EP0930959B1 - Scissors - Google Patents

Abstract

The scissors for cutting filamentary material, especially hair, include two shanks (4) pivotally connected to each other at a pivot joint (2); respective blades (7) for cutting the filamentary material extending from the shanks (4) and an electrically powered vibrator (5) for vibrating one of the shanks in a longitudinal direction at an ultrasonic frequency and with a displacement of about 100 to 200 mum. The pivot joint (2) includes a nail (14) extending from one shank, an eccentric washer (15) embedded in the other shank which engages around the nail and a miniature motor (17) for rotating the washer (15) and the shank in which it is embedded. In other embodiments the electrically powered vibrator (5) include a piezoelectric transducer (8) arranged to connect a shank to one of the blades or an exciter coil (19) wrapped around a strut region made of a magnetostrictive material in one shank.

Description

The invention relates to a pair of scissors with one another via a joint connected Beck's, especially hairdressing scissors.

US-A-3 666 975 publishes a pair of scissors according to the preamble of claim 1. JP-A-2031788 publishes a pair of scissors according to the preamble of claim 2.

Known scissors work on the principle of two cutting edges, which move around a common, fixed pivot point. The cutting edges slide on each other in such a way that they touch at one point (cutting point).
When the scissors close, the cutting point moves from the direction of the common pivot point of the scissors towards the tip of the scissors.
This also changes the opening angle of the scissors, i.e. the angle of the cutting edges running towards each other.
Thread-like clippings, e.g. B. hair, slides depending on the opening angle, sharpness, etc. more or less long before the actual cutting point until it is cut, held and then separated. Since the clippings do not perform a defined rolling movement around their longitudinal axis with this method of cutting, only a partial cross section of the clippings is inevitably cut, the rest are virtually squeezed to torn off.
Inadequate cut hair is ultimately an approach for consequential damage and can u. U. lead to split ends.

The invention is based on the object, thread-like clippings, especially hair, even over its circumference and cross-section without To cut squeeze and tear zones.

This object is achieved by the subject matter of claims 1 and 2. After that, at least one Beck of the scissors is electric by means of a operated vibration device in a vibration parallel to Movable in the longitudinal direction of this pool.

The invention has the advantage that thread-like clippings, in particular Hair, evenly over its circumference and cross section without squeezing and Tear zones can be cut. With the scissors according to the invention rolls and glides the hair between the blades when it is cut. It is cut reliably and evenly. When closing the Scissors axially guide the additional at least one cutting edge oscillating motion component to this improved cutting property.

Further advantageous embodiments of the invention are in the claims 3 to 7 described.

Good cutting results are achieved if according to claim 1 Vibration device contains a piezo transducer, which between the Blade and a handle-side cymbal lies, and the one connection between the sheet and the end of the pelvis. The oscillating movement is determined by the frequency and the amplitude with which the Piezo sensor swings.

The oscillating movement should be carried out at such a high frequency. that within normal use of scissors in the cutting process, the hair rolls over its circumference at least once on the cutting edges.
The vibration amplitude depends on the hair size. Approx. 100 to 200 µm can be set for the amplitude (claim 6). If both cutting edges vibrate simultaneously and are out of phase with each other, half the amplitude is sufficient.
A system with adjustable amplitude and frequency for different clippings is possible.

The piezo sensor can be operated with an ultrasonic frequency. It is integrated in at least one cutting edge. Analogous to an ultrasonic cleaning or welding sonotrode, the longitudinal shaft is transferred to the cutting edge. The ultimately mechanical vibration generator can be arranged on the cutting side or straw side of the scissors. A corresponding mechanical play in the bearing point should be noted on the straw side. The latter also applies to other vibration devices on the stalk.
The system is controlled electrically by an ultrasonic generator, which is coupled to the electromechanical transducer via electrical connecting lines.

Good cutting results are also achieved when on the nail of the joint as an oscillating device an eccentric disk enclosing the nail is provided, the eccentric in a round recess of the Becks inserted and rotatably connected to the nail, and one Smallest motor provided for rotating the eccentric disc around the nail is (claim 2). A standard connection nail is replaced by a Electromechanically driven eccentric unit replaced. The axial component the eccentric movement leads to the desired cutting movement. On The smallest motor is sufficient to drive the eccentric unit and has that Advantage that it does not affect the handling of the scissors.

The vibration device can also be designed such that the Beck at least in regions made of a magnetostrictive material exists, which is wrapped by a rigid, stationary excitation coil (Claim 4). The scissor blades are on a basic body applied from magnetostrictive material. By applying an electromagnetic Field on the magnetostrictive material becomes a change in length of the material and ultimately an oscillation of the cutting edges to each other causes. The excitation coils can be found in the stalk area of the scissors be arranged. Via an electrical connection line Excitation coil connected to a generator.

Nickel or a nickel alloy is suitable as material (claim 6). On the one hand, nickel has the required magnetostrictive properties, on the other hand, nickel steel is very well suited for the manufacture of scissors. To the Avoiding a contact allergy, the material can have a plastic coating have (claim 5).

