JPH0215667Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a knock-type mechanical pencil, and more particularly to a knot-type mechanical pencil that prevents the lead storage tube installed in the barrel of the pencil from swinging laterally.

As shown in FIG. 1, the lock-type sharp pencil has a core storage tube 104 inside a barrel 101 that is biased backward by an elastic member 103 in conjunction with a chuck 102, such as a collection chuck or a ball chuck, that can hold the lead. be provided with the ability to reciprocate in the direction,
At the rear of this lead storage tube 104 is an eraser 105 and a lock cap 10 that covers the eraser 105.
6 is detachably attached.

In such a knock-type sharp pencil, a certain amount of gap 107 is created between the outer surface of the lead storage tube 104 and the inner surface of the barrel tube 101 to be advantageous for assembly work, and this gap 107 is created as much as possible in the design.
Although it is possible to make the number 7 smaller, there is a limit when considering variations in component dimensional accuracy and problems with the knock operation. During normal writing and when the knob is operated, the existence of the gap 107 mentioned above does not have much of an effect, but when the knob cap 106 is removed from the lead storage tube 104 and the eraser 105 is used, the lead storage tube 104 may sway horizontally, resulting in an emergency. There was a problem that it was difficult to erase.

As disclosed in Japanese Utility Model Application No. 57-201387, a structure that can be adopted to solve the above-mentioned problem is that a locking part is provided in the core storage tube, and an elastic O-ring is inserted into this locking part. A device in which the core is brought into local contact with the inner surface of the shaft cylinder is known, but although it can eliminate the lateral vibration of the core storage tube, the contact pressure of the elastic O-ring due to variations in component precision may cause the notch pressure when the core is fed out. There was still room for improvement as it was expected that the weight would be extremely heavy.

This idea was created in view of the problems mentioned above.
To provide a knock-type sharp pencil which does not cause any hindrance to the operation of the knob when feeding out the lead and can prevent the lateral vibration of a lead storage tube.

The present invention will be described in detail below based on embodiments shown in the accompanying drawings.

In FIG. 2, reference numeral 1 is a lock-type mechanical pencil, and inside a barrel 2 made of metal, resin, etc., there is a collection chuck for holding a lead;
A core storage tube 5 is provided so as to be able to reciprocate in the axial direction in conjunction with a chuck 3 such as a ball chuck and urged rearward by an elastic member 4 such as a spring. Reference numeral 6 denotes a tip body fixed to the tip portion of the shaft cylinder 2 by appropriate means such as screwing, and the internal structure is outside the scope of the present invention, so a description thereof will be omitted. Core storage tube 5
A locking portion 8 formed from two protrusions 7, 7 is provided at the rear of the holder, and an elastic body 9 made of an elastic member such as an O-ring or a C-ring is attached to the locking portion 8. It is located. As the locking portion 8, a groove 10 as shown in FIG. 3 may be employed.
Reference numeral 11 denotes an annular body fixed to the rear part of the shaft cylinder 2. This annular body 11 is provided with an inclined portion 12, and the inclined portion 12 is brought into contact with the above-mentioned elastic body 9 to be in a steady position. Although it is conceivable that this degree of contact may change due to variations in the dimensional accuracy of the parts, this degree of change can be sufficiently absorbed by the elasticity of the elastic body 9.
13 is an eraser, 14 is a knock cap,
Each is detachably attached to the rear part of the core storage tube 5.

As described above, in the present invention, an elastic body is placed at the rear of the core storage tube, and this elastic body is brought into contact with the inclined part of the ring body fixed to the rear of the shaft cylinder at a steady position, so that the lock cap is pressed. In some cases, the lead can be fed out without any problems as the elastic body separates from the inclined part.Also, when removing the notch cap from the lead storage tube and using the eraser,
The core storage tube does not sway laterally due to contact between the elastic body and the inclined portion, and can perform suitable erasing.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional example, FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view of main parts showing another embodiment. 2... Shaft tube, 3... Chack, 4... Resilient member, 5... Core storage tube, 8... Locking part, 9... Elastic body, 11... Annular body, 12... Inclined part, 13... Eraser, 14... Note cap.

Claims (1)

[Scope of utility model registration request] A lead storage tube is provided inside the barrel so that it can reciprocate in the axial direction in conjunction with a chuck that can hold a lead and is urged backward by an elastic member, and an eraser and a cap are removably attached to the rear of the lead storage tube. In the knob-type sharp pencil, an elastic body is arranged at the locking part at the rear of the lead storage tube, and the elastic body is brought into contact at a steady position with the inclined part of the ring body fixed to the rear of the barrel. Notsuku style mechanical pencil.