JPH088949B2 - Electric razor outer blade - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an outer blade of an electric shaver manufactured by an electroforming method.

[Conventional technology]

The outer blade of the electric razor is manufactured by the following electroforming method. That is, after depositing a resist layer on the upper surface of the metal substrate, this layer is exposed in a predetermined pattern.
Next, the surface of the metal substrate in the exposed portion is etched, and then the resist layer is removed.
Then, the metal substrate is subjected to primary plating to form a primary plating layer portion A to be deposited below the surface of the metal substrate at a position corresponding to the exposed portion of the metal substrate, and to the non-exposed portion. At a corresponding position, the primary plating layer portion B deposited on the upper side of the surface of the metal substrate is formed. Finally, a release agent is applied to the entire surface of the primary plating layer, and then secondary plating is performed thereon. By this plating treatment, a secondary plating layer (that is, an outer blade) attached to the primary plating layer portion B is formed. The portion facing the primary plating layer portion A of the secondary plating layer is a hole through which whiskers pass, and
The hole edge becomes a cutting edge portion corresponding to the height of the primary plating layer portion B. The secondary plating layer as an outer blade formed in this way is separated from the metal substrate and provided as an outer blade.

Then, the conventional outer blade obtained by such a manufacturing method is provided with a central portion provided with innumerable holes of a size through which a whisker passes and a peripheral portion thereof as illustrated in Japanese Patent Publication No. 53-47745. A blind plate-shaped portion to be mounted, a plurality of fixing holes for mounting the mounting plate provided on the edge side of the blind plate-shaped portion, and if necessary, to form a boundary between the central portion and the blind plate-shaped portion And a transition part that is formed. In the transition part, for example, there are innumerable holes smaller than the hole in the central part and through which whiskers pass, but since this part does not contact the inner blade, shaving is not performed, and such transition part By doing so, the strength of the edge of the outer blade is increased.

Such an outer blade for a reciprocating electric shaver is attached to the outer cutter base by engaging both ends of a mounting plate attached to its edge with an engaging groove provided on the inner surface of the outer cutter base. On the other hand, it is attached in a state of being bent into a semi-cylindrical shape. The inner blade is slidably contacted with the inner surface of the central portion of the outer blade, and the whiskers passing through the hole in the central portion are cut by the inner blade and the cutting edge portion of the hole. , The central portion forms a whisker cutting area. And in such a conventional outer cutter, the aperture ratio per unit area in each part of the whisker cutting area was the same.

[Problems to be Solved by the Invention]

By the way, when the secondary plating is deposited by the electroforming method, the thickness of the plating layer is greatly influenced by the plating time and the current density. Then, according to the outer blade of the conventional configuration, the current density is not uniform in the central portion having the innumerable holes and the peripheral blind plate portion, and the current density of the blind plate portion is drastically reduced. Become. Therefore, the blind plate-shaped portion is thin and the central portion is thick, and there is a tendency that the central portion is thicker on the side of the apex where it is difficult to be influenced by the blind plate-shaped portion.

In the conventional outer blade having the above thickness tendency,
When shaving, the thickness of the outer cutter, which is most often used, is larger on the top side of the outer cutter, which makes it difficult to deepen the shave. It should be noted that in order to enable deep shaving, it is conceivable to increase the number of holes through which the beard passes, thus increasing the aperture ratio of the beard cutting region. In practice, this is not preferable because the portion is pushed through the hole and the skin is likely to be damaged by the inner blade. Further, as described above, the thickness of the top portion of the outer blade is large, so that it is difficult to bend. Therefore, there is a problem that it is not familiar with the inner blade and the sharpness is not good.

An object of the present invention is to provide an outer blade of an electric razor capable of deepening without damaging the skin and improving sharpness.

[Means for Solving the Problems] In order to achieve the above object, in the outer blade of the electric shaver of the present invention, the aperture ratio per unit area of the central portion on the top side of the whisker cutting region in which the inner blade is in sliding contact. Is smaller than the aperture ratio per unit area of the skirt portion located outside the central portion of the whisker cutting region.

[Action]

The outer blade of the above-mentioned configuration is made by electroforming, but due to the difference in the aperture ratio between the top center portion and the skirt portion in the whisker cutting area, during secondary plating in the production, a unit area of the whisker cutting area Since the current density in the central portion on the top side with a small aperture ratio per hit is small, the central portion on the top side can be formed thin. Since the central portion on the top side is thin in this way, the beard can be deeply shaved.
Along with this, the thin central portion on the top side as described above bends very easily and fits well with the inner blade, so that sharpness can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 3, 1 is a body case of a reciprocating electric razor,
It is projected from the top surface and is in the left-right direction (the third
An inner blade 3 is attached to an inner blade support shaft 2 that reciprocates in the front and back directions in the drawing). The inner blade 3 is biased upward by a coil spring 4 provided by winding the shaft 2. Further, an outer blade body 5 is detachably attached to the upper part of the main body case 1 so as to cover the inner blade 3. The outer blade body 5 is composed of an outer blade base 6 made of resin or light metal, and an outer blade 7 which is bent into a substantially semi-cylindrical shape and is attached so as to close the opening 6a of the outer blade base 6. Mounting plates 8 made of resin are attached to both side edges of the outer blade 7 by means such as heat staking, and both ends of these mounting plates 8 are provided on inner surfaces of both ends of the outer blade base 6, respectively, which are not shown in the drawings. The outer cutter 7 is attached to the outer cutter base 5 by being detachably engaged with the groove.
The inner blade 3 is in sliding contact with the inner surface of the outer blade 7 while being pressed by the coil spring 4.

