Abstract:
The invention is directed to an epilation appliance and a method for using the appliance, in particular for epilation of the human skin, with a hand-holdable housing which accommodates a motor for driving a clamping device ( 14 ), particularly a rotary clamping device, which is provided in the appliance and equipped with clamping elements ( 16 ) to grip and pluck the hairs, and with a component for reducing the sense of pain during the extraction of hairs, the component including at least one electrode. With the component an electric spark ( 76 ) is producible on the skin prior to the extraction of the hairs, the spark ( 76 ) provoking an additional pain corresponding in its pain characteristic to the pain of epilation, but preferably having a lower pain intensity.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an epilation appliance and to a method for using said appliance, in particular for epilation of the human skin. The appliance is comprised essentially of a hand-holdable housing which accommodates a motor for driving a clamping device, particularly a rotary clamping device, which is provided in the appliance and equipped with clamping elements to grip and pluck the hairs, and with a means for reducing the sense of pain during the extraction of hairs, said means comprising at least one electrode. 
     An appliance of this type is known from DE 44 08 809 C1, the disclosure content of which shall be deemed to be incorporated in the present application by express reference. Said appliance has in particular two electrodes which, in order to extract the hairs, can be brought into contact with the skin at the same time as the clamping device. A generator of stimulating current, in particular a pulse generator or the like, is assigned to the appliance, and the generator&#39;s outputs are connected to the electrodes. 
     A general problem facing epilation appliances is to increase their effectiveness during epilation on the one hand and to reduce the user&#39;s sense of pain during the removal of the hairs on the other hand. To this end, the above mentioned appliance uses nerve stimulation produced by the action of a stimulating current, particularly pulses of current, on the skin in order, by irritation or stimulation of the underlying nerve structures, to reduce or even eliminate the pain while the appliance is being used for epilation. During use of the above described appliance the electrodes and the clamping device are jointly in contact with the skin, the treatment of the skin involving the application of pulses of current emitted via the electrodes by means of a pulse generator or the like. These pulses of current ensure that the body&#39;s own pain inhibiting systems existing in the human organism are activated electrically, thus masking or blocking the transmission of those pulses of pain produced by extraction of the hairs. The intensity of the stimulating current can be set individually so that in the area between the electrodes the user feels a slight itching, tingling or the like on the skin but without the triggering of any muscle contractions. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to further develop an epilation appliance and a method, particularly for epilation of the human skin, to the extent that the sense of pain during use of the appliance is further reduced by further masking of the pain of epilation, for example, and that the point of epilation on the skin can always be viewed by the user and is not obstructed by the appliance itself. Furthermore, it is desirable for the intensity of the superposed or masking pain to be uniform and independent of the angle of engagement of the appliance relative to the skin surface. 
     According to the present invention this object is accomplished in that with an epilation appliance of the type referred to in the foregoing it is possible to produce an electric spark on the skin prior to the extraction of the hairs using the means for reducing the sense of pain. With an epilator of this type, advantageously nerve stimulation is positively influenced by the spark discharge to such a degree as to achieve a notable reduction of the sense of pain during epilation, as practical tests have shown. The epilation process is experienced by the user as more agreeable than with an appliance operating without the proposed spark discharge. Furthermore, the current point of epilation on the skin can be viewed at any time by the user and the intensity of masking of the pain of epilation is individually adjustable by the user so that an agreeable intensity can be set for the individual&#39;s sense of pain. What is more, the pain masking intensity does not depend on the angle at which the appliance is held against the skin but is guaranteed advantageously at every moment of the epilation because the spark discharge depends on the distance required in each case between the electrode and the skin surface requiring epilation. 
     In an advantageous embodiment of the present invention the means for reducing the sense of pain is equipped with a voltage source, in particular for electric voltages greater than 0.8 KV, and at least one electrode connectable to said voltage source, said electrode being at least temporarily a distance away from the skin, thus enabling the spark to be produced in the air gap between the skin and the electrode. 
