Patent Publication Number: US-6701937-B2

Title: Hair shaping device, especially a steam styling tong

Description:
TECHNICAL FIELD 
     The invention relates to a hair-shaping appliance, in particular steam styling tongs. 
     BACKGROUND 
     JP-A-11 46839 discloses a gas-operated hair-shaping appliance, in which flame-free combustion of a gas takes place by means of a catalyst for heating up heating tubes in a combustion chamber. There is provided a steam-distributor chamber which is supplied with water by a liquid container. The liquid container is provided with an exchange valve, via which air flows in when water flows out of the liquid container. When not in use, the pressure in the liquid container can increase, for example, on account of heating. This may result in water passing, via the liquid-channeling device, into the steam chamber and, from there, then flowing into the steam-distributor chamber, where it ultimately passes outward via the through-passages. During the heating-up operation of the hair-shaping appliance, this may result in an increased formation of steam. Thus, a user may sustain burns if he/she picks up the appliance. 
     Outlets connected to the combustion chamber and through-passages connected to the steam-distributor chamber are formed in the drum. This may result in differing temperatures at various locations, since the temperature at the outlets is usually higher than the temperature at the through-passages. Furthermore, this hair-shaping appliance is expensive and complex to construct as a result of the combustion chamber being separated from the steam-distributor chamber. 
     An object of the invention is to develop a gas-operated hair-shaping appliance, in particular steam styling tongs, according to the preamble of patent claim 1 such that the above disadvantages are avoided and, at the same time, the construction and the assembly of the hair-shaping appliance are simplified and the production costs are reduced. Aspects of the invention are also intended to achieve uniform and/or freely selectable steam distribution over the circumference of the drum. 
     SUMMARY 
     In one aspect of the invention the steam can mix with the combustion gases coming from the catalyst to better effect in one common chamber and can heat up more uniformly. The steam and combustion gases pass out through commonly used through-passages, which may be formed uniformly around the drum. This results in a uniform hot stream of steam around the drum. In this way, the drum or the heating tube is also heated up better and more uniformly, because the common chamber can bound the drum all the way round from the inside. In order that no water passes into the common chamber, suitable means are provided according to an aspect of the invention. This is because if water droplets were to wet the catalyst, then considerable ignition problems would arise since a comparatively high level of ignition energy would have to be applied in order for the water located on the catalyst to be evaporated before the flame-free combustion process ignites the catalyst. A single collecting chamber for the combustion gases and the steam simplifies the construction of the hair-shaping appliance to a considerable extent and, in addition to the abovementioned advantages, reduces the production costs. 
     By virtue of the features of one embodiment, only through-passages are formed on the drum. The through passages are connected to the common chamber. Both the hot combustible gases and the steam pass through the through-passages, in the form of a mixture. 
     The features of another embodiment include means to prevent excess water from collecting in the evaporating device because, during the return stroke of the dosing device, the excess water is automatically sucked back into the liquid container. Even when the dosing device is actuated a number of times in quick succession, these actuations cannot result in the evaporating device overflowing since during the return stroke of the dosing or pumping device, on account of the “closed” liquid tank, excess water is always sucked back into the water tank via the liquid-channeling device. As a result of this embodiment of the invention, the appliance remains dry and no water can penetrate into the catalyst via the common chamber or pass out of the drum. Penetrating water would impair the functioning of the catalyst or would even prevent it from being ignited, since it would be necessary to first evaporate the water in the catalyst. The energy required to do this, however, is not present at the start of ignition. 
     According to the features of another embodiment, the dosing device comprises, on the one hand, a pressure/suction pump and, on the other hand, a closed liquid container with only one outlet. During the return stroke of the dosing or pumping device, the outlet performs the function of an inlet for excess water which collects in the evaporator chamber or still adheres to the liquid-channeling device as an excess droplet. Of course, it is also conceivable to integrate a further liquid container in the appliance, which is provided with a separately working liquid-channeling device that channels excess water back into the second container. 
     By virtue of excess liquid flowing back immediately into the liquid container from the evaporating device, the hair-shaping appliance can be held as desired in a user&#39;s hand without liquid passing out of the drum via the through-passages. This also results in a particularly economical water-discharging device. The liquid located in the liquid container is fully converted into steam without some of the water running out of the appliance unused. 
