JPS5923824B2 - Oufukushikidenki Razorinosotoba - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an arrangement of hair introduction holes in an outer cutter in a reciprocating electric shaver.

When shaving is performed by applying a reciprocating electric razor to the skin, the inner blade B contacts the lower surface of the flexible outer blade A disposed in an arch shape and moves back and forth, as shown in Figure 2. As shown in the figure, the contact shape between the outer cutter A and the skin is approximately elliptical, and the contact pressure between the outer cutter A and the skin at that part is 3-3 on the X-X cross section and the Y-X cross section. It is known that the amount of protrusion of the skin from the outer cutter A is proportional to the contact pressure.

However, since the outer diameter of the hair introduction hole of the outer blade A of this type of conventional reciprocating electric shaver is the same across the entire outer blade A, when shaving by pressing the skin against the outer blade A, , the amount of protrusion of the skin from the outer blade A differs in some areas, which has the disadvantage of shaving unevenly in some areas and irritating the skin.

Therefore, an object of the present invention is to provide an outer blade for a reciprocating electric shaver that can make the amount of protrusion of the skin uniform.

As shown in FIG. 5, the outer cutter according to the present invention has whisker introduction holes a whose diameters gradually increase outward from the center of the outer cutter A so as to have a substantially elliptical shape.

The outer diameter of each crack introducing hole a is selected in accordance with the contact pressure distribution, since the contact shape and contact pressure distribution between the outer cutter A and the skin are known.

As mentioned above and shown in FIGS. 3 and 4, the contact pressure of the skin is strongest at the center of the approximately elliptical contact surface of the skin with the outer blade, and decreases as it moves away from the center, and The contact pressure is the same on any of the same nodal circles within the hole, and as shown in FIG. 6, the amount of skin protrusion is proportional to the contact pressure up to a certain size if the hole size is the same.

Therefore, the whisker introduction holes a arranged in an elliptical shape have the same size and the same contact pressure, so that the amount of protrusion of the skin is the same.

On the other hand, if the contact pressure is the same, the amount of skin protrusion increases as the whisker introduction holes become larger. Therefore, if the whisker introduction holes are gradually enlarged in a similar manner from the center side of the concentric ellipse to the outside, the contact pressure will gradually decrease. As a result, the amount of protrusion of the skin disappears even in the radial direction of the ellipse, and therefore the amount of protrusion of the skin becomes uniform as a whole.

As described above, in the outer cutter of the present invention, the whisker introduction holes are arranged in a substantially elliptical shape, and the whisker introduction holes are gradually sharpened in a similar manner from the center side to the outside. Keeping the amount of protrusion constant in all parts is a good idea, and has the effect of preventing uneven shaving and skin irritation.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view of a conventional reciprocating electric shaver, Fig. 2 is a plan view showing the shape of contact between the outer blade and the skin, and Fig. 3 is a cross-sectional view of the outer blade and the skin. Fig. 4 is a contact pressure distribution diagram between the outer blade and the skin along the Y-Y line in Fig. 2. Fig. 5 is a plan view showing an embodiment of the present invention. is a relationship diagram of the amount of protrusion of the skin with respect to the contact pressure. A...Outer blade, a...Hair introduction hole.

Claims (1)

[Scope of Claims] 1. The whisker introduction holes are arranged in a concentric elliptical shape, and the shapes and dimensions of the whisker introduction holes arranged in the ellipse are the same. An outer blade of a reciprocating electric razor in which the beard introduction holes are gradually sharpened in a similar manner from the center side of the concentric ellipse outward.