JP4323920B2 - Swing-out mechanical pencil - Google Patents

Description

  The present invention relates to a swing-out type mechanical pencil that advances a chuck by an inertial force of a weight body and feeds a lead, and urges a pressing member backward in a longitudinal direction by a return spring.

Conventionally, an eraser support with an eraser is built in the shaft, and the inner shaft is screwed into the shaft, or an outer rod having the elasticity of the inner shaft is dropped into the shaft's concave groove. A swing-out mechanical pencil is known in which a shaft spring is provided between the shafts and an eraser support is urged rearward in the longitudinal direction. (See Patent Document 1)
Japanese Utility Model Publication No. 55-8181 (FIGS. 1 and 2)

  The problem to be solved is that if the inner shaft is screwed into the shaft, the eraser support and the shaft spring must be inserted and the inner spring must be screwed into the shaft while the shaft spring is contracted. Would be expensive. In addition, when the outer flange having the elasticity of the inner shaft is dropped into the groove of the shaft, the process of forming the groove on the inner surface of the shaft is very difficult, and the cost becomes high. In addition, when the eraser support is knocked to open the chuck, the elastic force of the shaft spring compressed and increased in pressure is directly applied to the inner shaft and the inner shaft may come off.

According to the present invention, in a swing-out mechanical pencil that advances a chuck by an inertial force of a weight body and feeds a lead, an inner collar is formed on a sheath, and a locking projection is formed on one of a pressing member and a core. And the other side is formed with a locking step, and a return spring is stretched between the pushing member inserted from the rear of the sheath and the inner collar of the sheath, and the core is inserted from the front, and the engaging step is engaged with the locking step. The core and the pressing member are connected by engaging the stop projection, the pressing member biased rearward in the longitudinal direction by the return spring is received by the core , and the weight body and the core can be contacted. Is the first gist.

  In addition, a front key groove or a front key that is positioned forward of the inner collar and extends rearward in the longitudinal direction is formed on the inner surface of the sheath, and a rear key groove that is positioned rearward of the inner collar and extends forward in the longitudinal direction. Alternatively, the rear key is formed, and the key or key groove formed on the core is engaged with the front key groove or front key of the sheath, and the key or key groove formed on the pressing member is engaged with the rear key groove or rear portion of the sheath. The second gist is that the front locking step and the locking projection are automatically aligned by engaging the key.

  Furthermore, the third gist is that an eraser is attached to the pressing member.

  The swing-out type mechanical pencil of the present invention can be produced at low cost by easily connecting the core and the pressing member, and when the return spring is compressed by advancing the pressing member, the force of the return spring is reduced. Since it is received with a scissors, there is an advantage that there is no possibility that the core and the pressing member come off.

  By engaging the locking projection with the locking step, the core and the pressing member are connected, and the return spring is stretched between the inner collar of the sheath and the pressing member, so that it can be produced at low cost and the return spring Since the return spring force is not applied to the core when it is compressed, a swing-out mechanical pencil that does not cause the core to come off has been realized.

  Embodiment 1 of the present invention will be described below with reference to FIGS. 1, 2, 3 and 4. FIG. Moreover, let the left side of FIG. 1 be the front, and let the right side be back. First, a polyacetal connector 2 is press-fitted and fixed to the rear part of a metal chuck 1 made of brass or the like. The rear portion of the connector 2 is press-fitted and fixed to the front portion of the core tank 3 made of polypropylene pipe material, and the flange portion 2 </ b> A of the connector 2 contacts the front end of the core tank 3. Further, a fastening ring 4 is fitted on the head 1 </ b> A of the chuck 1, and a spring 6 is stretched between the connector 5 that receives the fastening ring 4 and the connector 2.

  Next, the cylinder 7 will be described. The core tank 3 and the connector 2 can be inserted through the front hole 7A of the cylinder 7. Further, an anti-slip rubber grip 8 is externally fitted to the front narrow diameter portion 7B of the body 7. The rubber grip 8 is configured to be translucent and configured to be visible inside.

