Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Non-Provisional application Ser. No. 10/364,148 filed on Feb. 11, 2003, which is entitled TOOTHBRUSHES and which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This invention relates to toothbrushes, and more particularly to power toothbrushes. 
     BACKGROUND 
     Power toothbrushes are well known and have been on the market for years. In typical power toothbrushes, tufts of bristles on the brush head extend generally perpendicularly from the top surface of the head. The head is oscillated, rotated and/or translated in order to provide enhanced tooth cleaning capability. 
     SUMMARY 
     In one aspect, the invention features a toothbrush head that includes a support member, a resilient member extending from the support member, and a plurality of bristles or tufts of bristles extending from the support member and at least partially surrounding the resilient member. By “resilient member” we mean a unitary structure formed of a resilient material such as an elastomer or foam, the resilient member having a perimeter, when the resilient member is viewed from above (e.g., looking down the long axis of the bristles, if the bristles and resilient member are disposed perpendicular to the support member), which circumscribes an area greater than the surface area of the resilient member that will initially contact the teeth of a user of the toothbrush. By “initially contact the teeth,” we mean the surface area that will contact the teeth and/or gums prior to any significant deformation of the resilient member resulting from the application of pressure against the teeth, i.e., the area that would contact the teeth if the toothbrush were lightly touched to the teeth with the power turned off. By “unitary structure,” we mean that, if the resilient member includes a plurality of elements, such as fins, protrusions or lammelae, the elements are integrally joined to form a single structure that is mounted on the separate support member. 
     In one aspect, the resilient member may be cup-shaped. 
     The term “cup-shaped,” as used herein, refers to a shape that is generally elliptical, oval, ovoid, or circular in cross-section and that defines a central open area. The walls of the cup-shaped member may be continuous or discontinuous and may define a cylinder, cone, frustoconical shape, or other desired shape. The bottom of the central open area may be flat, concave, or any other desired shape. 
     In another aspect, the resilient member may be fan-shaped. 
     The term “fan-shaped,” as used herein, refers to a shape that is generally comprised of a central hub region and at least two protrusions, e.g., ribs, fins, or other types of protrusions, that extend substantially radially from the central hub region. The protrusions may form a helix, spiral, screw, or other pattern. The central hub region may be solid, hollow, or cup-shaped, and may be, for example, generally elliptical, oval, ovoid, or circular in cross-section. 
     In a third aspect, the resilient member is “textured.” 
     The term “textured,” as used herein, refers to a structure that has a macroscopic surface texture. For example, the textured member may be composed of a cluster of ribs, fins, columns, or other protrusions, or a combination of ribs, fins, columns, or other protrusions, that together form a unitary structure. As other examples, the texture can be imparted to the member by a manufacturing process such as injection molding, by embedding particles in the surface of the member, or by selecting a material for the member that inherently has a surface texture, e.g., an open cell foam. 
     Some implementations include one or more of the following features. 
     The toothbrush head is configured for use on a power toothbrush. The cup-shaped, fan-shaped or textured member comprises a resilient material. 
     The cup-shaped member defines an open central area having a depth of from about 2 to 5 mm. The cup-shaped member includes a side wall that is substantially continuous. The cup-shaped member includes a plurality of segments that define a discontinuous side wall. The cup-shaped member includes a generally cylindrical, conical or frustoconical side wall. 
     The toothbrush head further includes a plurality of fin members extending inwardly from an inner surface of the cup-shaped member. The fins have different lengths, heights, and/or thicknesses. At least some of the fin members converge to intersect at a central hub. The central hub has a shape selected from the group consisting of cones, inverted cones, cups and cylinders. The converging fin members increase in height with increasing radial distance from the central hub. The cup-shaped member includes a wavy edge. 
     The toothbrush head further includes one or more inner cup-shaped members disposed concentrically within an open area defined by the cup-shaped member. The cup-shaped member and inner cup-shaped members are comprised of segments that define discontinuous outer walls of the cup-shaped members. 
     At least some of the tufts have different heights. The height of the bristle tufts is greater than the height of the cup-shaped member. 
