JP2557059Y2 - mechanical pencil - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a mechanical pencil for lower grade children and for examinations.

[0002]

2. Description of the Related Art Conventionally, a rear shaft is rotated with respect to a front shaft to feed a large-diameter eraser from a rear end of the rear shaft, and a rear shaft is knocked at a rear end of the front shaft to feed a core. Mechanical pencils are known. This object has the trouble of knocking the rear end frequently with the consumption of the core. In addition, there is an annoyance that the eraser projecting when knocking is stored in the rear shaft. (There is a problem that the finger gets dirty when knocked in the protruding state, or the oil of the finger is transferred to the end face of the eraser and the erasure is deteriorated.) Also, the core is automatically fed out by pressing the guide pipe at the tip. However, there is a problem that the structure is complicated and expensive. Further, although there is a product having a simplified structure, it is a disposable type and a structure in which replenishment of the core is impossible or difficult.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a low-cost mechanical pencil which is convenient for children of lower grades and for examinations.

[0004]

In order to achieve the above object, a mechanical pencil according to the present invention has a guide pipe appropriately projecting from the tip of a mouth plastic, a holding chuck for frictionally engaging a lead, and a mouth. A slider integrally provided with a piece that appropriately protrudes from a slit provided on the side of the plastic tip is provided so as to be able to move back and forth in the mouth plastic, and a chuck that grips the core via a ball is provided at the rear facing the slider. A spring is always provided to urge the slider forward and the chuck is always backward, and the core is inserted through the rear end hole of the front shaft to which the mouth plug is fixed at the front end, and a locking portion is provided at the rear end of the front shaft. When the eraser feeding body is fixed detachably in that place,
The partition provided in the inner hole of the eraser feeding body pushes the rear end of the core, the core is inserted to the tip of the guide pipe, and an appropriate amount of the core is pulled out of the guide pipe by one part back and forth movement, and the eraser feeding body has an inner hole An inner cylinder with a slit and a locking portion fixed to the front shaft is fixed to the cap with a spiral groove in a rotatable manner, and an eraser holder with a projection that fits into both the slit and the spiral groove is provided. The eraser is fixed and fitted into the inner cylinder, and the cap is rotated with respect to the front shaft so that the eraser comes out from the rear end.

[0005]

FIG. 1 shows an embodiment of the present invention. First,
A slider 5 is fitted in the inner hole of the mouth plug 1 so as to be movable back and forth. A guide pipe 6 through which a lead can be inserted is fixed to the front end of the slider 5, and a holding chuck 8 made of rubber or the like for allowing the lead to be appropriately frictionally engaged and inserted is fixed to the rear. A piece 7 is provided at an appropriate position on the circumference at substantially the center of the slider 5, and the piece 7 is elastically fitted into a slit 4 formed in a side surface of the mouth plastic 1 at the front side. The outer surface slightly protrudes from the side surface of the mouth plug 1.

At the rear of the holding chuck 8, a front end of a front shaft 14 is fixed to a rear end hole of the mouthpiece 1. The tip of the front shaft 14 has a shaft portion 16 having a tapered hole 15. A split chuck 9 is fitted in the tapered hole 15 in advance, and a concave portion 10 is appropriately formed on the outer periphery of a portion of the chuck 9 that grips the core 36, and the ball 12 is loosely fitted in the concave portion 10. The outer periphery of the ball 12 is in contact with the inner wall of the tapered hole 15. Further, a spring 13 is urged between the step 11 on the front side of the chuck 9 and the rear end of the piece 7 provided at the rear end of the guide pipe 6 of the slider 5 so that the front end of the piece 7 is In a state where the slider 5 is in contact with the step 3 at the rear end of the hole 2, the slider 5 is constantly pressed forward, so that the tip of the guide pipe 6 projects from the tip of the hole 2 of the mouth plug 1, and the chuck 9 is always rearward. It is configured to be able to move back and forth while pressed.

At the rear of the chuck 9, a cylindrical core guide 17 extends in an inner hole of the front shaft 14, and a rear end hole of the front shaft 14 is engaged with an eraser feeding member described later. A locking projection 18 for stopping is formed, and the lead 19 is inserted from the rear end hole of the lead guide 17 so as to pass the chuck 9 and the slider 5.

[0008] Further, the eraser dispensing body includes a cap 2
The cap 20 is formed by combining members of an inner cylinder 24 and an eraser holder 31, and the cap 20 is formed with an inner hole fitted on the outer periphery of the rear end of the front shaft 14 and a step 21 abutting on the rear end surface. It has a clip 23 on the outer periphery and a spiral groove 2 on the inner surface.
2 are formed. Also, the inner cylinder 24 has a crown portion 25 at the rear end, which is in contact with the rear end surface of the cap 20, together with a hole portion through which the eraser 33 is inserted, and a long slit 26 is formed substantially from the center toward the crown portion. I have. Further, a shaft portion 29 having a locking groove 30 which is engaged with the locking projection 18 of the front shaft 14 so as to stop the rotation and to prevent the shaft from coming off is provided in front of the shaft portion 2.
A partition portion 28 is formed in the inner hole 9, and a flange portion 27 is formed on the outer periphery of the rear end of the shaft portion 29. The eraser holder 31 has a hole with a bottom at the rear end for fixing the rear end of the eraser 33, and a projection 32 is provided on the outer peripheral portion at the front end.

