BACKGROUND

As is well known to those skilled in the art, thick calluses or corns are typically formed on the palms of the hands or the soles of the feet when the epidermis of the palms or the soles becomes partially keratinized due to frequently repeated contact of the hands or feet with a variety of hard or coarse surfaces over time. For example, calluses on the hands are often caused by the regular handling of an object that puts pressure on the hand, such as tools or sports equipment. Calluses and corns on the feet are often caused by pressure from footwear such as tight shoes, high-heeled shoes, loose shoes, and thin-sole shoes. The repeated pressure due to contact causes the skin to die and form a hard, protective surface.

Calluses and corns can cause discomfort and can also become painful. Moreover, calluses or corns crack due to, for example, dry or cold weather, thus allowing the dermis under the epidermis to be damaged. Therefore, it is often necessary to periodically remove such calluses or corns from the palms of the hands or soles of the feet. Such removal of calluses or corns from the hands or feet is commonly called "a pedicure."

During a pedicure, calluses and dry, flaky skin are abraded or scraped from the bottom of the feet. Typically, the feet are soaked in a warm bath and/or a topical formula is applied to soften the skin. Once the warm water and/or a topical formula has softened the skin on the feet, the bottoms of the feet are manually scrubbed with either a pedicure sander comprised of an abrasive sanding pad attached to a durable plastic handle, a callus rasp, or a pumice stone. Additionally, some technicians will use a corn and callus plane comprised of a stainless steel head with a raised shaving blade to slice thick, tough callus from the feet.

These conventional methods and apparatuses for callus removal are time consuming, laborious, inefficient, and often painful. Additionally, some of the conventional instruments present hazards. In particular, a callus plane may cause serious injury if used improperly. Accordingly, to reduce the risks and deleterious effects of the manual process, attempts have been made to automate the process of removing skin imperfections from the feet and hands. For example, several electrically powered rotary devices with sandpaper-like contact surfaces have been devised for grooming hands and feet, one such device being sold under the brand name "Pedi-Smooth." SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In accordance with aspects of the present disclosure, a workpiece is provided. The workpiece can be used with a personal care appliance having a drive system. The workpiece includes a movable base portion configured to be operatively coupled to the drive system and a disc plate mounted on the moving base portion. The disc plate in some embodiments includes an outwardly facing contact surface having an abrasive disposed thereon. The abrasive, in some embodiments, is configured to exfoliate a partially keratinized area of an epidermis when placed in contact therewith.

In some embodiments, the abrasive includes a plurality of abrasive elements. The one or more abrasive elements in some embodiments can be characterized by one or more of the following features, in any combination: the one or more abrasive elements extends outwardly from the contact surface to a height of about 0.003 inches (0.0762 millimeters) to about 0.008 inches (0.203 millimeters); the one or more abrasive elements of the plurality of abrasive elements includes a generally flat top surface that lies within a plane that is generally parallel with the contact surface; the one or more abrasive elements of the plurality of abrasive elements includes inwardly tapering side walls that form one or more cutting edges with the top surface; a ratio, as a percentage, of the cross-sectional area of the top surface and the cross-sectional area of a base of the abrasive element adjoining the contact surface is between 30% and 60 in some embodiments and is between 48%-52% in other embodiments; the one or more abrasive element includes a base section adjoining the contact surface and a top section adjoining the base section, wherein the top section has side walls that adjoin the top surface at the cutting edges and form an angle therebetween that is less than or equal to 90 degrees; the transition between the base section and the top section for one or more of the abrasive elements is about 0.0005 inches (0.0127 millimeters) to about 0.002 inches (0.0508 millimeters) from the top surface.

Additional or alternatively, the contact surface in some embodiments further includes a central area absent of abrasive. In accordance with some embodiments of the present disclosure, the workpiece may additionally or alternatively include a damping device. The damping device can be carried by the movable base portion and configured to damp the motion of the workpiece when oscillated by the drive system. In some embodiments, the damping device is discrete from the disc plate. In some of these embodiments, the movable base portion defines an interior cavity within which the damping device is disposed. In one embodiment, the movable base portion includes a central boss extending into the interior cavity onto which the damping device is mounted.

In accordance with some embodiments of the present disclosure, the workpiece may additionally or alternatively include means for damping the motion of the workpiece and for tuning the drive system, wherein said means is carried by the movable base portion and is separate from the disc plate.

