JP2004249624A - Shaking-out type mechanical pencil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaking-out type mechanical pencil, in which an impact force developed through the abutting of a weight 12 against a connector 2 can be absorbed by elastic pieces 2B having a large deflecting amount and the inertial force of the weight 12 can be surely transmitted to a chuck 1. <P>SOLUTION: In the shaking-out type mechanical pencil, in which the chuck 1 is advanced by means of the inertial force of the weight 12 developed through the shaking of a barrel 7 so as to deliver a lead 10, the elastic pieces 2B extending circumferentially from a basic part 2A is formed in a synthetic resin connector 2 connecting with the chuck 1. Further, projecting parts 2C radially projecting rearwards are formed at the tip parts of the elastic pieces 2B. A lead tank 3 is mounted to this connector 2 so constituted the weight 12 loosely fitted on the outside of the lead tank 3 as to make abutting against the projecting parts 2C of the connector 2 in order to transmit the inertial force of the weight 12 to the chuck 1 under the condition that the impact given by the inertial force is absorbed by the elastic pieces 2B. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing mechanical pencil that advances a chuck by an inertial force of a weight body to feed out a lead.
[0002]
[Prior art]
When the impact of a heavy object is directly transmitted to the chuck, the conventional swing-out mechanical pencil absorbs the impact of the heavy object because the chuck is in contact with the step portion of the base with a strong force and breaks the chuck. For this purpose, rubber was fitted to the core tank and the weight was in contact with the rubber. (See Patent Document 1)
Alternatively, a flexible protrusion is formed on the core tank, and the weight body is in contact with the flexible protrusion. (See Patent Document 2)
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 54-130535 [Patent Document 2]
Japanese Utility Model Laid-Open No. 2-58983 [0004]
[Problems to be solved by the invention]
However, in the conventional swing-out mechanical pencil described above, when the rubber is externally fitted to the lead tank, the number of parts increases, the number of assembly steps increases, and the cost increases. In the case where the protruding portion was formed, the amount of bending was small, and the impact force of the heavy body could not be absorbed sufficiently.
[0005]
An object of the present invention is to provide a swing-out mechanical pencil that solves the above-mentioned problems.
[0006]
[Means for Solving the Problems]
The present invention relates to a swing-out mechanical pencil in which a chuck is advanced by an inertial force of a weight body generated by shaking a barrel to feed out a lead, and a synthetic resin connector connected to the chuck extends in a circumferential direction from a base. Along with forming the elastic piece, a protrusion projecting rearward in the longitudinal direction is formed at the tip of the elastic piece, and a lead tank is attached to the connector. The elastic member of the connector transmits the inertial force of the weight body to the chuck while absorbing the impact by the elastic piece of the connector.
[0007]
【Example】
Hereinafter, the swing type mechanical pencil of the present invention will be described with reference to FIG. In addition, let the left side of FIG. 1 be front, and let the right side be back. First, a polyacetal connector 2 is press-fitted and fixed to a rear portion of a metal chuck 1 made of brass or the like. As shown in FIG. 2 and FIG. 3, the connector 2 protrudes to both sides at a substantially middle portion and cuts up and down to form a base 2A. Two elastic pieces 2B are formed extending from the base 2A in the circumferential direction by approximately 45 degrees, and a protrusion 2C protruding rearward in the longitudinal direction is formed at the tip of each elastic piece 2B. Further, two outer flanges 2D whose front surfaces are vertical and whose rear surfaces are inclined are formed at the rear part of the connector 2. The rear part of the connector 2 is press-fitted and fixed to the front part of a core tank 3 made of a polypropylene pipe material. Since the connector 2 made of polyacetal is harder than the core tank 3 made of polypropylene, the connector 2 can be firmly connected to the core tank 3. Further, a tightening ring 4 is externally fitted to the head 1A of the chuck 1, and a spring 6 is stretched between the connector 5 for receiving the tightening ring 4 and the connector 2.
[0008]
