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Title:
BRUSHHEAD FOR SKIN BRUSH APPLIANCE
Document Type and Number:
WIPO Patent Application WO/2014/207503
Kind Code:
A1
Abstract:
Brush heads configured and arranged such that rotation or oscillation of the brush heads generates beneficial tuft and/or filament movement. Some brush heads include tufts of bristles having the same characteristics (e.g., materials, diameters, heights, etc.) while other brush heads include tufts having a plurality of bristles with different characteristics (e.g., materials, diameters, heights, etc.). The characteristics may be different from tuft to tuft or within each tuft. Bristle heights may be varied by employing non-planar brush head tufted surfaces, trimming bristles to different heights, etc. As a result of these configurations and others, individual bristles as well as entire tufts or groups of tufts provide three dimensional (3D) motion to the brushes. 3D tuft and/or bristle movement may provide improved cleaning, massaging, and/or exfoliating of a subject's skin.

Inventors:
BREWER GERALD KEITH (US)
Application Number:
PCT/IB2013/002427
Publication Date:
December 31, 2014
Filing Date:
November 01, 2013
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
OREAL (FR)
International Classes:
A46B9/06; A46B13/00
Foreign References:
US20120233798A12012-09-20
EP2443958A12012-04-25
US20050278877A12005-12-22
Other References:
None
Attorney, Agent or Firm:
NEUGEBAUER, Jürgen (Bayerstrasse 71/73, Münich, DE)
Download PDF:
Claims:
CLAIMS

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A brush head comprising a plurality of tufts anchored to a brush base, each tuft comprising a plurality of bristles each having an anchored, proximal end and extending orthogonally along a Z-axis from the brush base to a free, distal end, wherein the distance between the proximal end and the distal end is Zj in a static condition and the z-axis distance between the proximal end and the distal end is Z2 when rotated or oscillated in a suitable manner, wherein each bristle is configured such that the ratio of Z¾ - Z2 to Zj is 0.03 or greater.

2. The brush head of Claim 1 , wherein the plurality of tufts includes one or more first tufts and one or more second tufts.

3. The brush head of Claim 2, wherein the distal ends of the first and second tufts are coplanar in a static condition.

4. The brush head of Claim 2, wherein the distal ends of the first and second tufts are non-coplanar in a static condition.

5. The brush head of Claim 2, wherein the bristles of the first tufts differ from the bristles of the second tufts by one or more of: bristle material, diameter, cross- sectional geometry, and bristle length.

6. The brush head of Claim 1 , wherein when rotated or oscillated in a suitable manner includes when oscillated between about 3 degrees and about 45 degrees.

7. The brush head of Claim 1 , wherein when rotated or oscillated in a suitable manner includes when oscillated between about 6 degrees and about 20.

8. The brush head of Claim 1 , wherein the distance Zj - Z2 is from about 0.005 inches (0.127 millimeters) to about 0.020 inches (5.08 millimeters).

9. The brush head of Claim 1 , wherein the length of each bristle is from about 0.20 inches (5.08 millimeters) to about 1.20 inches (30.48 millimeters).

10. The brush head of Claim 2, wherein the variation between the static heights of the first and second tufts is between about 0.040 inches (1.016 millimeters) and 0.375 inches (9.525 millimeters).

1 1. The brush head of Claim 3, wherein the brush base includes an outer surface into which the bristles are bristled, wherein the outer surface is non-planar.

12. The brush head of Claim 1 1 , wherein the non-planar outer surface is one of a curved surface or a stepped surface.

13. The brush head of Claim 4, wherein the brush base includes an outer surface into which the bristles are bristled, wherein the outer surface is planar.

14. The brush head of Claim 4, wherein the brush base includes an outer surface into which the bristles are bristled, wherein the outer surface is non-planar.

15. A brush head comprising a plurality of tufts formed by bristles of at least two different lengths anchored into a planar brush base or bristles of the same length anchored into a non-planar brush base, wherein the lengths of the bristles are in the range of between 0.20 inches (5.08 millimeters) to about 1.20 inches (30.48 millimeters).

16. The brush head of Claim 15, wherein one or more attributes of the bristles varies from tuft to tuft.

17. The brush head of. Claim 16, wherein the one or more attributes are selected from a group consisting of bristle material and bristle geometry.