     The features of another embodiment are provided in order to improve the operation of the evaporating device further, and in order to prevent the water that is discharged by the dosing device during the actuation from escaping even when the hair-shaping appliance is in the horizontal position. The evaporator chamber forms a relatively large evaporating surface and, at the same time, it retains small water droplets to better effect. It is possible here for the chamber to be of plate-like, cup-like or pot-like design. 
     The features of another embodiment result in an embodiment of liquid-channeling device which does not expose the wick to an excessively high temperature. This increases the service life of the wick. It is thus no longer necessary for the wick to be pressed against the evaporating surface in order for water to be discharged in a metered manner. However, it is also possible, upon actuation of the dosing device, for the wick to come into contact with the evaporator plate and to be pressed against it slightly. 
     The features of another embodiment make it possible for the wick to transport both liquid and air in both directions. This arrangement allows straightforward metering of the liquid. It is not possible for the liquid to run out without the dosing device being actuated. 
     The features of another embodiment provide a large receiving surface for the liquid on the wick, with the result that, even when the liquid container is in the horizontal position, the wick is still supplied with sufficient liquid. This holds true even when the liquid container is almost empty. 
     The features of another embodiment render the distance between the free end of the wick and the evaporator-chamber surface small enough to enable, even in the case of a small droplet forming at the free end of the wick, for the droplet to come into contact with the evaporator-chamber surface and even to flow out onto the latter, and evaporate there. 
     The features of another embodiment bring about a particularly straightforward integration of the dosing device with the liquid container. Based on the piston stroke, a correspondingly large or small amount of liquid passes out of the liquid-channeling device. In the case of this arrangement, the piston has to be displaced automatically into its starting position, preferably by means of a spring, in order to enable an automatic suction stroke to be executed. 
     The features of another embodiment result in a particularly straightforward embodiment of the dosing device integrated in the liquid container. The elastically deformable wall can easily be actuated for discharging liquid; however, it also easily moves back automatically into its original shape again, on account of its elastic expandability, in order to allow the suction stroke to be executed without a user&#39;s intervention. The elastically deformable wall may be fastened on the liquid container, for example by injection molding, screw connection, adhesive bonding or in some other manner. It may also be designed as a molding with the liquid container. Although, in this case, the wall thicknesses should be coordinated with one another such that, upon actuation of the deformable wall, the liquid container itself hardly deforms. 
     In order that the dosing device can discharge considerable quantities of liquid, it is advantageous if the deformable wall is of an outwardly curved design. The elastically deformable material and the wall thickness of the deformable wall have to be selected such that, on the one hand, they can easily be moved by hand and, on the other hand, they produce a sufficient suction-stroke action in the chamber of the liquid container such that excess water, which may be present in the evaporating chamber or on the wick, can be sucked back into the liquid container sufficiently quickly via the liquid-channeling device. 
     The features of another embodiment are provided in order to ensure that water only flows into the evaporating chamber when the liquid-channeling device butts against the base of the evaporating chamber or, better, terminates a short distance in front of the chamber. The rigidity of the elastically deformable wall is thus selected to be high enough for the liquid container, initially without any marked elastic deformation of the wall, to be displaced counter to the force of the compression spring until the wick has reached its liquid-discharging position in the evaporating chamber. This ensures that even excess liquid which may occur during the return stroke can be channeled back into the liquid container via the wick. For easy displacement of the liquid container, the latter is fastened in a non-displaceable manner in an insulating sleeve, which is fastened in a stationary manner within the drum. In order to avoid thermal overloading of the liquid container, the insulating sleeve is preferably produced from plastic. 
     In another embodiment, in order to allow the deformable wall to be exchanged if it is worn, it may be connected to the liquid container by a thread, a clip device, or some other releasable connection. 
