JPH0237583Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chuck body for a sharp pencil.

Conventionally, various types of chuck bodies for sharp pencils have been known which have a plurality of slits for imparting opening/closing ability to the chuck body and a lead holding portion capable of holding a lead. As shown in FIG. 1, the core insertion hole 102 through which the core passes is generally formed straight, and when performing the slitting operation on such a chuck body 101, Suriwari 10
There may be some burrs to a greater or lesser extent on the innermost end of 3. If the sharpening pencil is assembled with the burr remaining, problems such as poor centering will occur, and complicated work will be required to remove the burr. That is, such a chuck body is not suitable for mass production, and the manufacturing cost is also high.

Therefore, the present invention has developed a core insertion hole wall of the chuck body.
The above-mentioned problem is attempted to be solved by providing a concave zone corresponding to the rearmost part of the slot.

The present invention will be described in detail below based on examples.

Reference numeral 1 is a metal chuck body, and this chuck body 1 has a plurality of slits 2, 2 that provide opening/closing ability to the core, and a rough core holding surface 3 for clamping the inner core. It has a locking part 5 for connecting a lead holding part 4 and a lead storage tube (not shown). 6
is a core insertion hole through which the core passes, and this insertion hole 6
The wall is provided with a recessed zone 7 corresponding to the rearmost part of the slots 2, 2. In FIG. 2, the concave zone 7 is shown as having a screw-like groove, but as shown in FIG. 3, the concave zone 7 may be an annular concave portion with a slightly larger diameter than the core insertion hole 6. . That is, the concave zone 7 in the present invention refers to a zone having at least a concave portion extending toward the outer circumferential direction from the wall surface of the core insertion hole 6.

Next, the action will be briefly explained.

When performing the slitting operation, burrs generated at the rearmost part of the slitting are removed at the same time as the slitting operation by a recess zone formed on the wall of the core insertion hole.

As described above, in the present invention, a concave zone corresponding to the last end of the slit is provided on the wall of the core insertion hole of the chuck body, so that the burrs generated when the slit occurs can be easily removed. Therefore, it is possible to provide an inexpensive chuck body for a sharp pencil without requiring complicated work to remove burrs as in the past.

In the embodiment, a chuck body divided into two parts is shown, but the present invention can be applied to various chuck bodies such as a chuck body divided into three parts, and a ball chuck body. or,
In the present invention, some burrs are generated when forming the threaded grooves and annular recesses, but they are much smaller than the burrs created during slitting.
Problems such as poor centering do not occur. Further, in order to remove even such minute burrs, post-processing such as chemical polishing or etching may be performed after the slitting process.

[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 application example of the present invention, and FIG. 3 is a longitudinal sectional view of a modified example. 1...chuck body, 2...slit, 4...core holding part, 6...core insertion hole, 7...concave zone.

Claims (1)

[Scope of utility model registration request] A sharp pencil chuck body having a plurality of slots and a lead holding part, characterized in that a recessed zone corresponding to the rearmost part of the slot is provided on the wall of the lead insertion hole of the chuck body. Chart for use.