18. A powered brush comprising:

a powered handle having an oscillating motor;

a brush head mounted to the powered handle and configured to be oscillated by the oscillating motor between about 6 degrees and about 20 degrees;

characterized in that

the brush head has one or more first tufts each having a plurality of bristles of strand length Lj, and

the plurality of bristles are configured such that the tips of one or more bristles deflect through a deflection arc length A when rotated or oscillated by the oscillating motor, causing the z-axis distance between the bristle tips and the brush head to vary an amount equal to Y, wherein the ratio of distance Y to bristle strand length Lj is 0.03 or greater.

19. The power brush of Claim 18, characterized in that the brush head has one or more second tufts each having a plurality of bristles of strand length L2.

20. The powered brush of Claim 19, characterized in that

the bristles of the first tufts differ from the bristles of the second tufts by one or more of: bristle material, diameter, cross-sectional geometry, and bristle length.

Description:
BRUSHHEAD FOR SKIN BRUSH APPLIANCE

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit to U.S. Application Serial No. 61/838783, filed June 24, 2013.

BACKGROUND

Power skin care brushes, such as those useful for cleansing of the facial region, are typically driven directly, such as by a drive shaft or shafts, gears and a motor. The skin brush typically includes a single brushhead, with a plurality of bristle/filament tufts, which move in unison. Some brushheads rotate 360 degrees in one direction continuously, while others oscillate through a selected angle. The higher frequency skin brushes are often referred to as sonic or sonic frequency brushes, the frequency range of such brushes being about 120-300 Hz.

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 brush head is provided. The brush head comprises a plurality of tufts anchored to a brush base, each tuft comprising a plurality of bristles each having an anchored, proximal end and extending orthogonally along a Z-axis from the brush base to a free, distal end, wherein the distance between the proximal end and the distal end is Z[ in a static condition and the z-axis distance between the proximal end and the distal end is Z 2 when rotated or oscillated in a suitable manner. In some embodiments, each bristle is configured such that the ratio of Z j - Z 2 to Z j is 0.03 or greater ((Z, - Z 2 ):Z] > 0.03).

In accordance with some embodiments, the plurality of tufts includes one or more first tufts and one or more second tufts. In some of these embodiments, the distal ends of the first and second tufts are either copJanar in a static condition or are non-coplanar in a static condition.

In accordance with some embodiments, the brush base includes either a planar or non-planer outer surface into which the bristles are bristled. In some embodiments, the non-planar outer surface is one of a curved surface or a stepped surface. In accordance with some embodiments, the bristles of the first tufts differ from the bristles of the second tufts by one or more of: bristle material, diameter, cross-sectional geometry, and bristle length.

In accordance with another aspect of the present disclosure, a brush head is provided. The brush head comprises a plurality of tufts formed by bristles of at least two different lengths anchored into a planar brush base or bristles of the same length anchored into a non-planar brush base. In some embodiments, the lengths of the bristles are in the range of between 0.20 inches (5.08 millimeters) to about 1.20 inches (30.48 millimeters). In some of these embodiments, one or more attributes of the bristles varies from tuft to tuft. In some embodiments, the one or more attributes can be selected from a group consisting of bristle material and bristle geometry.

In accordance with yet another aspect of the present disclosure, a powered brush is provided. The powered brush comprises a powered handle having an oscillating motor, a brush head mounted to the powered handle and configured to be oscillated by the oscillating motor between about 6 degrees and about 20 degrees. In some embodiments, the brush head has one or more first tufts each having a plurality of bristles of strand length L ] , and the plurality of bristles are configured such that the tips of one or more bristles deflect through a deflection arc length A when rotated or oscillated by the oscillating motor, causing the z-axis distance between the bristle tips and the brush head to vary an amount equal to Y. In some embodiments, the ratio of distance Y to bristle strand length L j is 0.03 or greater.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of this invention 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 brush head exhibiting one example of 3D motion in accordance with aspects of the present disclosure;

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

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

FIGURE 4 is a cross-sectional view of the brush head of FIGURE 1 adapted to be coupled to components of a drive motor system; FIGURE 5 is a schematic representation of a brush head body in accordance with aspects of the present disclosure;

FIGURE 6A is a cross-sectional view of the brush head body of FIGURE 5;

FIGURE 6B is the cross-sectional view of the brush head body of FIGURE 6A bristled with a plurality of tufts, the bristled brush head body configured to exhibit 3D motion;

