Abstract:
An improved dental forceps has a pair of gripping distal tips for placing and removing articles such as metal bands, strips, and soft cotton pellets on and from teeth. A plane of orientation is defined by the longitudinal axes of two elongated legs which are biased apart from each other at one end when the legs are not being squeezed. At the end of each leg is a gripping distal tip, with both distal tips deviating at an angle from the legs&#39; longitudinal axes toward the outside surface of one leg and away from the outside surface of the other leg, while staying approximately within the forceps&#39; plane of orientation. Due to this planar orientation of the distal tips, less twisting of the wrist is necessary while using the forceps, thereby reducing the risk of radio-carpal conditions, especially after long periods of use. The distal tip of each leg has a curved inside surface such that the gripping space is formed between the surfaces when the legs are not being squeezed. Since the direction of forceps gripping is parallel to the forceps&#39; plane of orientation, the major line of the gripping action is approximately contained across this plane. When the practitioner squeezes the forceps, the curled, inside edges of the distal tips exert a gripping action that produces a longitudinal or sliding motion between the distal tips as the practitioner varies the tightness of the squeezing action. The ability to effect this motion tends to increase sensitivity and fine control in gripping.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 60/266,783 filed on Feb. 6, 2001, which is incorporated herein by reference. 
     
    
     
       BACKGROUND  
         [0002]    This invention relates to the field of dental forceps, such as those used by dental professionals, for use in dental procedures. More specifically, this invention relates to forceps useful for the placement and removal of articles such as metal bands, strips, and soft cotton pellets on and from teeth.  
           [0003]    There are many types of forceps available to dental practitioners that are useful in performing various types of dental procedures. However, many of these devices compromise dexterity and comfort for the user, who is normally a dental practitioner. Forceps are normally comprised of two squeezed members or legs which define a plane of orientation. Previous forceps have included distal tips positioned at approximately 45° angles from this plane of orientation. Due to the geometries associated with a patient&#39;s mouth and jaw, such previous devices often require awkward positioning of the practitioner&#39;s hand and wrist. In such circumstances, it is common for a practitioner&#39;s wrist to be turned as much as 90° from its relaxed position. Depending on the particular procedure involved, it may be necessary for the practitioner to maintain this awkward positioning for extended periods.  
           [0004]    It is commonly known that repetitive tasks performed at deviations from relaxed anatomical positions can result in fatigue, discomfort, and possible carpal syndromes ultimately requiring medical attention and treatment. However, previous forceps designs have been limited in that they cannot be used properly without subjecting practitioners to such awkward arm and wrist positioning. It follows that such instruments pose a continued potential for physical injury to their users, especially after extended or repeated use. Awkward arm and wrist positioning also tends to obstruct the practitioner&#39;s visual field, further complicating various dental procedures.  
           [0005]    Some previous designs have attempted to reduce the amount of gripping required by having a construction that makes them self-closing. In these designs, the resiliency of the interconnection between the separate legs biases the forceps in their closed position. Such designs are arranged so that external pressure applied to the forceps by squeezing the legs together at a point near the point of interconnection serves to draw the distal tips apart from each other, thereby releasing gripping action of the tips&#39; inside surfaces. However, such configurations are significantly limited in the amount of gripping force that can be exerted by the forceps legs, such force being restricted to the biasing force of the legs&#39; interconnection. It is not possible for a practitioner to increase the gripping force of such forceps by squeezing harder or by applying additional pressure. This can prove to be a significant problem in certain situations. For example, during the placement of an interproximal strip or band in tight contact, the strip or band can slip out of the distal tips, making the procedure difficult for the practitioner. Moreover, while such designs may reduce the amount of positive gripping force required to perform a gripping operation, or while such designs may shorten the duration of the required manual squeezing, they do not eliminate the need for the practitioner to at least momentarily and repeatedly position the hand in an awkward position.  
           [0006]    Previous forceps have been further limited by the fact that the relative positioning of their distal tips remains constant when closed. In most previous designs, squeezing the forceps forces the inside portions of each leg to meet at a particular gripping surface near the legs&#39; distal tips. Once the gripping surfaces meet, neither of the distal tips slide relative to the other regardless of the amount of force the practitioner applies. If the practitioner squeezes harder, a tighter grip may or may not result, but there will be no additional relative movement between the gripping surfaces. Accordingly, there will be no improvement in the practitioner&#39;s tactile sensitivity and control. This limitation can also make it difficult for the practitioner to fully manipulate certain dental elements to be positioned in the tight confines of a patient&#39;s mouth. In addition, excessive squeezing pressure against the legs can force the distal tips apart, resulting in reduced gripping force and the loss of tactile control of gripped objects.  
