JPH03112583A - Scissors - Google Patents

Abstract

PURPOSE:To manufacture scissors of good cutting performance in a large quantity by forming each of the contact areas around the pivot holes at the intersecting portions of a pair of scissor blades in a complete flat surface. CONSTITUTION:The contact area 1b, 1b' around the pivot holes 1a, 1a' at the intersecting portions of paired scissor blades 1, 1' are formed in complete flat surfaces. While the shape and surface roughness of the contact area 1b (1b') affects the contact resistance and the opening and closing actions of the scissors, its shape is preferably a circle, a semicircle, an ellipse or an arc, and its surface roughness is preferably in the range of 5 - 10 micrometers Rmax. To form the contact areas 1b and 1b' in a complete plane, material pieces are manufactured within the blanking area tolerances so that the edge contact portion and the contact area are kept parallel to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to scissors in which the contact area of the intersection of the scissors is formed into a completely flat surface.

[Conventional technology]

Scissors are conventionally manufactured by grinding hardened steel, and the contact surfaces of the two blades at the intersection of the scissors are usually not always in the same shape (and the area around the shaft support hole is similar to the blade). Because it was processed with a grinder, it had a concave, arc-shaped concave surface.

However, the polishing of scissor blades has traditionally been done by hand, and as it is based on the experience of professional craftsmen, there are individual differences, and even products made by the same person may have variations in shape and dimensions. There was a problem that quality control was difficult.

One of the reasons why scissors have to be hand-finished is that the scissors blade has a complex shape that is difficult to machine with normal machine tools. That is, as shown in FIG. 4, it is necessary to form concave surfaces to and 10' having an arcuate cross section on the opposing surfaces of the scissor blade 1.1'' using a grinder or the like.

This concave surface 10.10" forms a clearance angle α of the cutting edge, and when the pair of blades are rubbed together during use, this clearance angle α plays an important role in determining the sharpness of the scissors, but the clearance angle α The blade changes slightly depending on the radius of the grinder during manufacturing, the angle and direction of contact of the scissors with the grinder, etc., and it depends on the skill of the craftsman.Also, as shown in Figure 5, the change in the longitudinal direction of the blade The intersection angle β (the angle of curvature of the blade with respect to the line connecting the handle 1d and the intersection contact surface 1b) also plays an important role in the cutting of scissors, but the formation of this intersection angle β is also a long-standing goal of craftsmen. It was turning into an experience.

However, in recent years, precision casting, forging, press forming, NC
With the development of precision machining technologies such as electric discharge machining, laser machining, and micro welding, an environment has been created in which scissor blades with complex and delicate shapes such as those mentioned above can be machined automatically without manual work. Demand for mass production of high-quality scissors is increasing.

[Problem that the invention seeks to solve]

The present invention has been made from the above-mentioned viewpoint, and its purpose is to be able to mass-produce high-quality scissors with excellent sharpness by automatic processing instead of manual processing, and to also improve quality control at that time. An object of the present invention is to easily provide a new shape of scissors.

[Means for solving problems]

The above objective is achieved by forming a contact area centered on the shaft support hole at the intersection of a pair of blades of the scissors that are rotatably supported so as to cross each other into a perfect plane for both blades. It is possible.

[For production]

With the above configuration, when attaching the blade to the jig or chuck of an automatic processing machine, the completely flat part centered on the shaft support hole can be used as a reference surface, so the above-mentioned It is now possible to automatically process complex shapes such as
This also facilitates quality control. Therefore, according to the present invention, it is possible to provide sharp, high-quality scissors at a relatively low cost.

Furthermore, when the scissors are closed, due to the above-mentioned intersection angle β, the two blades contact each other only at two points, the pivot portion and the tip of the blade, but with normal scissors, the scissors are rotated at a 90° angle. If you open it too close, there will be some play in the pivot part. The smaller the amount of play, the higher the quality of the scissors as the contact pressure at the cutting part of both blades can be maintained constant, and the scissors can maintain good sharpness for a long time. Since the contact area centered on the support hole is formed into a completely flat surface, there is less play (more excellent cutting quality than before can be ensured).

The shape of the contact area is preferably a circle, a semicircle, or an ellipse centered on the shaft support, and the surface roughness thereof is as follows:
5-10μ to maintain good rubbing of both blades.
It is recommended that it be approximately m Rwax.

[Example] Hereinafter, the configuration of the present invention will be specifically explained with reference to the drawings.

Fig. 1 is a plan view showing the intersection of one embodiment of the scissors according to the present invention, Fig. 2 is a plan view showing one of the blades, and Fig. 3 is a side view of the scissors in a closed state. .

As shown in Figures 1 to 3, scissors A has a pair of blades 1
and 1° at the intersection of both shaft support holes 1a and 1a"
It is rotatably supported by a screw 2 inserted into the blade, and by opening and closing the handles 1d and ld'', the blade parts IC and IC' approach and separate from each other to cut the object. In this respect, there is no particular difference from regular scissors.

Thus, the scissors A according to the present invention has contact areas 1b and 1b° (shaded areas in the figure, however, the blades are The contact area 1b' of No. 19 is hidden behind the back side and cannot be seen in FIG.

The shape and surface roughness of the contact area tb (lb') affect the contact resistance and the opening/closing operation of the scissors, but the shape is preferably circular or semicircular with the pivot hole at the center. , an elliptical shape, or an arc shape depending on the case, and the surface roughness is recommended to be about 5 to 10 μmRmax as described above. Of course, these can be changed as appropriate depending on the use of the scissors.

In order to form the contact areas 1b and lb' completely flat, the material is cut within the machining range of the contact surface so that the sliding portion of the blade and this contact surface can be maintained in a parallel state. The contact surfaces facing each other are formed by mechanical or electrical processing means. Since the contact surfaces facing each other are in arbitrary surface contact, certain parts will not wear out, but if the effect becomes inferior after long-term use, it can be reprocessed if necessary. It is possible.

Therefore, when the blades 1 and 1" are automatically machined using an electrical discharge machining device, a laser processing device, or other various automatic machine tools, the contact areas 1b and tb" formed in a planar shape as described above are used. By attaching this to a jig or chuck of the machine tool and using this as a reference surface, the clearance angle α of the blade portions 1c and 1c1 and the crossing angle β of the blade can be automatically and accurately processed.

〔Effect of the invention〕

Since the present invention has a ridge-like structure, high-quality scissors that can be used for hairdressing and other professional purposes can be manufactured at a relatively low cost by automatic processing without manual work. , quality control becomes easier, and high-quality scissors can be stably supplied.

Note that the present invention is not limited to the embodiments on the ridges,
It is intended to encompass all modifications that can be readily deduced by those skilled in the art from the above description.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the intersection of one embodiment of the scissors according to the present invention, Fig. 2 is a plan view showing one of the blades, Fig. 3 is a side view of the scissors in a closed state, and Fig. 4 The figure is a cross-sectional view perpendicular to the axis of the blade of a general scissor, and FIG. 5 is a side view of one blade. 1.11・−・・・−・Blade

Claims (1)

[Claims] 1. A pair of scissors, characterized in that a contact area centered on a pivot hole at the intersection of a pair of blades that are rotatably supported so as to intersect with each other is formed into a perfect plane for both blades.