FIGURES 7A-7C are examples of other embodiments of bristled brush head bodies that exhibit 3D motion in accordance with aspects of the present disclosure

FIGURES 8A-B is a schematic diagram depicting "3D motion" of a bristle in accordance with aspects of the present disclosure;

FIGURE 9 is a perspective view of one example of a personal care appliance on which the brush head of FIGURE 1 is mounted;

FIGURE 10 is a perspective view of the personal care appliance of FIGURE 9 with the brush head exploded therefrom;

FIGURE 1 1 illustrates the effect of filament dimensions on the force applied by a single filament operated by an oscillating motor; and

FIGURE 12 is a functional block diagram of several components of the personal care appliance of FIGURE 9.

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 and apparatuses that relate to skin care, and more particularly, to brush heads powered by a personal care appliance that provide an oscillating, and/or rotational, brushing motion for improved cleaning, massaging, of a subject's skin. In some examples, the movement of the brush heads may also perform exfoliation of dead or damaged skin.

Brush heads of the present disclosure are configured and arranged such that rotation or oscillation of the brush heads generates beneficial tuft and/or filament movement. In that regard, some brush heads include tufts of bristles, also referred to as filaments, having the same characteristics (e.g., materials, diameters, heights, etc.) while other brush heads include tufts having a plurality of bristles with different characteristics (e.g., materials, diameters, heights, etc.). The characteristics may be different from tuft to tuft or within each tuft. As will be described in more detail below, bristle heights may be varied by employing non-planar brush head tufted surfaces, trimming bristles to different heights, etc.

As a result of these configurations and others, individual bristles as well as entire tufts or groups of tufts provide three dimensional (3D) motion to the brushes. 3D tuft and/or bristle movement may provide improved cleaning, massaging, and/or exfoliating of a subject's skin. As will be described in more detail below, 3D bristle/tuft movement or "3D motion" occurs from bristle tip flexing or whipping of one or more bristles, and can be referred generally to a z-axis distance change depicted as reference letter "Y" in FIGURE 8A. Such movement is dependent, at least in part, on the location of the bristle on the brush head (e.g., radial position on the brush head), material characteristics (e.g., modulus of elasticity, weight, etc.), dimensional characteristics (e.g., size and type of cross sectional geometry, length, etc.), oscillation characteristics (e.g., frequency, amplitude, power, etc.) and the like. As such, it will be appreciated the amount or degree of 3D motion can vary widely.

Groups of bristles, including tufts of bristle, may also exhibit "3D motion" individually on a bristle by bristle basis and collectively on a tuft by tuft basis or groups of tufts by groups of tufts basis. For example, depending on the attributes of the bristles, some of which are described herein, the amount of bristle tip flexing can vary from bristle to bristle within a tuft, from tuft to tuft, and from groups of tufts to groups of tufts. In some examples, 3D motion can occur from tuft to tuft at random positions on one or more sections of the brush head. In other examples, the 3D motion occurs in one or more recurring or non-recurring patterns of tufts on one or more sections of the brush head.

As will be described in more detail below, brush heads of the present disclosure may employ tufts with the same or similar characteristics, or can combine tufts with different bristle characteristics. Embodiments of the present disclosure can alter one or more of the aforementioned characteristics of the bristles/tufts in order to achieve suitable 3D motion for various intended applications. Other embodiments of the present disclosure can alter two or more of the aforementioned characteristics of the bristles/tufts in order to achieve suitable 3D motion for various intended applications.

In some embodiments, a combination of tufts with different bristle characteristics (e.g., material type, shape, cross section, length and/or tip finish, etc.) enables one representative brush head to provide several functions. In that regard, a brush head that combines tufts with different bristle characteristics can be arranged into patterns, for example, that provide multiple beneficial features. For example, larger diameter bristles result in heavier exfoliation than smaller diameter bristles of the same material type and same length. In other embodiments, a representative brush may have tufts with taller bristles and tufts with shorter bristles. To provide a soft gentle feeling, the tufts with the taller bristles are employed. When slightly more brushing pressure is applied the shorter bristles will feel stiffer and more aggressive, better suited for more exfoliation, etc.

