Abstract:
The present invention is an orthodontic ligature pliers, to facilitate engaging an orthodontic elastic ligature to an orthodontic bracket, which is attached to a patient&#39;s tooth allows the removal of two o-rings from an elastic ligature stick at a time, allowing the user to attach the two o-rings, each in a separate step to two brackets, without having to return to the o-ring stick allows the user to place two o-rings at the mouth on separate brackets, without having to return to the o-ring stick to replenish the o-ring after each previous o-ring is applied.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/377,875, filed on May 3, 2002, entitled DOUBLE HEADED ORTHODONTIC LIGATURE PLIERS. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention is a double headed orthodontic ligature pliers and method for transferring more than one orthodontic elastic ligature at a time, to facilitate engaging an orthodontic elastic ligature (also referred to herein as an o-ring) to an orthodontic bracket, the latter attached to a patient&#39;s tooth. Instead of taking one o-ring at a time and attaching it to one bracket at a time, this invention allows the removal of two o-rings from an elastic ligature stick (also referred to herein as an o-ring stick) at a time, allowing the user to attach the two o-rings, each in a separate step to a bracket, without having to return to the o-ring stick. The invention doesn&#39;t tie two o-rings to brackets at the same time, but allows the orthodontic doctor, dental assistant, technician or other user (these terms are used interchangeably herein) to place two o-rings at the mouth on separate brackets, without having to return to the o-ring stick to replenish the o-ring after each previous o-ring is applied.  
           [0004]    2. Description of the Related Prior Art.  
           [0005]    Prior to the present invention, the orthodontist and the technicians or other dental assistants performing this procedure used ligature pliers having a conventional shape of two opposed plates (jaws) to grab an o-ring typically from an o-ring stick. The selected o-ring is pulled off the o-ring stick while clamped within the jaws of the ligature pliers, also known as a hemostat, to hold the o-ring until it is placed on a bracket, by stretching the o-ring over the bracket wings or posts. This required the technician to travel from the o-ring source, the ligature stick, to the patient&#39;s mouth once for each o-ring used on a bracket.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention is an improved ligature pliers and method to allow the orthodontist or other user, to grab and secure two o-rings at a time with the ligature pliers from an o-ring stick and then individually release the said secured o-rings from the ligature pliers, as the user attaches each individual o-ring to a bracket. These improvements allow placement of more than one o-ring, each on a respective bracket, before the user must return the ligature pliers to the elastic ligature source.  
           [0007]    These and other aspects and features of the invention are described in more detail below and are illustrated in the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Referring to the drawings which are made a part hereof this application,  
         [0009]    [0009]FIG. 1. is a side view of the present invention with the jaws in an open position.  
         [0010]    [0010]FIG. 2. is a side view of the present invention with the jaws in a closed position securing two elastic ligators within the jaws.  
         [0011]    [0011]FIG. 3. is a top view of the present invention without o-rings within the jaws.  
         [0012]    [0012]FIG. 4. is a bottom view of the present invention of FIG. 3.  
         [0013]    [0013]FIG. 5. is a rear view of the present invention.  
         [0014]    [0014]FIG. 6. is a front view of the present invention similar to FIG. 2, shown in a clamped position with two o-rings within the grasp of the jaws  19 ,  20  and  21 .  
         [0015]    [0015]FIG. 7 is a top view of an o-ring stick with eleven o-rings releasably attached to each side of the stick.  
         [0016]    [0016]FIG. 8 is a schematic view of tooth T, a bracket B, an archwire W and an o-ring  22 .  
         [0017]    [0017]FIG. 9. is a partial exploded view showing the special relationship of stick  24 , jaws  19 ,  20  and  21  and o-rings  22  and  23 .  
         [0018]    [0018]FIG. 10 is a partial exploded view of an alternate embodiment for jaw  19  and member  16 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]    Referring to FIG. 1, the orthodontic ligature pliers  10  of the present invention are shown in an open position. Pliers  10  have elongated handle members  11 ,  12  and  13  pivotally connected by pivot pin  14  at pivot area  15 . Handle members  16 ,  17  and  18  extend from pivot area  15  and form a first jaw  19 , a second jaw  20  and a third jaw  21 . Each said jaw  19 ,  20  and  21  has a generally flat serrated inner face surface. This surface increases the ability to grip an elastic o-ring. The inner surface of jaw  19  in the present invention is opposite and faces the inner surfaces of jaws  20  and  21 .  
         [0020]    Referring to FIG. 6, the ligature pliers  10  are in a clamped position holding two elastic ligatures. Inner face surface of jaw  20 , which contacts a first o-ring  23 , is opposite a portion of the inner face surface of jaw  19  which also contacts o-ring  23 . Likewise, the inner face surface of jaw  21 , contacts a second o-ring  22 , is opposite a portion of the inner face surface of jaw  19  which also contacts o-ring  22 . Jaws  19 ,  20  and  21  are constructed and arranged such that in a clamped position, jaw  19  will contact and grip two o-rings  22  and  23 , in combination with jaw  20  which contacts and grips said o-ring  23 , and jaw  21  will contact and grip the other said o-ring  22 . Further, each o-ring can be gripped and then subsequently released independently of the other gripped o-ring. This independent operation is a result of the arrangement of handle member  11  on one side opposite handle members  12  and  13  such that said handle members  12  and  13  and their associated jaws  19 ,  20  and  21 , operate independently of one another.  
