JP7837073B2 - Thinning scissors - Google Patents

Description

This invention relates to thinning shears.

A conventional thinning shear is known, comprising a comb blade, a rod blade, and a pivot that rotatably connects the comb blade and the rod blade, wherein the comb blade has multiple comb teeth that protrude along the tangential direction of its rotational trajectory. This thinning shear allows for the cutting of hair located between the protruding ends of the comb teeth and the rod blade, while simultaneously thinning the hair located between adjacent comb teeth, thereby adjusting the volume of hair in that area without changing its length.

As an improvement on this, thinning shears are known in which multiple grooves (three or more) are formed on the blade, with varying spacing between adjacent grooves and multiple grooves of different depths (see, for example, Patent Document 1).

According to the thinning shears described in the above-mentioned literature, it becomes possible to securely cut hair located between the protruding ends of the comb teeth and the straight blade by engaging it in the grooves. Furthermore, by intentionally creating variations in the density and depth of the grooves, it is possible to achieve a natural finish by varying the way the hair is thinned and cut.

On the other hand, the thinning shears described in the above-mentioned literature require precise relative alignment between the grooves formed on the straight blade and the comb teeth formed on the comb blade. Therefore, high precision is required in the connection between the straight blade and the comb blade, as well as in the formation of the comb teeth and grooves.

Japanese Patent Publication No. 2002-292160

The present invention aims to provide thinning shears that securely cut hair located between the protruding ends of the comb teeth and the blade by engaging them with grooves, while also allowing for natural variations in the thinning and cutting state, and not requiring high precision in the formation and assembly of the comb teeth and grooves.

To solve the above problems, the device comprises a comb blade, a rod blade, and a pivot that rotatably connects the comb blade and the rod blade, wherein the comb blade has a plurality of comb teeth that protrude along the tangential direction of its rotational trajectory, and at least some of the comb teeth formed on the comb blade have one or more grooves formed on their protruding end faces that are recessed in the direction opposite to the direction of protrusion and along the thickness direction of the comb blade, and at least one set of comb teeth is provided in which the number of grooves formed on each of the plurality of comb teeth is different from each other, or at least one set of comb teeth is provided in which a comb tooth with a groove is formed and a comb tooth without a groove is formed, and the comb blade is provided with a decreasing region in which the density of the grooves gradually decreases from the cutting edge toward the base of the blade, and an increasing region in which the density of the grooves gradually increases .

The comb may be configured with multiple sets of comb teeth, each having a different number of grooves, as well as multiple sets of comb teeth with and without grooves.

The comb blade may be provided with multiple decreasing regions where the density of grooves gradually decreases from the tip to the base of the blade, and increasing regions where the density of grooves gradually increases.

The comb teeth may be curved to follow the rotational trajectory of the comb blades.

The protruding ends of the comb teeth may be enlarged portions with a larger cross-sectional area compared to other parts, and one or more grooves may be provided on the protruding end face of the enlarged portion , biased toward the cutting edge .

Because grooves are provided on the comb teeth, high precision is not required in shaping the blade side. Furthermore, by providing at least one combination of grooved comb teeth with different numbers of grooves, or at least one combination of grooved and ungrooved comb teeth, it is possible to introduce natural variations in the thinning and cutting state.

This is a front view of thinning shears to which the present invention is applied. Figure 1 is a magnified front view of the blade portion of the thinning shears. (A) is a front view of the comb teeth, and (B) is a view of (A) from the perspective of arrow B. This is an enlarged front view of the cutting edge side of a pair of blades. This is an enlarged front view of the cutting edge side of a pair of thinning scissors according to another embodiment.

Figure 1 is a front view of thinning shears to which the present invention is applied. The thinning shears (thinning scissors) shown in the figure comprise a pair of blades 1 and 2, handles 3 and 4 integrally formed on each blade 1 and 2 and extending in the direction opposite to the cutting edge (tip) of each blade 1 and 2, ring-shaped finger rings 6 and 7 integrally formed on the base ends of each handle 3 and 4, opposite to the blades 1 and 2, and a screw portion (pivot portion) 8 that rotatably connects the pair of blades 1 and 2 at their base end portions.

For convenience, in this example, we define the thickness direction of blades 1 and 2 as the front-to-back direction, and the overall length direction of the thinning shears as the left-to-right direction. The following explanation will proceed based on this premise.

