Patent Publication Number: US-9888757-B2

Title: Epilator

Description:
FIELD OF THE INVENTION 
     The present invention is concerned with an attachment for an epilator and an epilator. 
     BACKGROUND OF THE INVENTION 
     It is known that epilators may comprise a clamping cylinder on which clamping units comprising two clamping elements are arranged. During operation, the clamping cylinder is driven into rotation around its cylinder axis. The clamping units are arranged to be cyclically moved between an open position in which a gap extends between the two clamping elements into which gap hairs can enter and a closed position in which the two clamping element abut on each other at least along a clamping line such that hairs that are clamped in between the clamping elements are plucked from the user&#39;s skin when the clamping unit continues to rotate on the clamping cylinder while being in the closed position. EP 1 796 501 B1 generally describes a clamping cylinder having a plurality of clamping units. 
     It is a general desire to increase the efficiency of epilators, i.e. to increase the number of hairs that are clamped and plucked. 
     It is hence an object of the present disclosure to provide an attachment for an epilator and an epilator having an increased clamping and plucking efficiency over the known devices. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect there is provided an attachment for an epilator or an epilator comprising at least a clamping unit for clamping and plucking hairs, the clamping unit being arranged for driven movement along a hair capture direction, the clamping unit comprising a moveable clamping element having a clamping section and at least a winged section, wherein the clamping section has a clamping surface and the winged section has a guiding surface, which guiding surface angles outwards away from the clamping surface at least with respect to the hair capture direction; and a fixed clamping element having a clamping section and at least a winged section, wherein the clamping section has a clamping surface and the winged section has a guiding surface, which guiding surface angles outwards away from the clamping surface at least with respect to the hair capture direction; wherein the clamping unit is arranged for cyclical movement between an open position in which a gap for receiving hairs and having a minimum width in a width direction perpendicular to the hair capture direction extends between the clamping surfaces of the moveable clamping element and the fixed clamping element and a closed position in which the clamping surfaces of the moveable clamping element and the fixed clamping element abut on each other at least along a clamping line; and wherein the guiding surface of the moveable clamping element defines a first side of a funnel for guiding hairs towards the gap and the guiding surface of the fixed clamping element defines a second side of the funnel, wherein the width of the hair guiding surface of the fixed clamping element measured in a width direction perpendicular to the hair capture direction is larger than the respective width of the hair guiding surface of the moveable clamping element. 
     In accordance with one aspect there is provided an attachment for an epilator or an epilator, optionally in accordance with any other aspect of the present disclosure, comprising at least a clamping unit comprising a clamping element having a clamping section having a clamping surface and a winged section having a guiding surface that angles away from the clamping surface for guiding hairs, wherein the guiding surface has a three-dimensional shape wherein the guiding surface is inclined (for plane and or curved surfaces) or bent (for curved surfaces) in two different directions. Thus the guiding surface extends in a twisted way or is at least in two directions inclined. 
     In accordance with one aspect there is provided an attachment for an epilator or an epilator, optionally in accordance with any other aspect of the present disclosure, comprising at least a clamping unit comprising at least a moveable clamping element having a clamping section having a clamping surface and a winged section having a guiding surface that angles outwardly away from the clamping surface, wherein the winged section is pre-stressed such that it angles away from the clamping section in an unconstrained situation at a predetermined angle and is flexibly or pivotably arranged such that the angle with which the winged section angles away from the clamping element can be modified by applying a force onto the winged section in a direction that acts against the pre-stress force. 
     In accordance with one aspect there is provided an attachment for an epilator or an epilator, optionally in accordance with any other aspect of the present disclosure, comprising at least a clamping unit, the clamping unit having a movable clamping element having a clamping surface and a second clamping element having a clamping surface that are arranged to be cyclically movable with a closure velocity between an open position in which a gap having a minimal width extends between the two clamping surfaces and a closed position in which the clamping surfaces abut on each other over a length, which clamping unit is arranged to be movable at a movement velocity relative to a housing of the epilator, wherein the effective hair catching area of the clamping unit in relation to the closure time is at least 3500 mm 2 /s, in particular wherein the effective hair catching area of the clamping unit in relation to the closure time is at least 4000 mm 2 /s, further in particular wherein the effective hair catching area of the clamping unit in relation to the closure time is at least 4500 mm 2 /s. 
