Rotary electric razor

Abstract

We provide a rotary electric razor with a design that allows for a smoother shave while also extending the lifespan of the outer blade. [Solution] The rotary electric razor 1 comprises a main body 2 having an electric motor 9 and a head 3 connected to the main body 2. The head 3 has a blade unit 4, and the blade unit 4 has an outer blade portion 5 and an inner blade portion 6. The outer blade portion 5 has an outer blade 5a with a plurality of holes 5c formed around a first axis P1. The inner blade portion 6 has a plurality of inner blades 6a and a base portion 6b on which the inner blades 6a are arranged around the first axis P1. The base portion 6b is driven by the electric motor 9, causing the inner blades 6a to slide against the sliding contact surface 5d of the outer blade 5a. The outer blade 5a has an outer area around which a first curved portion 7a following the top portion 5f is located, and an inner area around which a second curved portion 7b following the top portion 5f is located, and the first curved portion 7a is longer than the second curved portion 7b.

Description

Technical Field

[0001] The present invention relates to a rotary electric razor.

Background Art

[0002] Conventionally, a rotary electric razor having a donut-shaped outer blade and a plurality of inner blades that slidably contact the sliding surface of the outer blade has been proposed (Patent Document 1: Japanese Patent Laid-Open No. 8-196753, Patent Document 2: Japanese Patent Laid-Open No. 8-196754). Also conventionally, a rotary electric razor provided with a blade unit having an outer blade having an annular beard shaving surface on the outside and an inner blade that slidably contacts the sliding surface of the outer blade is known (Patent Document 3: Japanese Patent Laid-Open No. 2015-070927).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Rotary electric razors have advantages such as a smooth feel when shaving the beard by making the outer area of the outer blade into an arc shape. However, in the configurations described in Patent Document 1 and Patent Document 2, since the depression in the center of the outer blade is deep, the frictional resistance when the inner blade slidably contacts the outer blade increases, and the rotation of the inner blade becomes dull. Moreover, the increase in the frictional resistance between the outer blade and the inner blade causes a reduction in the life of the outer blade. In the configuration in which a plurality of the blade units described in Patent Document 3 are arranged, it becomes extremely difficult to increase the size of the outer blade compared to a configuration with one blade unit.

Means for Solving the Problems

[0005] This invention has been made in view of the above circumstances, and aims to provide a rotary electric razor with a configuration that allows for a smoother feel on the skin during shaving while also extending the lifespan of the outer blade.

[0006] As one embodiment, the above problem is solved by the solution disclosed below.

[0007] The rotary electric razor according to the present invention comprises a main body having an electric motor that drives a first shaft, and a head connected to the main body, the head having a blade unit, the blade unit having an outer blade portion and an inner blade portion, the outer blade portion having an outer blade with a plurality of holes formed around a first axis, the inner blade portion having a plurality of inner blades and a base portion on which the inner blades are arranged around the first axis, the first shaft is connected to the base portion, and the inner blades are in sliding contact with the sliding contact surface of the outer blade, the outer blade is characterized in that an outer area around which a first rounded portion following the top is encircled and an inner area around which a second rounded portion following the top is encircled are continuous, and the first rounded portion is longer than the second rounded portion.

[0008] With this configuration, the outer area of ​​the outer blade's contact surface, where the peripheral speed is faster than the inner area, is wider, allowing for a wider shave due to the centrifugal force applied to the inner blade as the base rotates. Furthermore, the inner area of ​​the outer blade's contact surface, where the peripheral speed is slower than the outer area, is narrower, reducing frictional resistance and allowing for smoother beard cutting. In addition, the reduced frictional resistance between the outer and inner blades extends the lifespan of the outer blade.

[0009] As an example, the outer blade is made of an electroformed body and has multiple holes formed therein that are sized to allow hair to enter. These holes are provided as a single type or a combination of multiple types, such as slit-shaped through-holes or circular or elliptical through-holes. The shape of the holes can be circular, rhombic, square, triangular, or other known geometric shapes. The type of hole can be one type or a combination of two or more types.