     The fan-shaped member includes a plurality of protrusions extending radially from a central hub. The central hub is generally cylindrical or conical. 
     The textured member includes a plurality of lammelae extending from a common base. The textured member includes a molded element having an integrally molded surface texture. The textured member comprises a resilient member formed of a material having a macroscopic surface texture. 
     The invention also features methods of using and making the toothbrush heads described above. 
     In some implementations, the toothbrush head provides gum massaging and stimulation in addition to cleaning. The cup-shaped member may help position the toothbrush head on each individual tooth during brushing. This positioning of the head may in turn assist the user in obtaining a proper tooth-to-tooth brushing technique, rather than using a scrubbing motion. This seating action also helps to position the bristles surrounding the cup-shaped member to more effectively access areas between the teeth and along the gumline. In addition, the cup-shaped member may help hold the toothpaste against the teeth during brushing. As a result, tooth brushing may be less messy, and the toothbrush head may be able to hold more toothpaste. Also, toothpaste may tend to be concentrated against the tooth surface, which may in turn result in improved whitening, stain removal, and cleaning. The cup-shaped member may also enhance plaque removal. In some embodiments, the cup-shaped member may be designed to enhance the foaming action of toothpaste. 
     In other implementations, the toothbrush head may provide enhanced surface cleaning by the motion of the fan-shaped or textured member, both of which provide a wiping action. The increased contact area of the member with the surface of the tooth may also provide enhanced whitening and stain removal. 
     Other features and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a portion of a power toothbrush, according to a first embodiment of the invention. 
         FIG. 1A  is similar to  FIG. 1 , with the front tufts of bristles removed to show the detail of the cup-shaped member. 
         FIG. 1B  is a side view of  FIG. 1A . 
         FIG. 2  is a perspective view of a toothbrush head according to an alternative embodiment of the invention.  FIG. 2A  is a side view of a toothbrush head similar to the one shown in  FIG. 2  with the front tufts of bristles removed to show the detail of the cup-shaped member.  FIG. 2B  is a cross-sectional view of the toothbrush head shown in  FIG. 2 , taken along the long axis of the toothbrush. 
         FIGS. 3-11  are perspective views of toothbrush heads according to various alternative embodiments of the invention, with the exception of  FIG. 7A , which shows the toothbrush head shown in  FIG. 7  with the front tufts of bristles removed to show the detail of the fan-shaped member. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a power toothbrush  10  includes a head  12  and a neck  14 . As is well known to those skilled in the art, head  12  is oscillated during brushing. An electric motor (not shown) oscillates the head through gearing, linkages, cranks, and/or other drive mechanisms as is well known. Electrical power may be supplied to the motor by rechargeable or single use (disposable) batteries. Further details as to how the head is oscillated will not be provided, as this aspect of the brush is not the focus of the invention. 
     Head  12  includes a generally circular support member  16 , and, extending from the support member  16 , a plurality of bristle tufts  18 . Although each tuft is shown as a solid mass in the drawings, the tufts are actually each made up of a great mass of individual plastic bristles. The bristles may be made of any desired polymer, e.g., nylon 6.12 or 6.10, and may have any desired diameter, e.g., 4-8 mil. The tufts are supported at their bases by the support member, and may be held in place by any desired tufting technique as is well known in the art, e.g., hot tufting or a stapling process. The tufts may also be mounted to move on the support member, as is well known in the toothbrush art. 
     Head  12  further includes a cup-shaped member  20 , which can be seen clearly in  FIG. 1A , in which some of the bristle tufts have been omitted. Cup-shaped member  20  includes a side wall  22  that defines a central open area  24 . Generally, the central open area  24  has a depth of from about 2 to 5 mm, measured from the highest point of the rim of the cup-shaped member to the lowest point of the central open area. Cup-shaped member  20  also includes a plurality of ribs  26  that extend inwardly into the open area  24 . The cup-shaped member  20  is preferably formed of a resilient material such as an elastomer, e.g., a thermoplastic elastomer. The material hardness for such structures may range from 10 to 70 Shore A, with the preferred hardness selection depending on the design and dimensions of the cup-shaped member. 