     In accordance with one aspect there is provided an attachment for an epilator or an epilator comprising at least a clamping unit for clamping and plucking hairs that is arranged for driven movement relative to a housing of the epilator along a hair capture direction, the clamping unit comprising a moveable clamping element having a clamping surface and a hair guiding surface and a fixed clamping element having a clamping surface and a hair guiding surface, wherein the moveable clamping element and the fixed clamping element are arranged to be cyclically moveable between an open position in which the two clamping surfaces have a minimal distance such that a gap for receiving hairs is formed between them and a closed position in which the two clamping surfaces abut on each other, wherein the two hair guiding surfaces form a funnel in front of the gap in the open position with respect to the hair capture direction, which funnel has a width measured in a width direction perpendicular to the hair capture direction, which funnel width is given by the sum of the width of the hair guiding surface of the moveable clamping element, the gap width, and the width of the hair guiding surface of the fixed clamping element, wherein the width of the hair guiding surface of the fixed clamping element is larger than the width of the hair guiding surface of the moveable clamping element, optionally wherein the width of the hair guiding surface of the fixed clamping element is about as large as the sum of the width of the hair guiding surface of the moveable clamping element and the gap width. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will be further elucidated by a detailed description of example embodiments and with reference to figures. In the figures: 
         FIG. 1  is a generic depiction of an epilator comprising an attachment and a housing section; 
         FIG. 2  is a depiction of the attachment shown in  FIG. 1  in a detached state; 
         FIG. 3  is a depiction of an example embodiment of a clamping cylinder in accordance with at least one aspect of the present disclosure; 
         FIG. 4A  is a schematic depiction of an example embodiment of a clamping unit in accordance with at least one aspect of the present description shown in an open position; 
         FIG. 4B  is a depiction of the clamping unit shown in  FIG. 4A  in a closed position; 
         FIG. 5A  is a schematic depiction of another example embodiment of a clamping unit in accordance with at least one aspect of the present description shown in an open position; 
         FIG. 5B  is a depiction of the clamping unit shown in  FIG. 5A  in a closed position; and 
         FIG. 6  is a cross sectional cut though a clamping cylinder, the cut taken in a plane being perpendicular to the longitudinal cylinder axis. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An attachment for an epilator or an epilator in accordance with any aspect of the present disclosure may in particular comprise a carrier, e.g. a clamping cylinder or a clamping disc, on which at least one clamping unit is arranged, which clamping unit comprises two clamping elements, at least one of these clamping elements being a moveable clamping element and the other clamping element being either also a moveable clamping element or a fixed clamping element. The clamping unit forms a discrete portion of the perimeter of the clamping cylinder that protrudes from the clamping cylinder. The clamping unit (i.e. the carrier—e.g. a clamping cylinder) may be arranged for driven movement along a hair capture direction. Each of the clamping elements has a clamping section having a clamping surface. The clamping elements of the clamping unit are arranged to be cyclically moveable between an open position in which a free gap having a minimal gap width extends between the clamping surfaces of the clamping elements such that hairs can be fed into the gap (i.e. the clamping surfaces are arranged vis-à-vis) and a closed position in which the clamping surfaces abut on each other at least along a clamping line (as is explained further below, the clamping surfaces may abut on each other also in a laminar manner). Hairs that are clamped between the clamping surfaces in the closed position will eventually be plucked from the skin when the clamping unit continues to be moved along the hair capture direction relative to the skin of a user while being in the closed position. The clamping elements may in particular each comprise a clamping section on which the clamping surface is arranged and a winged section that is arranged in front of the clamping unit with respect to the hair capture direction and on which a guiding surface is arranged. The winged section angles outwardly away from the clamping section with respect to the hair capture direction such that each of the guiding surfaces of the winged sections of the two clamping elements of the clamping unit form one side of a funnel for guiding hairs towards the gap extending between the clamping surfaces while the clamping unit is in the open position and while the clamping unit is being closed, i.e. hairs are guided into the narrowing gap by the guiding surfaces until the gap is closed (i.e. until the gap is so small that hairs do not feed into the gap anymore). The two such formed sides of the funnel each have a width that is measured in a width direction perpendicular to the hair capture direction (wherein the width direction is also essentially perpendicular to the clamping surfaces in the closed position), wherein in particular in accordance with at least one aspect of the present disclosure where the clamping unit comprises a moveable clamping element and a fixed clamping element, the width of the guiding surface of the moveable clamping element is smaller than the width of the guiding surface of the fixed clamping element. In some embodiments, the width of the guiding surface of the fixed clamping element may then be chosen about as large as the sum of the width of the guiding surface of the moveable clamping element plus the width of the gap in the open position. 