In some embodiments of the present disclosure, the damping device or means for damping includes a flexible member. The flexible member can include or be characterized by one or more of the following features, in any combination: the flexible member has a durometer value between 10 Shore A and 100 Shore A; the flexible member includes an elastomeric material having a durometer value between 10 Shore A and 100 Shore A; the flexible member includes a central section and a plurality of vanes extending therefrom; the flexible member includes a sheet from which a plurality of spaced apart protuberances outwardly extend; and the flexible member is symmetrical along the X and Y axes.

In accordance with another aspect of the present disclosure, an exfoliating system is provided. The exfoliating system includes an appliance having a drive motor configured to oscillate a drive shaft and a brush-less exfoliating head selectively attached to the appliance. The brush-less exfoliating head in some embodiments includes a movable portion operatively coupled to the drive shaft for oscillating with the drive shaft in response to the drive motor. The movable portion includes an outwardly facing, generally planar contact surface having a plurality of abrasive elements thereon. Each abrasive element is configured to exfoliate an epidermis when placed in contact therewith. In some embodiments, each abrasive element is configured to exfoliate a partially keratinized area of the epidermis when placed in contact therewith.

In some embodiments, the one or more abrasive elements can be characterized by one or more of the following features, in any combination: the one or more of the abrasive elements extend outwardly from the surface to a height of 0.003 inches (0.0762 millimeters) to about 0.008 inches (0.203 millimeters); the one or more of the abrasive elements includes a generally flat top surface that lies within a plane that is generally parallel with the outwardly facing contact surface; and a ratio, as a percentage, of the cross-sectional area of the top surface and the cross-sectional area at a base of the abrasive element adjoining the contact surface is between 30% and 60%.

Additionally or alternatively, the drive motor and the drive shaft in some embodiments are configured to oscillate the movable portion at frequencies of about 100-190 Hz and with amplitudes of about 12-18 degrees. In some embodiments, the drive motor and the drive shaft are configured to oscillate the movable portion at frequencies of about 168-178 Hz and with amplitudes of about 12-18 degrees.

In accordance with another aspect of the present disclosure, a method is provided for exfoliating skin from a subject's epidermis. The method includes oscillating, via a motorized drive system, an exfoliating head having an outer surface with abrasive elements thereon. The abrasive elements are configured to exfoliate partially keratinized areas of the subject's epidermis. The method also includes applying the abrasive elements against a portion of the subject's epidermis. In some embodiments, the method also includes moving the exfoliating head over sections of the subject's epidermis as the abrasive elements are applied against the subject's epidermis.

In some embodiments, oscillating an exfoliating head includes oscillating the exfoliating head through a selected angle in the range of 12-18 degrees at a selected frequency in the range of 100-190 Hz. In other embodiments, the range of the selected frequency is 168-178 Hz.

Additionally or alternatively, applying the abrasive elements in some embodiments includes applying the abrasive elements against the partially keratinized area of the subject's epidermis.

In accordance with another aspect of the present disclosure, a workpiece is provided. The workpiece includes a body having a top section and a bottom section, wherein the bottom section is configured to be coupled to an oscillating drive motor, a treatment applicator, which in some embodiments is an exfoliating disc, comprising an abrasive, and a damping device carried by the body and configured to damp the motion of the body as oscillated by the oscillating drive motor. The damping device can be discrete from the treatment applicator. In some embodiments, the abrasive is configured to exfoliate a partially keratinized area of an epidermis when placed in contact therewith.

In some embodiments, the abrasive includes a plurality of abrasive elements. The one or more abrasive elements in some embodiments can be characterized by one or more of the following features, in any combination: one or more abrasive elements of the plurality of abrasive elements extends outwardly from the contact surface to a height of 0.003 inches (0.0762 millimeters) to about 0.008 inches (0.203 millimeters); one or more abrasive elements of the plurality of abrasive elements includes a generally flat top surface that lies within a plane that is generally parallel with the contact surface, and inwardly tapering side walls that form one or more cutting edges with the top surface; and a ratio, as a percentage, of the cross-sectional area of the top surface and the cross- sectional area of a base of the abrasive element adjoining the contact surface is between 30% and 60%.

Additionally or alternatively, the body in some embodiments defines an interior cavity disposed between the top section and the bottom section. The damping device is disposed within the interior cavity. In some additional embodiments, the body includes a central boss extending into the interior cavity onto which the damping device is mounted.

