EP2906075B1 - Heating plate for a hair-styling iron - Google Patents

Description

The present invention relates to a hotplate for a hair straightener, in particular for a straightener. The invention also relates to a hair straightener with at least one such heating plate.

Heatable hair styling devices, in particular hair straighteners are well known and adapted to bring under the action of heat and optionally additionally by mechanical pressure / train the hair in a desired shape or to give them a desired appearance. Especially with hair straighteners, by applying heat and simultaneously exerting a mechanical force, the hair to be treated is smoothed. Such hair straighteners in this case have at least one usually electrically heatable heating plate which is brought into contact with the hair to be smoothed via a substantially flat and flat section. In addition, they have an opposite second, optionally heatable plate between which and the heating plate to be smoothed hair introduced and pulled through under pressure to be smoothed can.

The US 2010/101599 A1 discloses a heating plate for a straightener, comprising a base plate in thermal contact with a heating plate, the base plate having at least one recess on the second surface. The KR 100 858 147 B1 discloses a straightener having a base plate having a surface in contact with two heating elements.

In order to achieve particularly good smoothing results, it has been the aim to ensure the most uniform possible temperature distribution over the entire heating plate. This has been tried for example by means of ceramic painted aluminum plates, since aluminum has a much better thermal conductivity than, for example, glass or ceramic. Recent studies have shown, however, that heating plates with different temperature zones bring about a further improved smoothing result.

The present invention therefore deals with the problem of specifying a hotplate for a hair straightener, which is structurally simple on the one hand and on the other hand, at least two different temperature zones, in order to achieve an improved smoothing result can.

This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea to provide on one side of a base plate of a hotplate for a hair straightener on one side at least two recesses, which constitute a heat flow obstacle and which thereby subdivides a first surface facing the hair to be smoothed into at least two different temperature zones. The heating plate according to the invention in this case has a one-piece base plate, which has a trained for contact with hair to be formed first surface and a second surface opposite thereto. At least one electric heating element, for example a PTC element, is placed in thermal contact with the second surface, wherein the previously described recesses are introduced in the second surface, which constitute the heat flow obstacle described above and thereby the first surface into at least two different ones Divide temperature zones.

Due to the at least two different temperature zones on a single hotplate, the smoothing result can be significantly improved without, for example, having to provide two separate hotplates with correspondingly complex wiring and thus connected with comparatively difficult cleaning option. Thus, in the at least two different temperature zones, a different degree of heating power can be provided, wherein by the geometric design of the recesses, for example, in terms of their depth and / or width heat transfer, which overcome these recesses, can be adjusted. The deeper or wider these recesses are, the larger the heat flow obstacle produced thereby. The base plate itself can be formed, for example, from glass, ceramic, glass ceramic, temperature-resistant plastic, silicone or aluminum as a base material, whereby the introduction or provision of the recesses according to the invention is relatively easy. In the case of glass, in particular glasses are preferred which are suitable for use as a heating plate, such as quartz glass or borosilicate glass.

According to the invention, the at least two recesses are formed as a groove with an angular or round cross-section and, moreover, two such grooves are provided which run through the second surface in the longitudinal direction, that is orthogonal to the direction of passage of the hair to be formed. The length of the recesses is preferably the same length as the heating plate, that is, the recess passes through the heating plate Completely. Of course, not completely continuous recesses are conceivable, in particular in the manner of broken lines, similar to a median strip of a road, which can also influence the heat transfer rate between the two separated by the recess temperature zones can be taken. In the case described above, the at least one heating element is arranged according to the invention between the two grooves, so that there is given a temperature zone with a higher temperature. The two adjacent temperature zones have due to the heat flow obstacle generated by the respective recess / groove a lower temperature during operation of the hair straightener, so that when pulling the hair to be formed between two such heating plates they experience a much stronger heating in the middle temperature zone than in the two edge temperature zones. By gradual heating and cooling again during the smoothing process, a particularly effective smoothing of the hair can be achieved.

