WO1996035557A1

WO1996035557A1 - Scissors, especially hairdresser's scissors

Info

Publication number: WO1996035557A1
Application number: PCT/DE1996/000731
Authority: WO
Inventors: Hardi Schmidt
Original assignee: 'jaguar' Stahlwarenfabrik Gmbh & Co. Kg
Priority date: 1995-05-13
Filing date: 1996-04-26
Publication date: 1996-11-14
Also published as: DE19517654C1; KR19990014707A; EP0828589A1; JPH11504832A

Abstract

In a pair of hairdresser's scissors with two blades (1, 2) articulatedly joined together at a pivot (3) and having cutting edges, at least one (2) of which is distinctly curved, in which the included angle between the blade interaction starting point (1, 2) from the blade interaction starting point (8) to the tip (9) is substantially constant about 21° within a predetermined tolerance range, in order to avoid the hair's being pushed away during cutting, the curved blade (2) has a short, oblique step (10) continuing the cut (7) between the blade interaction starting point (8) and the pivot (3) which merges in a short arc into the cutting edge (7) and the angle between the step (10) and the opposite blade (1) is greater than the largest angle (x) included between the blades (1, 2).

Description

Scissors, in particular hairdressing scissors

The invention relates to a pair of hairdressing scissors with two scissor blades which are articulated to one another and provided with cutting edges, of which at least one scissor blade is clearly curved, and two scissor blades which continue the scissor blades behind the trade and have grip eyes at the ends, the opening angle of which Scissor blades from the blade insert to the tip is essentially constant within a predetermined tolerance range of 21 °.

Such scissors have the highest quality requirements, which relate, for example, to the fact that they have an ergonomically favorable design and must ensure easy handling with constant closing pressure in order to counteract rapid fatigue of the muscles. In addition, a flawless and in particular step-free cutting of the hair must be possible. For the precise cut, the shape and the grinding of the cutting edges of the scissor blades and the fine deduction of the cutting edges are decisive.

Scissors that largely meet these requirements have become known from various publications. For example, one such from DE 43 04 578 AI Hairdressing scissors. With scissors of this type, the blades of both scissor blades are designed to be almost straight or slightly curved in order to achieve a closing movement that is as uniform as possible over a larger area when the scissors are closed and in particular to achieve a particularly slim shape of the scissors. Of course, it is also possible to provide only one scissor blade with a slightly curved cutting edge and the other scissor blade with a straight cutting edge.

A disadvantage of these scissors has been that good cutting results depend not only on the good sanding and fine removal of the cutting edges, but also considerably on the skill of the hairdresser. However, it has been shown that pushing of the hair can occur during the cutting process, i.e. the hairs are not grasped and cut by the cutting edges, but are more or less pushed away and only cut later during the further closing movement of the scissor blades. This pushing inevitably leads to an uneven and in particular stepped cut, so that it is then necessary to rework several times. However, the occurrence of this effect must largely be ruled out for scissors that are intended to meet the highest quality requirements.

It is not possible to calculate in advance the opening angle at which the hair is pushed, since in addition to the geometric conditions, the condition of the cutting surfaces and the strength of the hair itself must also be taken into account here. In theory, with a very small opening angle, it is hardly to be expected that the hair will be pushed, but the continuous cutting durability is adversely affected. At large opening angles, the shear force component of the shear force is relatively large, so that the hair can easily be pushed. The condition of the cutting edge also influences the pushing of the hair to a considerable extent, the influence being particularly great in the scissors described at the beginning.

Another disadvantage of the known scissors can be seen in the fact that hair can become jammed in the area between the blade insert and the trade, which can at least be perceived as annoying.

From the German Offenlegungsschrift P 28 18 913 a pair of scissors is known in which the cutting angle formed between the cutting edges is essentially constant and in which the object to be cut is not to be pushed between the blades. The curves formed by the cutting edges are mirror images etal et. This mirror-image configuration is not appropriate for hairdressing scissors.

A cutting device is also known from US Pat. No. 4,422,24C, in which the cutting angle is kept approximately constant and which moves approximately between 13 ° to 20 °. However, this cutting device is used for cutting metal sheets and wires and is not suitable for cutting hair. In addition, the cutting edges of this cutting device are also mirror images.

Finally, from US-A-26 80 294 a pair of scissors is known whose scissor blades have an asymmetrical outline. The pushing or slipping of the materials to be cut is to be achieved here in that the blade has a convex curvature and the other has a concave curvature, so that the cutting edge presses into the cut with the convex curvature, so that an increase in the cutting angle force is achieved. The invention is therefore based on the object of creating scissors, in particular hairdressing scissors, which avoids the disadvantages of the prior art.

The object on which the invention is based is achieved in a pair of scissors of the type mentioned at the outset in that the arcuate scissor blade between the blade insert and the trade is provided with a short, oblique gradation which continues the cutting edge, which merges into the cutting edge in a short arc, and in that Angle between the gradation and the opposite shear blade is larger than the largest opening angle between the shear blades.

By pushing the hair in the entire working area of the scissors, i.e. from insert to tip, prevented or reduced to a negligible amount. At the same time, the continuous cutting speed is sufficiently guaranteed. The gradation ensures that the undesirable effect of pushing the hair is deliberately created in the area of the trade at the cutting attachment in order to exclude with certainty any accidental jamming of hair in the area of the trade.