In some embodiments of the present disclosure, the damping device includes a flexible member. The flexible member can include or be characterized by one or more of the following features, in any combination: the flexible member has a durometer value between 10 Shore A and 100 Shore A; the flexible member includes an elastomeric material having a durometer value between 10 Shore A and 100 Shore A; the flexible member includes a central section and a plurality of vanes extending therefrom; the flexible member includes a sheet from which a plurality of spaced apart protuberances outwardly extend; and the flexible member is symmetrical along the X and Y axes.

In accordance with yet another aspect of the present disclosure, a powered skin care device is provided. The device includes a powered handle having an oscillating motor system, and a workpiece mounted to the powered handle and configured to be moved by the oscillating motor system at resonance or near resonance. In some embodiments, the workpiece includes a body having a top section and a bottom section, the bottom section configured to be coupled to an oscillating motor system, a treatment applicator disposed on the top section and comprising an abrasive, and means for damping the motion of the workpiece and for tuning the oscillating motor system. In some embodiments, said means is carried by the body and is separate from the treatment applicator.

In some embodiments of the present disclosure, the means for damping includes a flexible member. The flexible member can include or be characterized by one or more of the following features, in any combination: the flexible member has a durometer value between 10 Shore A and 100 Shore A; the flexible member includes an elastomeric material having a durometer value between 10 Shore A and 100 Shore A; the flexible member includes a central section and a plurality of vanes extending therefrom; the flexible member includes a sheet of elastomeric material from which a plurality of protuberances project; and the flexible member is symmetrical along the X and Y axes.

Additionally or alternatively, the body in some embodiments defines an interior cavity disposed between the top section and the bottom section and a central boss extending into the interior cavity. In some embodiments, said means is disposed within the interior cavity and mounted to the central boss.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of the disclosed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of one example of a workpiece, such as an exfoliating head, in accordance with aspects of the present disclosure;

FIGURE 2 is an exploded view of the exfoliating head of FIGURE 1;

FIGURE 3 is a top view of an exfoliating head, such as the exfoliating head of FIGURE 1;

FIGURE 4 is a cross-sectional view of the exfoliating head of FIGURE 1 adapted to be coupled to components of a drive motor system;

FIGURE 5 is a partial side view of one example of a surface having abrasive elements thereon in accordance with aspects of the present disclosure;

FIGURE 6 is a partial side view of another example of a surface having abrasive elements thereon in accordance with aspects of the present disclosure;

FIGURE 7 is a partial side view of another example of a surface having abrasive elements thereon in accordance with aspects of the present disclosure; FIGURE 8 is a perspective view of one example of a personal care appliance on which an exfoliating head of FIGURE 1 is mounted;

FIGURE 9 is a side view of a personal care appliance of FIGURE 8 with the exfoliating head exploded therefrom;

FIGURE 10 is a functional block diagram of several components of the personal care appliance of FIGURE 8;

FIGURE 11 is an exploded view of another example of a workpiece, such as an exfoliating head, having a damping device in accordance with aspects of the present disclosure;

FIGURE 12 is perspective view of the workpiece of FIGURE 11 without the exfoliating disc;

FIGURE 13 is a perspective view of one example of a damping device for use in the workpiece of FIGURE 11 ;

FIGURE 14 is a perspective view of one example of a damping device for use in the workpiece of FIGURE 11 ; and

FIGURE 15 is a perspective view of one example of a damping device for use in the workpiece of FIGURE 11.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings where like numerals reference like elements is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.

The following discussion provides examples of systems, apparatuses, and/or methods for treating skin. In the examples described herein, workpieces are provided that are suitable for use with a personal care appliance. In some examples described herein, the personal care appliance oscillates the workpiece in order to treat areas, such as skin, of a subject. In these and other embodiments, the workpiece includes a treatment applicator that provides improved smoothing and exfoliation of a subject's epidermis with or without the antecedent application of skin care formula. As will be described in more detail below, the oscillating action of the workpiece may be rotational (e.g., angular), translational, or a combination thereof. In some embodiments, techniques for damping the motion of the workpiece are provided. In these and other examples, techniques for tuning the oscillating motor assembly that drives the workpiece are provided.

In use, the personal care appliance oscillates the workpiece, such as an exfoliating head, over a subject's skin in order to remove dead skin from the subject's epidermis. In some embodiments, the exfoliating head is used to treat rough skin conditions, such as calluses or corns, which have developed on a patient's hand or foot. For example, the exfoliating head enables the user to sculpt a rough skin condition into a smooth, polished epidermal surface.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that many embodiments of the present disclosure may be practiced without some or all of the specific details. In some instances, well-known process steps have not been described in detail in order not to unnecessarily obscure various aspects of the present disclosure. Further, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein.

