Background The removal and particularly the uprooting of human body hair, such as the depilation of women's legs is typically accomplished with the aid of a depilatory device and/or wax.

Depilatory devices are well documented in the prior art and include a major class of devices directed at removing body hair by trapping, gripping and pulling the same from their roots. While these devices are relatively simple to use, they are generally mechanically complex and thus represent a relative high initial capital outlay for users. Furthermore many of these devices cannot always be relied upon to yield good results, since close tolerances between parts, particularly pincer elements, are relaxed with use. In such cases, while hairs are pulled and tugged by the device, they are not ultimately removed, thus causing unnecessary pain to the user. The traditional wax method is based on applying pre-heated wax to the skin and typically yields good results, and is therefore still favoured by many users.

In one such way of carrying out the wax method, wax is heated in a special receptacle, and a quantity of hot wax is taken therefrom by manually dipping an applicator such as a spatula or spoon into the hot wax. The applicator is then used to spread the wax onto an area of skin in which it is desired to uproot hair. When the wax solidifies it adheres to hairs, and brisk removal of the wax typically ensures that these hairs are uprooted from the skin. However, there are a number of disadvantages to this method: the wax can be too hot and thus may cause skin burns, or may be too cold and thus not adhere to the hair.

Further, the method of application does not generally ensure an even spread of the wax over the skin, except for the more skilled user. Uneven distribution of wax may lead to part of the wax coating on the skin remaining behind when attempting to remove the wax coating. Removal of residual wax patches from the skin can be a painful and time-consuming procedure, and also results in less than perfect results. Also, in order to reuse the wax for a different area on the leg, for example, the wax has to be removed and placed in the heating receptacle, and heated again. As described above, handling of the warm wax requires some skill and may cause burns to the user. An improvement over this method includes the use of wax strips that are preheated in a toaster-type heater and then applied manually onto the desired area of the skin. The wax strips typically comprise a suitably sized rectangular substrate or backing made from a suitable material, the backing being coated with a layer of wax. While the wax in the wax strips is in the form of a substantially constant-thickness layer, this method suffers from a number of disadvantages. For example, if the heated wax strips are not taken form the heater and placed on the desired location on the skin sufficiently quickly, the wax may cool down and may at least partially solidify prior to the strip being properly applied onto the skin. In such a case, some portions of the skin area may be left with hair after the strip is removed, requiring the procedure to be repeated.

It is therefore an aim of the present invention to provide a device and method which overcomes the limitations of prior art wax hair-removal devices and methods, and enables skin hair to be efficiently and safely removed using wax.

It is another aim of the present invention to provide a device for applying heat to cold wax strips positioned on the skin.

It is another aim of the present invention to provide such a device that is simple to use.

It is another aim of the present invention to provide such a device that is relatively simple mechanically and thus economic to produce as well as to maintain.

It is another aim of the present invention to provide such a device that incorporates a heat control system for self-limiting the device to a predetermined maximum temperature, and thus prevent overheating.

The present invention achieves these and other aims by providing a heating device or appliance in the form of an applicator that is selectively mountable and dismountable on a heating base. The applicator comprises a heatable roller rotatably mounted in a grippable housing, and the roller is heated by means of thermal contact with a heater element comprised in the base when the applicator is mounted thereon. When the roller is heated to the appropriate temperature by the heater, the applicator is dismounted from the base and the heated roller is gently rolled over a cold-wax strip previously placed on the skin. The warmed wax adheres to skin hairs, and after briskly removing the cooled strip, the hairs are uprooted from the skin. An even distribution of the applied wax on the skin may be achieved in a relatively easy and straightforward manner by ensuring that the heated roller is passed over the full extent of the strip. The device is relatively simple mechanically, with few moving parts, reducing the per-unit manufacturing and maintenance costs. The device may optionally comprise a temperature safety cut-off system, such that the temperature of the heater does not exceed a predetermined maximum temperature, and thus prevents overheating of the roller, even when left for <BR> <BR> long periods mounted onto the heatmg base. Thus, the device of the present invention enables the strip to be handled and properly positioned on the skin when cold, thereby improving safety for users. Furthermore, it may be ensured that the wax strip reaches the desired temperature on the skin, and that the wax layer thickness is uniformly maintained. The possibility also exists to use the same wax again and again by simply applying the wax strip over different areas of the leg, for example, and applying the heated roller to the strip each time.

