EP0949989B1 - Heatable cutting instrument, specially scissors, knife, clippers or the like - Google Patents

Abstract

A heatable cutting device has a plastic base body having a recess on one side thereof. A cutting blade, made of metal or ceramic, is inserted into and fixedly connected to the recess. An electric heating element for heating the cutting blade is provided. The electrical heating element is fixedly and permanently connected to a side of the cutting blade facing the base body. The electrical heating element is attached to the cutting blade by printing, sintering or gluing. An electric connection for connecting the cutting device to an electric voltage supply device for operating the electrical heating element is provided. A temperature sensor is connected to an upper side of the cutting blade in the area of the cutting blade that is heated by the heating element.

Description

The invention relates to a heatable cutting instrument, in particular scissors, knives, Hair clipper or the like

Heated cutting instruments, in particular heated scissors for cutting hair have the advantage that the hot cutting blades while cutting the hair the ends of the hair are cauterized. This means that the tips of the hair melt easily. The ends of the hair are sealed to a certain extent, and it makes you feel Counteracted hair splitting.

A heatable cutting instrument in the form of heatable scissors is from WO 92/00688 known, which is regarded as a description of the closest prior art becomes. The basic idea is to use a blade holder that defines a basic body to arrange a separate cutting element made of metal with a front cutting edge. For this purpose, the blade holder has a step-shaped recess into which the cutting element is inserted and screwed to the blade holder. Between the Blade holder and the cutting element, a separate heating foil is arranged. This will electrically powered by an electrical power supply device. The heating resistor heats up the cutting element. - The disadvantage of this known heated scissors lies in the arrangement of the heating element in the form of a separate heating foil, which between the blade holder and the actual cutting element must be arranged. The disadvantage is that moisture can penetrate very easily, which leads to the destruction of the Heating foil can lead. The assembly of the heated scissors is also cumbersome.

Another heatable scissors is disclosed in DE-U-295 06 308. Here is the cutting blade covered on the outside by a plastic body. Between this plastic body and the actual cutting blade is also arranged a separate heating foil. The major disadvantage of this known heated scissors is that moisture in very easily penetrate the space between the cutting blade and the plastic cover can sooner or later lead to the destruction of the heating foil. Accordingly, this is heated scissors also associated with many failures.

Another problem with all known heated scissors is that Cable for electrically connecting the scissors to the electrical power supply break frequently. This means that the scissors are completely disassembled to repair the cable must be in order to be able to pull in a new cable. This is obviously cumbersome and expensive.

The invention has for its object to provide a heatable cutting instrument with improved durability.

The technical solution is characterized by the features of claim 1.

The advantage of the heated cutting instrument designed in this way is that the electrical Heating element due to its permanent, permanent and fixed arrangement on the Cutting blade is integrated in this and overall a compact unit cutting blade / heating element is formed. Due to the fixed attachment of the heating element to the cutting blade the heating element is encapsulated to a certain extent and so compared to known ones Heating foil arrangements less accessible to moisture and thus corrosion. The great advantage of the heatable cutting instrument according to the invention lies in its very high functional reliability with a long service life without failures. The power supply of the electrical heating resistor takes place via a corresponding electrical Control unit. So that the cutting blade has the desired temperature, is still a temperature sensor is provided in the heating area for an exact temperature measurement. Just like the heater, the temperature sensor can also be attached to the cutting blade his. Alternatively, it is also conceivable that this lies separately on the cutting blade. This temperature sensor is also connected to the control unit. Especially that Imprinting represents the preferred arrangement of the electrical heating element on the cutting blade In this case, no heating foil is used. Rather, the heating element applied to the cutting blade using thick-film technology. In particular, it will electric heating element printed by screen printing. This means that a current-carrying Paste printed, i.e. is applied and then baked. Such one The heating conductor can have a thickness of 4 micrometers. This is enough to get the cutting blade to bring to the desired temperature. The ceramic cutting blade stands out through a long service life in terms of their sharpness properties. Alternatively, you can metal can also be used. By using the cutting blade as a separate component on one Base body is arranged, this has the advantage that the heating element in a simple manner can be attached to the cutting blade. The cutting blade prepared in this way can then attached to the actual base body of the cutting instrument, for example glued on, riveted or screwed. Since the base body is made of plastic, it can can be produced by a simple injection molding process.

According to the development in claim 2, the heating element is designed as a thin line, which extends along the cutting edge at a parallel distance from it.

A further development of the cutting instrument according to the invention suggests Claim 3 before that the cutting blade is under electrical voltage. In this case the cutting blade is made of an electrically conductive material, namely metal. equally but it is also conceivable to have a ceramic cutting blade with a corresponding To provide metal layer, which has the necessary electrical properties. Because the cutting blade is under electrical voltage, it is simultaneously with hair trimming allows electrical irritation to the scalp. It is just still required to connect the body to the other pole of the power supply, so that a corresponding current flows along the hair.