The outer blade 7 is made by an electroforming method. The outer blade 7 is formed by forming innumerable holes of a size through which whiskers pass through on the entire inner surface surrounded by a peripheral edge 9 forming the outer shape thereof. In addition, in the present embodiment, the innumerable holes through which the whiskers pass have the same shape, but the present invention is not limited to this, and a plurality of kinds of holes having different shapes may be combined. The peripheral edge 9 is edging, whereby the outer blade 7
It is designed to prevent tearing inside.

In such an outer blade 7, a range surrounded by a two-dot chain line in FIG. 1 shows a whisker cutting region A in which the inner blade 3 is in sliding contact with the inner surface, and this region A is a top side central portion B, It is formed from the skirt portion C located outside thereof. In FIG. 1, the alternate long and short dash line indicates the central portion B on the top side and the skirt portion C.
In FIG. 3, θ1 indicates the angular range occupied by the central portion B on the top side, and θ2 indicates the angular range occupied by the whisker cutting area A in FIG. The central portion B on the top side is formed so that the aperture ratio per unit area thereof is smaller than the aperture ratio per unit area of the skirt portion C. Therefore, the width of the bridge between the adjacent hole edges in the innumerable holes in the top-side central portion B is larger than the width of the bridge between the adjacent hole edges in the innumerable holes in the skirt portion C.

Further, in the case of the present embodiment, the aperture ratio of the peripheral edge portion D of the outer blade 7 is also formed to be smaller than the aperture ratio per unit area of the skirt portion C. The boundary of the peripheral portion D is shown by the dotted line in FIG.
A plurality of fixing holes 10 are provided at both edges of the outer blade 7 along the length direction. These fixing holes 10 are much larger than the holes through which the whiskers pass, and the holes 10 are shaped by the hole edges 10a. Then, the hole edge 10a prevents tearing into the outer cutter 7.
A protrusion (not shown) for heat crimping the mounting plate 8 is inserted through these fixing holes 10. It should be noted that the use of the peripheral portion D of such a porous structure is advantageous in reducing abrupt thickness change between the peripheral portion D and the portion E adjacent thereto, and bending and stress at the boundary portion indicated by the dotted line above. However, in the present invention, the peripheral portion D and the portion E may be formed in a blind plate shape.

According to the outer blade 7 having such a configuration, the aperture ratio per unit area of the central portion B on the top side of the beard cutting area A with which the inner blade 3 is in sliding contact can be calculated as follows. Since the aperture ratio is smaller than the unit area, this outer blade 7
At the time of the secondary plating in the manufacturing of, the current density of the central portion B on the top side having a small aperture ratio per unit area becomes smaller than the current density of the skirt portion C. Therefore, the central portion B on the top side is formed thin, and the thickness thereof can be made equal to or less than the thickness of the skirt portion C. For example, the thickness of the outer cutter 7 is roughly as shown in FIG.

Thus, in the beard cutting area A, the central portion B on the top side
The thinness allows you to shave deeply. At the same time, as described above, since the thin central portion B on the top side can be bent very easily, the inner surface thereof fits very closely to the vicinity of the top of the inner blade 3 to improve the sharpness.

Further, the present invention is not limited to being applied only to the outer blade for the reciprocating electric shaver, but can be applied to the outer blade for the rotary electric shaver.

〔The invention's effect〕

According to the present invention configured as described above, the central portion on the top side in the whisker cutting region can be formed thin,
The beard can be deeply shaved in this thin top central portion, and there is no need to increase the size of the hole through which the beard passes for deepening so that the skin is not damaged and the deflection of the top central portion is extremely high. Because it will be easier
Improves the familiarity with the inner blade and improves sharpness.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a plan view of a reciprocating electric shaver outer blade, and Fig. 2 is a schematic view showing a change in thickness of the outer blade along line II-II in Fig. 1. 3 is a sectional view showing a part of the upper part of the reciprocating electric shaver. 7 ... Outer blade, A ... beard cutting area, B ... top center portion, C ... skirt portion.

Claims (1)

[Claims] 1. A whisker cutting area which is made by electrocasting and in which whisker cutting areas with which inner blades are in sliding contact are provided with innumerable holes, the whisker cutting area having a central portion on the top side of the whisker cutting area. An outer blade of an electric shaver, wherein an opening ratio per unit area is smaller than an opening ratio per unit area of a skirt portion located outside the central portion of the whisker cutting region.