     In some embodiments of an attachment for an epilator or an epilator in accordance with at least one aspect of the present disclosure, a plurality of clamping units is arranged on a clamping cylinder that is arranged for driven movement around its longitudinal centre axis. Thus the clamping unit is arranged on a clamping cylinder rotating around an axis of rotation and the moveable clamping element is moveable in a direction perpendicular to the hair capture direction or in other words in a direction parallel with said axis of rotation (which is the same axis as the clamping cylinder longitudinal centre axis). The width direction is then parallel to the longitudinal cylinder axis. The clamping units may then be arranged such that the gaps of the clamping units in their open positions do not overlap in the longitudinal cylinder direction, i.e. such that the sum of the widths of all gaps of the plurality of clamping units covers an effective width of the clamping cylinder (which is the width over which the clamping cylinder epilates) by less than 100%, in particular less than 90%, less than 80%, less than 70% or less than 65%. Thus the sum of all gaps between the clamping sections of all clamping units is smaller than the total width of the clamping cylinder. In some embodiments, where each of the plurality of clamping units has a funnel formed in front of the clamping unit, the sum of the total widths of all funnels of all clamping units covers the effective width of the clamping cylinder by more than 100%, in particular more than 200%, or more than 300%. Thus a high hair removal efficacy is achieved although less clamping gaps/clamping units are provided. 
     In some embodiments of an attachment for an epilator or an epilator in accordance with at least one aspect of the present disclosure, at least one clamping unit comprising two clamping elements is arranged on a clamping cylinder and the length along which two clamping elements abut on each other in a closed position of the clamping unit is in a range of between about 8% to 12% of the perimeter of an enveloping cylinder of the clamping cylinder, in particular in a range of between about 8.5% and about 10.5%, further in particular has a value of about 10%. 
     In some embodiments of an attachment for an epilator or an epilator in accordance with at least one aspect of the present disclosure, a carrier, e.g. a clamping cylinder or a clamping disc, has a lower lying surface not intended for contact with the skin of a user during regular operation, which lower lying surface has a microscopic or macroscopic texture or has a surface coating or surface layer of a friction enhancing material that has an enhanced friction with hair when compared to the friction between the base material from which the carrier is made and hair. The macroscopic texture may in particular be realized as ridges extending in longitudinal cylinder direction, which ridges may have a height in a range of between about 0.02 mm to about 2.0 mm, in particular of between about 0.05 mm to 0.5 mm, further in particular a value of about 0.1 mm. In addition, the circumferential distance between the ridges may lie in a range of between 0.2 mm to about 2.0 mm. The microscopic texture may in particular be achieved by a certain roughness, which may be realized by filling material in the base material, e.g. glass fibers or ceramic particles. 
     In some embodiments of an attachment for an epilator or an epilator in accordance with at least one aspect of the present disclosure, at least a clamping unit is arranged on a carrier, e.g. a clamping cylinder or a clamping disc, which clamping unit has a clamping element having a clamping section that has a clamping surface and a winged section that has a guiding surface, which guiding surfaces angles outwardly away from the clamping surface (i.e. the winged section angles outwardly away from the clamping section) and wherein the guiding surface has a three-dimensional shape, i.e. the guiding surface does not lie in a plane in a Cartesian coordinate system. 
     In some embodiments of an attachment for an epilator or an epilator in accordance with at least one aspect of the present disclosure, at least a clamping unit is arranged on a carrier, e.g. a clamping cylinder or a clamping disc, which clamping unit has a moveable clamping element having a clamping section and a winged section, wherein the winged section is flexible or is hinged at the clamping section and wherein the winged section is under a pre-stress such that it outwardly angles away from the clamping section at a preset value in an unconstraint value and wherein the angle with which the winged section angles away from the clamping section can be modified (in particular reduced) by a force acting against the pre-stress. In particular, the force acting against the pre-stress may be provided by a fixed wall element against which a free end of the winged section abuts, while the clamping unit is in an open position and along which fixed wall element the free end of the winged section will glide at least during a part of the movement when the moveable clamping element is moved such that the angle with which the winged section angles away from the clamping section is modified (in particular is increased). 
       FIG. 1  is a depiction of an example embodiment of an epilator  1  having a detachable attachment  10  and a housing section  20  that can be held in a user&#39;s hand. The housing section  20  may comprise an on/off-switch  21  (which may also be used to switch between different speed settings) and/or a grip area  22  that may be made from a (in particular structured) friction-enhanced material, e.g. a thermoplastic elastomer or a natural rubber. The housing section may also comprise a drive and/or an energy source (e.g. an accumulator). In the shown embodiment, the attachment  10  comprises a clamping cylinder  11  having a plurality of clamping units  12 . The clamping cylinder  11  is arranged for driven movement around its centre axis A (i.e. the longitudinal cylinder axis) such that the clamping units  12  move along a hair capture direction D. The attachment  10  may comprise a detachable cap unit  13  havening an opening  14  through which the clamping cylinder  11  extends for being brought into contact with a user&#39;s skin. The opening  14  defines an effective width E of the clamping cylinder  11  measured in longitudinal cylinder direction, which is the width over which the epilator can clamp and pluck hairs during operation. A user will typically move the epilator over the skin along a movement direction M which coincides with the hair capture direction D. As will be explained in more detail further below, the clamping units  12  each comprise two clamping elements of which at least one clamping element is arranged to be moveable. The clamping elements are arranged for cyclical movement between an open position in which hairs can enter into a gap extending between clamping surfaces of the clamping elements and a closed position in which the clamping surfaces abut on each other at least along a clamping line. As is generally known, hairs that are clamped by the clamping units in the closed position will be eventually plucked from the skin when the clamping unit continues to move along the hair capture direction D while the clamping unit continues being in the closed position. Patent document EP 1 796 501 B1 generally describes an epilator having a clamping cylinder with a plurality of clamping units; the content of said document shall be incorporated herein by reference. 
