WO2020054481A1

WO2020054481A1 - Rotary shaver

Info

Publication number: WO2020054481A1
Application number: PCT/JP2019/034446
Authority: WO
Inventors: 政秀 ▲徳▼田
Original assignee: 株式会社Ｔｏｋｕｄａ－Ａｒｄ
Priority date: 2018-09-11
Filing date: 2019-09-02
Publication date: 2020-03-19
Also published as: JP6525298B1; JP2020039651A

Abstract

[Problem] To provide a rotary shaver with which it is possible to cut beard suitably. [Solution] The present invention provides a rotary shaver 1 in which an outer blade 10 has a blade tip at the lower end of an inner wall of each of a plurality of slits 11, and an inner blade 20 includes a disc-shaped base 21 and a plurality of small blades 22 protruding from the base 21 toward the outer blade 10. A blade tip 23 of each of the plurality of small blades 22 has a shape which is curved inwardly of an upper surface 22a of each small blade 22. Each of the plurality of slits 11, when viewed in a rotating direction of the inner blade 20 with respect to the outer blade 10, has a shape which is inclined with an outer end positioned forwardly of an inner end, and which is curved so as to bulge backward in the rotating direction with a radius of curvature greater than that of the blade tip of each of the plurality of small blades 22. Each of the plurality of small blades 22 has a shape obtained by forming a groove in the base 21 and then bending the root of a resultant projection in a direction opposite to the rotating direction.

Description

Rotary shaver

The present invention relates to a rotary shaver.

In a rotary shaver, a disk-shaped outer blade provided with a plurality of slits on the surface and an inner blade provided inside the outer blade relatively rotate to cut a beard that has entered the slit. Some are configured as follows. The inner blade has a disk-shaped base and a plurality of small blades protruding from the base toward the inner surface of the outer blade, and each of the small blades and the inner edge of the slit are like scissors. , The beard is cut off.

Patent Documents

1 and 2 disclose examples of such a rotary shaver.

回転 In this type of rotary shaver, as shown in, for example, FIG. 8 of Patent Document 1, an acute-angled cutting edge is provided at an upper surface end of each small blade. As described in Patent Literature 1, conventionally, it is considered that the angle of the cutting edge is preferably as small as possible. Patent Literature 1 discloses that the angle of the cutting edge is reduced as much as possible while maintaining the rigidity of the small blade. The invention has been disclosed.

JP-A-2005-071002 US Patent Application Publication No. 2013/0145627

However, since the beard has the same hardness as a brass wire or a copper wire, even if the beard is sandwiched between the small blade and the inner edge of the slit, the beard cannot be cut instantaneously. Also, in order to make it easier to catch the beard in the slit, the inner edge of the slit forming one of the blade edges of the scissors is usually curved so that the central portion expands toward the small blade. Due to these circumstances, the beard sometimes escapes radially outward from between the small blade and the inner edge of the slit during cutting, and the beard may not be cut properly.

Therefore, one of the objects of the present invention is to provide a rotary shaver and an inner blade thereof, which prevent the beard from escaping from between the small blade and the inner edge of the slit, thereby suitably cutting the beard. It is in.

The rotary shaver according to the present invention includes a disk-shaped outer blade provided with a plurality of slits on a surface thereof, and an inner blade configured to be relatively rotatable with respect to the outer blade about a center axis of the outer blade as a rotation axis. The outer blade has a cutting edge at a lower end of the inner wall of each of the plurality of slits, and the inner blade has a disk-shaped base and a plurality of blades protruding from the base toward the outer blade. And the cutting edge of each of the plurality of small blades is a rotary shaver having a shape curved toward the inside of each upper surface.

Further, the inner blade of the rotary shaver according to the present invention has a center axis of a disk-shaped outer blade having a blade edge at a lower end of each of a plurality of slits provided on the surface, and the center axis of the outer blade is relatively to the outer blade. An inner blade of a rotary shaver configured to be rotatable, comprising a disk-shaped base, and a plurality of small blades protruding from the base toward the outer blade, each of the plurality of small blades Are the inner blades of the rotary shaver, each of which has a shape curved toward the inside of each upper surface.

According to the present invention, since the cutting edge of the small blade is curved toward the inside of the upper surface, the beard sandwiched between the curved portions is in a state where the escape path is closed. Therefore, it is possible to prevent the beard from escaping from between the small blade and the inner edge of the slit, so that the beard can be suitably cut.

In the rotary shaver or the inner blade thereof, the upper surface of each of the plurality of small blades may be formed in a dog leg shape. According to this, the small blade can be suitably forged by sandwiching the small blade from both sides by the convex first mold and the concave second mold.