Summary of Invention The present invention relates to a device for applying heat to cold-wax strips, comprising:- (a) an applicator portion comprising ;- a roller housing; a roller rotatably mounted in said housing, said roller having an external surface adapted for thermal contact with suitable wax paper, at least a portion of said external surface of said roller being heatable to a temperature at least within a predetermined temperature range; and a suitable opening in said housing adapted to enable at least a first portion of said external surface to protrude from the housing ; and (b) a base portion comprising :- at least one heater element capable of being heated to a temperature at least within said predetermined temperature range; a heat-conducting roller seat in thermal communication with said at least one heater element, said roller seat adapted to receive at least a second portion of said first portion of said external surface when said applicator portion is mounted onto said base portion, said roller seat comprising a thermal contact surface adapted to provide thermal communication between said roller seat and at least said external surface of said roller when said roller is seated in said roller seat; wherein said applicator portion is selectively mountable onto and dismountable from said base portion.

Preferably, said base portion comprises a base housing for housing at least said at least one heater element and said roller seat. The thermal contact surface is typically substantially complementary to said second portion of said first portion of said external surface.

The said external surface of said roller may comprise a substantially cylindrical, convex or concave axial profile radially displaced from a central axis of said roller, such a concave axial profile preferably being substantially complementary to the curvature of a human limb such as a human leg, for example. The external surface of said roller typically comprises an axial dimension between about 3 cm and about 15 cm, and preferably within about 5 cm and about 10 cm, and said axial dimension is more preferably about 6 cm.

The at least one heater element is typically heatable electrically, and is thus preferably adapted to be electrically connected to a suitable external electrical power source, in particular a domestic AC electrical supply.

The roller and the roller seat are preferably each made from the same or different heat-conducting material capable of being heated to a temperature within said predetermined temperature range, typically a metal and/or a metal alloy, and preferably aluminium.

The said first portion of said external surface may comprise between about 20% and about 50%, and preferably comprises about 40%, of said external surface, while the said second portion of said first portion of said external surface comprises between about 70% and about 100%, and preferably comprises about 85%, of said first portion of said external surface. The said temperature range may be typically from about 50°C to about 75°C, preferably from about 55°C to about 70°C, and more preferably from about 60°C to about 65°C.

Optionally, the device further comprises suitable control means for preventing at least said at least one heater element being heated to a temperature exceeding at least said temperature range. The control means is also typically capable of maintaining the temperature of at least said at least one heater element within said temperature range The base portion of the device is advantageously adapted to be placed on a substantially horizontal surface and wherein said thermal contact surface is substantially upwardly facing, while the roller housing is adapted to be held in the hand of a user and may thus comprise a shape suitable to be grasped by a hand or alternatively comprises a suitable handle means integrally or fixedly or releasably attached thereto, said handle means being adapted to be held in the hand of a user.

Preferably, the roller housing and the base housing are each made from a thermally insulating material.

The present invention is also relates to a method for applying heat to wax paper comprising the steps of :- (a) providing suitable wax paper and placing said wax paper on a desired portion of skin comprising hairs; (b) providing a heating device as described herein, in which at least one heater element is capable of being heatable electrically at least by means of an external electrical source ; (c) connecting said at least one heater element comprised in said base portion of said device to a suitable electrical supply such as to enable said heater element to become heated ; (d) ensuring that said applicator portion of said device is mounted onto said base portion, such that said roller is seated on said roller seat; (e) dismounting said applicator portion from said base portion when the said roller has been heated to a temperature within said predetermined temperature range ; (f) passing said applicator portion over said wax paper such that as the said roller is rolled over the said wax paper, heat is transferred from the said roller to the said wax paper; (g) removing said roller from said wax paper ; (h) optionally remounting said applicator portion onto said base portion and returning the applicator portion to the base portion and repeating steps e) to g), or, continuing with step i); (i) removing said wax paper from said portion of skin; (j) optionally remounting said applicator portion onto said base portion and disconnecting said base portion from said electrical supply.

