SAMUEL O. NYAMBI

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to cosmetic product applicators; and more particularly to such applicators in the form of brushes. 2. Description of the Prior Art

Cosmetic products, such as mascara, are typically applied to the eye lashes via a brush. Typical commercial mascara packages incorporate a small elongated cylindrical container housing a quantity of mascara and a cap for the container which includes a brush. The container generally includes a wiper installed within the neck of the bottle. The wiper has a centrally located opening having a diameter such that excess mascara is wiped from the ends of the bristles. In addition to sealing the container, the cap operates as a handle for the brush.

Typically, the brush consists of a plurality of bristles held by a twisted wire, which is in turn, held by a plastic portion of the stem anchored to the interior of the cap. Past brushes have incorporated various bristle configurations. For example, brushes with shorter bristles interspersed among longer bristles; brushes forming radially extending arms (i.e., multi-lobal brushes); brushes with bristle lengths which vary along the longitudinal length of the brush (e.g., cone, or elliptical shaped brushes); and comb-like brushes utilizing one or more rows of bristles.

These brushes are utilized in one of two ways. The mascara which is applied to the eye lashes is located either near the distal ends of the bristles or near the stem. The location of mascara within the brush is controlled in large part by the interaction between the wiper and the brush. When there is relatively little wiper/brush interaction the mascara is generally applied from near the distal ends of the bristles. One disadvantage of such brushes is that the bristles tend to progressively accumulate partially dried mascara which interferes not only with the ability of the brush to hold mascara, but also with the ability of the bristles to separate the lashes. The partially dried mascara near the ends of the bristles tends to stick to the partially dried mascara on the lashes interfering with the ability of the mascara to form a uniform film on the lashes. Furthermore, this reduced

functionality is accompanied by reduced aesthetics which is unappealing to the consumer.

When there is a relatively large interaction between the wiper and the brush, the mascara is generally applied from near the stem of the brush. One disadvantage of such brushes is they tend to be less than optimal at separating the lashes. Since the brush must be designed so that the lashes can get between the bristles down to the product located near the stem, the bristles tend to be insufficient to effectively separate eye lashes which have become clumped by mascara.

SUMMARY OF THE INVENTION In accordance with one aspect of the present invention a cosmetic product applicator is provided. The cosmetic product applicator includes a brush having a product deposition section and a lash separation section. The applicator includes an elongate stem which has a distal end and a handle attached at the opposite end of the stem. The applicator also includes a plurality of bristles extending generally radially from near the distal end of the stem to form a brush. The brush includes bristles with a relatively low average bristle density in the product deposition section as compared to the average bristle density of the lash separation section. Preferably, the brush includes bristles with an average bristle length within the product deposition section which is relatively small as compared to the average bristle length of the bristles of the lash separation section. Furthermore, the average bristle diameter of the bristles within the product deposition section is preferably relatively small as compared to the average bristle diameter of the bristles of the lash separation section. Moreover, the brush preferably has a substantially identical effective stiffness over the entire length of the brush.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with the claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which like reference numerals identify identical elements and wherein;

Figure 1 is a cross-sectional view taken along the longitudinal center line of a preferred symmetrical package incorporating a particularly preferred cosmetic applicator of the present invention;

Figure 2 is an enlarged fragmentary cross-sectional view taken along the same longitudinal center line as Figure 1 ;

Figure 3 is an enlarged fragmentary cross-sectional view taken along the longitudinal center line of the cosmetic applicator of Figure 1 diagramatically illustrating the bristles;

Figure 4 is an enlarged cross-sectional view taken along line 4 - 4 of Figure 3;

Figure 5 is an enlarged cross-sectional view taken along line 5 - 5 of Figure 3; Figure 6 is an enlarged fragmentary cross-sectional view similar to Figure

3 of an alternative preferred cosmetic applicator of the present invention diagramatically illustrating the bristles;

Figure 7 is an enlarged cross-sectional view taken along line 7 - 7 of Figure 6; Figure 8 is an enlarged cross-sectional view taken along line 8 - 8 of

