Abstract:
An cosmetic applicator comprising a brush portion of relatively soft, flexible injection molded bristles, and a comb portion of relatively hard, inflexible injection molded teeth, the comb portion being assembled to the brush portion after each portion is molded. In one preferred embodiment, the comb portion has two or more columns of teeth arranged parallel to each other, which makes for a more effective comb.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention is in the field of cosmetic applicators, specifically hair product applicators with molded applicator heads. 
       BACKGROUND 
       [0002]    Cosmetic applicators are used for taking up a dose of product and applying it to an application surface, typically the hair of the head, such as eyebrows or eyelashes. Thereafter, the same cosmetic applicator is used for grooming the hair by combing and separating the individual hair fibers, smoothing the product thereon, and removing any excess product. Because the function of taking up and depositing product is different from the function of grooming the hair, a single cosmetic applicator may not perform both functions satisfactorily. For example, where relatively softer bristles are known to be good at taking up product and depositing on the eyelashes, these bristles tend to be too weak to effectively smooth the product over the lashes, breakup clumps of mascara, which is a thick heavy product, or separate the lashes. This situation has sometimes been addressed by using separate applicators for depositing product and grooming the hair. The first tends to be a brush that has softer, more flexible bristles, while the latter may be a brush or comb that has relatively stiff bristles or teeth. 
         [0003]    To avoid the inconvenience of having to use separate tools to perform the application and grooming steps, it is known to integrate a brush of less stiff bristles with a comb of stiffer teeth into a single cosmetic applicator. Various prior art references have disclosed such integrated cosmetic applicators with different arrangements and constructions. For example, U.S. Pat. No. 7,231,926 discloses a mascara applicator that comprises an application brush part and an arrangement brush part. We will discuss U.S. Pat. No. 7,231,926, which we consider to be the closest prior art. 
         [0004]    Referring to  FIGS. 1-3 , U.S. Pat. No. 7,231,926 discloses a mascara applicator comprising a grip ( 6 ), a rod ( 2 ) extending form the grip. A “fixing stand” ( 40 ) depends from the rod ( 2 ). An arrangement brush part (or comb,  4 ) is implemented as one or more columns of injection molded teeth that radiate from the fixing stand ( 40 ). An application brush part ( 3 ) may comprise an application portion ( 7 ) of bristles that radiate from a twisted wire rod ( 21 ), and occupy the space between the “fitting hole” ( 42 ) and the “fitting recess” ( 43 ). In order for the application brush part to fit into the space between the “fitting hole” and the “fitting recess”, the application brush part is provided with an angular section ( 31 ) of 30°-120° that is devoid of bristles (see  FIG. 3 ). 
         [0005]    It is clear from  FIG. 2  of U.S. Pat. No. 7,231,926, and from the description, that the distal end of the twisted wire rod (with bristles) is inserted through the fitting hole ( 42 ) until it comes to rest in the fitting recess ( 43 ). This manner of assembly gives rise to certain deficiencies. For example, the fiber bristles of the application portion ( 7 ) are not able to extend the full length of the space between the “fitting hole” ( 42 ) and the “fitting recess” ( 43 ). Rather, there is a gap (see  FIG. 1 ). The gap is required in order to ensure that none of the bristles remains stuck in the fitting hole ( 42 ). In fact, in order to avoid bristles being stuck in the fitting hole ( 42 ), the size of this gap should be at least as large as the radius of the fiber brush. For example, for a brush with an overall diameter of 8 mm, the gap should be a minimum 4 mm, and for a brush with an overall diameter of 10 mm, the gap should be a minimum of 5 mm. (We note that  FIG. 1  of U.S. Pat. No. 7,231,926 does not really reflect how big the gap would have to be to avoid this problem.) Such a big gap, however, creates a different problem, which is that there will be some amount of unwanted movement, where the application brush part ( 3 ) can slide back and forth in the arrangement brush part, which may be a distraction to the user or interfere with application process. The design of the applicator of U.S. Pat. No. 7,231,926 has other shortcomings as well, which we now discuss. 
