Patent Publication Number: US-2006011212-A1

Title: Manual advance dental floss holder

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
      This patent application claims the benefit of U.S. Provisional Patent Application No. 60/600,395, filed Aug. 10, 2004, the disclosure of which is hereby incorporated in its entirety by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      This invention relates generally to devices for holding dental floss, and, more particularly, to an improved device for holding a protected supply of dental floss, presenting a tensioned portion of the floss for use in flossing, and advancing the floss through the device to provide a fresh portion of floss as needed.  
      Traditionally, dental floss is used by grasping the ends of a length of floss and reciprocating the floss back and forth in the spaces between the teeth. Dental floss is usually supplied for this purpose in small spools from which lengths of floss are cut off as needed, wrapped around the fingers of the user&#39;s hands, and manually held under tension as the floss is reciprocated back and forth in the spaces between the teeth.  
      In order to ensure a good grip on such manually-grasped floss, the ends of the floss must be securely wrapped around the user&#39;s fingers. This is often uncomfortable, particularly as the flossing operation proceeds and the floss cuts into the user&#39;s fingers. Also, in order to ensure that the floss does not come loose from the user&#39;s fingers, it is necessary to include a leader of at least several inches at either end of the length of floss being used, so that this leader can be turned around the user&#39;s fingers at least several times. This leader is not used in the actual flossing in the spaces between the teeth and is therefore wasted. Finally, the entire length of floss is vulnerable to contamination by bacteria on the user&#39;s hand and in the surrounding environment to which the floss is exposed.  
      Floss holders which hold a supply of floss, eliminate the wasted leader and the discomfort of traditional flossing techniques, and can be held in one hand while passing an exposed portion of the floss between the user&#39;s teeth are known. There are myriad such devices with a variety of different mechanisms for supporting the exposed portion of the floss which is to be reciprocated back and forth in the spaces between the teeth and for advancing the floss through the device, as it is spent. All such devices are complex in their design and operation.  
      It is therefore an object of the present invention to provide a floss holder which may be conveniently grasped in one hand and manually operated, and which is simple and straightforward in its construction and operation. The present new and improved floss holder is simple and inexpensive to construct, particularly comfortable to grasp, and convenient to use single-handedly. It holds the portion of floss presented for flossing under uniform and proper tension and it protects the supply of unused floss from contamination. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and advantages, may be best understood by reference to the following description, taken in conjunction with the following drawings, in which like reference numbers identify like elements in the several figures and in which:  
       FIG. 1  is a perspective view of a floss holder in accordance with the present invention, highlighting the prongs holding an exposed portion of floss;  
       FIG. 2  is a front elevation view of the floss holder of  FIG. 1 ;  
       FIG. 3  is a side elevation view of the floss holder of  FIG. 1 ;  
       FIG. 4  is an elevation view of the floss holder of  FIG. 1 , with the cover of the holder separated from the bottom, exposing a portion of the internal mechanism of the device;  
       FIGS. 5A and 5B  are, respectively, cut-away front elevation views of the floss holder of  FIG. 1  showing the floss control mechanism of the device in the absence of floss ( FIG. 5A ) and with floss supplied to the floss control mechanism ( FIG. 5B );  
       FIG. 6A  is a top plan view of the inside of the cover of a floss holder in accordance with  FIG. 1 ;  
       FIG. 7  is a top plan view of the inside of the base of a floss holder in accordance with  FIG. 1 ;  
       FIG. 8  is a perspective view of the knurled dial of the floss holder from the ratchet wheel side, including the spring metal ratchet finger plate showing fingers of the plate resting against ratchet teeth;  
       FIG. 9  is an enlarged partial perspective view of several ratchet teeth of the ratchet wheel of  FIG. 8  showing the contour of the ratchet teeth and a spring metal ratchet finger resting upon one of the teeth;  
       FIG. 10  is a perspective view of a spool of floss from the floss holder of  FIG. 1 ;  
       FIG. 11  is a top plan view of the spring plate of the floss holder of  FIG. 1  showing the fingers of the plate that engage sprocket teeth on the floss spool;  
       FIG. 12  is an enlarged partial perspective view of the head of the floss holder of  FIG. 1  showing the prongs of the device, as well as a groove in the outer edge of one of the prongs which receives floss from an opening in the floss holder through which the floss passes;  
       FIG. 13  is a cut-away side elevation view of the floss holder of  FIG. 1  taken along lines  13 - 13  of  FIG. 2  showing the knurled dial and the floss spool mounted in the device; and  
       FIG. 14  is a perspective view of a floss holder in accordance with  FIG. 1  resting in an upright position in a receptacle designed to be disposed on a horizontal surface.  