     According to a particularly advantageous further aspect of the present invention the epilation appliance is equipped with a means comprising at least two electrodes and a high-voltage source, in particular for voltages of between 0.8 and 3.0 KV. In this arrangement the at least two electrodes are connectable to the high-voltage source, and at least a first electrode is movable at least temporarily into contact with the skin and at least a second electrode is at least temporarily a distance away from the skin, thus enabling the spark to be produced in the air gap between the skin requiring epilation and the first and/or second electrode. Since the electrodes are connectable to a high-voltage source, spark emission is advantageously performed independently of skin resistance and hence without touching the skin. A preferred voltage range lies between 1.0 and 2.5 KV. Furthermore, since the at least one first electrode can be moved into contact with the skin at least temporarily and the at least one second electrode is a distance away from the skin at least temporarily, several variation options result advantageously for the design of the first and second electrodes: 
     Thus it is possible, for example, for the at least one first electrode to be designed so that it is continuously in contact with the skin requiring epilation and for the at least one second electrode to be moved discontinuously in contact with the skin in such a way, for example, that the second electrode is movable towards and away from the skin. Spark discharge then takes place in the air gap between the second electrode and the skin. 
     Advantageously, in a second embodiment both the first and the second electrode are movably fitted to the epilator so that the two electrodes are moved either simultaneously or with a time lag towards and away from the skin. The time lag is such that, for example, the first electrode is in contact with the surface of the skin while at the same time the second electrode is a distance away from the skin so that a spark discharge takes place in the air gap between the second electrode and the skin. 
     A third alternative embodiment is comprised, for example, of two electrodes in a quasi fixed arrangement on the epilation appliance. In this embodiment the at least one first electrode is in quasi continuous contact with the skin and the at least one second electrode is continuously arranged a predetermined distance from the skin; in this arrangement, however, the at least one second electrode is triggered electronically so that at the right moment prior to epilation of the skin an electric spark can be produced between the second electrode and the skin. 
     According to an advantageous aspect of the present invention at least one electrode is connected to the clamping device and constructed in particular as a clamping element, brush, contact ring, contact disk or the like. Such an electrode can be used advantageously to produce a discontinuous contact with the skin because the electrode approaches and recedes from the skin when the clamping device is rotated. One electrode in continuous contact with the skin is constructed advantageously as a contact shoe, contact bridge, sliding contact, suction contact, contact pad or contact plate or the like and arranged on the outside of the appliance housing. 
     Advantageously, a separate contact pin for connecting to the high-voltage source and extending essentially parallel to the axis of rotation of the clamping device constructed as a rotary cylinder is allocated to the at least one electrode, in particular a clamping element. A component required for the mechanical actuation of the epilator, namely the contact pin for driving the clamping elements, can thus also be used as electrical component for electrically connecting the clamping elements to the voltage source. 
     In a particular further development of the epilation appliance, two or more electrodes, in particular clamping elements, are arranged side by side on the rotary cylinder and in a row parallel to the axis of rotation. One or several rows of clamping elements constructed as electrodes can thus be provided advantageously on a cylinder, and all the clamping elements of one row can be in contact simultaneously with the skin requiring epilation. Alternatively, the clamping elements of one row are arranged at an angular offset to the clamping elements of a neighboring row so that at a certain moment only two clamping elements of one row come into contact with the skin and the clamping elements of the following row reach a contact point on the skin that is offset relative to the preceding row. 
     In a particular embodiment of the present invention, the contact pin is adapted to make contact at the one end with an electrode, in particular a clamping element, and/or at the other end with a sliding ring or the like, said sliding ring or the like being connectable in turn to the high-voltage source. This results advantageously in a simple, low-cost implementation of the electrical connection between a high-voltage source, provided in particular inside the appliance housing, and the clamping elements, constructed as electrodes, without the use of any additional components that are not already required for the mechanical actuation of the clamping elements. 
     In a further embodiment of the present invention, the rotary cylinder has an electrically conductive shaft that is carried in bushings in the appliance housing, and/or said at least one electrode, particularly a clamping element, is joinable to the shaft by an electrically conductive connection on the one hand and/or at least one bushing is joinable to the high-voltage source by an electrically conductive connection on the other hand. Economy of construction is achieved advantageously by using the mechanically essential parts as electrically conductive parts. 
     In a further particular embodiment of the present invention, provision is made for at least one group of electrodes, particularly clamping elements, of equal electric potential, but preferably provision is made for at least two groups of clamping elements of unequal electric potential; in the latter case provision is made between the two groups of electrodes for an electrically neutral area, particularly an insulator, so that no arcing occurs between the two groups of electrodes of unequal electric potential. The thickness of the insulator, that is, the distance between the two groups of electrodes is selected depending on the maximum producible voltage value. It is thus possible by simple means for the two groups of electrodes of unequal electric potential to be arranged inside the clamping device, in particular the rotary cylinder, required for epilation without having to provide additional components on the appliance. 