[0010] As an example, the thickness of the first rounded portion is greater than the thickness of the second rounded portion. With this configuration, by increasing the thickness of the outer area of ​​the outer blade's sliding contact surface, where the peripheral speed is faster than that of the inner area, it is easy to increase the strength of the outer area, which is more prone to wear than the inner area due to the influence of centrifugal force. Furthermore, by making the thickness of the inner area, which is less prone to wear than the outer area, thinner, it is easy to improve the ability to conform to the skin during shaving.

[0011] As an example, the inner blade is mounted at a position slightly outside the radius of the base relative to the first axis, and the cutting edge of the inner blade is shaped to match the first and second rounded sections. This configuration increases the peripheral speed of the inner blade, improving its ability to cut beards, and allows for smooth shaving by making the inner blade slide against a wide area. Furthermore, the frictional resistance between the outer blade and the inner blade is reduced, extending the life of the outer blade.

[0012] As an example, the inner blade has a support that supports the cutting edge, and the inner blade portion has a leaf spring that pushes the support toward the sliding surface. With this configuration, both a force that pushes the sliding surface due to the restoring force of the leaf spring and a force that pushes the inner blade toward the outer circumference of the outer blade due to the centrifugal force act on it, so that the inner blade can slide over a wide area and shave smoothly.

[0013] As an example, the main body has a gripping part, a blade holder, and a second shaft, the blade holder is tiltably connected to the gripping part via a connecting part, the head has a mounting part on which the blade units are arranged in multiple locations and a blade frame that holds the mounting part, the blade frame is connected to the blade holder, the outer blade part has a disc-shaped cover positioned in the center of the outer blade, a receiving part that supports the first shaft is formed inside the cover, the second shaft is connected to the first shaft and the electric motor is connected to the second shaft. With this configuration, even in a configuration with multiple blade units, each inner blade of each blade unit rotates stably, and excellent shaving performance is achieved even on areas with large undulations from the chin to the face.

[0014] For example, the first shaft may be the output shaft of the electric motor itself. In this case, the output shaft can be directly connected to the base, which significantly reduces the number of parts. Moreover, it can be made compact and simple. For example, the blade unit may be single, or it may be multiple.

[0015] The rotary electric razor according to the present invention comprises a main body having an electric motor that drives a first shaft, and a head connected to the main body, the head having a blade unit, the blade unit having an outer blade portion and an inner blade portion, the outer blade portion having an outer blade with a plurality of holes formed around a first axis, the inner blade portion having a plurality of inner blades and a base portion on which the inner blades are arranged around the first axis, the first shaft is connected to the base portion, and the inner blades are in sliding contact with the sliding contact surface of the outer blade, the cutting edge of the inner blade is shaped to match the radius shape of the outer area of ​​the outer blade, and the inner blade is mounted at a position further outward than half the radius of the base portion with respect to the first axis.

[0016] This configuration increases the peripheral speed of the inner blade, improving its beard-cutting ability, and allows for smooth shaving by ensuring the inner blade makes contact over a wide area. Furthermore, the area of ​​the outer blade's contact surface closest to the first axis does not come into contact with the inner blade, reducing frictional resistance and allowing for smoother beard cutting. In addition, the reduced frictional resistance between the outer and inner blades extends the lifespan of the outer blade. [Effects of the Invention]