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. 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 brush head with 3D motion, generally designated 20, formed in accordance with aspects of the present disclosure. The brush head 20 is suitable for use with a personal care appliance, such as appliance 22, illustrated in FIGURES 9 and 10. The brush head 20 in some embodiments includes tufts having either the same or similar bristles characteristics or different bristle characteristics. In the embodiment shown, the brush head includes a first group of tufts 58 and a second group of tufts 60. In use, the brush head 20 can be rotated or oscillated over a patient's skin in order for at least some of the bristles of tufts 58 and/or tufts 60 to exhibit 3D motion for cleaning, massaging, and/or exfoliating, etc., a subject's skin. In addition, the arrangement of the group of bristles of tufts 58 and/or tufts 60 may exhibit 3D motion, independently or collectively, depending on the bristle characteristics, anchorage, etc.

Prior to describing the brush head 20 in more detail, one example of a personal care appliance 22 that may be employed to impart an oscillating motion to the brush 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 brush head 20 is suitable for use with a wide range of oscillatory or vibratory motion generating devices.

Turning now to FIGURES 9 and 10, 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 brush 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 12, 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 9) 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 9) 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 brush head 20, via a drive shaft or armature 42.

When the brush head 20 is mounted to the head attachment portion 28, the drive motor assembly 30 is configured to impart motion to the brush head 20. The drive motor assembly 30 may be configured to operate the exfoliating brush head 20 at sonic frequencies, typically in the range of 40-350 Hz, oscillating the brush head 20 back and forth within a range or amplitude of 3-45 degrees. In some embodiments, as will be described in more detail below, the brush head 20 can be operated in loaded or unloaded conditions at frequencies from about 80 Hz to about 220 Hz and with a range or amplitude of about 6 degrees to about 20 degrees. It will be appreciated that the operation frequency and oscillation amplitude imparted to the brush head 20 by the drive motor assembly 30 could be varied, depending in part on its intended application and/or characteristics of the brush head, such as its inertial properties, etc.

As will be described in more detail below, the appliance 22 can deliver a preselected amount of power or radial angular oscillation to the bristles of the brush head 20. The oscillating movement of the brush head 20 in conjunction with the characteristics of the bristles causes at least some of the bristle tips to move with "3D motion", as briefly described above. In that regard, power and/or frequency of the oscillating drive motor of the appliance 22 can produce angular displacement sufficient to force bending of at least one bristle per tuft in some embodiments, and a majority of or substantially all of the bristles per tuft in other embodiments. When this occurs, the free end or tip motion of the bristle causes an apparent z-axis distance to be foreshortened, as best shown in FIGURES 8A-8B. Thus, the bristle tip(s) assume(s) a 3D characteristic from the bending of that bristle or a group of bristles within the tuft or from tuft to tuft. Therefore, the foreshortening in the z-axis distance of a single bristle, a group of bristles within a tuft, the entire tuft of filaments, or a group of tufts, and the variations thereof, can be referred to herein as "3D motion." As described briefly above, the amount or degree of 3D motion can vary from bristle to bristle, tuft to tuft, etc., thereby providing a type of 3D motion to the brush as a whole.

Turning now to FIGURES 2-4, one example of the brush head 20 will be described in more detail. As best shown in FIGURES 2 and 4, the brush head 20 includes a movable body 44 configured to interface directly or indirectly with the drive shaft or armature 42 of the drive motor assembly 30 at a first or inner end 50. In the embodiment shown, the body has a generally cylindrical cross-section, although other geometrical cross-sections (i.e. triangular, elliptical, lobular, square, etc.) may be employed. The body 44 can be constructed out of plastic, such as nylon, polypropylene, polyurethane, polyethylene, etc., although other materials may be utilized, including lightweight metals, such as aluminum, titanium, etc.

The brush head 20 also includes a plurality of tufts 58 and 60 disposed at an opposite, second or outer end 62 of the body 48. The tufts 58 and 60 are spaced apart from one another and include a plurality (e.g., 40-180) of bristles 64 and 66, respectively. The bristles 64 extend upwardly from a brush face or outer surface 68 of the body 48. The tufts 58 and 60 can have the same height, and thus, the distal ends of the bristles can lie in the same plane (i.e., co-planer). In other embodiments, the tufts 58 and 60 can have the different heights, and thus, the distal ends of the bristles 64 and 66 lie in different planes (i.e., non-coplanar). For example, in the embodiment shown, the brush head 20 includes a group of tufts 58 having distal ends in a first plane and a group of tufts 60 having distal ends in a second, different plane.

