Abstract:
A dental floss clamp comprising a screw connection having a threaded nut and a threaded bolt which is moveable within a longitudinal axis of the threaded nut and can be screwed therein wherein the threaded nut comprises a jacket and has an interior thread and an interior groove; the threaded bolt has an exterior thread and an exterior groove; each turn of the interior thread has a first flank , and a second flank, each having a pitch; and wherein the pitch of the second flank with respect to the longitudinal axis of the threaded nut is greater than the pitch of the first flank.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a handling aid for dental floss and particularly to a clamp for dental floss. 
       BACKGROUND OF THE INVENTION 
       [0002]    Dental floss is a well-known article used to promote oral hygiene by aiding in the removal of particles lodged in the interproxminal areas of the teeth. In interdental spaces, the tooth surfaces are best freed from plaque by means of dental floss. The surface of conventional dental floss is generally smooth and is sometimes waxed. This makes it difficult for an individual to hold the floss during use because it can not be tightly grasped and slips between the user&#39;s fingers. The handling of conventional dental floss is thus difficult. 
         [0003]    Often floss is purchased and packaged in a container/dispenser having an internal chamber for securely holding a large continuous length of floss wrapped around a spool or bobbin. A length of floss can be drawn and separated from the spooled portion remaining within the container. The floss emerges through a slit on the top of the container and can be separated from the bobbin by a cutting device. For a typical example see U.S. Des. Pat. No. 339,426. To floss the teeth, a person usually wraps the ends of the floss round the forefinger of each hand to be able to impose tension on a short length of the floss to thereby squeeze it between teeth and manipulate it to remove plaque. This can become painful if the floss is wrapped too tightly, or when the floss becomes taut during use. The resulting constriction of the fingers is unpleasant, and the fingers may remain constricted during the cleaning of a complete set of teeth. Furthermore, lack of control of the floss can lead to cutting of the gums. The chances of this happening increase when the floss is moistened by saliva as the friction between a user&#39;s fingers and the floss decreases if the surfaces are moistened. The dental floss can then slip. 
         [0004]    Accordingly, an object of the invention is the provision of a device that eliminates the need to wrap the floss round the fingers and which allows the user to effectively control the tension of the floss. It is known in the art that it is desirable for floss to form a closed loop so that tension may be applied on or at a selected portion of the loop that is inserted between the teeth. When utilising a dental floss loop, the fingers need only be constricted during the cleaning of one interdental space. When switching to the next interdental space, the constriction is interrupted as the user moves the floss. Additionally, as this brings into engagement, with the interdental spaces, a different region of the dental floss loop, excessive local use of the floss is avoided. In U.S. Pat. No. 4,550,741, flexible strands are closed by a joining means, and in U.S. Pat. No. 5,947,132 a plurality of flossing loops are connected to form a cascade of loops, provided in a dispenser. U.S. Pat. No. 5,799,673 discloses dental floss with finger loops. A plurality of lengths of floss is provided, each having a finger loop at each end. The lengths of floss are removably connected to each other to form a single continuous piece and are stored within a dispenser. However, there remains a need to find a more efficient way of forming a dental floss loop. 
         [0005]    It is the goal of the invention to facilitate the handling of the dental floss by providing a dental floss clamp. The clamp allows the formation of a dental floss loop from a continuous strand of floss and provides several points of contact with the floss which increase friction forces on the floss and thus reduce the risk of the floss slipping when held in the clamp. Consequently, tension can be maintained in the floss throughout use and the need to wind the floss around the user&#39;s fingers is removed. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to a dental floss clamp comprising a screw connection having a threaded nut and a threaded bolt which is moveable within a longitudinal axis of the threaded nut and can be screwed therein wherein the threaded nut comprises a jacket and has an interior thread and an interior groove; the threaded bolt has an exterior thread and an exterior groove; each turn of the interior thread has a first flank, and a second flank, each having a pitch; and wherein the pitch of the second flank with respect to the longitudinal axis of the threaded nut is greater than the pitch of the first flank. 
         [0007]    The invention further relates to use of the dental floss clamp for securing a piece of dental floss and for forming a dental floss loop. 
         [0008]    Additionally, the invention relates to a kit comprising the dental floss clamp and a piece of dental floss. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  shows a longitudinal section in plane B-B of the floss clamp shown in  FIG. 3 . 
           [0010]      FIG. 2  shows a longitudinal section in plane A-A of the floss clamp shown in  FIG. 1 . 
           [0011]      FIG. 3  shows a view in direction C of the floss clamp shown in  FIG. 1 . 
           [0012]      FIG. 4  shows a longitudinal section in plane B-B of the floss clamp shown in  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    Referring first to  FIGS. 1 to 3 , a dental floss clamp  100  comprises a threaded nut  110  and a threaded bolt  210 . Preferably the threaded nut  110  and the threaded bolt  210  are made of a plastic material in a two-component injection molding process. The plastic material for the threaded nut  110  may be polyamide. Preferably the plastic material of the threaded bolt  210  is a different material, preferably polyethylene, to that of the threaded bolt in order to prevent the two components sticking together during the injection molding process. 
         [0014]    The threaded nut  110  can be injected and can then serve as a mould for the threaded bolt  210 . After the injection of the threaded bolt  210  into the threaded nut  110 , the threaded bolt  210  shrinks during cooling and a space is created. The threaded bolt  210  thus becomes movable in the threaded nut  110 . To aid this process, preferably the melting point of the plastic material which forms the threaded bolt  210  is lower than the glass transition temperature of the plastic material which forms the threaded nut  110 . 