Figure 6;

Figure 9 is an enlarged fragmentary cross-sectional view similar to Figure 3 of a second alternative preferred cosmetic applicator of the present invention diagramatically illustrating the bristles; Figure 10 is an enlarged cross-sectional view taken along line 10 - 10 of

Figure 9;

Figure 11 is an enlarged fragmentary cross-sectional view similar to Figure 2 of the package of Figure 1, illustrated as the brush is just beginning to be pulled through the wiper; and Figure 12 is an enlarged fragmentary cross-sectional view similar to Figure

6, illustrated as the brush is about to be completely pulled through the wiper.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the particularly preferred embodiment of Figure 1, the present invention provides a cosmetic product applicator, generally designated 20. The cosmetic product applicator 20 is preferably part of a mascara package 22; including the applicator 20 and a container 24. The cosmetic product applicator 20 of this invention is preferably utilized with cosmetic products; and more preferably, with mascara. However, the cosmetic product applicator 20 of this invention may offer advantages in the application of non-cosmetic products as well.

The illustrated container 24 includes a bottle 26 which has a generally elongated cylindrical form with a closed end 28 and an open end opposite thereto

at a neck 30. The neck 30 surrounds an opening and is provided with external threads 32. The interior of the bottle 26 forms a primary product reservoir for housing the mascara. A wiper 34 is secured within the opening of the neck 30 via a snap-fit arrangement 36; best seen in Figure 2. Exemplary alternatives (not seen) for securing the wiper 34 within the neck 30, include utilizing an adhesive, a friction fit arrangement, or molding the wiper 34 and container 26 as a single integral piece.

The wiper 34 is preferably made of a relatively resilient material; e.g., blended rubber (e.g., BUNA), or polymeric materials, especially low density polyethylene. The wiper 34 includes a centrally located orifice 38. The orifice 38 has a diameter such that the wiper 34 operates to wipe excess mascara from the cosmetic product applicator 20 as the applicator 20 is pulled therethrough. Furthermore, the cosmetic product applicator 20 of the present invention benefits from utilization with wipers 34 having orifices 38 of preferred diameters, as discussed hereinafter.

Referring to Figures 1 and 2, the applicator 20 includes a cap 40 with internal threads 42 which cooperate with the threads 32 of the neck 30 of the container 24. The cap 40 also serves as a handle for the applicator 20. The applicator 20 of this embodiment includes a plug 44 which is permanently fastened to the cap 40 via a friction fit arrangement. Alternative exemplary arrangements (not seen) for permanently attaching the plug 44 to the cap 40 include utilizing an adhesive, utilizing a snap-fit arrangement, or molding the cap 40 and the plug 44 as a single integral part. The plug 44 includes a sealing bead 46 which helps seal the cap 40 and container 24 together. Additionally, the applicator 20 of this embodiment has a stem 48 which includes a plastic part 50 cantilevered from and integrally molded with the plug 44. The stem 48 further includes a twisted wire part 52 permanently fastened to the distal end of the plastic part 50 via adhesive or other suitable means. Referring to Figure 4 and 5 a plurality of bristles 53 and 54 are held at their midpoint between each twist of wire near the distal end of the twisted wire part 52. The bristles 53 and 54 extend generally radially from the twisted wire part 52 of stem; thereby forming a brush 56. Many alternative arrangements are known in the art to be acceptable for forming a brush 56.

The bristles 53 and 54 themselves are preferably made of synthetic material, although natural fibers may be utilized. Exemplary synthetic materials include nylon, and polyester; nylon being preferred. Preferably, the bristles 53 and 54 do not have solid cross-sections. Examples of non-solid cross-section bristles

include hollow or "O", "V" or "U", "I", "H", "X", and "C ^M shaped bristles which are known in the art. Alternatively, solid cross-section bristles are preferably non- circular in cross-sectional shape. Examples include trilobal, tetralobal and pentalobal bristles which are known in the art. All of these bristles have increased surface area for better product holding capacity which is particularly beneficial in the product deposition section and exhibit improved random distribution of the tips of the bristles 53 and 54 along the circumference of the brush 56 which is particularly beneficial in the lash separation section. An alternative arrangement (not seen) for creating better random bristle 53 and 54 tip distribution is to texturize the surface of the stainless steel twisted wire part 52. Also, dual polymer bristles which include an outer layer of one material surrounding a generally harder inner core material can be utilized.

