EP0324695B1 - Hair roller for permanent waving - Google Patents

Abstract

The subject of the invention is a hair roller for producing permanent waves, comprising an elongated tubular support (1) and a heating cartridge (2) in the form of a cylindrical tube which can be heated separately and then inserted into the tubular support (1) after rolling-up of the hair (4). According to the invention, the heating cartridge (2) is associated with a shell (3) in the form of a cylindrical sector open over its entire length and mounted so as to pivot about an axis (20) orthogonal to the longitudinal axis (10) of the cartridge, on a support piece (24) provided at one end of the latter, the said shell being capable of assuming two positions, respectively an open manipulating position and a closed hair-holding position for which the shell (3) is re-closed over the tubular support (1), after insertion of the cartridge (2), covering the lock (4) rolled up on the said support (1). <IMAGE>

Description

The invention relates to a curler for the realization of permanent waves with heating of the hair.

Methods have been known for a long time for producing permanent waves of the hair in which the hair wound on curlers is impregnated with a liquid product and then subjected to heating for a certain time to increase the effectiveness of the product. This heating can be carried out simply in a dryer helmet but it is also possible to heat the curler itself.

Several decades ago, the curlers were heated electrically, but this had many drawbacks. This is why, subsequently, it was preferred to use devices capable of accumulating heat in order to then restore it to the coiled hair.

We can consider, for example, heating the curler itself in advance, but in this case, the operator is forced to handle hot curlers which forces him to limit the heating temperature and therefore the quantity calories accumulated.

It is therefore often preferred to associate with the curler a removable heating member.

In an embodiment commonly used, the heating member consists of a sleeve comprising two articulated parts forming a clamp which closes on the curler and the coiled hair.

The sleeves are made of a material which accumulates heat, for example rubber and are placed on heating bars on which the operator takes them one after the other. The fitting of the sleeves can therefore be done fairly quickly, after all the curlers are cold rolled up, which ensures a certain uniformity of the heating. However, such heating sleeves also have drawbacks; in particular, they are quite heavy and bulky and are likely to get crooked on the head by burning the scalp.

In another embodiment, the curler being constituted by a hollow tubular support, the heating member consists of a removable cartridge produced so as to accumulate heat in order to restore it thereafter to the coiled hair and which is strung in the curler after being heated separately. The heating element forming a heat accumulator can be constituted by an electrical resistance placed inside the cartridge (US-A-3250895) or else by a product which melts at a temperature which can be tolerated by the hair taking into account the insulating effect of the curler. In this case, the heating product is brought, by prior heating, above its melting temperature and, after threading the cartridge into the curler, it solidifies by releasing its latent heat of fusion (DE-A-2551379 ).

So that the operator does not risk being burned, the removable cartridge must be provided with a member making it possible to grasp it, for example an unheated part forming a button placed at one of its ends. However, to act quickly, the operator must be able to grasp the cartridge without special precautions and the button grip should therefore be relatively large. It may then unbalance the curler when the cartridge is threaded.

The subject of the invention is a curler of this type, that is to say comprising a removable heating cartridge, in which the cartridge is associated with a gripping member large enough to facilitate the handling of the cartridge and which does not however risk not to unbalance the curler.

Furthermore, it is necessary for the lock of hair to be kept rolled up on the curler and it is possible to use a pin, an elastic link or a clamp for styling the curler for this purpose. In particular, when the heating member consists of a rubber sleeve having the shape of a clamp, the hair is perfectly maintained and the heating can be carried out to the root.

One of the essential characteristics of the invention resides in the fact that the same member is used for gripping the cartridge and for holding the hair.

Indeed, in accordance with the invention, the heating cartridge is associated with a shell in the form of a cylindrical sector provided with an opening extending over its entire length and pivotally mounted around an axis orthogonal to the longitudinal axis of the cartridge on a support piece formed at one end of the latter, said shell possibly taking two positions, respectively an open position for which the shell is spaced from the cartridge and constitutes a gripping member allowing the manipulation thereof; and a closed position for maintaining hair for which the shell is closed on the tubular support, after introduction of the cartridge, by styling the strand wound on said support.

According to another particularly advantageous characteristic, the shell consists of a solid wall covering most of the curler and of the coiled wick, except the root, so as to concentrate on the hair the heat emitted by the cartridge. Preferably, the internal face of the shell is covered with a reflective surface to increase the capacity for concentrating heat.