Turning now to FIGURE 1, there is shown one example of a workpiece in the form of an exfoliating head, generally designated 20, formed in accordance with aspects of the present disclosure. The head 20 is suitable for use with a personal care appliance, such as appliance 22, illustrated in FIGURES 8 and 9. As will be described in more detail below, the head 20 includes a surface 58 with abrasive sections 60 that can be oscillated over a subject's skin in order to remove dead skin cells from the epidermis. As will be also described in more detail below, some embodiments utilize sonic motion for oscillating the head 20, which can provide improved control and precision for sculpting and callus removal. As will be further described in detail below, such sonic motion can damped and/or tuned, depending on its intended application.

Prior to describing the head 20 in more detail, one example of a personal care appliance 22 that may be employed to impart an oscillating motion to the head 20 will be described in some detail. While the personal care appliance 22 is one type of appliance that can be practiced with embodiments of the present disclosure, it will be appreciated that the head 20 is suitable for use with a wide range of oscillatory or vibratory motion generating devices.

Turning now to FIGURES 8 and 9, there is shown one example of the personal care appliance 22. The appliance 22 includes a body 24 having a handle portion 26 and a head attachment portion 28. The head attachment portion 28 is configured to selectively attach a head, such as exfoliating head 20, to the appliance 22. The appliance body 24 houses the operating structure of the appliance. As shown in block diagrammatic form in FIGURE 10, the operating structure in one embodiment includes a drive motor assembly 30, a power storage source 32, such as a rechargeable battery, and a drive control 34 that includes an on/off button 36 (see FIGURE 8) configured and arranged to selectively deliver power from the power storage source 32 to the drive motor assembly 30. In some embodiments, the drive control 34 may also include a power adjust or mode control buttons 38 (see FIGURE 8) coupled to control circuitry, such as a programmed microcontroller or processor, which is configured to control the delivery of power to the drive motor assembly 30. The drive motor assembly 30 in some embodiments includes an electric drive motor 40 that drives an attached head, such as exfoliating head 20, via a drive shaft or armature 42.

When a workpiece, such as exfoliating head 20, is mounted to the head attachment portion 28, the drive motor assembly 30 is configured to impart motion to the head 20. The drive motor assembly 30 may be configured to operate the exfoliating head 20 at sonic frequencies, typically in the range of 90-300 Hz, oscillating the exfoliating head 20 back and forth within an angular range of 8-26 degrees, among others. In some embodiments, as will be described in more detail below, the exfoliating head 20 is operated at frequencies between about 100 Hz to 190 Hz with an amplitude or range of about 12-18 degrees. In other embodiments, the exfoliating head 20 is operated at frequencies of about 168 Hz to 178 Hz, amplitudes of about 12-18 degrees, and a duty cycle of about 36-48%.

One example of a drive motor assembly 30 that may be employed by the appliance 22 to oscillate the exfoliating head 20 is shown and described in U.S. Patent No. 7,786,626. However, it should be understood that this is merely an example of the structure and operation of one such appliance and that the structure, operation frequency and oscillation amplitude of such an appliance could be varied, depending in part on its intended application and/or characteristics of the exfoliating head, such as its inertial properties, etc. In some embodiments of the present disclosure, the frequency ranges are selected so as to drive the attached head at near resonance. Thus, selected frequency ranges are dependent, in part, on the inertial properties of the attached head. It will be appreciated that driving the attached head at near resonance provides many benefits, including the ability to drive the attached head at suitable amplitudes in loaded conditions (e.g., when contacting the skin). For a more detailed discussion on the design parameters of one example of the appliance, please see U.S. Patent No. 7,786,626.

Turning now to FIGURES 2-4, one example of the exfoliating head 20 will be described in more detail. As best shown in FIGURES 2 and 4, the head 20 includes a generally cylindrical, movable central portion 44. The movable central portion 44 includes a base section 48 configured to interface directly or indirectly (e.g., via drive boss 50) with the drive shaft or armature 42 of the drive motor assembly 30 at a first or inner end 52. The base section 48 is shown in FIGURE 4 as being constructed out of plastic, such as nylon, polyurethane, polypropylene, polyethylene, etc., although other materials may be utilized, including lightweight metals, such as aluminum, titanium, etc.