One of the pair of blades 1 and 2 is a comb-shaped blade 1, and the other is a straight blade 2. Similar to typical thinning shears, the comb blade 1 is a stationary blade, and the straight blade 2 is a moving blade. The finger hole 6a formed in the ring 6 on the handle 4 side, which extends integrally from the straight blade 2, is typically for the thumb. On the other hand, the finger hole 7a formed in the ring 7 on the handle 3 side, which extends integrally from the comb blade 1, is typically for the ring finger or middle finger.

On the side of the comb blade 1 closest to the ring 7, a rod-shaped finger hook 9 is integrally formed, protruding from the outer edge of the ring shape, away from the tip of the comb blade 1 and away from the other ring 6. The little finger is hooked onto this finger hook 9, and the ring finger is inserted through the finger hole 7a of the ring 7, or the ring finger is hooked onto the finger hook 9, and the middle finger is inserted through the finger hole 7a of the ring 7.

On the side of the rod blade 2 closest to the ring 6, a rod-shaped hit point 11 is integrally formed, protruding from the outside of the ring shape towards the ring 7 on the comb blade 1 side. When switching from an open state to a closed, overlapping state of the pair of blades 1 and 2, the hit point 11 on the ring 6 collides with the other ring 7, generating an impact sound, allowing the user to recognize that the thinning scissors will not close any further.

The screw portion 8 is a conventionally known connector that links the comb blade 1 and the rod blade 2. While the details of its configuration are omitted, it includes, for example, a male screw, a female screw, and a bearing. The male screw and each of its male screws are inserted into connecting holes drilled in the pair of blades 1 and 2, respectively. With the bearing interposed between them, the two are screw-engaged, thereby rotatably connecting the pair of blades 1 and 2.

Figure 2 is an enlarged front view of the blade portion of the thinning shears shown in Figure 1. The cutting edge 2a of the straight blade 2 has a shape where the central part bulges in an arc relative to the tip and base of the blade, improving cutting performance.

The comb blade 1 has multiple comb teeth 12 arranged in its longitudinal direction. Each comb tooth 12 is formed to protrude along the tangential direction of the rotational trajectory of the comb blade 1. More specifically, the shape of the comb teeth 12 is curved in an arc along the rotational trajectory of the comb tooth 12.

The imaginary line L, formed by connecting the tips of the multiple comb teeth 12, has a shape similar to the cutting edge 2a of the rod blade 2, with its central portion bulging in an arc shape relative to both the cutting edge and the base. Furthermore, the distance from the threaded portion 8 at the cutting edge of the comb teeth 1 is set to be slightly shorter than the distance from the threaded portion 8 at the cutting edge of the rod blade 2.

Figure 3(A) is a front view of the comb teeth, and (B) is a view taken along arrow B in (A). As shown in Figures 2 and 3, an enlarged portion 13 is integrally formed on the protruding end (tip side) of the comb teeth 12. This enlarged portion is longer in the overall length direction of the comb teeth 1 than the middle and base portions, and its cross-sectional area is enlarged. The tip surface of this enlarged portion 13 (the protruding end surface of the comb teeth 12) is inclined toward the side where the comb teeth 12 protrude from the cutting edge towards the base of the comb teeth 1.

On the end faces of the comb teeth 12 in the comb blade 1, recessed grooves 13a are formed in the thickness direction of the comb blade 1 and in the direction opposite to the protruding direction of the comb teeth 12. Incidentally, one or more grooves 13a provided on a single comb tooth 12 are positioned to be biased towards the cutting edge portion of the cutting surface.

For example, in the example shown in Figure 3, three grooves 13a are concentrated on the cutting edge side half of the cut surface. These three grooves 13a have the same or approximately the same depth, and the spacing between adjacent grooves is also the same or approximately the same.

Figure 4 is an enlarged front view of the cutting edge side of a pair of blades. As shown in Figures 3 and 4, these thinning scissors are provided with five types of comb teeth 12, each with 0 to 4 grooves 13a. Here, a comb tooth 12 with 0 grooves 13a means a comb tooth 12 without any grooves 13a. When a comb tooth 12 has one groove 13a, this groove 13a is recessed in the cutting edge end of the end face of the comb tooth 12. When a comb tooth 12 has multiple grooves 13a, the multiple grooves 13a are recessed in a sequential, parallel manner from the cutting edge end of the end face of the comb tooth 12 toward the base of the blade.