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
      Turning to  FIGS. 1-3 , floss holder  10  in accordance with the present invention is shown including a body  12  having a tapered end  14 , a bulbous gripping portion  16 , and a tapered neck  18 . A fork  20 , which is located at the distal end of the body, includes generally distally directed spaced apart tines  22  and  24 . The front of the body of the floss holder is designated by the number  26  and the back of the body of the floss holder is designated by the number  28 . Generally longitudinally disposed elongated rectangular openings  29  and  31  are formed in the front and back of gripping portion  16  of the body through which a knurled dial  30  protrudes. This knurled dial is associated with the take-up spool of the device as will be explained below.  
      Neck  18  of the floss holder includes outgoing floss channel  42  located just below the bottom outer edge of tine  24  and an ingoing floss channel  44  located just below the bottom outer edge of tine  22 . Ingoing floss channel  44  may be best seen in the enlarged view of the fork of the floss holder of  FIG. 12 . Additionally, slots  25  and  27  are formed along the outer edges of tines  22  and  24  to maintain the floss in place along the outer edges of the tines as fresh floss is moved from outgoing floss channel  42  across tines  22  and  24  and spent floss moves back into the device through ingoing floss channel  44 .  
      The body of floss holder  10  is made of a rigid material such as a hard plastic like ABS or polypropylene that can be easily molded to the illustrated shape. Among these polypropylene is currently preferred. The floss holder is preferably made in two parts ( FIG. 4 ), a cover  25  and a bottom  27 , joined by a locking tab at  18  and a screw (not shown). It is preferred that the outside of the cover and the bottom include respective elastomeric gripping sections  32  and  34  formed into the surface of the gripping portion of the holder encircling openings  29  and  31 . These sections may be made, for example, from thermoplastic elastomers. If a thermoplastic elastomer is used, styrene ethylbutylene styrene (SEBS) is currently preferred. The elastomeric sections may extend into the neck  18  of the floss holder as shown. An arrow  40  may be formed in elastomeric section  32  as shown to indicate the direction in which knurled dial is intended to be moved in order to advance floss in the device. A like arrow (not shown) may also be formed in elastomeric section  34 . Additionally, a gripping texture, provided for example by a series of laterally disposed upstanding ribs  36  and  38 , may be formed in the distal ends  39  and  41  of the elastomeric sections as shown.  
      Floss holder  10  is intended to be grasped by wrapping the user&#39;s fingers around gripping portion  16  so that the user&#39;s thumb may easily contact knurled dial  30  at either or both of the front and the back of the device when it is desired to advance fresh floss across tines  22  and  24  or to take up slack in the floss, as will be described below. Once fresh floss is in position as required, the user may if desired shift his or her forefinger and thumb to grasp ribs  36  and  38  to facilitate the manipulation of the floss holder as the floss is moved between the user&#39;s teeth in the appropriate flossing motion.  
      The floss control mechanism  50  of floss holder  10  disposed within the interior  51  of the device as illustrated in  FIGS. 4, 5A ,  5 B and  13 . The floss control mechanism includes a supply reel  52  (see also  FIG. 10 ) for holding fresh, unused floss and a take-up reel  54  for holding used or spent floss mounted for rotary movement about their respective lateral axes  56  and  58 . The supply and take-up reels include respective cylindrical bearing surfaces or pins  60 / 62  and  64 / 66 , that project laterally from opposite sides of the reels. These pins are located, as shown, in corresponding apertures  68 / 70  and  72 / 74 .  
      Take-up reel  54  includes an annular take-up spool section  90  having a side plate  57  and a knurled dial  30 . The knurled dial is of a diameter large enough to ensure that it protrudes from openings  29  and  31  in the gripping portion of the device, as described above in connection with  FIGS. 1-3 . Also, the protuberances or knurls  31  ( FIG. 8 ) facilitate rotation of the knurled dial by the user&#39;s thumb and forefinger when desired. Finally, ratchet wheel  80  is affixed to face  82  of knurled dial  30  and thereby comprises a component of the take-up reel. Thus, bearing surfaces  60  and  62 , annular take-up spool section  90 , side plate  57 , knurled dial  30  and ratchet wheel  80  are centered on axis  58  and make up take-up reel  54 .  