     Advantageously, the at least two groups of electrodes, in particular clamping elements, of unequal potential contain preferably the same number of clamping elements, each group occupying an essentially annular area on the shell face of the clamping cylinder, and said shell face preferably having one area of positive potential and one area of negative potential when a direct voltage is applied. Reliable contacting of the two unequal potentials on the skin requiring epilation is thereby ensured by simple means. 
     According to a particular embodiment of the present invention, the electrodes, in particular the clamping elements, of the first group with negative potential are in spaced relation to each other in the circumferential direction of the clamping cylinder in such a way that one clamping element is in contact with the skin practically all the time, thus enabling advantageously a continuous connection between this potential and the skin. By contrast the electrodes, in particular the clamping elements of the second group with positive potential are spaced further apart in the circumferential direction of the clamping cylinder than the electrodes of the first group so that the distance between two consecutive clamping elements in the cylinder&#39;s direction of rotation is such that temporarily none of the clamping elements of the second group is in contact with the skin. In spacing the clamping elements of the second group in this manner an advantageous discontinuous contacting of the electrodes with the skin is proposed. 
     Since the clamping elements are provided preferably as strip-shaped blades diametrically arranged in a rotary cylinder, neighboring clamping elements can be set in an angularly offset relation to each other so that when one clamping element recedes from the skin the neighboring follow-up element is just coming into contact with the skin. This ensures in simple manner that one clamping element is in engagement with the skin at all times. In this arrangement it is well possible for the clamping elements of the second group to be distributed on the rotary cylinder in the same way as the clamping elements of the first group. Considering, however, that only every second clamping element of the second group, for example, is constructed as an electrode, no clamping element of the second group constructed as an electrode is in contact with the skin after the first clamping element is disengaged from the skin and before the third clamping element engages the skin. A construction of the clamping elements as electrodes which enables random options of variation as regards contacting between the electrodes and the skin is thus proposed in simple manner. 
     In a further aspect of the present invention provision is made for a control device, in particular an electric or electronic circuit, which controls the voltage supply, particularly to the second electrode, should the first and the second electrode be in permanent contact with the skin. Furthermore, the control device reduces the electric current after the second electrode touches the skin. On the one hand a control system permitting a first and a second electrode is thus proposed, wherein both electrodes are in a quasi fixed arrangement on the epilator, i.e., the first electrodes are constructed as clamping elements on a rotary cylinder, their relative distance in the circumferential direction being selected small enough for one clamping element to be in contact with the skin at all times during use. This control device also ensures that only a very small, no longer notable current flows from the electrode into the skin as soon as the positive and the negative pole are in contact with the skin simultaneously. 
     A particularly advantageous embodiment of the present invention representing an independent solution of the object of the invention proposes a method for the epilation of the human skin, said method involving in particular a step for reducing the sense of pain during the extraction of the hairs by means of an electrically operable epilation appliance with at least one electrode. According to the invention an electric spark is produced on the skin directly prior to the extraction of hairs. The invention uses nerve stimulation produced by the action of a stimulating current, in particular spark discharge, on the skin. This irritation or stimulation of the nerve structures results advantageously in an alleviation of the pain by masking of the pain of epilation while the appliance is being used for epilation. 
     In an advantageous further configuration of the method, at least one electrode is connected to a voltage source, in particular for electric voltages greater than 0.8 KV, and the electrode is positioned at least temporarily a distance from the skin so that the spark is produced in the air gap between the skin and the electrode. 
     In a particular embodiment of the method of the present invention, at least two electrodes are connected to a high-voltage source, in particular for voltages of between 0.8 and 3.0 KV but preferably between 1.0 and 2.5 KV. Preferably at least one first electrode is brought, at least temporarily, into contact with the skin requiring epilation and/or at least one second electrode is positioned, at least temporarily, a distance from the skin so that a spark is produced in the air gap between the skin and the first and/or second electrode. Such an implementation of the method results advantageously in itching or tingling on the skin which masks the pain of epilation notably. Particularly suitably, the spark discharge is implemented in such a way that, with an epilation appliance of the previously mentioned type, the spark discharge is controlled in dependence upon the cyclic plucking out of the hairs so that in particular a spark is issued ahead of every plucking operation in time and/or place. 