         SUMMARY  
         [0007]    The present invention is an improved dental forceps having a pair of gripping distal tips for placing and removing articles such as metal bands, strips, and soft cotton pellets on and from teeth. It is an object of the invention to reduce fatigue, discomfort, carpal syndromes, and other adverse physical effects associated with prolonged or repetitive dental procedures that require a practitioner to orient the hand in an awkward or deviated position. In allowing for the less awkward orientation of a practitioner&#39;s arm and wrist, it is also an object of the invention to increase a practitioner&#39;s visual field during use.  
           [0008]    The invention includes two elongated legs in springing connection at one end and biased apart from each other so that a gripping space exists between the other end of the legs when the legs are not being squeezed. A plane of orientation is defined by the longitudinal axes of the two legs. At the end of each leg is a gripping distal tip, with both distal tips deviating at an angle from the legs&#39; longitudinal axes toward the outside surface of one leg and away from the outside surface of the other leg, while staying approximately within the forceps&#39; plane of orientation. Due to this planar orientation of the distal tips, less twisting of the wrist is necessary while using the forceps, thereby reducing the risk of radio-carpal conditions, especially after long periods of use.  
           [0009]    The distal tip of each leg has a curved inside surface such that the gripping space is formed between the surfaces when the legs are not being squeezed. Since the direction of forceps gripping is parallel to the forceps&#39; plane of orientation, the major line of the gripping action is approximately contained across this plane. When the practitioner squeezes the forceps, the curled, inside edges of the distal tips exert a gripping action that produces a longitudinal or sliding motion between the distal tips as the practitioner varies the tightness of the squeezing action. The ability to effect this motion tends to increase sensitivity and fine control in gripping.  
           [0010]    The invention also includes a self-locking mechanism on the inside surfaces of the legs of the forceps. The self-locking mechanism is configured to engage and lock the forceps in a closed position after the practitioner squeezes the forceps fully. The self-locking mechanism maintains the forceps in the closed position until the practitioner manually releases the mechanism.  
           [0011]    Various other features, advantages, and characteristics of the present invention will become apparent to one of ordinary skill in the art after reading the following specification. This invention does not reside in any one of the features of the forceps disclosed above and in the following Detailed Description of the Preferred Embodiments and claimed below. Rather, this invention is distinguished from the prior art by its particular combination of features which are disclosed. Important features of this invention have been described below and shown in the drawings to illustrate the best mode contemplated to date of carrying out this invention.  
           [0012]    Those skilled in the art will realize that this invention is capable of embodiments which are different from those shown and described below and that the details of the structure of this automatic lock can be changed in various manners without departing from the scope of this invention. Accordingly, the drawings and description below are to be regarded as illustrative in nature and are not to restrict the scope of this invention. The claims are to be regarded as including such equivalent automatic locks as do not depart from the spirit and scope of this invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    For a more complete understanding and appreciation of this invention and many of its advantages, reference should be made to the following, detailed description taken in conjunction with the accompanying drawings wherein:  
         [0014]    [0014]FIG. 1 is a perspective view of a typical dental forceps according to the invention, depicting distal tips angled approximately within the legs&#39; plane of orientation and having a single piece locking mechanism;  
         [0015]    [0015]FIG. 2 is a perspective view, for comparison with the novel forceps of FIG. 1, of prior dental forceps depicting distal tips angled away from the legs&#39; plane of orientation;  
         [0016]    [0016]FIG. 3 is a perspective view of an embodiment of the invention having a pawl locking mechanism;  
         [0017]    [0017]FIG. 4 is a perspective view of an embodiment of the invention having a sliding block locking mechanism;  
         [0018]    [0018]FIG. 5 is a top view of the dental forceps of FIG. 4 showing the profile of the apparatus being contained within the legs&#39; plane of orientation;  
         [0019]    [0019]FIG. 6 is a cross sectional side view of the forceps of FIG. 4 showing angled distal ends of each leg and also showing the assembled components of the sliding block locking mechanism according to one embodiment of the invention;  
         [0020]    [0020]FIG. 7 is an exploded, perspective view of the forceps of FIG. 4 further representing the individual components of the sliding block locking mechanism according to one particular embodiment of the invention;  
         [0021]    [0021]FIG. 8A is side view of the forceps of FIG. 7 depicting the outside surfaces of the legs being squeezed so that the curled inside edges of the distal tips begin to contact each other, the sliding block locking mechanism being disengaged;  