Description of Figures Figure I shows in side elevation cross-sectional view, a preferred embodiment of the present invention in the mounted condition.

Figure 2 shows in side elevation cross-sectional view, a preferred embodiment of the present invention in the dismounted condition.

Figure 3 shows in front elevation cross-sectional view, the applicator of the embodiment shown in Figures I and 2, taken along A-A.

Figure 4 shows in front elevation cross-sectional view an alternative embodiment of the roller of Figure 3.

Figure 5 shows in front elevation cross-sectional view a further alternative embodiment of the roller of Figure 3.

Figure 6 illustrates the device of Figures I to 3 being used to apply heat over a wax strip placed on a leg.

Figure 7 illustrates the applicator portion of Figures 1 and 2 in use over a typical wax strip.

Disclosure of Invention The present invention is defined by the claims, the contents of which are to be read as included within the disclosure of the specification, and will now be described by way of example with reference to the accompanying Figures.

The present invention relates to a device for applying heat to wax paper strips used for the removal of body hair. Referring to Figures 6and 7 in particular, the aforementioned wax paper, also referred to herein as wax strips and designated by the numeral (80), are herein understood to refer to any suitable material backing or substrate (85), carrying at least one layer or coating of suitable wax (95) on at least a portion of one side thereof. The substrate (85) is typically in the form of a sheet or strip and is at least capable of transmitting heat from one face thereof that does not carry wax to the other face comprising the wax layer.

Typically, the said wax paper may be rectangular in shape, usually in strips of about 200mm by 80mm, though they may be in any other shape and/or size as desired. When not in use, the wax strips are also typically folded in two such that the wax layer is sandwiched between outer layers of substrate, or alternatively may simply comprise two layers of substrate with an inner suitable layer of wax. Thus, the strips are easy to handle and store in a mess-free manner, and when needed, the user opens up the sandwich to expose the wax layer on each of the two portions of substrate. The substrate (85) is typically made from a heat conducting material such as metal foil for example, but may also be made from paper since this also conducts heat to a sufficient degree to the wax layer since the thickness of the paper is typically small.

Preferably, the substrate is impervious to wax, and thus wax from the wax coating is prevented from migrating through the substrate (85) and making physical contact with the roller itself. Optionally, and preferably, the substrate (85) comprises border (90) surrounding it, the border (90) not being coated with wax and thus aiding in preventing the roller (30) from accidentally touching the skin. The border (90) may be made from a non-conducting material, but even if made from the same material as the substrate (85), the absence of wax on the reverse side of the border (90) (i. e. that is contact with the skin) in any case reduces the potential for large amounts of heat to be transferred to the skin even if the heated roller is passed over the border (90).

Such cold-wax strips (80) typically need to be heated to a temperature within a predetermined temperature range in order to ensure that the wax is warmed sufficiently to adhere onto hairs. The aforesaid predetermined temperature range is typically from about 50°C to about 75°C, preferably from about 55°C to about 70°C, and more preferably from about 60°C to about 65°C Referring to the Figures, Figures 1,2 and 3 illustrate a preferred embodiment of the present invention. The device, designated by the numeral (10), comprises a applicator portion (20) and a base portion (50), the applicator portion (20) being selectively mountable and dismountable with respect to said base portion (50), as illustrated in Figures 1 and 2, respectively.