     In an advantageous further aspect of the present invention, an electric spark creating an additional pain is produced on the skin prior to the extraction of the hairs with an above mentioned epilation appliance and a method by the means for reducing the sense of pain. This additional pain corresponds in its pain characteristic to the pain of epilation. However, its intensity is preferably lower than the pain of epilation. 
     Further features, advantages and application possibilities of the present invention will become apparent from the subsequent description of embodiments illustrated in more detail in the accompanying drawing. It will be understood that any single feature and any meaningful combination of single features described and/or represented by illustration form the subject-matter of the present invention, irrespective of their summary in the claims and their back reference. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawing, 
     FIG. 1 is a perspective view of an epilation appliance having two groups of first and second electrodes disposed on the rotary cylinder; 
     FIG. 2 is a perspective view of an epilation appliance having first electrodes disposed on the outside of the housing and second electrodes on the rotary cylinder; 
     FIG. 3 is a perspective view of an epilation appliance having a group of second electrodes disposed on a separate carrier; 
     FIG. 4 is a longitudinal sectional view of a rotary cylinder having a group of first and second electrodes; and 
     FIG. 5 is a sectional view of a rotary cylinder taken along the line  80 — 80  of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An epilation appliance (FIG. 1) in accordance with the present invention is comprised essentially of a grip element  4  and an epilation head  6  mounted on top. Inside the housing  8  is a motor, not showing for the sake of simplicity, and a transmission mechanism for driving the clamping device  14  provided in the epilation head. Inside the housing  8  provision is also made for a high-voltage source, which together with the motor is connectable to a supply voltage, in particular a line voltage or a direct voltage from a primary or secondary battery. The high voltage can be a direct voltage or an alternating voltage, a pulsing or modulated or similar voltage, or it may even consist of pulse bursts. 
     At the front of the housing  8  is a switch  10  for turning the epilator on and off and for setting an operating level. A separate control  12  is provided for the high-voltage source to be individually set by the user. 
     The clamping device  14  is a rotary cylinder  14  known in the art and equipped with clamping elements  16  disposed in offset relation to each other. These clamping elements  16  are arranged on the shell face of the rotary cylinder  14  in such a way that there are always two clamping elements  16  in a row and essentially parallel to the axis of rotation of the rotary cylinder. It is also possible, however, for the clamping elements to display any other arrangement on the shell face of the rotary cylinder  14 . One group of clamping elements  16  is constructed as first electrodes  18  with positive electric potential, for example, and one group of clamping elements  16  as second electrodes  20  with negative potential, for example, the electrodes being connected to the high-voltage source. This ensures that, when the cylinder  14  is rotated, at least one of the first electrodes  18  can be moved into contact temporarily with the skin requiring epilation and that at least one of the second electrodes  20  is positioned at least temporarily a distance away from the skin requiring epilation so that a spark can be produced in the air gap between the skin and the first and/or second electrode. 
     In this arrangement it is possible for all the clamping elements of both the first group  18  and the second group  20  to be constructed as electrodes so that a spark can be produced when each individual clamping element  16  approaches the skin requiring epilation. Alternatively it is also possible, however, to construct a different number of clamping elements  16  in the first group  18  than in the second group  20  as electrodes. In this way it is possible to vary the number of spark discharges per revolution of the rotary cylinder  14  as well as the relative spacing, in time and place, of the spark discharges. When a direct voltage is applied as high voltage it is preferred for all the clamping elements  16  of the first group  18  and only every second clamping element  16  of the second group  20  to be connected to the voltage source. 
     As an alternative to the above described embodiment it is also possible for a grip element  4  (FIG. 2) to be fitted with an epilation head  22  having a clamping device  24  with clamping elements  26 . In this alternative, for example, all the clamping elements  26  of the cylinder  24  acting as second electrodes  28  have the same electric potential. The first electrodes  30  and  32  are constructed as sliding contacts and mounted on the top of the housing  34  in such a way as to be in continuous contact with user&#39;s skin while the appliance is being used. Hence the electrodes  30  and  32  produce a continuous contact with the skin while the clamping elements  26  revolving with the rotary cylinder  24  produce a temporary contact with the skin. Consequently a spark is produced in the air gap between the skin and the respective electrode  28  prior to the clamping elements  26  approaching the skin requiring epilation. It is also possible for the first electrodes to be arranged at any other position on the outside of the housing and also for them to be constructed as contact pads, for example, and be connected by cable to the high-voltage source. 