It is a figure showing appearance of rotary type shaver 1 by an embodiment of the invention. FIG. 2 is an exploded perspective view showing an outer blade 10 and an inner blade 20 arranged in a head unit 3 shown in FIG. 1. (A) is a top view of the inner cutter 20 shown in FIG. 2, and (b) is a side view of the inner cutter 20 shown in FIG. (A) is a sectional view of one of the plurality of small blades 22 shown in FIGS. 2 and 3, and (b) is a top view of a part of the inner blade 20. (A) and (b) are three-dimensional perspective views of a part of the inner blade 20 viewed from different angles. FIG. 3 is a diagram schematically showing a result of observing a slit 11a shown in FIG. 2 from above with a microscope.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing an appearance of a rotary shaver 1 according to an embodiment of the present invention. As shown in FIG. 1, the rotary shaver 1 includes a substantially cylindrical main body 2 and a head unit 3 installed at an upper end of the main body 2.

The main body 2 is formed of, for example, a resin and has a shape that can be easily held by a user with one hand. The user normally uses the rotary shaver 1 while holding the main unit 2 with one hand and holding the head unit 3 against the chin. Although not shown, inside the main body 2, a motor for rotating the outer blade 10 and the inner blade 20 (see FIG. 2) in the head portion 3, a battery for supplying power to the motor, A circuit board including a control circuit for controlling the operation of the motor; A power button 4 is disposed on a side surface of the main body 2, and the control circuit starts driving the motor when the user presses the power button 4 while the motor is stopped. When the user presses the power button 4, the motor stops driving.

The head portion 3 is a member having a structure in which a disk-shaped outer blade 10 is disposed at each of the three vertices of a triangle, and is connected to the main body 2 via a connection member (not shown). The connection member serves to connect the main body 2 and the head 3 so that the head 3 can swing and move up and down with respect to the main body 2. Further, the connection member is configured to enable the user to replace the head unit 3. The housing of the head unit 3 is formed of, for example, a resin, similarly to the main body 2.

FIG. 2 is an exploded perspective view showing the outer cutter 10 and the inner cutter 20 arranged in the head unit 3. FIG. Although FIG. 1 shows only one outer blade 10 and the inner blade 20 formed inside the outer blade 10, the same applies to the other two outer blades 10 and the corresponding inner blades 20. The outer cutter 10 and the inner cutter 20 each have a disk-shaped portion, and these disk-shaped portions are arranged so as to share a central axis. The outer cutter 10 and the inner cutter 20 are both formed of a rigid body such as stainless steel (more specifically, for example, a martensitic stainless steel represented by SUS420J2, for example).

The inner cutter 20 is configured to be rotatable relative to the outer cutter 10 around the shared central axis as a rotation axis by driving the above-described motor. More specifically, the inner blade 20 is configured to rotate in the illustrated rotation direction R2, and the outer blade 10 is configured to rotate in the illustrated rotation direction R1 (the direction opposite to the rotation direction R2) with the shared central axis as the rotation axis. You. Therefore, the rotation speed of the inner cutter 20 with respect to the outer cutter 10 is a speed obtained by adding these rotation speeds (the rotation speed with respect to the main body 2).

The shape of the outer cutter 10 will be specifically described. The surface of the outer cutter 10 corresponding to the bottom of the bottomed cylinder (hereinafter referred to as the “upper surface” of the outer cutter 10) includes a plurality of slits 11a to 11d. Are provided. Each of the plurality of slits 11a to 11d penetrates the upper surface of the outer blade 10, and although not shown, has a cutting edge at the lower end (inner edge) of each inner wall. The angle of the cutting edge is, for example, 90 °. The upper surface of the outer cutter 10 is divided into three regions by two concentric circles centered on the center axis of the outer cutter 10, and the outermost region (hereinafter, referred to as “outer annular region”) has a slit.

Slits

11c and 11d are formed in the second region from the outside (hereinafter referred to as "inner annular region") 11a and 11b.

The plurality of slits 11a are substantially linear grooves formed to be slightly inclined with respect to the radial direction from the side surface of the outer cutter 10 to the inner periphery of the outer annular region, and are provided at equal intervals along the circumferential direction. Can be Specifically, when viewed in the rotation direction R1, the end on the side surface of the outer cutter 10 is located behind the end on the inner peripheral side of the outer annular region. In addition, each slit 11a is not strictly a straight line, but is formed so as to be curved so that the center portion slightly swells forward in the rotation direction R1 (rear in the relative rotation direction). The specific number of the slits 11a is, for example, 45, and in this case, the installation interval between the slits is 8 °.

The plurality of slits 11b are substantially linear grooves provided one by one between two adjacent slits 11b. Each slit 11b is provided along the adjacent slit 11a, and therefore has the same inclined and curved shape as the slit 11a. However, the end of the slit 11b located on the inner peripheral side of the outer annular region is located slightly outside (the position close to the side surface of the outer blade 10) that of the slit 11a. It is shorter than the entire length of the slit 11a.