The removable heating cartridge can be produced anyway allowing heat to accumulate, but it is particularly advantageous to use for this purpose a product capable of accumulating calories by prior heating and then returning them to the coiled hair, the cartridge being made up, for this purpose, of a cylindrical tube limiting an internal axial space closed in a sealed manner at its two ends and enclosing the heating product.

In this way, the tubular support can be constituted by a solid wall possibly pierced with orifices, the external face of which has a shape suitable for winding the hair and inside which an axial duct with smooth walls is formed. diameter substantially equal, apart from play, to that of the removable cartridge so that the heat is transmitted uniformly over the entire surface of the bore.

Preferably, the heating product is heated by prior heating above its melting temperature and solidifies, after threading the cartridge into the support, releasing its latent heat of fusion.

Until now, such a heating system had been provided for drying the hair (DE-A-2551379), that is to say with curlers used for styling and therefore having a diameter relatively large. The heating cartridge could therefore contain a sufficient quantity of product to give off the heat necessary for heating the hair.

But according to one of the particularly advantageous features of the invention, the heating cartridge, associated with a shell full of heat concentration on the hair, is used essentially for the production of permanent waves. In this case, the heating must continue for a fairly long time and the curler must be smaller. The heating cartridge must therefore have a very small diameter itself, for example of the order of 5 to 7 mm, and since it must be given sufficient rigidity, the heating product can only occupy a very small space . We should therefore normally have used another heating method for a curler of this type, for example by making the cartridge in the form of a solid rod of a material allowing heat to accumulate. But then the heating would be of short duration.

However, surprisingly, it was possible to find products having on the one hand the required melting temperature, that is to say between 50 and 120 ° C so as not to risk to burn the hair and on the other hand a latent heat of fusion of at least 600 J / cm³ allowing to release the desired amount of heat for the necessary time, taking into account the volume of product that can be placed in the cartridge. Such a heating product can consist, for example, of a molten salt such as barium hydroxide or stromtium.

However, the invention will be better understood from the following description of a particular embodiment, given by way of example and shown in the accompanying drawings.

Figure 1 is an axial sectional view of the tubular support.

Figure 2 is a side view, partly in section, of the removable cartridge.

Figure 3 is a side view, partly in section, of the shell.

Figure 4 is a cross-sectional view of the tubular support.

Figure 5 is a cross-sectional view of the shell cartridge.

Figure 6 schematically shows the introduction of the cartridge into the coiled curler.

Figure 7 schematically shows the installation of the sleeve after introduction of the cartridge.

Figure 8 is a cross-sectional view of the entire curler.

In the example shown in the Figures, the curler therefore consists of a tubular support 1, a removable heating cartridge 2 and a shell 3 shown respectively in Figures 1, 2 and 3.

The support 1 consists of an elongated plastic tube, the outer face 11 of which advantageously has a curved shape, thinner in its central part than at the ends so as to facilitate winding and holding the hair. This shape is moreover well known and one of the advantages of the invention lies in the fact that it is possible to apply it to curlers of normal shape and size whereas, until now, curlers for interior heating were larger and usable only for styling.

The curler preferably consists of a solid wall 12 inside which is formed an axial duct 13 limited by a smooth wall 14. Transverse orifices 15 distributed along the curler allow the interior to be placed in communication and the outside of the latter.

The removable cartridge 2 shown in FIG. 2 consists of a hollow plastic tube 21, closed at both ends so as to limit a sealed internal space 22 which is filled with a heating product 23. At the one of its ends, the tube 21 is fixed to a support piece 24 which may have the form of a plate of circular section.

Two diametrically opposed pins 25 are fixed on either side of the plate 24.

The cartridge 2 is associated with a shell 3 consisting of a smooth wall 31 of plastic material, in the form of a cylindrical sector whose smooth internal face 33 has a diameter D₂ greater than the maximum diameter D₁ of the curler and which is provided, on all of its length, opening 30 of width l slightly less than the diameter of the coiled wick.

In addition, the shell 3 is provided at one of its ends with two diametrically opposite orifices 32 in which the pins 25 of the support piece 24 can engage, as shown in cross section in FIG. 5.

The pins 25 thus form two aligned pins defining an axis of rotation 20 around which the shell 3 can rotate. The shell 3 can therefore take two positions, respectively an open position for which the shell 3 is separated from the cartridge 2 and a closed position for which the shell 3 covers the cartridge.