  The outer sheath 9 made of transparent resin is integrally formed with a clip 10, and an inner collar 9 </ b> A is formed at the rear portion of the outer sheath 9. Further, a concave groove 9B extending in the longitudinal direction is formed in the inner flange 9A. In addition, an outer collar 11A is formed at the rear part of the sheath 11, and a protrusion 11B extending forward in the longitudinal direction from the outer casing 11A is formed. The protrusions 11B are opposite in the circumferential direction at positions appropriately spaced in the longitudinal direction. Two engaging protrusions 11C and 11D extending in the direction are formed. In addition, the two engaging protrusions 11C and 11D are both formed on inclined surfaces that incline backward as the front ends 11E and 11F go from the protrusion 11B in the circumferential direction. Further, on the inner surface of the sheath 11, an inner collar 11G is formed slightly rearward from the middle portion, and two front keys 11H extending rearward in the longitudinal direction from the front end are inclined 45 degrees in the circumferential direction from above and below. Moreover, two rear key grooves 11I that are formed opposite to each other and extend forward in the longitudinal direction from the rear end are formed opposite to each other.

  The core 12 has an inner flange 12A formed at the front portion, and an engaging window 12C is formed by forming an opening window 12B at a position opposite to the intermediate portion. Further, two key grooves 12D are formed on the outer surface of the core 12 at a position inclined by 45 degrees in the circumferential direction from the opening window 12B.

  Two locking projections 13A are formed at relative positions above and below the front outer surface of the pressing member 13, and the front ends of the locking projections 13A are inclined. Moreover, the opening window 13B is formed in the both sides of the pushing member 13, and the front part of the pushing member 13 is formed so that bending is possible. An outer casing 13C is formed at the rear portion of the pressing member 13, and two keys 13D protruding outward are formed on the outer casing 13C so as to face each other. Further, an eraser 14 is fitted and attached to the rear inner hole 13E of the pressing member 13, and a knob 15 covering the eraser 14 is fitted to the rear outer surface 13F of the pressing member 13.

  The core 12 is inserted from the front of the sheath 11 with the key groove 12 </ b> D of the core 12 aligned with the front key 11 </ b> H of the sheath 11. The front part of the front key 11H is formed with a narrower width toward the front, so that the key groove 12D can be easily inserted. Further, the pushing member 13 is inserted from the rear side of the sheath 11 with the key 13D of the pushing member 13 fitted into the rear key groove 11I of the sheath 11, and returned between the inner collar 11G of the sheath 11 and the outer collar 13C of the pushing member 13. The spring 16 is stretched. When the pressing member 13 is inserted as appropriate, the locking projection 13A of the pressing member 13 is engaged with and attached to the opening window 12B of the core 12. At this time, since the key groove 12D of the core 12 is fitted to the front key 11H of the sheath 11 and the key 13D of the push member 13 is fitted to the rear key groove 11I of the sheath 11, the locking protrusion 13A of the push member 13 is It fits securely into the opening window 12B of the core 12. Therefore, the locking protrusion 13A of the push member 13 is normally locked to the locking step 12C of the core 12.

  The sheath 11 is inserted into the outer sheath 9 from the rear. At this time, first, the engaging protrusion 11C on the front side is inserted into the concave groove 9B of the outer sheath 9, and then the rear side of the outer sheath 9 is rotated while the sheath 11 is rotated. The engaging protrusion 11D is inserted into the concave groove 9B of the outer sheath 9. Since the engaging protrusions 11C and 11D are formed on the inclined surfaces in which the front ends 11E and 11F are inclined rearwardly from the protrusion 11B in the circumferential direction, the engagement of the sheath 11 with the concave groove 9B of the outer sheath 9 is achieved. When the protrusions 11C and 11D are inserted, the sheath 11 is naturally rotated, and any of the engagement protrusions 11C and 11D is smoothly inserted.

  The core tank 3 is inserted from the front of the barrel 7, and the connector 5 is held by the inner stage 17 </ b> A of the base 17 screwed to the front end of the barrel 7 and the front portion of the barrel 7. Further, the rubber grip 8 is held by the rear end of the base 17 and the outer flange 7 </ b> C of the body 7. The base 17 incorporates a core holder 19 made of an elastic body such as rubber that holds the core 18 with an appropriate force.