     While in  FIG. 1  and in the below example embodiments, an epilator or an attachment for an epilator is discussed that has a clamping cylinder carrying the clamping unit, the clamping unit may be arranged at any other carrier arranged for being driven along a hair capture direction. E.g. the clamping unit may be provided at a disc that is arranged for driven rotation around its centre axis. 
       FIG. 2  shows an example embodiment of an attachment  10  for an epilator shown in its detached state, which attachment  10  is in accordance with the attachment discussed with respect to  FIG. 1 . While it is here shown that an attachment for an epilator is detachable, this shall not exclude that the features discussed with respect to an attachment can also be realized at an epilator not having a detachable attachment, i.e. where the clamping unit is arranged at a carrier (e.g. a clamping cylinder) at the epilator. 
       FIG. 3  shows an example embodiment of a clamping cylinder  30  shown in a perspective view. A plurality of clamping units  31  is arranged on the clamping cylinder  30 . Each clamping unit  31  comprises a fixed clamping element  32  and a moveable clamping element  33 . The fixed clamping elements  32  may be made integral with the clamping cylinder base material, e.g. the fixed clamping units may be made from a plastic material and may be manufactured by a plastic injection molding process together with a part of the clamping cylinder. As has been mentioned before, the clamping elements  32 ,  33  are arranged for cyclic movement between an open position in which a gap  34  extends between the clamping elements such that hairs can enter into the gap and a closed position in which the clamping elements abut on each other and thus clamp hairs having been in the gap. At least one wing section of one of the moveable or fixed clamping element comprises an outermost arc shaped portion. The clamping section of at least one of the moveable or fixed clamping element comprises also an outermost arc shaped portion. Thus the clamping elements  32 ,  33  have outer surfaces  32 A,  33 A that essentially lie on the surface of an enveloping cylinder. The outer surfaces  32 A,  33 A are intended for contact with a user&#39;s skin during operation. A regular pattern of ridges  36  extending in longitudinal cylinder direction on a lower level of the clamping cylinder surface (i.e. on a level of the clamping cylinder below the enveloping cylinder—see  FIG. 6 ) is provided in the shown example embodiment. In some embodiments, the enveloping cylinder may have a diameter of about 19 mm and the cylinder defined by the lower level surface (i.e. the surface that is defined by the top parts of the ridges) may have a diameter of about 17 mm. In some embodiments, the ridges may have a height of about 0.1 mm. The geometry and function of the ridges (or similar structures) will be explained further below in more detail, but such structures as the shown ridges serve to erect hairs that lie close to the skin. The clamping cylinder  30  comprises an axis  39  that may be borne by respective bearings provided at the attachment so that the clamping cylinder  30  is enabled to rotate around its central axis C in rotation direction R. A spring  38  presses the clamping cylinder parts together and provides the clamping force with which the clamping elements are pressed together in their closed position. The clamping cylinder  30  may also comprise at least one gear wheel  37  provided for meshing with a further gear wheel that may be driven during operation, which further gear wheel may be a part of the housing section. 
     While the example embodiment of a clamping cylinder shown in  FIG. 3  has a plurality of clamping elements, it is noted that in accordance with the present disclosure it is sufficient that a clamping cylinder has at least one clamping unit. It is also noted that in case of two or more clamping units, the clamping units may each be different, e.g. one clamping unit may comprise a fixed and a moveable clamping element, another clamping unit may comprise two moveable clamping units. It is also generally noted that all features shown and discussed with respect to an example embodiment do not necessarily need to be seen as disclosed only in that combination but that all features that can be separated without violating the gist and scope of the present disclosure shall be considered as being disclosed independently from all other features. E.g. the ridges provided on the clamping cylinder discussed in connection with  FIG. 3  may not only be an optional feature but may indeed be considered as an independent aspect of the present disclosure. 