     The cup-shaped member  20  may be fixedly mounted on the toothbrush head, or may be rotatably mounted, so that the cup-shaped member  20  can spin about its long axis while the toothbrush head is oscillated. The spinning motion may be driven by the same motor that oscillates the head, as would be understood by those skilled in the art. If the cup-shaped member is fixedly mounted, it may be mounted by any conventional technique, e.g., by screwing it in place or over-molding it onto the support member. 
     As shown in  FIG. 1B , the height of bristle tufts  18  above the top surface S of support member  16  will generally be greater than the height of the cup-shaped member  20  from surface S. This height differential allows the head to contour around each tooth, enhancing the tooth-to-tooth indexing effect mentioned above. 
     There is also a height differential between the different bristle tufts. The end bristle tufts  18 A, i.e., the tufts that are adjacent the long axis of the toothbrush neck  14  when the head  12  is at rest, are taller than the side tufts  18   b . For example, the height of the cup-shaped member may be from about 5.5 to 10 mm, with the end tufts  18 A being about 20 to 30% taller than the cup-shaped member, e.g., from about 6.6 to 13 mm in height, and the side tufts  18   b  being about 5 to 15% taller than the cup-shaped member, e.g., about 5.8 to 11.5 mm in height. Making the side tufts shorter than the end tufts allows the longer tufts to reach in between the teeth, while the shorter tufts clean along the gumline. 
     Toothbrush heads according to other embodiments are shown in  FIGS. 2-10 . In each of these embodiments, the support members  116  are generally elliptical, rather than circular as shown in  FIG. 1 . The elliptical shape provides more room for additional bristle tufts, and thus these toothbrush heads further include curved, elongated interdental tufts  28 . In these embodiments, the cup-shaped member and bristle tufts are generally shorter than in the embodiment discussed above. In an elliptical head, the reduced height will tend to make the brush more comfortable and less “bulky” feeling in a user&#39;s mouth. As in the embodiment discussed above, the bristle tufts are generally taller than the cup-shaped member. As shown in  FIG. 2A , the interdental tufts  28  are also taller than the cup-shaped member, e.g., by about 30 to 40%. 
     Each of the embodiments shown in  FIGS. 2-7  includes a different type of cup-shaped member. 
     In head  112 , shown in  FIG. 2 , cup shaped member  120  includes a side wall  122 , and extending inwardly from the side wall, a plurality of ribs  30  that converge at a generally cylindrical central hub  32 . In alternate embodiments (not shown) the central hub may be conical or cup-shaped. In this design, as shown in  FIG. 2B , the ribs are at the same height as the cup at the outer perimeter, and decrease in height as they approach the center. This arrangement allows the ribs to act as “squeegees” to clean the tooth surface. The addition of the central hub adds strength to the total structure and the ribs. If this additional strength is not required for a particular design, the central hub may be omitted, and the ribs may simply intersect each other, or may stop short of intersecting. In head  212 , shown in  FIG. 3 , cup-shaped member  220  includes a side wall  222  and, extending inwardly from the side wall, a plurality of larger ribs  34  and smaller ribs  36 . The larger ribs are longer (i.e., extend further into the center), and may have a different thickness and/or height than the smaller ribs. 
     In the embodiments shown in  FIGS. 4 and 5 , the cup-shaped member is segmented, i.e., it has a discontinuous side wall that includes a plurality of arcuate segments. The segmented structure imparts flexibility to the cup-shaped member, and may allow the cup-shaped member to conform better to the tooth surface. As can be seen in  FIG. 5 , in these embodiments the segments are defined by grooves  42  that do not extend to the bottom of the cup-shaped member. As a result, the segments are connected to form a unitary structure. 
     In head  312 , shown in  FIG. 4 , cup-shaped member  320  includes a segmented side wall that includes four arcuate segments  40  having grooves  42  therebetween. Within the open center area defined by the cup-shaped member  320  are disposed two concentrically arranged smaller inner cup-shaped members  44  and  46 . These inner cup-shaped members have the same segmented structure as the outer cup-shaped member  320 . The concentric members provide a large surface area for contact with the tooth surface, which may provide improved cleaning. 
