JP2557062Y2 - 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. (If you knock in the protruding state, your finger gets dirty, and there is a problem that the oil of your finger is transferred to the end surface of the eraser and the erasure is deteriorated.)

[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 mechanical pencil which is convenient for children of lower grades and for examinations.

[0004]

In order to achieve the above object, the mechanical pencil according to the present invention is provided with a lead case having a chuck fixed to the tip in a tip shaft so that the chuck can be moved in the axial direction. Attaching a chuck spring that rebounds with a weak force to the rear, a weight that can be fitted to the core case between the tip and the rear end of the core case and that can be shifted by its own weight is arranged, and an eraser at the rear end of the front shaft In the mechanical pencil to which the dispensing body is detachably mounted, the eraser dispensing body has a cap having a spiral groove in the inner hole, an inner cylinder having a slit and rotatably fastened in the cap inner hole, The inner cylinder is fixed so that it can only move in the axial direction through the spring of the return spring, and it is attached and detached to the rear end of the front shaft, and the eraser is fixed to the rear end with a projection on the side surface. Eraser holder, inner cylinder The protrusion is inserted into the slit and the spiral groove, and the shaft is swung by the inertia force of the weight by shaking the shaft, the core is fed out, and the eraser is erased from the rear end by rotating the cap with respect to the front shaft. Are configured to be able to come and go freely.

[0005]

1 and 2 show an embodiment of the present invention. First, a tip pipe 9 through which a wick can be inserted is fixed to the tip of the base 7, and a holding chuck 10 made of rubber or the like through which the wick is appropriately frictionally engaged and inserted is fixed to the end of the inner hole. Further, a screw portion (female screw) having a step portion 8 at the end is provided behind the inner hole of the base 7.

The front shaft 1 is provided with a shaft portion 2 having a screw portion 5 (male screw) at the tip of a cylindrical body, and the shaft portion 2 is provided with a hole having a front stage 6, and the hole is formed in the rear. Of the cylindrical body. Also, a step 3 is provided at the tip of the inner hole,
On the rear end inner wall of the inner hole portion, a shape is formed integrally with a later-described joining cylinder 34 and a projection 4 for retaining and locking in a rotational direction.

A chuck 14 is fitted into the hole of the shaft 2 of the front shaft by engaging the head with a fastener 15, and a core case 11 is inserted into an inner hole of the front shaft 1. The rear end of the chuck 14 is fixed to the front end of the chuck 11. At this time, the step portion 3 at the tip of the inner hole portion and the collar portion 1 provided substantially at the tip of the core case 11 are provided.
2, a chuck spring 16 is urged.
Note that the chuck spring 16 rebounds the chuck 14 rearward with an appropriate weak force. The lead case 11 is a cylindrical body provided with a lead storage portion through which a lead can be inserted into the chuck 14, and a flange portion 18 is formed at a rear end of the lead case 11 with a slit 19 at an appropriate position. A cushioning material 13 such as rubber is fixed to the outer periphery of the leading end of the lead case 11 in contact with the rear end of the flange portion 12, and a weight 17 is fitted further rearward by elastic deformation of the flange portion 18. The weight 17 can move axially between the cushioning material 13 and the flange portion 18 by its own weight.

In addition, a joint cylinder 34 of an eraser feeding body, which will be described later, is detachably fixed to the rear end hole of the front shaft 1. A groove 41 is formed in the side surface of the shaft portion 35 at the front of the joining cylinder 34, and the protrusion 41 of the rear end hole of the front shaft is elastically passed over and the two are prevented from coming off by appropriate force. Further, a shape is provided on a side surface of the joining cylinder 34 so as to be engaged with the rear end hole of the front shaft 1 and become integral with each other in the rotation direction. A slit 38 having a step portion 39 and an opening having a tapered portion 40 at an appropriate position from the rear end side is provided on a side surface of the shaft portion 36 behind the joining cylinder 34.

The eraser dispensing body is composed of a combination of a cap 20, an inner cylinder 24, an eraser holder 31, and the joining cylinder 34. The cap 20 is fitted on the outer periphery of the rear end of the front shaft 1 in the forward direction. A hole is provided, and a step 22 is formed at the rear end of the inner hole. A clip 23 is provided on the side surface, and a spiral groove 21 is formed on the inner surface. The inner cylinder 24 has a crown 28 at the rear end, which is in contact with the rear end surface of the cap 20, together with a hole through which the eraser 33 is inserted, and a long slit 25 is formed from substantially the center toward the crown. I have. A flange 27 is provided on the rear end side surface of the front shaft portion 26, a projection 29 is formed on the front side surface, and a boss portion 42 having the step portion 30 is further formed on the front side. .