         [0006]    The manner in which the application brush part ( 3 ) is assembled to the fixing stand ( 40 ), means that the bristles of the application portion ( 7 ) cannot extend to the distal tip of the applicator. This is a real disadvantage when trying to apply mascara to the eyelashes that are toward the inner canthus of the eye. 
         [0007]    Furthermore, in order to pass through the fitting hole ( 42 ), the bristles of the application portion ( 7 ) must be relatively flexible. Fiber bristles may be sufficiently flexible, but even that is no guarantee that the bristles will not be damaged when they are crushed together to pass through the fitting hole. On the other hand, if the bristles of the application brush part ( 3 ) are injection molded, as disclosed in one embodiment of U.S. Pat. No. 7,231,926, then they are not likely to be very flexible since they are made of the same material as the rods ( 2 ,  21 ) which provide structural support for the applicator. Therefore, it is certainly not clear how these stiff bristles would fit through the fitting hole ( 42 ) without breaking. 
         [0008]    In another matter, the need to pass the application brush part ( 3 ) through the fitting hole ( 42 ) places limitations on the application portion ( 7 ). Application portions that have thick bristles and/or a high bristle density would be more likely to be damaged, so they would be avoided.  FIG. 2  of U.S. Pat. No. 7,231,926 gives the distinct impression that the diameter of the fitting hole ( 42 ) is very nearly equal to the diameter of the twisted wire rod ( 21 ), so the bristle portion ( 7 ) is really squeezed. 
         [0009]    Also, as we noted above, the application brush part ( 3 ) is provided with an angular section ( 31 ) of 30°-120° that is devoid of bristles. Consequently, the angular size of the arrangement brush part ( 4 ) is limited to 30°-120°. 
         [0010]    Also, the teeth of the arrangement brush part ( 4 ) radiate perpendicularly from a cylindrical surface, so that the teeth in two different columns are not parallel to each other. This does not seem like the most effective arrangement to comb small portions of hair like the eyelashes. 
         [0011]    There is therefore a continuing need for improved cosmetic applicators of dual functions, i.e., which can be used for performing both the cosmetic application function and the hair/eyelash arrangement function, but without the above-described drawbacks of the prior art applicators. 
       SUMMARY OF THE INVENTION 
       [0012]    The invention concerns a molded applicator head for cosmetic applicators, as well as a cosmetic applicator that comprises the molded applicator head as disclosed herein. An applicator head for a cosmetic applicator comprises a brush portion of relatively soft, flexible injection molded bristles, and a comb portion of relatively hard, inflexible injection molded teeth, the comb portion being assembled to the brush portion after each portion is molded. The assembled applicator head has a distal end that is covered with the relatively softer bristles to facilitate applying mascara to those eyelashes that are near the inner canthus of the eye. Together, the brush portion and the comb portion fill and angular sector of 360°. The brush portion fills an angular sector of 180°-200°, while the comb portion fills an angular sector of 160°-180°, which is significantly greater than the 30°-120° of the arrangement brush portion ( 4 ) of U.S. Pat. No. 7,231,926. In one preferred embodiment, this larger comb portion allows two or more columns of teeth to be arranged parallel to each other, which makes for a more effective comb. The snap fit assembly method of the comb portion into the brush portion eliminates the need for a gap between the comb and brush portions, along with any unwanted play, so that the comb portion cannot slide back and forth with respect to the brush portion. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0013]      FIGS. 1-3  depict a prior art applicator disclosed in U.S. Pat. No. 7,231,926. 
           [0014]      FIGS. 4A and 4B  depict a mascara applicator according to the present invention. 
           [0015]      FIGS. 5A and 5B  depict one embodiment of a brush portion of an applicator head according to the present invention. 
           [0016]      FIGS. 6A and 6B  depict one embodiment of a comb portion of an applicator head according to the present invention. 
           [0017]      FIGS. 7A and 7B  depict a second embodiment of a comb portion of an applicator head according to the present invention. 
           [0018]      FIGS. 8A and 8B  show the a comb portion being assembled to a brush portion. 
