JPH0621748Y2 - Notch type sharp pencil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a knock-type sharpener in which an eraser or a second writing instrument is attached to the rear end of a lead case which is connected to the back of a chuck and transmits a knocking motion to the chuck. Regarding pencils.

(Prior Art and Problems Thereof) In this type of conventional mechanical pencil, an eraser or a second
When using the writing instrument of, the core case is urged rearward so that the lead case will not be knocked out and the lead will not be drawn out, and that it will not wobble when using the eraser or the second writing instrument. It is necessary to make the knock spring moderately strong. Conversely, if the knock spring is too strong, a large amount of force will be required when knocking in order to extend the core, and the usability will deteriorate. It was extremely difficult to set. Therefore, several knock-type mechanical pencils have been proposed that are provided with a mechanism that prevents the lead case from advancing when using an eraser or a second writing instrument, but all of them have complicated structures, lack reliability, and are expensive. However, it has not been commercialized.

(Object of the invention) Therefore, the present invention prevents the advance of the lead case when the eraser or the second writing instrument is used without making the knock spring too strong to prevent the lead-out of the lead and the eraser or the second writing instrument. It can improve usability,
An object of the present invention is to provide a novel knock-type mechanical pencil that has sufficient reliability, has a simple structure, and reduces costs.

(Means for Achieving the Purpose) The knock type mechanical pencil of the present invention devised to achieve the above object is an eraser or a second eraser at the rear end of the lead case which is connected to the rear of the chuck and transmits the knocking motion to the chuck. In a knock-type mechanical pencil to which the writing instrument of is attached, a locking step is provided on the outer surface near the rear end of the lead case, and the side surface near the rear end of the shaft cylinder is elastically deformable inward of the shaft cylinder. In the elastically modified state, a stopper piece is provided to prevent the forward movement of the lead case by contacting the leading edge with the locking step of the lead case.

(Embodiment) The illustrated embodiment of the present invention is capable of moving a required stroke in the axial direction while being connected to the rear of a chuck (not shown) and being urged rearward by a knock spring (not shown). A fitting portion 3 of an eraser 2 is provided in a rear end inner hole portion of a core case 1 mounted in the shaft cylinder, and a collar 4 is circumferentially provided on an outer surface portion near the rear end of the core case 1. A knock cover 5 for covering the eraser 2 is attached to the outer peripheral portion of the rear end of the core case 1 in a more rearward position with its front end opening edge abutting the rear side surface of the collar 4, and the front side surface of the collar 4 has an acute angle. Concave recessed step 1
1 is provided, and on the other hand, U-shaped slits 7 are formed at two positions on the side surface portion 180 degrees apart in the circumferential direction in the vicinity of the rear end of the synthetic resin cylinder 6, and the tip edge is surrounded by the slits 7. Is formed as a stopper piece 10 by providing a convex portion 9 on the outer surface portion near the tip edge of the elastic plate 8 formed at an acute angle, and the stopper piece 10 is elastically deformed when the rear end portion of the barrel 6 is gripped by hand. Then, the shaft cylinder 6 is bent inward, and its sharp edge is engaged with the locking step portion 11 of the core case 1 described above.

(Operation) The operation will be described based on the above embodiment. When the eraser 2 is used, the knock cover 5 is removed and the barrel 6 is reversed to change the grip position to the rear end of the barrel. Due to the gripping pressure, the stopper piece 10 is elastically deformed inward of the barrel 6, and the sharp tip edge of the stopper piece 10 is engaged with the locking step portion 11 of the core case 1. Therefore, the rubbing pressure of the eraser 2 is applied to the shaft cylinder 6 via the collar 4 of the core case 1 and the stopper piece 10, and is not applied to the core case 1.
Never move forward. Therefore, the core is not extended, and the eraser 2 is also supported without wobbling during use. Therefore, it is not necessary to strengthen the knock spring. Incidentally, the convex portion 9 provided on the stopper piece 10 is for facilitating the pressing of the stopper piece 10, and the locking step portion 11 of the core case 1 and the tip edge of the stopper piece 10 are formed into an acute angle. The purpose is to make it difficult to disengage the engaged state and to reduce the pressing force applied to the stopper piece 10. Stopper piece 10 after using eraser 2
The stopper piece 10 is restored when the hand is removed from the core case 1
The engagement with the locking step portion 11 is released, and the lead case 1 can be moved forward again, that is, the lead can be fed out again.

Further, when the second writing instrument is attached to the rear end of the lead case 1 instead of the eraser 2, the operation does not change.

(Effects of the Invention) As described above, the knock type mechanical pencil of the present invention does not apply the rubbing pressure or the writing pressure to the core case when using the eraser or the second writing instrument, and the shaft cylinder is inserted through the stopper piece. This prevents the lead case from advancing, so the lead does not come out when using the eraser or the second writing instrument, so there is no need to strengthen the knock spring, so when using the original mechanical pencil, The ease of feeding out improves usability, and at the same time, eraser or second
Even when using the writing instrument, since it is firmly supported by the stopper piece without wobbling, it has the effect of improving usability. Further, the structure is simpler than that of the conventional example, and an inexpensive product can be provided.

[Brief description of drawings]

FIG. 1 shows an embodiment of the invention. FIG. 1 is a side view showing a partially cut state in which an eraser is used, FIG. 2 is a side view showing a partially cut state in a normal state, and FIG. 3 is a rear end. FIG. 1 ... Core case, 2 ... Eraser, 3 ... Eraser fitting part, 4 ...
Tsuba, 5 ... Knock cover, 6 ... Shaft cylinder, 7 ... Slit, 8 ...
Elastic plate, 9 ... convex portion, 10 ... stopper piece, 11 ... locking step portion.

Claims (1)

[Scope of utility model registration request] Claims: 1. A knock type mechanical pencil in which an eraser or a second writing instrument is attached to the rear end of a lead case which is connected to the back of the chuck and transmits a knocking motion to the chuck. While providing a locking step,
The side surface near the rear end of the shaft cylinder can be elastically deformed inward of the shaft cylinder, and in the elastically deformed state, the leading edge abuts the locking step of the core case to prevent the core case from moving forward. Knock-type mechanical pencil, which is equipped with a stopper piece.