EP0954229A1 - Manual dispenser of fusible substance in particular of depilatory wax - Google Patents

Abstract

The invention concerns a manual dispenser of fusible substance, in particular of depilatory wax (5), comprising a case (10) forming a manual prehensile organ inside which is arranged a reservoir (12, 16, 18) of solid granulated fusible substance or in the form of a cake and means (30) for heating this fusible substance. More particularly, heating means (74) for initial fast melting of the wax are arranged in substantially homogeneous manner in the whole volume of the reservoir, or (32, 50) along one or several surfaces capable of passing in a mobile way substantially through the whole reservoir. In a first embodiment, the heating means are in the form of a grid (32, 50) formed by resistive heating wires initially arranged against one side of the reservoir and capable of moving to the opposite side. In a second embodiment, the heating means are made up of a resistive electric wire (74) arranged in a batch of substantially homogeneous loops in the volume (70) of the reservoir.

Description

 HAND MELT DISPENSER, IN PARTICULAR HAIR REMOVAL

TECHNICAL FIELD The present invention relates to a hand-held dispenser of hot-melt material, in particular depilatory wax, but which can also be a cream, an ointment, a glue or a varnish. By hot-melt material is meant all types of material taking a solid, semi-solid or pasty physical state at room temperature, and transforming into a liquid state under the action of heat, which then allows, among other things, its spreading in a thin layer. In this dispenser, the material stored in solid form at room temperature can be subjected to a heat flux to change to a fluid or even liquid state for distribution in the form of a thin layer.

BACKGROUND ART Usually, a dispenser comprises a housing forming a manual gripping means, inside which is formed a longitudinal reservoir of solid hot-melt material, such as wax in granules or in the form of a loaf. In the simplified versions, this reservoir opens into an intermediate conduit ending in a spout for depositing the layer directly on the application surface, or in an intermediate volume closed by a layer transfer roller.

The reservoir is in thermal relation with heating means for melting and then keeping all of the wax melted so that, once it is liquid, it flows out of the distributor in the form of a strip more or less thick depending on the speed of movement of the dispenser above the application surface: usually the skin of the user. Once the strip of wax is applied to the skin, a strip of gauze or plastic is deposited thereon, becoming integral with the wax once it has cooled and solidified. Tearing off the strips causes the trapped hairs to be extracted.

For example, the roller distributor according to document FR-A-2 520 601 is previously installed in a heating sleeve within a support box all the time necessary for all of the wax contained in the tank to melt. The waiting time is particularly long.

In the variant of a roller distributor according to document FR-A-2 706 261, the tank made of aluminum comprises a central diffusion fin, and is heated by an electrical resistance placed against one of its longitudinal walls. It is also advisable, in this case, to wait until all of the wax contained in the tank is melted before being able to use this dispenser.

In the roller distributors according to documents EP-A-499,317 and US-A-3,103,689, a single electrical resistance is arranged in the intermediate zone little above and parallel to the roller. If desired, the resistance is supplemented by a fin oriented towards the roller to also heat it. Starting can only start when all the wax present in the adjacent part of the tank and in the intermediate zone is melted.

In summary, with these simplified versions of dispensers, depilation can generally only begin when all of the wax present in the reservoir and in the intermediate duct ending in a spout, or in the intermediate zone at the outlet from which is located the roll, was first melted. However, the wax being usually heated at its periphery, or even only on one of its sides, the heat has great difficulty reaching the core of the wax bread or the volume of granules, given its low thermal conductivity. This overall melting then involves a significant and detrimental waiting time after the heating has been started, since it prevents rapid depilation when the user is pressed.

In more elaborate versions of dispensers, the reservoir includes means for pushing the end of a wax stick through a hot nozzle whose temperature is controlled and whose orifice opens onto a duct. intermediate terminating in a spout for depositing the layer directly on the application surface or in an intermediate volume terminated by a layer transfer roller.

In document EP-A-0 055 157 is described such a type of dispenser particularly intended for the depilation of the face, and in which the wax in the form of stick contained in a reservoir is pushed manually in a conduit of which the first rectilinear part is surrounded by a heating resistor. Once the wax has melted, it flows into the second bent intermediate part of the conduit opening into a dispensing orifice. In order to prevent the molten wax from cooling during its passage through the second part, this duct is made of a material which is a good conductor and accumulates heat.

In document US-A-1 449 517, a stick of hot-melt material is manually pushed with a thumb wheel into a heating intermediate nozzle of conical section reducing towards the outlet. This heating nozzle is also composed of a solid metallic material, therefore takes a long time to heat and has high thermal inertia.