The movable central portion 44 further includes a disc plate 54 fixedly attached to the base section 48 at an opposite, second or outer end 56. In the embodiment shown, the disc plate 54 forms the outwardly facing surface 58 of the head 20 having one or more abrasive sections 60. The disc plate 54 is shown in FIGURE 3 as being constructed out of metal, such as stainless steel, silver, zinc, brass, copper, aluminum, gold, etc., their alloys, and combinations thereof, although other materials may be utilized, including plastics such as nylon, polyurethane, polypropylene, polyethylene, etc. In some embodiments, the disc plate 54 may include an inner core constructed from a more economical or lighter metal, such as aluminum or stainless steel, and an outer layer constructed from a more biocompatible metal, such as zinc, copper, gold or silver.

In the embodiment shown in FIGURES 2 and 4, the base section 48 includes an open-ended cavity 62 defined by a peripherally extending outer rim 64 in conjunction with shoulder or step section 66. Disposed in the center of the cavity 62 is a central boss 68 having a top support surface 70 that is generally co-planar with the support surface 72 of step section 66. To fixedly secure the disc plate 54 to the base section 48 in one embodiment, the disc plate 54 is first placed on and supported by the boss 70 and shoulder 66. The rim 64 is then die formed in order to trap the disc plate 54 between the shoulder 66 and a die-formed flange 74. In some embodiments, the die-formed flange 74 extends over and into engagement with a portion of the abrasive sections 60. It will be appreciated that other securement methods can be employed. For example, the disc plate 54 can be adhesive bonded to the base section 48.

While examples of the movable central portion 44 were shown and described as being a separate base section 48 and disc plate 54, other configurations of the central portion 44 are contemplated by the present disclosure. For example, in some embodiments, the central portion 44 can be a unitary member of metal or plastic, and can be formed by casting, molding, co-molding, or other conventional techniques.

In some embodiments, the base section 48 may also include one or more additional features. For example, the exfoliating head 20 can be specifically engineered for use in a resonant system. In this regard, it may be important to try to maintain the inertial properties of head 20 during operation. Accordingly, one or more drain holes or slots 76 may be provided around the perimeter of inner cavity 72 in order to remove any fluid and/or solids that may access the inner cavity 72. It will be appreciated that when the head 20 is designed for use with sonic motion generators, the system (e.g., drive motor assembly 30 and head 20) can be designed to stall if excessive or harmful exfoliating pressure is applied. Further, as will be further described in more detail below with regard to the embodiment of FIGURE 11, such oscillating motion can damped and/or tuned, depending on its intended application.

Returning to FIGURE 2-4, the head 20 in some embodiments includes an optional outer retainer 78. The outer retainer 78 includes a central, cylindrically shaped opening 80. The opening 80 is sized and configured to surround the sides of the movable central portion 44. When attached to the appliance 22, a rim 82, which extends around the top periphery of the central opening 80, is flush with or positioned slightly below or inwardly (i.e., toward the head attachment portion 28) of the outer surface 58 of the movable central portion 44.

In some embodiments, the central portion 44 and the outer retainer 78 together include an attachment system configured to provide selective attachment of the head 20 to the head attachment portion 28 of the personal care appliance 22. When attached to the personal care appliance 22 by the attachment system, the following occurs: (1) the movable central portion 44 is operatively connected to the drive motor assembly 30, for example, via a drive boss 50, in a manner that provides oscillating motion thereto; and (2) the outer retainer 78 fixedly secures the head 20 to the appliance 22. Accordingly, the attachment system in some embodiments provides a quick and easy technique for attaching and detaching the head 20 to the personal care appliance 22. It will be appreciated that the attachment system also allows for other personal care heads to be attached to the handle, and allows for replacement exfoliating heads to be attached to the appliance 22, when desired.

One attachment system that may be practiced with embodiments of the present disclosure is set forth in U.S. Patent No. 7,386,906. It will be appreciated that other attachment systems can be employed to provide either tooled or tool-less techniques for selectively attaching the head 20 to a personal care appliance, such as appliance 22, in a manner that (1) provides oscillating motion to the central portion 44; and (2) maintains the connection between the central portion 44 and the drive motor assembly 30. For example, in some embodiments, the central portion 44 includes a coupling interface configured to cooperatingly connect to an oscillating drive shaft or armature, such as armature 42, of an associated drive motor assembly 30 in a manner that transmits oscillating motion to the central portion 44 while fixedly securing the central portion 44 thereto. As such, it should be understood that while the retainer 78 may provide certain benefits to some embodiments of the head 20, it is optional, and thus, it may be omitted, if desired.