           [0019]      FIGS. 9 and 10  show two embodiments of assembled applicator heads according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring to  FIGS. 4A and 4B , a mascara applicator according to the present invention comprises a handle ( 11 ), an extended rod ( 12 ), and an applicator head ( 13 ) in the usual relationship of these elements. That is, the handle serves as a closure for a container of mascara product. Typically, the closure has screw threads ( 11   a ) on its inner surface for mating to a threaded container. The extended rod is connected to and depends from an inner surface of the handle, and the applicator head depends from the distal end ( 12   a ) of the rod. For example, the rod may be hollow, and able to receive the stem ( 14   a ) of the applicator head into itself. The stem may be retained in the rod by adhesive, welding, a friction fit, snap engagement, threaded engagement or any other suitable retaining means. An applicator head according to the present invention has two main parts: the brush portion ( 14 ) and the comb portion ( 15 ). 
       The Brush Portion 
       [0021]    Referring to  FIGS. 5A and 5B , the brush portion ( 14 ) comprises a stem ( 14   a ) and a main body ( 14   f ). The stem may be formed as a generally cylindrical member having proximal ( 14   b ) and distal ( 14   c ) ends, and a hollow space ( 14   d ) that opens onto the distal end of the stem, and onto the side wall ( 14   e ) of the stem. The side wall of the stem is devoid of bristles or other grooming features, and is generally smooth, so that the stem is able to join to the distal end ( 12   a ) of the rod ( 12 ), as described above. 
         [0022]    The main body ( 14   f ) comprises an approximately semi-cylindrical member ( 14   g ), an opened proximal end ( 14   h ), and a closed distal end ( 14   i ). The semi-cylindrical member ( 14   g ) defines a hollow space ( 14   j ) that connects to the opened proximal end ( 14   h ) and to a groove ( 14   k ) located in the closed distal end ( 14   i ) of the main body (see  FIG. 8A ). The opened proximal end ( 14   h ) is integrally molded to the opened distal end ( 14   c ) of the stem ( 14   a ), such that the hollow space ( 14   j ) of the semi-cylindrical member and the hollow space ( 14   d ) of the stem are contiguous, as shown. When we say that the semi-cylindrical member ( 14   g ) is approximately semi-cylindrical, we mean that the semi-cylindrical member occupies an angular space of approximately 180°-200°. The distal end ( 14   i ) of the main body ( 14   f ) occupies a complete 360° around longitudinal axis A-A, while the proximal end ( 14   h ) may occupy between about 200° and 270°. Also, the semi-cylindrical member ( 14   g ) may taper toward the closed distal end ( 14   i ). The outside surface of the semi-cylindrical member features a multitude of bristles ( 14   l ), as does the closed distal end ( 14   i ) of the main body. The proximal end ( 14   h ) of the main body may or may not comprise bristles. 
         [0023]    Preferably, the bristles ( 14   l ) of the semi-cylindrical member ( 14   g ) are regularly arranged in columns ( 14   p ) that extend down the semi-cylindrical member, parallel to the longitudinal axis (A-A) of the main body ( 14   f ). Each column of bristles may typically comprise from 5 to 50 bristles, preferably from 10 to 40, more preferably from 20 to 35 bristles. For example, the semi-cylindrical member of  FIG. 5A  has 23 bristles in a longitudinal column. The semi-cylindrical member may preferably comprise from 4 to 10 columns of bristles. More preferred are 7, 8 or 9 columns of bristles. For example, in  FIG. 5B , the semi-cylindrical member of the main body ( 14   f ) has 9 columns of bristles extending longitudinally along the semi-cylindrical member. Furthermore, in preferred embodiments, bristles ( 14   l ) of the semi-cylindrical member are regularly arranged in rows, each row lying on a circumference of the semi-cylindrical member, in a plane that is perpendicular to the longitudinal axis of the main body. 