The basic idea of the training according to claim 4 is the connection cable of the electrical power supply device not to lead directly to the heating element, but establish the connection using an electrical connector. The electrical The plug connection can be made using a plug / socket. This is the electrical connector firmly integrated in the cutting instrument. The advantage is that in the event of a break of the connecting cable, this can be replaced quickly and easily without, for example the entire scissors including the heating element are disassembled got to.

Preferably, according to claim 5, the electrical connector in the operating handle arranged. This is a technically simple way to connect the connecting cable to be able to connect the electrical connector. With heated scissors to arrange the electrical connector especially in the area of a finger eyelet his.

The development according to claim 6 has the advantage that the cables do not interfere. At a Scissors will be the cable guide in the grip area.

The advantage of scissors according to the development in claim 7 using a Roller bearing is that the scissors compared to conventional scissors considerably is smoother since the rolling bearing reduces the frictional resistance. The term "Rolling bearing" is to be understood as a generic term under which all bearings fall, which to reduce the frictional resistance between two moving parts. In particular Rolling bearings include ball bearings, plain bearings and needle bearings.

Fig. 1

eine Ansicht einer ersten Ausführungsform der Schere;

Fig. 2

einen Schnitt durch die Schneidklinge der Schere in Fig. 1;

Fig. 3

eine dazu etwas modifizierte, nicht erfindungsgemäße Ausführungsform der Darstellung in Fig. 2;

Fig. 4

eine Einzelansicht der Schneidklinge der Schere in Fig. 1;

Fig. 5

ein Detailausschnitt der Schere in Fig. 1 im Bereich der Grifföse;

Fig. 6

eine Ansicht einer zweiten Ausführungsform der Schere;

Fig. 7

einen Schnitt durch die Schere in Fig. 6 im Bereich der Schwenkeinrichtung in vergrößertem Maßstab;

Fig. 8

eine Explosionsdarstellung der Schwenkeinrichtung in Fig. 7.

Two exemplary embodiments of a heatable cutting instrument according to the invention in the form of heatable scissors are described below with reference to the drawings. In these shows:

Fig. 1

a view of a first embodiment of the scissors;

Fig. 2

a section through the cutting blade of the scissors in Fig. 1;

Fig. 3

a somewhat modified embodiment of the representation in FIG. 2, not according to the invention;

Fig. 4

a single view of the cutting blade of the scissors in Fig. 1;

Fig. 5

a detail of the scissors in Figure 1 in the area of the handle eyelet.

Fig. 6

a view of a second embodiment of the scissors;

Fig. 7

a section through the scissors in Figure 6 in the region of the pivoting device on an enlarged scale.

Fig. 8

7 shows an exploded view of the swivel device in FIG. 7.

The heated scissors in Fig. 1 consists of a base body 1 made of plastic. This Base body 1 has an actuating handle 2 with two finger eyelets 3.

In the front area, the base body 1 has a separate one in the blade area Cutting blade 4 made of ceramic. At the front end, the cutting blade 4 has the usual one Cutting edge 5. The separate cutting blade 4 made of ceramic is in a corresponding Recess 6 inserted in the base body 1 made of plastic and firmly connected to it, for example glued, screwed or riveted. On the body 1 facing Top of the cutting blade 4 has this along and at a parallel distance Cutting edge 5 on an electrical heating element 7, as can be seen in particular in FIGS. 2 and 4 to let. This heating element 7 is designed as a line and is on the Cutting blade 4 is printed, for example, by means of screen printing. 2 is the thickness of the Heating element 7 shown exaggerated. In reality, the thickness of the heating element is 7 only 4 microns. As a result, there is an integrated unit between the cutting blade 4 and the heating element 7 created, in which the heating element 7 firmly and permanently and permanently on the Top of the cutting blade 4 is arranged.

Furthermore, a - not shown - temperature sensor is provided, which equally can be attached to the top of the cutting blade 4.

A modified embodiment is shown in FIG. 3. Here is the basic body 1 made of metal and has a corresponding recess 6. This can be done, for example can be achieved that a conventional metal scissors is milled accordingly. Here, too, there is an identical cutting blade 4 in the recess 6 of the metallic base body 1 used. The only difference to the embodiment in Figs. 1 and 2 is in that an additional insulation between the cutting blade 4 and the base body 1 8 is arranged. This insulation 8 serves on the one hand as thermal insulation (so that the high temperature of the cutting blade 4 does not transfer to the base body 1) and continue as electrical insulation. This version is not protected by the claims.

For the electrical voltage supply of the heating element 7 (and of the temperature sensor) serve cables 9. These are connected to the heating element 7, as in particular Fig. 4th reveals. The cables are through the base body 1 back to the operating handle 2 out and end there in an electrical connector 10, which as electrical socket is formed. For electrical power supply (as well as for temperature sensing) can then an electrical connection cable based on the electrical Supply unit led to the scissors and with the electrical connector 10 be electrically connected.