     It is noted that in general an epilation cylinder may be equipped with a friction enhanced lower level surface, which friction enhancement (with respect to hairs) may be achieved by macroscopic structures (e.g. ridges as shown in and discussed with respect to  FIG. 3 ) or by microscopic structures (e.g. a certain roughness) or by a material choice providing an increased friction with hairs (e.g. keratin filaments) when compared to the plastic material used for making the clamping cylinder. E.g. the lower level surface of the clamping cylinder may have a coating of an artificial rubber. The friction enhancement of a lower level surface was found to potentially increase the number of hairs that become erected out of a position where they lie close to the skin. Hairs lying close to skin still have a certain elevation above the skin surface. The lower level surface is thus retracted from the enveloping cylinder by a typical value of between about 0.25 mm to about 3.0 mm, in particular of between about 0.5 mm to 1.5 mm, in order to provide a good hair erection effectiveness. With additional hairs being erect, the efficiency of the epilator is likely to be increased. Whether the enhanced friction of the lower level surface of the epilator is provided by microscopic or macroscopic structures realized in the base material of the clamping cylinder or by a coating or layer of a different material covering the lower level surface, this feature is considered as an independent aspect of the present disclosure, while this feature may also be combined with all other features of the present disclosure. 
       FIG. 4A  shows an example embodiment of a schematically drawn clamping unit  100  shown in an open position, which clamping unit  100  may be arranged on a clamping cylinder as shown in  FIG. 3 . The clamping unit has a moveable clamping element  110  and a fixed clamping element  120  that are arranged vis-à-vis. The moveable clamping element  110  may be made from a metal sheet such as a stainless steel sheet material, while it should not be excluded that the moveable clamping element may be made from other materials such as plastic or reinforced plastic. The fixed clamping element  120  may be an integral part of at least a part of a clamping cylinder and may be made from a plastic material (e.g. via a plastic injection molding process), in particular from a plastic material that is reinforced by a filling substance such as glass fibers or ceramic particles. 
     The moveable clamping element  110  has a clamping section  111  and a winged section  112 . The clamping section  111  extends in a length direction L with a length L 1  and has a clamping surface  113 . The length direction L coincides with the hair capture direction (see reference numeral D in  FIG. 1 ) along which the clamping unit  100  will be moved during operation. The fixed clamping element  120  has a clamping section  121  and a winged section  122 . The clamping section  121  extends in a length direction L with a length L 1  and has a clamping surface  123  that faces the clamping surface  113  of the moveable clamping element  110 . The position of the two oppositely arranged clamping elements  110 ,  120  coincide in length direction L so that in a closed position ( FIG. 4B ), the effective clamping length is also L 1 . In the open position as shown in  FIG. 4A , a gap  130  extends between the clamping surfaces  113 ,  123  of the moveable and fixed clamping elements  110 ,  120 . The gap  130  has in the open position a minimal gap width W 2  in a width direction W (the width direction W being perpendicular to the length direction L, i.e. the width direction is perpendicular to the hair capture direction). As the clamping sections  111 ,  121  may not necessarily be parallel to each other in the open position, the minimal gap width W 2  may not be the same over the whole gap extension. The minimal gap width W 2  is sized such that hairs can feed into the gap. While the diameter of typical human hairs may lie in a range of 80 micrometer±40 micrometer, the gap width W 2  may lie in a range of between about 0.1 mm to about 2.0 mm, in particular in a range of between about 0.4 mm to about 1.4 mm. In some embodiments, the minimal gap width W 2  may be about 0.6 mm. 
     The winged section  122  of the fixed clamping element  120  has a guiding surface  124  that outwardly angles away from the clamping surface  123  of the clamping section  121  with an angle  125  such that a first side of a funnel is formed on a front side  101  of the clamping unit  100 . The front side  101  of the clamping unit  100  is the side from which hairs approach the clamping unit  100  during operation, when the clamping unit  100  is moved along the hair capture direction that here coincides with the length direction L. The guiding surface  124  of the winged section  122  extends in length direction L over a length L 2  and in the width direction W over a width W 3 . The winged section  112  of the moveable clamping element  110  has a guiding surface  114  that outwardly angles away from the clamping surface  113  of the clamping section  111  with an angle  115  such that a second side of the funnel is formed. The guiding surface  114  of the winged section  112  extends in length direction L over a length L 3  and in the width direction W over a width W 1 . The total effective width W 4  over which the clamping unit  100  thus may catch and hence plug hairs is given by the sum of the widths&#39; of the winged sections  112  and  122  and of the gap width W 2 , W 4 =W 1 +W 2 +W 3 . The total effective width over which the clamping unit catches hairs may be between 2 mm to 7 mm which is the sum of the widths&#39; of both adjacent winged sections within a clamping unit and of the gap width between both clamping sections in its open position. 
