JP5251294B2 - mechanical pencil - Google Patents

Description

  The present invention relates to a mechanical pencil in which a lead feeding mechanism is arranged in a shaft cylinder, and the feeding mechanism is operated by a weight body arranged in the shaft cylinder.

Conventionally, a mechanical part consisting of a chuck, chuck ring, chuck spring, lead tank, and heavy body is slidably mounted in the mechanical pencil body, and chucked by the inertial force of the heavy body generated by shaking the mechanical pencil body. A mechanical pencil is known that moves the lead forward to advance the core.
No. 1-35991

  However, in the conventional technique, each time the lead is fed out, the weight body comes into contact with the outer casing of the front lead tank and the front end of the rear knob. As a result, every time the weight body comes into contact with the outer casing or the knob, an impact sound such as “tick” is generated, which sometimes makes people feel uncomfortable. In particular, it was perceived as noise during tests at elementary schools and junior high schools, and its value as a product was also reduced.

The invention, together with placing the feeding mechanism of the core in the barrel, a mechanical pencil which actuated by weight body disposed in the barrel the feeding mechanism, and the weight element to the magnet, the weight The first gist is that magnets repelling the weight body are arranged in front and rear of the body, and the weight body moves between the magnets, and a core feeding mechanism is arranged in the shaft cylinder, A mechanical pencil in which a feeding mechanism is actuated by a weight body disposed in a shaft cylinder, and an elastic body member that can be expanded and contracted is interposed between the front and back of the weight body, and the weight body is moved while expanding and contracting the elastic body. that none to move back and forth as the second aspect.

The invention, together with placing the feeding mechanism of the core in the barrel, a mechanical pencil which actuated by weight body disposed in the barrel the feeding mechanism, and the weight element to the magnet, the weight The first gist is that magnets repelling the weight body are arranged in front and rear of the body, and the weight body moves between the magnets, and a core feeding mechanism is arranged in the shaft cylinder, A mechanical pencil in which a feeding mechanism is actuated by a weight body disposed in a shaft cylinder, and an elastic body member that can be expanded and contracted is interposed between the front and back of the weight body, and the weight body is moved while expanding and contracting the elastic body. Since the second gist is to move back and forth, it is possible to prevent as much as possible the sound generated during the lead-out operation, thereby improving the value of the product.

A specific configuration will be described below with reference to FIGS. The shaft body 1 includes a rear shaft 2, a front shaft 3 fixed to the front portion of the rear shaft 2, and a front member 4 detachably fixed to the front portion of the front shaft 3 by means such as screwing. It is configured. Reference numerals 5 and 6 are joint members interposed in a connecting portion between the rear shaft 2 and the front shaft 3, and the thickness of the rear shaft 2 due to a sudden increase in diameter is optimized. Inside the shaft cylinder 1, a lead feeding unit 7 for feeding the lead is disposed so as to be movable back and forth. The lead feeding unit 7 includes a lead tank 8 that stores a plurality of leads, a chuck body 9 that is fixed to the front of the lead tank 8 and grips and releases the lead, and is surrounded by a chuck in front of the chuck body 9. A chuck ring 10 that opens and closes the body 9, a coil spring 11 that urges the core tank 8 and the chuck body 9 backward, and a rear end of the core tank 8 are detachably attached to the rear portion of the rear shaft 2. It is comprised from the knock member 12 etc. which were arrange | positioned.
The outer periphery of the front shaft 3 is covered with a gripping portion 13 made of a bag-like permeable resin by integral molding or the like, and the rear end portion of the bag-like gripping portion 13 is impermeable resin. A ring-shaped lid body 14 made of is welded all around by the laser light irradiation. That is, the space 15 of the bag-shaped gripping portion 13 is sealed by the lid body 14. In the lid body 14, through holes 16 communicating with the space 15 and the outside are formed at two opposite positions, and a thin portion 17 is formed at the front end portion of the through hole 16 so as to close the through hole 16. Is formed. Moreover, although the groove part 18 whose cross section is circular arc shape is formed in the circular arc shape in the rear-end surface of the cover body 14, you may form in the periphery shape. The groove portion 18 communicates with the through hole 16. The thin-walled portion 17 formed in the through-hole 16 can be torn with a sharp tip such as an injection needle, but after being torn, it can be restored even though there is a break. It has become a thing. That is, when no external force is applied, the through hole 16 can be sealed.
An enclosure 19 such as a fine solid, elastic resin, or viscous material is enclosed in the space 15 of the grip 13.