As described briefly above, the brush head 20 may include tufts of varying heights (e.g., tufts 58 and 60 of FIGURES 2-4). In some embodiments, the variations between tuft heights can be between about 0.040 inches (1.016 millimeters) and 0.375 inches (9.525 millimeters). In some embodiments, the varying tuft heights can be realized by bristles 58' of constant lengths bristled into a non-planar outer surface 68' or 68", as depicted in the examples of FIGURES 5, 6A-6B, and 7B. For example, the non-planar outer surface 68' may have varying peaks and valleys formed by smooth curves, as best shown in FIGURES 5 and 6A, or the non-planar outer surface 68" may be stepped, as shown in FIGURE 7B. Due to the tufts having bristles of the same length bristled into a 3D geometric brush base, the bristle tips of the tufts will move in a up/down kneading or massaging action, when oscillated or rotated, thereby exhibiting a 3D motion for the brush. Of course, the non-planar base surfaces 68', 68" of representative brush heads may be employed with bristles of different lengths in order to create one or more tufts 70 with planar distal ends, as best shown in FIGURE 7C. It will be appreciated that one or more other characteristics (e.g., diameter, material, etc.) of the bristles can be altered, bristle by bristle or tuft by tuft, in these or other embodiments in order to improve 3D motion of each tuft or a group of the tufts, depending on its intended application.

In other embodiments, instead of employing a non-planar surface with bristles of constant lengths, the varying heights of the tufts 58 and 68 may be realized by a combination of a planar face or surface 68'" and bristles with different lengths, as best shown in FIGURE 7A. For example, the bristles of the bush head may be trimmed in a multi-height to feel either more aggressive or less aggressive depending on which tufts are in contact with the skin. Again, it will be appreciated that one or more other characteristics (e.g., diameter, material, etc.) can be altered in these or other embodiments in order to improve 3D motion of the each tuft or a group of tufts, depending on its intended application.

The bristles of the tufts in some embodiments of the present disclosure have a length of about 0.20 inches ((5.08 millimeters)) to about 1.2 inches (30.48 millimeters) or greater and a diameter in the range of about 0.003 inches (0.0762 millimeters) to about 0.020 inches (0.508 millimeters) or greater. The bristles can be constructed out of a variety of materials, such as polymers and co-polymers. In some embodiments, the bristles may be constructed out polybutylene terephthalate (PBT), such as DuPont™ Crastin®, polyethylene terephthalate (PET), such as DuPont™ Rynite®, nylons of differing blends, such as DuPont™ Zytrel®, polyester, a thermoplastic elastomer (TPE), coextruded elastomers, polypropylene, polyethylene, such as DuPont™ Bynel®, combinations or blends thereof, etc. In some embodiments, the bristles may have cross sections including but not limited to rectangular, diamond, hollow, rectangular, X-shape, quadralobal, etc. Additionally, the outside surface of the bristle length may be crimped or wavy or with bumps or other texturing. Further, the bristles may be treated with anti- microbial agents in some embodiments or coated or compounded with an anti-microbial material, such as silver zeolites, zinc, copper, gold, etc., or other organic additives. End finishing of one or more bristles can also be varied to provide tactile and exfoliating properties, some of which may be smooth polished end rounding, surface texturing, tapered, raw cut ends, split, or soft elastomeric, etc.

The 3D motion of a single bristle will now be described in more detail with reference to FIGURES 8A-8B. FIGURES 8A-8B depicts a single bristle at an outermost radius of an oscillating brush with 6 degrees of rotation in one direction or typically about 12 degrees overall. When an individual tuft of, for example, an oscillating brush is subjected to a rapid change in directional drive, one or more of the bristles (i.e., filaments) will bend as represented in FIGURE 8 . This results in a z-axis distance (i.e., the distance along the Z-axis) between the distal, free end or tip of the bristle and the anchored, proximal end of the bristle that varies throughout its oscillating cycle due to flexing or bending. As such, the distal tip of the bristle begins at a distance Zj from its corresponding anchored proximal end in a static or at rest condition, and as the bristle bends due to oscillation of the brush head, the z-axis distance of the distal tip of the bristle shortens to a distance Z 2 . Typically, the distance Z [ is substantially equal to the bristle's length. In other words, the difference in the z-axis distance between the bristle tip and its corresponding anchored, proximal end when oscillated as compared to a static condition of the bristle can be referred to as the foreshortened z-axis distance (Zj minus Z 2 or Delta Z), and is denoted Y in FIGURE 8A.