Among the multiple comb teeth 12, at least one combination of comb teeth 12 with different numbers of grooves 13a formed on them is provided, or at least one combination of comb teeth 12 with grooves 13a and comb teeth 12 without grooves 13a is provided. Furthermore, among the multiple comb teeth 12, multiple combinations of comb teeth 12 with different numbers of grooves 13a formed on them are provided, as well as multiple combinations of comb teeth 12 with grooves 13a and comb teeth 12 without grooves 13a are provided.

In the illustrated example, the comb tooth 12 closest to the cutting edge has four grooves 13a, the second closest has three grooves 13a, the third closest has two grooves 13a, the fourth closest has one groove 13a, and the fifth closest has no grooves 13a.

In other words, the region where these five comb teeth 12 are arranged is a region in the comb blade 1 where the density of grooves 13a gradually decreases from the cutting edge towards the base of the blade.

On the other hand, as described above, the fifth tooth 12 closest to the cutting edge of the comb tooth 12 does not have a groove 13a formed thereon, the sixth tooth 12 closest to the cutting edge of the comb tooth 12 has two grooves 13a formed thereon, and the seventh tooth 12 closest to the cutting edge of the comb tooth 12 has three grooves 13a formed thereon.

In other words, the region where these five comb teeth 12 are arranged is a region in the comb blade 1 where the density of grooves 13a gradually increases from the cutting edge towards the base of the blade.

Incidentally, the thinning scissors in this example have 29 comb teeth 12, and the number of grooves 13a on each comb tooth 12 changes from the tip to the base of the comb blade 1 as follows: 4→3→2→1→0→2→3→4→3→2→1→0→2→3→4→3→2→1→0→2→3→4→3→2→1→0→2→3→4. In other words, the comb blade 1 has alternating decreasing and increasing groove regions from the tip to the base. Furthermore, the depth of the grooves 13a is set to 0.07 to 0.09 [mm].

With the thinning shears configured as described above, the density of the grooves 13a changes continuously and seamlessly throughout its entire length by the comb blades 1, resulting in natural variations in the thinning state. This allows for adjustment of hair volume without any unnatural feeling.

Next, with reference to Figure 5, another embodiment of the present invention will be described, showing the differences from the above-described embodiment.

Figure 5 is an enlarged front view of the cutting edge side of a pair of thinning scissors according to another embodiment. The number of comb teeth 12 on the comb blade 1 is 28, and the number of grooves 13a on each comb tooth 12 may change from the cutting edge to the base of the comb blade 1 as follows: 4→3→2→1→2→3→4→4→3→2→1→2→3→4→4→3→2→1→2→3→4→4→3→2→1→2→3→4. That is, this other example of thinning scissors does not have comb teeth 12 without grooves 13a.

1 Comb blade 2 Rod blade 8 Axis support 12 Comb teeth 13 Enlarged section 13a Groove

Claims (5)

Comb blades,
A rod blade and
The comb blade and the rod blade are connected to each other by a pivot support that allows them to rotate relative to one another.
The comb blade has a plurality of comb teeth that protrude along the tangential direction of its rotational trajectory,
At least some of the comb teeth formed on the comb blade have one or more grooves formed on their protruding end faces, in the direction opposite to the direction of protrusion and along the thickness direction of the comb blade.
Among the multiple comb teeth, at least one set of comb teeth is provided in which the number of grooves formed on each tooth differs from that of the comb teeth, or at least one set of comb teeth is provided in which a groove is formed and a comb tooth is not formed .
The comb blade is provided with a decreasing region in which the density of grooves gradually decreases from the tip of the blade toward the base of the blade, and an increasing region in which the density of grooves gradually increases . The thinning scissors according to claim 1, wherein multiple sets of comb teeth are provided, in which the number of grooves formed on each tooth differs from that of the comb teeth, and multiple sets of comb teeth are also provided, in which the comb teeth have grooves formed on them and the comb teeth do not have grooves formed on them. The thinning scissors according to claim 1, wherein the comb blade is provided with a plurality of decreasing regions where the density of the grooves gradually decreases from the tip of the blade towards the base of the blade, and increasing regions where the density of the grooves gradually increases. The thinning scissors according to claim 1, wherein the comb teeth are curved along the rotational trajectory of the comb blade. The protruding end of the comb teeth is made into an enlarged portion whose cross-sectional area is larger than that of the other parts.
One or more grooves are provided on the protruding end face of the enlarged portion , biased toward the cutting edge.
The thinning scissors according to claim 1.