A weight body 20 made of a magnet surrounds the outer peripheral portion of the core tank 8 and can move back and forth with respect to the core tank 8. The weight body 20 includes a cylindrical body 20a and magnets 20b fixed to both ends of the cylindrical body 20a. A receiving member 21 is fixed to the outer peripheral portion of the connecting portion between the core tank 8 and the chuck body 9, and a magnet 22 to which a magnetic force repelling the weight body 20 is applied to the receiving member 21. Is fixed. On the other hand, a magnet 23 repelling the weight body 20 is also fixed to the lower end of the knock member 12. That is, the weight body 20 is disposed between the magnet 22 and the magnet 23 and moves between the magnets 22 and 23. Further, the weight body 20 is almost the same as that of the lead tank 8 in a normal state, that is, in a state where no external force is applied to the mechanical pencil (shaft body 1) by the repulsive force from the magnets 22 and 23 arranged at the front and rear. Standing still in the center.
Reference numeral 24 is an elastic member such as a coil spring that urges the knock member 12 rearward. Further, by urging the knock member 12 backward, it is possible to prevent the eraser receiver 25 and the knock cover 27 from rattling, and to prevent the eraser 26 from being retracted with a light force when the eraser 26 is used. Yes. Further, a gap is formed between the rear end portion of the lead tank 8 and the knock member 12. In addition to preventing unintentional lead-out of the lead when an unexpected pressing force is applied to the knocking member 12, unnecessary lead-out operation when using the eraser 26 is prevented. That is, the elastic force of the chuck spring 11 is weakened in order to facilitate the feeding of the lead by shaking. Therefore, the elastic force of the coil spring 24 prevents the unnecessary lead feeding operation by the knock cover 27.
Further, an eraser receiver 25 is fixed behind the knock member 12, and a knock cover 27 is detachably attached to the eraser receiver 25 so as to cover the eraser 26 and the eraser 26. Reference numeral 28 denotes a clip attached to the shaft tube 1, but it may be formed integrally with the shaft tube 1. The knock member 12 is urged rearward by a coil spring 24, but the flange portion 12a formed at the front end of the knock member 12 abuts on the insertion tube portion 28a of the clip 28. The falling off of the rear end opening of the rear shaft 2 is prevented. Further, an elastically deformable protrusion 25a is formed at the intermediate portion of the eraser receiver 25 and is slidably fitted into the vertical groove 28b formed in the insertion tube portion 28a. This fitting prevents the eraser receiver 25 from falling off the rear shaft 2.

The operation will be described. When the mechanical pencil (shaft cylinder 1) is shaken in the vertical direction, the weight body 20 moves back and forth by inertial force. When the weight body 20 moves forward, the weight body 20 approaches the magnet 22, but since a repulsive action is imparted to the magnet 22, as a result, a forward force is imparted to the magnet 22, and the chuck The body 9 moves forward and the lead is extended. However, since the weight body 20 and the magnet 22 repel each other, and as the weight body 20 approaches the magnet 22, the repulsive force increases, so that the weight body 20 does not contact the magnet 22. . On the other hand, even when the weight body 20 is retracted by an inertial force, it does not come into contact with the magnet 23 due to a repulsive action with the magnet 23. Therefore, the weight body 20 can move back and forth without coming into contact with the magnets 22 and 23 arranged at the front and rear, and the lead is fed out.
Even when writing is in progress, when the shaft cylinder 1 is not shaken (the core is not extended), the weight body 20 applies a repulsive force to the magnet 22 and the magnet 23, that is, from the front and rear directions. Therefore, not only the movement in the front-rear direction but also the movement in the radial direction is prevented as much as possible, thereby preventing an unpleasant sound that the weight 20 contacts the core tank 8 and the like.
Of course, when the knock member 12 is pressed through the knock cover 27, the lead tank 8 moves forward and the chuck body 9 also moves forward to feed the lead.

The kind of resin and / or elastic resin used for the transmissive resin material (gripping part 13) is not particularly limited as long as it can transmit laser light as a heating source at a predetermined transmittance or higher. As the resin, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyethylene resin (PE), polypropylene resin (PP), polystyrene resin (PS), acrylonitrile styrene resin (AS), acrylonitrile styrene butadiene resin (ABS), Methacrylic resin (PMMA), polyacetal resin (POM), polyamide resin (PA) such as nylon 6 resin (PA6) and nylon 66 resin (PA66), polycarbonate resin (PC), polyethylene terephthalate resin (PET), polybutylene terephthalate (PBT), ethylene tetrafluoride resin (PTFE), elastic resins include acrylic resin, silicone resin, fluorine resin, vinyl chloride, urethane resin, polyurethane resin, polyethylene resin, elastomer gel, Reethylene gel, urethane rubber, ethylene acrylic rubber, epichlorohydrin rubber, acrylic rubber, ethylene propylene rubber, chloroprene rubber, natural rubber, isoprene rubber, chlorinated polyethylene, nitrile rubber, styrene elastomer, olefin elastomer, ester elastomer, urethane Although an elastomer etc. are mentioned, if a shape can be maintained, it will not specifically limit. These resins and / or elastic resins may be one kind or a mixture of two or more kinds.

  The hardness of the elastic resin may be appropriately selected within a hardness range of 0 to 90 degrees for Shore A or 0 to 90 degrees for Asker C, and is not particularly limited. However, an elastic resin of 60 degrees or less on Shore A and 80 degrees or more on Asker C becomes hard and less sticky or swells on the surface. Therefore, it is an elastic resin of 60 degrees or less on Shore A and 80 degrees or less on Asker C. It is desirable.

