Abstract:
A method of making safety toothbrushes is disclosed. The toothbrush apparatus detailed herein employs a composite head made from a rigid inner polymer material and a softer thermoplastic material surrounding the inner material. The softer material provides safety for prison toothbrush applications as well as elderly and patient care where care givers may brush the teeth of the patient. The solution is importantly devoid of glue due to bonding that occurs during the mold curing process.

Description:
PRIORITY CLAIM 
       [0001]    This patent application is a continuation-in-part, and therefore contains subject matter claiming benefit of the priority date of pending U.S. patent application Ser. No. 11/653,153 filed on Jan. 12, 2007 and entitled, PACKAGED TOOTHBRUSH AND TOOTHBRUSH CONTAINER AND METHODS OF MAKING SAME; which is further a continuation-in-part of, and claims benefit of the priority date of U.S. patent application Ser. No. 11/563,671, now U.S. Pat. No. 8,448,285 filed on Nov. 27, 2006 and entitled TOOTHBRUSH AND METHODS OF MAKING AND USING SAME, accordingly, the entire contents of these patent applications are hereby expressly incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention pertains generally to toothbrush devices. More specifically, the invention relates to novel methods for making toothbrushes with safety features particularly useful for prisons, hospitals and patient/elderly care. 
         [0004]    2. Description of the Prior Art 
         [0005]    Prison and other detention systems restrict certain hygiene items used by inmates to prevent the use of an otherwise safe device as a weapon. For example, conventional toothbrushes are not permitted to be used by many prison systems because they may be fashioned into a pointed shaft or rod or otherwise known as a shank, which could be used to endanger other inmates or themselves, as well as security personnel. Psychiatric and other mental health systems likewise require toothbrushes that cannot cause self-injury or harm to care givers or security personnel. 
         [0006]    A previous attempt to provide a safe alternative toothbrush for use by inmates was a toothbrush simply having a brush head and a very short handle. Further, said handle is so short that it must be grasped by only the thumb and forefinger of the user. However, such a toothbrush is awkward to use. The fingers of the user may be required to enter the mouth to reach all of the teeth. Such a difficult to use toothbrush may only provide marginal teeth cleaning and be uncomfortable to use. Further ineffectual cleaning procedures may cause, or at the least contribute to, poor dental hygiene, thereby leading to costly dental procedures in some instances. 
         [0007]    Toothbrushes having a flexible handle, therefore deterring inmates ability to fashion into a shank have further been heretofore known. One such example was proposed by inventor Phillips, entitled “Flexible Toothbrush,” U. S. Pat. No. 6,295,686. This particular design has a handle portion, reference character sixteen, that is flexible. The handle portion is further coupled to a neck portion, reference character fourteen. The material used in the toothbrush design additionally comprises 50% thermoplastic rubber and 50% polypropylene. As compared to Philips however, the present invention incorporates added design benefits that improve wear characteristics and facilitate use. 
         [0008]    The present invention additionally pertains to injection molding methods of making toothbrushes. Additionally further, the invention relates to a toothbrush design that is molded with more than one material in the molding process. A related example is provided by Leversby et al., entitled “Toothbrush Structure,” U.S. Pat. No. 6,276,020. Leversby and his co-inventors describe a toothbrush design with two materials included in the molding process to generally improve strength of the toothbrush and provide a non-slip surface for grasping. There remains a need, however, for a toothbrush head being resilient for strength but however having an outer softer material. There further remains a need for a method for making such toothbrushes. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The present invention specifically addresses and alleviates the above mentioned deficiencies associated with the prior art. More particularly, the present invention in a first aspect, is directed to a method for making a flexible handle toothbrush comprising the steps of: molding an inner toothbrush head with a first material, the first material being rigid; and molding an outer toothbrush head with a second material around the inner toothbrush head, the second material being pliable, wherein the outer and inner toothbrush heads together form a composite toothbrush head, wherein a method step of molding the inner toothbrush head precedes a step of molding the outer toothbrush head. 
         [0010]    As in all the methods discussed herein, the composite toothbrush head is devoid of glue or other adhesives. The preferred method herein also employs two single cavity molds. Still further, the invention in this aspect is additionally characterized wherein the method steps of molding an inner toothbrush head and molding an outer toothbrush head include allowing for a pair of pin connectors (two or more) at the interface of the inner toothbrush head and the outer toothbrush head, wherein further the pins are offset diagonally with respect to a longitudinal axis of the flexible handle toothbrush. 
         [0011]    The present invention in another aspect is a method for making a flexible handle toothbrush comprising the steps of: making a first mold for an inner toothbrush head; selecting a first rigid material for use in the first mold; molding an inner toothbrush head with the first mold; and making a second mold for an outer toothbrush head, the inner and outer toothbrush head forming a composite toothbrush head. 
         [0012]    The method for making a flexible handle toothbrush in this aspect is additionally characterized as including the steps of: selecting a second pliable material for the second mold, the second material having a softness preventing damage to a patient&#39;s teeth or gums due to brushing, while further preventing a user from fashioning the toothbrush into a weapon; molding the outer toothbrush head around the inner toothbrush head; and curing the second material around the first material thereby bonding without the use of glue or other adhesives. 