     The features of another embodiment are provided in order to enable the liquid container to be easily removed from the hair-shaping appliance to be filled with a liquid. The liquid container is preferably filled with water, water enriched with fragrances, hair-treating substances, or other materials. A locking device designed in accordance with the principle of a bayonet closure allows the liquid container to be quickly inserted and removed. In the locked position, the locking device releases the liquid container for further displacement in the direction of the evaporating chamber. At least one stub projecting radially on the liquid container initially engages in a recess, when inserted, and is then secured by rotation against dropping out automatically. The liquid container can be moved back and forth within certain limits in the longitudinal direction by means of a further recess adjoining the first recess. Instead of one stub, of course, it is also possible for two or more stubs to be formed on the circumference of the liquid container. Although, in this case, it is also necessary to introduce into the sleeve a corresponding number of recesses, which then cooperate with the respectively associated stub. This improves the guidance of the liquid container. 
     The features of another embodiment ensure that it is only when the liquid container has been removed from the hair-shaping appliance and the closure cap has been opened that it can be filled with water. The operation of removing the liquid container from the hair-shaping appliance, which is necessary for filling the liquid container, helps to prevent malfunctioning of, and thus possible damage to, the hair-shaping appliance, because a user is not required to hold the entire appliance under a water source during the filling operation. The forced separation of the liquid container from the hair-shaping appliance facilitates handling of the filling operation.In this case, the hair-shaping appliance can be set to one side and the liquid container, on account of it being smaller than the rest of the hair-shaping appliance, can be held more easily under a faucet or a container. 
     The features of another embodiment ensure that, following actuation of the dosing device, the liquid container is automatically moved back into its starting position by the force of the compression spring as soon as the actuating force applied to the elastic wall by a user decreases. 
     According to the features of another embodiment, the compression spring, in addition to serving as a restoring spring for the liquid container, also performs a retaining and sealing function. A sealing ring mounted on an external diameter of the compression spring butts with sealing action against the liquid container and seals the evaporator chamber in relation to the bore formed in the insulating sleeve and to the liquid container. The sealing ring butts with sliding action in the bore of the insulating sleeve to seal the evaporator chamber when the liquid container is displaced. 
     The features of another embodiment ensure that, if a water droplet is actually slung out of the evaporator chamber, it is stopped on the hot felt ring where it evaporates and then penetrates the felt ring in the form of steam. This prevents the functioning of the catalyst from being disturbed. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 shows, on an enlarged scale, a partial longitudinal cross-section of a front region of a hair-shaping appliance according to an embodiment of the invention with the dosing device being located in its non-actuated, starting position; 
     FIG. 2 shows a side view of a rotated portion of the hair shaping appliance including the insulating sleeve with the dosing device inserted therein and the evaporator plate before the portion is inserted into the drum; 
     FIG. 3 shows a partial longitudinal cross-section through the hair-shaping appliance according to an embodiment of the invention corresponding to FIG. 1, with the dosing device in the actuated position; and 
     FIG. 4 shows a side view of the insulating sleeve with dosing device and evaporator plate according to FIG. 2, with the dosing device in the actuated position according to FIG.  3 . 
    
    
     DETAILED DESCRIPTION 
     The hair-shaping appliance  1 , which is preferably designed in the form of steam styling tongs, comprises, according to FIGS. 1 and 3, a tubular drum  3 , which treats hair (not illustrated). The tubular drum  3  includes through-passages  2 . In a central section of the drum  3 , there is formed an evaporator plate  4 , which, according to FIGS. 1 and 3, has diametrically opposite crosspieces  5  which run to the right. Openings  6  are formed between the crosspieces  5 . The crosspieces  5  enclose a combustion chamber  7 , in which a tubular catalyst  8  is formed as part of a heating device  12 . Flame-free combustion of a gas (not illustrated) takes place during the heating operation within the combustion chamber  7 . The gas passes out of an outlet-valve device (not illustrated) of a cartridge (not illustrated) and flows into a mixing/regulating and valve device (not illustrated). 
     The catalyst  8  essentially comprises a tubular steel mesh with a surface coating which consists of platinum or palladium and on which the flame-free combustion takes place. Projecting at a free end  11  of the catalyst  8  are thin ignition filaments  9  which are produced from wire. The filaments  9  provide for easy ignition during start-up of the catalyst  8  and, thus, initiate the heating operation of the heating device  12 . Projecting into the opening  6  from right to left is a control rod  10 , which, based on the temperature, controls the feed of gas to the catalyst  8  via a valve device. 