5 that the actuating handle 2 is separate from the main body 1 formed and fastened by means of a screw 11. This allows different Operating handles 2 can be used according to the respective needs. It is further recognizable that between the actual base body 1 and the operating handle 2 a stopper 6 is arranged in the form of an O-ring. Also in this drawing recognizable how the cables 9 are passed through the operating handle 2 and on the electrical connector 10 open in the form of a socket.

Finally, it can be seen in Fig. 5 that the interior of the finger eyelet 3 of the operating handle 2 is equipped with an interchangeable ring 13.

Not shown is the possibility of cutting blade 4 (if it is made of metal) to energize, thereby causing a current flow during hair cutting to produce in the hair, provided a to the body of the person concerned appropriate counter electrode is applied. Through this flow of electricity, the scalp irritated and thereby stimulated.

The scissors of the second embodiment in FIGS. 6 to 8 (in the rest of which the heating device is omitted for the sake of simplicity and clarity) points in conventionally two cutting blades 21, 21 '. The cutting blades on the back each have an actuating handle 22, 22 'with finger eyelets 23, 23'. In the intermediate area there is a between the cutting blades 21, 21 'and the actuating handles 22, 22' Swivel device 24, by means of which the two cutting blades 21, 21 'with respect to an axis of rotation A are pivotable against each other. The swivel device 24 is by a Opening 25 formed in the two cutting blades 21, 21 'through which one Screw 26 is inserted. This screw 26 has a head 27, which on the underside is bevelled upwards. On the opposite On the side of the head 27 of the screw 26 there is a nut 28. This also points a head 29 and is positively held in the lower cutting blade 21 '.

A roller bearing 30 is additionally assigned to the swivel device 24. This is in a recess 31 is inserted in the outside of the cutting blade 21 in a press fit. The Rolling bearing 30 has an outer ring 33 and an inner ring 34. Between the Outer ring 33 and inner ring 34 are balls 35. The rolling bearing has in the middle 30 an opening 36 for the screw 26.

The outer ring 21 is fixed by the interference fit in the recess 21 of the cutting blade 21 arranged. With regard to this fixedly arranged outer ring 33, the inner ring 34 is inside the recess 31 rotates freely. The head 27 of the screw 26 rests in the rotationally fixed Friction on the top of the inner ring 34. Because the outer area of the bottom of the head 27 of the screw 26 is chamfered upwards, it does not touch the top of the outer ring 33 of the rolling bearing 30.

For example, the lower cutting blade 21 'with respect to the fixed upper Cutting blade 21 rotated about the axis of rotation A, the rotational movement is via the nut 28, transfer the screw 26 and its head 27 to the inner ring 34 of the rolling bearing 30. As a result, the cutting blade 21 'is very easy to move with respect to the cutting blade 21 Tightening the screw 26 can the contact pressure between the two cutting blades 21, 21 'can be changed.

LIST OF REFERENCE NUMBERS

1

body

2

operating handle

3

finger loop

4

cutting blade

5

cutting edge

6

recess

7

heating element

8th

insulation

9

electric wire

10

electrical connector

11

screw

12

stopper

13

ring

21, 21 '

cutting blade

22, 22 '

operating handle

23, 23 '

finger loop

24

Pivot means

25

perforation

26

screw

27

head

28

mother

29

head

30

roller bearing

31

recess

32

outside

33

outer ring

34

inner ring

35

Bullet

36

perforation

A

axis of rotation

Claims (7)

1. Heatable cutting instrument, in particular scissors, cutters, hair trimmers or similar,
   with a base body (1) of plastic,
   with a separate cutting blade (4) of metal or ceramic set in a step-like recess (6) on one side of the base body (1) and firmly connected to this,
   with an electric heating element (1) for heating the cutting blade (4),
   where the electric heating element (7) is permanently and firmly attached to the cutting blade (4) on the side facing the base body (1) between the base body (1) and the cutting blade (4) by push fit, sintering or gluing,
   with an electrical connection to operate the electric heating element (7) by means of an electric power supply device
   and with a temperature sensor arranged on the top of the cutting blade (4) in the heating area.
2. Cutting instrument according to the previous claim,
   characterised in that
   the electric heating element (7) is formed as a line along the cutting edge (5) of the cutting blade.
3. Cutting instrument according to any of the previous claims,
   characterised in that
   the cutting blade (4) is under electric voltage.
4. Cutting instrument according to any of the previous claims,
   characterised in that
   arranged on the cutting instrument is an electric plug connection (10) for connecting a cable of the electric power supply device for the electric power supply to the heating element (7).
5. Cutting instrument according to claim 4,
   characterised in that
   the electric plug connection (10) is arranged on the operating handle (2).
6. Cutting instrument according to claim 4 or 5,
   characterised in that
   the cables (9) from the electric plug connection (10) to the electric heating element (7) run within the body of the cutting instrument.
7. Cutting instrument according to any of the previous claims,
   characterised in that
   the cutting instrument is scissors with two cutting blades (21, 21') swivellable towards each other about an axis of rotation (A) by means of a swivel device (24) with a roller bearing (30).

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