The applicator portion (20) comprises a roller housing (25). The roller housing (25) is preferably adapted to be held or gripped manually by a user, preferably using one hand. By being adapted to be held or gripped manually is meant that the housing (25) comprises a suitable shape such that it may be grasped by a hand of a user, and/or, that the housing (25) comprises a suitable handle means integrally or fixedly or releasably attached thereto, said handle means being adapted to be held in the hand of a user. The housing (25), or said handle means, may thus take any convenient grippale form, e. g., such as a cylindrical handle or the like, though in the preferred embodiment the housing (25), or said handle means, respectively, is shaped to be substantially complementary to the arch formed between the thumb and index finger such as to enable the housing (25), or said handle means, respectively, to be gripped therebetween, as illustrated in Figures 3 and 6.

The applicator portion (20) further comprises a roller (30) rotatably mounted to said housing (20), the roller (30) being substantially axisymmetric and freely turnable about its longitudinal axis (100), and comprising a shaft (110) centered thereon. The shaft (110) is accommodated in suitable bushes (122), (124) at each end thereof suitably mounted in said roller housing (25), as shown, for example, in Figure 3. In the preferred embodiment, the roller (30) is preferably oriented in the housing (25) such that the central axis (100) is substantially parallel to the chord of the arch formed between the thumb and index finger when gripping the housing (25) therebetween, as illustrated in Figure 6.

The roller (30) comprises an external surface (35) that is adapted for thermal contact with suitable wax paper (80), i. e., for transferring heat thereto, and the said external surface (35) is thus typically smooth and capable of conducting heat. At least said external surface (35) of said roller (30), and preferably the roller (30) itself, is capable of being heated directly or indirectly by an external heating source, in particular the heater element (60) hereinafter described, to a temperature at least within said predetermined temperature range. Further, and in the preferred embodiment, the external surface (35) of said roller (30), and preferably the body of the roller (30) itself, preferably comprises an optimal heat capacity, sufficiently high such as to retain as much heat as possible while the applicator portion (20) is dismounted from the base portion (50) and transported to a skin site, but low enough such as to enable at least the external surface (35), and particularly the body of the roller (30), to be heated rapidly while on the base (50), and to rapidly transfer as much heat as possible to a wax strip when in contact therewith.

Thus, in the preferred embodiment, at least the said external surface (35), and preferably also the roller (30), is made from a heat-conducting material, such as for example a metal and/or metal alloy including aluminium, said material capable of being heated to a temperature within said predetermined temperature range.

In the preferred embodiment, and as illustrated in Figure 3, the external surface (35) of said roller (30) is substantially cylindrical. Alternatively, the external surface (35) of said roller (30) may comprise a substantially convex axial profile (35a) radially displaced from a central axis (100) of said roller (30), as illustrated in Figure 4. Such a convexly profiled roller is particularly useful for assisting a user in focusing the application pressure of the roller (30) towards any particular region of a wax strip. Alternatively, the external surface (35) of said roller (30) may comprise a substantially concave axial profile (35b) radially displaced from a central axis (100) of said roller (30), as illustrated in Figure 5. Optionally, said concave axial profile is substantially complementary to the curvature of a human limb-in particular, of a leg-in a direction perpendicular to the extension of the limb.

The external surface (35) of said roller comprises an axial length typically in the range of about 3 cm to about 15 cm, and preferably within about 5 cm and about 10 cm, and more preferably comprises an axial length of about 6 cm, though this length may be below 3 cm or above 15 cm. The external surface (35) of said roller typically comprises a radius of about 1 cm to about 2 cm for the preferred embodiment, though this radius may be below 0.1 cm or above 2 cm. For the embodiments shown in Figures 4 and 5, the radius of the said external surface (35) may vary from about 0.5 cm to about 2.5 cm, for example, though this radius may be below 0.5 cm or above 2.5 cm.

The said applicator portion (20) further comprises a suitable window or opening (40) substantially parallel to said axis (100) and adapted to enable at least a first portion (42) of said external surface (35) to protrude from the housing (25). The said first portion (42) of said external surface (35) comprises between about 20% and about 50%, and preferably comprises about 40%, of said external surface (35). The said first portion (42) is typically defined in a circumferential direction, i. e., the said first portion (42) comprises an area of said external surface (35) extending substantially the full length thereof axially, and circumferentially along the said external surface (35) through an appropriate arc, though in other embodiments the said first portion may only extend axially along part of the full axial length of the said external surface (35).

