JPH07237397A - Letting-out type rubber erasing device - Google Patents

Abstract

PURPOSE:To simplify assembling procedure and reduce production cost by a method wherein a projection is formed so as to have an incline at the rear end of the slit of an inner tube and a stepped part at its front end and a stepped part, the rear part of which is made slightly narrower, is formed in the elastic piece of a rubber eraser holder. CONSTITUTION:By fittingly installing a rubber eraser holder 18, to which a rubber eraser 23 is fixed, from the rear end of a slit 12 in the bore part of an inner tube 11 and fitting an elastic piece 20 having a projection 19, the rear part of which is made slightly thin, in the slit 20 under the condition that a projected part 24 is elastically expanded and, at the same time, by inserting the inner tube 11 from the front end of a cap 4, a flange part 15 is fitted by being elastically deformed to the groove 7 of the cap. Further, at this time, under the condition that the front end of the rubber eraser holder 18 is abutted against the stepped part 16 at the front end of the slit 12 of the inner tube 11, a projection 19 is fitted to a spiral groove 5. Thus, the inner tube 11 is rotatably locked to the cap 4. When the rubber eraser holder 18 reaches the regression limit of the cap 4, the stepped part of the elastic piece 20 abuts against the stepped part of the projected part 24 at the rear end of the inner tube 11, resulting in being brought under the state that the elastic piece 2 is properly projected from the rear end of the cap 4.

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 so-called feeding type eraser device which is arranged at the rear end of a writing instrument and is adapted to feed out an eraser by rotating.

[0002]

2. Description of the Related Art Conventionally, there is known a mechanical pencil in which a cap is rotated with respect to a front shaft to extend a large-diameter eraser from the rear end, and a rear end is knocked against the front shaft to extend a lead. In the conventional case, a large-diameter crown portion is formed at the rear end of the inner cylinder having the slit, and an eraser holder having a protrusion on the side surface is fitted into the inner cylinder from the slit. The cap has a spiral groove in the inner hole from the rear end, and a step portion is provided in the front end inner hole. From the rear end of the cap, while rotating the inner cylinder appropriately, insert the protrusion of the eraser holder into the spiral groove and insert it, and with the front end of the crown part in contact with the rear end of the cap, the shaft in front of the inner cylinder The elastic protrusion provided on the side surface of the cap is locked to the step of the inner hole of the cap, or the ring is press-fitted to the shaft and locked to the step, and the cap is sandwiched between the crown and the step. Wear it to prevent the inner cylinder from freely rotating with respect to the cap. Also, the eraser is fixed to the rear end of the eraser holder.At this time, since the eraser holder is located almost at the rear end of the spiral groove, the cap is rotated with respect to the inner cylinder and the eraser is placed inside the cap. Need to be immersed in. Therefore, there is a problem that assembly takes too much time. Further, there is a problem that the process becomes complicated when assembling with an automatic machine. Also, because the rear end of the elastic piece contacts the rear end of the slit (front end of the crown) at the retracted end of the eraser holder, the inconvenience of not knowing the end state of the eraser and the remaining part of the eraser when the eraser is barely used There are problems that are difficult to remove.

[0003]

SUMMARY OF THE INVENTION The first object of the present invention is to solve the problem of the assemblability of the conventional example.
The second purpose is that when the eraser holder reaches the retracted limit of the cap as the eraser is consumed, the elastic piece that holds the eraser protrudes from the rear end of the cap to inform the limit of use of the eraser and retain the eraser. To make it easier to attach a new eraser.

[0004]

SUMMARY OF THE INVENTION The feeding type eraser device of the present invention devised to achieve the above object has a spiral groove in the inner hole of the cap, and the eraser appears and disappears at the rear end of the spiral groove. , A groove is formed at the front end of the spiral groove,
A slit that opens to the rear end is inserted into the inner hole of the cap, and an inner cylinder having a shaft portion in the front is inserted, and the rear end of the inner cylinder is located almost to the rear end of the eraser retracted hole, The cylinder is rotatably attached to the cap, and the inner cylinder has an elastic piece that holds the eraser in the inner hole.The eraser holder has a protrusion on the side of the front cylinder. Possible,
The protrusion and the elastic piece are respectively fitted in the slits, and the protrusion is further fitted in the spiral groove, and the shaft portion of the inner cylinder is integrally joined with the front shaft in the rotation direction, and when the cap is rotated with respect to the front shaft, the eraser is erased. In a feed-out type eraser device in which the holder is retracted so that the eraser can be retracted from the rear end of the cap, a protrusion having an inclined surface at the rear end of the slit of the inner cylinder and a stepped portion at the front end is formed. , Furthermore, the elastic piece of the eraser holder is provided with a step and the rear is formed to have a slightly narrow width, and the step of the elastic piece comes into contact with the step of the projection due to the elastic deformation of the projection, and the eraser holder is prevented from coming off. The narrow width portion of the elastic piece is appropriately projected from the rear end of the cap when the eraser holder is retracted.