  The type of resin and / or elastic resin used for the non-permeable resin material (lid 14) is not particularly limited as long as it can absorb laser light as a heating source without transmitting it. That is, in this example, the gripping part 13 and the lid body 14 are joined by laser welding. As the resin, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyethylene resin (PE), polypropylene resin (PP), polystyrene resin (PS), acrylonitrile styrene resin (AS), acrylonitrile styrene butadiene resin (ABS), Methacrylic resin (PMMA), polyacetal resin (POM), polyamide resin (PA) such as nylon 6 resin (PA6) and nylon 66 resin (PA66), polycarbonate resin (PC), polyethylene terephthalate resin (PET), polybutylene terephthalate (PBT), ethylene tetrafluoride resin (PTFE), elastic resins include acrylic resin, silicone resin, fluorine resin, vinyl chloride, urethane resin, polyurethane resin, polyethylene resin, elastomer gel, Reethylene gel, urethane rubber, ethylene acrylic rubber, epichlorohydrin rubber, acrylic rubber, ethylene propylene rubber, chloroprene rubber, natural rubber, isoprene rubber, chlorinated polyethylene, nitrile rubber, styrene elastomer, olefin elastomer, ester elastomer, urethane Examples thereof include elastomers, and examples thereof include those in which a predetermined colorant such as carbon black, dye, pigment, or the like, which has sufficient absorbability for laser light, is mixed in a resin and / or elastic resin. In addition, an organic coloring material may be used as long as it exhibits sufficient absorbability with respect to laser light. Examples of such a coloring material include copper phthalodianine pigments.

  The combination of the resin used for the permeable resin material (gripping portion 13) and the resin used for the non-permeable resin material (lid 14) is a combination of compatible materials. Resins such as combinations of nylon 6 and nylon 66, combinations of PET and PC, combinations of PC and PBT, and combinations of styrene elastomer and polypropylene resin (PP) in addition to combinations of resins of the same type And a combination of elastic resins, and a combination of elastic resins such as a combination of an olefin elastomer and urethane rubber, but any combination of compatible resins may be used.

A second example will be described with reference to FIG. In this example, instead of the magnets 22 and 23, elastic members 30 and 31 such as coil springs and rubber-like elastic bodies are interposed before and after a weight body 29. More specifically, a coil spring 30 is interposed between the front end portion of the weight body 29 and the receiving member 21, and on the other hand, between the rear end portion of the weight body 29 and the front end portion of the knock member 12. Also, a coil spring 31 is interposed. That is, the weight 29 is stationary in a state where it floats at the substantially central portion of the core tank 8 as in the weight 20 of the first example.
Here, if the shaft cylinder 1 is shaken in the front-rear direction, the weight body 29 moves back and forth while compressing and extending the respective coil springs 30 and 31 by inertial force. When the weight body 29 moves forward, the coil spring 30 is compressed and the chuck body 9 moves forward so that the lead is fed out. At this time, the contact between the coil spring 31 located behind and the rear end portion of the weight body 29 may be released, but the front end portion of the coil spring 31 and the rear end portion of the weight body 29 are fixed. The coil spring 31 may be extended by the above. Of course, the rear end of the coil spring 31 and the knock member 12 need to be fixed. In addition, when the weight body 29 moves backward, the coil spring 31 located at the rear is compressed.

The external view which shows the 1st example of this invention. The longitudinal cross-sectional view of FIG. FIG. 2 is a longitudinal sectional view taken along line AA in FIG. 1. The longitudinal cross-sectional view which shows a 2nd example.

DESCRIPTION OF SYMBOLS 1 axis | shaft main body 2 rear axis | shaft 3 front axis | shaft 4 tip member 5 joint member 6 joint member 7 core feeding unit 8 core tank 9 chuck body 10 chuck ring 11 coil spring 12 knock member 13 gripping part 14 lid body 15 space part 16 through-hole 17 Thin portion 18 Groove portion 19 Enclosed material 20 Weight body 21 Receiving member 22 Magnet 23 Magnet 24 Repellent member 25 Eraser receiver 26 Eraser 27 Knock cover 28 Clip 29 Weight body 30 Coil spring 31 Coil spring

Claims (2)

A mechanical pencil in which a lead feeding mechanism is arranged in a shaft cylinder and the feeding mechanism is operated by a weight body arranged in the shaft cylinder, and the weight body is used as a magnet, and the front of the weight body. A mechanical pencil, characterized in that a magnet that repels the weight is arranged behind, and the weight moves between the magnets. A mechanical pencil in which a lead feeding mechanism is arranged in the shaft cylinder and the feeding mechanism is actuated by a weight body arranged in the shaft cylinder, and a retractable elastic member is interposed between the front and rear of the weight body. A mechanical pencil characterized in that the weight body moves back and forth while expanding and contracting the elastic member .

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