JP5535091B2 - Knock mechanical pencil - Google Patents

Description

  The present invention relates to a knock mechanical pencil that reduces the amount of the remaining core to be discharged.

  Conventionally, a core holder that holds the core with an appropriate force inside the front part of the base is formed by two-color molding or insert molding, and the core holder is made of a soft material and protrudes forward from the front part of the core holder. A mechanical pencil is known in which core holding portions are formed at substantially equal intervals in the circumferential direction, and the inner surface thereof is formed in a V-shaped cross section. (See Patent Document 1)

  The above-mentioned mechanical pencil has the advantage that even if writing is performed by pushing the shortened lead with the next lead held by the chuck, the short lead does not rotate, but there is an advantage that when the chuck is closed after feeding the lead The next lead was retracted by the chuck, and a gap was formed between the short lead and the next lead, and the short lead bounced when writing was started.

Japanese Patent No. 4567717

  The problem to be solved is that the short lead bounces when writing is started after the lead is drawn out.

  In the present invention, a fastener is connected to a core tank built in a shaft cylinder so as to be slidable in the longitudinal direction, and the fastener is urged rearward in the longitudinal direction by a return spring and can be moved a certain distance in the longitudinal direction. In addition, the chuck urged rearward in the longitudinal direction by the coil spring is received by the shaft cylinder, and the chuck is closed by pressing a fastener against the chuck head to hold the core, and further connected to the shaft cylinder. The most important feature is that a lead holder for holding the lead with an appropriate force is provided at the front part of the tip member.

  In the present invention, even when writing is performed by pressing a short lead that is no longer held by the chuck with the next lead, writing can be performed without rotating or bouncing the lead, and the chuck is moved backward in the longitudinal direction by a coil spring. Since it is biased, the advantage that the chuck is closed in the retracted position and held to hold the lead is obtained.

FIG. 1 is a cross-sectional view showing a writing state of the knock type mechanical pencil of Example 1 of the present invention. Example 1 FIG. 2 is an enlarged sectional view of a main part showing the lead guide and lead holder of the first embodiment. Example 1 FIG. 3 is an enlarged cross-sectional view of the main part showing the lead-out state of the knock mechanical pencil of the first embodiment. Example 1 FIG. 4 is an enlarged cross-sectional view of a main part showing a chuck expanded state of the knock mechanical pencil of the first embodiment. Example 1 FIG. 5 is an enlarged cross-sectional view of a main part showing a state where the short lead of the knock type mechanical pencil of Example 1 is in contact with the next lead. Example 1 FIG. 6 is an enlarged cross-sectional view of the main part showing a writing state of the knock mechanical pencil of Example 2 of the present invention. (Example 2) FIG. 7 is an enlarged cross-sectional view of the main part showing a writing state of the knock mechanical pencil of Example 3 of the present invention. (Example 3) FIG. 8 is an enlarged sectional view taken along line AA of FIG. (Example 3) FIG. 9 is an enlarged partial cross-sectional view of a main part showing a connection state between a fastener and a connector in the knock mechanical pencil of the third embodiment. (Example 3) FIG. 10 is an enlarged cross-sectional view of a main part showing a writing state of the knock mechanical pencil according to the fourth embodiment of the present invention. Example 4

  A knock type mechanical pencil that can write without causing the core to rotate or bounce even when a short core that is no longer held by the chuck is pressed with the next core and writing is achieved. .

  Hereinafter, based on FIG.1, FIG.2, FIG.3, FIG.4 and FIG. 5, the knock 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. A grip 3 made of a soft material such as rubber is attached to a grip portion 2A of a shaft cylinder 2 in which a clip 1 is formed at the rear, and a core tank 4 is built in the shaft cylinder 2 so as to be slidable in the longitudinal direction. A fastener 5 is press-fitted and connected to the front portion of the core tank 4, and a return spring 6 is attached between the inner stage 2B of the shaft tube 2 and the outer stage 5A of the fastener 5 with a load of about 500 g. Thus, the fastener 5 is urged backward in the longitudinal direction.