Referring to Figure 3, all of the bristles 53 near the distal end of the illustrated brush 56 are the same, relatively short, length. These same short length bristles 53 can also be seen diagramatically in Figure 4. In contrast, all of the bristles 54 near the other end of the brush 56 are of the same, relatively long, length. These same long length bristles 54 can also be seen diagramatically in Figure 5. Thus, this brush 56 includes a product deposition section wherein the bristles 53 have an average length which is short relative to the average length of bristles 54 of another, lash separation, section.

Referring to Figures 4 and 5, the bristles 53 and 54 extend generally radially from the stem 48 to give the brush 56 an overall circular cross-sectional shape. As a comparison of Figure 3 with Figure 4 illustrates, the radius of the cross-sectional shape varies along the length of the stem 48. The average radius, i.e., average bristle length, of the bristles 53 of the product deposition section is preferably, less than about 6.5 mm; and more preferably, less than about 5.0 mm. Also the average bristle length of bristles 53 of the product deposition section is preferably greater than about 2.5 mm; and more preferably, greater than about 3.0 mm. The average bristle length, of the bristles 54 of the lash separation section is preferably, less than about 9.0 mm; and more preferably, less than about 8.2 mm. Also the average bristle length of bristles 54 of the product deposition section is preferably greater than about 6.0 mm; and more preferably, greater than about 7.5 mm. Furthermore, the average length of bristles 54 in product deposition are preferably from about one-third to about two-third the average length of lash separation bristles 53.

Additionally, the illustrated brush 56 includes a transitional, cone frustrum shaped section. Although such a gradual transition from the shorter bristles 53 of

the product deposition section to the longer bristles 54 of the lash separation section is preferred, the transition may be instantaneous. Furthermore, since all of the bristles 53 or 54 of a section need not be the same length, the transitional section of this brush 56, as illustrated and described herein, can be treated as part of the product deposition section, part of the lash separation section, fractionally (e.g., half and half) part of each section, or not a part of either section.

This discussion illustrates that there may be many ways to delineate the product deposition section and the lash separation section for a given brush 56. These sections may have virtually any shape. Furthermore, the aggregate of the product deposition section and the lash separation section do not need to account for all of the bristles 53 and 54 in the brush 56. What is most important is that there be a section wherein the average length of the bristles 53 within that section is relatively small (i.e., the product deposition section) as compared to the average length of the bristles 54 in another section (i.e., the lash separation section). These sections, however, preferably extend axially along a length of the stem 48 so that there is a continuous length of bristles 53 or 54 which can simultaneously come into contact with the eye lashes. Furthermore, the aggregate of the two sections preferably account for all of the bristles 53 and 54 within the brush 56. Moreover, although the bristles 53 and 54 of each section do not need to be of identical length, the lash separation section preferably includes a length of stem 48 greater than about 1.0 mm through which the bristles 54 are the same length; more preferably this length of stem 48 is greater than about 8.5; and most preferably, greater than about 10.0 mm. Additionally, the overall length of the brush 56 is preferably from about 19 mm to about 27 mm. Furthermore, the product deposition section is preferably from about the distal one-half to about two-thirds of the brush 56 length and the lash separation section is preferably from about one-third to about one-half of the brush 56 length.