The operation can take place as shown in Figures 6 and 7.

The hair 4 is wound in strands on the tubular supports 1 which, as indicated, can have the usual shape and dimensions of conventional curlers and have on their external face 11 means for hanging the hair such that, by example, small protrusions 16.

This is how the hair is rolled up on all the curlers. During this time, the removable cartridges are heated, for example in an oven, in a double boiler, on an electric appliance or in any suitable way. During heating, the shell 3 is opened so as to be placed in the extension of the cartridge 2 as shown in FIG. 6.

In this position, the shell 3 constitutes a gripping member of sufficiently large size to be easily grasped by the operator and not likely to be heated, even by conduction.

One can thus introduce one after the other the cartridges previously heated in the conduits 13 of each of the supports 1 then, as shown in Figure 7, rotate the shell 3 around the axis 20 for it style the curler and the curled lock.

The cartridge 2 thus being introduced into the conduit 13 which has substantially the same diameter, apart from the sliding clearance, the heat is transmitted from the cartridge 2 to the tubular support and to the hair by radiation but also by conduction since, in practice, the cartridge is in contact with the curler over its entire length. However, it has been found that the mode of transmission by radiation may be sufficient and, depending on the case, it is also possible to use curlers in which the cartridge is kept at a distance from the wall by centering members such as, for example, two or three spaced rings.

The shell 3 is made of a rigid material which is elastically deformable so that, when it is closed on the wick 4 wound on the curler, the width l of the slot 30 increases slightly. The shell then tightens on the wick which it surrounds practically to the root by exerting a slight pressure. Because it consists of a solid and smooth wall 31, the shell 3 therefore makes it possible, according to one of the essential advantages of the invention, to concentrate the heat radiated by the cartridge 2, the heating thus being produced both from the inside and from the outside.

In addition the evaporation of the perm liquid is limited and the hair remains moistened longer.

To increase the effect of heat concentration, in a preferred embodiment, the internal face 32 of the shell 3 is entirely covered with a reflective surface 35 which may consist of a glossy coating such as a sheet of foil. aluminum simply bonded to the internal face 2 in a particularly simple and inexpensive embodiment.

It will be noted that the elasticity of the wall 31 constituting the shell 3 facilitates the removable mounting of the shell 3 on the support part 24 by engagement of the pins 25 in the orifices 32.

On the other hand, the support piece 24 consists of a circular plate of the same diameter as that of the internal face 33 of the shell which therefore applies exactly to the circular lateral wall of the plate 24. The latter has a thickness e sufficient to result in a slight blocking of the shell in the open or closed position in alignment with the cartridge, the elasticity of the wall 31 allowing the lateral edges 34 to move apart during the rotation of the shell.

As indicated, the invention can be applied to curlers of conventional shapes and dimensions whose diameter can range, for example, from 6.5 to 12 mm. However, since it is necessary to deduce therefrom the thickness of the tubular support 1 and that of the wall 21 of the cartridge 2, the internal chamber 23 in which the product of heating is particularly small. We should therefore have feared that we would not be able to obtain a sufficient temperature and heating time with such a small quantity of product capable of accumulating heat. However, we have managed to find products capable of accumulating a sufficient amount of heat in such a small volume. In addition, since the hair is rolled up cold and the cartridge is not directly touched for introduction into the curler, the heating product can be brought to a temperature slightly higher than in the case of classic curlers with internal heating.

We will therefore preferably use a product whose melting temperature is of the order of the maximum temperature that can be given to the cartridge, taking into account the heat loss between the latter and the outside face of the curler and the temperature that the hair and the head can withstand. For example, a product will be chosen whose melting temperature will be between 50 ° C. and 120 ° C.

The heating product contained in the space 23 is therefore melted during the preliminary heating of the cartridge and solidifies after introduction into the curler, giving the latent heat of fusion to the hair. This results in a particularly efficient heating mode for a small volume. In addition, the amount of heat thus released is substantially constant and, in particular, does not depend on the prior heating time. It is thus possible to precisely control the heating conditions and, consequently, the efficiency of the ripple treatment.

In addition, it has been possible to find products having a latent heat of fusion of at least 600 J / cm³ which makes it possible to obtain the desired temperature and heating time despite the small quantity of product placed inside the space 23 of the heating tube. For example, one can use as heating product a barium hydroxide whose melting temperature is 80 ° C and the latent heat of 600 J / cm³ or a Strontium hydroxide whose melting temperature is 88 ° C and the latent heat of 650 J / cm³.