[0017] According to the present invention, a rotary electric razor can be realized that provides a smoother feel on the skin during shaving while also extending the lifespan of the outer blade. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a schematic perspective view showing an example of a rotary electric razor according to the first embodiment of the present invention. [Figure 2]Figure 2 is a schematic front view of the rotary electric razor shown in Figure 1. [Figure 3] Figure 3 is a schematic longitudinal sectional view of the rotary electric razor shown in Figure 1 viewed from the side. [Figure 4] Figure 4 is an enlarged view of the portion surrounded by the broken line E in Figure 3. [Figure 5] Figure 5 is an enlarged view showing an enlarged outer blade portion in Figure 3. [Figure 6] Figure 12 is an enlarged view showing an enlarged inner blade portion in Figure 3. [Figure 7] Figure 7 is a schematic structural development view of the head related to the rotary electric razor shown in Figure 1. [Figure 8] Figure 8 is a schematic front view showing a first example of the rotary electric razor according to the second embodiment of the present invention. [Figure 9] Figure 9 is a schematic longitudinal sectional view of the rotary electric razor shown in Figure 8 viewed from the side. [Figure 10] Figure 10 is a schematic front view showing a second example of the rotary electric razor according to the second embodiment of the present invention. [Figure 11] Figure 11 is a schematic longitudinal sectional view of the rotary electric razor shown in Figure 10 viewed from the side. [Figure 12] Figure 12A is a schematic plan view of the donut-shaped outer blade portion according to the above-described embodiment. Figure 12B is a schematic front view of the donut-shaped outer blade portion according to the above-described embodiment. Figure 12C is a schematic bottom view of the donut-shaped outer blade portion according to the above-described embodiment. [Figure 13] Figure 13A is a schematic plan view of the dome-shaped outer blade portion according to the above-described embodiment. Figure 13B is a schematic front view of the dome-shaped outer blade portion according to the above-described embodiment. Figure 13C is a schematic bottom view of the dome-shaped outer blade portion according to the above-described embodiment.

Embodiments for Carrying Out the Invention

[0019] Embodiments of the present invention will be described in detail below with reference to the drawings. This embodiment is a handheld rotary electric shaver 1 having a head 3 on which one to three blade units 4 are arranged. Here, in order to make it easier to explain the positional relationships of the various parts of the rotary electric shaver 1, the directions are indicated by X, Y, and Z arrows in the figures. When actually using the rotary electric shaver 1, it is not limited to these directions and can be used in any direction without any problems. In addition, in all the figures used to explain the embodiment, the same reference numerals are used for members having the same function, and repeated explanations may be omitted.

[0020] [First Embodiment] As shown in Figures 1 and 2, the rotary electric shaver 1A of the first embodiment has a head 3 on which three blade units 4 are arranged. In this embodiment, the rotational force of the electric motor 9 rotates the second shaft 8b and the first shaft 8a, and the rotational force is transmitted to the base 6b on which the inner blade 6a is arranged, thereby rotating the base 6b. Note that there may be two blade units 4 or four or more.

[0021] In the examples shown in Figures 1 and 2, the front of the main body 2 is an operation panel, and a push-button type power switch 17 is located there. For example, the blade holder 12 is connected to the gripping part 15 via a connecting part 14, and the head 3 is configured to be tiltable relative to the main body 2.

[0022] As shown in Figures 1 to 3, the main body 2 comprises a gripping part 15 for the user to hold and a head 3 that is detachably connected to a connecting part 14 provided on the gripping part 15. A trimming blade 18 is located on the back side of the main body 2. The main body 2 incorporates an electric motor 9, a battery 16 capable of supplying DC power to the electric motor 9, and a control unit 19 that is activated by a power switch 17 and controls the operation of the electric motor 9. For example, a power supply terminal 21 is located at the bottom of the back side of the main body 2, and power can be supplied to the battery 16 from an external power source via the power supply terminal 21. For example, the output shaft 8c of the electric motor 9 is connected to a second shaft 8b in a second drive unit having multiple gears. The second shaft 8b is a second driven shaft. Conventional technology can be applied to the second drive unit.

[0023] The blade holder 12 has multiple first shafts 8a arranged on it; for example, three first shafts 8a are arranged at predetermined intervals. For example, a second shaft 8b is connected to a first shaft 8a in a first drive unit having multiple gears. Therefore, the second shaft 8b is connected to the first shaft 8a, and the electric motor 9 is connected to the second shaft 8b. The first drive unit can utilize prior art.

[0024] The head 3 has a mounting section 13 on which three blade units 4 are arranged at predetermined intervals, and a blade frame 11 that holds the mounting section 13. For example, the mounting section 13 has a groove shape at the intermediate position between the blade units 4, and the blade units 4 are configured to swing due to the groove shape. In addition, the mounting section 13 is biased and pushed up by the restoring force of a plate-shaped spring 41 arranged on the blade frame 11.