      Ratchet wheel  80  has a series of ratchet teeth  84  ( FIGS. 8 and 9 ) each with a ramp portion  86  and a generally radially disposed descending portion  88 . Ratcheting action is achieved through the cooperation of ratchet teeth  84  and a pawl  200 . A resilient pawl  200  is formed in a first spring plate  202  mounted in the floss holder adjacent the ratchet teeth, as illustrated, for example, in  FIG. 4 . Spring plate  202  thus includes a generally flat base  204  having a circular aperture  206  with an upstanding lip  208 . The aperture and lip receive pin  66  of the take-up reel snugly, but with enough space to permit unimpeded rotation of the take-up reel. If desired, an appropriate lubricant may be applied at the interface of the pin and the inner surface of the lip. Spring plate  202  further includes upstanding walls  210  and  212 , which rest respectively against the inside surface of cover  25  and bottom  27  of the floss holder which together lock the spring plate in place in the fully assembled floss holder. A spring finger  214  is formed along the edge  216  of the spring plate extending beyond the center of aperture  206 . Spring finger  214  includes a distal portion or pawl  200  which is bent at an angle to the plane of the spring plate generally corresponding to the angle of ramp portion  86 , as seen in  FIG. 8 . Spring finger  214  is formed with sufficient material at its base, taking the thickness and spring characteristics of the metal from which the spring plate is made, to ensure that the finger has sufficient flexibility and appropriate springback characteristics to ensure continuous reliable performance of pawl  200  over time. Currently it is preferred that 0.010 to 0.015 stainless spring steel be used. Thus, pawl  200  rests against ramp portion  86  of ratchet wheel  80  but flexes to permit the ratchet wheel and hence the take-up reel to turn in direction A (counterclockwise) as pawl  200  rides up along the ramp portions  86  of succeeding ratchet teeth  84  and presses back into descending portions  88  of the ratchet teeth. Pawl  200  thus permits rotation of the take-up wheel in direction A (clockwise in  FIG. 8 ) while preventing the take-up reel from turning in the opposite (counterclockwise) direction since the distal end  218  of the pawl abuts descending portion  88  of the next ratchet tooth when movement in the counterclockwise direction is attempted and will not flex or move out of the way.  
      Although floss may be attached to the take-up reel in any desired fashion, one way in which this can be done is by forming a hole in knurled dial  30  as shown, passing the end of the floss through the hole, forming a knot in the end of the floss which prevents the floss from being pulled back through the hole and then advancing the take-up reel in direction A to wind the floss on spool  90 . Another way to attach the floss would be to form a narrow space between parts of the take-up reel and to force the end of the floss into that space thereby retaining it by friction.  
      Turning now to  FIGS. 5A, 5B  and  10 , supply reel  52  is shown comprising a pair of toothed wheels  100  and  102  disposed on opposite sides of spool  104  of the supply reel. (A single toothed wheel could, of course, be used.) Spool  104  is pre-wound with an appropriate supply of floss  127  before the device is assembled. In one embodiment, up to 12 yards of floss may be pre-wound onto spool  104 .  
      A second spring plate or metering member  106  is provided in the proximal end  107  of the interior of bottom  27  of the floss holder. This metering member is made of an appropriate resilient material and includes a base portion  108  having an aperture  110 , which is located on a pin  112  molded into the bottom surface  111  of the handle. The metering member is of a wishbone configuration and includes a pair of resilient arms  114  and  116 , which engage toothed wheels  100  and  102  symmetrically across the supply reel to resist movement of the supply reel as floss is drawn from it when the take-up wheel is rotated. Indeed, when the reel is at rest the distal ends  115  and  117  of the arms will sit in the grooves  103  between adjacent toothed wheels to produce a “lock” effect in the form of increased resistance to movement from the rest position.  
      Metering member  106  should be made of a material having a resilience that will resist turning under the forces to which it is subjected when the exposed floss portion is being used in flossing but will allow the tooth wheels and hence reel  52  to rotate the minimum necessary distance and without overshooting dictated by the pulling forces to which the floss is subjected when knurled dial  30  is rotated in a clockwise direction to advance or draw clean floss onto tines  22  and  24 . The resistance provided by the cooperating resilient arms of the metering member and the toothed wheels also will permit limited floss movement when excessive force is applied during flossing to minimize stretching of the floss and to prevent damage to the floss or the floss holder. Currently, the metering member is made of stainless spring steel between 0.012 to 0.020 inches in thickness.  
