JPS6232532Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a rotary electric shaver, which prevents the generation of sliding force in the axial direction between the rotary inner cutter and the outer cutter covered therewith. , the directionality of the shaving effect due to the difference in the direction of the beard hair entering from the beard introduction hole of the outer blade is eliminated.

(Background of the invention) A rotary electric shaver has a rotary inner cutter with an outer cutter covered with a rotary inner cutter that rotates around its axis. As shown, a rotary inner cutter 1' in which blades 2' are arranged parallel to the axis 1' over the entire circumferential barrel surface is known. However, as shown in FIG. 8, when shaving, the rotary inner cutter 1' is affected by an external force from the skin that is applied to the outer cutter 3', and the outer cutter 3' moves as shown by the dotted line using the blades 2' and 2' as fulcrums. The blade 2' is easily deformed inwardly.
The outer cutter 3' may be damaged due to collision between the outer cutter 3' and the outer cutter 3'.
The wear of the cutting edge caused a decrease in cutting power. Therefore, as shown in FIG. 9, it has been proposed that the blade 5' of the rotary inner cutter 4' is formed at a helix angle θ with respect to the axis l. However, in this case, a sliding force _P1 in a direction perpendicular to the direction in which the blades 5' are formed is generated on the sliding surfaces of the rotary inner cutter 4' and outer cutter 6', which rotate at high speed. There was a problem in that it was pulled in the direction of action of the sliding contact force _P1 , causing tensile stress and being easily damaged. In addition, an axial component force P ₂ of the sliding contact force P ₁ acts on the rotary inner cutter 4', and an unreasonable load is applied to the bearing etc., causing the inner cutter 4'
There was a problem that prevented smooth rotation. Furthermore, since all of the blades 5' of the rotary inner blade 4' are formed in a single direction (downward left direction), the beard hair 7' that enters from the same direction as the direction in which the blades 5' are formed gets caught up in the blades 5'. However, if the beard hair 8' enters from the direction perpendicular to the direction in which the blade 5' is formed, especially if the beard hair 8' is long hair,
There was a problem with the blade being thrown back and only the tip being sheared, making it impossible to get a close shave.

(Purpose of the invention) An object of the invention is to provide a rotary electric shaver that eliminates the problems of the conventional shaver described with reference to FIG. In other words, the present invention prevents the generation of an axial component of sliding force between the rotary inner cutter, which rotates at high speed around its axis, and the outer cutter covered with it, which can cause damage to the outer cutter. The first object of the present invention is to provide a rotary electric shaver that can prevent the above-mentioned problems. A second object of the present invention is to provide a rotary electric shaver that can eliminate the directionality of the shaving effect caused by the difference in the direction of the beard hair entering through the beard introduction hole of the outer blade.

(Summary of the invention) In the invention, the circumferential body surface of the rotary inner cutter, which is covered by the outer cutter in sliding contact, is divided into a plurality of parts by virtual circumferential lines. Then, with the virtual circumference line as the axis of symmetry, the left region blade and the right region blade, which are given a helix angle with respect to the axis of the rotary inner cutter, are symmetrically formed downward to the right or downward to the left. When the blade rotates in sliding contact with the inner surface of the outer cutter, the axial components of the sliding force generated between the left area blade, the right area blade, and the outer blade are made to cancel each other out. With this configuration, it is possible to prevent tensile stress from being generated in the outer cutter in the lateral direction, that is, in the axial direction of the rotary inner cutter, causing damage during shaving, and to prevent unnecessary loads from being applied to the bearing of the rotary inner cutter. There is. Furthermore, by forming left region blades and right region blades with different formation directions on the circumferential body surface of the rotary inner cutter, the directionality of the shaving effect due to the difference in the direction of entry of beard hair is eliminated.

(Example) Hereinafter, an example of the present invention will be explained along with the drawings.