In a further advantageous embodiment of the solution according to the invention, at least one further heating element is provided. Of course, it is conceivable that the heating plate according to the invention not only has to be heated by a single heating element, but for example in adjacent and separated by the recess / groove temperature zones another heating element can be provided, the optional, that is in particular as needed to or . can be switched off. In this case, it is conceivable, in particular, that in the case of rapid smoothing of the hair, the heating power applied by only a single heating element is insufficient, so that in this case the at least one further heating element additionally contributes heating energy and thus also permits a fast and nevertheless effective smoothing of the hair.

In another embodiment, which is not part of the present invention, the heating element is at least partially disposed in the recess. If the recess has, for example, a rounded cross-section, then it is conceivable that the at least one heating element with a cross-section configured to be complementary thereto is arranged inside this recess and thereby likewise permits different temperature zones on the first surface of the heating plate facing the hair to be formed. In theory, heating elements are also conceivable which have a discontinuous thickness, so that their heating power introduced into the base plate is dependent on the respective thickness and thus likewise a subdivided into different temperature zones heating the base plate is made possible.

A control of the individual temperature zones can take place via corresponding temperature sensors, which are connected to a control device. Of course, it is also clear that the at least one recess does not have to have a linear shape, but for example can also be designed to meandering or otherwise running. The heating elements or the at least one heating element can be applied for example in the manner of a coating on the second surface of the base plate of the heating plate.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or in isolation without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Fig. 1

einen erfindungsgemäßen Haarglätter zumindest einer erfindungsgemäßen Heizplatte,

Fig. 2

eine Schnittdarstellung durch eine erste mögliche Ausführungsform der erfindungsgemäßen Heizplatte,

Fig. 3

eine Darstellung wie in Fig. 1, jedoch bei teilweise in der Ausnehmung angeordnetem Heizelement, welche nicht Teil der vorliegenden Erfindung darstellt,

Fig. 4

eine Darstellung wie in Fig. 2, jedoch mit zwei weiteren Heizelementen,

Fig. 5

eine Ansicht auf eine zweite Oberfläche der erfindungsgemäßen Heizplatte mit entsprechend angeordneten Ausnehmungen.

Show, in each case schematically,

Fig. 1

a hair straightener according to the invention at least one heating plate according to the invention,

Fig. 2

a sectional view through a first possible embodiment of the heating plate according to the invention,

Fig. 3

a representation like in Fig. 1 but with a heating element partially disposed in the recess, which does not form part of the present invention,

Fig. 4

a representation like in Fig. 2 but with two more heating elements,

Fig. 5

a view of a second surface of the heating plate according to the invention with correspondingly arranged recesses.

According to the Fig. 1 , An inventive hair straightener 1 has a forceps-like structure with a first arm 2 and a second arm 3, which are connected to each other via a hinge 4. The first arm 2 and the second arm 3 are connected to each other via the hinge 4 such that a free end of the first arm 2 and a free end of the second arm 3 are movable towards and away from each other, as shown in FIG Fig. 1 is shown schematically by an arrow. On the first arm 2 as on the second arm 3 each have a heating plate 5 is provided, which will be described in more detail below. Via an electrical connection line 6, the hair straightener 1 can be connected to an electrical network. The hairs to be smoothed can be brought between the two heating plates 5, in which case the two heating plates 5 are moved toward each other to enclose the hair between them and the hairs are smoothed by the action of heat and optionally exerting a slight mechanical pressure. It is of course clear that the hair straightener 1 may generally have only a single heating plate 5, so that on the opposite arm 2, 3 only a plate, which is not heated, however, would be arranged.

The heating plate 5 according to the invention has a base plate 7 which has a first surface 8 designed to make contact with the hair to be formed and a second surface 9 lying opposite this. With the second surface 9 in thermal contact is an electric heating element 10, as shown in the Fig. 2 to 5 is shown. According to the invention, the base plate 7 now has on its second surface 9 at least two, preferably a plurality of recesses 11, which constitute a heat flow obstacle and thereby the first surface 8 in at least two different temperature zones 12, 13 (see. Fig. 2 ). Looking at the Fig. 2 Thus, it can be seen that two recesses 11 are provided in the manner of grooves, which run through the base plate 7 in the longitudinal direction and between which the heating element 10 is arranged. The so-grooved base plate 7 thus has on her first surface 8, a temperature zone 12, which experiences a higher heating power, and two adjacent thereto second temperature zones 13, which experience a lower heating due to the heat flow obstacle generated by the recess 11.