Document FR-A-914 405 describes an electric distributor for producing wax seals. In this embodiment, there is an intermediate distribution neck downstream and relatively distant from the heating means disposed at the outlet of the tank containing the stick.

Again, in these elaborate dispensers, the wax is heated at its periphery and the heat has great difficulty reaching the core of the stick, given its low thermal conductivity. In addition, the heating means generally have a non-negligible thermal inertia. This leads to locally overheating the wax to accelerate the heat transfer, therefore to aggravate the inertial effects of the heating element, and to take risks on the final application temperature.

The use of this type of dispenser is then delicate because, when the heating means, the intermediate duct and / or the nozzle do not cool instantly causing the wax to continue to melt and to flow out of the tank for a few moments. This additional wax then sticks against the walls of the nozzle and other adjacent intermediate walls. This makes subsequent start-ups difficult because it is then necessary to wait until not only the heating nozzle has resumed its working temperature, but also that all the downstream wax present in the distribution part is also melted to restart, at the risk that the whole of the stick softens and makes the dispenser unusable by a complete glaze.

STATEMENT OF THE INVENTION

The object of the present invention is to produce a hand-held dispenser of hot-melt material, in particular depilatory wax, in which the melting at start-up of all of the wax in granules or in solid bread stored in the tank is much faster than 'before, this to allow a first distribution of wax as quickly as possible.

As before, the construction of the dispenser must be such that the thermal inertia does not affect the operation, in particular when this dispenser ends with a nozzle for direct distribution of the wax on the application surface or with a transfer roller. and application.

The structure of this dispenser should however be kept as simple as possible to ensure reliable operation over time and to keep production and assembly costs at a reasonable level.

These purposes are achieved in a hand-held dispenser of hot-melt material, in particular depilatory wax, comprising a housing forming a manual gripping means inside which is provided a reservoir of solid hot-melt material in granules or in the form of a bread as well as means for heating this hot-melt material because all or part (of starting) of these heating means is arranged in a substantially homogeneous manner throughout the volume of the tank or in one or more several surfaces capable of movably traversing substantially the entire tank.

By "homogeneous arrangement" in a plane or a volume is meant an arrangement by which the heating means are substantially identical, uniform, per unit of surface or volume to deliver practically constant heating at each point of the plane or volume. .

These additional heating means being on the one hand homogeneous, and residing on the other hand in or passing through the whole of the wax bar, can then be particularly powerful so as to melt this wax very quickly without risk when the dispenser starts. Once the wax has melted, these internal start-up heating means in the reservoir can be stopped and set aside to allow the wax to flow towards the outlet, conventional lateral heating means then ensuring that the wax is simply held in place. melted state. Alternatively, these internal heating means can themselves be set at a lower power by simply keeping the wax in the molten state.

In the remainder of the description, with reference to an example of a vertical cylindrical tank of rectangular section open upwards, a "longitudinal section seen from the front" defines a longitudinal surface parallel to the largest vertical side, by "longitudinal section seen on the side "a longitudinal surface parallel to the lateral side corresponding to the thickness of the reservoir and of the wax bar, and by" cross section "a surface perpendicular to the longitudinal vertical axis. The closed side of the tank opposite the outlet will be called "bottom".

According to a first embodiment, the heating means are in the form of a grid formed of resistive heating wires initially arranged against one of the sides of the tank and capable of moving to the other opposite side.

The homogeneous heating means then boil down to a simple heating resistance with meshes or parallel wires which is easy to produce and leaves passages for the wax once it has melted. The heat dissipated by this grid is easily controllable depending on the intensity of the current flowing through it. Thus, as it melts, the wax passes through the grid allowing it to progress towards an area that is not yet melted. It can then be seen that the temperature of the grid is automatically adjusted to a value slightly above the melting point of the wax, the electric power supplied conditioning the quantity of molten wax per unit of time, therefore the speed of movement of the grid at through bread. In addition, this resistance may be thin, therefore not very thermally inert.

According to a first variant of the first embodiment, the cross section is constant all along the tank and the heating means are a transverse grid with meshes of dimensions equal to or slightly smaller than those of the section, this grid being moved from the bottom of the tank towards the outlet, then back towards the bottom, by means of displacement of the grid. This arrangement resembling that of a plunger in a syringe is relatively logical and proven.

Usefully, the displacement means comprise a rod passing through the bottom of the reservoir and coupled either by an articulated rod, or by a transverse slide to a crankshaft or to an eccentric stud of a wheel driven in rotation by a spring or electric motor. This mechanism is relatively simple and lends itself rather well to mass production at reduced costs.