The plurality of slits 11c are substantially linear grooves formed slightly inclining with respect to the radial direction from the outer periphery of the inner annular region to the inner periphery of the inner annular region. The plurality of slits 11c are arranged, for example, in units of sets each including four, and each set is provided at equal intervals along the circumferential direction. The specific number of sets of the slits 11c is, for example, five, and in this case, the installation interval of each set is 72 °. Each slit 11c has the same inclined and curved shape as the slit 11a, and is arranged in each set at equal intervals along the circumferential direction.

The plurality of slits 11d are a plurality of circular holes arranged between sets of the slits 11c, and are arranged in a zigzag manner in a circumferential direction between two sets adjacent to each other.

Next, the shape of the inner blade 20 will be specifically described. The inner blade 20 has a disk-shaped base 21 and a plurality of small blades 22 protruding from the base 21 toward the outer blade 10. Be composed. Each of the small blades 22 has an upper surface 22a which is smoothed so as to be parallel to the base 21.

スプリング A spring (not shown) is provided between the inner blade 20 and the housing of the head unit 3 (see FIG. 1). The spring plays a role of pressing the upper surface 22a of the small blade 22 against the lower surface of the outer blade 10 by urging the inner blade 20 upward (toward the outer blade 10). However, if the pressing force is too strong, the rotation of the inner blade 20 is hindered, so that the biasing force of the spring is set to be weak.

FIG. 3A is a top view of the inner cutter 20, and FIG. 3B is a side view of the inner cutter 20. As shown in these figures, the plurality of small blades 22 are arranged in two rows along the circumference of the base 21. The inner row corresponds to the

slits

11c and 11d of the outer blade 10, and has a configuration in which seven small blades 22 are arranged at equal intervals. The outer row corresponds to the

slits

11a and 11b of the outer blade 10, and has a configuration in which 14 small blades 22 are arranged at equal intervals.

小 Each of the small blades 22 is formed so as to project obliquely at an angle θ from the surface of the base 21. θ is the angle between the rotation direction R2 and the direction in which the small blades 22 protrude, and is, for example, 65 °. Each of the small blades 22 is formed by forming a substantially U-shaped groove in a circular stainless steel serving as the base 21, and processing the resulting protrusion. Typically, the protrusions are formed by forming a side surface shape (specifically, shapes of

surfaces

22b and 22c described later) using forging, bending the root to an angle θ, and applying heat treatment. Is performed by smoothing the upper surface 22a so as to be parallel to the surface of the base 21, but the order of these steps may be appropriately changed.

Here, in the smoothing, the shape of the upper surface 22a of the small blade 22 is formed along the lower surface of the outer blade 10 (that is, the clearance between the upper surface 22a of the small blade 22 and the lower surface of the outer blade 10 is constant). And is typically performed by polishing. However, when the lower surface of the outer cutter 10 is a curved surface or the like, electric discharge machining may be used instead of polishing. That is, a shape electrode having a shape corresponding to the shape of the lower surface of the outer blade 10 is formed, and the shape of the lower surface of the outer blade 10 is transferred to the upper surface 22a of the small blade 22 by performing electric discharge machining using the shape electrode. You may do it.

FIG. 4A is a sectional view of one of the plurality of small blades 22, and FIG. 4B is a top view of a part of the inner blade 20. FIGS. 5A and 5B are three-dimensional perspective views of a part of the inner blade 20 viewed from different angles. Hereinafter, the shape of the small blade 22 will be specifically described with reference to these drawings. The small blades 22 not shown in FIGS. 4 and 5 have the same shape as the small blades 22 shown.

First, referring to FIG. 4A, each of the small blades 22 has a blade edge 23 at one end of the upper surface 22a. The cutting edge 23 is configured by a leading edge of the upper surface 22a in the rotation direction R2 (an edge having an angle θ formed by the upper surface 22a and the surface 22b of the small blade 22 positioned forward in the rotation direction R2).

Next, referring to FIG. 4B, the cutting edge 23 formed by the leading edge of the upper surface 22a in the rotation direction R2 has a shape curved toward the inside of the upper surface 22a. On the other hand, the edge of the rear end of the upper surface 22a in the rotation direction R2 has a shape that is curved toward the outside of the upper surface 22a. Accordingly, the entire upper surface 22a of each of the small blades 22 is formed in a dog-leg shape (curve shape) having a central portion curved rearward in the rotation direction R2. The line segment A connecting both ends of the cutting edge 23 of each small blade 22 is parallel to the radial direction of the inner blade 20. The minimum radius of curvature of the curved cutting edge 23 is set to a value sufficiently larger than the radius of the beard as understood from FIG.