The front hole 7A of the shaft cylinder 7 is configured so that the core tank 3 and the connector 2 can be inserted therethrough. Further, a rubber grip 8 for preventing slippage is fitted to the front narrow diameter portion 7B of the shaft cylinder 7. The core tank 3 is inserted from the front of the shaft cylinder 7, and the connecting tool 5 is sandwiched between the front end of the shaft cylinder 7 and the inner step 9A of the base 9 screwed to the front end of the shaft cylinder 7. The rubber grip 8 is held between the rear end of the base 9 and the outer step 7C of the shaft cylinder 7. The base 9 has a built-in lead holder 11 made of an elastic body such as rubber which holds the lead 10 with an appropriate force.
[0009]
The weight body 12 is formed of a metal cylinder, and the weight body 12 is slidably housed in an inner hole 7D opened from the rear end of the shaft cylinder 7 and having a larger diameter than the front hole 7A. . The core tank 3 is inserted into the through hole 12A of the weight body 12.
[0010]
In the swing-out mechanical pencil described above, the inertia force acts on the weight body 12 by shaking the barrel 7, and the weight body 12 comes into contact with the protrusion 2C formed on the elastic piece 2B of the connector 2. Then, the connector 2 moves forward while absorbing the impact force when the weight body 12 comes into contact with the elastic piece 2B by bending. In addition, since the elastic piece 2B of the connector 2 is formed to extend in the circumferential direction from the base 2A, the elastic piece 2B can be formed long, and a large amount of bending can be taken, so that the impact force of the weight body 12 is sufficiently absorbed. be able to. Accordingly, the chuck 1 and the lead tank 3 are moved forward together with the connector 2 and the lead 10 is fed out by a predetermined amount. At this time, the forward movement of the chuck 1 is stopped by abutting on the step 9B of the base 9, but the impact force of the weight body 12 is absorbed by the elastic piece 2B of the connector 2, so that the chuck 1 is strongly driven by the base. There is no danger of colliding with the step 9B of the ninth. Further, there is no need to worry about the connector 2 coming off the core tank 3 due to an impact when the weight body 12 comes into contact with the connector 2.
[0011]
The weight body 12 is not limited to a metal cylinder, but may be a metal wire wound in a coil shape and a spring portion formed at the front thereof.
[0012]
【The invention's effect】
The swing type mechanical pencil of the present invention described above forms an elastic piece sufficiently extended in the circumferential direction from the base on the connector, and the protrusion formed on the elastic piece contacts the weight, so that the weight is connected to the connector. In addition to being able to absorb the impact force at the time of contact with the elastic piece having a large deflection amount, the inertial force of the weight body can be transmitted to the chuck without fail.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a swing-out mechanical pencil of the present invention.
FIG. 2 is an enlarged front view showing the connector of the present invention.
FIG. 3 is an enlarged sectional view taken along line AA of FIG. 2;
[Explanation of symbols]
Reference Signs List 1 chuck 2 connector 2A base 2B of connector 2 elastic piece 2C of connector 2 protrusion 3 of connector 2 core tank 7 shaft cylinder 10 core 12 weight body

Claims (2)

An elastic piece that extends in the circumferential direction from the base to the synthetic resin connector connected to the chuck is formed on a swing type mechanical pencil that advances the chuck by the inertia of the weight body generated by shaking the barrel and pulls out the lead. At the same time, a protrusion protruding rearward in the longitudinal direction is formed at the tip of the elastic piece, and a lead tank is attached to the connector, and the weight body loosely fitted to the outside of the lead tank comes into contact with the protrusion of the connector. A mechanical pencil that is constructed so as to be able to transmit the inertial force of the weight body to the chuck while absorbing the impact by the elastic piece of the connector. A base is formed by projecting on both sides and cutting the top and bottom at the approximate middle part of the connector, extending approximately 45 degrees in the circumferential direction from this base to form two elastic pieces, and a longitudinal end is formed at the tip of each elastic piece. 2. A swing type mechanical pencil according to claim 1, wherein a projecting portion projecting rearward in the direction is formed.

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