JP5365102B2 - mechanical pencil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein a weight body abuts on an outer collar of a lead tank in front and a front end of a knob in the rear every time a lead is delivered, resulting in making impact sounds of click-clack every time the weight body abuts on the outer collar and the knob and making a user feel disagreeable, particularly the sound is regarded as noise in the middle of a test in an elementary school, a junior high school, or the like to degrade the product value. <P>SOLUTION: This mechanical pencil has a lead delivery mechanism arranged in a shaft cylinder and operates the delivery mechanism by a cone arranged in the shaft cylinder. Cone receiving members are arranged in front and in the rear of the lead delivery mechanism, and each cone receiving member is provided with an elastic body. The cone is arranged between the elastic bodies provided respectively. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

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 present invention is a mechanical pencil in which a lead feeding mechanism is disposed in a shaft cylinder, and the feeding mechanism is operated by a weight body disposed in the shaft cylinder, and a weight receiving member is provided before and after the feeding mechanism. And an elastic body made of an O-ring is provided on the weight receiving member, a contact surface of the elastic body with the weight body is a curved surface, and the weight body is provided between the elastic bodies provided. The gist is that

The present invention is a mechanical pencil in which a lead feeding mechanism is disposed in a shaft cylinder, and the feeding mechanism is operated by a weight body disposed in the shaft cylinder, and a weight receiving member is provided before and after the feeding mechanism. And an elastic body made of an O-ring is provided on the weight receiving member, a contact surface of the elastic body with the weight body is a curved surface, and the weight body is provided between the elastic bodies provided. Therefore, it is possible to prevent as much as possible the sound generated during the lead feeding 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 in front of the lead tank 8 and grips and releases the lead, and is surrounded by a chuck body 9 in front of the chuck body 9. A chuck ring 10 that opens and closes 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 and arranged at the rear part of the rear shaft 2. It is comprised from the knock member 12 etc. which were made.
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. The lid body 14 is formed with two through-holes 16 that communicate with the space 15 and the outside. The front-end portion of the through-hole 16 has a thin wall so as to partially close the through-hole 16. A portion 17 is formed. Moreover, although the groove part 18 is formed in 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 metal coil spring surrounds the outer periphery of the core tank 8 and can move back and forth with respect to the core tank 8. In the weight body 20, an intermediate portion is a close contact portion 20a, and both ends are coarse winding portions 20b, but an end portion is a close seat portion 20c.
A receiving member 21 is fixed to the outer peripheral portion of the connecting portion between the lead tank 8 and the chuck body 9, and the receiving member 21 comes into contact with and separates from the seat portion 20 c of the weight body 20. Although an elastic body 22 such as an O-ring is fixed, the elastic body 22 may be formed integrally with the receiving member 21 by means such as two-color molding or insert molding, or the receiving member 21 itself. May be formed of an elastic body. On the other hand, a recess 12a is formed at the lower end of the inner surface of the knock member 12, and an elastic body 23 such as an O-ring that contacts and separates from the seat 20c of the weight body 20 is fixed to the recess 12a. However, it may be integrally formed by means such as two-color molding or insert molding. In this example, the concave portion 12a is reduced in diameter toward the lower side to prevent the elastic body 23 from falling off, but the convex portion is formed in a circumferential shape on the inner peripheral surface of the concave portion 12a. It may be possible to prevent dropping off. That is, the weight body 20 is disposed between the elastic body 22 and the elastic body 23, and moves between the elastic bodies 22 and 23.
The cross-sectional shape of the elastic bodies (O-rings) 22 and 23 is rectangular, while the cross-sectional shape of the weight body (coil spring) 20 is circular. That is, when the weight body 20 comes into contact with the elastic bodies 22 and 23, the line (seat portion 20c) comes into contact with the surface (the flat portion of the O-rings 22 and 23). Due to the contact between the line and the surface, there is an advantage that the line contact is made and the sound at the time of contact is smaller than that of the surface contact. However, the contact surface of the O-ring 23 (22) with the seat 20c may be a semicircular curved surface 23a (see FIG. 5). By bringing the weight 20 and the O-ring 23 into contact with each other by a line, the impact sound when they contact each other is further reduced. In the embodiment shown in FIG. 5, the weight body 29 is a metal cylindrical member. However, the weight member 29 may be an elastic cylindrical member using a resin material having a high specific gravity, or metal powder may be used as the resin material. A mixed cylindrical weight may be used.
The outer diameters of the O-rings 22 and 23 can come into contact with each other even when the weight body 20 is tilted back and forth. Therefore, the inner diameter of the opening of the recess 12a formed in the knock member 12 has an inner diameter that can enter the recess 12a even when the weight body 20 is inclined.
In this example, the elastic body 23 located above is disposed in the recess 12a formed below the knock member 12, but the receiving member is fixed to the inner surface of the shaft tube 1, and the elastic body 23 is attached to the receiving member. It may be arranged.

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 12b formed at the front end of the knock member 12 comes into contact with 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 seat portion 20 c formed in front of the weight body 20 comes into contact with the elastic body 22. Advancing force is applied to the receiving member 21 by the contact force, the chuck body 9 moves forward, and the lead is fed out. Here, since the front end portion (seat portion 20c) of the weight body 20 is in contact with the elastic body 22 having elasticity, an impact sound due to the contact force is prevented as much as possible. On the other hand, since the rear end portion (seat portion 20c) of the weight body 20 abuts against the elastic body 23 even when the weight body 20 is retracted by inertial force, the impact sound is reduced. In this way, the weight body 20 moves back and forth while repeating contact with the elastic bodies 22 and 23 arranged at the front and back, thereby extending the lead.
Further, in this embodiment, since the elastic body 23 is provided on the knock member 12 disposed in the shaft cylinder 1, even if the core feeding unit 7 and the shaft cylinder 1 are separated by repair or the like, Since the elastic body 23 remains in the shaft tube 1, the loss of the elastic body 23 is prevented.
Furthermore, since the weight body 20 of the present embodiment is a coil spring and the coarsely wound portion 20b is formed near the end of the coil spring, a cushioning action acts on the roughly wound portion 20b. Combined with the absorption of impact sound by the elastic bodies 22 and 23, the impact sound can be further reduced.
By pressing the knock member 12 via 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.

The external view which shows the 1st example of this invention. The longitudinal cross-sectional view of FIG. The principal part enlarged view of FIG. The AA line longitudinal cross-sectional view of FIG. The longitudinal cross-sectional view which shows a modification.

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 Filled body 20 Weight body 21 Receiving member 22 Elastic body 23 Elastic body 24 Repellent member 25 Eraser receiver 26 Eraser 27 Knock cover 28 Clip

Claims (3)

A mechanical pencil in which a lead feeding mechanism is arranged in the shaft cylinder and the feeding mechanism is operated by a weight body arranged in the shaft cylinder, and a weight receiving member is arranged before and after the feeding mechanism, Each of the weight receiving members is provided with an elastic body made of an O-ring , the contact surface of the elastic body with the weight body is a curved surface, and the weight body is disposed between the elastic bodies provided. Mechanical pencil characterized by 2. The mechanical pencil according to claim 1, wherein the weight receiving member is provided on a shaft cylinder. 3. The mechanical pencil according to claim 1, wherein the weight body is a coil spring, the vicinity of both ends of the coil spring is roughly wound, and the intermediate portion is closely wound.

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