     Opposite a base  76  of the opening  6 , an evaporating device  13  is arranged within the drum  3 . The evaporating device  13  includes an evaporator chamber  14 , designed as a blind bore  15 , with an evaporating surface  16 . The evaporator chamber  14  is part of the evaporator plate  4  and likewise runs concentrically in relation to the drum  3 . In addition, the evaporating device  13  preferably includes a felt or a similar air-permeable and water-permeable wick material fastened in an outlet  18  of a liquid container  19  to form a liquid-channeling device or wick  17 . A first free end  20  of the wick  17  projects at a border  21  of the outlet  18 . The wick  17  is compressed by the wall of a bore  22  firmly enough in order to be retained in a non-slip manner in the bore  22  of the outlet  18 . The wick  17  has a second free end  23  projecting into a liquid-accommodating, preferably water-accommodating, chamber  24  of the liquid container  19  in order to form a sufficiently large receiving surface for the liquid. 
     According to FIGS. 1 and 3, the liquid container  19  comprises a tube  25 , of which an outer end is provided with a dosing device  26 , while its other end, which is located in the drum  3 , is provided with a sleeve  27  on its base. The outlet  18  with the wick  17  is arranged in the sleeve  27 . The sleeve  27  projects into the tube  25  and is preferably screw-connected there with sealing action by means of a thread  28  or a bayonet closure (not illustrated). The sleeve  27  has a projecting annular collar  30 . An annular surface  29  of the annular collar  30  is directed toward the dosing device  26  and supports an O-ring  31 . The O-ring is pressed against a free end  32  of the tube  25  to produce a sealed connection between the sleeve  27  and the tube  25 . The O-ring  31  is retained in a stationary manner in an annular groove  33  formed in the sleeve  27 . This prevents the O-ring  31  from sliding down the sleeve  27  when the liquid container  19  is unscrewed to be filled. Sliding down of the O-ring  31  could cause the O-ring to go missing, thereby eliminating the seal of the liquid container  19 . 
     According to FIGS. 1 and 3, a sealing ring  35 , in a bore  36  of which a compression spring  37  is retained in a stationary manner, is supported on an end surface  34  of the annular collar  30 . The end surface  34  is directed toward the evaporator chamber  14 . The compression spring  37  has its other end supported on a base  38  of an insulating sleeve  39 . The sealing ring  35  is preferably produced from elastomeric material and, by way of its annular sealing surface  50 , slides, with sealing action, along an inner bore  51  of the insulating sleeve  39 . At the same time, the other end of the guide sleeve  35  butts with sealing action against the end surface  34 , causing an annular chamber  53 , which is connected to the evaporator chamber  14  via a bore  52 , to close with sealing action in the direction of the atmosphere. This is because an annular space  55  is provided between an outer surface  54  of the tube  25  and the inner bore  51 . This makes it possible for air to pass to the sealing surface  50  of the guide sleeve  35  via the annular space. The annular space  55  may be of very small dimensions in order to ensure tilting-free guidance of the liquid container  19  in the insulating sleeve  39 . 
     According to FIGS. 1 and 3, the insulating sleeve  39  is firmly connected to the drum  3 , preferably by crimping. During the crimping, material  40  of the drum  3  is pressed plastically into depressions  41  formed on the insulating sleeve  39 . FIGS. 2 and 4 show the insulating sleeve  39  before it is inserted into a bore  42  of the drum  3  and crimped. The insulating sleeve  39  is centered in the bore  42  by way of its outer surface  43  and strikes against the free end  45  of the drum  3  by way of its end surface  44 . Thus, the insulating sleeve  39  always has a fixed arrangement in relation to the drum  3 . The insulating sleeve  39  concentrically encloses part of the liquid container  19 , the sleeve  27 , and the evaporating device  13 . 
