JPS6350032B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an outer cutter for a rotary electric shaver.

Generally, in this type of electric shaver, the circumferential speed of the cutting edge of the inner cutter during rotation is faster as it approaches the outer end, so the hair introduced into the hair introduction hole of the outer cutter that corresponds to the rotation trajectory on the outer end side is is easily ejected without being sheared by the inner cutter. Therefore, an outer cutter is required that can effectively maintain the captured shearing effect regardless of the circumferential speed of the cutting edge of the inner cutter.

For this reason, we have already arranged a group of slits for capturing long hairs oriented in the spiral direction on the inner circumference of the outer blade base.
A first group of curved ribs along a large number of arcuate curves curving in the rotational direction of the inner cutter and a second group of curved ribs along a number of arcuate curves curving in the opposite direction are intersected on the outer periphery. By forming similar-shaped hair introduction holes according to the area of each region in the numerous approximately rhombic divided regions formed by intersecting the rib group, the blade is excellent regardless of the circumferential speed of the inner and outer ends of the inner cutter. A device that can exhibit a trapping shear effect has been proposed.

However, with the above structure, the slit for capturing long hair faces only in one direction, so although it has good capture properties for curly hair and long hair in that direction, it does not capture curly hair that curves in the opposite direction. There are bad drawbacks. Although the above problem can be solved to some extent by arranging the slits in the radial direction of the outer cutter base, in that case, there is a risk that the inner cutter may slide in a pinching manner.

This invention was made in view of the above circumstances, and the slit group in the inner peripheral part of the outer cutter base is arranged in multiple rows in the radial direction, and the orientation of the slits in each row is deviated from the radial direction. By setting the slits in the direction that intersects the direction of the slits in the adjacent rows, the inner blade can slide smoothly and can efficiently capture long or curly hair regardless of the curved direction. The purpose is to provide outer blades for electric razors.

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

1 and 2 are a sectional view and a plan view showing an example of a dome-shaped outer blade of a rotary electric shaver according to the present invention. It is a blade base, and is formed, for example, by electroforming.

A large number of substantially diamond-shaped hair introduction holes 2 are formed in the outer circumferential portion 1a of the outer cutter base 1, and a group of slits 30 are provided in the inner circumferential portion 1b.

The hair introduction hole 2 is formed as follows. A first group of curved ribs along a large number of arcuate curves extending from the center P side of the base body 1 toward the outer peripheral edge Q side, for example, an involute curve developed toward the rotation direction of the inner cutter 4 (direction of arrow a). 5 and a second curved rib group 6 along an involute curve developed in the opposite direction. A substantially diamond-shaped hole is formed, and this is used as the hair introduction hole 2.

The slit group 30 has a plurality of rows 3 in the radial direction.
It is divided and arranged into 0.30 ₁ to 30 ₄ .
Furthermore, the orientation of the slits 3 ₁ to 3 ₄ in each row 30 ₁ to 30 ₄ is offset from the radial direction, and
0 ₁ , 30 ₃ slits 3 ₁ , 3 ₃ are adjacent rows 30
It is set in a direction intersecting the slits 3 ₂ and 3 ₄ of _{No. 2} and 30 ₄ . 8 is an outer blade holder.

In the above configuration, the approximately diamond-shaped hair introduction hole 2 on the outer circumferential portion 1a side is located closer to the outer circumferential side, the angle α of the hair receiving corner portion 2a becomes smaller as shown in FIG. 3 (α ₁ > αn). In other words, even if the circumferential speed of the outer end of the cutting edge of the inner cutter 2 is high, the hair can be reliably captured at a small angle α, so that the hair is not thrown out from the hair introduction hole 2 and is effectively is cut off.

Also, because the first curved rib group 5 and the second curved rib group 6 intersect, when this outer blade is pressed against the skin, the pressed part is spread evenly in all four directions. Since it can be stretched, the shearing action described above is performed smoothly.

In particular, since the slit group 30 is located in a portion of the inner peripheral portion 1b of the outer blade base 1 that is likely to contact the skin,
Long hair and curly hair are easily captured, and the orientation of the slits 3 ₁ , 3 ₃ in each row 30 ₁ , 30 ₃ of the slit group 30 intersects the orientation of the slits 3 ₂ , 3 ₄ in the adjacent rows 30 ₂ , 30 ₄ . Therefore, even if long hair or curly hair extends in various directions, the slits in one of the rows 3 ₁
~3 ₄ can be captured efficiently. Furthermore, each column 30 ₁
Since the slits 3 ₁ to 3 ₄ of ~30 ₄ are offset with respect to the radial direction (direction of arrow b in Figure 4), the inner cutter 4
The sliding motion is relatively smooth. Moreover, since the directions of the slits 3 ₁ to 3 ₄ in each of the rows 30 ₁ to 30 ₄ intersect, it is possible to prevent the outer cutter base from being cracked in the radial direction due to unreasonable stress.