[0025] Figure 4 is an enlarged view of the portion enclosed by the dashed line E in the head 3 according to this embodiment. Figure 5 is an enlarged view showing the outer blade portion 5 of the head 3. Figure 6 is an enlarged view showing the inner blade portion 6 of the head 3. Figure 7 is a schematic structural unfolded view of the head 3. Each blade unit 4 has an outer blade portion 5 and an inner blade portion 6. As an example, the outer blade portion 5 has a donut-shaped or annular outer blade 5a and a disc-shaped cover 5b. The outer blade 5a has an outer surface and an inner sliding contact surface 5d into which the cutting edge 6c of the inner blade 6a slides, and has multiple slit-shaped holes 5c or round holes 5c of a size that allows hairs to enter. The outer blade 5a is a metal part with multiple holes 5c formed in the circumferential direction.

[0026] The outer blade section 5 has a resin or metal cover 5b attached to a first axis P1 that passes through the center of the outer blade 5a. The lower part of the cover 5b has a protrusion on the first axis P1, and the upper part of the base 6b has a recess on the first axis P1. The protrusion and recess combine to allow for more precise positioning of the outer blade 5a and inner blade 6a relative to the first axis P1. In some cases, the outer blade section 5 may have no cover 5b, and the center of the outer blade 5a may be closed.

[0027] The outer blade 5a is made of an electroformed body. The outer blade 5a is manufactured by electroforming, which involves applying a thick plating, such as nickel plating, to the surface of the master mold, and then peeling off this thick plating from the master mold and shaping it. Electroforming allows for the formation of a strong, thin, and highly accurate outer blade 5a. As an example, the electroformed body is formed from two or more layers.

[0028] The inner blade section 6 has a plurality of inner blades 6a and a resin base 6b on which these metal inner blades 6a are arranged at predetermined intervals around a first axis P1. As an example, 3 to 8 inner blades 6a are attached to the base 6b. As an example, 6 inner blades 6a are attached to the base 6b. Each inner blade 6a has a window portion fitted into a protrusion on the base 6b so that it can maintain an upright position. The inner blades 6a are movable in the left and right and front and back directions by more than 0 and within 0.25 mm, and are configured to self-align as the cutting edge 6c slides against the sliding contact surface 5d in conjunction with the rotational movement of the base 6b. In other words, the inner blades 6a are configured to move in a direction that suppresses the frictional force between the cutting edge 6c and the sliding contact surface 5d. As an example, the inner blades 6a are made of stainless steel, nickel alloy, or other known metals or alloys.

[0029] As shown in Figure 7, the inner blade 6a has a support 6a1 that supports the cutting edge 6c, and the cutting edge 6c is bent relative to the support 6a1. The inner blade portion 6 has a leaf spring 6e that pushes the support 6a1 toward the sliding surface 5d. The leaf spring 6e is annular and in contact with the lower surface of the support 6a1. The leaf spring 6e simultaneously pushes each inner blade 6a at each base portion 6b toward the sliding surface 5d. As a result, the restoring force of the leaf spring 6e pushes the sliding surface 5d, and the centrifugal force pushes the inner blade 6a toward the outer circumference of the outer blade 5a, allowing the inner blade 6a to slide over a wide area and shave smoothly. Furthermore, when trimming beards in uneven areas such as under the chin with the outer blade 5a in close contact with the skin, the outer blade 5a and the cutting edge 6c elastically deform and come into close contact with the uneven area, trimming the beard smoothly. As an example, the inner blade 6a has its cutting edge 6c bent in the direction of travel relative to the support 6a1.

[0030] The base portion 6b has radially arranged grooves 6d that slope downward in the radial direction. The hair clippings cut by the sliding contact between the outer blade 5a and the inner blade 6a are efficiently discharged outside the base portion 6b through the downward-sloping grooves 6d due to the action of the hair clippings' own weight and the centrifugal force acting on them. Therefore, the accumulation of hair clippings that would hinder the rotational movement of the base portion 6b can be prevented.