  The weight body 20 is made of stainless steel, and the weight body 20 is slidably built into the body 7 from the rear end of the body 7. The lead tank 3 is inserted into the weight body 20.

  Next, the sheath 11 is detachably screwed onto the barrel 7, and the outer sheath 9 is held by the outer collar 7 </ b> C of the trunk 7 and the outer collar 11 </ b> A of the sheath 11. Further, the weight body 20 incorporated in the body 7 is configured to be slidable in the longitudinal direction between the flange portion 2A of the connector 2 and the inner flange 12A of the core 12.

  The swinging mechanical pencil described above exerts an inertial force on the weight body 20 by shaking, and the weight body 20 comes into contact with the flange portion 2 </ b> A of the connector 2. Then, the inertial force of the weight body 20 is transmitted to the connector 2, the chuck 1 and the lead tank 3 are moved forward together with the connector 2, and a certain amount of lead 18 is fed out.

  Further, since the weight body 20 generated when shaken is brought into contact with the front end of the core 12 and no load is generated on the pressing member 13, there is no possibility that the pressing member 13 is detached due to the inertial force of the weight body 20.

  Further, when the pressing member 13 is pressed to return the protruding core 18, the force of the return spring 16 that is compressed and increased is received by the inner collar 11G of the sheath 11, and therefore the force of the return spring 16 is also applied to the core 12. No load is generated in the engagement of the pressing member 13, and there is no possibility that the pressing member 13 is detached.

  Moreover, since it is not necessary to form an opening window in the sheath 11 in order to engage the push member 13, the appearance is not impaired.

  Furthermore, when the sheath 11 is removed from the body 7, the two engaging protrusions 11 </ b> C and 11 </ b> D separated from the front and rear of the sheath 11 are engaged with the concave groove 9 </ b> B of the outer sheath 9. Since the sheath 11 cannot be removed unless it first rotates in the opposite direction and then in the forward direction, it is configured to be very difficult to come off.

  Furthermore, since the internal parts can be visually observed from the translucent rubber grip 8 and the transparent outer sheath 9, a novel design appearance can be obtained and a very excellent advantage can be obtained. The same advantage can be obtained even if the outer sheath 9 is colored and transparent.

  5, FIG. 6, and FIG. 7 show Embodiment 2 of the present invention, and the same members as those in FIG. First, an inner collar 111G is formed on the inner surface of the sheath 111 slightly behind the middle portion, and the two front keyways 111J extending in the longitudinal direction rearward from the front end are inclined 45 degrees in the circumferential direction from the top and bottom. In addition, two rear keys 111K that are formed opposite to each other and extend forward in the longitudinal direction from the rear end are formed opposite to each other.

  The core 112 has an inner flange 112A formed at the front, and an engaging window 112C is formed by forming an opening window 112B at a position opposite to the middle. Further, two keys 112E are formed on the outer surface of the core 112 at a position inclined by 45 degrees in the circumferential direction from the opening window 112B.

  Two locking projections 113A are formed at relative positions above and below the front outer surface of the pressing member 113, and the front ends of the locking projections 113A are inclined. Moreover, the opening window 113B is formed in the both sides of the pressing member 113, and the front part of the pressing member 113 is formed so that bending is possible. An outer flange 113C is formed at the rear portion of the pressing member 113, and two key grooves 113G are formed in the outer flange 113C so as to face each other. Further, the eraser 14 is fitted and attached to the rear inner hole 113E of the push member 113, and the knob 15 covering the eraser 14 is fitted to the rear outer surface 113F of the push member 113.