The said base portion (50) preferably comprises a base housing (55), and comprises at least one heater element (60) suitably mounted therein. The said at least one heater element (60) is a heat source capable of providing heat and is thus heated by suitable means to a temperature at least within said predetermined temperature range, and preferably to a temperature higher than the highest temperature in said predetermined temperature range. Preferably said at least one heater element (60) is electrically heatable and thus typically comprises one or more electrical heaters. The said at least one heater element (60) is thus adapted to be electrically connected to a suitable electrical power source, for example an external electrical power source such as a domestic AC electrical supply, via a power line such as a suitable cable for example (65).

Such a power line may be conveniently stored in a chamber (62) within the base (50) via an opening (64) when not in use. Optionally additionally or alternatively, the heater element (60) may be powered by means of an internal or external battery and/or rechargeable accumulator, for example.

The base portion (50) further comprises a heat-conducting roller seat (70) in thermal communication with said at least one heater element (60). The said roller seat (70) is adapted to receive at least a second portion (44) of said first portion (42) of said external surface (35) when said applicator portion (20) is mounted onto said base portion (50) as illustrated in Figures I and 2. The said roller seat (70) comprises a thermal contact surface (72) adapted to provide thermal communication between said roller seat (70) and at least said external surface (35), and preferably also the body of the roller (30), when said roller (30) is seated in said roller seat (70). Thus, the said thermal contact surface (72) is typically substantially complementary to said second portion (44) of said first portion (42) of said external surface (35).

Typically, the said second portion (44) of said first portion (42) of said external surface (35) comprises between about 70% and about 100%, and preferably comprises about 85%, of said first portion (42) of said external surface (35).

The said second portion (44) is typically defined in a circumferential direction, i. e., the said second portion (44) comprises a proportion of the area of the first portion (42) of the said external surface (35) extending substantially the full length thereof axially, and circumferentially along the said external surface (35) through an appropriate arc, which may be smaller than the corresponding arc defined by the said first portion (42), as illustrated in Figures 1 and 2. In other embodiments, though, the said second portion of said first portion may only extend axially along part of the full axial length of the said external surface (35), or along part of the full axial length of the said first portion (42).

Further, and in the preferred embodiment, the thermal contact surface (72) of said roller seat (70), and preferably the body of the roller seat (70) itself, preferably comprises an optimal heat capacity, sufficiently low such as to enable at least the thermal contact surface (72), and particularly the body of the roller seat (70), to be heated rapidly by the heater element (60) and to rapidly transfer as much heat as possible to the roller (30) while the applicator portion (20) is mounted on the base (50).

Thus, in the preferred embodiment, at least the thermal contact surface (72) of said roller seat (70), and preferably also the body of the roller seat (70), is made from a heat-conducting material, such as for example a metal and/or metal alloy including aluminium, said material capable of being heated to a temperature within said predetermined temperature range.

Optionally, said base portion (50) is adapted to be enabled to be placed or rested on a substantially horizontal surface (200), such as a table for example, the said thermal contact surface (72) being substantially upwardly facing.

Advantageously, the base housing (55) comprises friction enhancing contact points (58) and/or suction pads on the underside thereof to substantially prevent, or at least reduce the possibility of, sliding over said surface (200).

Optionally, said device (10) further comprises control means (not shown) for preventing at least said at least one heater element (60) from being heated to a temperature exceeding said temperature range, or any other desired temperature range. Further optionally, the said control means is also capable of maintaining the temperature of at least said at least one heater element (60) within said predetermined or other desired temperature range. In the preferred embodiment, the said control means is typically electrically connected between the said heater element (60) and the power supply and comprises a suitable temperature sensor capable of sensing the temperature of the heater element (60) and/or the roller seat (70). When the sensed temperature exceeds a predetermined maximum value, typically the maximum temperature of the said predetermined temperature range, the electrical supply to the heater element (60) is turned off by the said control means. When the sensed temperature reaches a value below a predetermined minimum temperature, typically the minimum temperature of the said predetermined temperature range, the electrical supply to the heater element (60) is turned on by the said control means. Control means capable of performing such functions are well known in the art and do not require to be described further herein.

