EP0604463B1

EP0604463B1 - Instrument for lock decoloration of hair

Info

Publication number: EP0604463B1
Application number: EP92917639A
Authority: EP
Inventors: Giovanni Caron
Original assignee: S E R P A T Srl
Current assignee: S E R P A T Srl
Priority date: 1991-08-05
Filing date: 1992-08-06
Publication date: 1996-11-06
Anticipated expiration: 2012-08-06
Also published as: ITVA910024A1; DE69215100D1; DE69215100T2; IT1253421B; AU2441792A; EP0604463A1; ES2093273T3; WO1993002589A1; ITVA910024A0

Abstract

An instrument for selectively decolorating locks of hair compris e a pair of jaws (1, 2) capable of closing one upon the other through a pincers' movement and defining a channel therebetween into which a selected lock of hair, previously laid over one jaw may be gripped. An injection mechanism (13) injects a preestablished quantity of dyeing liquid inside the channel defined between the two jaws for wetting the lock of hair. Preferably one (2) of the two jaws has an internal surface contacting the hair which is electrically heated (17) for accelerating the dyeing process of the lock of hair. The instrument permits to perform a lock-by-lock treatment for producing a so-called coups-de-soleil effect without the need to use a protection cap for the rest of the hair.

Description

The present invention relates to an instrument for selectively decolorising locks of hair, i.e. for producing streaks or the so-called coups-de-soleil in the hair. Locks decolorisation is commonly practiced by hairdressers. Basically the hair must be decolorised selectively by locks while leaving unaltered the hair adjacent to the lock being treated. The treatment may consist of a decolorisation to remove the natural or pre-existing color of the hair and/or of a pigmentation of the separated out lock of hair to give to lock of the hair a desired color, different from the natural or pre-existent color. As it is well known to a skilled artisan, the process of color alteration of the hair takes place essentially through a decolorisation process, i.e. a removal, more or less total, of the natural pigment of hair in order to sensitize the so-decolorised hair to absorb and retain an artificial pigment. The two steps of the process take place substantially through a single treatment which consists in wetting the hair locks to be treated with a dyeing liquid which is commonly a mixture of pigments, stabilizers, carriers thickening agents and the like, as for example a mixture containing P-phenylenediamine, aminophenols, resorcine, α-naphthol, ammonia, isopropyl alcohol, carriers, to which, immediately before proceding to the treatment of the hair, a decolorising or bleaching agent is normally added. This decolorising or bleaching agent is commonly constituted by hydrogen peroxide or by a similar oxidizing compound. The hair must remain in contact with the dyeing mixture for a relatively long time, in the order of 15 to 40 minutes or longer. The decolorisation processes may be accelerated by exposing the hair wetted with the dyeing mixture to heat, commonly by treating the wetted hair under an hairdressing dryer. GB-A-1 128 647 discloses heating of hair wetted with a dyeing liquid mixture under a hood to promote the decoloration process. At the end of the treatment the hair must be accurately rinsed for removing the dyeing fluid while the treated hair locks have absorbed and fixed the pigment.
CH-A-287396 discloses an instrument for applying a dyeing liquid mixture to a lock of hair, in the form of a pincer
In view of the treatment conditions, it is evident the difficulty and complexity of the treatment when a selective dyeing of locks must be performed. The great difficulty is represented by the fact that the hair adjacent to the singled out locks must be accurately protected from coming into contact with the dye for the entire period of treatment, which, under the treatment conditions commonly used, may last up to forty minutes and longer. As a consequence, in order not to prolong eccessively the treatment time for completing the hair treatment, hairdressers utilize a technique which implies the application over the hair of a plastic cap provided with uniformely distributed small cuts or pin holes through which the hair locks are patiently extracted by means of a hook. This preparatory operation for the dyeing treatment is time consuming and often fastidious to the client because of inevitable accidental pulling of hair while the locks are being pulled out of the cuts of the cap. A fastidiousness, which of ten becomes more pronounced during the subsequent treatment of the pulled out locks because of a growing irritation due to the feeling of constriction that the cap produces.
Other less traumatic methods for treating a single lock of hair at the time have been attempted, all with unsatisfactory results especially because of an eccessive lengthening of the time necessary to complete the treatment on the whole head.
A main objective of the present invention is to provide an instrument which would permit to decolorise a single lock of hair at a time without the need for setting protective caps and at the same time reduce or maintain within economical limits the time necessary for performing the treatment.
This objective and other advantages are achieved by means of the instrument for decolorising hair selectively lock by lock object of the present invention.
Basically the instrument of the present invention is composed of a pair of jaws capable of defining a channel therebetween by closing one on the other through a pincers movement in order to grip between the two jaws a lock of hair which had previously been laid over one of the two jaws. One of the two jaws may contain a pad which may be wetted with a fluid dyeing mixture for decolorising hair, in order that when a lock of hair is gripped between the two jaws is pressed against the surface of the wetted pad and therefore is itself wetted with the dyeing mixture. Alternatively a lock closed between the two jaws may be wetted with a liquid dyeing mixture which is purposely injected through an injection port under the control of the operator. At least one of the two jaws may be provided with electrical heating elements, which may also be controllable by the operator, capable of heating to a preestablished temperature an internal surface of the jaws in direct contact with the hair of the lock gripped between the two jaws. It has been found that a lock of hair may be completely and satisfactorily decolorised in a total time which may vary between 40 seconds and about 3 minutes, i.e. compatible with the requirement of maintaining the total time for treating the whole head, within economical limits of normal professional hairdressing.
The outstanding shortness of the time necessary for decolorising each singled-out lock of hair is due to the fact that the heating elements are essentially brought directly in contact with the hair wetted with the dyeing mixture and may reach a peak temperature which may be adjustable between 60°C and 130°C. Upon the attainment of these temperature levels, though for short periods of time, the decolorisation process of hair is extremely enhanced and produces a complete decolorisation very quickly.
When one of the two jaws is provided with a pad to be saturated with the dyeing liquid, the pad may consist of a porous, substantially elastic mat of a material which will resist to the maximum temperature reached by the heating elements in contact with the hair. Pads constituted by mats or rollers of fibrous materials resistant to heat e.g. carbon fibers, rockwool fibers, fibers of PTFE or other thermoplastic polymer having a softening or degradation temperature above the peak temperature which may be reached by the heating elements of the instrument and which are rendered sufficiently hydrophilic by a superficial treatment or by coating the fibers, with a hydrophilic substance may be satisfactorily used in the instrument of the invention.
The different aspects and advantages of the instrument object of the present invention will become more evident through the following description of several embodiments and by reference to the annexed drawings, wherein:

Figure 1 is a schematic simplified view of an instrument of the invention;
Figure 2 is a schematic partial sectional view of the jaws of the instrument of Fig. 1;
Figure 3 is a schematic simplified view of a different embodiment of the instrument of the invention;
Figure 4 is a schematic partial sectional view of the jaws of the instrument of Fig. 3.

With reference to the Figures 1 and 2, basically the instrument comprises a pair of jaws 1 and 2, having a channel-like shape, capable of closing one against the other through a pincers movement, optionally one fitting into the other, in order to be able to grip therebetween a lock of hair, previously laid in the channel of the lower jaw 1. The two channel-shaped jaws may have any type of a somewhat elongate shape. In order to favor the laying of a lock of hair on a jaw, these may have a cross section which gradually widens from one end of the jaw which is functionally brought close to the scalp toward the opposite end. Moreover, at the two ends, the cross section of the jaws may funnel out, as depicted in Fig. 1.
The two jaws 1 and 2 are held at the end of two arms 3 and 4 of an elastic pincers 5, which may be suitably shaped in order to facilitate the use of the instrument with one hand (for example with the left hand) by the operator who with the other hand will select and separate a lock of hair to be treated by laying it on the lower jaw 1. Of course, a contrasting elastic force may also be provided by a suitable spring compressed between the two holding arms or by any other equivalent means.
In the embodiment shown in figures 1 and 2, the lower jaw 1 has the shape of an elongated trough, the two terminal pieces 6 and 7 closing up to a partial height the channel at the two ends of the jaw. The material of construction of the jaws 1 may be a sheet of a metal or alloy which is not corroded by the substances used during the treatment. A stainless steel, titanium or other resistant alloy may be used. The entire volume of the trough thus formed within the channel-shaped jaw 1, may be occupied by a porous and sufficiently elastic pad 8, which may be an elongated cushion or mat of an appropriate size of carbon fibers and/or rockwool fibers and/or PTFE fibers and/or fibers of a thermoplastic resin having a softening temperature greater than a maximum hair treatment temperature, i.e. greater than about 130 °C, or a mixture of these materials in order to obtain a pad having absorption, elasticity and antipasting properities. Functionally, the pad 8 is saturated with a fluid dyeing mixture (e.g. a dye + a hydrogen peroxide solution) in order to wet the hair of the lock closed between the jaws. The dispensing of an adjustable quantity of dyeing mixture in order to compensate for the quantity which is taken up by the hair and/or is evaporated during the heat treatment, may take place in a substantially automatic manner, through a dispensing manifold 9 purposely formed on the bottom of the jaw 1, which extends for the entire length of the jaw and communicates with the inner space of the jaw containing the pad 8 through a plurality of holes 10 uniformly spaced from each other along the entire length of the jaw. The liquid may be dispensed to the distributing manifold 9 through a flexible tube 11 connected to a bottom outlet of a dyeing fluid mixture reservoir 12 which may be conveniently mounted on the upper arm 3 of the pincers handle of the instrument.
An automatic dispensing of an adjustable quantity of fluid to the pad 8 may take place by means of a simple elastic bellows pump 13 provided with a suitable unidirectional valve 14 or more preferably of two unidirectional valves 14 and 15. When closing together the jaws 1 and 2, the bellows 13 is compressed thus causing a forced delivery through the tube 11, the distributing conduit 9 and the holes 10, of a preestablished quantity of fluid to the pad 8 which occupies the entire volume of the trough defined in the lower jaw 1. The delivered quantity of fluid may be volumetrically preestablished by adjusting the volume reduction of the elastic bellows 13 upon the closing of the pincers'arms 5. The valve 14 prevents the flowing back of the fluid into the reservoir 12. Therefore the delivered quantity at each stroke of the pincers may be precisely established and adjusted by means of a threaded ring 16 capable of determining a certain pre-compression of the bellows 13 in order to reduce or increase the quantity of fluid which is delivered at every stroke.