Figur 1

in einer Seitenansicht eine Schere, deren Becks über einen Nagel gelenkig miteinander verbunden sind, und deren griffseitige Beckenden jeweils ein Auge aufweisen, wobei als Schwingungsvorrichtung ein Piezoweggeber zwischen einem Blatt und dem Beckende vorgesehen ist;

Figur 2

in einer Seitenansicht eine Schere analog Figur 1, jedoch mit einer Schwingungsvorrichtung, die eine den Nagel umschließende Exzenterscheibe und einen Kleinstmotor zum Drehen der Exzenterscheibe aufweist, sowie

Figur 3

in einer Seitenansicht eine Schere analog Figur 1, jedoch mit einer Schwingungsvorrichtung, die ein magnetostriktives Material an einem Halm und eine das Material umgebende, starre, ortsfeste Erregerspule aufweist.

The invention is described in more detail below with reference to figures which illustrate exemplary embodiments. It shows:

Figure 1

in a side view a pair of scissors, the becks of which are articulated to one another via a nail, and of which the end of the pelvis on the handle side each has an eye, a piezo sensor being provided between a blade and the end of the pelvis as a vibration device;

Figure 2

in a side view of a pair of scissors analogous to FIG. 1, but with an oscillation device which has an eccentric disk surrounding the nail and a small motor for rotating the eccentric disk, and

Figure 3

1 is a side view of a pair of scissors analogous to FIG. 1, but with a vibration device which has a magnetostrictive material on a stalk and a rigid, stationary excitation coil surrounding the material.

In the case of scissors 1 with two connected to one another via a joint 2 Beck 3, 4 is a Beck 4 by means of an electrically operated vibration device 5 into an oscillation parallel to the longitudinal direction 6 of the blade 7 this Beck 4 displaceable (Figure 1). The vibration device 5 contains a piezo sensor 8, which lies between the blade 7 and the joint 2. The Piezegeggeber 8 is a connection 9, the blade 7 and the handle side Pool end 10 of the pool 4 connects together. The scissors 1 is as Hairdressing scissors 11 designed with eyes 12. An electrical line 13 supplies the piezo sensor 8 with an ultrasound frequency. During one Cutting process is the vibration of the blade 7, its amplitude 150 µm is used to cut hair better.

In the scissors 1 according to FIG. 2, the vibration device 5 is a Nail 14 of the joint 2 surrounding eccentric 15 provided inserted into a round recess 16 of the basin 4 and rotatable with the Nail 14 is connected. The eccentric disc 15 rotates around the nail 14. This rotational movement is achieved by means of a miniature motor 17. The entire Beck 4 carries out the vibration.

In the exemplary embodiment in FIG. 3, a magnetostrictive material 18 is provided as the vibration device 5, which is wrapped by a rigid, stationary excitation coil 19. The vibration device 5 is provided on the stem 20 of the basin 4. A magnetostrictive material 18 has been used only within the excitation coil 19. Otherwise, the scissors 1 are made of conventional scissor steel 22. The material 18 is a nickel alloy 23.
The basin 4 has a play 24 in the longitudinal direction 6 of the basin 4 on the nail 14. The game 24 has an extension of 150 μm in the longitudinal direction 6 corresponding to the amplitude of the vibration of the blade 7.

Reference list

1

scissors

2nd

joint

3, 4

Beck

5

Vibrating device

6

Longitudinal direction

7

sheet

8th

Piezo sensor

9

connection

10th

Pelvic

11

Hairdressing scissors

12th

eye

13

management

14

nail

15

Eccentric disc

16

Recess

17th

Micro motor

18th

magnetostrictive material

19th

Excitation coil

20th

Stalk

21

Culm area

22

Scissors steel

23

Nickel alloy

24th

game

Claims (7)

1. A pair of scissors having two arms connected to each other by way of a joint, wherein at least one arm (4) can be made to oscillate parallel to the longitudinal direction (6) of the blade (7) of the said arm (4) by means of an electrically driven oscillation device (5), the oscillation device (5) contains a piezo displacement pick-up (8) or a magnetostrictive material (18) with a rigid, stationary excitation coil (19) wound therearound, and the oscillation device (5) is situated between the blade (7) and the handle end (10) of the arm, characterized in that the oscillation device (5) is a connexion (9) integrated into the arm (4) between the blade (7) and the end (10) of the arm.
2. A pair of scissors having two arms connected to each other by way of a joint, wherein at least one arm (4) can be made to oscillate parallel to the longitudinal direction (6) of the blade (7) of the said arm (4) by means of an electrically driven oscillation device (5), characterized in that an eccentric disc (15) surrounding the pin (14) of the joint (2) is provided as the oscillation device (5), the eccentric disc (15) is inserted in a round recess (16) in the arm (4) and is connected to the pin (14) in a rotatable manner, and a miniature motor (17) is provided for rotating the eccentric disc (15) about the pin (14).
3. A pair of scissors according to Claim 2, characterized in that the oscillation device (5) is provided on the shank (20) of the arm (4), and there is play (23) between the arm (4) and the pin (14) in the longitudinal direction (6) of the arm (4).
4. A pair of scissors according to Claim 1, characterized in that nickel or a nickel alloy (22) is provided as the material (18) for the piezo displacement pick-up (8).
5. A pair of scissors according to Claim 4, characterized in that the material has a coating of plastics material.
6. A pair of scissors according to at least one of Claims 1 to 5, characterized in that 100 to 200 µm are provided as the amplitude of the oscillation device (5).
7. A pair of scissors according to at least one of Claims 1 to 6, characterized in that a respective oscillation device is provided on each of the two arms.

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