Since the product deposition section utilizes shorter bristles 53, the mascara which the wiper 34 leaves near the stem 48 of the brush 56 will be more visible and accessible in the product deposition section of the brush 56. Consequently, users will be inclined to utilize the shorter bristles 53 of the (i.e., the product deposition) section to deposit mascara on the eye lashes. The product deposition section is preferably located near the distal end of the brush 56, since users naturally tend to utilize this portion of the brush 56 for product application. The longer bristles 54 of the lash separation section are easily accessed by the eye lashes and users naturally tend to use longer bristles 54 to accomplish lash separation. Moreover, these longer bristles 54 will inevitably be wiped cleaner by

the wiper 34 than the shorter bristles 53 of the product deposition section. Thus, the accumulation of partially dried product on the ends of these longer bristles 54 - which can interfere with mascara film formation on the eye lashes - is dramatically reduced. Consequently, the shape of the brush 56 given by the relative difference in the average length of the bristles 53 and 54 provides an important visual que to the user about the functionality of the brush 56; helping to ensure its most efficient utilization.

In addition to the relative difference in average length of the bristles 53 and 54, there is also a relative difference in the average diameter of the bristles 53 and 54 between the lash separation section and the product deposition section. As illustrated in Figure 3, the transition from small diameter bristles 53 to large diameter bristles 54 is stepwise. The bristles 53 of the product deposition section which are of identical length are also of identical diameter. Likewise, the bristles 54 of the lash separation section which are of identical length are also of identical diameter. The transitional cone frustrum section has bristles 59 which, although of varying length, are of identical diameter. The average diameter of these transitional bristles 59 is between that of the product application section and the lash separation section. Thus, the diameter of the bristles 53, 54 and 59 varies in a double step arrangement. The effective diameter of the bristles 53 of the product deposition section is equal to the diameter of hollow filament nylon 6/12 bristles purchased from E. I. DuPont de Nemours & Co., Wilmington, DE., under the trade name Tynex and having a diameter of preferably from about 0.05 mm to about 0.13 mm; more preferably, from about 0.07 mm to about 0.10 mm. Similarly, the diameter of the bristles 54 of the lash separation section is equal to such Tynex bristles having a diameter of preferably from about 0.1 mm to about 0.16 mm; more preferably, from about 0.1 mm to about 0.13 mm.

The preferred arrangement of the illustrated brush 56 of Figure 3 includes hollow filament bristles 53 with a diameter of about 0.07 mm in the constant diameter part of the product deposition section, hollow filament bristles 54 with a diameter of about 0.1 mm in the constant diameter part of the lash separation section, and a mixture of about 0.07 mm and 0.1 mm diameter hollow filament bristles 59 in the cone frustrum transitional section.

The section of the brush 56 with bristles 53 of small average diameter are easier for eye lashes to penetrate; thereby contacting the mascara held between the bristles 53 near the stem 48 of the brush 56. For example, bristles 53 with sufficiently small diameter are more readily deflected by the moderate contact

pressure imposed by eye lashes. The section of the brush 56 with relatively small average diameter bristles 53 is the product deposition section. Furthermore, the section of the brush 56 with bristles 54 having the larger average diameter is the lash separation section. Just as the average diameter of the bristles 53 and 54 affects the ability of lashes to penetrate into the brush 56 and the ability of the bristles 54 to separate lashes, so does the average density of the bristles 53 and 54 within the brush. For convenience, "bristle density" is defined herein as the number of bristles 53 and 54 within a section per unit length of stem 48. The average bristle density of the product deposition section is low relative to the lash separation section of the brush 56. Thus, there is a gradient between the density of the bristles 53 of the product deposition section and the bristles 54 of the lash separation section. This bristle density gradient is easily created, for example, by altering the number of bristles 53 and 54 held within each twist of the wire stem part 52. The lower bristle density of the bristles 53 of the product deposition section permits the lashes to more easily penetrate the brush 56 to contact the mascara held between the bristles 53 near the stem 48 of the brush 56. Furthermore, the lashes are able to more easily penetrate between the bristles 53 and reach this mascara. In contrast, the more dense bristles 54 of the lash separation section interface with the lashes and cause the lashes, which may have become clumped in the product deposition section, to be combed apart.