  The core 112 is inserted from the front of the sheath 111 with the key 112E of the core 112 aligned with the front keyway 111J of the sheath 111. Further, the pushing member 113 is inserted from the rear side of the sheath 111 with the key groove 113G of the pushing member 113 fitted to the rear key 111K of the sheath 111, and returned between the inner collar 111G of the sheath 111 and the outer collar 113C of the pushing member 113. The spring 16 is stretched. When the pressing member 113 is inserted as appropriate, the locking projection 113A of the pressing member 113 is locked and attached to the opening window 112B of the core 112. At this time, the key 112E of the core 112 is fitted to the front key groove 111J of the sheath 111 and the key groove 113G of the push member 113 is fitted to the rear key 111K of the sheath 111, so that the locking projection 113A of the push member 113 is It is securely fitted into the opening window 112B of the core 112. Therefore, the locking protrusion 113A of the push member 113 is normally locked to the locking step 112C of the core 112.

  FIG. 8 shows an embodiment of the present invention. The same members as those in FIG. In this embodiment, the outer sheath in FIG. 1 is eliminated, and the clip 110 is integrally formed with the sheath 211. This sheath 211 is detachably screwed to the body 107. All other members are the same as in FIG. 1 and have the same functions.

  The present invention is not limited to the above-described embodiment, and the sheath and the core, and the sheath and the pressing member are configured to be slidable in the longitudinal direction and non-rotatable by forming non-circular cross sections, respectively. If so, the core and the pressing member can be aligned.

  Further, the locking step formed in the core can be formed by a groove, an inner flange or the like in addition to the opening window. Further, it is possible to form a locking projection on the core and to configure a locking step on the push member.

  In order to receive the inertial force of the weight body at the front end of the core and to support the increased return spring force by the inner collar of the sheath when the pressing member is pressed, the core and the pressing member are disengaged. There is no need to form an opening window in the sheath in order to engage the push member, and the swing-out mechanical pencil expands the chuck by pushing the push member biased backward by the return spring. Applicable.

It is sectional drawing which shows Example 1 of this invention. Example 1 It is an expanded sectional view which shows the AA line of FIG. Example 1 It is an expanded sectional view which shows the BB line of FIG. Example 1 It is a principal part fragmentary sectional view which shows the engagement protrusion of the inner sheath in Example 1 of this invention. Example 1 It is sectional drawing which shows Example 2 of this invention. (Example 2) It is an expanded sectional view which shows the AA line of FIG. (Example 2) It is an expanded sectional view which shows the BB line of FIG. (Example 2) It is sectional drawing which shows Example 3 of this invention. (Example 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chuck 11 Sheath 11G Inner collar 11S of the sheath 11 Front key of the sheath 11 11I Rear key groove of the sheath 11 12 Core 12C Locking stage of the core 12 12D Key groove of the core 12 13 Pushing member 13A Pushing member 13 Locking projection 13D Key of pressing member 13 14 Eraser 16 Return spring 18 Core 20 Weight body 111 Sheath 111G Inner collar of sheath 111 111J Front keyway of sheath 111 111K Rear key of sheath 111 112 Core 112C Core 112 engagement Stop 112E Key 113 of the core 112 113 Pushing member 113A Locking projection 113G of the pushing member 113G Key groove 211 of the pushing member 113 Sheath

Claims (3)

In a swing-out mechanical pencil that advances the chuck by the inertial force of the weight body and feeds the lead, an inner collar is formed on the sheath, a locking projection is formed on one of the pressing member and the core, and the other is engaged with the other. A stop step is formed, and a return spring is stretched between the pushing member inserted from the rear of the sheath and the inner collar of the sheath, and a core is inserted from the front, and a locking projection is engaged with the locking step. The core and the pressing member are connected by joining, and the pressing member biased rearward in the longitudinal direction by the return spring is received by the core , and the weight body and the core can be brought into contact with each other. A swing-out mechanical pencil.   On the inner surface of the sheath, a front keyway or front key that is positioned forward of the inner collar and extending rearward in the longitudinal direction is formed, and a rear keyway or rear part that is positioned rearward of the inner collar and extends forward in the longitudinal direction The key or key groove formed on the core is engaged with the front key groove or front key of the sheath, and the key or key groove formed on the pressing member is used as the rear key groove or rear key of the sheath. 2. The swing-out mechanical pencil according to claim 1, wherein the front locking step and the locking projection are automatically aligned by engaging with each other.   3. The swing-out mechanical pencil according to claim 1, wherein an eraser is attached to the pressing member.

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