JP2012111139A - Mechanical pencil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical pencil to which a rotating means that is a slide member 13 with a simple structure hardly breaks down and can rotate a lead 6 by a fixed amount whenever writing pressure is exerted can be applied.SOLUTION: A chuck unit is incorporated in a barrel 7 so that the chuck unit can be rotated to only one direction and be moved slightly to the longitudinal direction. The chuck unit is pressed forward by a return spring 11. The slide member 13 is incorporated in a front member 12 so that the slide member can be slid to the longitudinal direction. As the chuck unit is moved backward by writing pressure, the lead 6 and the slide member 13 are also moved backward. As a result, the rotating means rotates the slide member 13 to one direction. When the writing pressure is relieved, the chuck unit is moved forward and accordingly the slide member 13 is also moved forward. As the slide member 13 is moved forward, the rotating means rotates the slide member 13 to the direction opposite to the one direction when the slide member is moved backward. The lead 6 and the chuck unit are rotated to one direction by the fixed amount by the rotating means when the slide member 13 is moved forward.

Description

  The present invention relates to a mechanical pencil that rotates the core and the chuck unit by a certain amount when the slide member moves backward together with the lead when the chuck unit moves backward due to the writing pressure, and the slide member moves forward when the writing pressure is released.

  2. Description of the Related Art Conventionally, in a mechanical pencil capable of feeding a writing core by a predetermined amount in the axial direction, a chuck holder disposed in a shaft cylinder and reciprocating in the axial direction, and housed in the chuck holder and reciprocating in the axial direction A chuck portion that reciprocates in the axial direction, a slider having a core holding portion that holds the writing core, and reciprocating the slider in the axial direction. A mechanical pencil is known that includes a feed mechanism that rotates at a predetermined angle in one direction at the center and a biasing means that biases the slider forward. (See Patent Document 1)

  However, the mechanical pencil has a complicated structure due to the feeding mechanism in which the slider is sequentially rotated in one direction.

JP 2010-94955 A

  The problem to be solved is that the rotary feed mechanism of the slider becomes complicated and easily breaks down.

  The present invention relates to a chuck, a fastener fitted on the head of the chuck, a chuck spring for biasing the chuck rearward, a connector for restricting the backward movement of the fastener, and a core connected to the rear portion of the chuck. A chuck unit is constituted by the tank, and this chuck unit is built in the shaft cylinder so that it can rotate only in one direction and can be moved slightly in the longitudinal direction, and the chuck unit is provided by a return spring provided between the shaft cylinder and the chuck unit. Can be slid in the longitudinal direction in the tip member by providing a tip member in the front part of the shaft cylinder and incorporating a lead holder that holds the lead with an appropriate holding force. As the chuck unit is retracted by the writing pressure of the writing core, the slide member retracts together with the core, and the slide member rotates in one direction as the slide member retracts. Rotating means which constitutes a rotating means and moves the slide member together with the core as the chuck unit advances by releasing the writing pressure, and rotates the slide member in the opposite direction to the backward movement as the slide member advances. The main feature is that the lead and the chuck unit are rotated in a certain direction in one direction by the rotation of the slide member when moving forward.

  The present invention is advantageous in that the rotating means of the slide member has a relatively simple structure and is unlikely to fail, and the core can be rotated by a certain amount each time writing pressure is applied.

FIG. 1 is a cross-sectional view showing a mechanical pencil of Example 1 of the present invention. Example 1 FIG. 2 is a cross-sectional view of the main part showing a writing state of the mechanical pencil according to the first embodiment of the present invention. Example 1 FIG. 3 is an explanatory diagram sequentially showing (a) to (e) the rotation operation of the slide member and the state in which the chuck unit is rotated only in one direction in the mechanical pencil according to the first embodiment of the present invention. Example 1 FIG. 4 is a cross-sectional view of the main part showing a mechanical pencil of Example 2 of the present invention. (Example 2) FIG. 5 is a plan view of the main part showing the mechanical pencil of FIG. (Example 2) FIG. 6 is a cross-sectional view of the main part showing the mechanical pencil of Example 3 of the present invention. (Example 3) 7 is a cross-sectional view taken along line AA of FIG. (Example 3)

  A mechanical pencil has been realized in which the rotation means of the slide member is relatively simple and hardly breaks down, and the core can be rotated by a certain amount each time writing pressure is applied.