     Supported, according to FIGS. 1 and 3, on an annular surface  46  of the insulating sleeve  39  is an annular felt element  47 . An opposite side of the annular felt element  47  butts against an annular surface  48  of the evaporator plate  4 . The annular felt element  47  is clamped in between the two annular surfaces  46 ,  48  such that it always maintains this position in captive fashion. In order for it to be centered in the radial direction, an annular collar  49  projecting from the annular surface  48  engages on an inner surface of the felt element  47 . An end of the tube  25  which projects to the left out of the insulating sleeve  39  is provided with an opening  56 , which is closed by a stopper  57 . A cylindrical section  58  of the stopper  57  projects into a through-passage bore  59  of the tube  25  and is centered there. A base  60  of the stopper  57  is formed by a flexible diaphragm. Upon actuation of the stopper  57 , for example by a user&#39;s finger applying pressure to it from the outside, the diaphragm deforms in the direction of a chamber  24  such that the chamber  24  is reduced in size and liquid is delivered into the evaporator chamber  14  via the wick  17 . 
     An annular collar  61  is formed on the outer surface of the stopper  57  and is pressed with sealing action, by a retaining ring  62 , into abutment against an end surface  63  formed at the free end of the tube  25 . The retaining ring  62  itself is firmly connected to the tube  25  by retaining noses  64 , which engage resiliently in latching holes  65  formed on the outer surface of the tube  25 . This connection constitutes a type of clipping or snap-in device, in which the annular collar  61  is elastically deformed until the retaining noses  64  spring resiliently into the latching holes  65 . Thus, in the manner of a barb, the retaining noses  64  are not capable of sliding out of the latching holes  65 . The opening  56  of the tube  25  is closed with sealing action in this way. The diaphragm  60  and the cylindrical section  58  of the stopper  57  are preferably formed integrally from an elastic polymer material. The diaphragm  60  forms the pressure/suction pump and/or the dosing device  26  for the liquid container  19 . 
     As shown in FIGS. 1 and 3, a clamp  67 , which is generally customary in the case of such hair-shaping appliances  1 , butts against an outer lateral surface  66  in a top region of the drum  3 . The clamp  67  may be pivoted upward, in arrow direction Y, by hand on the right-hand side, about a point of rotation (not illustrated), in order to allow hair (not illustrated) to be wound around the outer lateral surface  66  of the drum  3 . The hair is then clamped in between the outer lateral surface  66  and the clamp  67  by the downwardly moving clamp  67 . The clamp  67  is of double-walled design. At its free end, the clamp  67  is closed in the forward direction by a stopper  71  engaging in a cavity  68  of its walls  69 ,  70 . The stopper  71  is preferably firmly connected to the walls  69 ,  70  by a crimping device  72 . The clamp  67  runs concentrically in relation to the outer lateral surface  66  of the drum  3 , as seen in cross section. Thus, the clamp  67  butts against the outer lateral surface  66  if there is no hair positioned in a gap  73 . In this position, the clamp  67  is more or less flush against the outer lateral surface  66 . The width of the gap  73  is at its smallest in this position. 
     FIGS. 2 and 4 illustrate the dosing device  26  the liquid container  19 , the insulating sleeve  39  and the evaporator plate  4 . These are illustrated as an installation part which has been removed from the drum  3  in order to more clearly show a bayonet closure  74  between the liquid container  19  and the insulating sleeve  39 . Formed on the inner bore  51  of the insulating sleeve  39 , in the front left-hand section according to FIGS. 1 to  4 , are diametrically opposite guide or insertion grooves  75  (illustrated by dashed lines in FIGS.  2  and  4 ). When the liquid container  19  is inserted into the insulating sleeve  39 , diametrically opposite stubs  77 , which project from an outer surface  54  of the tube  25 , engage the insertion grooves  75 . Following further displacement of the liquid container  19  according to FIGS. 1 to  4  to the right, the stubs  77  engage in a recess  78  formed on the insulating sleeve. 
     Upon further displacement in the direction X, the stub strikes against a ramp  79  of the recess  78  and, since the insulating sleeve  39  is fastened in a rotationally fixed manner in the drum  3 , the tube  25 , and thus the entire liquid container  19 , is rotated in the direction of rotation U, (which runs in the clockwise direction). Upon release, the liquid container  19 , with the stub  77 , is moved longitudinally parallel to the center axis, counter to the displacement direction X and without rotating, by the force of the compression spring  37  until the stub  77  strikes against a stop surface  81  of the recess  78 . This can be seen from FIG.  2 . In this case, the stub  77  engages behind a blocking protuberance  82 , which is formed on the stop surface  81 . This prevents the liquid container  19 , for example on account of vibrations acting on it, from being able to rotate automatically counter to the direction of rotation U, in which case the stub  77  could reach the guide groove  75  and drop out of the insulating sleeve  39 . The compression spring  37  thus always presses the liquid container  19 , and thus the stub  77 , with prestressing against the stop surface  81 . 