The heating product will generally consist of a molten salt, but other products could be used, as long as the desired thermal characteristics are obtained.

However, it is also necessary that the product is compatible with the material of which the tube 21 constituting the cartridge 2 is made and which must on the one hand not react with the product because a gaseous release could produce an explosion and, on the other hand , have sufficient mechanical strength for the wall 21 to have a reduced thickness and nevertheless withstand the pressure resulting from the change of state. It is also necessary that the cartridge has a relatively reduced coefficient of expansion so as to slip into the axial duct 13 with a simple clearance necessary for sliding.

Of course, the embodiment which has just been described has been given by way of example only and could be subject to variants without departing from the protective framework defined by the claims.

In particular, thanks to the small size of the removable cartridge, it is possible to adapt the invention to curlers of all shapes. Similarly, the shape of the shell, which is not necessarily circular, and the method of mounting on the cartridge could be modified.

The reference signs inserted after the technical characteristics mentioned in the claims, have the sole purpose of facilitating the understanding of the latter, and in no way limit their scope.

Claims (12)

1. Hair roller for permanent waving, comprising a long tubular support (1) around which a lock of hair (4) is rolled and delimiting a hollow space (13), and a heating cartridge (2) in the form of a cylindrical tube, said cartridge being heated separately and then introduced into the hollow space (13) of the tubular support (1) after the hair has been rolled onto said support (1), characterised in that the heating cartridge (2) is associated with a shell (3) in the form of a cylindrical sector provided with an opening (30) extending along its length and which pivots about an axis (20) orthogonal to the longitudinal axis (10) of the cartridge, on a support part (24) provided at one end of said cartridge, said shell being capable of assuming two positions, respectively an open position in which the shell (3) is distanced from the cartridge (2) and constitutes a gripping device, and a closed position for holding hair in which the shell (3) closes onto the tubular support (1) after the cartridge has been introduced (2), thus covering the lock of hair (4) rolled onto the said support (1).
2. Hair roller according to claim 1, characterised in that the shell (3) is made up of a solid wall (3) covering the entire outwardly-facing portion of the hair roller (1) in such a way so as to concentrate the heat emitted by the cartridge (2) onto the rolled lock (4).
3. Hair roller according to claim 1 or 2, characterised in that the support part (24) is made up of a circular plate of a diameter substantially equal to the inside diameter of the shell (2) and on which two diametrically-opposite studs are fixed forming two aligned pivots which engage in holes (32) provided in the shell (3) in such a way so as to form an axis of rotation of said shell (3).
4. Hair roller according to claim 3, characterised in that the shell (3) is made up of a rigid wall (31) that can be elastically deformed to allow, on the one hand, the studs (25) to engage in the holes (32) and, on the other hand, the shell (3) to close onto the rolled locks and to lightly clamp the locks as close as possible to the roots.
5. Hair roller according to claim 2, characterised in that the inside face (33) of the shell (3) is covered with a reflecting surface (35).
6. Hair roller according to any one of the preceding claims, characterised in that the heating cartridge (2) is made up of a cylindrical tube delimiting an internal axial space (22) that is sealingly closed at its two ends, and in which a heating product (23) is enclosed which is capable of accumulating calories by previous heating and give them up to the hair rolled on the tubular support (1) after the cartridge (2) has been fitted.
7. Hair roller according to claim 6, characterised in that the tubular support (1) comprises a solid wall (12) whose external face (11) is suitable for winding on hair, and on the inside of which an axial smooth-walled bore is provided whose diameter, taking play into account, is substantially equal to that of the removable cartridge (2) in such a way that the heat is transmitted uniformly over the entire surface of the bore (13).
8. Hair roller according to claim 7, characterised in that holes are provided in the solid wall (22) of the tubular support (1).
9. Hair roller according to claim 6, characterised in that the heating product (23) is heated by prior heating to a temperature above its melting temperature and solidifies after the cartridge (2) has been fitted onto the support (1) by releasing the latent heat of fusion.
10. Hair roller according to claim 9, characterised in that the melting temperature of the heating product (23) is between 50°C and 120°C.
11. Hair roller according to claim 9, characterised in that the latent heat of fusion of the heating product (23) is at least 600 J/cm³.
12. Hair roller according to claim 9, characterised in that the heating product (23) is a salt in a melted state such as a barium or strontium hydroxide.

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