If the scissor blade is designed so that its curvature increases towards the tip, the tolerance range of the opening angle can be kept particularly small.

The opening angle should be at least 16 ° and preferably between 24 ° at the blade insert and 19 ° at the tip 1.

In an advantageous development of the invention, the angle between the gradation and the opposite scissor blade is greater than 24 °. A special design of the scissors is achieved if the outline of both scissor blades has the same shape, so that a particularly pleasing shape is achieved when the scissors are closed. It also simplifies manufacture.

The invention will be explained in more detail below using an exemplary embodiment. The accompanying drawings show:

Fig. 1 is a schematic representation of the scissors with the inventive design of the scissor blades;

2 to 4 representations of the scissors at different opening angles within the tolerance range.

The basic structure of the scissors is shown in FIG. 1. As usual, this consists of two scissor blades 1, 2 which are connected to one another in a trade 3 and are continued on the other side of the trade 3 in scissor blades 4, 5 which end in eyes 6. The cutting edge 7 of the scissor blade 2 is clearly arcuate, so that the opening angle α between the blade insert 8 and the tip 9 is between 19 ° and 24 °.

If the cutting edge 7 of the scissor blade 2 is designed so that its curvature increases towards the tip 9, the tolerance range of the opening angle x can be kept very small. If the scissors are to be made particularly slim, both cutting edges 7 can also have the same curvature. The curvature of the cutting edges 7 should be chosen so that the opening angle a is at least 16 ° and is, for example, between 24 ° at the blade insert 8 and 19 ° at the tip 9. The relationship between the pushing force Fs and the shear force F (FIG. 1) can be described theoretically by calculating the pushing force according to the formula Fs = (sin ax F) / 2, but in practice the most favorable opening angle a of the scissor blades 1, 2 can not be determined, because in addition to the geometric conditions, the condition of the cutting edges 7 and the strength of the hair itself must also be taken into account. In general, with a very small opening angle x, the hair can hardly be pushed. At very small opening angles x, however, the continuous cutting dhalti gkei t is adversely affected, ie the cutting edges 7 wear out relatively quickly. At large opening angles x, however, a relatively large shear force component of the shear force is achieved, so that pushing of the hair can easily occur.

The design of the cutting edges 7 means that the hair is pushed in the entire working area of the scissors, i.e. from blade insert 8 to tip 9 prevented or reduced to a negligible level. At the same time, the continuous cutting stability is sufficiently guaranteed.

The clearly curved design of at least one cutting edge 7 gives the scissor blades 1, 2 an asymmetrical outline so that they stand out clearly from the scissor blades 1, 2 known scissors.

A special design of the scissors is achieved if the outline of both scissor blades 1, 2 is chosen to have the same shape - so that a particularly pleasing shape is achieved when the scissors are closed.

In order to prevent hair from getting caught in the area between the blade insert 8 and the handle 3, the cutting edge 7 of the curved scissor blade 2 is on the blade insert 8 provided with a short oblique or arcuate gradation 10. This gradation 10 merges into the cutting edge 7 in a short arc. As a result, a significantly larger opening angle x is achieved in this area compared to the working area of the scissor blades 1, 2, as can best be seen from FIG. 4. The angle between the gradation 10 and the opposite scissor blade 1 is larger than the largest opening angle x between the scissor blades 1, 2. As a result, the pushing force in this area is sufficiently large that the hair is pushed from this area into the working area of the scissor blades 1, 2. In this way, the undesirable effect of pushing the hair in this area is consciously exploited in order to prevent jamming of hair in the area of the trade 3 between the scissor blades 1, 2 on the blade insert 8.

Reference symbol list

Scissor blade scissor blade commercial scissor blade scissor blade eye cutting blade insert tip gradation

Claims

claims

1. Hairdressing scissors with two scissors blades articulated in a trade, provided with cutting edges, of which at least one scissor blade is clearly curved and two scissor blades that continue the scissor blades behind the trade, with grip eyes attached to the ends, whereby the opening angle of the scissor blades from the blade insert to the tip is essentially constant within a predetermined tolerance range of 21 °, since ¬ is characterized by the fact that the curved scissor blade (2) between the blade insert (8) and the trade (3) is included a short, the cutting edge (7) continuing oblique step (10) is provided, which merges in a short arc into the cutting edge (7) and that the angle between the step (10) and the opposite scissor blade (1) is greater than the largest opening angle (x) between the scissor blades (1,2).

2. hairdressing scissors according to claim 1, so that the curvature of the scissors blade (1; 2) increases towards the tip (9).

3. hairdressing scissors according to claim 1 and 2, dadurchge¬ indicates that the opening angle (x) is between 24 ° on the blade insert (8) and 19 ° at the tip (9).

4. hairdressing scissors according to claims 1-3, d a d u r c h g e k e n n z e i c h n e t that the angle between the gradation (10) and the opposite scissor blade (1) is greater than 24 °.

5. hairdressing scissors according to claims 1-4, d a d u r c h g e k e n n z e i c h n e t that the outline of the scissors blades (1,2) is substantially the same shape.