Abstract:
A metal-toothed comb is provided having elongated identical teeth each with a square cross-section along substantially the entire length, elongated edges of each tooth being slightly rounded, free ends of each of the teeth being slightly rounded, whereby the teeth are successively positioned juxtaposed in a common plane, with elongated edges of each tooth opposing one another, and the distance between the teeth being a constant 0.004 inch along the entire length of the gap therebetween, except for a relatively small portion proximate the distal ends of each tooth, which are tapered down to a rounded tip.

Description:
RELATED APPLICATION 
     The present invention is related to Provisional Application No. 61/216,862, filed on May 26, 2009, and takes priority therefrom to the extent that there is no conflict therewith. 
    
    
     FIELD OF THE INVENTION 
     The present invention is related generally to products such as combs for personal grooming of the hair, and more particularly to combs for removing lice and nits from the hair and scalp of an infected individual. 
     BACKGROUND OF THE INVENTION 
     Head lice ( Pediculus humanus capitis ) are small parasitic insects, which have evolved to live and thrive on the scalp and neck hairs of their human host. The external parasitic insects are often difficult to eradicate, and present a health problem to those afflicted. Head lice can also afflict people in developed areas such as in schools where people are in constant close contact. Those afflicted with head lice have to undergo some form of treatment or intervention for relief. The insecticide or pesticide is usually periodically applied to the hair and scalp of the afflicted individual to kill the head lice. Recently, it has been found that certain head lice strains have developed resistance against some of the more popular insecticides or pesticides currently available in the market. 
     In addition to insecticides or pesticides, mechanical means have also been employed in the treatment of head lice. Such mechanical means function by physically removing head lice and nits from the hair and scalp and can be effectively implemented alone or in combination with the insecticide or pesticide treatment. One mechanical means found to be effective is the lice and nit comb, which is a toothed instrument adapted for confining hair and sifting out the lice and nits. The typical lice and nit comb includes a plurality of spaced apart teeth arranged in a single row. The space between adjacent teeth is typically diminutive to permit the strands of hair to pass through as the comb is drawn, but prevent head lice and nits from passing through the space. In this manner, lice and nits present on the hair strands are effectively scraped off as the comb moves along the length of the hair. 
     Ideally, in order to ensure that the lice and nits are caught by the comb, the entire outer surface of the hair strands are scraped and cleaned to prevent the lice and nits from avoiding the scraping action. However, the adjacent parallel teeth of known plastic lice and nit combs have teeth of limited length, whereby the teeth are only able to scrape portions of the limited number of hair strands occupied therebetween. These limitations have made prior art lice and nit combs more time consuming and inconvenient to use, and less effective in sifting and removing lice and nits from hair. 
     Accordingly, there is a need for an improved lice and nit removal comb capable of captively and circumferentially grasping around a relatively large number of strands of hair for enhanced scraping and cleaning action to entrap and remove lice and nits present as the device is drawn along the length of the grasped hair. In this manner, any lice and/or nit present in the hair is efficiently and effectively sifted and removed therefrom with minimized effort. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a lice and nit removal comb that has rigid elongated teeth which resist bending upon use. 
     Another object of the invention is to provide a lice and nit removal comb that includes elongated teeth capable of removing lice and nits along substantially the entire length of the teeth in the spaces between successive juxtaposed teeth lying in a common plane. 