         [0021]    In the orthodontic practice, elastic ligatures  22  and  23 , see FIG. 8, are manufactured for orthodontic use whereby each o-ring is separately and individually attached to an elongated ligature stick  24  commonly called an elastic ligature stick or o-ring stick, see FIG. 7. Ligature stick  24  includes a base portion  25  and an elongated portion  26 . Individual O-rings e.g. o-ring  22  and o-ring  23 , are attached on both sides of elongated portion  26  in a side by side arrangement. The o-rings are releasable because the attachment portion  26   a  is designed to break-off, such that each o-ring can be detached from elongated portion  26 , preferably at the point where  26   a  attaches to the outer circumference of each individual o-ring.  
         [0022]    In the present invention, any two of said o-rings that are side by side e.g. o-rings  22  and  23 , using the present invention, can be gripped and removed from ligature stick  24  by said ligature pliers  10  as shown in FIG. 6.  
         [0023]    Ligature pliers  10  include three lever arms pivoted together. A first lever arm  10   a  with handle member  11  at one end and member  16  at its other end, pivoted about pivot  15 . Like-wise a second lever arm  10   b  with handle member  12  at one end and member  17  at its other end, is pivoted about pivot  15 . A third lever arm  10   c  with handle member  13  at one end and member  18  at its other end, is pivoted about pivot  15 . Said first lever arm  10   a , said second lever arm  10   b  and said third lever arm  10   c , with corresponding handles  11 ,  12  and  13  and members  16 ,  17  and  18 , each pivot independently about pivot pin  14 . Handle  11  of lever arm  10   a  is on one side and handles  12  and  13  of lever arms  10   b  and  10   c  are on the opposite side. Likewise, member  16  is opposite of members  17  and  18 . Handles  12  and  13  and corresponding members  17  and  18 , both opposite handle  11  and member  16  respectively, operate independently, such that jaw  19  of member  16  can engage jaws  20  and  21  of members  17  and  18  at the same time. Likewise jaw  19  can engage jaw  21  and not jaw  20 . And as explained herein, jaw  19  will not engage either said jaws  20  and  21 , when both said jaws  20  and  21  are released.  
         [0024]    Therefore, two o-rings can be held and released independently of one another, such that in use the user will use ligature pliers  10  to simultaneously remove two o-rings from ligature stick  24  as set forth above. With ligature pliers  10  in an open first position, two o-rings  22  and  23  can be grabbed as follows: in the second position, o-ring  22  is grasped at its edge, near the outside circumference and held by jaw  19  and jaw  21 , and at the same time, o-ring  23  is similarly grasped and held by jaw  19  and jaw  20 . It can be noted that the width of jaw  19  must be sufficiently wide to contact two spaced apart o-rings attached to ligature stick  24 . Likewise jaws  20  and  21  are spaced apart a sufficient distance to allow each said jaws  20  and  21  to independently contact and grip a separate o-ring.  
         [0025]    In the second position, the user squeezes and moves handle  11  toward handles  12  and  13  so as to cause respective jaws  19  on one side and jaws  20  and  21  on the other side to grasp two o-rings  22  and  23 .  
         [0026]    In the third position, o-ring  22  is released independently, by operation of handle  13  operating independent of handle  12 .  
         [0027]    In the fourth position o-ring  23  is released by operation of handle  12 .  
         [0028]    By way of a background, the base of each handle  12  and  13  interact with the base of handle  11  by a separate ratchet means. The ratchet means used in the present invention allows a first handle and a second handle to close from an open to a closed position relative to and in relationship to a third handle.  
         [0029]    Ratchet teeth on the first handle engage ratchet teeth on the third handle and ratchet teeth on the second handle engage teeth on the third handle to allow closing of the first and second handles relative to the third handle to be ratcheted together in a fixed relationship without exertion or additional closing pressure, while an operation is performed by the user of attaching an o-ring to a bracket. Thereafter, additional closing pressure on the first and second handles allow the ratcheted portions to pass one another to allow the first and third handles to release and return to an open position relative to one another, while maintaining the closed relationship of the second handle with the third handle while another said operation is performed by the user. Thereafter the additional closing pressure on the second and third handles allow the ratcheted portions to pass one another and return to an open position relative to one another.  
         [0030]    Referring to FIG. 5, a novel part of the present invention, handle  13  is the first handle as heretofore described and handle  12  is the second handle, both said handles in relation to a third handle  11 . In this arrangement, handles  12  and  13  operate independently of one another. Additionally, the interaction of ratchet combination of handles  11  and  13  release earlier than the interaction of combination of ratchets of handles  11  and  12 . In this manner, in the second position, as previously described, two o-rings  22  and  23  are clamped as shown in FIG. 6, continued closing pressure applied by the user will cause the o-ring  22  gripped by handles  11  and  13  to release first, the third position. This allows the orthodontist to apply o-ring  22  to a first bracket and then release said o-ring  22  while maintaining the grip on o-ring  23  held by handles  11  and  12 . In the fourth position, O-ring  23  is then applied to a bracket and then said handles  11  and  12  are further closed and then released relative to one another when the ratchets of handles  11  and  12  pass each other to be released and subsequently release o-ring  23 . At this point the pliers  10  are open, in the first position as shown in FIG. 1, ready to repeat the cycle and grab two more o-rings.  