FIG. 1 is a front view of a cylindrical rotary inner cutter 1, which is driven by a motor (not shown) and rotates in the circumferential direction about its axis l. A large number of blades 2 are formed protrudingly on the circumferential body surface of the inner cutter 1, and the circumferential body surface of the inner cutter 1 is divided into left and right halves by an imaginary circumferential line NA. Among them, the left area blade 2a formed in the left half with the circumferential line NA as the axis of symmetry has a torsion angle θ with respect to the axis l.
The right region blade 2b is formed downward to the right with
It is formed downward to the left with double edges 2a, 2.
b is formed symmetrically with respect to the circumferential line NA as an axis of symmetry.

FIG. 2 is a developed view of the outer cutter 3 that is covered in sliding contact with the rotary inner cutter 1, and shows the hair introduction hole 3a of the outer cutter 3.
are formed symmetrically with respect to the circumferential line NA as an axis of symmetry so as to correspond to the direction in which the left and right region blades 2a and 2b are formed, and have an inclination angle θ that is the same as the torsion angle θ.

This rotary electric shaver has the above-mentioned configuration, and when the outer cutter 3 is covered with the rotary inner cutter 1 and the rotary inner cutter 1 is rotated at high speed in the circumferential direction around the axis l, the left region cutter 2a and A downward sliding force F 1 to the left is generated between the left half of the outer cutter 3 in a direction perpendicular to the cutter 2a, and a sliding force _F1 is generated between the left half of the outer cutter 3 and the right region cutter 2b.
A sliding contact force F ₂ downward to _{the right} is generated between the right half of
Since the axial components of F ₁ and sliding contact force F ₂ cancel each other out, the outer cutter 3 will not be damaged due to tensile stress in the axis l direction, and the reaction force will be applied to the bearing of the rotary inner cutter 1. The rotation of the inner cutter 1 will not be hindered due to unnecessary load. Furthermore, the beard hair 4 that has entered the left area blade 2a from the direction perpendicular to the direction in which it is formed is bounced back by the cutting edge of the blade 2a as described above and remains unshaved. By moving the
This beard hair 4 is also introduced from the right half of the outer blade 3, enters the right area blade 2b in the forming direction of the blade 2b, and is reliably sheared from the root by the blade 2b. In this way, the left and right area blades 2a, 2b
By forming symmetrically with respect to the virtual circumferential line NA, the beard hair 4 entering from the beard introduction hole 3a
It is possible to eliminate the directionality of the shaving effect due to the difference in the approach direction of the hair.

(Other Embodiments) In FIG. 3, there are three virtual circumferential lines NA, NA', NA'' of the rotary inner cutter 5, and the left and right area blades 6a, 6b are arranged with the central virtual circumferential line NA as the axis of symmetry. The left and right virtual circumferential lines NA′,
Further left and right area blades 6a′, 6 with NA″ as the axis of symmetry
a″, 6b′, 6b″ are formed symmetrically. In this way, the left and right area blades 6a', 6a'', 6 are symmetrically arranged with respect to the plurality of virtual circumferential lines NA, NA', NA'', respectively.
If b', 6b'' are formed, there is an advantage that the directionality of the shaving effect can be further eliminated.

(Other Embodiments) FIG. 4 shows still another embodiment of the present invention, in which the blades 8 of the rotary inner cutter 7 are arranged along virtual circumferential lines.
Left and right area blades 8a' and 8b' are formed symmetrically with a torsion angle θ ₁ with NA as the axis of symmetry, and a torsion angle θ is formed at both left and right ends of these left and right area blades 8a' and 8b'.
The area blades 8a″, 8 are bent at ₂ and connected in series.
b''.The helix angle θ ₁ of the left and right area blades 8a', 8b' is the torsion angle θ ₂ of the area blades 8a'', 8b''.
Although the axial length d1 of the left and right region blades 8a' and 8b' is longer than the axial length d2 of the region blades 8a'' and 8b'', the blade 8 as a whole is virtual. It is formed symmetrically with the circumferential line NA as the axis of symmetry.