  The chuck 7 has a head portion 7B formed at the rear portion of the cylindrical portion 7A extending rearward from the front portion, and a taper portion 7C having a large diameter toward the rear in the longitudinal direction is formed on the head portion 7B. The head 7B has a plurality of grooves formed from the rear to the front, and the head 7B is divided into a plurality of parts. Further, an outer cylinder portion 7D is formed extending rearward from the front portion of the chuck 7, and an outer collar 7E is formed at the rear end of the outer cylinder portion 7D. The head 7B of the chuck 7 is inserted into the fastener 5, the taper portion 7C of the chuck 7 is pressed against the inner collar 5B of the fastener 5, and the chuck 7 together with the fastener 5 is urged rearward in the longitudinal direction. The The chuck 7 has an outer flange 7E in contact with the front end of the shaft cylinder 2, the inner flange 5B of the fastener 5 is strongly pressed against the tapered portion 7C of the chuck 7, the head 7B of the chuck 7 is closed, and the core 8 is closed. Hold strong. Furthermore, the tip member 9 is detachably screwed to the front portion of the shaft tube 2. An inner step 9A is formed in the tip member 9, and an outer flange 7E of the chuck 7 is configured to be slidable in the longitudinal direction between the inner step 9A and the front end of the shaft tube 2.

  Further, a cylindrical plate holder 10 is formed by rolling a metal plate material such as stainless steel, phosphor bronze, beryllium copper or brass, and a kerf is formed in the front portion of the core holder 10 facing the alignment groove 10A. The front part of the lead holder 10 is divided into two pieces 10B by a matching groove 10A and a kerf. The two pieces 10B are bent inwardly into a curved shape, and the tip is formed in a trumpet shape. Further, the core guide 11 made of a stainless steel pipe material is formed with a reduced diameter at the tip. The lead holder 10 is inserted from the rear end side of the lead guide 11, the tip of the lead holder 10 is brought close to the tip of the lead guide 11, and the cylindrical rear portion of the lead holder 10 is press-fitted to the rear inner surface of the lead guide 11. Match. The core guide 11 is press-fitted and fixed to the front portion of the middle piece 12.

  The lead guide 11 and the middle piece 12 are inserted into the tip member 9, and a coil spring 13 is attached between the rear end of the middle piece 12 and the front end of the chuck 7 with a loading load of about 20 g, and a knock-type mechanical pencil is attached. Configure.

  In the knock type mechanical pencil described above, the fastener 5 is advanced by advancing the lead tank 4, and the lead 8 is fed out when the chuck 7 closed by the inner flange 5B of the fastener 5 is advanced. When the outer flange 7E of the chuck 7 comes into contact with the inner stage 9A of the tip member 9, the advance of the chuck 7 is stopped and the state shown in FIG. When the lead tank 4 is further advanced, the inner collar 5B of the fastener 5 is detached from the head 7B of the chuck 7, and the chuck 7 is expanded to release the lead 8. Then, the chuck 7 is urged rearward by the coil spring 13, and the outer flange 7E of the chuck 7 is instantaneously brought into contact with the front end of the shaft tube 2 to be in the state shown in FIG. Further, when the fastener 5 and the lead tank 4 move forward, the outer flange 7E of the chuck 7 is pressed against the inner stage 9A of the tip member 9 by being pushed by the lead tank 4, and the chuck 7 stops. Accordingly, the lead 8 is fed out by the length that the chuck 7 holds the lead 8 and advances. When the writing lead 8 is shortened by writing, the next lead 8 in the lead tank 4 follows and advances the shortened lead 8. In this case, when the short core 8 is drawn out by the core 8 held by the chuck 7, the outer collar 7E is brought into contact with the inner stage 9A of the tip member 9 and the advancement is stopped. The lead tank 4 further advances, and the fastener 5 is detached from the head 7B of the chuck 7. Then, the chuck 7 is instantaneously retracted by the coil spring 13 and the outer collar 7E of the chuck 7 comes into contact with the front end of the shaft tube 2. Thereafter, when the pressing of the lead tank 4 is released, the fastener 5 and the lead tank 4 are retracted, the inner flange 5B of the fastener 5 presses the tapered portion 7C of the chuck 7, and the chuck 7 is closed. When the chuck 7 is closed, the chuck 7 does not move backward, so that the core 8 held by the chuck 7 does not move backward at all. Therefore, the short lead 8 and the next lead 8 are always kept in contact with each other and are in the state shown in FIG.

  When writing is performed in this state, the short core 8 is held only by the core holder 10, but by holding the core 8 with two pieces 10 </ b> B formed at the front portion of the core holder 10, Since the core 8 is held near the tip and the rotation of the core 8 is prevented, the core 8 discharged as a remaining core becomes very small and very economical.