Referring now to FIGURES 3 and 5-7, aspects of the surface 58 having abrasive sections 60 thereon will now be described in more detail. As shown in FIGURE 5, the abrasive sections 60 of the outwardly facing surface 58 include a plurality of spaced apart, abrasive elements 84 sufficiently configured to exfoliate dead skin of a subject's epidermis. In that regard, the abrasive elements 84 may be also be referred to herein as exfoliating projections 84. As will be explained in more detail below, the abrasive elements 84 can have many configurations, depending in part on its intended application.

In some embodiments, the plurality of abrasive elements 84 are configured to provide generalized dead skin removal in areas of the body, such as the hand, elbow, or foot. In other embodiments, the plurality of abrasive elements are configured to provide for more aggressive engagement with the skin in order to sculpt and/or smooth rough areas of the body, such as the hands or feet, where calluses, corns, etc., have developed. In embodiments of the present disclosure, the abrasive elements 84 do not include bristles. As such, exfoliating heads in these embodiments can be referred to as brush-less exfoliating heads. Each of the abrasive elements 84 can have the same or similar configuration across the surface 58. Alternatively, the configurations of the abrasive elements 84 may vary throughout the surface 58 or between abrasive sections 60. As will be described in more detail below, the abrasive elements 84 in some embodiments project outwardly from the surface 58 of the disc plate 56 to a height in a range of about 0.003 inches (0.0762 millimeters) to about 0.008 inches (0.203 millimeters). In some embodiments, the disc plate includes up to 2200 abrasive elements per square inch over one or more sections of the surface 58.

It will be appreciated that in some embodiments, the abrasive elements 84 can be arranged in random fashion while in other embodiments the abrasive elements 84 can be arranged in one or more patterns. In these embodiments, the one or more patterns can be constant throughout the majority of the surface 58 or can vary throughout the minority or majority of the surface 58 or parts thereof. In the embodiment shown, the surface includes a section 86 located at the center thereof that is absent of any abrasive elements 84, although other configurations can be employed. In some embodiments, the section 86 has a smooth surface in order to aid in the prevention of premature stalling of the central portion 44 when traversing over curved surfaces of a subject and the like. In these embodiments, the smooth surface of section 86 occupies about 10% or more of the surface 58.

In accordance with some aspects of the present disclosure, the abrasive elements 84 can be embedded, adhered, attached, formed, disposed or otherwise provided on the outwardly facing surface 58 via an additive process. In some embodiments, the abrasive elements 84 are comprised of small abrasive particles including, but not limited to, diamond chips or diamond dust, silicon carbide, aluminum oxide, sand, such as silica, calcium carbonate, etc., alumina-zirconium, pumice, and combinations thereof. In some embodiments, the average diameter of the abrasive particles is in the range of about 45 microns to about 250 microns, or greater.

In one of the more simple examples of an additive process that can be employed to form the abrasive elements 84, sandpaper or the like, having grit of between 60-300, can be adhesive bonded to the surface 58 of the disk plate 54. Another additive process that may be employed in some embodiments is plating or coating. For example, in embodiments where the disc plate 54 is made of metal, a layer of metal such as nickel, silver, gold, titanium, zirconium, chromium, and/or their oxides, dioxides, etc., having a slurry of abrasive particles disposed therein can be plated to the disc plate 54 using electro or electro-less plating methods, vacuum deposition techniques, such as chemical vapor deposition, physical vapor deposition, etc., sputtering deposition, cathodic arc deposition, plasma deposition, among others.

In embodiments where the disc is made of plastic, the abrasive elements 84 can be secured thereto, for example, by first creating a thin base layer of, for example, silver or gold, using vacuum deposition techniques. Once the base layer is applied to the disc plate 54, a layer of metal such as nickel, silver, gold, titanium, zirconium, chromium, and/or their oxides, dioxides, etc., having a slurry of abrasive particles disposed therein can be plated to the base layer using an electro or electro-less plating method. In addition to electro or electro-less plating, other techniques could be used to secure the abrasive particles to a plastic disc plate, such as by using adhesive bonding or plasma deposition, among others. In other embodiments, the disc plate 54 can be co-molded with a plastic resin having abrasive particles disposed therewith.

In accordance with other aspects of the present disclosure, the abrasive elements 84 can be also formed or otherwise provided on the outwardly facing surface 58 via a subtractive process. In some embodiments, a pulsed laser deposition process may be employed. In other embodiments, the abrasive elements 84 are chemically etched into the surface 58 of the disc plate 54. In this regard, in some embodiments, the disc plate 54 is photo-etched according to a predetermined pattern and etching protocol to form the exfoliating projections on the surface of the disc plate 54.