Next, an example of a method for manufacturing a rotary inner cutter will be described.

In FIG. 5, A and B are cylindrical rotary inner cutter halves that have symmetrical helix angles to form left and right region blades a and b, and one inner cutter half B has an end surface. A cylindrical protrusion 8 is provided protrudingly, and when this protrusion 8 is inserted into the other inner cutter half A, both A,
B are combined to form a rotary inner cutter C. D is a hollow core rod, the circumferential surface of which is formed with unevenness in the length direction, and a flat receiving hole at the end for fixing the fixed piece 10 of the rotating shaft F.
D′ is formed. As shown in Figure 6, by inserting and fixing this core rod D into the rotary inner cutter C after pouring an adhesive E such as resin, the two halves A and B are firmly integrated. . A fixed piece 10 is attached to the end of the rotating shaft F, and a gear 9 through which rotation is transmitted from the motor is attached.The shaft F is inserted into the core rod D, and the fixed piece 10 is inserted into the receiving hole of the core rod D. The assembly is completed by fitting it into D′.

According to this method, a rotary inner cutter having a blade having a symmetrical helix angle can be easily and strongly manufactured. This example describes the case of manufacturing the rotary inner cutter 1 of the first embodiment, but the rotary inner cutters 5 and 7 of the second and third embodiments are also manufactured in the same manner as in this example. Each blade 6a', 6a'', 6b', 6b'', 8a', 8a'', 8
b′, 8b″ are formed separately in advance,
It goes without saying that it can be manufactured later by integrating as in the case of this example.

(Effect of the invention) As explained above, according to the invention, the axial component forces of the sliding forces F ₁ and F ₂ generated between the left area blade 2a and the right area blade 2b and the outer blade 3 are canceled out. This prevents damage due to tensile stress acting on the outer cutter 3 in the direction of the axis L during shaving, or unnecessary load acting on the bearing of the rotary inner cutter 1, which obstructs the rotation of the rotary inner cutter 1. You can prevent it from happening. Further, by forming the left and right region blades 2a and 2b symmetrically, the directionality of the shaving effect with respect to the direction in which the beard hair 4 enters from the beard introduction hole 3a is eliminated, and hair can be reliably shaved.

[Brief explanation of drawings]

The figure shows an embodiment of the present invention.
Figure 2 is a front view of the rotary inner cutter, Figure 2 is a developed view of the outer blade, Figure 3 is a front view of another embodiment of the present invention, Figure 4 is a front view of yet another embodiment, and Figure 5. and FIG. 6 are a perspective view and a cross-sectional view, respectively, during manufacture, and FIGS. 7, 8, and 9 are a front view, a side view, and a front view, respectively, of conventional products. 1, 5, 7...Rotary inner blade, 2a, 6a,
6a'', 8a, 8a'...left area blade, 2b, 6b, 6
b'', 8b, 8b'...Right area blade, 3...Outer blade, 3a
...beard introduction hole, θ, θ ₁ , θ ₂ ... twist angle,
l...Axis line, NA, NA', NA''...Virtual circumference line.

Claims (1)

[Scope of utility model registration request] The rotary inner cutter 1 is equipped with a rotary inner cutter 1 that rotates in the circumferential direction around an axis l, and an outer cutter 3 in which a hair introduction hole 3a is formed and covered by sliding contact with the rotary inner cutter 1. Virtual circumference line on circumferential surface
The left region blade 2a and the right region blade 2b are divided into a plurality of pieces by NA, and the left region blade 2a and the right region blade 2b are formed symmetrically with the virtual circumferential line NA as an axis of symmetry and a torsion angle θ is given to the axis l. A rotary electric shaver characterized in that the axial components of the sliding forces F ₁ and F ₂ generated between the outer cutter 3 and the outer cutter 3 are set so as to cancel each other out.