     As is generally known, the moveable clamping element  120  may be spring loaded such that the clamping unit  100  is in the open position as long as a respective actuator is not forcing the two clamping elements  110 ,  120  together. 
     During operation, the clamping unit  100  will be moved relatively to the user&#39;s skin such that hairs growing on the skin will approach the clamping unit  100  from the front side  101  of the clamping unit  100  and will be guided by the guiding surfaces  114  and  124  into the gap  130 , which gap will be closed until the clamping surfaces  113 ,  123  are urged together so that hairs in the gap  130  will then be clamped and will eventually be plugged from the skin due to the relative movement between the clamping unit  100  and the user&#39;s skin. The relative movement between the clamping unit  100  and the user&#39;s skin typically has two components: the usually faster component is provided by the drive of the epilator that drives the clamping unit  100  into motion, e.g. by rotating a clamping cylinder into rotation, and by a usually slower component that is given by the movement the user introduces by manually moving the epilator over the skin. The clamping cylinder may be driven with a number of rotations per minute (rpm) that lie in a range of between about 500 rpm to about 5000 rpm, in particular in a range of between about 1000 rpm to about 2500 rpm. In some embodiments, the clamping cylinder may rotate in a range of between about 1300 rpm to about 1900 rpm. 
     In some embodiments, the width W 3  by which the guiding surface  124  of the fixed clamping element  120  extends in width direction W may be set to a value that allows hairs that are caught at the outer edge of the first side of the funnel to become clamped by the clamping unit. This value may in particular depend on the typical hair length of hairs that will become epilated and a typical time period between epilation events. A typical growth length for hairs growing on human skin is about 0.2 mm per day. A typical period between epilation events may be 2 weeks, i.e. 14 days, so that the hair has grown 2.8 mm between respective epilation events. During epilation, some hairs that are not plucked from the skin typically break about 0.5 mm-10 mm below the skin surface, so that the hair length of the broken hairs above the skin may roughly be in the range of 1.8 mm to 2.3 mm (hairs that are plucked together with at least a part of the hair root require a certain period for growing again as first the hair root needs to be rebuild). Assuming that a certain length of the hair needs to extend into the gap of the clamping unit for reliable epilation, typical values for the width W 3  of the guiding surface of the fixed clamping element may thus lie in a range of between about 0.4 mm to about 2.0 mm. As the moveable clamping element  110  moves towards the fixed clamping element  120 , the effective width of the second side of the funnel is determined by the sum of the gap width W 2  and the width W 1  of the guiding surface  114  of the moveable clamping element  110 . Thus, a symmetric setting of the funnel widths would require W 1  to be set to W 3  minus W 2 , W 1 =W 3 −W 2 . That means that for a symmetric guiding efficiency the winged sections may be asymmetrically realized, e.g. the guiding surface  114  of the winged section  112  of the moveable clamping element  110  may have a shorter width W 1  in comparison to the width W 3  of the guiding surface  124  of the winged section  122  of the fixed clamping element  120 . In other words the fixed clamping unit comprises a winged section that is longer and/or with broader width extension than the winged section of the moveable clamping unit. 
     In some embodiments, the length L 2  of the guiding surface  124  of the winged section  122  of the fixed clamping element  120  may lie in a range of between about 2 mm and about 8 mm and the respective width W 3  may be in a range of between about 0.5 mm and about 3.0 mm. In some embodiments, the length L 2  may be about 5 mm. In some embodiments, the width W 3  may be about 1.5 mm, which may be considered a value that nicely considers the above mentioned hair length of broken hairs after two weeks and thus provides an adapted high efficiency based on the typical hair length. A larger width W 3  may increase efficiency further if hairs are longer (e.g. in case that a longer period lies between epilation events), but a larger width w 3  also requires more available space on the carrier (e.g. the clamping cylinder) on which the clamping unit is arranged. In some embodiments, the length L 3  of the guiding surface  114  of the winged section  112  of the moveable clamping element  110  may be in a range of between about 0.1 mm and about 4.0 mm and the width W 1  may be in a range of between about 0.1 mm and about 2.0 mm. In some embodiments, the length L 3  may be about 2 mm. In some embodiments, the width W 1  may be about 0.8 mm. 
     In some embodiments, the angle  115  between the clamping surface  113  and the guiding surface  114  of the winged section  112  of the moveable clamping element  110  and/or the angle  125  between the clamping surface  123  and the guiding surface  124  of the winged section  122  of the fixed clamping element  120  may lie in a range of between about 5 degree to about 45 degree, in particular in a range of between about 10 degree to about 30 degree. In some embodiments, the respective angles  115 ,  125  may be different; in particular, the angle  115  may be larger than the angle  125 . In some embodiments, the angle  115  between the clamping surface  113  and the guiding surface  114  of the winged section  112  of the moveable clamping element  110  may be about 22.5 degrees. In some embodiments, the angle  125  between the clamping surface  123  and the guiding surface  124  of the winged section  122  of the fixed clamping element  120  may be about 16 degrees. 