When the applied inertia] bending force on a tuft results from a brush oscillating about an axis, the inertial bending force will have a direct relationship of r-theta position for the tuft location on a brush base as distanced from the center of rotation of the motor drive, frequency of oscillation and deflection angle. For some brushes, the representative brush heads of the present disclosure will provide 3D motion either when the brush is fully rotational or oscillating.

In the representative brush heads of the present disclosure, the 3D motion described herein as a function of bristle length (i.e., foreshortened z-axis distance/bristle length) is approximately 0.03 or greater. For example, in embodiments of the present disclosure, the foreshortened z-axis distance Y is typically greater than 0.005 inches (0.127 millimeters) but less than about 0.08 inches (2.032 millimeters), and the bristle length is typically greater than about 0.20 inches (5.08 millimeters) but typically less than about 1.20 inches (30.48 millimeters). In other embodiments, the foreshortened z-axis distance Y is greater than about 0.08 inches (2.032 millimeters) and the bristle length is greater than about 1.20 inches (30.48 millimeters).

Examples of different bristle heights oscillated at 6 degrees and the resulting foreshortened z-axis distance Y (See FIGURE 8 A) is shown in TABLE 1. The results in TABLE 1 were arrived with the following assumptions: (1) deflection at the tip of strand is constant regardless of strand length; (2) inertial effects of resonant motion were excluded from model; (3) analysis assumes strand centerline without considering strand thickness or bending modulus; and (4) strand is fixed at base and remains perpendicular at base of strand.

TABLE 2.

FIGURE 11 illustrates the effect of bristle dimensions on the force applied by a single bristle operated by an oscillating motor. Specifically, as the diameter increases from 0.003 inches (0.762 millimeters) to 0.005 inches (1.27 millimeters), the force applied also increases. Embodiments of the present disclosure or others may provide a 3D motion to the skin as the brush head is held gently to the skin, with applied forces in the range of 80 grams to 150 grams, more typically about 1 10 grams. Traditionally, the bristle tip effects are tangential to the surface of the skin, providing a gentle stretch and compression of the epidermis.

Returning to FIGURE 2-4, the brush head 20 further includes an optional outer retainer 76. The outer retainer 76 includes a central, cylindrically shaped opening 78. The opening 78 is sized and configured to surround the sides of the movable central portion 44. When attached to the appliance 22, a rim 80, which extends around the top periphery of the central opening 78, is flush with or positioned slightly above the outwardly facing surface of the body 48.

In some embodiments, the central portion 44 and the outer retainer 76 together include an attachment system configured to provide selective attachment of the brush 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 52, in a manner that provides oscillating motion thereto; and (2) the outer retainer 76 fixedly secures the brush head 20 to the head attachment portion 28 of the appliance 22. Accordingly, the attachment system in some embodiments provides a quick and easy technique for attaching and detaching the brush 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 appliance, and allows for replacement exfoliating brush heads 20 to be attached to the appliance, when desired.

It will be appreciated that any attachment system can be employed to provide either tooled or tool-less techniques for selectively attaching the brush 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 40 thereto. As such, it should be understood that while the retainer 76 may provide certain benefits to some embodiments of the brush head 20, it is optional, and thus, it may be omitted, if desired.

The above-described examples of the brush head 20 can be used to clean, massage, and/or exfoliate a subject's skin. In that regard, any brush head herein disclosed is first attached to the personal care appliance 22. The personal care appliance 22 is then turned on and the attached brush head is operated at sonic frequencies in the range of about 40-350 Hz, oscillating the brush head back and forth within a range of about 3-45 degrees.

Once oscillating, the brush head is applied against the skin on the body, such as on the face. Once the skin is treated to the desired amount, the brush head 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.

The methods of operation described above can be carried out with or without the use of skin care formulas or washing of the skin in warm water in an attempt to soften the skin. However, any preparation of the skin area prior to treatment can be used as part of the methods disclosed above.

It should be noted that for purposes of this disclosure, terminology such as "upper," "lower," "vertical," "horizontal," "inwardly," "outwardly," "inner," "outer," "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.