Useful then, the rod comprises a first conductive part permanently connecting the grid to an electrical supply contact located at the passage of the rod through the bottom of the tank, followed by a second insulating part connected to the connecting rod or to the slide , the periphery of the grid being in contact with the metal walls of the tank. This arrangement makes it possible to simply feed a grid, although it is mobile throughout its path, and this even under a high intensity providing the electrical power necessary to ensure the rapid melting of the wax. Usefully, a limit switch is arranged near the bottom dead center of the connecting rod, slide or lug, to stop the heating of starting power when the grid is back at the bottom of the tank, and, if desired, to initiate a backup heating heater for the melted wax.

According to a second variant of the first embodiment, the heating means comprise a longitudinal grid consisting of a series of close parallel bimetallic strips arranged side by side between two electrodes extending respectively along two opposite edges of the grid. Alternatively, the grid consists of a single sinusoidal bimetallic strip passing alternately from a support along one edge to another support along the opposite edge.

By bimetallic strip is meant a strip formed by two integral metal strips, for example joined flat, and each having a different coefficient of expansion, such as steel and copper, so that this bimetallic strip bends under the effect of heat, especially that dissipated by electrical energy passing through it.

Then, the reservoir is given the geometry corresponding to the volume traversed by this bimetallic grid when it deforms under the influence of its rise in temperature close to that of melting of the wax. This arrangement is particularly remarkable in that it elegantly overcomes any movement mechanism of the grid, which allows a considerable saving of space, either that the distributor becomes smaller, or that the tank is enlarged.

If desired, the width, therefore the resistivity, of the bimetallic strip (s) is slightly variable in the direction of the length of the grid, this width being however identical within each successive section of surface extending from a lateral edge to the other of the grid.

Then, the value of the substantially constant heating means within a lateral surface section is on the other hand modulated along the grid as a function of the volume of wax to be melted, that is to say as a function of the thickness. of tank and / or wax bread, in correspondence with this section. This characteristic finds all its advantage in the case of a transverse section tank evolving longitudinally.

According to a first embodiment, the longitudinal section seen from the side of the reservoir is in the form of a lens, and the longitudinal bimetal grid is articulated in rotation around the first lateral support / electrode, or around an adjacent parallel axis, at the level from the outlet of the reservoir, for example at the axis of the roller, the opposite lateral support / electrode being guided in longitudinal sliding at the bottom of the reservoir; or vice versa, the first support / electrode being articulated at the bottom of the tank.

According to a second embodiment, the longitudinal section seen from the side of the tank becomes triangular at its bottom, and the longitudinal bimetallic grid is fixed only at the bottom of the tank by its corresponding support / lateral electrode.

This range of embodiments allows optimization of the heating throughout the mass of the bread or block according to the thermal parameters of the different waxes and other hot-melt products.

In either of the variants, the outlet from the reservoir can lead to a transfer and application roller mounted on a retractable cradle in rotation or in translation. This arrangement allows the wax to be easily loaded into the reservoir by passing it through the wide outlet.

According to a second embodiment, the heating means are a resistive electric heating wire arranged in a bundle of loops which is substantially homogeneous in the volume of the tank.

As an alternative, the heating means can be a loose foam made of resistive electric heating material, this foam being supplied by two opposite electrodes. By "loose" foam is meant a foam which, unlike a tight foam, has large communicating cells, therefore very high porosity. This type of metallic foam is for example already used in the field of battery electrodes.

The heating means being thus already present at every point of the wax block, the latter can be melted extremely quickly in one piece by applying an adequate electric power. We can then describe it as a "flash" heating by analogy to the bulbs used in photography.

Preferably, the wire or the foam of the heating means are flexible, and the reservoir comprises means for pushing the wax towards the outlet, the heating means then being compressed. This allows the dispenser to be used in a better controlled manner in all positions, especially vertically with the outlet facing upwards for treatment of the armpits or the face. Then, the wire or the cells of the foam being fine, these heating means can also have a low thermal inertia, that is to say that they are unlikely to store calories and can cool very quickly after stop the maintenance heating to prevent the wax from continuing to flow when the dispenser is stopped.

According to a preferred embodiment, the reservoir is a removable cylindrical cartridge, one end of which is closed by a sliding piston head and the other end ends either with a spout or with a dispensing roller, the dispenser associated with a piston pushed forward in a cartridge receptacle, and this by a spring under the control of a mechanism. The cartridge usefully has an upper collar for fixing to the distributor, this collar also having a function of isolating the wax for the distributor.

The sale and handling of wax in the form of disposable refill cartridges are then greatly facilitated, in particular because the flange prevents fouling of the distributor.