         [0022]    [0022]FIG. 8B represents the same view of the forceps depicted in FIG. 8A after additional pressure has been applied by the practitioner&#39;s squeezing so that the inside curled surface of the distal tip of the first leg begins to push the inside curled surface of the distal tip of the second leg outward, the sliding locking mechanism being disengaged;  
         [0023]    [0023]FIG. 8C represents the same view of the forceps depicted in FIG. 8B after still additional pressure has been applied by the practitioner&#39;s squeezing so that the forceps are fully closed and so that the inside curled surface of the distal tip of the first leg pushes the inside curled surface of the distal tip of the second leg fully outward, the sliding block locking mechanism being disengaged;  
         [0024]    [0024]FIG. 8D represents the same view of the forceps depicted in FIG. 8C with the forceps being fully closed, the sliding block locking mechanism being engaged;  
         [0025]    [0025]FIG. 9 depicts a dental forceps of the invention in which the distal tips are positioned at an angle that is opposite to the positioning of the distal tips in FIG. 1;  
         [0026]    [0026]FIG. 10 depicts a dental forceps of the invention having a spring arm of a single piece locking mechanism mounted on the second leg of the forceps;  
         [0027]    [0027]FIG. 11 is a perspective view of a dental forceps of the invention having a pawl of a pawl locking mechanism mounted on the forceps&#39; second leg and biased to rotate toward the first ends of the forceps&#39; legs;  
         [0028]    [0028]FIG. 12 depicts a forceps of the invention having a pawl of a pawl locking mechanism mounted on the forceps&#39; first leg and biased to rotate toward the first ends of the forceps&#39; legs;  
         [0029]    [0029]FIG. 13 depicts a forceps of the invention having a pawl of a pawl locking mechanism mounted on the forceps&#39; first leg and biased to rotate toward the second ends of the forceps&#39; legs;  
         [0030]    [0030]FIG. 14 is a perspective view of a dental forceps of the invention having a single transverse notch extending along the width of the distal tip on the forceps&#39; second leg;  
         [0031]    [0031]FIG. 15 is a magnified view of the forceps of FIG. 14 depicting the forceps in their closed position, the forceps&#39; distal tips gripping an object at the forceps&#39; transverse notch; and  
         [0032]    [0032]FIG. 16 is a magnified view of a forceps of the invention having a transverse notch extending along the width of the distal tip on the forceps&#39; first leg. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    Referring to the drawings, identical reference numbers designate the same or corresponding parts throughout the several figures shown in the drawings.  
         [0034]    [0034]FIG. 1 depicts a pair of forceps  10  according to the invention having a first leg  12  and a second leg  14 . The first leg  12  includes a first leg end  16  and a second leg end  18 , and also includes an inside surface  15  and an outside surface  17 . The second leg  14  includes a first leg end  20  and a second leg end  22 , an inside surface  19 , and an outside surface  21 . FIG. 1 shows that the first leg  12  has an elongated major dimension  24  and the second leg  14  has an elongated major dimension  26  so that the major dimensions  24  and  26  define a longitudinal axis for legs  12  and  14 , respectively. The axes of legs  12  and  14  meet at a point of springing interconnection  28  at a slight angle so that the second leg ends  18  and  22  are biased apart from each other leaving a gripping space  30 . Any means of connection, such as a rivet, weld, or solid structuring can be used to join the first leg ends  16  and  20  so long as each of the second ends  18  and  22  remain springingly biased apart with a relative positioning that leaves a gripping space  30  between them.  
         [0035]    The legs  12  and  14  may be constructed of any number of flexible materials. Generally, the material used will permit appropriate casting or molding of either the entire forceps apparatus or of the individual connectable components of the forceps assembly. In most cases, the material used will also be able to withstand high temperatures associated with sterilization or disinfecting processes as required for intrusive medical instruments. Such materials may include but are not limited to various metals and plastics or other polymers or synthetic materials. Materials having elastomeric properties may also be incorporated into the design to improve gripping comfort.  
         [0036]    The longitudinal axes  24  and  26  defined by the major dimensions of first leg  12  and second leg  14  form a slight angle between the legs  12  and  14  extending from the point of springing interconnection  28 . This angle formed by the axes defines a plane of orientation to which each of the legs  12  and  14  is substantially restricted. First gripping distal tip  32  and second gripping distal tip  34  extend, respectively, from each of the second leg ends  18  and  22  at an angle from each leg&#39;s respective longitudinal axis  24  or  26  but within the plane of orientation of the two legs. Thus, the distal tips  32  and  34  are oriented at an angle away from the outside surface  21  of the second leg  14  and toward the outside surface  17  of the first leg  12 , creating a first curled inside surface  36  of distal tips  32  and a second curled inside surface  38  of distal tip  34  that face each other. The relative positioning of the curled inside surfaces  36  and  38  is best understood by comparing the perspective view of FIG. 1 with the top and side views of the forceps  10  of this invention shown in FIG. 5 and FIG. 6.  
