JP2012030426A - Mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical pencil configured so that a residual lead no longer held by a chuck 7 can be easily discharged without the risk of discharging the next lead 12 in the discharge of the residual lead.SOLUTION: An expansion member is disposed at a rear portion of a built-in lead holder 2 of a tip member 6 so as to be slidable in the longitudinal direction. The expansion member is biased backward in the longitudinal direction by a spring 5. A mechanism unit including the chuck 7 and a chuck spring 11 is biased backward in the longitudinal direction by a return spring 15 having an attachment load smaller than the attachment load of the chuck spring 11. The mechanical pencil includes a fixing means capable of releasing the mechanism unit. Further, the lead holder 2 includes an elastic piece 2B, and the lead 12 is held with an appropriate force by this elastic piece 2B. The mechanism unit is set in a fixed state to deliver the lead 12, and the mechanism unit is set in a released state and moved forward, thereby the expansion member is pressed and moved forward by the mechanism unit. The elastic piece 2B of the lead holder 2 is expanded by this expansion member to discharge the residual lead.

Description

  The present invention relates to a mechanical pencil that can easily discharge a remaining core that can no longer be held by a chuck.

  Conventionally, the head part of the chuck is composed of a front taper part and a rear taper part, a middle piece is fixed to a guide pipe having a through window at an appropriate position, and a front tightening ring and a core holder are constructed in the base. The lead holder is recessed from the guide pipe through-hole that holds the center piece to hold the lead, and the return spring has a resilient force stronger than the guide pipe holding force of the lead holder provided between the base and the center piece. Thus, there is known a knock-type mechanical pencil constituted by abutting the middle piece against the front end of the chuck. (See Patent Document 1)

  However, the knock type mechanical pencil has a risk that the lead holder may be worn out and the next lead may be discharged.

Japanese Utility Model Publication No. 55-10726

  The problems to be solved are that the lead holder is rubbed and worn by the guide pipe, and that the next lead is discharged when the remaining lead is discharged.

  In the present invention, a lead holder is built in the tip member, and an expanding member is slidably disposed in the longitudinal direction at the rear of the lead holder, and the expanding member is urged rearward in the longitudinal direction by a spring, and a chuck And a fastener that is externally fitted to the chuck, a coupling that receives the fastener, and a chuck spring that biases the chuck rearward in the longitudinal direction. A fixing means for urging the mechanism part in the longitudinal direction with a return spring having a mounting load smaller than the load is provided, and an elastic piece is formed on the core holder, and the core is formed with an appropriate force by the elastic piece. Hold and advance the core by advancing the chuck with the mechanism part fixed, and push the expansion member at the mechanism part by advancing the mechanism part with the mechanism part released Advanced Te, characterized by discharging a residual core of shortened not held by the chuck by spreading the resilient piece wick holder by expanding element.

  The present invention can easily discharge a shortened remaining core that is not held by the chuck, improves the durability of the core holder, and may cause the next core to be discharged when the remaining core is discharged. There are no advantages.

FIG. 1 is a cross-sectional view showing a writing state of the mechanical pencil according to the first embodiment of the present invention. Example 1 FIG. 2 is a development view showing the relationship between the selection ring and the piece of FIG. Example 1 FIG. 3 is an enlarged cross-sectional view showing the AA line of FIG. Example 1 FIG. 4 is a cross-sectional view of the main part showing the remaining core discharge state in the mechanical pencil according to the first embodiment of the present invention. Example 1 FIG. 5 is a development view showing the relationship between the selection ring and the piece of FIG. Example 1 FIG. 6 is an enlarged cross-sectional view of the main part showing the remaining core discharge state of FIG. Example 1 FIG. 7 is a cross-sectional view showing a writing state in the mechanical pencil of Example 2 of the present invention. (Example 2) 8 is a bottom view of the main part of FIG. (Example 2) FIG. 9 is a cross-sectional view of the main part showing the writing state of the mechanical pencil according to the third embodiment of the present invention. (Example 3) FIG. 10 is a cross-sectional view of the main part showing the remaining core discharge state in the mechanical pencil according to the third embodiment of the present invention. (Example 3)

  A short pencil that can no longer be held by the chuck can be easily discharged, and a mechanical pencil that improves the durability of the lead holder has been realized.

  Hereinafter, the mechanical pencil according to the first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6. Moreover, let the left side of FIG. 1 be the front, and let the right side be back. First, the core holder 2 made of synthetic resin is press-fitted and fixed to the rear part of the metal guide pipe 1. An outer collar 2A is formed on the core holder 2 and three elastic pieces 2B extending rearward in the longitudinal direction are formed at equal intervals in the circumferential direction. Further, a front inner collar 3A is formed at the front end of the synthetic resin middle piece 3, and the front part of the middle piece 3 is formed in half by a kerf. Moreover, the metal expansion pipe 4 is fixed to the rear inner flange 3B formed at the rear end of the middle piece 3 so as to protrude forward from the rear inner flange 3B. The middle piece 3 and the expansion pipe 4 constitute an expansion member. The front inner collar 3A of the middle piece 3 is locked to the outer collar 2A of the core holder 2, and a spring having a mounting load of about 50 g between the outer collar 2A of the core holder 2 and the rear inner collar 3B of the middle piece 3 5 is attached and the middle piece 3 is urged rearward in the longitudinal direction. The guide pipe 1, the core holder 2, the middle piece 3, the expansion pipe 4 and the spring 5 are built in the tip member 6 so as to be slidable in the longitudinal direction.