For example, this distributor control mechanism may include a wire from being wound on a drum driven by an internal spiral spring when the piston spring is compressed, as well as a drum retaining lever when the wire is unwound by being driven by the piston pushed by the spring. This fairly simple but effective and reliable design mechanism lends itself fairly well to mass production at reduced costs, in particular because the majority of parts can be molded from plastic.

SUMMARY DESCRIPTION OF THE DRAWINGS

The invention will be better understood from the study of embodiments taken without any limitation being implied and illustrated in the appended figures in which: - Figures 1a and 1b are views in longitudinal section respectively from the side and from the front of a first variant of the first embodiment of the hand-held dispenser according to the invention,

- Figures 2a, 2b and 2c are views similar to Figures 1 during different stages of use of the first distributor, - Figures 3a and 3b illustrate views in longitudinal section from the side and front respectively of a second variant of the first embodiment of the hand-held dispenser according to the invention,

- Figures 4a and 4b are views similar to Figures 3 showing the method of loading the wax, - Figures 5a and 5b illustrate views in longitudinal section from the side and front respectively of another embodiment of the dispenser according to Figures 3,

FIGS. 6a, 6b and 6d are side longitudinal section views of a second embodiment of the hand-held dispenser according to the invention, view 6c being a front section view of the dispenser according to FIG. 6b, and

FIG. 7 illustrates in longitudinal section a variant of cartridge adaptable to the dispenser of FIG. 6.

BEST WAY TO IMPLEMENT THE INVENTION

In FIGS. 1a and 1b, a first variant of a depilatory wax distributor is illustrated, the means for heating the melting of the wax are based on a first embodiment corresponding to a mobile heating grid through the tank.

This dispenser comprises an external housing 10 for gripping by hand, in this case substantially parallelepiped. In the first upper half of this housing is housed a wax reservoir 12 also parallelepipedal 5 closed in its lower part by a bottom and closed at its upper outlet by a transfer and application roller 20. This reservoir is preferably made of heat conductive metallic material, for example aluminum.

The roller 20 is in the form of a cylindrical plastic sleeve mounted on a metal core. The characteristics of the plastic of the sleeve are chosen as a function of those of the wax, in particular its wettability, in order to entrain this wax in the form of a strip and deposit it on the application surface, in this case the skin of the user. The metal core provides heat transfer by conduction to maintain the strip of wax transferred in a pasty state to the application surface. As illustrated, this roller 20 is mounted between the two ends of the branches of a U-shaped cradle 22 articulated in rotation at its central crosspiece. This roller can therefore be retracted upwards by a rotation of the cradle to release the outlet surface of the reservoir 12. In the closed position, the roller and the cradle are held by two locking snaps 24 arranged in the extension from each end of the axis of rotation of the roller.

A maintenance heating resistor 30 is placed against one of the widest longitudinal walls of the reservoir 12, the other opposite wall being placed against an internal face of the housings 10. This heating element 30 maintains the liquid state wax 5 contained in the reservoir 12 once it has melted.

More particularly according to the invention, the melting of the wax contained in the reservoir, whether in the form of granules as illustrated in FIGS. 1 or in the form of a bar or solid block of wax of dimensions corresponding to those internal of the reservoir, is ensured by a special heating grid 32 held in sound middle by the upper end of a push rod 40 so as to be movable from the bottom of the tank towards the outlet, then back.

To this end, this rod 40 passes through a cylindrical sleeve 11 formed in the center of the bottom of the reservoir 12. In addition to a guiding function, this sleeve also provides a sealing function between the rod and the reservoir facing the molten wax. Furthermore, the upper part of the rod 40, namely that caused to pass through the sleeve during the movement of the grid in the tank, is electrically conductive: either that it is coated with a metallic layer, or that it consists of a full metal rod; the lower part being made of an insulating material such as plastic. Then, the sleeve 11 comprises a seal 13 also serving as an electrical supply electrode for the heating grid 32 through this upper conductive part of the rod 40, the return of the current being effected by the metal of the reservoir 12.

The transverse heating grid 32 can be produced in the form of a weaving with large meshes of resistive electrical wires, or even a molded metal plate with a network of through cells. The dimensions of this grid correspond to those of the internal section of the tank so as to obtain permanent friction with the walls without jamming. The material and / or the thickness of this grid are established so that they are relatively rigid in their sides, that is to say that they do not bend too much at their peripheries when pushed into their environments.