     With these and other objects in mind, the present invention includes a handle portion for permitting a user to grasp the comb, another portion for mounting rigid bend resistant metal teeth at their proximal ends in a manner for insuring that all portions of each tooth are parallel to an adjacent tooth, whereby except for the free ends of each tooth, each have a square-shaped cross-section. Each tooth, proximate their distal end portions tapers slightly to a rounded tip for preventing injury to the scalp of a user. The longitudinal corner edges of each tooth have a small radius, whereby between the successive pairs of parallel teeth, the longitudinal edges oppose one another for almost the entire length of each tooth, except for the extreme distal end portion which tapers to a rounded end. In the preferred embodiment of the invention, the space between opposing corner edges of each pair of adjacent teeth is 0.004 inch from the proximal end to their tapered distal end portions. Proximal end portions of each tooth are formed in a notched configuration for enhancing the securement of each tooth in the tooth retaining portion of the comb. A comb handle and the tooth retaining portions are preferably formed from a single piece of plastic material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the present invention are described in detail below with reference to the drawings, in which like items are identified by the same reference designation, wherein: 
         FIG. 1A  is a side view of the present comb for one embodiment of the invention having a scalloped handle portion; 
         FIG. 1B  is a pictorial view of the embodiment of  FIG. 1  looking from the back end of the handle at an angle; 
         FIG. 2  is a front elevational view of the comb of  FIG. 1 ; 
         FIG. 3  is a back elevational view of the comb of  FIG. 1 ; 
         FIG. 4  is an enlarged cutaway view of the tooth mounting portion of the comb of  FIG. 1  showing the arrangement of the proximal ends of the teeth secured therein; 
         FIG. 5  shows a cross-sectional view of the teeth of  FIG. 4  taken along  5 - 5  thereof; 
         FIG. 6  shows a bottom view of the distal ends or free ends of each tooth; 
         FIG. 7  shows a front elevational view of an alternative embodiment of the invention using a different handle configuration; 
         FIG. 8  shows a right-side elevational view of the embodiment of the invention of  FIG. 7 , the left-side elevational view being identical thereto. 
         FIG. 9A  shows an alternative embodiment to that of  FIGS. 1A ,  1 B, and  2 , wherein in this alternative the distal ends of the teeth are arranged in a curved or concave configuration; and 
         FIG. 9B  is a partial cross sectional view taken along  9 B- 9 B of  FIG. 9A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 1A , in one embodiment of the invention, the present comb  2  includes a scalloped-shaped frame or body  4  having a hand-gripping portion  6 , a tail portion  8 , and a front tooth holding portion  10  for rigidly maintaining the teeth  12 , a rounded front tip  11 , and downwardly protruding tabs  14 , as shown. The various dimensions shown, namely, L 1  through L 5  are typically a matter of choice and can be varied. In this example, 26 teeth are shown, and L 1  is about 1.563 inches for 26 teeth  12 . L 2  is about 5.500 inches, L 3  about 2.750 inches, L 4  about 0.625 inch, and L 5  about 0.375 inch. As indicated, these dimensions are approximate, and are provided for purposes of illustration. In  FIG. 1B , a pictorial is shown of the inventive comb of  FIG. 1A  looking at an angle from the back of the tail portion  8 . 
     With reference to  FIG. 2 , the length of each tooth  12 , shown as D 1 , can range from 1.500 inches to 2.720 inches. In the preferred embodiment, the length D 1  of each of the teeth  12  is 1.897 inches. Also, in this example, the minimum length of the teeth  12  protruding from the one portion  10 , shown as D 2  can range from about 1.250 inches to 1.500 inches. In the preferred embodiment, D 2  is 1.425 inches. 
       FIG. 2  is a front elevational view of the comb  2 . As shown, in this example, the handle or hand-gripping portion  6  is oval, as is front portion  10 . The tail portion  8  has a circular transverse cross section (see  FIG. 3 ). 
     With reference to  FIG. 4 , an enlarged view of four of the centermost located teeth  12  are shown as mounted in the front portion  10  of the comb  2 . As shown, proximal ends  16  of the teeth  12  include notches  17  to enhance the retention of these ends in the plastic material of the comb body  4 , in this example. In this regard, the comb body  4  can be provided by any suitable plastic material, such as ABS plastic, or polypropylene, for example. The dimension D 3  for the notched end portion  16  can range between 0.15 inch to 0.25 inch, and in the preferred embodiment is 0.1875 inch. The portion of the teeth  12  proximate to the distal end portion taper slightly converging to a rounded end  18 . The taper is preferably 1:5, but can be extended to 1:8. The tapered distal end portion  20  has a length D 4  ranging from 0.093 inch to 0.156 inch, whereby the preferred length D 4  is 0.275 inch, in this example. The free ends  18  of each tooth  12  have a preferred radius R 1  of about 0.013 inch, in this example, but R 1  can be extended to 0.16 inch. 