     According to FIGS. 2 and 4, the ramp  79  is adjoined by an end surface  83  which runs parallel to a center axis  80 . With a boundary surface  84  located opposite the ramp  79  and the end surface  83 , a gap  85  is formed in the recess  78 . Upon axial displacement of the liquid container  19  in the direction X, the stub  77  can engage until it strikes against a stop surface  86  and no further displacement of the liquid container  19  is possible, as FIG. 4 clearly shows. In this position, the free end  20  of the wick  17  terminates at a small distance in front of the evaporator surface  16 . The distance is preferably only a few millimeters. It is also conceivable, however, for the free end  20  of the wick  17  to strike against the evaporator surface  16  even in the actuating position illustrated in FIGS. 3 and 4. 
     Operation and functioning of the hair-shaping appliance  1  according to the invention are as follows: 
     1. Removal of the liquid container  19  from the hair-shaping appliance  1  and filling of said container with a liquid, preferably water: 
     According to FIG. 2, the retaining ring  62  is pressed firmly by hand in the actuating direction X such that the liquid container  19  is displaced to the right counter to the force of the compression spring  37 . The stub  77  lifts off from the stop surface  81  in the process. At the same time, the liquid container  19  is rotated in the circumferential direction U by hand until the stub  77  strikes against the boundary surface  86  of the recess  78  and is aligned with the guide groove  75 . On account of the prestressed compression spring  37 , when the hand is released from the retaining ring  62  and/or the diaphragm  60  of the liquid container  19 , the latter is displaced counter to the direction X and the stub  77  slides to the left in the guide groove  75  according to FIG.  2 . As soon as the prestressing force of the compression spring  37  has been used up, the liquid container  19  can then be removed by hand from the inner bore  51  of the sleeve  27  and, thus, from the drum  3 . The removed liquid container  19  comprises the dosing device  26 , the tube  25 , the sleeve  27 , the O-ring  31 , and the wick  17 . The compression spring  37  remains, with the sealing ring  35 , in the inner bore  51  since the right-hand end of the compression spring  37  has been pressed slightly into the bore  52  of the sleeve  27 . The other end of the compression spring  37  is seated in the bore  36  of the sealing ring  35 , with a small amount of prestressing. This also secures the sealing ring  35 . 
     The removed liquid container  19  (not illustrated) can then be opened by the sleeve  27  being unscrewed from the thread  28 . In this case, the O-ring  31  remains seated firmly in the groove  33  and, thus, cannot go missing. The same applies to the wick  17 , which has been inserted into the bore  22  under prestressing. This is also shown by individual ribs  89  projecting in the bore  22 . The tube  25  with its dosing device  26  can then be held under a faucet or a liquid-discharging location (not illustrated) and the tube  25  can be filled with a liquid via a freed through-passage bore  59 . The sleeve  27  is then screwed to the tube  25  again until such time as the O-ring  31  butts in a pressure-tight manner against the free end  32  of the tube  25 . In this position, liquid can pass outward only via the wick  17 . 
     2. Insertion of the liquid container  19  into the hair-shaping appliance  1 : 
     The liquid-filled liquid container  19 , according to FIG. 1, is inserted into the inner bore  51  of the insulating sleeve  39  with the wick  17  in front. It is necessary to ensure that the stub or stubs  77  engages/engage in the guide grooves  75 . In this position, the liquid container  19  is not initially rotatable. The liquid container  19  is then pushed into the insulating sleeve  39  until the stub or stubs  77  strikes/strike against the ramp or ramps  79 . Upon further displacement of the liquid container  19  in the direction X, the container is automatically rotated counter to the direction of rotation U by the stubs  77  sliding up the ramp  79 . When the liquid container  19  is pushed into the insulating sleeve  39 , the end surface  34  of the sleeve  27  strikes against the end surface  34  of the sealing ring  35  and, upon further displacement of the liquid container  19  in the direction X, the sealing ring  35  is carried along to the right and the compression spring  37  is prestressed in the process. It should be noted, at this stage, that two bayonet closures  74  may be formed diametrically opposite one another, for better centering of the liquid container  19 , in the insulating sleeve  39 . 
