JPS6229271Y2 - - Google Patents

Description

[Detailed description of the invention] An example of the invention is as shown in FIG.
a chuck body 5 which is biased toward the rear by the
The present invention relates to an improvement of a chuck device for a sharp pencil comprising a rolling element 6, for example a sphere, disposed between the chuck body 5 and the tapered inner surface 3.

In this type of chuck device, the core can be held by the wedge action of the tapered inner surface 3 and the rolling elements 6, 6, and the wedge action is eliminated by the advancement of the chuck member 5 against the chuck spring 4. Along with this, the above-mentioned clamping of the core is released due to the restoring elasticity of the chuck body 5 itself. However, this structure has rolling elements 6,
Since the chuck spring 4 is connected by point contact with the chuck body 6 and the force of the chuck spring 4, which is the source of the pressure contact force, is not particularly strong, the shaft center of the chuck body 5 tends to swing.

The purpose of the present invention is to eliminate this drawback. In the present invention, as shown in an embodiment in FIG. 2, a regulating surface 2 parallel to the axis is provided in the vicinity of the tapered inner surface 3. At the same time, this purpose is achieved by arranging a plurality of other rolling elements 8 at each end of the split 7 of the chuck body 5 so as to be in contact with the regulating surface 2.

The rolling elements 6 and 8 may be cylindrical bodies instead of spheres, and the regulating surface 2 may have a rectangular cylindrical inner surface instead of a cylindrical inner surface.

In the illustrated example, the chuck body 5 is divided into two parts, and the number of rolling elements 6 and 8 is two each.
are almost 90° out of phase. This rolling element 8,
8 is in contact with the regulating surface 2 parallel to the axis, and when the chuck body 5 moves forward or backward, it moves back and forth while maintaining the positional relationship between the chuck body 5 and the regulating surface 2, so that the chuck body 5 It is clear from FIG. 3 that there is no problem in expanding and contracting the diameter. Further, the same holds true even if the above-mentioned regulating surface 2 is a rectangular cylindrical inner surface. In the figure, 9 is the rolling element 6, 8
It is a concave seat.

According to the above-described configuration of the present invention, the chuck body 5
The chuck body 5 expands and contracts in diameter by the back and forth movement of the plurality of rolling elements 6 in contact with the tapered inner surface 3, while the position of the chuck body 5 and the regulating surface 2 is maintained without being affected by the expansion and diameter contraction of the chuck body 5. The plurality of rolling elements 8 that move back and forth while maintaining the relationship prevent the axial center from wobbling laterally. Moreover, since the rolling elements 8 are mounted at each end of the split 7 of the chuck body 5, there is no problem in expanding and contracting the diameter of the chuck body 5, that is, in clamping and releasing the core, as described above.

In the above-mentioned embodiment, an example was shown in which the cylindrical inner surface, which is the regulating surface 2, and the tapered inner surface 3 were formed in the action tube 1, which is separate from the sharp pencil main body. The present invention can be implemented in a configuration in which the cylindrical inner surface, which is the regulating surface 2, is integrally formed with the sharpening pencil body, and only in a configuration in which only the tapered inner surface 3 is formed separately.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure of the chuck device of a sharp pencil, Fig. 2 is a sectional view of the chuck device of the present invention, and Figs. 3 and 4 are the - line in Fig. 2.
- is a sectional view taken along the line in the direction of the arrow. 1... Working pipe, 2... Regulatory surface, 3... Tapered inner surface. 4... Spring for chuck, 5... Chuck body, 6... Rolling element, 7... Split, 8... Rolling element.

Claims (1)

[Scope of utility model registration request] A tapered inner surface 3 whose diameter gradually decreases, a chuck body 5 urged rearward by a chuck spring 4, and a rolling element 6 disposed between the chuck body 5 and the tapered inner surface 3. In this sharp pencil chuck device, a regulating surface 2 parallel to the axis is provided near the tapered inner surface 3, and other plurality of regulating surfaces 2 are provided at each end of the split 7 of the chuck body 5 so as to be in contact with the regulating surface 2. A chuck device for a sharp pencil, characterized in that a rolling element 8 is arranged.