     In head  412 , shown in  FIG. 5 , cup-shaped member  420  again includes a segmented side wall comprised of four arcuate segments. In this embodiment, ribs  126  extend inwardly from the side wall, as in the embodiment shown in  FIG. 1 . 
     In the embodiment shown in  FIG. 6 , head  612  includes a cup-shaped member  620  that has a wavy fringe  54  extending above its upper edge  56 . The wavy fringe is relatively soft and flexible, so that it will lay flat when pressed against the surface of the teeth. This may allow the fringe to slide under the gums and between the teeth, providing plaque removal and gum stimulation which may reduce gingivitis. Generally, the fringe has a thickness of about 0.15 to 0.25 mm, measured at its top edge, and about 0.4 to 0.8 mm measured at its base (where the fringe joins the rim of the cup-shaped member). While four relatively large waves are shown in  FIG. 6 , if desired more waves and/or smaller waves may be used. The number and size of the waves are selected to provide desired product attributes. 
     Head  612  also differs from the designs described above in that the cup-shaped member  620  includes ribs  60  that are inclined with respect to the longitudinal axis of the cup-shaped member. 
     In the embodiment shown in  FIG. 7 , head  512  includes a fan-shaped member  520  that has a plurality of ribs  50  extending radially from an outer surface of its side wall  52  in a fan-like arrangement. In this embodiment, the side wall  52  is generally conical. Alternatively, if desired, the side wall may be cylindrical (not shown). In this embodiment, the fan-like structure of the cup-shaped member may enhance the foaming action of some toothpastes. The ribs may also act as “squeegees”, enhancing tooth-cleaning action. 
     In the embodiment shown in  FIG. 8 , head  712  includes a textured member  720  that is comprised of a plurality of lammelae  722  that extend from a common base  724  together define a unitary structure. The lammelae  722  are arranged in different directions to give a “textured” feel. In this embodiment, the lammelae define a generally circular member, and are arranged in groups that are at right angles to each other in a “woven” pattern. However, the textured member may have any desired shape and arrangement of lamellae. It is generally preferred that the lammelae be relatively closely spaced, e.g., that spaces  726  be less than about 0.75 mm wide, more preferably about 0.5 mm or less. 
     In the embodiment shown in  FIG. 9 , head  812  includes a textured member  820 . Textured member  820  includes a generally cylindrical base  822  and, extending from the base, a contact portion  824  that includes a central hub  826  and a plurality of ribs  828  extending radially from the hub. Textured member  820  may be formed of a foam, as shown, to provide a surface texture. 
     In the embodiment shown in  FIG. 10 , head  912  includes a textured member  920 , including a generally cylindrical base  922  and, extending from the base, a plurality of small nubs  924  that provide the member with a textured feel. 
     A textured feel may be provided in many ways, for example by forming a resilient member of any desired shape of a material having a macroscopic surface texture, e.g., an open celled foam, or a material having texture-imparting particles embedded in its surface. 
     Other embodiments are within the scope of the following claims. 
     For example, while the cup-shaped member is shown in the drawings as centrally-located on the toothbrush head, if desired it may be positioned off-center. In  FIGS. 2-10 , the support members  116  are generally elliptical, rather than circular as shown in  FIG. 1 .  FIG. 11  illustrates a generally elliptical head  116  having cup-shaped member  320 , which is positioned off-center of the elliptical head. The remaining elements are substantially the same as the similarly identified elements described with reference to  FIG. 4 . 
     Moreover, while various embodiments are shown in the drawings and described above, many other types of cup-shaped members may be used, as will be well understood by those skilled in the art. For example, the side wall of the cup-shaped member may have a tapered outer surface, or may be straight sided or have any other desired design. 
     Additionally, which the cup-shaped member is described above as being surrounded on all sides by bristle tufts, if desired the cup-shaped member may be only partially surrounded by bristle tufts. For example, if desired the side tufts  18 B in  FIG. 1  could be omitted 
     Moreover, while heads for power toothbrushes have been described above, resilient members having the features described above may be used on manual toothbrushes, if desired.

Technology Category: 1