     Once the liquid container  19  has been rotated to a sufficient extent, and the compression spring  37  has been prestressed to a correspondingly high level, the manual force acting on the liquid container  19  can then decrease to the extent where the force of the compression spring  37  displaces the liquid container  19  counter to the direction X again until the stub  77  engages behind the blocking protuberance  82  and strikes against the stop surface  81 . Once this occurs, the position of the liquid container  19  according to FIGS. 1 and 2 has been reached and the hairshaping appliance  1  is then ready for operation. 
     3. Operation of the hair-shaping appliance according to the invention during the discharge of steam: 
     Once a valve device (not illustrated) has been rotated into its open position by hand, gas flows into the catalyst  8  and it is likewise possible, by activating a further ignition button (not illustrated), for the ignition device (not illustrated) to be ignited. On account of a combustion, the ignition filaments  9  achieve their operating temperature, i.e. they begin to ignite by the flame-free combustion. This high temperature is then transmitted to the catalyst  8 , which is activated in this way. 
     The evaporator plate  4  is then heated until the control rod  10  cuts back the gas feed. The desired operating temperature at the evaporator plate  4  is then automatically controlled by the control rod  10  by virtue of opening and closing the valve device. The heat of the catalyst which is produced in the combustion chamber  7  also penetrates, via the openings  6  (FIGS.  2  and  4 ), into a common chamber  87  formed between the evaporator plate  4  and the bore  42  of the drum  3 . This results in the bore  42  and, thus, the drum  3 , also being heated. According to an aspect of the invention, the common chamber  87  combines the combustion chamber  7  with the steam distributor chamber  91 . The combustion gases produced in the catalyst  8  are delivered, via the openings  6 , into the common chamber  87  and, from there, to the outside via the through-passages  2 . This operation takes place until such time as the hair-shaping appliance is sufficiently hot. 
     A user can then pick up the hair-shaping appliance  1  by its handle (not illustrated). The handle is formed on the right-hand side of the hair-shaping appliance  1  according to FIGS. 1 to  4 . The user may move the appliance  1  toward his/her head. The clamp  67  may be pivoted open and hair may be positioned in the resulting gap  73 . It is then possible for the hair to be wound around the outer lateral surface  66  of the drum  3 . 
     A user can then use a finger of his/her other hand (not illustrated) to press on the base  60  of the dosing device  26  until such time as the liquid container  19  is displaced in the direction X counter to the force of the compression spring  37 . In this actuating position, the base  60  of the diaphragm hardly deforms at all since the deformation force which is necessary for deforming the base  60  is greater than the force which is necessary for compressing the compression spring  37 . This means that the liquid container  19  is displaced in the direction X, counter to the compressive force of the compression spring  37 , until such time as the stub  77  strikes against the boundary surface  86  of the recess  78 , as can clearly be seen in FIG. 4 in particular. 
     If force then continues to be applied to the base  60  of the dosing device  26 , the base  60  deforms into the through-passage bore  59  of the tube  25  (although this is not illustrated in the drawing). With this deformation of the base  60 , the liquid located in the liquid container  19  is then forced through the wick  17  causing liquid in the form of droplets (not illustrated) to pass through the free end  20  of the wick  17 . Since there is only a very small distance “b” between the free end  20  of the wick  17  and the evaporator surface  16  in this position (FIG.  3 )—the distance being approximately 1 to 5 mm—the droplet comes into contact with the evaporator surface  16 . The droplet, therefore, evaporates, before it can drop off the wick  17 . If the base  60  is pressed firmly enough for a plurality of liquid droplets to pass out at the free end  20  of the wick  17 , then the evaporator chamber  14  is filled to a greater or lesser extent with liquid. The liquid can then partially or wholly evaporate, provided that pressure continues to be applied to the base  60  of the dosing device  26 . 