         [0013]    These, as well as other advantages of the present invention will be more apparent from the following description and drawings. It is understood that changes in the specific structure shown and described may be made within the scope of the claims, without departing from the spirit of the invention, such as a variety of positions for pin placement as described herein. 
         [0014]    While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The invention can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0016]      FIG. 1  is a perspective view of toothbrush embodiment made from a preferred method herein; 
           [0017]      FIG. 2  is a profile view with a partial sectional view thereof taken along line  2 - 2  in  FIG. 1  and in  FIG. 3 ; 
           [0018]      FIG. 3  is a bottom view of the toothbrush embodiment; 
           [0019]      FIG. 4  is an enlarged view of an area circumscribed by line  4  in  FIG. 2 ; and 
           [0020]      FIG. 5  is a functional block diagram of a preferred method. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Various inventive features are described below that can each be used independently of one another or in combination with other features. 
         [0022]    Initially, with reference to  FIG. 1 , a flexible handle toothbrush  10  is shown that particularly meet a need in the prison, hospital or institutional application. As shown, the toothbrush  10  has an inner toothbrush head  11  made with a first material. The first material is ideally made from a rigid polymer material, therefore providing structural integrity to the toothbrush  10  head  20  allowing for attachment of bristles  57  in the production process. Further, an outer toothbrush head  12  is manufactured from extrudable elastomer material, e.g. thermoplastic material, thereby making this material  12  soft and pliable, hence, safer for prison environments or patient care institutions. Additionally as shown, a handle portion is comprised of the same flexible material as the outer toothbrush head. 
         [0023]    With regard to  FIG. 2 , a profile of the toothbrush  10  is provide with a partial sectional view thereof taken along line  2 - 2  in  FIG. 1  and in  FIG. 3 . This together with  FIG. 4  illustrates the composite toothbrush head  20  with inner  11  and outer  12  portions having a pair (or more, or at least one) of pins  21 ,  22  at the interface thereof. Importantly, two separate single cavity molds are employed and the method step  55  of molding the inner toothbrush head  11  precedes a step of molding the outer toothbrush head  56 . In molding the outer toothbrush head  12 , the inner toothbrush head is inserted inside the outer toothbrush head (plus handle) mold. The outer toothbrush plus handle mold will have a cavity to receive the inner toothbrush head having approximately bristle holes drilled thereto. Importantly, the composite toothbrush head  20  is devoid of glue, as additionally detailed herein. Further, the manufacturing the composite head  20  will employ two single cavity molds. 
         [0024]    With regard to  FIG. 3 , a bottom view of the toothbrush is shown particularly illustrating placement of the interfacing pins  21 ,  22  of the present invention. As stated pin connectors  21 ,  22  are employed to strengthen the mating between inner and outer toothbrush head. More specifically, the pins  21 ,  22  are offset diagonally with respect to a longitudinal axis of the flexible handle toothbrush  10 , as shown. Also, with regard to the pins, they are useful to maintain the inner head  11  stationary while positioned in the cavity of the outer head (plus handle) mold. Also as contemplated by the present invention, the two or more pins  21 ,  22  can be positioned anywhere along the interface between inner  11  and outer  12  heads, as long as the inner head stays stationary in the cavity portion of the outer head  12  mold. 
         [0025]    With regard to  FIG. 5 , a functional block diagram illustrating a method  50  of making flexible handle toothbrushes is illustrated. Initially a first mold is made  51  for the inner toothbrush head  11 . Next, a first rigid material is selected  53  for use in the first mold and a second mold for the outer toothbrush head is made  52 . A second pliable material  54  is then selected for the outer toothbrush head  12 , providing a softness preventing damage to a patient&#39;s teeth or gums due to brushing and to prevent fashioning into a weapon. Optionally, color is added to a hopper containing the second pliable material. 
         [0026]    As stated, the method step of molding the inner toothbrush head  55  precedes the step of molding the outer toothbrush head  56 . More specifically, the completed toothbrush inner head  11  may be placed in the cavity of the second mold  56 . Also importantly the second material is cured around the first material to provide a bond devoid of glue due to its thermoplastic properties. The final step in the method herein is to insert  57  bristles  14  to the toothbrush head and determine batch size  58 ,  59 . 
         [0027]    Additionally, a preferred method includes the steps of: drilling a multiplicity of bristle holes on a surface of the inner toothbrush head  11 , as best seen and  FIG. 4 . The drilling is subsequent to the making  55  the inner toothbrush head. Further included is a method step of filling the multiplicity of bristle holes  13  with steel pins so that during the method step of molding an outer toothbrush head  56 , no outer toothbrush head material  54  flows into the bristles holes. 
         [0028]    Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiments have been set forth only for the purposes of example and that it should not be taken as limiting the invention as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the invention includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations. 
         [0029]    While the particular Method for Making Safety Toothbrushes as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims. 
         [0030]    Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.