JPS5820392Y2 - mechanical pencil lead tank - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lead tank for a knock-type mechanical pencil.

In the lead case of a knock-type mechanical pencil, a knock cover is removably fitted to the rear open end of a lead tank connected to a chuck.

This knock cover needs to be designed so that it does not come off from the wick tank when it is turned downward, and so that it can be easily removed from the wick tank when supplying the wick to the wick tank.

For this reason, in the past, either the knock cover was punched out or the wick tank was punched out.

However, precision is required for punching out the punch, and it is difficult to regulate the force for attachment and detachment when fitting the knock cover.

Also, when punching out the knock cover side, it cannot be used for machined metal items.

In order to overcome this drawback, a knock cover 2 has been conventionally provided with a slit and a restraining piece 3 bent inward, as shown in FIG. 1.

According to this structure, the force for attaching and detaching the knock cover 2 to the core tank 1 can be easily regulated.

However, if the lead tank 1 is made of thin metal and the holder 6 holding the eraser 5 is fitted to its open end, the difference between the outer diameter of the lead tank 1 and the outer diameter of the eraser holder 6 is small. Therefore, when the knock cover 2 is removed, the holding piece 3 comes into pressure contact with the eraser holder 6 due to its elastic restoring force as shown by the chain line, and there is a risk that the eraser holder 6 and the eraser 5 may be brought together due to frictional resistance. Ta.

This drawback also applies when the punch is extended to the knock cover side as described above.

The purpose of the present invention is to reduce the variation in the force for fitting and disengaging the knock cover when it is fitted with the knock cover without requiring high precision, and to form the knock cover by any means such as metal cutting, in addition to forming the knock cover by pressing. It can also be used even if at least the fitting part of the lead tank into which the knock cover fits is made of thin metal, and when an eraser is fitted to the open end of this lead tank, the knock cover can be used. To provide a lead tank for a mechanical pencil which can prevent an eraser from being taken along with the lead tank when it is removed from the lead tank.

In order to achieve the above object, the present invention provides a lead tank in which an eraser holder holding an eraser is fitted on the inside, and a knock cover covers the eraser and eraser holder and is fitted on the outside. The fitting part into which the knock cover fits is formed of thin metal, and the fitting part is cut and raised to prevent the knock cover from coming off in the axial direction. .

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Figures 2 to 4, 11 is a cylindrical core tank made of thin metal such as stainless steel, one end of which is connected directly to the chuck with or without a joint, and the other end is connected directly to the chuck through a joint or without a joint. The ends are open.

An eraser holder 16 holding an eraser 15 is fitted inside this opening.

Thus, this lead tank 11 is slidably housed within the barrel of the knock-type mechanical pencil.

Reference numeral 12 denotes a knock cover that covers the eraser 15 and the eraser holder 16 and is removably fitted to the rear of the lead tank 11, and its inner diameter is naturally larger than the outer diameter of the lead tank 11.

Reference numeral 13 denotes a piece for preventing the knock cover 12 from coming off, which is provided at the rear portion of the core tank 11 where the knock cover 12 is fitted, and is formed with a U-shaped cut in the axial direction from the rear end of the opening of the core tank 11. However, the tongue piece formed by cutting and splitting is raised so as to protrude outward to be larger than the inner diameter of the knock cover 12.

The shape of the removal prevention piece 13 can be formed into any shape other than the U-shape as shown in the figure, and the number thereof can be one on the outside of the rear part of the core tank 11 where the knock cover 12 fits, or It is also optional to provide a plurality of them.

In addition, 14 is a stopper of the knock cover 12 provided at the rear of the core tank 11, and is formed by being bulged into an annular shape by pressing.

Therefore, as shown in FIG. 4, a holder 16 holding an eraser 15 is fitted to the open end of the lead tank 11, and
Even if the difference between the outer diameter of the eraser holder 16 and the outer diameter of the eraser holder 16 is small, the knock cover 12 has no inward protrusion, so there is no risk of contacting the eraser holder 16 when removing the knock cover 12, and the eraser There is no risk of bringing 15 with you.

As is clear from the above description, according to the present invention, at least the fitting portion of the core tank into which the knock cover fits is formed of thin metal, and the knock cover is prevented from coming off in the axial direction at this fitting portion. The holding piece is cut and raised to make the span longer.

Therefore, compared to the conventional punching method, high precision is not required, and it is possible to reduce variations in the force of attachment and detachment when fitting the knock cover, and furthermore, the means for forming the knock cover is limited to presses. First, it can be formed by any method such as metal cutting or by any material.

In addition, even if a holder holding an eraser is fitted to the open end of the lead tank, and the lead tank is thin and there is little difference between its outer diameter and the outer diameter of the eraser holder, it can be held in place as described above. By providing the piece on the lead tank side, the knock cover can eliminate any inward protrusions, so when removing the knock cover, it does not come into contact with the eraser holder and prevents the eraser from being brought along with it. There are advantages such as being able to

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the fitted state of a conventional wick tank and knock cover, Figs. 2 to 4 show an embodiment of the present invention, Fig. 2 is a side view, and Fig. 3 is a side view. FIG. 2 is a cross-sectional view taken along the line A-A, and FIG. 4 is a cross-sectional view showing a state in which a knock cover is fitted. 11... Core tank, 12... Knock cover, 13... Pull-out prevention piece.

Claims (1)

[Scope of utility model registration request] In a lead tank in which an eraser holder holding an eraser is fitted on the inside, and a knock cover is fitted on the outside by covering the eraser and eraser holder, at least a fitting part into which the knock cover fits is provided. Shaped by thin metal,
This mechanical pencil lead tank is characterized by having a holding piece cut and raised in the fitting part to prevent the knock cover from coming off in the axial direction.