The means of displacement of the rod 40, therefore of the heating grid 32 within the tank 12, are based on a mechanism transforming a rotational drive movement from a motor into an alternative translational movement. As illustrated, this mechanism first includes a transverse slide 42 mounted at the lower end of the rod 40, this slide having a groove or an oblong transverse opening. In this groove is engaged a stud 43 secured to the periphery of a wheel 44 whose central axis is held, free to rotate, at the end of a lower extension for supporting the reservoir 12. This stud 43 is therefore eccentric relative to the axis of rotation of the wheel. A spiral spring 45 coaxial with the wheel is fixed on the one hand to a gear 46 mounted free in rotation on the axis of the wheel and on the other hand, against the internal face of a rear flange of the wheel 44, this flange forming a protective housing for this spiral spring. This gear 46 is engaged with a pinion secured to an axis passing through the housing 10 and ending with a button 47 or other crank. This button for manually applying a rotation to the gear 46 only in one direction called "arming", the other direction being blocked by a pawl acting on the button, the pinion or the gear. The wheel 44 is itself retained by a second pawl to prevent it from turning unexpectedly when the spiral spring 45 is somewhat tensioned.

A switch 49 is arranged near the lower end of the wheel 44 so as to be tilted by the transverse slide 42 when it is in its bottom dead center as illustrated in FIG. 1.

The mode of use of this dispenser as described above will now be detailed with reference to Figures 2.

The pair of Figures 2a illustrates how the roller 20 can be retracted out of the outlet of the reservoir 12 by rotation up its cradle 22. It is then possible to load the reservoir with wax 5 into bread or granules. After having folded down the roller and having locked it in place by action on the holding buttons 24, the user acts on the button or the external handle 47 to tension the internal spiral spring 45. The user then acts on the second pawl to release the wheel 44 which, under the influence of the spring 45, begins to rotate, thereby driving the longitudinal central rod 40 upwards pushing the grid 32 against the wax. The lower switch 49 toggles then triggering the grid power supply.

As illustrated in the pair of FIGS. 2b, the grid supplied with a high electrical power heats quickly, but in a homogeneous manner, the whole slice of the wax bread or the granules in contact. This slice of wax melts and then quickly becomes liquid, which allows it to pass through the mesh of the grid to flow towards the bottom of the tank, the grid pushed by its rod coming immediately into contact with the next slice which is still solid. . This next section also melts very quickly to also flow through the grid. This process is developing continuously, and we see that the grid progresses at a substantially constant speed on both sides of the tank. Above all, thanks to this progressive advancement of the grid, the temperature thereof is automatically regulated to a value greater than a few degrees than that of the melting of the wax. As can easily be understood, the speed of progression of this grid in the wax bar essentially depends on the speed of melting of the successive slices, itself dependent on the electric power applied to the grid. However, the temperature of the grid regulating itself automatically, we can allow ourselves to apply a strong power to it precisely to accelerate this fusion, thus to decrease the waiting time.

The pair of FIGS. 2c illustrates how the continued rotation of the wheel 44 has brought the grid back to the bottom by passing through the wax, the fusion of which it confirms. When the transverse slide 42 returns to its bottom dead center, it switches back the switch 49 which stops the electrical supply to the movable grid and which switches on that for the additional heating resistor 30 for the sole maintenance of the wax in the state melted in the tank. By then orienting the dispenser downwards, the force of gravity brings the molten wax against the roller which causes a sheet at its periphery, the thickness of this sheet being calibrated by the thickness of the gap present between the roller and the corresponding edge of the housing, these two elements having a calender effect.

The invention is not strictly limited to this embodiment as described but encompasses many variations. In particular, a person skilled in the art can easily modify the advance and backward mechanism of the grid. If desired, it can replace the spring motor with an electric motor. It can also replace the wheel 44 with its stud 43 by a crankshaft and / or replace the lower part of the rod 40 and the transverse slide 42 by a connecting rod articulated at its two ends.

FIGS. 3 and 4 illustrate a second variant of a depilatory wax dispenser, the means for heating the melting of the wax are based on a first embodiment corresponding to a grid movable through the reservoir.

This second variant is characterized in that the heating grid 50 is arranged in a longitudinal plane of the housing 10, and in that it is formed of parallel bars side by side made of a material which deforms itself under the effect heat. In particular, each bar is a bimetallic strip made up of two different metal blades joined flat and each having a substantially different coefficient of expansion so as to bend during temperature variations. As best seen in Figures 3b and 4b, this longitudinal grid is preferably produced by cutting from a bimetal plate to form a single sinusoidal strip of elongated rectangular shape, each bar being connected in series to the next bar by a connection located alternately with upper and lower lateral edge of the grid. These connections are fixed on the one hand on a lower support 52 having the shape of a transverse bar, and on the other hand on the central crosspiece of an upper support 54 in the form of U, the lateral branches 56 receiving the two ends of electrical connection 57 of this grid. In addition, this bimetallic grid 50 has, seen from the side, an initial curvature in an arc.

