft 113 to advance the chuck 1 and feed the core 3. At this time, the clearance between the inner surface of the small diameter portion 12E of the weight body 12 and the outer surface of the core tank 4 is larger than the clearance between the inner surface of the small diameter portion 113A of the rear shaft 113 and the outer surface of the front portion 12A and the rear portion 12C of the weight body 12. Since the weight body 12 slides in the longitudinal direction, the narrow diameter portion 12E inner surface of the weight body 12 and the outer surface of the core tank 4 are in contact with each other, but the front surface 12A inner surface or the rear portion 12C of the weight body 12 is in contact. There is no fear that the inner surface and the outer surface of the core tank 4 are in contact with each other, and the outer surface of the front portion 12A of the weight body 12 or the outer surface of the rear portion 12C and the inner surface of the small diameter portion 113A of the rear shaft 113 are not in contact. There is no concern that stress is applied to the coil spring portion 12B or the coil spring portion 12D formed on the rear portion 12C of the weight body 12. Therefore, the weight body 12 can be reliably slid in the longitudinal direction.

  Note that the present invention is not limited to the above-described embodiment, and the members such as the front shaft, the rear shaft, and the pressing member are illustrated as one member for simplification of explanation, but two members each. The above members may be integrated by screwing, press-fitting, or the like. Further, the connector and the core tank may be configured integrally, or the front shaft and the rear shaft may be configured integrally.

  The weight body in which the wire is wound in a coil shape and the coil spring portion is formed in the front and rear portions can be reliably slid in the longitudinal direction, and can be applied to a swing-out type mechanical pencil with less contact sound of the weight body.

DESCRIPTION OF SYMBOLS 1 Chuck 3 cores 4 core tank 12 Weight body 12A Front part of the weight body 12B Coil spring part of the weight body 12 12C Rear part of the weight body 12D Coil spring part of the weight body 12E Fine diameter part of the weight body 12

Claims (1)

  A swing-out type mechanical pencil that slidably installs a weight body between a core tank for storing a spare core and a shaft cylinder, and advances the chuck by the inertial force of the weight body generated by shaking. Is formed into a coiled body to form a weight body, a coil spring part is formed at the front and rear parts of the weight body, and a small diameter part in which a wire is closely attached in a coil shape between the front part and the rear part. And the inner diameter of the small-diameter portion of the weight body is defined by the gap between the inner surface of the shaft cylinder and the front outer surface and the rear outer surface of the weight body. The swing-out mechanical pencil is characterized in that the gap between the core and the outer surface of the lead tank is narrower.

Images