The average bristle density of the bristles 53 within the product deposition section is preferably, from about 20 to about 45 bristles per coil; and more preferably, from about 25 to about 35 bristles per coil. The average bristle 53 density of the bristles 54 within the lash separation section is preferably, from about 35 to about 65 bristles per coil; and more preferably, from about 40 to about 60 bristles per coil. Furthermore, the brush 56 preferably includes about 16 coils per inch.

In the brush 56 of Figure 1, the density of the bristles 53 in the constant diameter part of the product deposition section is about 35 bristles per twist; the density of the bristles 54 in the constant diameter part of the lash separation section is about 65 bristles per twist; and the density of the bristles 59 of the transitional section is about 45 bristles per twist.

The relation between the average bristle density and the average bristle diameter of the product deposition section and the lash separation section preferably results in the brush 56 having a substantially identical effective stiffness over the entire length of the brush 56. In other words, the brush 56 is perceived

as having an overall constant feel. Of course, there are alternative ways to achieve this constant stiffness. For example, the bristle diameter may remain constant and the material from which the bristles 53 and 54 are made may be varied to generate bristles 53 and 54 with various stiffnesses. Alternatively, shorter bristles may be interspersed among the long bristles 54 of the lash separation section to shore up the long bristles 54; thereby effectively stiffening the long bristles 54 which contact the lashes. Although any one of these or similar alternatives, alone or in combination, may be used to adjust effective bristle stiffness, preferably varying the bristle diameter and/or the bristle density is preferred. To use the applicator 20 of the present invention, the cap 40 is rotated until the threads 42 and 32 of the cap 40 and neck 30 clear each other. Grasping the cap 40, the applicator 20 is removed axially from the container 24. Referring to Figures 11 and 12, excess mascara is wiped from the brush 56 as the brush 56 passes through the orifice 38 of the wiper 34. In particular, mascara is wiped from the distal ends of the longer, lash separation bristles 54 as seen in Figure 11. Mascara, however, is held between the bristles 53 and 54 near the stem 48 of the brush 56 which is also near the distal ends of the shorter, product deposition bristles 53 as seen in Figure 12. The average bristle length of the bristles 53 of the product deposition section is preferably greater than about 0.5 mm larger than the radius of the orifice 38; and more preferably, greater than about 1.5 mm. Additionally, the average bristle length of the bristles 54 of the lash separation section is preferably greater than about 2.0 mm larger than the radius of the orifice 38. Consequently, once removed from the container 24 mascara remains near the stem 48 of the brush 56, but near the distal ends of the bristles 53 in the product deposition section. Furthermore, once removed from the container 24, the distal ends of the bristles 54 of the lash separation section are relatively clean of mascara.

Mascara is deposited on the eye lashes by bringing the product deposition section of the brush 56 into contact with the lashes. The lashes are coated with a continuous film as they penetrate into the product deposition section of the brush 56. This eye lash penetration is efficient, due to the relatively short, flexible bristles 53 and the relatively low bristle density.

Although some lash separation is provided by the bristles 53 of the product deposition section, the mascara can tend to clump the lashes as it is deposited on the lashes from the product deposition section. As this occurs, the lashes are brought into contact with the bristles 54 of the lash separation section of the brush 56. The multitude of relatively clean, relatively stiff bristles 54 comb

apart any eye lashes that have been clumped or coated with excess product. Application of product from the product deposition section and lash separation by the lash separation secton may be repeated as necessary until the desired results are achieved. An alternative preferred brush 156 of the present invention is illustrated in

Figures 6, 7 and 8. The overall shape of this brush 156 is quite similar to the overall shape of the brush 56 of Figure 1. Since this brush 156 is more rounded, this brush 156 includes a smaller number of identical length bristles 153 and 154 in each section. Another possible way to delineate the sections results in each section having all identical length bristles 153 and 154 but each section is smaller. In either case, the brush 156 includes a (product deposition) section wherein the average length of the bristles 153 is less than the average length of the bristles 154 of another (lash separation) section. Of course, delineation of these sections should be done to enable the product deposition section and lash separation section to also have the requisite relative bristle density and relative effective bristle diameter, if possible.