[0031] The base 6b has a recess formed in the lower center, and the tip of the first shaft 8a fits into and connects to the recess. The second shaft 8b is connected to the first shaft 8a, and the electric motor 9 is connected to the second shaft 8b. Therefore, when the power switch 17 is pressed, the control unit 19 is activated, and the electric motor 9 is operated under the control of the control unit 19. The drive shaft of the electric motor 9, the second shaft 8b, the first shaft 8a, and the base 6b move in conjunction, causing the base 6b to rotate around the first axis P1 passing through the first shaft 8a.

[0032] In the examples shown in Figures 4 and 5, the outer blade 5a has a continuous outer area around the first curved section 7a that follows the top 5f and an inner area around the second curved section 7b that follows the top 5f. In this embodiment, the first curved section 7a is longer than the second curved section 7b. As a result, the outer area of ​​the sliding contact surface 5d of the outer blade 5a, where the peripheral speed is faster than the inner area, is wider, allowing for shaving over a wider area due to the centrifugal force applied to the inner blade 6a as the base 6b rotates. Furthermore, the inner area of ​​the sliding contact surface 5d of the outer blade 5a, where the peripheral speed is slower than the outer area, is narrower, reducing frictional resistance and allowing for smoother cutting of the beard.

[0033] In this specification, the outer area refers to the area outside the top 5f, which is further from the first axis P1 than the inner area, and in which multiple holes 5c for introducing whiskers are formed, and in which the inner blade 6a slides against. In this specification, the inner area refers to the area inside the top 5f, which is closer to the first axis P1 than the outer area, which is also formed with multiple holes 5c for introducing whiskers, and in which the inner blade 6a slides against.

[0034] As an example, the total size of all holes 5c in the outer area following the top 5f is greater than the total size of all holes 5c in the inner area following the top 5f. In other words, the opening area of ​​the outer periphery is greater than the opening area of ​​the inner periphery. With this configuration, even if many hairs enter the holes 5c in the outer area and the cutting resistance increases, it is easy to ensure good shear force through the centrifugal force described above. The factors that affect the opening area are the size of each hole 5c, the rib width, and the number of holes 5c.

[0035] As an example, in the outer blade 5a, the opening area of ​​each hole 5c in the outer area following the top 5f is larger than that of the inner area following the top 5f. In other words, the opening area of ​​each hole 5c in the outer peripheral area is larger than that of each hole 5c in the inner peripheral area. With this configuration, even if many hairs enter the openings in the outer area and the cutting resistance increases, it is easy to ensure good shear force through the centrifugal force described above. The factors that affect the opening area are the size of each hole 5c, the rib width, and the number of holes 5c.

[0036] The outer blade 5a is made of an electroformed body. As shown in Figure 5, the first thickness T1 of the first curved portion 7a is thicker than the second thickness T2 of the second curved portion 7b. With this configuration, by increasing the thickness of the outer area of ​​the sliding contact surface 5d of the outer blade 5a, where the peripheral speed is faster than that of the inner area, it is easy to increase the strength of the outer area, which is more susceptible to wear than the inner area due to the centrifugal force applied to the inner blade 6a. Furthermore, by making the thickness of the inner area, which is less susceptible to wear than the outer area, thinner, it is easy to improve the ability to follow the skin during shaving.

[0037] The holes 5c are provided as single or multiple types of slit-shaped through-holes or circular or elliptical through-holes. The shape of the holes 5c can be circular, rhombic, square, triangular, or other known geometric shapes. The types of holes 5c can be one or a combination of two or more types.

[0038] As shown in Figures 5 and 6, the inner blade 6a is mounted at a position slightly outside the first radius R1, which is the radius of the base 6b, relative to the first axis P1. In other words, the second radius R2, which extends from the first axis P1 to the inner end 6g of the inner blade 6a, is greater than half the first radius R1. Furthermore, the cutting edge 6c of the inner blade 6a has a curved shape that matches the first and second curved sections 7a and 7b. In addition, the outer end 6h of the inner blade 6a is mounted at a position further outside the first radius R1. This configuration increases the peripheral speed of the inner blade 6a, improving its beard cutting ability, and allows for smooth shaving by enabling the inner blade 6a to slide over a wide area.