  Hereinafter, based on FIG. 6, the knock type mechanical pencil of Example 2 in this invention is demonstrated. In addition, the same member as FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits the description. The chuck 107 has a head portion 107B formed at the rear portion of the cylindrical portion 107A extending rearward from the front portion, and a tapered portion 107C having a large diameter toward the rear in the longitudinal direction is formed on the head portion 107B. The head 107B is formed with a plurality of kerfs from the rear to the front, and the head 107B is divided into a plurality. An inner collar 14A of the outer cylinder 14 is press-fitted and fixed to the front portion of the chuck 107. The head 107B of the chuck 107 is inserted into the fastener 5, the taper portion 107C of the chuck 107 is pressed against the inner flange 5B of the fastener 5, and the chuck 107 together with the fastener 5 is urged rearward in the longitudinal direction. The In the chuck 107, the rear end of the outer cylinder 14 is brought into contact with the front end of the shaft cylinder 2, the inner collar 5B of the fastener 5 is strongly pressed against the tapered portion 107C of the chuck 107, and the head 107B of the chuck 107 is closed. The core 8 is held firmly. The connector 15 is press-fitted and fixed to the rear portion of the fastener 5, and the rear portion 15 </ b> A of the connector 15 is press-fitted and fixed to the front portion of the lead tank 104 to connect the chuck 107 and the lead tank 104. Further, the front member 109 is detachably screwed to the front portion of the shaft tube 2. The coil spring 13 is attached with a load at the time of attachment of about 20 g between the rear end of the intermediate piece 12 incorporated in the tip member 109 and the front end of the chuck 107. The lead 8 feeding means is performed in the same manner as in the first embodiment.

  Hereinafter, based on FIG.7, FIG8 and FIG.9, the knock type mechanical pencil of Example 3 in this invention is demonstrated. In addition, the same member as FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits the description. The front shaft 17 is screwed into the front portion of the rear shaft 16 in which a clip is formed at the rear portion to constitute a shaft cylinder. An inner shaft 18 is slidably incorporated in the front shaft 17 in a longitudinal direction, and a writing pressure spring 19 is attached between the rear end of the inner shaft 18 and the front end of the rear shaft 16 with a load of about 500 g at the time of installation. The inner shaft 18 is urged forward in the longitudinal direction.

  The chuck 207 has a head portion 207B formed at the front portion of the cylindrical portion 207A extending forward from the rear portion, and the head portion 207B is formed with a tapered portion 207C having a large diameter toward the rear in the longitudinal direction. The head 207B has a plurality of kerfs from the front to the rear, and the head 207B is divided into a plurality of parts. Further, the outer cylinder 114 is press-fitted and fixed to the rear part of the chuck 207, and an outer protrusion 114B formed at a relative position of the outer cylinder 114 is formed between the inner stage 17A of the front shaft 17 and the front end of the inner shaft 18 in the longitudinal direction. Is slidably inserted in the case. Accordingly, the chuck 207 is received by the rear shaft 16 via the outer cylinder 114, the inner shaft 18 and the writing pressure spring 19. In the fastener 105, a groove 105C extending forward from the rear end is formed at a relative position, and a locking window 105D is formed at a position shifted 90 degrees in the circumferential direction from the groove 105C. The fastener 105 is covered from the front of the chuck 207, and the outward projection 114B of the outer cylinder 114 is inserted into the groove 105C of the fastener 105. The front portion of the connector 115 is inserted into the rear portion of the fastener 105, and a raised portion 115 </ b> B formed opposite to the front portion of the connector 115 is inserted into the groove 105 </ b> C of the fastener 105, and at the front portion of the connector 115. A protrusion 115C formed opposite to the raised portion 115B and a position shifted by 90 degrees in the circumferential direction engages with a locking window 105D of the fastener 105, and the fastener 105 and the connector 115 are connected. The return spring 6 is attached between the raised portion 115B of the connector 115 and the inner flange 18A of the inner shaft 18 with a load of about 500 g at the time of attachment, and urges the connector 115 and the fastener 105 rearward in the longitudinal direction. Then, the outward projection 114B of the outer cylinder 114 comes into contact with the front end of the inner shaft 18, the inner collar 105B of the fastener 105 is strongly pressed against the tapered portion 207C of the chuck 207, and the head 207B of the chuck 207 is closed to close the core. Hold 8 strongly. Further, the front part of the lead tank 104 is press-fitted and fixed to the rear part 115A of the connector 115, and the fastener 105 and the lead tank 104 are connected. Furthermore, the front member 209 is detachably screwed to the front portion of the front shaft 17. A coil spring 113 is attached between the rear end of the middle piece 12 incorporated in the tip member 209 and the front end of the chuck 207 with a load at the time of attachment of about 20 g, and a knock type mechanical pencil is configured.