Referring to Figure 7, however, shorter bristles 155 are interspersed between the longer bristles 154 of the lash separation section. These shorter bristles 155 are included when calculating average bristle density, average bristle length and average bristle diameter of the lash separation section, only if they are equal to or longer than the average bristle length of the bristles 153 of the product deposition section. Shorter than full-length bristles interspersed between longer bristles 153 are not utilized in calculating average bristle density, average bristle length and average bristle diameter of the product deposition section. Only those bristles 153 whose tips form the overall- boundaries of the product deposition section are utilized.

Like the brush 56 of Figure 1, this brush 156 includes a cone frustrum, transitional section which can be included in the product deposition section, the lash separation section, fractionally in each, or in neither. It doesn't matter how this section is treated because in all cases the bristles 153 from a section taken near the distal end of the brush 156 will have a shorter average bristle length, a lower bristle density and a lower average bristle stiffness than bristles 154 of a section including the longer bristles 154 of the brush 156.

The average bristle diameter of each group of bristles 153 and 154 held within each successive twist of wire of the wire stem part 152 is progressively larger. For example, the bristles 153 of the first twist may hold bristles of 0.06 mm diameter hollow filament bristles, the next twist might hold 75% 0.06 mm

diameter hollow filament bristles and 25% 0.07 mm diameter hollow filament bristles, the next twist might hold 50% 0.60 mm diameter hollow filament bristles and 50% 0.07 mm diameter hollow filament bristles, the next twist might hold 25% 0.06 mm diameter hollow filament bristles and 25% 0.07 mm diameter hollow filament bristles, and the next twist might hold all 0.07 mm diameter hollow filament bristles. A similar pattern might be followed down the stem 148 with a mixture of 0.07 mm and 0.1 mm diameter bristles 159 and then repeated with 0.1 mm and 0.13 mm diameter hollow filament bristles 154.

Similarly the number of bristles 153 and 154 held within each successive twist of wire of the wire part 152 is progressively greater; resulting in progressively greater bristle density along the length of the brush 156. For example, the first twist of wire of the wire part 152 could hold about thirty-two bristles 154 and each successive twist of wire could hold about two more bristles 153 and 154. A second alternative preferred brush 256 is illustrated in Figures 9 and 10.

Unlike the previously described embodiments, the bristles 253 of the product deposition section is located on the opposing side of the stem 248 from the bristles 254 of the lash separation section. Also unlike the previously described embodiments, this stem 248 does not include a twisted wire part. The stem 248 includes a large diameter plastic part 250 and a small diameter plastic part 252. The small diameter plastic part 252 of the stem 248, however, has a flat side as seen in Figure 10. A resilient plastic sleeve 257 which includes the integrally molded bristles 253 and 254 is attached by adhesive over the small diameter plastic part 252 of the stem 248. The brush 256 extending from one side of the stem 248 is made up of two longitudinal rows of identical bristles 253. These bristles 253 have a relatively short length, a relatively small diameter, and are spaced to have a relatively low bristle density; thereby forming a product deposition section. Similarly, the bristles 254 of the opposing side of the brush 256 are all identical and have a relatively long length, a relatively large diameter, and are spaced to have a relatively high bristle density; thereby forming a lash separation section. The higher bristle density is created by using three rows of bristles 254 wherein the middle row of bristles 254 is offset from the outer rows.

When the brush 256 is removed from the container 24, the wiper 34 tends to cause mascara to accumulate within the longitudinal channel 259 between the rows of bristles 253. The accumulation of mascara within this longitudinal channel 259 is aided by the flat side of the stem 248 which the round orifice 38

does not strip product from. In contrast, however, the wiper 34 strips excess mascara from the distal ends of the bristles 254 of the lash separation section.

Although particular embodiments of the present invention have been illustrated and described, modifications may be made without departing from the teachings of the present invention. Accordingly, the present invention comprises all embodiments within the scope of the appended claims.