  Hereinafter, the mechanical pencil according to the first embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3. Moreover, let the left side of FIG. 1 be the front, and let the right side be back. Further, the left rotation direction is set to the left rotation toward the front, and the right rotation direction is set to the right rotation toward the front. First, a front part of a metal chuck 1 made of brass or the like is divided into three parts, and a core tank 2 made of a synthetic resin pipe material is press-fitted and fixed to the rear part of the chuck 1. A fastener 3 is externally fitted on the head 1A of the chuck 1, and the fastener 3 is loosely fitted in the concave groove 4A of the connector 4 so as to be slidable in the longitudinal direction as appropriate. A chuck spring 5 is stretched between the inner stage 4B of the connector 4 and the front end of the lead tank 2, and the chuck 1 is urged rearward in the longitudinal direction. Then, the head 1A of the chuck 1 is pressed and closed by the fastener 3, and the core 6 is strongly held by the chuck 1 to constitute a chuck unit.

  Next, the chuck unit is inserted from the front of the shaft tube 7, and the inner shaft 8 is press-fitted and fixed to the front portion of the shaft tube 7. Between the rear end of the inner shaft 8 and the inner stage 7A of the shaft tube 7, an outer collar 4C of the connector 4 is incorporated so as to be slidable in the longitudinal direction as appropriate. In addition, a serrated cam surface 4 </ b> D composed of an inclined surface and a vertical surface that protrudes rearward in the circumferential direction rightward is formed on the rear end surface of the outer stage of the connector 4.

  Further, the front end of the cam member 9 is formed with a serrated cam surface 9A composed of an inclined surface and a vertical surface that are recessed backward toward the right in the circumferential direction. The cam member 9 is inserted from the rear side of the shaft cylinder 7 and is covered by the rear portion of the connector 4, and the key 9B of the cam member 9 is engaged with the key groove 7B of the shaft cylinder 7 so as to be movable in the longitudinal direction. However, it is configured so that it cannot rotate. Further, a return spring 11 is stretched between the step portion 9C of the cam member 9 and the front end of the sheath 10 connected to the rear portion of the shaft cylinder 7, and the front end of the cam member 9 contacts the cam surface 4D of the connector 4. Touched. The connector 4 is pushed by the cam member 9, and the outer collar 4 </ b> C of the connector 4 is brought into contact with the rear end of the inner shaft 8.

  A slide member 13 is built in the tip member 12 so as to be slidable in the longitudinal direction, and a lead holder 14 for holding the lead 6 with a holding force of about 50 g is built in the slide member 13. A front spring 16 is stretched with an attachment load of about 100 g between the inner stage 13A of the slide member 13 and the piece 15 press-fitted and fixed to the tip member 12, and the slide member 13 is moved rearward toward the right in the circumferential direction. The first cam 13B inclined so as to be recessed is brought into contact with the front cam 12A inclined so as to protrude rearward toward the right in the circumferential direction of the tip member 12. A second cam 13 </ b> C is formed at the rear end of the slide member 13 so as to protrude rearward toward the right in the circumferential direction. Further, a rear cam 15B is formed at the front end of the cylindrical portion 15A formed at the front portion of the piece 15 so as to be recessed rearward in the circumferential right direction. The tip member 12 is detachably screwed to the inner shaft 8.

  Further, an eraser support 17 is press-fitted and attached to the rear part of the core tank 2, and an eraser 18 is attached to the inside of the rear part of the eraser support 17, and a knob 19 that covers the eraser 18 is attached to and detached from the rear part of the eraser support 17. Can be fitted. The eraser 18 and the knob 19 protrude appropriately from the rear end of the sheath 10 to constitute a mechanical pencil.