  Further, a fastener 8 is externally fitted to the head portion 7A of the chuck 7 whose front part is divided into a plurality, and the fastener 8 is loosely fitted in the concave groove 9A of the connector 9 so as to be slidable in the longitudinal direction. A lead tank 10 is press-fitted and fixed to the rear part of the chuck 7, and a chuck spring 11 having an attachment load of about 300 g is attached between the front end of the lead tank 10 and the inner flange 9 </ b> B of the connector 9. Energize backward in the longitudinal direction. The head 7A of the chuck 7 urged rearward in the longitudinal direction is pressed by the fastener 8 and the chuck 7 is closed to hold the core 12 firmly. The fastener 8 is pressed against the inner collar 9B of the connector 9. A plurality of spare cores 12 are accommodated in the core tank 10 to constitute a mechanism unit.

  Furthermore, an opening groove 13A extending in the longitudinal direction as appropriate in the longitudinal direction is formed in the middle portion of the shaft tube 13, the mechanism portion is inserted from the rear of the shaft tube 13, and the piece 14 inserted through the opening groove 13A of the shaft tube 13 is connected. It is press-fitted and fixed in the locking hole 9C of the tool 9. The upper end 14A of the piece 14 is formed wider than the lower end as shown in FIG. Further, a return spring 15 having an attachment load of about 200 g is attached between the inner stage 13B of the shaft tube 13 and the outer stage 9D of the connector 9, and the mechanism portion is urged rearward in the longitudinal direction, and the piece 14 is attached to the shaft tube. It is made to contact | abut to the rear-end edge of 13 opening grooves 13A. Further, an L-shaped groove comprising a fixing groove 16A extending in the circumferential direction and a sliding groove 16B extending in the longitudinal direction is formed on the inner surface of the cylindrical selection ring 16, and in this groove, the piece 14 is formed. The upper part is engaged. The selection ring 16 is attached to the shaft cylinder 13 so as to be rotatable and immovable in the longitudinal direction. The tip member 6 is detachably screwed to the front portion of the shaft tube 13, and a rubber grip 17 is provided between the tip member 6 and the selection ring 16 to constitute a knock type mechanical pencil.

  The mechanical pencil normally performs writing in the writing state shown in FIGS. 1 and 2 by engaging the piece 14 fixed to the connector 9 with the fixing groove 16A of the selection ring 16. When the lead 12 is fed out, the chuck 7 is advanced by pressing the lead tank 10 to feed out the lead 12. At this time, since the piece 14 is fixed by the piece 14 being engaged with the fixing groove 16A of the selection ring 16, the connection tool 9 does not move forward. Accordingly, the fastener 8 together with the chuck 7 advances in the concave groove 9 </ b> A of the connector 9, and the core 12 is fed out.

  In addition, when writing causes the core 12 to wear and the core 12 has a length (remaining core) that cannot be held by the chuck 7, the selection ring 16 is rotated to slide the piece 14 on the selection ring 16. Engage with the moving groove 16B. When the lead tank 10 is pressed in this state, since the attachment load of the chuck spring 11 is larger than the attachment load of the return spring 15, the return spring 15 is compressed and the mechanism part advances. At this time, the piece 14 moves forward in the sliding groove 16B. Then, the front end of the chuck 7 comes into contact with the rear end of the middle piece 3 to advance the middle piece 3. Then, the expansion pipe 4 moves forward together with the middle piece 3, the expansion pipe 4 is inserted into the elastic piece 2B of the core holder 2, the elastic piece 2B is expanded, and the remaining core discharge state shown in FIGS. To. Then, when the tip of the writing instrument is directed downward, the remaining core held by the elastic piece 2B is dropped from the tip of the guide pipe 1 and discharged as shown in FIG. At this time, since the chuck 7 is closed, there is no possibility that the core 12 in the core tank 10 is dropped through the chuck 7. After the remaining core is discharged, if the selection ring 16 is rotated again to engage the piece 14 with the fixed groove 16A, the writing state shown in FIGS. 1 and 2 is obtained. If the lead tank 10 is pressed in this state, no remaining lead remains in the lead holder 2, so that the next lead 12 is immediately followed and writing can be performed.

  Hereinafter, based on FIG.7 and FIG.8, the 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. An L-shaped groove comprising a fixed groove 113C extending in the circumferential direction and a sliding groove 113D extending in the longitudinal direction is formed in the rear portion of the shaft tube 113. Further, the connecting tool 109 constituting the mechanism portion is formed to extend to the rear part of the shaft tube 113, and an elastic piece 109E extending backward is formed at the rear part of the connecting tool 109, and a protrusion 109F is formed on the elastic piece 109E. To do.