         [0015]    The threaded nut  110  comprises a jacket  111 , an interior thread  112  and an interior groove  113 . Preferably the jacket  111  is cylindrical. Preferably the threaded nut  110  further comprises two bevels  114  and a stop  115 . The bevels  114  facilitate introduction of the floss into the interior groove  113 . Preferably the interior thread  112  is right-handed. Each turn of the interior thread  112  has a first flank  116  with a pitch x, and a second flank  118  with a pitch y. The pitch y of the second flank  118  with respect to the longitudinal axis of the threaded nut  110  is greater than the pitch x of the first flank  116 . The pitches x and y are chosen to achieve the exterior thread of the threaded bolt becoming wedged in the interior thread of the threaded nut, thereby allowing a length of dental floss, placed in the groove  113 , to be secured between the threaded nut and the threaded bolt, with a rotation of  10  to  120  degrees of the threaded bolt within the threaded nut. 
         [0016]    The threaded bolt  210  has an exterior thread  212 , which matches the interior thread  112 . The exterior thread  212  has the same handed-ness as the interior thread  112 . Preferably the exterior thread  212  is right-handed. A groove  213  is located in the exterior thread  212 . The threaded bolt  210  preferably carries a toggle  215 , which rests against the stop  115 . When the interior and exterior threads  112 ,  212  are right-handed, the toggle and stop prevent the user turning the threaded bolt  210  in anti-clockwise direction. 
         [0017]    The threaded bolt  210  can preferably be turned against the threaded nut  110  in a clockwise direction  320 , until the space between the turns of the interior and exterior threads  112 ,  212  is depleted by the different pitches of the first and second flanks  116 ,  118 . The different pitches of the first and second flanks result in the exterior thread of the threaded bolt becoming wedged in the interior thread of the threaded nut, thereby allowing a length of dental floss to be secured between the threaded nut and the threaded bolt. This is preferably achieved within a rotation of 10 to 120 degrees of the threaded bolt within the threaded nut, more preferably within 10 to 60 degrees. 
         [0018]    The width of the interior and exterior grooves  113 ,  213 , the pitches of the flanks  116 ,  118  and the space between the threads  112 ,  212  are chosen in such a manner that the exterior groove  213  disappears completely in the interior groove  113  in the event of a rotation in a clockwise direction  320 . 
         [0019]    On the side of the grooves  113 ,  213  located in the direction  320 , at least one turn of the interior thread  112  preferably comprises a curve  120  which functions to provide a smooth bend of the floss without cutting it. On the side of the grooves  113 ,  213  located in the direction  310 , at least one turn of the exterior thread  212  preferably comprises a curve  220 . 
         [0020]    Referring to  FIG. 4 , the user can place two free ends of a length of dental floss  400  into the grooves  113 ,  213  in such a manner that a dental floss loop is created. By turning the threaded bolt  210  into the threaded nut  110  in the direction  320 , the free ends of the dental floss piece  400  are clamped between the turns of the threads  112 ,  212 . The free ends of the dental floss piece  400  thereby wind around the curves  120 ,  220 . The curves  120 ,  220  provide additional points of contact for the floss and the clamp increasing the friction forces present on the clamp, thus enabling the floss to be gripped in the clamp more securely. If the dental floss loop is pulled by the user, friction acts where the dental floss piece  400  is in contact with the clamp and improves the handling of the floss by increasing the tension and reducing the risk of the floss slipping. 
         [0021]    In one embodiment, the user can tighten the dental floss loop between two fingers and can thus remove the plaque in the interdental space. The handling is considerably simpler than without the dental floss clamp  100  because the user need not wrap the floss around their fingers to provide friction during use of the floss. Thus the problems of wrapping floss around the fingers, discussed in the background of the invention, are overcome. After the cleaning of the teeth, the user can open the dental floss clamp  100  by turning the threaded bolt  210  in the direction  310  until the toggle  215  touches the stop  115 . He can then remove the length of dental floss  400 . 
         [0022]    In an alternative embodiment the user need not form a dental floss loop. Instead, the user can place two dental floss clamps  100  at opposed ends of a length of dental floss. The dental floss clamps  100  can be positioned adjacent to the ends of the piece of floss. This will facilitate the handling of the floss by maintaining tension, and it will remove the need to wind the dental floss around the fingers. 
         [0023]    The dental floss may be packaged in a container having an internal chamber for securely holding a large continuous length of floss wrapped around a spool or bobbin. The threaded nut  110  and the threaded bolt  210  may be provided in the lid of the container from where either or both of the threaded nut  110  and threaded bolt  210  can be removed. Alternatively the dental floss clamp may be provided separately from the container. 
         [0024]    The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm ” 
         [0025]    Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
         [0026]    While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. 
       Description of Reference Numerals 
       [0027]      100  Dental Floss Clamp 
         [0028]      110  Threaded Nut 
         [0029]      111  Jacket 
         [0030]      112  Interior Thread 
         [0031]      113  Interior Groove 
         [0032]      114  Bevels 
         [0033]      115  Stop 
         [0034]      116  First Flank 
         [0035]    x Pitch of First Flank 
         [0036]      118  Second Flank 
         [0037]    y Pitch of Second Flank 
         [0038]      120  Curve of Interior Thread 
         [0039]      210  Threaded Bolt 
         [0040]      212  Exterior Thread 
         [0041]      213  Exterior Groove 
         [0042]      215  Toggle 
         [0043]      220  Curve of Exterior Thread 
         [0044]      310  Anti-clockwise Direction 
         [0045]      320  Clockwise Direction 
         [0046]      400  Length of Dental Floss