[0005]

1 to 5 show an embodiment of the present invention. First, the feed-out type eraser device includes a cap 4,
The inner cylinder 11 and the eraser holder 18 are combined to form a cap 4. The cap 4 has an inner hole 6 and a concave groove 7 which are fitted on the outer periphery of the rear end of the front shaft 1, and a spiral groove behind the concave groove 7. 5 is formed, and an eraser retracting hole 10 is provided at the rear end of the spiral groove 5. Further, a clip 9 is provided on the outer peripheral side surface of the cap 4 by being connected with a clip base portion 8.

The inner cylinder 11 has a hole 12 through which an eraser 23 is inserted, and a slit 12 which is long from approximately the center toward the rear end 13.
Has been drilled. Further, a projection 24 having an inclined surface 25 at the rear end of the slit 12 and a step portion 26 at the front end thereof is formed. Further, in the front, there is a shaft portion 14 which is integrally engaged with the rear end hole of the front shaft 1 in the rotational direction, and the outer peripheral portion of the lead case 3 of the mechanical pencil is appropriately fixed to the inner hole of the shaft portion 14. Further, a partition portion 17 that comes into contact with the rear end of the lead case 3 is provided. Further, a collar portion 15 that is elastically fitted into the concave groove 7 of the cap is provided on the rear outer periphery of the shaft portion 14.

Further, the eraser holder 18 is formed with a pair of elastic pieces 20 sandwiching the rear end of the eraser 23 at the rear,
The elastic piece 20 is provided with a step portion 20a so that the rear side is slightly narrow. Further, a locking projection 21 is formed on the inner surface of the narrow portion so as to bite into the outer surface of the eraser 23.
Further, a pair of protrusions 19 is provided on the side surface of the front cylindrical portion 22 coaxially with the elastic piece 20. (See Figure 4)

An eraser holder 18 is fitted into the inner hole of the inner cylinder 11 from the rear end of the slit 12, and the projection 24 is elastically expanded to fit the projection 19 and the elastic piece 20 into the slit. At the same time, the eraser 23 is fixed to the rear end of the eraser holder 18, the inner cylinder 11 is inserted from the front end of the cap 4, and the collar portion 15 is elastically deformed so that the concave groove 7 of the cap 7 is formed.
Fit in. At this time, the protrusion 19 is fitted into the spiral groove 5 in a state where the front end of the eraser holder 18 is in contact with the step portion 16 at the front end of the slit of the inner cylinder 11. (To be exact, when the inner cylinder is fixed to the front shaft, the cap is slightly rotated with respect to the front shaft so that the projection and the spiral groove come into contact with each other.)
Is rotatable with respect to the cap 4 and is prevented from coming off.
The shaft portion 14 of No. 1 is prevented from rotating in the rear end hole of the front shaft 1 and is fixed to the core case 3.

By the way, a writing element of a mechanical pencil is provided in front of the tip shaft 1 so as to extend the lead in conjunction with the forward and backward movement of the lead case 3. The structure thereof is not the gist of the present invention, so the description thereof will be omitted.
Further, in the present embodiment, the feeding-type eraser device provided at the rear end of the mechanical pencil writing tool is shown, but a ballpoint pen in which the tip of the writing comes out from the tip of the shaft due to the knock at the rear end is also applied as the writing tool. At that time, instead of the eraser, a solid correction agent or the like that allows the ballpoint pen ink to be erased is attached. In the case of a rubber latex type erasable ballpoint pen, an eraser is attached.

By the way, in the embodiment of the present invention, the flange portion 15 of the inner cylinder is engaged with the concave groove 7 of the cap by elastic deformation, and the inner cylinder 11 is rotatably supported with respect to the cap 4. However, it is also possible to fix the ring member to the inner hole of the inner cylinder or the cap to form the same structure.