     In some embodiments, alternatively or additionally the width W 3  by which the guiding surface  124  of the fixed clamping element  120  extends in width direction W is about the same as the sum of the minimal gap width W 2  and of the width W 1  of the guiding surface  114  of the winged section  112  of the moveable clamping element  110 , W 3 ≈W 1 +W 2 , in particular wherein W 3  differs by not more than 10% from W 2 +W 1 , optionally by not more than 5%, further in particular where W 3  is identical to W 1 +W 2 , W 3 =W 1 +W 2 . 
       FIG. 4B  schematically shows the clamping unit  100  shown in  FIG. 4A  in its open position in its closed position. In order to reach the closed position, the moveable clamping element  110  is moved generally along a closure direction M as indicated in  FIG. 4A  towards the fixed clamping element  120  such that in the closed position the clamping surface  113  of the moveable clamping element  110  abuts onto the clamping surface  123  of the fixed clamping element  120  at least along a clamping line, optionally wherein the clamping surfaces  113 ,  123  abut on each other in a laminar manner. While it may be sufficient that the clamping surfaces only abut on each other along a clamping line, a high pressure may be present along the clamping line and hairs may be cut or may break during the plucking procedure due to this high pressure. Hence, a laminar clamping area may tend to reduce the number of hairs that are cut or that break. 
     One may define an effective hair catching area A, which is the area from which hairs are clamped by a clamping unit, neglecting the effect of guiding surfaces that may guide hairs from an enlarged area into the gap. The effective hair catching area A is then depending on the clamping length l of the clamping unit, the closure velocity c with which the clamping elements of the clamping unit are closed, the gap width d, and the velocity v with which the clamping unit is moved relative to the skin, so that A=d(l−½ v·d/c). A typical closure speed c may lie in the range of between about 0.7 m/s to about 1.3 m/s, in particular at about 1 m/s. Thus, the effective hair catching area in relation to the closure time for a closure speed of 1000 mm 2 /s for a typical clamping length of 4.0 mm as known from prior art devices, a gap width of 0.9 mm and a movement velocity of 2000 mm/s is 2790 mm/s. The overall hair epilation effectiveness will become increased if the parameters of a clamping unit and the epilator are chosen such that the effective hair catching area in relation to the closure time is at least 3500 mm 2 /s or at least 4000 mm 2 /s or at least 4500 mm 2 /s. 
       FIG. 5A  is a schematic depiction of a clamping unit  200  of an epilator in accordance with at least an aspect of the present disclosure, which clamping unit  200  is shown in an open position. The clamping unit  200  comprises a moveable clamping element  210  and a fixed clamping element  220 . Similarly to the clamping unit  100  shown in  FIGS. 4A and 4B , the moveable clamping element has a clamping section  211  and a winged section  212 , where the clamping section  211  has a clamping surface  213  and the winged section  212  has a guiding surface  214  that angles outwardly away from the clamping surface  213  at an angle  215 . Accordingly, the fixed clamping element  220  has a clamping section  221  and a winged section  222 , where the clamping section  221  has a clamping surface  223  and the winged section  222  has a guiding surface  224  that angles outwardly away from the clamping surface  223  at an angle  225 . The clamping surfaces  213  and  223  are arranged essentially opposite to each other and are separated in the open position by a gap  230  that is sized to receive hairs. In the shown example embodiment, the winged section  212  of the moveable clamping element  210  is hinged at the clamping section  211  with a hinge  219  and the winged section  211  has a free end  216  that is in contact with a stopper element  240 . The hinge  219  may be realized by an elastic material arranged between the clamping section  211  and the winged section  212 , which both may be made from a metal sheet material. The winged section  212  is under a pre-stress F such that the angle at which the guiding surface  214  would angle outwardly away from the clamping surface  213  in an unconditioned situation would be larger than angle  215  indicated in  FIG. 5A , which angle  215  is determined by the relative position of a stopper element  240  providing a constraint for the winged section  212  to move under the present pre-stress F. As is indicated by arrow N, the moveable clamping element  210  will be moved towards the fixed clamping element  220  in order to achieve the closed position shown in  FIG. 5B . When the movable clamping element  210  is moved along direction N, the free end  216  of the winged section  212  of the moveable clamping element  210  will stay in contact with the stopper element  240  due to the acting pre-stress F and will move along direction P. 