[0039] Next, a first example of the second embodiment will be described below. Here, components having the same function as those in the first embodiment are denoted by the same reference numerals.

[0040] [Example of the second embodiment] As shown in Figures 8 and 9, the rotary electric razor 1B of the first example of the second embodiment has a head 3 on which one blade unit 4 is arranged. In this embodiment, the output shaft 8c of the electric motor 9 is directly connected to the base 6b, and the base 6b is rotated by directly transmitting the rotational force of the electric motor 9. In other words, the second embodiment is a configuration in which the first shaft 8a and the second shaft 8b of the first embodiment are eliminated, and the output shaft 8c takes on the function of the first shaft 8a.

[0041] The main body 2 has a cylindrical or straight shape that is easy for the user to grip. For example, the main body 2 has a removable lid at the bottom. The user removes the lid, inserts the dry cell battery 26, reattaches the lid, and turns on the power switch located on the side of the main body 2 to use it. This configuration makes it easy to create a shape that is easy to grasp with the fingers.

[0042] In the first example, the outer blade portion 5 has a donut-shaped or annular outer blade 5a. The outer blade 5a is made of an electroformed body and has multiple holes of a size that allows hair to enter. The inner blade portion 6 has a plurality of inner blades 6a and a base portion 6b on which these inner blades 6a are arranged at predetermined intervals around a first axis P1. The techniques of the first embodiment described above can be applied to the outer blade portion 5 and the inner blade portion 6.

[0043] Next, a second example of the second embodiment will be described below. Here, components having the same function as those in the first embodiment are denoted by the same reference numerals.

[0044] [Second example of the second embodiment] As shown in Figures 10 and 11, the second example of the rotary electric razor 1C of the second embodiment has a head 3 on which one blade unit 4 is arranged. In this embodiment, the output shaft 8c of the electric motor 9 is directly connected to the base 6b, and the base 6b is rotated by directly transmitting the rotational force of the electric motor 9. The structure of the main body 2 in the second example is the same as in the first example.

[0045] In the second example, the outer blade portion 5 has a dome-shaped or hemispherical outer blade 25a. The outer blade 25a is made of an electroformed body and has multiple holes of a size that allows hair to enter. The inner blade portion 6 has a plurality of inner blades 6a and a base portion 6b on which these inner blades 6a are arranged at predetermined intervals around a first axis P1. The techniques of the first embodiment described above can be applied to the outer blade portion 5 and the inner blade portion 6.

[0046] Next, the donut-shaped outer blade portion 5 in the embodiment of the present invention will be described below.

[0047] [Example 1] As shown in Figures 12A to 12C, the outer blade portion 5 has a donut-shaped or annular outer blade 5a and a disc-shaped cover 5b. The outer blade 5a is made of an electroformed body with a two-layer or multi-layer structure. The main material of the outer blade 5a is nickel or a nickel alloy, and an outer layer made of palladium or a palladium alloy is formed on the outside of the main material layer. The outside of the palladium layer is treated with chromic acid. The palladium layer reduces surface roughness and improves the feel. The chromic acid treatment prevents surface oxidation and extends the lifespan.

[0048] The first thickness T1 of the first rounded portion 7a of the outer blade 5a is, for example, 50 to 150 μm. For example, the first thickness T1 is 75 to 125 μm. For example, the first thickness T1 is 90 to 110 μm.

[0049] The first thickness T1 is thicker than the second thickness T2 of the second rounded portion 7b. For example, the first thickness T1 is 10 to 25 μm thicker than the second thickness T2. For example, the first thickness T1 is 5 to 20 μm thicker than the second thickness T2.

[0050] Next, the dome-shaped outer blade portion 5 in the embodiment of the present invention will be described below.