Then, the dispenser comprises a gripping box 10 whose external shape is as pleasant and aesthetic as possible and containing an internal reservoir 16 whose longitudinal section, as seen from the side in FIGS. 3a and 4a, is in the form of a lens, i.e. defined by two arcs of circles symmetrical with respect to the median plane of the distributor, these arcs of circles being substantially equal to the arc of a circle defining the initial curvature of the bimetallic strip 50.

As illustrated, the upper U-shaped support 54 of grid 50 is articulated in rotation at the end of each of its lateral branches 56, and this at the level of the axis of rotation 55 of the roller 20 closing the outlet of the reservoir 16. By against, the second rear support 52 of the bimetallic grid 50 is movable by sliding in a bottom groove 14 of the reservoir 16. As better visible in FIGS. 4a and 4b, the roller 20 is mounted at the end of a cradle 23 retraction in translation, that is to say that this roller is held on either side by two plates whose lower hook edge slides in grooves formed in the lateral internal face of the reservoir 16, and whose upper edges are folded in a U to bypass the lateral branches of the upper support 54 of the bimetallic strip 50.

Usefully, one of the bars of the grid is partially magnetized or carries a small magnet and the housing includes two flexible blade switches in correspondence in the front and rear longitudinal faces. These switches make it possible to detect the position of the bimetallic grid within the tank: either against the longitudinal front face: only the corresponding front switch being flipped; either in the middle of the tank: none of the switches being flipped; either against the other rear longitudinal face: only the other rear switch being flipped.

This dispenser is used as follows.

Initially, and as illustrated in FIGS. 4, the bimetallic grid is located against the rear longitudinal face. The roller 20 is released by pulling on the retraction cradle 23 to impart a translation towards the outside. We can then fill the tank 16 with wax granules. Once the roller has been replaced, the user can turn on the power supply to the bimetallic grid, which begins to heat up. Due to its temperature rise, the bimetallic grid 50 begins to stiffen, therefore to press against the granules 5. The bimetallic grid continues to rise in temperature until reaching that of melting of the wax. The wax granules in contact begin to melt, and, once liquid, pass through this grid. This, continuing to deform under the influence of its high temperature, immediately comes into contact with the following still solid granules which also melt quickly. As the granules melt, the deformation of the bimetallic grid can continue, making it thus continuously cross the entire tank until it comes to press against the opposite longitudinal front face, the corresponding switch then toggling. During this deformation, the free lower support 52 has advanced and then retreated within the groove 14. The supply of the heating grid is then stopped to start supplying additional heating means for maintaining the wax. in the molten state, for example self-regulating PTC resistive elements (that is to say with a positive temperature coefficient).

If desired, provision may be made for the width of the bars of the bimetallic longitudinal grid 50 to be thinner in the middle of the grid than at its two upper and lower ends. This grid being in this median level more resistive, it delivers there more calorific power, which accelerates its progression thus compensating for the fact that the volume of wax is greater at this level. The fact remains that this grid is homogeneous in the portions of successive surfaces defined by its width and by the units of length.

The wax being melted, it suffices to tilt the dispenser downward to bring the wax by gravitation against the roller, this wax being distributed in a sheet of thickness controlled by the calender formed by the roller and its adjacent housing edge.

FIG. 5 illustrates a second embodiment of a dispenser comprising a bimetallic grid 60 in which the longitudinal section seen from the side of the reservoir 18 containing the wax 5 is substantially triangular in its second lower half close to the bottom. Then, the lower support 62 of the grid 60, receiving the two connection electrodes of this bimetallic grid, the bars of which are also connected in series, is rigidly fixed to the bottom of the tank. By cons, the opposite upper support 64 is freely movable in translation to pass from the front side to the rear side of the dispenser during the deformation of this grid under the effect of heat. This arrangement makes it possible to substantially increase the volume of the reservoir 18 slightly outside of the roller 20 mounted on its cradle 23 for retraction in translation.

Figures 6 and 7 illustrate a dispenser based on a second embodiment of the wax heating means according to the invention in which these heating means reside in a substantially homogeneous manner in the mass of the wax contained in the tank.

More particularly and as best seen in Figures 6 and 7, the wax tank is here in the form of removable cartridges 70,71 of cylindrical shape, rectangular cross section, and possibly circular. According to a first variant illustrated in FIGS. 6b and 6c, the upper nozzle 78 for dispensing the cartridge has a longitudinal section viewed from the triangular side, ending in a long, elongated opening with a spatula allowing the spreading of the wax once melted. According to a second variant illustrated in FIG. 7, the upper outlet of the cartridge is closed by a transfer and application roller 79, the two ends of the axis of rotation of which are held in lateral tabs of the cartridge. In the case of a cartridge of circular section, the dispensing spout can then be conical to end in a circular outlet orifice for depositing fine lines of wax.