         [0024]    The bristles ( 14   l ) of the semi-cylindrical member ( 14   g ) of the main body ( 14   f ) typically extend radially from the longitudinal axis of the main body, and all of the bristles in a single column are parallel to each other. The bristles of the distal end ( 14   i ) of the main body extend in various directions. The bristles may comprise flat and/or rounded portions, and the horizontal cross section of the bristles may be any conceivable shape, only limited by the ability to mold the main body. Preferred, however, are bristles that have a horizontal cross section that is shaped as a circular segment that has an arc that ranges from about 160° to no more than 180°, and whose radius decreases as you move from base to tip. Such bristles have a semi-conical profile comprised of a flat face and a curved face. Preferably, the bristles would have a rounded tip. The remainder of each bristle may be shaped to have one or more depressions, one or more protrusions, or both on the curved face of the semi-conical bristle, while the flat face has no such features. Preferably, each semi-conical bristle has at least two depressions and/or protrusions located on its curved surface. The manufacture of such bristles was described in U.S. Pat. No. 9,326,590 which is hereby incorporated by reference in its entirety. Also, a bristle may have one or more perforations that pass through the bristle from the flat face to the curved face. The manufacture of such bristles was described in U.S. Pat. No. 9,326,584 which is hereby incorporated by reference in its entirety. As can be seen in  FIG. 5B  the bristles of the brush portion ( 14 ) do not have to be all the same height. 
       The Comb Portion 
       [0025]    Referring to  FIGS. 6A and 6B , the comb portion ( 15 ) comprises a base ( 15   a ) that has a proximal ( 15   b ) and a distal ( 15   c ) end. Preferably, the base is cylindrical, as shown. Integrally molded to the cylindrical base is a platform ( 15   d ) that supports a multitude of teeth ( 15   e ). The cylindrical base is longer than the platform, and the proximal and distal ends of the cylindrical base extend beyond the ends of the platform. 
         [0026]    Preferably, the teeth ( 15   e ) of the platform ( 15   d ) are regularly arranged in columns ( 15   p ) that extend down the platform, parallel to the longitudinal axis (B-B) of platform. Each column of teeth may typically comprise from 5 to 50 teeth, preferably from 10 to 40, more preferably from 20 to 35 teeth. For example, the platform of  FIG. 6A  has 24 or 25 teeth in a longitudinal column. The platform may preferably comprise from 1 to 8 columns of teeth. More preferred are 4 to 7 columns of teeth. For example, in  FIG. 6B , the platform ( 15   d ) has 7 columns of teeth extending longitudinally along the platform, while in  FIG. 7B  the number of columns of teeth is 5. Furthermore, in preferred embodiments, the teeth ( 15   e ) of the platform are regularly arranged in rows across the platform, in a plane that is perpendicular to the longitudinal axis of the platform. 
         [0027]    In  FIGS. 6A and 6B , the platform ( 15   d ) is semi-cylindrical, and occupies an angular space of approximately 160°-180°. The teeth ( 15   e ) of the platform ( 15   d ) typically extend radially from the surface of the platform, and all of the teeth in a single column are parallel to each other, while adjacent columns are oriented an angle to each other. In some embodiments of the invention, however, the platform shown in  FIGS. 7A and 7B  is preferred. Here, the platform ( 15   d ) has curved side walls ( 15   g ), and a flat portion ( 15   h ), which we may call the top of the platform. Despite its flat top, this platform also occupies an angular space of approximately 160°-180°. Because the portion ( 15   h ) of the platform is flat, all of the teeth ( 15   e ) that arise from this portion of the platform are parallel to each other, while those teeth ( 15   e ′) that are on the curved side walls extend at some other angle. The flat top surface means that rows of teeth will be parallel to each other, which makes the comb portion a much more effective comb than it otherwise would be. But this parallel arrangement of teeth would not be possible, or would be significantly more difficult and expensive to execute if the angular space occupied by the comb portion was limited to 30° to 120°, as in U.S. Pat. No. 7,231,926, which does not disclose or suggest parallel rows of teeth in the comb portion (i.e. in the arrangement brush part). There simply would not be enough space on the top of the platform to arrange multiple rows of parallel conical teeth. Preferably, an applicator head according to the present invention will have a comb section that has at least two columns of teeth that are parallel to each other, more preferred are three columns of teeth that are parallel to each other. 
         [0028]    The teeth ( 15   e ,  15   e ′) of the comb portion ( 15 ) may comprise flat and/or rounded portions, and the horizontal cross section of the teeth may be any conceivable shape, only limited by the ability to mold the main body. Preferred, however, are conical teeth that are generally free of any surface features, which provides an efficient combing action. As can be seen in  FIG. 6B  the teeth of the comb portion do not have to be all the same height. 