  In the state shown in FIG. 1, when writing is performed, writing pressure is applied to the core 6, and the chuck unit and the core 6 are slightly retracted together with the slide member 13. 3A, 3B, and 3C, the first cam 13B of the slide member 13 is separated from the front cam 12A of the tip member 12, and the second cam 13C of the slide member 13 is moved to the piece 15. The slide member 13 contacts the rear cam 15B and moves backward while rotating in the right direction. Then, the lead 6 held by the lead holder 14 also tries to rotate rightward. However, the chuck 1 that holds the lead 6 is pressed against the fastener 3 by the head 1A, and the fastener 3 exerts a strong force on the connector 4. And a large frictional force is generated. In addition, the serrated cam surface 4D of the connector 4 is pressed against the serrated cam surface 9A of the cam member 9, and the cam member 9 has a vertical surface perpendicular to the cam surface 4D of the connector 4 in the clockwise direction of the connector 4. The rightward rotation of the cam surface 9A is restricted and the rightward rotation is restricted, and the chuck unit retreats without rotating, so that the outer collar 4C of the connector 4 contacts the inner stage 7A of the shaft cylinder 7. The slide member 13 rotates clockwise while the lead holder 14 slides back on the lead 6. Writing is performed in this state.

  Next, when writing is stopped, the writing pressure applied to the core 6 is released, and the chuck unit is urged by the return spring 11 to move forward. Then, the slide member 13 also moves forward together with the core 6 to be in the state of (c) to (d) and (e) in FIG. 3, and the first cam 13B of the slide member 13 contacts the front cam 12A of the tip member 12, The slide member 13 advances while rotating in the left direction. Accordingly, the lead 6 held by the lead holder 14 is also applied with a force in the left direction, and a force in the left direction is applied to the chuck unit. Then, the serrated cam surface 4D of the connector 4 slides on the serrated cam surface 9A of the cam member 9, and the chuck unit moves forward together with the slide member 13 and the core 6 while rotating to the left. When the outer collar 4C of the connector 4 comes into contact with the rear end of the inner shaft 8, the advancement of the chuck unit is stopped, and the slide member 13 also returns to the state shown in FIG. Therefore, the lead 6 is rotated by a certain amount together with the chuck unit. If writing is performed in this state, writing can be performed with the new edge portion of the core 6 sequentially hitting the paper without rotating the mechanical pencil.

  When the lead 6 is worn by writing, the knob 19 is pressed to advance the lead tank 2, and if the chuck 1 is advanced, the lead 6 is advanced together with the chuck 1, and the connecting tool The core 6 is fed out by the moving distance of the fastener 3 that moves in the four concave grooves 4A. Further, even when one lead 6 is consumed and shortened, the lead 6 in the lead tank 2 can be made to follow by moving the chuck 1 forward.

  Hereinafter, based on FIG.4 and FIG.5, 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. First, the guide groove 112B inclined in the clockwise direction toward the rear is formed in the tip member 112. A slide member 113 is slidably incorporated in the tip member 112, and the lead holder 14 is incorporated in the slide member 113. Further, a protrusion 20 is fixed to the rear portion of the slide member 113, and this protrusion 20 is engaged with the guide groove 112B of the tip member 112 described above. Further, the front spring 16 is stretched between the inner stage 113A of the slide member 113 and the piece 115 press-fitted and fixed to the tip member 112, and urges the slide member 113 forward in the longitudinal direction. The tip member 112 is detachably screwed to the inner shaft 8.

  In the state shown in FIG. 4, when writing is performed, writing pressure is applied to the core 6, and the chuck unit and the core 6 are slightly retracted together with the slide member 113. Then, the protrusion 20 provided on the slide member 113 slides along the guide groove 112B of the tip member 112, and the slide member 113 moves backward while rotating in the right direction. Then, the lead 6 held by the lead holder 14 also tries to rotate rightward. However, the chuck 1 that holds the lead 6 is pressed against the fastener 3 by the head 1A, and the fastener 3 exerts a strong force on the connector 4. And a large frictional force is generated. In addition, the serrated cam surface 4D of the connector 4 is pressed against the serrated cam surface 9A of the cam member 9, and the cam member 9 has a vertical surface perpendicular to the cam surface 4D of the connector 4 in the clockwise direction of the connector 4. The rightward rotation of the cam surface 9A is restricted and the rightward rotation is restricted, and the chuck unit retreats without rotating, so that the outer collar 4C of the connector 4 contacts the inner stage 7A of the shaft cylinder 7. The slide member 113 rotates clockwise while the lead holder 14 slides back on the lead 6. Writing is performed in this state.