Next, referring to FIGS. 5A and 5B, as understood from these figures, the surface 22 b of the small blade 22 has a horizontally curved shape in the same shape as the blade edge 23 from the upper end to the lower end. Have. On the other hand, the surface 22c of the small blade 22, which is located rearward in the rotation direction R2, has a rough tendency to be curved from the upper end to the lower end in a horizontal direction in the same shape as the rear end edge of the upper surface 22a in the rotation direction R2. It has a concave shape 24 in the middle. The concave portion 24 is for releasing a small piece that may be generated when cutting the beard.

FIG. 6 is a view schematically showing the result of observing the slit 11a from above with a microscope. As described above, since the slit 11a is inclined with respect to the radial direction and has a curved shape, a line segment connecting the inner edge of the slit 11a and both ends of the cutting edge 23 of the small blade 22 when viewed with a microscope. A is not parallel, but is oblique as shown in FIG. Thus, when the outer blade 10 rotates in the rotation direction R1 and the inner blade 20 rotates in the rotation direction R2, the blade edge 23 of the small blade 22 and the inner edge of the slit 11a gradually overlap from the end near the common center axis, As a result, cutting of the beard H like scissors is realized. The same applies to the

slits

11b and 11c.

Here, since the beard H is very hard (for example, having the same hardness as a brass wire or a copper wire), even if the beard H is sandwiched between the cutting edge 23 and the inner edge of the slit 11a, the beard H is instantaneous. Cannot be cut. In addition, since the inner edge of the slit 11a and the line segment A connecting both ends of the cutting edge 23 of the small blade 22 are oblique, if the cutting edge 23 is formed in a straight line, cutting is performed. While time is required, the beard H may escape in the illustrated B direction. The tendency of the escape is remarkable when the center of the inner edge of the slit constituting one of the cutting edges of the scissors is curved so as to expand toward the small blade 22, as in the slits 11a to 11c.

According to the present embodiment, on the other hand, the blade 23 is curved toward the inside of the upper surface 22a, so that the beard H can be captured in the curved portion of the blade 23 as shown in FIG. Since the beard H thus captured is in a state where the escape path is closed, the beard is prevented from escaping from between the small blade 22 and the inner edge of the slit 11. Therefore, according to the present embodiment, it is possible to suitably cut the beard H.

As described above, according to the rotary shaver 1 and the inner blade 20 of the present embodiment, the beard H can be prevented from escaping from between the small blade 22 and the inner edge of the slit 11, so that the beard H The cutting can be suitably performed.

Further, according to the rotary shaver 1 and the inner blade 20 of the present embodiment, the upper surface 22a (and the horizontal cross section of each of the small blades 22) of each of the plurality of small blades 22 is formed in a dogleg shape. In the forging process of the small blade 22, when the small blade 22 is sandwiched from both sides by the convex first mold and the concave second mold, the recess of the surface 22b can be suitably released to the surface 22c side. it can. Therefore, it is possible to suitably forge the small blade 22.

Furthermore, according to the rotary shaver 1 and the inner blade 20 according to the present embodiment, since the blade edge 23 is curved inward, the upper surface 22a of the small blade 22 is caught by the outer blade 10 and rotates well. It can also be prevented from disappearing.

Further, according to the rotary shaver 1 and the inner blade 20 of the present embodiment, in addition to the blade 23 being curved, the minimum radius of curvature of the curved blade 23 is set to a value larger than the radius of the beard H. Since the setting is made, it is also possible to obtain an effect that the cutting resistance is dispersed and a better cutting result can be obtained.

As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to these embodiments at all, and the present invention can be implemented in various modes without departing from the gist thereof. Of course.

DESCRIPTION OF SYMBOLS 1 Rotary shaver 2 Main body 3 Head part 4 Power button 10

Outer blade

11, 11a-11d Slit 20 Inner blade 21 Base 22 Small blade

22a Upper surface

22b, 22c of small blade 22 Surface 23 of small blade 22 Cutting edge of small blade 22 24 Concavity H on surface 22c Beard of user

Claims

A disk-shaped outer blade having a plurality of slits on its surface,
An inner blade configured to be rotatable relative to the outer blade with the center axis of the outer blade as a rotation axis,
The outer blade has a cutting edge at the lower end of the inner wall of each of the plurality of slits,
The inner blade has a disk-shaped base, and a plurality of small blades protruding from the base toward the outer blade,
The cutting edge of each of the plurality of small blades has a shape curved toward the inside of each upper surface,
Each of the plurality of slits is inclined such that an outer end is located forward of an inner end when viewed in a rotational direction of the inner blade with respect to the outer blade, and swells rearward in the rotational direction. Has a shape curved with a radius of curvature larger than the cutting edge of each of the plurality of small blades,
Each of the plurality of small blades has a shape formed by bending a root of a protrusion generated by forming a groove in the base in a direction opposite to the rotation direction,
Rotary shaver.
The upper surface of each of the plurality of small blades is formed in a dog leg shape,
The rotary shaver according to claim 1.