  The mechanism portion is inserted from the rear side of the shaft tube 113, the elastic piece 109E of the connector 109 is bent inward to engage the protrusion 109F with the groove of the shaft tube 113, and a part of the protrusion 109F is connected to the shaft tube. A knock-type mechanical pencil is formed by protruding from 113.

  In the mechanical pencil, the protrusion 109F of the connector 109 is usually engaged with the fixing groove 113C of the shaft tube 113, and writing is performed in the writing state shown in FIGS. When the lead 12 is fed out, the chuck 7 is advanced by pressing the lead tank 110 to feed out the lead 12. At this time, the connecting tool 109 does not move forward because the protrusion 109F is engaged with the fixing groove 113C of the shaft tube 113 and fixed. Accordingly, the fastener 8 together with the chuck 7 advances in the concave groove 109 </ b> A of the connector 109 and the lead 12 is fed out.

  In addition, when writing causes the core 12 to wear and the core 12 has a length that cannot be held by the chuck 7, the projection 109 F of the connector 109 is operated to slide the projection 109 F of the shaft tube 113. Engage with the moving groove 113D. When the lead tank 110 is pressed in this state, the protrusion 109F advances in the sliding groove 113D and the mechanism advances in a state where the chuck 7 is closed, and the remaining lead is discharged as in the first embodiment. After the remaining core is discharged, if the protrusion 109F of the connector 109 is operated again to engage the protrusion 109F with the fixing groove 113C of the shaft tube 113, the writing state shown in FIGS.

  Hereinafter, the mechanical pencil according to the third embodiment of the present invention will be described with reference to FIGS. 9 and 10. In addition, the same member as FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits the description. A rear inner collar 103B is formed at the rear end of the middle piece 103 constituting the expanding member, and an outer collar 103C is formed at the rear end of the middle piece 103. The expansion pipe 4 is fixed to the rear inner flange 103B. The middle piece 103 and the expansion pipe 4 constitute an expansion member. Further, the guide pipe 1, the core holder 2, the middle piece 103, the expansion pipe 4 and the spring 5 are incorporated in the tip member 106 so as to be slidable in the longitudinal direction. Further, the front end of the connector 209 is configured to be able to contact the outer casing 103C of the middle piece 103 to constitute a knock type mechanical pencil.

  The mechanical pencil normally performs writing in the writing state shown in FIG. 9 by engaging the piece 14 fixed to the connector 209 with the fixing groove 16A of the selection ring 16. When the lead 12 is worn and cannot be held by the chuck 7, the selection ring 16 is rotated to engage the piece 14 with the sliding groove 16 </ b> B of the selection ring 16. When the lead tank 10 is pressed in this state, the return spring 15 is compressed and the mechanism advances. Then, the front end of the connector 209 abuts against the outer casing 103C of the middle piece 103, and moves the middle piece 103 forward. Then, the expansion pipe 4 moves forward together with the middle piece 103, the expansion pipe 4 is inserted into the elastic piece 2B of the core holder 2, and the elastic piece 2B is expanded to the remaining core discharge state shown in FIG. Then, the remaining core held by the elastic piece 2B is dropped from the tip of the guide pipe 1 and discharged. At this time, since the chuck 7 is closed, there is no possibility that the core 12 in the core tank 10 is dropped through the chuck 7. After the remaining core is discharged, if the selection ring 16 is rotated again to engage the piece 14 with the fixed groove 16A, the writing state shown in FIG. 9 is obtained.

  The present invention is not limited to the above-described embodiments, and a plurality of members such as a shaft tube, a tip member, a connector, a core holder, a center piece, a guide pipe, a core tank, a selection ring, and a piece are fixed to each other. May be integrated. Moreover, it is also possible to comprise a connector and a piece integrally by one part. Furthermore, the protrusion formed integrally with the connector can be configured by fixing another component and integrating it.

  The present invention can be applied to a mechanical pencil that can easily discharge a short remaining core that is no longer held by the chuck and that does not cause the next core to be discharged when the remaining core is discharged.

2 core holder 2B elastic piece of core holder 2 5 spring 6 tip member 7 chuck 8 fastener 9 coupling tool 11 chuck spring 12 core 15 return spring 106 tip member 109 coupling tool 209 coupling tool

Claims (1)

  A lead holder is incorporated in the tip member, and an expansion member is slidably disposed in the longitudinal direction at the rear of the lead holder. The expansion member is urged rearward in the longitudinal direction by a spring, and the chuck and chuck A mechanism part is configured to include an externally fitted fastener, a coupling tool that receives the fastener, and a chuck spring that biases the chuck rearward in the longitudinal direction, and the mechanism part is mounted smaller than the chuck spring mounting load. A fixing means that urges the longitudinal direction rearward by a return spring of the load and releases the mechanism part is provided, and further, an elastic piece is formed on the core holder, and the core is held with an appropriate force by the elastic piece. The core is extended by advancing the chuck with the part fixed, and the expansion member is pushed forward by the mechanical part by advancing the mechanical part with the chuck released and expanded. Mechanical pencil, characterized in that for discharging the residual core of shortened not held by the chuck by spreading the resilient piece wick holder by wood.

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