       The Assembled Applicator 
       [0029]    The brush and comb portions are molded separately, and subsequently assembled. Exemplary materials that can be used in the present invention to mold the brush portion ( 14 ) and/or the comb portion ( 15 ) include, but are not limited to: silicone elastomers, thermoplastic elastomers (such as, for example, styrene-ethylene-butylene-styrene block copolymer—SEBS), vinyl elastomers (EVA), thermoplastic polyester elastomers (Hytrel® from Dupont de Nemours), thermoplastic polyurethane elastomers (Pellethane® from Dow Plastic), Nitrile, and EPDM. Hardness of the chosen material preferably ranges from about 35 MPa (35 shore D Hytrel® from Dupont de Nemours) to about 1180 MPa (82 shore D Hytrel®). Harder, less flexible materials will be more suitable for the comb portion, and softer, more flexible materials will be more suitable for the brush portion. Therefore, when measured with same type of durometer, the material from which the brush portion ( 14 ) is molded will measure a hardness that is less than the material from which the comb portion ( 15 ) is molded. 
         [0030]    As noted above, the proximal ( 15   b ) and distal ( 15   c ) ends of the cylindrical base ( 15   a ) of the comb portion extend beyond the ends of the platform ( 15   d ). Referring to  FIG. 8A , the first step in assembling the comb portion ( 15 ) to the brush portion ( 14 ) is to insert the distal end ( 15   c ) of the comb portion into the groove ( 14   k ) of the brush portion. Then, as shown in  FIG. 8B , the cylindrical base ( 15   a ) is brought into the hollow space ( 14   j ) of the semi-cylindrical member ( 14   g ) of the brush portion ( 14 ), and the proximal end ( 15   b ) of the comb portion comes to rest in the hollow space ( 14   d ) of the stem ( 14   a ). Two embodiments of the fully assembled applicator head are shown in  FIGS. 9 and 10 .  FIG. 9  is an embodiment wherein the platform ( 15   d ) is semi-cylindrical.  FIG. 10  is the more preferred embodiment wherein the platform has curved side walls ( 15   g ), and a flat top ( 15   h ) that supports 3 parallel columns ( 15   p ) of teeth ( 15   e ). In order the make sure the comb portion remains in the brush portion, the hollow space ( 14   d ) of the stem ( 14   a ) may be provided with one or more flexible ( 14   m ) tabs that allow the proximal end ( 15   b ) of the comb portion ( 15 ) to be forced into the hollow space of the stem, but that prevent its accidental removal therefrom. Once the applicator head is assembled, the stem ( 14   a ) of the brush portion ( 14 ) can be secured to the distal end of a rod ( 12 ) as explained above to complete the mascara applicator. 
         [0031]    When assembled, the longitudinal axis (A-A) of the brush portion is parallel to the longitudinal axis (B-B) of the comb portion. Together, the brush portion ( 14 ) and the comb portion ( 15 ) fill and angular sector of 360°. The brush portion fills an angular sector of 180°-200°, while the comb portion fills an angular sector of 160°-180°, which is significantly greater than the 30°-120° of the arrangement brush portion ( 4 ) of U.S. Pat. No. 7,231,926. The greater angular size of the comb portion provides better grooming of the lashes, especially curling. 
         [0032]    The distal end ( 14   i ) of the assembled applicator is covered with the relatively softer bristles to facilitate applying mascara to those eyelashes that are near the inner canthus of the eye. This feature is also missing from the applicator of U.S. Pat. No. 7,231,926, which has no bristles on its distal end. 
         [0033]    Also, because of the presence of the hollow space ( 14   d ) in the side wall ( 14   e ) of the stem, we were able to make the length of the platform ( 15   d ) to be equal (within molding tolerances) to the length of the hollow space ( 14   j ) of the main body ( 14   f ), which is preferred because any gap between the brush and comb portions is then eliminated. Also, the comb portion will not be able to slide back and forth in the brush portion.