The upper part of these cartridges also has a collar 72 for fixing to a dispenser described below. At their other lower end, these cartridges are closed by a piston head 76 of dimensions corresponding to those of their internal section so as to be able to slide therein longitudinally while ensuring a seal opposite the wax. fondue. For example, this piston head 76 may have a rear peripheral flange of friction against the internal wall of the cartridges.

More particularly according to the invention, the heating means here consist of a resistive wire 74 looped in a substantially homogeneous manner throughout the volume of wax granules 5 or throughout the volume of wax bread initially present in this cartridge. This looping can have either a regular arrangement in several superimposed planes or, as illustrated, be apparently random in the manner of a bundle of more or less wide loops. The two ends of this wire are connected to lateral contact electrodes 75 arranged on either side of the cartridge, for example in its lower part. As an alternative, it is possible to consider replacing this looped resistive wire with a very wide mesh metallic foam. Such a foam can be produced, for example, by electrolysis in a bath of metal salts of a commercially available fibrous foam. This resistive foam is then supplied by two vertical longitudinal electrodes arranged on either side of the cartridge.

As illustrated in the lower part of FIG. 6a, the associated dispenser 80 comprises a manual gripping unit whose external shape rather meets aesthetic criteria and whose interior comprises a receptacle 82 longitudinal behind an opening for introducing the cartridge . The internal shape of this receptacle 82 corresponds substantially to that of the external cartridge 70 except for a cylindrical lower extension closed by a base 88. Inside this receptacle is arranged an upper transverse piston 84 and a lower compression spring 86 resting, at the level of the extension against the base 88 and pushing the piston 84 upwards.

A mechanism makes it possible to control the position of the piston 84 inside the receptacle 82 when placed under the pressure of its spring. This mechanism comprises a wire 90 coaxial with the receptacle, connected on the one hand to the piston 84 and crossing on the other hand the base 88 to come and wind around a drum 92 movable in rotation under the effect of a spring internal hairspring 94. A lever of retainer 96 acts like a ratchet, that is to say that its lower short branch bears against the drum while its upper long branch ends in a button emerging from the housing, a push on the button releasing the lower branch out of contact with the drum 92.

The edge of the upper opening for introducing the dispenser has means of attachment complementary to the locking collar 72 of the cartridge 70.

The mode of use of the dispenser described above will now be detailed with reference to Figures 6a to 6d.

The user presents the cartridge 70 in front of the dispenser insertion opening as illustrated in FIG. 6a. When it pushes this cartridge 70 inside the dispenser, the piston head 76, retained by the volume of wax 5 present in the cartridge, comes to press and push the piston 84 downward, which on the one hand compresses the spring 86 and on the other hand authorizes a winding of the lower part of the wire 90 around the drum 92 rotating under the action of its spiral spring 94. This introduction is continued until the flange 72 of the cartridge comes place against the periphery of the dispenser insertion hole in which it is locked, for example following a quarter-turn rotation if the section of the cartridge is circular, or by flexible hooks, if the section is rectangular. In this final position, the electrodes 75 of the cartridge come into contact with corresponding electrodes formed in the internal face of the receptacle. The exhaust lever 96, having authorized rotation of the drum clockwise, retains the latter against rotation in the opposite direction. The dispenser thus ready for use is illustrated in FIGS. 6b and 6c.

By action on a switch not shown, the user then triggers the power supply in the resistive wire 74 for heating and melting the wax. This fusion is all the more rapid as the filament being thin and long, it presents maximum contact surface with the wax for transmission of calories In addition, given that this wire is distributed in a substantially homogeneous manner in the mass of the wax, the heating can be established at a value sufficiently high to melt this wax relatively quickly without risk of burns. A thermal sensor can measure the temperature of the wax and reduce the power supply some time after it has reached the melting temperature, and this at a value just sufficient to maintain this wax in the liquid state.

Then, and as illustrated in FIG. 6d, an action on the button of the exhaust lever 96 makes it possible to let the wire 90 unwind, thus authorizing an upward movement of the piston 84 under the action of its helical spring 86. The molten wax is then pushed towards the dispensing spout 78 or the roller 79 for spreading over the skin of the user. This advance of the piston 84 results in compression of the bundle of loops of flexible resistive wire. If the button of the exhaust lever is released, the wire 90 and the piston 84 are again locked in position, which stops the output of the wax. Pressing the exhaust lever again triggers the spreading of the wax.