  Next, when writing is stopped, the writing pressure applied to the core 6 is released, and the chuck unit is urged by the return spring 11 to move forward. Then, the slide member 113 moves forward together with the core 6, and the protrusion 20 of the slide member 113 slides along the guide groove 112B of the tip member 112, so that the slide member 113 moves forward while rotating in the left direction. Accordingly, the lead 6 held by the lead holder 14 is also applied with a force in the left direction, and a force in the left direction is applied to the chuck unit. Then, the serrated cam surface 4D of the connector 4 slides on the cam surface 9A of the cam member 9, and the chuck unit moves forward together with the slide member 113 and the core 6 while rotating to the left. When the outer collar 4C of the connector 4 comes into contact with the rear end of the inner shaft 8, the advancement of the chuck unit is stopped, and the slide member 113 also returns to the state shown in FIGS. Therefore, the lead 6 is rotated by a certain amount together with the chuck unit. If writing is performed in this state, writing can be performed with the edge portion of the core 6 sequentially hitting the paper without rotating the mechanical pencil.

  Hereinafter, the mechanical pencil according to the third embodiment of the present invention will be described with reference to FIGS. 6 and 7. In addition, the same member as FIG. 1 attaches | subjects the same code | symbol, and abbreviate | omits the description.

  A large number of locking teeth 104E are formed in the circumferential direction at an intermediate portion of the outer peripheral surface of the coupling unit 104 of the chuck unit. The locking teeth 104E are raised in the right rotation direction to form an inclined surface, and the right end surface of the inclined surface is formed perpendicular to the peripheral surface. Further, an outer casing 104 </ b> C is formed at the rear portion of the connector 104.

  Further, an elastic piece 108A is formed in the rear cylinder portion of the inner shaft 108 by cutting it into a U-shape, and a locking portion 108B that protrudes inwardly and has an end face on the left side is formed at the distal end portion of the elastic piece 108A. .

  A chuck unit is inserted into the inner shaft 108 from the rear, and the engaging portion 108B of the inner shaft 108 is engaged with the engaging teeth 104E of the connecting device 104. The connecting device 104 rotates only in the left direction with respect to the inner shaft 108. Configure as possible.

  The chuck unit and the inner shaft 108 are inserted from the front of the shaft tube 107, and the inner shaft 108 is press-fitted and fixed to the front portion of the shaft tube 107. In addition, an outer rod 104C of the connector 104 is incorporated so as to be slidable in the longitudinal direction as appropriate between the rear end of the inner shaft 108 and the inner stage 107A of the shaft tube 107. Further, the return spring 11 is stretched between the step portion 104F of the connector 104 and the front end of the sheath 10, and the connector 104 is urged forward in the longitudinal direction so that the outer collar 104C of the connector 104 is connected to the inner shaft 108. It is in contact with the rear end.

  In the state shown in FIGS. 6 and 7, when writing is performed, writing pressure is applied to the core 6, and the chuck unit and the core 6 are slightly retracted together with the slide member 13. Then, the first cam 13B of the slide member 13 is separated from the front cam 12A of the front member 12, the second cam 13C of the slide member 13 is pressed against the rear cam 15B of the piece 15, and the slide member 13 rotates rightward. Retreat while. Then, the lead 6 held by the lead holder 14 also tries to rotate to the right. However, the chuck 1 holding the lead 6 is pressed against the fastener 3 by the head 1A, and the fastener 3 exerts a strong force on the connector 104. And a large frictional force is generated. Further, the right end surface of the locking tooth 104E abuts against the end surface of the locking portion 108B of the inner shaft 108 with respect to the clockwise rotation direction of the coupling tool 104, and the chuck unit moves backward without rotating and moves out of the coupling tool 104. The flange 104 </ b> C contacts the inner stage 107 </ b> A of the shaft cylinder 107. The slide member 13 rotates clockwise while the lead holder 14 slides back on the lead 6. Writing is performed in this state.