         [0031]    Referring to FIGS. 1 and 5, at base  27  of handle  11 , are two generally opposed ratchet portions  28  on one side and  29  on the other side. Base  30  of handle  12  has a ratchet portion  31 . Likewise base  32  of handle  13  has ratchet portion  33 . Spring means  34  is rigidly attached to the inside portion of handle  11  by nut  35  at one end. The other end of spring  34  has two ends, a first end slideably attached to the inside of handle  12  by nut  36  and a second end slideably attached to the inside of handle  13  (not shown). Spring  34  independently biases each handle  12  and  13  away from handle  11 . This spring  34  bias acts against the closing pressure, by the user, when handles  12  and  13  are closed against handle  11  and spring  34  asserts the pressure to maintain the ratchet portions  31  and  28 , and  29  and  33  in locked ratcheted positions until released.  
         [0032]    In use, an orthodontist will typically apply approximately 20 new o-rings to a patient&#39;s brackets when both the upper and lower arch wires are replaced. When using the present invention, pliers  10  are used to secure two o-rings at a time from stick  24 . It is also possible to secure or clamp only one o-ring if desired. Pliers  10  are placed perpendicular to elongated portion  26  putting jaw  19  to be in a position to clamp a first and second o-ring  22  and  23 , such that jaw  21  clamps said first o-ring  22  on the opposite side of jaw  19  and jaw  20  clamps said second o-ring  23  on the opposite side of jaw  19 . Handles  12  and  13  are squeezed and closed by the user toward handle  11  until all handles are in a first ratcheted position such that ratchet portions  29  and  33  are interlocked and ratchet portions  28  and  31  are interlocked. In this first ratcheted position, both o-rings  22  and  23  are securely clamped such that, pliers  10  grip o-rings  22  and  23  sufficiently strong enough to remove o-rings  22  and  23  from stick  24 . As shown in FIG. 8, jaws  19  and  20  and jaws  19  and  21  grab an edge portion of o-rings  23  and  22  respectively leaving sufficient room to apply o-rings  23  and  22  to a bracket (FIG. 9).  
         [0033]    After the o-rings are detached from the stick  24 , both o-rings are clamped, then the orthodontist moves ligature pliers  10  from the stick  26  to the patient&#39;s mouth to apply the first o-ring  22  to a bracket. This is done in a customary manner as known in the art. Then the handles  12  and  13  are closed against handle  11  until handles  11  and  13  release—the ratcheted portions  29  and  30  pass one another—thus releasing the first o-ring  22 . However, because the ratchet positions of handles  11  and  13  differ from the ratcheted positions of handles  11  and  12 , such that just when the ratcheted portions of handles  11  and  13  release, the ratcheted portion of handles  11  and  12  remain ratcheted. In this second ratcheted position, the second o-ring  23  remains gripped so that second o-ring can now be placed on another bracket while keeping pliers  10  in the vicinity of the patient&#39;s mouth and without the necessity of the orthodontist or other user returning ligature pliers  10  to the ligature stick  24  to attach another o-ring. The second o-ring is attached to a desired bracket and handles  11  and  12  are squeezed and closed until the ratchet sections  28  and  31  release from one another. At this position the pliers are in an open position biased by spring  34  and are ready to repeat the cycle again of attaching two more o-rings, but having reduced the orthodontist&#39;s travel time from patient&#39;s mouth to o-ring stick  24  by approximately one half.  
         [0034]    In maintaining the spirit of this invention, the beak area of jaws  19 ,  20  and  21  can assume different shapes, including that jaw  19 , can have two beak portions  19   a  and  19   b , shown in FIG. 10, instead of a single beak portion jaw  19 . Each said beak portion would rigidly form member  16  attached to handle  11 . One said portion  19   a  would line up opposite jaw  21  and the other portion  19   b  would line up opposite jaw  20 . Additionally it is anticipated that handle  13  would appear in some manner different than handle  12  such that the user could easily identify the handle that would release the first o-ring. Each of the handles can be of a different color or other identifying means such as grip markings or modified surface markings and surfaces could also be used within the scope of the present invention to separately indicate handles  11 ,  12  and  13  from one another.  
         [0035]    Although the disclosure set out herein is detailed in order to enable those skilled in the art to practice the invention, the embodiments disclosed herein are to be considered only examples of the invention which may be embodied in other specific structures as well.  
         [0036]    Those skilled in the art will recognize that a number of other modifications to the invention are also possible. Accordingly, the invention should not be deemed limited to the specific embodiments described hereinabove and illustrated in the drawings, but instead only by a fair scope of the claims that follow along with their equivalents.