FIGURE 5 is a partial, magnified view of the geometry of one example of the abrasive elements 84 formed by an etching process in accordance with aspects of the present disclosure. As best shown in the side view of FIGURE 5, the abrasive elements 84 are generally frusto-conical in shape, having a generally flat top surface 90 that generally define cutting edges 94. The diameter Dl of the top surface 90 is about 30%-60% of the diameter D2 of the base of the abrasive element 84 in some embodiments, and about 48-52% in other embodiments. In various embodiments, the diameter Dl of the top surface 90 is in the range of 0.004 inches (0.0102 millimeters) to 0.008 inches (0.203 millimeters). While shown and described as being generally-frusto-conical, the abrasive elements may have other inwardly tapered and truncated geometries, such as a truncated pyramid (e.g., frusto-pyramidal, etc.). Other characteristics of the abrasive elements 84 include projection heights H of approximately 0.004 inches (0.0102 millimeters) to 0.008 inches (0.203 millimeters) in some embodiments, and heights H of about 0.006 inches (0.152 millimeters) and 0.008 inches (0.203 millimeters) in other embodiments. In some embodiments, the disc plate 54 can be somewhat over-etched, thereby creating generally concave side walls 92 or portions thereof, as best shown in the example of FIGURE 6. In other embodiments, a more pronounced top or cutting edge 94 of the top surface 90 can be formed, as best shown in FIGURE 7. In this embodiment, the side walls of the abrasive elements 84 include a generally frusto-conical base section 96 and a generally cylindrical top section 98. In some embodiments, the side walls transition (designated "T") from the base section 96 to the top section 98 from about 0.0005 inches (0.0127 millimeters) to 0.002 inches (0.0508 millimeters) from the top surface 90. In some embodiments, the angle a created between the side walls of the top section 98 and the top surface 90 is preferably no more than 90 degrees.

The aforementioned geometry of one or more embodiments of the abrasive elements can be formed by an etching process. However, it will be appreciated that abrasive elements having one or more of these characteristics can be achieved with other methods of manufacture, including both additive and subtractive processes described herein. Moreover, a thin film (e.g., 0.0001 inches (0.00254 millimeters)) of titanium dioxides, zirconium dioxides, chromium dioxides, gold, silver, copper, zinc, etc., can be coated onto the abrasive elements 80 via conventional coating techniques in order to improve lubricity and/or biocompatibility of the abrasive surface, if desired.

FIGURE 11 depicts another embodiment of a workpiece, such as an exfoliating head 120, formed in accordance with aspects of the present disclosure. The exfoliating head 120 is substantially similar in construction, materials and operation as the exfoliating head 20 described above except for the differences that will now be described.

As was described above, several embodiments employ an oscillating drive motor assembly to impart an oscillating motion to the head 20. In that regard, the drive motor assembly, such as drive motor assembly 30, may be configured to operate the exfoliating head 20 at sonic frequencies, typically in the range of 90-300 Hz, oscillating the exfoliating head 20 back and forth within an angular range, for example, of 8-26 degrees.

In this system, the exfoliating head 20 can be classified as a "high Q" treatment applicator or workpiece. As a result, when operating at the above-referenced frequencies at resonance or near resonance, undesired workpiece motions can exist. In particular, parasitic motion of the head 20, such as non-concentric (i.e., wobble) planar motion and/or non-planar bending motions (e.g., motions that are not in the primary oscillating plane of the head 20, which can be, for example, co-planar with the disc plate in some embodiments), may be present when driven by the drive motor assembly 30. As will be described in more detail below, techniques for damping the potential unwanted motions of the head 20, and to allow tuning of the oscillating motor systems of near resonant personal care appliances, such as drive motor assembly 30, is provided.

In that regard, and in accordance with aspects of the present disclosure, the exfoliating head 120 of FIGURE 11 includes a damping device 180 that provides a means for damping the motion of the head 120 when operated at resonance or near resonance. By providing the damping device 180, the oscillating motor assembly 30 can be tuned to a desired operating frequency band.

In the embodiment shown in FIGURES 11-13, the damping device 180 includes a flexible member 182 having a ring 184 from which a plurality of vanes 186 radially extend. The ring 184 defines a central bore 188, which is configured to receive the central boss 68 of central portion 44 when assembled. As a result, the damping device 180 is mounted to the boss 68, as shown in FIGURE 12. An optional webbing (not shown) may be disposed between one or more vanes 186 and extend radially outwardly from the ring 182, or may extend between a position radially outward of the ring 184 and the tip of vanes 186. In some embodiments, the flexible member 182 is symmetrical along both the X and Y axis.