  Next, when writing is stopped, the writing pressure applied to the core 6 is released, and the chuck unit is urged by the return spring 11 to move forward. Then, the slide member 13 also moves forward together with the core 6, the first cam 13B of the slide member 13 contacts the front cam 12A of the tip member 12, and the slide member 13 moves forward while rotating in the left direction. Accordingly, the lead 6 held by the lead holder 14 is also applied with a force in the left direction, and a force in the left direction is applied to the chuck unit. Then, the locking teeth 104E of the connector 104 slide on the locking portion 108B provided on the elastic piece 108A of the inner shaft 108, and the chuck unit moves forward together with the slide member 13 and the core 6 while rotating to the left. Then, when the outer flange 104C of the connector 104 comes into contact with the rear end of the inner shaft 108, the advancement of the chuck unit is stopped and the state returns to the state shown in FIG. Therefore, the lead 6 is rotated by a certain amount together with the chuck unit. If writing is performed in this state, writing can be performed with the new edge portion of the core 6 sequentially hitting the paper without rotating the mechanical pencil.

  Note that the present invention is not limited to the above-described embodiments, and the core holder can be used in various known shapes such as rubber or elastic pieces, and the slide member and the core holder are integrated. It may be configured. In addition, the members such as the shaft tube, the sheath, the connector, the tip member, the inner shaft, and the core tank are illustrated as one part for simplification of description, but two or more parts are screwed together. What is necessary is just to fit and integrate. Furthermore, the chuck is not limited to metal, and may be made of synthetic resin.

  The rotating means of the slide member becomes relatively simple and is not easily damaged, and can be applied to a mechanical pencil that can rotate the core by a certain amount each time writing pressure is applied.

DESCRIPTION OF SYMBOLS 1 Chuck 1A Head of chuck 1 2 core tank 3 Fastener 4 Connecting tool 5 Chuck spring 6 Core 7 Shaft cylinder 11 Return spring 12 Lead member 12A Front member 12 front cam 13 Slide member 13B First cam 13C of slide member 13 Second cam 14 of the slide member 14 Core holder 15 Frame 15B Rear cam 16 of the frame 15 Front spring 104 Connector 107 Shaft cylinder 112 Tip member 113 Slide member

Claims (2)

  The chuck unit includes a chuck, a fastener fitted to the chuck head, a chuck spring for biasing the chuck rearward, a connector for restricting the retraction of the fastener, and a core tank connected to the rear portion of the chuck. This chuck unit is built in the shaft cylinder so that it can rotate only in one direction and slightly move in the longitudinal direction, and the chuck unit is moved forward in the longitudinal direction by a return spring provided between the shaft cylinder and the chuck unit. In addition, a tip member is provided at the front portion of the shaft tube, and a slide member containing a lead holder for holding the lead with an appropriate holding force is incorporated in the tip member so as to be slidable in the longitudinal direction. As the chuck unit moves backward due to the writing pressure of the writing core, the sliding member moves backward together with the core, and the rotating member rotates the sliding member in one direction as the sliding member moves backward. As the chuck unit advances by releasing the writing pressure, the slide member advances together with the core, and the rotation member rotates the slide member in the opposite direction to the backward movement as the slide member advances. A mechanical pencil characterized in that the lead and the chuck unit are rotated in one direction by a certain amount by the rotation of the slide member when moving forward.   A front spring is provided between the slide member and the piece fixed to the tip member, and the front spring urges the slide member forward in the longitudinal direction to form a first cam and a second cam on the slide member, 2. The mechanical pencil according to claim 1, wherein a front cam is formed on the front member and a rear cam is formed on the frame to constitute a rotating means for the slide member.

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