The at least two recesses 11 are in this case as a groove with angular (see. Fig. 2, 4 ) or round cross section (cf. Fig. 3 ) educated. The recesses 11 are usually orthogonal to the direction of passage D of the hair to be formed.

Considering the embodiment of the heating plate 5 according to the Fig. 3 Thus, it can be seen that the recess 11 has a rounded cross-section there and also the heating element 10 is disposed within the recess 11, which does not form part of the present invention. In addition, the heating element 10 has a discontinuous thickness, which in turn allows different temperature zones to be realized on the first surface 8. Of course, the different thickness of the heating element 10 can also be used to obtain the most uniform temperature distribution at the first surface 8. In the heating plate 5 according to the Fig. 4 next to the heating element 10, two further heating elements 14 and 15 are arranged, which can cause an individual, in particular supporting heating of the respectively associated temperature zones 13. Of course, while the other heating elements 14, 15 purely purely optional, that is switched on when needed.

Between the heating element 10 and the respective further heating element 14, 15 in this case runs the heat flow obstacle performing recess 11, which preferably completely passes through the base plate 7 of the heating plate 5 (see. Fig. 5 ). Alternatively, it may be provided for an interrupted embodiment of the recess 11, as in the lower half of Fig. 5 is shown.

The base plate 7 of the heating plate 5 may for example be made of ceramic, glass, glass ceramic, temperature-resistant plastic, silicone or aluminum and in particular coated on the two surfaces 8, 9 as needed. For example, it is conceivable that the application of a lubricious coating is provided on the first surface 8.

With the heating plate 5 according to the invention and a hair straightener 1 equipped therewith, a significantly improved smoothing result can be achieved, as with uniformly heated heating plates, in particular due to the different temperature zones 12, 13. The number and geometric shape of the individual recesses 11 Fig. 2,4,5 It should be understood purely by way of example, so that a higher number or, for example, a meandering course of the recesses 11 should be included in the invention.

Although a hair straightener 1 has always been described in the figures, it may of course alternatively also be a general heatable hair styling device, in particular a curling iron or a so-called multi styling device.

LIST OF REFERENCE NUMBERS

1

hair straightener

2

first arm

3

second arm

4

joint

5

heating plate

6

connecting cable

7

baseplate

8th

first surface

9

second surface

10

heating element

11

recess

12

first temperature zone

13

second temperature zone

14

another heating element

15

another heating element

Claims (5)

1. Heating plate (5) for a hair-styling iron (1), in particular for a straightener, having a base plate (7) which has a first surface (8) embodied for contact with hair to be shaped and a second surface (9) opposed thereto, having an electrical heating element (10) in thermal contact with the second surface (9), wherein the base plate (7) at the second surface (9) has at least one recess (11) embodied as a groove with an angular or round cross-section which represents a heat flow obstacle and thereby divides the first surface (8) into at least two different temperature zones (12, 13), characterised in that two grooves are provided, which pass through the second surface (9) in the longitudinal direction, i.e. orthogonally to the direction of passage (D) of the hair to be shaped, and in that the heating element (10) is arranged between the two grooves/recesses (11).
2. Heating plate according to claim 1, characterised in that at least one further heating element (14, 15) is provided.
3. Heating plate according to claim 2, characterised in that a recess (11) is arranged between two heating elements (10, 14, 15).
4. Heating plate according to one of the preceding claims, characterised in that the base plate (7) is formed from glass, ceramic, glass ceramic, temperature-resistant plastic, aluminium or silicone as a base material.
5. Hair-styling iron (1) having at least one heating plate (5) according to one of the preceding claims.

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