       FIG. 5B  schematically shows the closed position of the clamping unit  200  shown in  FIG. 5A . In the closed position, the clamping surfaces  213 ,  223  of the moveable and the fixed clamping elements  210 ,  220  abut on each other at least along a clamping line. In the closed position, the guiding surface  214  of the winged section  212  of the moveable clamping element  210  is angled outwardly away from the clamping surface  213  at an angle  215 A that is larger than the angle  21  the respective surfaces have in the open position shown in  FIG. 5A . 
     It is noted that the provision of a winged section of a moveable clamping element being under a pre-stress such that the width of the guiding surface of the winged section increases when the clamping unit is closed is considered as an independent aspect of the present disclosure, while it shall not be excluded that this feature may be combined with all other features described in the present disclosure. 
     In some embodiments, a plurality of 40 clamping units as shown in  FIG. 4A or 5A  may be arranged on a clamping cylinder as shown in  FIG. 3 . The clamping cylinder may have an effective clamping width of 31.9 mm, while the gap width of each clamping unit may be 0.6 mm and the total funnel width of each clamping unit may be about 2.6 mm. Then, assuming that the gaps of the clamping units are arranged on the clamping cylinder such that they do not overlap in longitudinal cylinder axis direction, the total gap width (i.e. the sum of all the 40 gap widths of each 0.6 mm) is 24 mm, which means that the clamping cylinder has a gap coverage of only about 61%. On the other hand, as the added total funnel width of all clamping units is 104 mm, this means that the clamping cylinder is covered by the funnels at about 326%. In other words, each hair growing on the skin may get clamped and plucked by more than three clamping units per revolution of the clamping cylinder. It is considered a general aspect of the present disclosure that the gap coverage of an epilation cylinder is less than 100% while the funnel coverage is above 100%. In particular, the gap coverage may be in a range of between about 20% to about 95% (in particular of between about 50% to about 80%) and additionally or alternatively the funnel coverage may be in a range of about 105% to about 500% (in particular of between about 150% to about 450% and further optionally where the lower funnel coverage value may be at least 200% or even at least 300%). It has been found that a distance between clamping units in longitudinal cylinder axis direction that is larger than the gap width (in particular wherein the distance is at least 25% larger than the gap width or further in particular wherein the distance is at least 30% larger than the gap width) and optionally additionally with a circumferential arrangement of the clamping units such that each clamping unit has a different angular position on the circumference of the clamping cylinder (e.g. in case of 40 clamping units, the angular distance between the clamping units may be 9 degrees) supports the provision of enough space to realize the large funnel widths for the clamping units. 
       FIG. 6  is a cross sectional cut through an example embodiment of a clamping cylinder  300 , where the cross sectional cut was taken in a plane perpendicular to the longitudinal cylinder axis. A movable clamping element  310  can be seen that has a clamping surface  313  that extends along a clamping length l (the clamping length l being measured at the top level of the moveable clamping element  310 , which top level is defined by the top surface  310 A of the moveable clamping element  310 , which top surface  310 A is intended to contact the skin of a user during operation). It is also noted that in the shown embodiment, the outer surface  310 A of the moveable clamping element follows the curvature of the cylinder. Also, three cuts through fixed clamping element parts can be seen, one of which is exemplary identified as fixed clamping element  320  having a top surface  320 A intended for contact with the skin of a user during operation. The outer surfaces  310 A,  320 A lie on an outer enveloping cylinder that has a diameter D 1 , which diameter D 1  may lie in a range of between about 10 mm to about 40 mm. It can further be seen in  FIG. 6  that a regular pattern of ridges  336  (which may extend parallel to the cylinder axis as is shown in  FIG. 3 ) is arranged on a lower level cylinder surface, which lower level cylinder is coaxial with the enveloping cylinder and has a diameter D 2 , where D 2 &lt;D 1 . In some embodiments, D 2  may be around 80% of D 1 . In some embodiments, the clamping length l extends over about 36 degrees of the angular range measured from the centre point of the cross sectional cut or in other words, the clamping length l may be about 10% of the perimeter of the outer enveloping cylinder, i.e. l=0.1·2π·D 1 / 2 . Generally, the clamping length l may be in a range of between about 8% to about 12% of the perimeter of the enveloping cylinder, in particular it may lie in a range of between about 8.5% to about 10.5%. While generally an increase of the clamping length l may increase the efficiency of the clamping cylinder, the clamping element also needs to have contact with the skin over its clamping length as otherwise the efficiency may not further increase due to non-clamped hairs. It has been found that a clamping length of about one tenth of the perimeter of the clamping cylinder defines a compromise between efficiency increase due to length increase and reliable skin contact over the full length extension. 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
     Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.