JPH0413198Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a knock-type sharp pencil, and more particularly to a knock-type sharp pencil that is easy to assemble by attaching a lead feeding mechanism to the tip. It is something.

(Prior art) As disclosed in Japanese Utility Model Application Publication No. 151192/1983, a knock-type sharp pencil that is easy to assemble by attaching a lead feeding mechanism to the tip has a mechanism between the chuck ring and the spring. A cylindrical sleeve with an inner flange interposed therein is attached to the connecting part at the rear end of the cap by screwing, press-fitting, engaging, etc.
As disclosed in the above publication, an engaging protrusion is provided on the outer surface of the joint interposed between the chuck ring and the spring, and the engaging protrusion is inserted into the L-shaped notch of the cap and rotated to engage. What has been done is known. However, in the former case, screwing as an attachment means tends to be expensive to manufacture and is subject to wall thickness limitations, and press-fitting and engagement are used in cases where the core breaks inside the cap. This poses a problem in use because it cannot be removed, and while the latter has the advantage of being simple in structure and easy to remove, the latter method has the advantage that the engaging protrusion is engaged with the L-shaped notch in the cap. There is a problem in that the sliding distance required for the assembly causes play after assembly, causing a defect in the centering length.

(Purpose of the invention) This invention was created in view of the problems mentioned above.
To provide a knock-type sharp pencil which has a simple structure and is easy to assemble, has a removable lead feeding mechanism, and has good precision without causing looseness even after assembly.

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

1 to 3 show a first embodiment of the present invention, and in FIG. 1, reference numeral 1 is
It has a lead protection tube 2 at its tip, a lead holder 3 behind it that holds the lead with slight elasticity, and an inner stepped part 4 that restricts the forward movement of a chuck ring 8, which will be described later. The tip 1 is detachably attached to the shaft tube 5 with a threaded portion formed on the outer surface. Reference numeral A denotes a lead feeding mechanism, and the lead feeding mechanism A includes an expandable chuck 7 that can hold the lead, a chuck ring 8 that is fitted onto the chuck 7, and a chuck ring 8 that is connected to the chuck 7 and attached to the rear with a spring 9. It is composed of a core tank 10 which is energized, and a cylindrical sleeve 11 whose inner flange is interposed between a spring 9 and a chuck ring 8. In the normal state shown in Figure 1, chuck 7 is connected to spring 9.
is urged backward and tightened by the chuck ring 8, thereby holding the core L between them. Sleeve 11
As shown in FIG. 2, the elastic piece 12 has an elastic piece 12 at its rear end that slopes forward, and has a tip in the middle part as shown in FIG. It has an engagement protrusion 15 that can be engaged with an engagement hole 14 formed in the rear part of the metal piece 1, and is attached to the tip piece 1 by engaging the engagement protrusion 15 with the hole 14. ing.

4 and 5 show a second embodiment of the present invention, in which the sleeve 16 has an engaging protrusion 17 having a sharply tapered side wall on its outer circumferential surface, and the rear end thereof The sleeve 16 has a similar elastic portion 18 that slopes forward, and the sleeve 16 has an engaging protrusion 17 inserted from the rear into an engaging hole 21 having a guide slit 20 formed at the rear of the tip 19. It is attached to the tip 19 by engaging with the tip.

(Operation) The operation of the present invention will be explained below with reference to a first embodiment.

The lead feeding mechanism A is attached to the tip 1 by inserting the sleeve 11 from behind the tip 1 and engaging the engagement protrusion 15 with the engagement hole 14. 15 is engaged with the engagement hole 14, the elastic portion 13 of the sleeve 11 is attached to the rear end surface of the tip 1.
is pressed and deformed, that is, generates an elastic force that urges the sleeve 11 backward with respect to the tip 1, so that the sleeve 11 does not play even if there is a gap necessary for engagement. It is engaged with the tip 1 with the elastic force. Moreover, the removal of the lead feeding mechanism A from the tip 1 is also possible using the engaging protrusion 15.
This can be easily done by pressing inward to release the engagement from the engagement hole 14. The second embodiment also has the same effect as described above.

(Effects) As is clear from the above description, in the present invention, in the knock-type sharp pencil assembled by attaching the sleeve of the lead feeding mechanism to the tip which is removably screwed onto the tip of the barrel, The sleeve includes an engagement protrusion that engages with an engagement hole provided at the rear of the tip, and an elastic portion that comes into pressure contact with the tip and presses the sleeve backward when the sleeve is engaged with the tip. is formed, and the sleeve is removably attached to the tip, so there is no centering length defect due to play in the gap required for engagement, and the accuracy is good, and the sleeve is removably attached to the tip. It is possible to provide an unprecedented and excellent knock-type sharp pencil whose lead feeding mechanism can be easily removed from the tip even if breakage occurs.

In each of the illustrated embodiments, the engaging protrusion, the engaging hole, and the elastic part are provided at only one location, but the number may be increased as appropriate, and the engaging hole may have a conventional L-shape. The shape, etc. can be changed in various ways without changing the gist of the present invention, such as using a notch.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a longitudinal cross-sectional view of the first embodiment, FIG. 2 is an external perspective view of the sleeve shown in FIG. 1, and FIG. FIG. 4 is an external perspective view of a sleeve showing a second embodiment of the present invention, and FIG. 5 is an external view of the same metal. A... Core feeding mechanism, 1, 19... Lead deposit, 6
...Shaft tube, 11, 16...Sleeve, 13, 18
...Elastic part, 14, 21...Engagement hole, 15, 17
...Engaging protrusion.

Claims (1)

[Scope of utility model registration request] In a knock-type sharp pencil assembled by attaching a sleeve in the lead feeding mechanism to a tip that is removably screwed onto the tip of the barrel, the sleeve has an engagement hole provided at the rear of the tip. an engaging protrusion that engages with the tip; and an elastic portion that comes into pressure contact with the tip and presses the sleeve backward when the sleeve is engaged with the tip, and the sleeve is removably attached to the tip. This is a notsuku style pencil pencil.