     A further embodiment (FIG. 3) makes provision for an epilation head  36  having a rotary cylinder  38  corresponding essentially to the one of FIG.  2 . In this embodiment the clamping elements  40  are constructed as a group of first electrodes, and a group of second electrodes  46  is arranged on a separate carrier  44  extending essentially parallel to the longitudinal axis of the rotary cylinder  38  along the outside of the housing. The electrodes  46  are constructed in such a way as to be moved a small distance, preferably around 0.6 mm, above the surface of the skin during use. By contrast, the clamping elements  40  of the rotary cylinder  38  are arranged on the shell face of the cylinder  38  in such a way that one clamping element  40  is always in contact with the skin practically without interruption during use. To produce a spark discharge between the second electrodes  46  and the skin the second electrodes  46  are controlled by a control device, not shown, located inside the housing  8  so that the high voltage is applied to only one of the electrodes  46  at a time. 
     The rotary cylinder  14  (FIG. 4) is comprised essentially of the clamping elements  16 , which are divided into one group of first electrodes  18  and one group of second electrodes  20 , the electrodes  18  having a positive potential, for example, and the electrodes  20  a negative potential. Between the two electrode groups  18  and  20  there is an insulator  48  designed to prevent the sparks jumping between the two electrode groups  18  and  20 . The rotary cylinder  14  is mounted for rotary movement on a shaft  50  having either end guided by bushings  52  and  54  in the housing  34  of the epilation head. The clamping elements  16 , on the other hand, are arranged on sleeves  60  and  62  connected to the shaft  50 . At each end of the rotary cylinder  14  provision is made for a contact disk  56  at the one end, and for a disk  58  at the other end, said contact disk  56  being joined to contact pins  64 ,  66  which in turn are in contact with the clamping elements  16  of the first electrode group  18 . The contact disk  56  is also joined to a sliding pin  68  which is connected to a high-voltage source  70  so that an electric potential can be applied to the clamping elements  16  of the first electrode group  18  via the sliding pin  68 , the contact disk  56  and the contact pins  64  and  66 . 
     The second pole of the high-voltage source  70  is connected to the clamping elements  16  of the second electrode group  20  via the bushing  54 , the shaft  50  and the sleeve  62 . These electrically conductive parts are made of an electrically conductive material, preferably brass, nickel, copper, carbon or a ferriferous material or are provided with an electrically conductive coating. 
     The bushing  52 , the sleeve  60  and the disk-shaped insulator  48  are made of an electrically insulating material so that spark discharge between the electrodes of the first group  18  and those of the second group  20  is prevented. 
     The rotary cylinder  14  (FIG. 5) is penetrated essentially diametrically by a strip-shaped clamping element  16  and mounted for rotary movement on the shaft  50  by means of the sleeve  62 . When the epilator is used, the rotary cylinder  14  is moved in the direction of rotation  72  over the surface of the skin  78  requiring epilation. As this occurs, the clamping element  16  approaches the skin  78  so that, upon reaching a distance  74 , a spark  76  is produced between the clamping element  16 , constructed as an electrode, and the skin  78 . The spark  76  will then jump over when the dielectric strength of the air is overcome, i.e., when the voltage-carrying clamping element  16  has approached the skin to the required distance  74 . The air gap between the skin requiring epilation and the electrode—at a discharge voltage of up to 5 KV—equals a distance of up to around 1 millimeter; in particular spark discharge begins at an air gap of 0.6 mm, approximately. 
     In a preferred embodiment the electric voltage is set from 1.0 to 2.5 KV, approximately. This voltage discharges as an inversely proportional function of the distance  74 , meaning that an initial spark discharge can be produced at a distance  74  of 0.6 mm, approximately, and that a spark discharge with a frequency of 2.5 kHz, approximately, takes place at a distance of 0 mm, approximately, i.e. when the electrically conductive clamping element  16  is in contact with the skin.