JPS6250153B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an outer cutter for a rotary electric shaver having a convex curved surface such as a so-called dome-shaped outer cutter with an arch-shaped cross section, a donut-shaped cutter having a concave portion in the center, etc. It is an object of the present invention to provide a structure of an outer cutter that can strengthen the mechanical strength of the hem portion of the peripheral edge of the convex curved portion, particularly the flange portion.

The outer blade of this type of electric shaver is generally made by electrodeposition, and in this case, the peripheral hem part, especially the flange part, on the holder side is thinner than the convex curved part with scattered hair introduction holes. In other words, during electrodeposition, the current from the anode plate is concentrated on the convex curved part of the master on which the electrically insulating thin film corresponding to the hair introduction hole is formed, so that the electrodeposited layer per unit area is The thickness inevitably becomes thinner. Therefore, the mechanical strength of this hem is significantly weaker than that of other parts, and there is a risk that it will easily crack or break due to pressing force during use.

Furthermore, due to the thin wall described above, the blade retaining ring may not be able to secure it completely, resulting in poor press-fitting, which may cause the outer cutter to be misaligned with the outer cutter holder or come off from the outer cutter holder. Ta.

This invention eliminates the above-mentioned drawbacks and will be explained below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an outer cutter holder screwed into a case body (not shown), and the outer cutter 2 of the present invention is applied to an electric shaver with rotating inner cutters, and is fitted into the holder 1.

This outer cutter 2 is made of a thin metal plate and is formed in a so-called dome shape, and a convex curved portion 3 thereof is provided with a large number of hair introduction holes 4 in a desired pattern. A hole or a narrow slit 8 in the shape of a short shelf is formed around the hem 5 of the outer cutter 2, for example, a falling part 6 following the periphery of the convex curved part 3 and a flange part 7 fitted to the holder 1. It is formed around the convex curved part 3, and the wall thickness t5 of that part is as shown in FIG.
The wall thickness is approximately equal to the wall thickness t3 of the portion .

This is because a protrusion 16 for a countersink is formed on the periphery of the back surface of the hair introduction hole 4 where the inner blade slides, and also in the hole or slit 8 of the flange portion 7 of the hem 5. By forming the protrusion 17 for the counter sink, the same thickness can be achieved. The reason why this hem portion 5 is made to have the same thickness as other parts is to prevent local deformation in this hem portion 5. Furthermore, as shown in an enlarged view in FIG. 2, the slit 8 is shaped like a groove so that the inner walls 8a and 8b on the bottom side are in contact with each other. This is to effectively prevent the deformation of No. 5.

Next, one example of the method for manufacturing the outer cutter 2 will be explained with reference to FIGS. 3A and 3B.

The outer cutter 2 of the present invention is produced using a commonly used electrodeposition method. First, as shown in FIG. 3A, a master 1 whose one side has a similar external shape to the outer cutter 2
Prepare 1. In other words, the master 11 has a convex curved portion 11a.
It has a shape with a hem portion 11b on the outer peripheral edge following this, and at the same time as forming the electrically insulating thin film 12 in a desired pattern on the convex curved portion 11a, the hem portion 1 is formed.
A short shelf-shaped electrically insulating thin film 13 is also formed on 1b. Thereafter, the master 11 connected to the cathode (not shown) and the anode plate (not shown) made of a metal capable of electrodeposition, such as copper, nickel, or nickel alloy, facing the master 11 are transferred to an electrodeposition bath. When primary electrodeposition for countersinking is carried out, primary electrodeposition layers 14 and 15 are formed on each portion where the electrically insulating thin films 12 and 13 are not applied, respectively, as shown in FIG.

Next, after the first electrodeposited layers 14 and 15 are subjected to a normal peeling treatment, the second electrodeposited layers 14' and 15 are further applied.
5' is formed, and after this electrodeposition is completed, the electrodeposited layers 14 and 15 are separated from the master 11, and the corresponding position of the electrically insulating thin film 12 becomes the hair introduction hole 4, and the corresponding position of the electrically insulating thin film 13 is formed. The position is obtained as slit 8.

In this case, since the first and second electrodeposition processing methods are performed so that the countersink protrusion 16 is formed on the periphery of the back surface of the hair introduction hole 4, the hole or slit 8 of the flange portion 7 is However, a protruding portion 17 is formed on the periphery of the back surface of the flange portion 7. As a result, the thickness t5 of the flange portion 7 becomes approximately the same as the thickness t3 of the convex curved portion 3, and mechanically Strength increases.

In order to bring the inner walls of the bottom side of the slit 8 into contact with each other, the electrically insulating thin film 13 may be set to be as fine as possible. The arrangement of the slits 8 can be appropriately selected such as arranging them in multiple rows as shown in FIG. The area ratio of the layer 15 is preferably selected within the range of 1:2 to 1:8.

As described above, in the outer cutter in which the countersink protrusion 16 is formed on the periphery of the back surface where the inner cutter of the hair introduction hole 4 slides, the flange portion 7 for fixing the outer cutter of the outer cutter 2 is also formed. By forming the protruding part 17 for the counter sink on the periphery of the back surface, the thickness of the flange part 16 is increased, and the protruding part 16 for the counter sink acts as a reinforcing rib, improving the strength. This prevents the outer cutter 2 from slipping or coming off when it is fixed to the outer cutter holder 1, and a reliable fixing force of the outer cutter 2 is obtained. Since it can be obtained at the same time as forming, it is easy to manufacture and suitable for mass production.

Note that even when the outer cutter 2 is formed into a donut shape by electrodeposition, the same method can be used.

[Brief explanation of the drawing]

FIGS. 1A and 1B are plan views showing an example of an electric shaver equipped with an outer cutter according to the present invention, and FIGS.
2 is an enlarged view of the portion A in FIG. 1, FIGS. 3 A and B are explanations showing an example of the method for manufacturing the outer cutter in FIG. 1A, and FIG. It is an explanatory view of a deformed structure of. 2... Outer blade, 4... Hair introduction hole, 7... Flange part, 16... Projection part, 17... Projection part.

Claims (1)

[Claims] 1. In an outer cutter in which a protruding portion 16 for a counter sink is formed on the periphery of the back surface where the inner cutter of the hair introduction hole 4 slides, the flange portion 7 for fixing the outer cutter of the outer cutter 2 also has a flange portion 7 on the periphery of the back surface. Projection part 1 for counter sink
The outer blade of a rotary electric shaver is formed by forming a 7.