[0010] The eraser dispensing body is configured such that an eraser holder 31 is elastically fitted from a slit 25 of an inner cylinder 24, a projection 32 provided on a side surface thereof is fitted into the slit, and the inner cylinder 24 is attached to a rear end of the cap 20. Then, the projection 32 is inserted into the spiral groove 21 while being fitted into the spiral groove 21, and the flange 27 is substantially brought into contact with the step 22 of the cap 20 by elastic deformation, so that the cap 20 is connected to the crown 28 and the joint cylinder flange 27. The inner cylinder 24 is rotatable with respect to the inner cylinder 24 and is prevented from falling off. An eraser 33 is fixed to the rear end of the eraser holder 31. A return spring 43 is attached between the flange portion 37 of the joining cylinder 34 and the step 22 of the cap 20, and the cap 20 and the inner cylinder 24 are elastically moved backward. The projection 2 of the inner cylinder 24
9 is fitted into the slit 38 of the joining cylinder 34 by utilizing the elastic deformation of the shaft portion 36, and the projection 29 is locked to the locking step portion 39 so as not to come off. Therefore, the inner cylinder 24 moves axially with respect to the joining cylinder 34, but is integrated in the rotation direction. The joining method between the inner cylinder and the joining cylinder is not limited. Further, the return spring 43 is urged with a stronger force than the chuck spring 16.

In this state, the eraser feeding body is detachably attached to the rear end hole of the front shaft 1. Also, at this time, the boss portion 42 is appropriately fitted in the rear end hole of the core case 11 while the step portion 30 ahead of the shaft portion 26 of the inner cylinder is substantially in contact with the rear end surface of the core case 11. When the rear end collides with the flange portion 18, the flange portion 18 is reduced in diameter and the weight 17 is prevented from coming off. When the cap 20 is rotated with respect to the front shaft 1, the eraser 33 is protruded from the rear end hole of the crown 28.

[0012]

First, in order to advance the lead, the weight 17 moves forward by grasping the front shaft 1 and swinging it forward in the axial direction.
The lead case 11 and the chuck 14 are moved forward by the inertia force of the lead to draw out the lead. When returning the core that has excessively protruded from the tip pipe 9, the cap 20 is advanced with respect to the tip shaft 1, and the tip of the core is pressed against the paper surface or the like, and the core returns into the tip pipe 9. When the cap 20 is rotated with respect to the front shaft 1, the eraser 33 is protruded from the rear end of the crown 28.

[0013]

[Effect 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 swinging the writing instrument forward in the axial direction. Therefore, it is necessary to knock the rear end every time the lead is extended as in the conventional case. There is no need to change the shaft and eliminate the hassle of having the eraser appear and disappear. Therefore, it is excellent as a mechanical pencil for lower grade children and examinees who frequently write and erase.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a blocking state of the joining cylinder and the inner cylinder of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front shaft 2 Shaft part 3 Step part 4 Projection 5 Screw part 6 Front part 7 Base 8 Step 9 Tip pipe 10 Holding chuck 11 Core case 12 Flange part 13 Buffer material 14 Chuck 15 Fastener 16 Chuck spring 17 Weight 18 Flange part DESCRIPTION OF SYMBOLS 19 Slippery 20 Cap 21 Spiral groove 22 Step 23 Clip 24 Inner cylinder 25 Slit 26 Shaft 27 Flange 28 Crown part 29 Projection 30 Step 31 Eraser holder 32 Projection 33 Eraser 34 Joint cylinder 35 Shaft 36 Shaft 37 Flange Part 38 slit 39 locking step part 40 taper part 41 groove 42 boss part 43 return spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A lead case having a chuck fixed to a tip thereof is accommodated in a front shaft so as to be axially movable, and a chuck spring for resiliently repelling the chuck with a small force is attached to a space between the tip and the rear end of the lead case. In a mechanical pencil with a weight that can be shifted by its own weight by being fitted to the core case and the eraser feeder is detachably attached to the rear end of the front shaft, the eraser feeder has an inner hole A cap provided with a spiral groove, an inner cylinder provided with a slit and rotatably fastened in the cap inner hole, and an inner cylinder fastened by a return spring to allow only axial movement and a front shaft A joint cylinder detachably attached to the rear end, and an eraser holder having a projection on the side surface and an eraser fixed to the rear end are formed by fitting the projection into the slit and the spiral groove in the inner cylinder, Inertia of the weight by shaking A mechanical pencil characterized in that the chuck is axially moved by a force to unwind the lead, and the cap is rotated with respect to the leading shaft so that the eraser can come and go from the rear end.