In all the examples described of distributors, the heating means are supplied with electric power from a step-down device, for example from 220 V AC to 12 V DC. Preferably, these means also make it possible to adjust the electric power to a predetermined value as a function of the characteristics specific to each of the waxes used. Many other improvements can be made to these dispensers within the scope of the claims.

POSSIBILITIES OF INDUSTRIAL APPLICATION

The invention finds its application in the field of wax hair removal devices and more particularly in that of consumer devices.

Claims

1. Hand-held dispenser of hot-melt material, in particular depilatory wax (5), comprising a housing (10) forming a manual gripping means inside which is a reservoir (12, 16, 18) of solid hot-melt material in granules or in the form of a bread as well as heating means (30) of this hot-melt material, characterized in that all or part of these heating means (74) is arranged in a substantially homogeneous manner throughout the volume of the reservoir or (32.50) in one or more surfaces capable of movably passing through substantially the entire reservoir.

2. Distributor according to claim 1, characterized in that the heating means are in the form of a grid (32.50) formed of resistive heating wires initially arranged against one of the sides of the tank and capable of being move to the other opposite side.

3. Distributor according to claim 2, characterized in that the cross section is constant all along the tank (12), and in that the heating means are a transverse grid (32) with meshes of dimensions equal to or slightly less than those of the section, this grid being moved from the bottom of the tank towards the outlet, then back towards the bottom, by means of displacement of the grid.

4. Distributor according to claim 3, characterized in that the displacement means comprise a rod (40) passing through the bottom of the tank (12) and coupled either by an articulated rod, or by a transverse slide (42) to a crankshaft or to a stud (43) offset from a wheel (44) driven in rotation by a spring (45,46,47) or electric motor.

5. Distributor according to claim 4, characterized in that the rod (40) comprises a first conductive part permanently connecting the grid (32) to an electrical supply contact (13) located at the passage (11) of the rod to across the bottom of the tank, followed by a second insulating part connected to the connecting rod or to the slide (42), the periphery of the grid being in contact with the metal walls of the tank.

6. Distributor according to claim 2, characterized in that the heating means comprise a longitudinal grid consisting of a series of close parallel bimetallic strips arranged side by side between two electrodes extending respectively along two opposite edges of the grid , or a grid (50) consisting of a single sinusoidal bimetallic strip passing alternately from a support (52) along one edge to another support (54) along the opposite edge.

7. Distributor according to claim 6, characterized in that the width of the bimetallic strip (s) is variable in the direction of the length of the grid, this width being identical within each successive section of surface extending from a lateral edge to the other of the grid.

8. Distributor according to one of claims 6 or 7, characterized in that the longitudinal section seen from the side of the reservoir (16) is in the form of a lens, in that the longitudinal bimetallic grid (50) is articulated in rotation around the first lateral support / electrode (54), or around a parallel axis adjacent to the outlet of the reservoir, for example at the axis of the roller, and in that the opposite lateral support / electrode (52) is guided in longitudinal sliding at the bottom (14) of the tank; or vice versa, the first support / electrode being articulated at the bottom of the tank.

9. Distributor according to one of claims 6 or 7, characterized in that the longitudinal section seen from the side of the reservoir (18) becomes triangular at its bottom, and in that the longitudinal bimetallic grid (60) is not fixed at the bottom of the tank by its corresponding support / lateral electrode (62).

10. Distributor according to one of claims 2 to 9, characterized in that the outlet from the reservoir (12, 16, 18) leads to a transfer and application roller (20) mounted on a retractable cradle (22, 23) in rotation or in translation.

11. Distributor according to claim 1, characterized in that the heating means are a resistive electric wire (74) for heating arranged in a package of loops which is substantially homogeneous in the volume (70) of the tank.

12. Distributor according to claim 1, characterized in that the heating means are a loose foam of resistive electric heating material, this foam being supplied by two opposite electrodes.

13. Dispenser according to claim 11 or 12, characterized in that the wire (74) or the foam of the heating means is flexible, and in that the reservoir comprises means (76,84,86) for pushing the wax towards the exit.

14. Distributor according to claim 13, characterized in that the reservoir is a removable cylindrical cartridge (70) one end of which is closed by a sliding piston head (76) and the other end ends in either a spout (78), either by a distribution roller (79), the associated distributor (80) comprising a piston (84) pushed forward in a receptacle (82) of cartridge, and this by a spring (86) under the control of 'a mechanism (90,92,94,96).

15. Distributor according to claim 14, characterized in that the distributor control mechanism (80) comprises a wire (90) wound on a drum (92) driven by an internal spiral spring (94) when the spring of the piston (86) is compressed, as well as a retaining lever (96) of the drum when the wire unwinds being driven by the piston pushed by the spring.