Optionally, and preferably, said base portion (50) comprises an indicator light (not shown) for advising when the heater element is in heating mode and when it is disconnected from the electrical supply. Similarly, the applicator portion (20) may advantageously comprise a suitable temperature sensor, for sensing the temperature of the external surface, operatively connected to an indicator light for advising when the temperature of the roller (30), or at least the said external surface (35), is within the said predetermined temperature range and when the temperature has fallen to below the same. The said roller housing (25) and the said base housing (55) are each typically made from a robust and thermally insulating material, capable of thermally insulating the user from the heat of the roller (30) and heater element (60)/ roller seat (70), respectively. Advantageously, the roller housing (25) and the base housing (55) are made from a suitable heat-resistant plastic material, for example, including ABS, Polycarbonate (PC) and Polypropylene (PP), for example, said material preferably capable of being injection-molded.

The present invention also relates to a method for applying heat to wax paper comprising the steps of :- a) providing suitable wax paper and placing said wax paper on a desired portion of skin comprising hairs; b) providing a device (10) as described herein, for example ; c) connecting said base portion of said device to a suitable electrical supply such as to enable said heater element to become heated, ensuring that said applicator portion of said device is mounted onto said base portion; d) dismounting said applicator portion from said base portion when the said roller has been heated to a temperature within said predetermined temperature range ; e) passing said applicator portion over said wax paper such that as the said roller is rolled over the said wax paper, heat is transferred from the said roller to the said wax paper ; f) removing said roller from said wax paper; g) optionally remounting said applicator portion onto said base portion and repeating steps d) to f), or, continuing with step h); h) removing said wax paper from said portion of skin ; i) optionally remounting said applicator portion onto said base portion and disconnecting said base portion from said electrical supply.

Thus, referring to Figures 6 and 7, the device (10) may be used as follows. The heater element (60) is connected to a suitable electrical power supply via said cable (65) and heated to within the said predetermined temperature range while the applicator portion (20) is mounted onto the base portion (50). The heater element (60) heats the roller seat (70), which in turn heats at least a portion (i. e., at least the said second portion of the said first portion) of the external surface (35) and preferably also the roller (30) by means of thermal communication via said thermal contact surface (72). This usually results in the whole roller surface (35) and the roller (30) being heated since they are made preferably from heat conducting materials. When the temperature of at least the said external surface (35) is within said predetermined temperature range, the applicator portion (20) may be grasped by a user via said roller housing (25), or said handle means, and dismounted from the base portion (50). A suitable cold wax strip (80) is placed on a desired area of skin (99), such as on the leg, ensuring that wax layer (95) is on the inside facing towards and in contact with the skin area (99), and that the exposed backing or substrate (85) is on the outer side of the cold-wax strip (80). The applicator portion (20) is then passed (S) over the outer side of the cold-wax strip (80), gently rolling (R) the said roller (30) about its axis (100) over the exposed substrate (85) of the wax strip (80), and taking care not to pass the roller beyond the margin or border (90) on the wax paper (80). The applicator portion (20) may be returned and remounted onto the base portion (50) for reheating, and subsequently reapplied to the wax strips, as many times as desired by the user to ensure that the wax has warmed sufficiently and adhered onto the hairs on the skin below the wax strip (80). Typically, though, one application of the applicator portion (20) over the wax strip (80) is sufficient. The wax strip (80) may then be removed briskly from the skin, thereby uprooting hairs adhered to the wax layer (99) of the strip (80).

While in the foregoing description describes in detail only a few specific embodiments of the invention, it will be understood by those skilled in the art that the invention is not limited thereto and that other variations in form and details may be possible without departing from the scope and spirit of the invention herein disclosed.