The upper jaw 2 has a shape complementary to the shape of the lower jaw 1 and has a length and width which may be smaller than the corresponding dimensions of the channel of the lower jaw 1, in order to permit the upper jaw 2, upon the closing of the pincers, to freely encroach into the channel-shaped jaw 1 and abut on the upper surface of the elastically deformable pad 8, thus compressing it together with the hair which may have been laid upon the pad.
In the embodiment shown in the figures, the upper jaw 2 contains electrical heating elements. As shown in the partial cross section of Fig. 2, these elements may be constituted by a plurality of cylinders 17, having a smooth external surface, preferably of a metallic material which is not corroded by the aggressive chemical compounds contained in the liquid hair-dyeing mixtures to be used. Stainless steel, titanium and similar corrosion resistant materials may be used. Each cylinder 17 is provided of an inner heating resistor, preferably electrically isolated from the outer metallic cylindrical sleeve. The internal heating resistor may be a paste resistor or a wound metal wire resistor. The two terminals of the heating resistor may conveniently constitute the mounting pins of the single heating cylinders 17. As schematically shown in Fig. 2, the channel-shaped body of the upper jaw 2 may be formed preferably of an electrically insulating material, e.g. ebonite or other isolating plastic material resistant to a temperature of about 130°C. On the two outer lateral faces of the jaw, conductive tracks 18 and 19 may be formed by incorporation, adhesion, deposition or similar technique of two metallic strips, for example of copper or of stainless steel or of titanium or of aluminum. To these two conducting bands present on the outer face of the two sides of the channel-shaped upper jaw 2, the terminal-pins 20 of each heating cylinder 17 may be connected. The two conducting tracks for the electrical supply of the heating resistors 18 and 19 may be commuted by use of a two conductor cable 22 which may be disposed along the internal face of the relative arm 3 of the pincers, emerging through the hole 21, for establishing a cable connection to a low-voltage socket of a control console of the instrument. Of course, through the same cable 22 may also be established a connection to a temperature control circuitry of the console of a thermocouple which may be installed within the upper jaw 2 near the heated surface of one of the heating cylinders 17.
The control of the temperature reached by the heated surface of the cylinders which is pressed into contact with the hair wetted with the dyeing fluid mixture may be performed in different manners. By placing a thermocouple or a similar temperature sensor within the jaws, the temperature may be adjusted and kept constant by means of a suitable control circuitry contained within a control console and capable of regulating the current passing through the resistors. Alternatively the heating may be manually controlled by the operator through a push button which may be installed on the pincers'arms 5. Through this push button the operator may determine a quick heating of the cylinders after having closed the pincers on the lock of hair separated out and disposed between the jaws of the instrument. In this case, the heating supply and control circuitry may be such as to provide a quick and time limited heating cycle. By acting on a push button control, the resistors may be supplied with a relatively high current such as to cause a fast rise of the temperature of the external surface of the cylinders from room temperature to a maximum temperature which may be predefined by the operator and which is reached in a preestablished period of time which may vary from several seconds to one or more minutes and at the end of the temperature ramp the control circuitry will provide to automatically interrupt the electrical supply to the heating resistors so that the temperature of the external surface of the heating cylinders rapidly falls again to room temperature. With such a kind of control, which may be programmed for a temperature ramp of several seconds, the operator may, if necessary, repeat the heating cycle on the same lock of hair in case an incomplete decolorisation is observed at the end of the first cycle, and so forth until attaining the desired result.
Of course, other systems for regulating the temperature may be employed in the instrument of the invention. These alternative control systems may also be selectable from a control console, according to need.