The eraser holder 31 is elastically fitted from the slit 26 of the inner cylinder 24 to fit the projection 32 into the slit, and the inner cylinder 24 is inserted into the spiral groove 22 from the rear end of the cap 20. Insert while inserting,
The cap 20 is locked to the step 21 of the cap by elastic deformation, so that the cap 20 is rotatable with respect to the inner cylinder 24 between the crown 25 and the flange 27 and is prevented from falling off. An eraser 33 is fixed to the rear end of the eraser holder 31, and the shaft portion 29 of the inner cylinder is detachably fixed to the rear end hole of the front shaft 14. By the way, the locking projection 18 of the tip shaft 14 and the inner cylinder 24
The locking groove 30 provided in the shaft portion 29 can be replaced and provided. When the cap 20 is rotated with respect to the front shaft 14, the eraser 33 protrudes from the rear end hole of the crown 25.

[0010]

First, when the piece 7 is pulled rearward with a finger and released, the slider 5 moves back and forth, and the lead 19 protrudes from the tip of the guide pipe 6 by an appropriate amount, so that writing can be performed. When the piece 19 is drawn with a finger and released by writing, the slider 5 acting on the spring 13 moves forward, and the lead 36 is pulled out of the chuck 9 by the frictional engagement force of the holding chuck 8 each time. . Note that the chuck 9 opens the lead 19 with a small force in the forward direction, and holds the lead 19 with a sufficient force against the writing pressure in the rear. Further, if the rear end of the lead comes off the chuck 9 with the consumption of the lead 19, the feed is impossible. The new core is inserted into the core guide 17 with the shaft 29 of the eraser unreeling member removed from the front shaft 14, and the shaft 29 is attached to the front shaft 14.
Is fitted, the partitioning part 28 pushes the rear end of the core to discharge the remaining core from the tip of the guide pipe 6, and the tip of the new core projects from the tip of the guide pipe 6 as appropriate.
Further, when the cap 20 is rotated with respect to the front shaft 14, the eraser 33 protrudes and retracts from the rear end of the crown 25.

[0011]

[Effects of the Invention] The configuration and operation of the mechanical pencil of the present invention are as described above. The lead can be extended simply by pulling the tip lightly with the fingertip without changing the writing instrument, so that the troublesomeness of the prior art is eliminated. . In addition, a large-diameter, long eraser can be used immediately, and writing can be performed by inserting a core into the core guide portion and fixing the eraser feeder to the front shaft, so that it is easy to use. Further, since the structure is simple, it can be provided at low cost. Therefore, it is excellent as a mechanical pencil for lower grade children and examinees who frequently write and erase. For lower grades, the core diameter is about 1 mm and the core hardness is 2B ~
Around 4B is appropriate.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mechanical pencil according to an embodiment of the present invention.

[Explanation of symbols]

 1 port plastic 2 hole 3 step 4 slit 5 slider 6 guide pipe 7 piece 8 holding chuck 9 chuck 10 recess 11 step 12 ball 13 spring 14 front shaft 15 tapered hole 16 shaft 17 core guide 18 locking protrusion 19 Core 20 Cap 21 Step 22 Spiral Groove 23 Clip 24 Inner Tube 25 Crown 26 Slit 27 Flange 28 Partition 29 Shaft 30 Locking Groove 31 Eraser Holder 32 Projection 33 Eraser

Claims (1)

(57) [Scope of request for utility model registration] 1. A guide pipe 6 which appropriately protrudes from the tip of the mouth plastic 1, a holding chuck 8 which frictionally engages the core, and a piece 7 which appropriately protrudes from a slit 4 provided on a side surface of the front of the mouth plastic 1. A slider 5 integrally provided is provided so as to be able to move back and forth within the mouth puller 1, and a chuck 9 for gripping a core via a ball 12 is provided at the rear facing the slider 5, and a spring 13 always moves the slider 5 forward. The chuck 9 is always urged rearward, the core is inserted through the rear end hole of the front shaft 14 to which the mouth plug 1 is fixed at the front end, and a locking portion is provided at the rear end of the front shaft 14 to be attached and detached therefrom. When the eraser feeder is freely fixed, the partitioning portion 28 provided in the inner bore of the eraser feeder pushes the rear end of the lead, and the lead is inserted into the guide pipe 6.
Of the cap, which has a spiral groove 22 in the inner hole, is provided with a slit 26 and an inner cylinder 24 provided with the above-mentioned locking portion in a rotatable manner. An eraser holder 31 to which an eraser 33 is fixed is provided in the inner hole of the cylinder 24 so as to be movable back and forth.
2 into the slit 26 and the spiral groove 22 respectively.
A mechanical pencil characterized in that the eraser 33 is protruded and retracted from the rear end by rotating the cap 20 with respect to 4.