The flexible member 182 in some embodiments is made from an elastomeric material. The elastomeric material may have a suitable durometer in the range between about 10 Shore A and about 100 Shore A. The flexible member 182 can be constructed by a variety of processes, including but not limited to TPE injection molding, low pressure injection molding with silicones, casting, punching from sheet elastomeric material, to name a few. In some embodiments, the vanes 186 may be constructed of metal with bending characteristics, such as spring steel, piano wire elements, etc. FIGURE 14 depicts another embodiment of a damping device 180'. It will be appreciated that the thickness, length, and width of the vanes, as well as the durometer value, of damping devices 180 and 180' can be varied in order to tune the oscillating drive motor assembly 30. FIGURE 15 is another embodiment of a damping device 280 formed in accordance with aspects of the present disclosure. The damping device 280 is suitable for use with head 120 in order to provide damping to the motion thereof and to provide tuning for the oscillating drive motor assembly 30. As shown in FIGURE 15, the damping device 280 includes a flexible sheet 282 of elastomeric material from which a plurality of ridges 284 and protuberances 286 extend outwardly therefrom. In the embodiment shown, the ridges 284 are spaced apart and extend radially outwardly from a central bore 288 of the sheet 282. In some embodiments, the protuberances 286 are grouped in a spaced apart manner in-between the ridges 284. In the embodiment shown, the sheet 282 has a generally octagonal shape, although other polygonal and non-polygonal, symmetrical shapes may be used. It will be appreciated that the dimensions (e.g., height, thickness, length, diameter, etc.) and the location of the ridges 284 and the protuberances 286 can vary, as well as the durometer value of the elastomeric material, in order to dampen the motion of the head 120 and to tune the oscillating drive motor assembly 30.

The above-described examples of the exfoliating heads 20, 120 can be used to exfoliate skin of a subject's epidermis, and in some embodiments, reduce or remove rough skin conditions caused by partially keratinized cells, such as calluses or corns. In that regard, either exfoliating head 20 or 120 is first attached to the personal care appliance 22. Next, the personal care appliance 22 is turned on and the associated exfoliating head is operated at frequencies in the range of 90-300 Hz, oscillating the exfoliating head back and forth within a range of 8-26 degrees. In some embodiments, the associated exfoliating head is operated at frequencies of about 100 Hz to 190 Hz with an amplitude or range of about 12-18 degrees. In other embodiments, the associated exfoliating head is operated at frequencies of about 168 Hz to 178 Hz, an amplitude or range of about 12-18 degrees and a duty cycle of between about 36%-48%.

Once oscillating, the abrasive surface of the exfoliating head 20, 120 is applied against and traversed over the rough areas of skin on the body, such as on the feet or hands. The oscillatory action of the abrasive surface, operated at the above amplitudes and frequencies, provides an exfoliating effect, thereby sculpting the rough areas of skin and the removal or reduction of corns, calluses, etc. In some embodiments, the system is configured such that if the user applies too much force against the skin, the system will stall. Once the areas are sculpted to the desired amount, the abrasive surface of the exfoliating head 20, 120 can be removed from the skin and the appliance 22 can be powered down. Alternatively, the appliance 22 can be powered down automatically via a programmed operation.

Thus, using examples of the exfoliating head 20, 120 as described above, in the specified frequency and amplitude ranges, in the representative process outlined above, results in improved control and precision for skin sculpting and/or callus/corn removal. Additional benefits may also be realized when exfoliating skin with the exfoliating head 20, 120. For example, since skin can be removed with each directional change of the head 20, 120 as a result of the oscillating motion imparted thereon, more skin can be removed with less force as compared to conventional rotary powered devices or manually powered devices.

The method described above can be carried-out without an attempt to soften the skin by the use of skin care formulas or soaking of the skin in warm water. However, any preparation of the skin area prior to exfoliation can be used as part of the method disclosed above.

It should be noted that for purposes of this disclosure, terminology such as "upper," "lower," "vertical," "horizontal," "fore," "aft," "inner," "outer," "inwardly," "outwardly," "front," "rear," etc., should be construed as descriptive and not limiting the scope of the claimed subject matter. Further, the use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms "connected," "coupled," and "mounted" and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings.

The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects of the present disclosure which are intended to be protected are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure, as claimed.