The cylindrical shape of the heating elements, disposed at regular intervals along the length of the jaws, is particularly advantageous for a particular mode of utilization of the instrument. According to this mode of operation, the open jaws are brought close to the scalp and a lock of hair of a desired thickness is separated from the mass of hair and laid over the lower jaw 1. At this point the two jaws are closed together and the operator may command the beginning of the heating cycle of the hair wetted with the dyeing treatment fluid, wait few seconds and begin to slowly draw the instrument away from the scalp while maintaining the jaws closed and the heating active, thus pulling away the instrument from the lock of hair slippingly gripped between the two jaws and completing the drawing motion in a time sufficient to produce the decolorisation of the hair, progressively along the entire length of the hair if the latter are longer than the length of the jaws. In this mode of operation, the heated cylindrical surfaces of the cylinders 17 run slowly over the wetted hair thus transmitting to them the heat necessary to cause a fast rate of decolorisation.
It is evident that both the means for wetting the lock of hair closed between the jaws as well as the means for transmitting thereto the necessary heat, may also be different from the ones depicted in the embodiment of the Figures 1 and 2. In particular the cushion-like pad 8 may be replaced by a plurality of roll-like pads, which may also be disposed transversally in respect to the length of the jaws 1. Similarly the heating surfaces which are brought into contact with the wetted hair may have different shapes and may be installed in the upper jaw 2 as well as in the lower jaw 1 or in both.
Of course the instrument of the invention may be realized in different shapes, which may be designed especially for treating long hair, or short hair or for performing periodical treatment on the growth portion of hair, close to the scalp.
Solely for an illustrative purpose, in Figures 3 and 4 a second embodiment of the instrument of the invention is depicted. The parts which are functionally similar to those of the embodiment of Figures 1 and 2 are indicated with the same numbers.
In the embodiment shown in Figures 3 and 4, the two jaws 1 and 2 have a semicylindrical shape and are substantially shorter than the jaws of the embodiment of Figures 1 and 2. According to this embodiment, the shape of the jaws is such as to exert a vice-like action on a lock of hair and the internal channel into which the lock of hair is tightened is substantially cylindrical and does not contain a dyeing-liquid wetting pad. The dyeing liquid is injected into the mass of hair tightened within the cylindrical channel defined by the two jaws 1 and 2 in a predetermined quantity sufficient for treating the lock. The injection of the dyeing liquid may take place in a manner similar to what has been described in relation to the preceding Figures 1 and 2 or may also be injected by means of a manual pump which may be acted upon by the operator according to need. As schematically depicted in the cross section of Fig. 4, in order to prevent an occlusion of the inlet port of the treatment liquid injected into the cylindrical channel defined between the two jaws 1 and 2 closed one against the other, which could be caused by an eventual precipitation of salts of other solid substances promoted by the relatively high temperature reached by the treatment liquid, the presence of a needle 11b, operatively fixed on the internal face of the upper jaw 2 and capable of passing through the orifice 11a at every stroke of the jaws may be contemplated in order to maintain open the injection orifice of the dyeing liquid.
In the cross section of Fig. 4 is also schematically indicated the heating electrical resistor R, which may be conveniently disposed within the upper jaw 2 and thermally coupled to the internal cylindrical face of the jaw which directly contacts the hair constricted into the cylindrical channel. Of course, also the internal face of the lower jaw 1 may be provided with similar heating means. Also in this case a thermocouple or alike sensor may be installed in proximity of the heated surface of the jaw or of the jaws and the generated electrical signal may be used for controlling the temperature reached by the instrument and optionally for maintaining constant such a temperature to a preadjusteabled value, which may be selected by the operator depending on the type of hair to be treated, by acting on selectors or push buttons of a control consolle to which the instrument is connected through a cable 21.