Here, the mutual opening direction relationship of each slit 3 ₁ , 3 ₂ , 3 ₃ , 3 ₄ will be explained with reference to FIG.

A virtual center line r is drawn in the radial direction from the center P of the outer cutter, and each slit 3 ₁ , 3 ₂ , 3 ₃ ,
The intersection angles θ ₁ , θ ₂ , θ ₃ , θ ₄ between the major axes f ₁ , f ₂ , f ₃ , f ₄ of 3 ₄ and the center line r are +22.5°, −8°, and +18°. ,
It is varied by -15°.

That is, the innermost slit row 30 ₁ and the third slit 30 ₃ have a positive angle that is the same direction as the rotational direction a of the inner cutter, and the second and fourth slit rows 30 ₂ ,
30 ₄ is a negative angle. Further, while the angle of the third slit row 30 ₃ is smaller than that of the first slit row 30 ₁ , the angle of the fourth slit row 30 ₄ is increased toward the negative side compared to the second slit row 30 ₂ .

By configuring as described above, not only can the opening direction of the slits be alternately changed, but also the spaced slit rows 30 ₁ , 30 ₃ and 30 ₂ in the same direction,
The angle is also changed between 30 and ₄ , especially,
The first hole opening direction is directed toward the rotational direction a side of the inner cutter.
When the slit row 30 ₁ and the third slit row 30 ₃ are in the same direction as the rotation direction a, the outer circumferential side is closer to the center line r, that is, the angle is closer to O, and the second slit row 30 ₂ and the fourth slit row ₃₀₄ are set in a direction that gradually widens toward the minus side with respect to the center line r, thereby improving the cutting efficiency in the central portion.

In addition, if the first curved rib group 5 and the second curved rib group 6 are along an arcuate curve extending from the center P side of the outer cutter base body 1 toward the outer peripheral edge Q side, the above-mentioned involute curve It is not limited to those in line with the above.

Further, in the above embodiment, the explanation is given using a dome-shaped outer cutter as an example, but it is of course applicable to a so-called donut-shaped outer cutter in which the center portion of the outer cutter base 1 is recessed. be.

As described above, according to the present invention, hair can be captured regardless of the circumferential speed of the inner cutter, and by arranging the slit group on the inner circumference in multiple rows in the radial direction, long hair and curly hair can be captured. It is possible to provide an outer blade for a rotary electric shaver that has improved gripping properties and enhanced strength.

[Brief explanation of the drawing]

1 and 2 are a cross-sectional view and a plan view, respectively, showing an example of the outer blade of the rotary electric shaver according to the present invention, FIGS. 3 and 4 are explanatory diagrams of the function of the outer blade, and FIG. FIG. 3 is an explanatory diagram of the opening direction of the slit. _DESCRIPTION OF SYMBOLS 1...Outer blade base, 1a...Outer periphery, 1b...Inner periphery, 2...Hair introduction hole, _31-34 ...Slit,
4...Inner blade, 5...First curved rib group, 6...Second curved rib group, 7...Divided area, 30...Slit group, ₃₀₁ to ₃₀₄ ...Slit row.

Claims (1)

[Claims] 1 A group of slits 30 for capturing long hair are provided on the inner circumferential portion 1b of the outer cutter base 1, and a group of slits 30 for capturing long hair are provided on the outer circumferential portion 1a, extending from the center P side of the outer cutter base 1 toward the outer circumferential edge Q side, and the inner cutter 4 A large number of curved ribs formed by the intersection of a first group of curved ribs 5 along a number of arcuate curves curving in the rotation direction of the ribs and a second group of curved ribs 6 along a number of arcuate curves curving in the opposite direction. In the outer blade of a rotary electric shaver, the slit group 30 is arranged in a plurality of rows 30 in the radial direction, and the hair introduction holes 2 are formed in a similar shape according to the area of each region 7, and are located in the approximately rhombic divided regions 7 of the rotary electric shaver. ₁ to 30 Divide into ₄ , each row 30 ₁
The orientation of the slits 3 ₁ to 3 ₄ of 30 ₄ is offset from the radial direction, and the adjacent rows 30 ₁ ,
30 ₃ , 30 ₂ , 30 ₄ slits 3 ₁ , 3 ₃ , 3 ₂ ,
The outer blades of a rotary electric shaver are set with 3 and ₄ facing in a direction that intersects with each other.