FIG. 5 shows another form of the eraser holder. The eraser holder 30 is provided with a pair of protrusions 31 on the side surface of the cylindrical portion 34 coaxially with the elastic piece 32. Further, the tubular portion 34 has a split portion 36 at substantially the center in the axial direction, and has a split shape joined by a hinge portion 35 on the front surface. Further, the elastic piece 32 has a step portion 32a and a front portion thereof having a slightly narrow width. A locking projection 33 is formed inside the narrow portion. The reason why it is divided into two is that resin molding of the member is facilitated. It is also possible to fix the two-split members by providing locking portions at their essential parts without sticking to the hinge joining.

[0012]

First, when the cap 4 is rotated to the left or right with respect to the front shaft 1, the eraser 23 comes in and out from the rear end hole of the cap 4.
If the rear end of the cap 4 is knocked with the eraser 23 retracted, the lead can be drawn out. When the eraser is exhausted and the eraser holder 18 reaches the retreat limit of the cap 4, the step portion 20a of the elastic piece 20 has the protrusion 24 at the rear end of the inner cylinder.
The stepped portion 26 of the elastic member 20 contacts the elastic piece 20 as shown in FIG.
The (narrow width portion) appropriately protrudes from the rear end of the cap 4 to notify the end state of the eraser, and the eraser 2
The holding of 3 (sandwiching of the eraser by the locking projection 21) can be released, and a new eraser is replaced.

[0013]

The construction and operation of the feed-out type eraser device of the present invention are as described above, the members can be assembled and attached from one direction, and the assembly procedure is simplified, so that the cost can be reduced. . In particular, when the assembly is performed by an automatic machine, the process is simplified, which is further effective. or,
The elastic piece protrudes properly from the rear end of the cap when the eraser holder is retracted, so you can see the limit of use of the eraser, and
The eraser is released from the clamped state, making it easier to replace a new eraser.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part showing a feed-out type eraser device according to an embodiment of the present invention, in which an appropriate amount of eraser is projected.

FIG. 2 is a vertical cross-sectional view of a main part showing a state when an eraser is replaced.

FIG. 3 is a view showing a slit and a rear end projection of an inner cylinder used in this embodiment.

FIG. 4 is a perspective view of an eraser holder used in this embodiment.

FIG. 5 is a perspective view showing another example of an eraser holder.

[Explanation of symbols]

 1 Front Axis 2 Inner Hole 3 Core Case 4 Cap 5 Spiral Groove 6 Inner Hole 7 Recessed Groove 8 Clip Base 9 Clip 10 Hole 11 Inner Tube 12 Slit 13 Rear End 14 Shaft 15 Collar 16 Step 17 Partition 18 Eraser Holder 19 Protrusion 20 Elastic Piece 20a Step 21 Locking Protrusion 22 Cylinder 23 Eraser 24 Protrusion 25 Sloping Surface 26 Step 30 Eraser Holder 31 Protrusion 32 Elastic Piece 32a Step 33 Locking Protrusion 34 Cylindrical 35 35 Hinge 36 Department

Claims (1)

[Claims] 1. A spiral groove is provided in an inner hole of a cap arranged at a rear end of a front shaft having a writing portion on the front side, and an eraser retracting hole opened at a rear end of the spiral groove is provided at a front end of the spiral groove. A recessed groove is formed in the inside of the cap, and a slit that opens to the rear end is inserted into the inner hole of the cap, and an inner cylinder that has a shaft portion in the front is inserted, and the rear end of the inner cylinder is approximately behind the hole where the eraser appears. Positioned to the end, the inner cylinder is rotatably attached to the cap, and the inner hole of the inner cylinder has an elastic piece that holds the eraser in the rear. The eraser holder that you can move back and forth, the protrusion and the elastic piece are respectively inserted in the slit, the protrusion is further inserted in the spiral groove, the shaft part of the inner cylinder is integrally joined with the front shaft in the rotation direction, When the cap is rotated, the eraser holder retracts so that the eraser can appear and disappear from the rear end of the cap. In the feed-out type eraser device, the feed-out type eraser device is such that the rear end of the slit of the inner cylinder is formed with a protrusion having an inclined surface and a step portion at the front end, and the elastic piece of the eraser holder is further formed. By providing a step and forming the rear part to a slightly narrow width, the eraser holder is prevented from coming off by the step of the elastic piece coming into contact with the step of the protrusion due to the elastic deformation of the protrusion, and at the backward limit of the eraser holder, A retractable eraser device, characterized in that the narrow width portion of the elastic piece is configured to appropriately protrude from the rear end of the cap.