Claims

An instrument for decolorising hair selectively by locks by contacting a lock to be decolorised with a dyeing liquid mixture for a sufficient period of time to decolorise the hair of the lock from the root to the point of the hair, while preventing decolorisation of hair adjacent to the hair of the selected lock, comprising a pair of jaws (1, 2) capable of closing one on the other through a pincers' movement, at least one of said jaws being provided with a dyeing liquid mixture inlet port (10, 11a), characterized by the fact that
said jaws (1, 2) define a channel therebetween into which a lock of hair laid on one of the jaws is engageable from a point close to the scalp;

said port (10, 11a) is adapted to disperse said dyeing liquid mixture in said channel; and that the instrument further comprises means for selectively heating only the hair of the lock enganged in said channel and wetted with said dyeing mixture to a temperature sufficiently high to promote dyeing.
The instrument as defined in claim 1, wherein at least one of said jaws (1, 2) is provided with electrical heating elements (R, 17).
The instrument as defined in claim 1, wherein said jaws (1, 2) are functionally mounted at the end of two pincers'arms (3, 4).
The instrument as defined in claim 1, wherein at least a lower jaw (1) contains a pad (8) which is saturated with said dyeing liquid mixture, said pad (8) having the form of a porous elastic cushion extending substantially for the entire length of the jaw (1).
An instrument as defined in claim 2 and 4, wherein said jaw provided with electrical heating elements is an upper jaw (2) and said heating elements comprise a plurality of transversally oriented parallel cylinders (17) spaced along the length of the jaw (2) and mounted within a jaws'longitudinal channel for compressing with their electrically heated outer cylindrical surface the wetted hair against the surface of said pad (8) contained within the lower jaw (1).
An instrument as defined in claim 5, wherein each of said cylinders (17) is mounted by means of two pins (20) passing through lateral walls of a channel-shaped upper jaw (2), said pins (20) acting as electrical connection terminals of a heating resistor contained within each cylinder (17), the two ends of said pins (20) establishing an electrical contact with two conductors (18, 19) running along the outer face of said lateral walls of said channel-shaped jaw (2).
An instrument as defined in claim 6, wherein said mixture is distributed to said pad (8) contained within said lower jaw (1) through a manifold (9) defined on the bottom of said channel-shaped jaw (1) and communicating with the space occupied by said pad (8) through a plurality of holes (10), spaced along the length of said jaw (1), through a bottom of said space, the liquid being delivered inside said manifold through a flexible tube connection (11) with a liquid reservoir (12), by a volumetric pumping.
An instrument as defined in claim 7, wherein said liquid dispensing reservoir (12) is mounted on an upper arm (3) of said pincers (5).
An instrument as defined in claim 8, wherein delivery of a predetermined quantity of liquid to said pad (8) takes place by a volumetric pumping consequent of each closing stroke of the jaws (1, 2) by means of an elastic bellows (13) provided with unidirectional flow valves (14), which is compressed between the arms (3, 4) of said pincers'handle (5) at every closing stroke of the jaws (1, 2).
An instrument as defined in claim 2, wherein said electrical heating elements (R, 17) comprise at least an electrical resistor through which an electrical current sufficient to produce a desired rise of temperature of surface in contact with the hair, according to a preset temperature ramp, is passed.
An instrument as defined in claim 1, wherein said jaws (1, 2) have a semicylindrical shape and define therebetween a cylindrical channel, inside which a lock of hair is gripped, at least one of said jaws (1) is provided with a hole (11a) through which said dyeing liquid mixture is injected.
An instrument as defined in claim 11, wherein the other (2) of said two jaws is provided with a needle (11b) capable, upon a closing stroke of the jaws, to encroach through said injection hole (11a) of the dyeing liquid mixture in order to prevent occlusions.