  In the knock type mechanical pencil described above, the fastener 105 is advanced by advancing the lead tank 104, and the lead 8 is fed out when the chuck 207 closed by the inner collar 105B of the fastener 105 is advanced. Then, when the outward projection 114B of the outer cylinder 114 contacts the inner stage 17A of the front shaft 17, the advancement of the chuck 207 stops. When the lead tank 104 is further advanced, the inner collar 105B of the fastener 105 is disengaged from the head 207B of the chuck 207, and the chuck 207 is expanded to release the lead 8.

  Further, when a strong writing pressure is applied to the core 8 when writing is performed, the inner shaft 18 with which the outer protrusion 114B of the outer cylinder 114 abuts moves backward together with the chuck 207 and the outer cylinder 114, and the writing pressure spring 19 Therefore, even when a strong writing pressure more than necessary is applied to the core 8, breakage of the core 8 can be prevented.

  Hereinafter, based on FIG. 10, the knock type mechanical pencil of Example 4 in this invention is demonstrated. A sliding window 118B is formed at a relative position on the inner shaft 118, and a fastener 205 is incorporated in the inner shaft 118 so as to be slidable in the longitudinal direction. Further, the return spring 6 is attached between the inner stage 118C of the inner shaft 118 and the outer stage 205A of the fastener 205 with a load of about 500 g at the time of attachment, and urges the fastener 205 rearward in the longitudinal direction.

  The outer cylinder 214 is press-fitted and fixed to the rear part of the chuck 307, and the outer projection 214B of the outer cylinder 214 is inserted through the groove 205C of the fastener 205 so as to be slidable appropriately in the longitudinal direction on the sliding window 118B of the inner shaft 118. Engaged. Further, the head portion 307B of the chuck 307 is inserted into the fastener 205, the tapered portion 307C of the chuck 307 is strongly pressed against the inner flange 205B of the fastener 205, the head portion 307B of the chuck 307 is closed, and the core 8 is closed. Hold strong. A coil spring 213 is attached between the inner stage 205E of the fastener 205 and the outer cylinder 214 with an attachment load of about 20 g. Then, the protrusion of the connector 215 engages with the locking window of the fastener 205, and the fastener 205 and the connector 215 are connected. Further, the core tank 104 is press-fitted and connected to the rear portion 215A of the connector 215. Further, the inner shaft 118 is inserted into the shaft cylinder 102, and the front member 309 is detachably screwed into the front portion of the inner shaft 118, whereby the rear end of the front member 309 and the outer stage 118D of the inner shaft 118 are The inner flange 102C of the shaft cylinder 102 is held. In addition, the lead guide 11 having the lead holder 10 incorporated therein is press-fitted and fixed in the tip member 309.

  In addition, this invention is not limited to the said Example, Members, such as a shaft cylinder, a chuck | zipper, a core tank, a fastener, an outer cylinder, a tip member, and a middle piece, fix and integrate a plurality of members. It is also possible. The means for receiving the chuck with the shaft cylinder is not limited to the configuration in which the chuck is directly brought into contact with the shaft cylinder, and there is no problem with the configuration in which the chuck is received with the shaft cylinder via another member.

  Even when a short lead that is no longer held by the chuck is pressed with the next lead and writing is performed, the lead can be written without rotating or bouncing, and can be applied to a knock type mechanical pencil that can reduce the remaining lead very much.

2 shaft cylinder 4 core tank 5 fastener 6 return spring 7 chuck 7B chuck 7 head 8 core 9 tip member 10 core holder 13 coil spring 102 shaft cylinder 104 core tank 105 fastener 107 chuck 107B chuck 107 head 109 tip Member 113 Coil spring 205 Clamp 207 Chuck 207B Chuck 207 head 209 Lead member 213 Coil spring 307 Chuck 307B Chuck 307 head 309 Lead member

Claims (1)

  A fastener is connected to a core tank built in the shaft cylinder so as to be slidable in the longitudinal direction, and this fastener is urged rearward in the longitudinal direction by a return spring, and can be moved a certain distance in the longitudinal direction, and is a coil spring. The chuck urged rearward in the longitudinal direction by the shaft cylinder is received by the shaft cylinder, and the chuck is closed by pressing a fastener against the head of the chuck to hold the core, and further, in front of the tip member connected to the shaft cylinder. A knock-type mechanical pencil that has a core holder that holds the core with an appropriate force at the center.

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