     In  FIG. 5 , a cross-section taken along  5 - 5  of  FIG. 4  of the teeth  12  is shown. As shown, the teeth  12  have a square cross-section for almost their entire lengths. The dimension D 5  for the sides of each tooth  12  is 0.039 inch, and the diameter D 6  of 0.052 inch, in the preferred embodiment of the invention. Also, D 5  can range 0.032 inch to 0.042 inch, and D 6  can range from 0.045 inch to 0.060 inch. With regard to the use of a square cross-sectional shape for the teeth  12 , the present inventors determined that the square shape provides the greatest rigidity and strength to the teeth  12 , for avoiding bending thereof during use. In this manner, through use of metal teeth  12 , it was further determined that longer teeth  12  can be utilized than obtainable with plastic. Long plastic teeth greater than 0.625 inch in length tend to bend during use, rendering them prone to break, and ineffective in comparison to much longer metal teeth. It was also determined that a diamond-shape for the cross section of the teeth  12  is less preferred from both a strength and rigidity standpoint. It was further determined through experimentation that the longitudinal edges or corner edges  22  of each tooth  12  should be slightly rounded, preferably with a radius R 2  of about 0.005 inch. Through use of the rounded edges  22 , it was determined that hairs would more easily be passed through the gap S 1  between the teeth, along with a greatly reduced chance of cutting hairs, while maintaining the gap S 1  at its preferred dimension of 0.004 inch to trap any lice or nits along almost the entire lengths of the teeth  12  during use. It should be noted that the nits or lice eggs have a length of about 0.028 inch to 0.04 inch, and a width of 0.012 inch to 0.020 inch. The hatched insect or head lice typically have a length of about 0.039 inch to 0.051 inch. The gap or spacing S 1  between opposing edges  22  of the teeth  12  can range between 0.0035 inch to 0.0045 inch. The preferred gap S 1  of 0.004 inch between the teeth  12  will permit opposing edges  22  thereof to capture the eggs and head lice by scrapping them off the hairs and entrapping them between the teeth  12 . It was further determined that stainless steel is the preferred material for the teeth  12 . The inventors further determine that through the use of metal teeth  12 , the teeth will remain substantially more rigid than plastic teeth, and have less tendency to flex or break. Through use of a square cross section in combination with the metal teeth  12 , the inventors determined that the teeth  12  have the strength to resist any movement during use, thereby avoiding catching hairs and pulling hairs out of the user. As previously mentioned, through use of long metal teeth  12 , more hairs can be wiped, when compared to combs using relatively shorter plastic teeth. 
       FIG. 6  shows a bottom plan view of the distal ends of the teeth  12 . As shown, the free or distal ends  23  are rounded with a radius R 1  of 0.013 inch, for the preferred embodiment. As previously mentioned, R 1  can be extended to 0.016 inch. D 5  and D 6  dimensions are given above. 
       FIG. 7  shows an alternative embodiment of the invention that includes a differently shaped handle  24 . As with the previous embodiment, the teeth  12  are in the same plane, and are configured as previously described. The length D 1  of each tooth  12  remains in the preferred embodiment at 1.897 inches, and the exposed length of each tooth  12  shown as D 2  is 1.425 inches. In this example, the total length of the alternative comb embodiment  26  shown as D 7  is 2.462 inches, with the width of alternative handle  24  D 8  being in the preferred embodiment 1.037 inches. The length D 9  of the alternative comb  26  is in the preferred embodiment 2.122 inches. As shown in  FIG. 8 , the thickness D 12  of the handle  24  is 0.25 inch in the preferred embodiment. 
     As shown in  FIG. 9A  for another embodiment of the invention, the teeth  12  are arranged in a convex configuration, that is form a curved configuration like the exterior of a circle. The radius R 3  in the preferred embodiment is 2.1457 inches.  FIG. 9B  is a cross section taken along  9 B- 9 B of  FIG. 9A , and would coincidentally appear the same for other embodiments of the invention 
     Through experimentation the inventors developed a process for manufacturing the teeth  12 . More specifically, stainless steel wire is pulled through cutters for producing a square shape to the wire. The square-shaped wire is then cut into the required lengths for the teeth  12 . The distal tips of the teeth  12  are then radiused to produce the rounded ends  18  of the teeth  12 . The proximal ends  16  are machined to form the notches  16 . The teeth  12  are then loaded into an insert that is placed into a mold for molding appropriate plastic material about the teeth  12 , to form the completed comb  2  or  24 . The mold is configured to hold the teeth  12  in proper alignment during the molding process. 
     Although various embodiments of the invention have been shown and described, they are not meant to be limiting. Those of skill in the art may recognize certain modifications to these embodiments, which modifications are meant to be covered by the spirit and scope of the appended claims. For example, the teeth  12  can be provided with a rough texturing in order to further enhance their scrapping action in removing lice and nits.