[0051] [Example 2] As shown in Figures 13A to 13C, the outer blade portion 5 has a dome-shaped or hemispherical outer blade 25a. The outer blade 5a is made of an electroformed body with a two-layer or multi-layer structure. As described above, the peripheral speed of the inner blade 6a is increased to improve the beard cutting ability, and the inner blade 6a is made to slide over a wide area to allow for a smooth shave.

[0052] According to the above-described configurations, a rotary electric razor 1 can be obtained that provides a smooth feel on the skin during shaving while extending the lifespan of the outer blade. It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the scope of the present invention. [Explanation of Symbols]

[0053] 1, 1A, 1B, 1C Rotary electric razor 2 Main unit 3 heads 4-blade unit 5 Outer blade section, 5a Outer blade, 5b Cover, 5c Hole, 5d Sliding contact surface, 5e Mounting section 5f top, 5g inner edge, 5h outer edge 6 inner blade portion, 6a inner blade, 6a1 support, 6b base, 6c cutting edge, 6d groove portion 6e leaf spring, 6f fixed part, 6g inner end, 6h outer end 7a First rounded section, 7b Second rounded section 8a First shaft, 8b Second shaft, 8c Output shaft 9 Electric motor 11 Blade frame 12 Blade holder 13 Mounting part 14 Connecting part 15 Gripping part 16 batteries 17 Power switch 18. Edge trimming blade 19 Control Unit 21 Power supply terminal P1 1st axis P2 2nd axis R1 First Radius R2 2nd radius T1 First thickness T2 Second thickness

Claims

1. The device comprises a main body having an electric motor that drives a first shaft, and a head connected to the main body, the head having a blade unit, the blade unit having an outer blade portion and an inner blade portion, the outer blade portion having an outer blade with a plurality of holes formed around a first axis, the inner blade portion having a plurality of inner blades and a base portion on which the inner blades are arranged around the first axis, the first shaft being connected to the base portion, and the inner blades slidingly contacting the sliding contact surface of the outer blade, the outer blade having an outer area around which a first rounded portion following the top is encircled and an inner area around which a second rounded portion following the top is encircled, and the first rounded portion being longer than the second rounded portion. A rotary electric razor characterized by [feature].

2. The inner blade is mounted at a position further outward than half the radius of the base relative to the first axis, and the cutting edge of the inner blade is shaped to match the first and second rounded portions. A rotary electric razor according to claim 1, characterized by the following:

3. The inner blade has a support that supports the cutting edge, and the inner blade portion has a leaf spring that pushes the support toward the sliding surface. A rotary electric razor according to claim 2, characterized by the following:

4. The outer blade is made of an electroformed body, and the thickness of the first rounded portion is greater than the thickness of the second rounded portion. A rotary electric razor according to any one of claims 1 to 3, characterized by the above.

5. The main body has a gripping portion, a blade support base, and a second shaft, the blade support base is tiltably connected to the gripping portion via a connecting portion, the head has a mounting portion on which the blade units are arranged at multiple locations, and a blade frame that holds the mounting portion, the blade frame is connected to the blade support base, the outer blade portion has a disc-shaped cover positioned in the center of the outer blade, a support portion for the first shaft is formed inside the cover, the second shaft is connected to the first shaft, and the electric motor is connected to the second shaft. A rotary electric razor according to any one of claims 1 to 3, characterized by the above.

6. The device comprises a main body having an electric motor that drives a first shaft, and a head connected to the main body, the head having a blade unit, the blade unit having an outer blade portion and an inner blade portion, the outer blade portion having an outer blade with a plurality of holes formed around a first axis, the inner blade portion having a plurality of inner blades and a base portion on which the inner blades are arranged around the first axis, the first shaft is connected to the base portion, the inner blades are in sliding contact with the sliding contact surface of the outer blade, the cutting edge of the inner blade is shaped to match the radius shape of the outer area of ​​the outer blade, and the inner blade is mounted at a position further outward than half the radius of the base portion with respect to the first axis. A rotary electric razor characterized by [feature].

7. The inner blade has a support that supports the cutting edge, and the inner blade portion has a leaf spring that pushes the support toward the sliding surface. A rotary electric razor according to claim 6, characterized by the following:

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