      Sufficient friction is provided by the engagement of the metering member with the toothed wheels to maintain tension in the floss running from the supply reel, in slots  25  and  27 , across the fork, and to the take-up reel, to ensure that the exposed floss portion will remain taut. This friction thus also maintains the exposed floss portion in the desired location during use and ensures that it is be available to be used effectively in flossing the teeth without causing undesirable sag in the exposed floss portion. However, in the event that the floss stretches during use or sufficient force is applied to overcome the friction provided by the engagement of the metering member with the toothed wheels, the slack can be taken up by simply rotating the take-up spool, preferably as the floss holder is being used. Additionally, as the toothed wheels move against the metering member an audible clicking sound is produced that signals the advance of clean floss within the floss holder.  
      The interior  51  of the floss holder includes generally isolated compartments, namely a fresh floss supply compartment  120 , a spent floss holding compartment  122 , and a spent floss return compartment  124 . These compartments are defined by upstanding walls  126  and  128  and lip  130  in floss holder bottom  27  and corresponding upstanding walls  132  and  134  in floss holder cover  25 . Walls  126 / 128  and  132 / 134  abut and lip  130  rests against the inside of the cover when the cover and bottom are assembled. Walled compartments  120 ,  122  and  124  respectively isolate fresh outgoing floss (compartment  120 ) from incoming spent floss (compartments  122  and  124 ), as will be explained in more detail below. This isolation of the fresh and spent floss minimizes cross-contamination between the fresh outgoing floss and the incoming spent floss.  
      When floss holder  10  is ready to be assembled, floss  127  will be threaded as shown in  FIG. 5B  from supply reel  52  up through compartment  120  and outgoing floss channel  42 , along slot  25 , across tines  22  and  24  back down through slot  27  through ingoing floss channel  44 , through compartment  124  across floss passage  134  in wall  128 , into compartment  122  and onto the take-up spool. Here the floss is attached, for example, by passing the end of the floss through a hole in the wall of the take-up spool and forming an appropriately-sized knot (not shown) to resist removal of the floss or by forcing the end of the floss into a tight-fitting slot where it will be held by friction. The cover and bottom of the floss holder are then fit together ( FIG. 4 ) and the two parts are fixed together as discussed earlier.  
      Once the floss holder is assembled and ready for use, the user grasps gripping portion  16  and orients fork  20  with the exposed floss portion  136  in the interstices between the user&#39;s teeth. The floss holder is then manipulated to move the exposed floss portion as appropriate, to thereby clean the spaces between the teeth and exercise the gums as recommended for proper dental hygiene.  
      When the exposed floss portion is spent, the user presses their thumb and/or forefinger against the protruding portion of knurled dial  30  and applies sufficient rotary force to advance the take-up reel in a clockwise direction as shown by arrow A in  FIG. 5  against the resistance presented at the supply reel. This direction of movement is permitted by pawl  200 , which rides along the ramps of the teeth of ratchet wheel  80  as the take-up wheel is rotated. Thus, as the take-up wheel is rotated, floss is drawn from the supply reel causing the supply reel to rotate, as arms  114  and  116  of metering member  106  ride along toothed wheels  100  and  102 . The tension applied by the user in rotating the take-up reel combined with the locking action of pawl  200  and ratchet teeth  84  and the resistance provided by toothed wheels  100  and  102  and metering member  106  prevents unintended rotation of the reels and maintains the desired tension in the exposed floss portion as it is used in flossing.  
      Finally, a receptacle  250  may be provided for the floss holder as illustrated in  FIG. 14 . Receptacle  250  includes an upwardly directed hollow portion  252  configured to receive the tapered end  14  of the floss holder. Hollow portion  252  of the receptacle is affixed to a generally planar base  254 . Receptacle  250  thus makes it possible to conveniently store the floss holder between uses by placing receptacle  250  on a generally horizontal surface such as a shelf and placing the tapered end of the floss holder in receiving portion  252 . When needed, the floss holder can be simply removed from the receptacle, used, and then returned for storage until the next use. Storage in this manner facilitates drying of exposed floss in the floss holder.  
      It should be understood that the form of the invention as shown and described above is to be taken as a preferred example, and that variations in the shape, size, arrangement and operation of the floss holder may be made without departing from the spirit or scope of the invention.  
      Although preferred embodiments of the present invention has been described foregoing Detailed Description and illustrated in the accompanying drawings, it should be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention. Accordingly, the present invention is intended to encompass such rearrangements, modifications, and substitutions as fall within the scope of the appended claims.