     The steam formed in the evaporator chamber  14 , according to FIGS. 1 and 3, is then guided into the annular chamber  53  where it penetrates the annular felt element  47 . Water droplets are restrained by the felt element  47  or wick  17 . Steam and water cannot pass into the annular space  55 , which is open to the atmosphere, since the sealing ring  35  is sealed in relation to the inner bore  51  and the sleeve  27 . Once the steam has penetrated the felt element  47 , it passes into the steam-distributor chamber  91  and, thus, [according to the invention] also into the common chamber  87 . The steam is heated up there again and leaves the through-passages  2  in the outward direction together with the combustion gases. This steam penetrates into a user&#39;s hair, heats the hair and, at the same time, wets it so that it can be shaped to better effect. 
     As soon as the pressure on the base  60  of the dosing device  26  decreases to a point that the pressure is smaller than the force applied by the compression spring  37 , the liquid container  19  is displaced to the left, counter to the direction X, until, in turn, the stub  77  strikes against the stop surface  81 . When the force is removed from the base  60 , the base  60  deforms again into the starting position illustrated in FIGS. 1-4. A negative pressure is produced in the chamber  24  of the liquid container  19  ensuring that the excess liquid in the wick  17  and/or in the evaporator chamber  14  (that is to say liquid which has not yet been converted into steam), is sucked back into the chamber  24  via the wick  17 . This prevents any more liquid from being evaporated than is desired by a user. 
     Through the actuation of the base  60  of the dosing device  26 , it is very difficult to meter the precise quantity of water which is to be evaporated in the evaporator chamber  14 . For this reason, it is possible, if too much liquid has passed into the evaporator chamber  14 , for example, on account of excessively pronounced actuation of the base  60  and/or of the dosing device  26 , for the liquid to be sucked back abruptly into the chamber  24  of the liquid container  19  via the wick  17 . (In this case, the steam delivery is adjusted in an abrupt manner.) This produces a hair-shaping appliance  1  with very economical water consumption for producing steam. 
     (When the hair-shaping appliance  1  is not in use) and when the hair-shaping appliance  1  is not used for a relatively long period of time, it is not possible for the liquid, which is still located in the chamber  24  of the liquid container  19 , to run out of the latter and pass out as non-evaporated water at the through-passages  2  or even to be able to pass to the catalyst  8  via the openings  6 . The latter possibility would render the next ignition operation difficult, or would even make it impossible to activate the catalyst  8 . For this purpose, an excessively high level of ignition energy would be necessary in order to drive the liquid out of the catalyst  8 . 
     According to an aspect of the invention, it is, thus, not possible for the liquid to run out of the liquid container  19  because the dosing device  26  closes the liquid container  19  with sealing action. The liquid can only run out via the wick  17  when the dosing device  26  is actuated and, during the return stroke, air flows into the liquid container  19  via the wick  17 . Since, however, the wick  17  is dimensioned such that, in the pressure-free state, no air can penetrate into the chamber  24  via the same, it is not possible for any liquid to run out of the liquid container  19  without external action. 
     When the liquid tank  19  is displaced, the base  60  is merely subjected to an axially directed force applied by hand. Rotation and, thus, the possibility of the liquid container  19  dropping out of the hair-shaping appliance  1  when the force is released are barely possible. The maximum displacement of the liquid container  19  is provided by the distance (a) between the stop surface  81  and the boundary surface  86 . This precisely defines the minimum distance (b) between the free end  20  of the wick  17  and the evaporator surface  16  (FIG.  3 ). 
     It should also be mentioned that the evaporator surface  16  is provided with a stub-like elevation  88 , of which the average diameter (d) is smaller than the diameter of the free end  20  of the wick  17  (FIG.  1 ). Furthermore, the stub-like elevation  88  is rounded at its free end in order for the wick  17  to be subjected to the action of as little heat as possible. This increases the service life of the wick  17 . The stub-like elevation  88  also advantageously serves to provide the largest possible evaporator surface  16 , by means of which the largest possible quantity of steam can be produced in a comparatively short period of time. 
     Once a curl (not illustrated) has been sufficiently subjected to the action of steam and heat, and has thus achieved a comparatively stable form, the clamp  67  can be opened by hand and the curled sections of hair can be removed from the hair-shaping appliance. The operation can then be repeated on further sections of hair.