         [0037]    The positioning of the distal tips&#39; curled inside surfaces  36  and  38  with respect to one another permits the tips  32  and  34  to exert gripping forces when external pressure is applied simultaneously to each of the legs  12  and  14 . First leg  12  has an outside planar surface  42  and second leg  14  has an outside planar surface  40  to allow for squeezing against the biasing force of the springing interconnection  28 . The planar surfaces  40  or  42  may be textured (as shown) in order to allow the practitioner to exert a tighter or more precise grip while squeezing. While the embodiment depicted in FIG. 1 shows a forceps  10  having this texturing as part of the formed planar surfaces  40  and  42 , it will be appreciated that in some embodiments, the texturing can also be comprised of separate material elements attached directly to the planar surfaces  40  and  42 . Such elements may appropriately comprise plastic, rubber, or similar composite materials.  
         [0038]    When squeezed, pressure exerted against the legs  12  and  14  tends to move the inside surfaces  36  and  38  inward within the gripping space  30  so that a gripped object contacts the curled inside surfaces  36  and  38  directly. The downward squeezing motion of the legs  12  and  14  and angled positioning of the distal tips  32  and  34  permit the practitioner to operate the forceps  10  while maintaining the hand in a more comfortable and natural position. It is not necessary to unduly twist the wrist or fingers into an awkward or unnatural position for an extended period.  
         [0039]    The relative orientation of the distal tips  32  and  34  allows for distinct structural and operational advantages which can be best understood by comparison with forceps of the prior art. FIG. 2 depicts a typical pair of prior art forceps  44  having a first leg  46  and a second leg  48  biased into an open position at a point of springing interconnection  50 . In such previous designs, the first leg  46  has a major dimension  52  and the second leg  48  has a major dimension  54 , the respective major dimension  52  and  54  defining longitudinal axes which interconnect at an angle at the point of springing interconnection  50  and which define a plane of orientation. The first leg  46  also ends in a distal tip  56  and the second leg  48  ends in a distal tip  58 . However, unlike the distal tips  32  and  34  of forceps  10  of this invention, the distal tips  56  and  58  of prior art forceps  44  bend away from the plane of orientation while gripping objects in gripping space  60 . As a result, the practitioner&#39;s wrist must be bent at an awkward angle to align fingers into a squeezing position while positioning distal tips  32  and  34  to a similar orientation.  
         [0040]    Other advantages of the invention relate to improved sensitivity while manipulating gripped objects. Unlike previous forceps such as those depicted in FIG. 2, a novel feature of the invention permits the distal tips  32  and  34  to move longitudinally or to slide, with respect to each other depending on the amount of pressure with which the practitioner squeezes, allowing for enhanced precision during use. To understand this operation, reference should first be made to FIG. 1 for comparison with FIGS.  8 A-D. FIG. 1 depicts a pair of open forceps  10  that are not subjected to external pressure from squeezing and which are biased in their open position.  
         [0041]    Referring now to FIG. 8A, an alternative embodiment of the forceps  10  are depicted while being squeezed slightly so that the curled inside surfaces  36  and  38  of the gripping distal tips  32  and  34  make slight contact. The distal tip  34  of the second leg  14  has not yet moved along the leg&#39;s longitudinal axis  26  with respect to the distal tip  32  of the first leg  12 .  
         [0042]    Depending on the object being manipulated, the practitioner may wish to exert additional pressure by squeezing harder at planar surfaces  40  and  42  against the biasing force on legs  12  and  14 . FIG. 8B depicts the effect of a slight increase in the squeezing force that the practitioner exerts against the legs  12  and  14 . As a result of the additional pressure, the distal tip  34  of the second leg  14  pushes downward against the distal tip  32  of the first leg  12 , forcing the distal tip  34  of the second leg  14  to slide outward along the leg&#39;s longitudinal axis  26 . This sliding motion results in a slight springlike bending of the second leg  14 , the extent of which is dependent on the amount of pressure the practitioner exerts against the legs  12  and  14 . As the distal tip  34  of the leg  14  slides over the distal tip  32  of the first leg  12 , the practitioner is able to adjust the tactile sensitivity of the gripping motion as necessary without substantially reducing the gripping force exerted.  
         [0043]    As the practitioner continues to squeeze with additional force, the distal tip  34  of the leg  14  continues to slide over the distal tip  32  of the first leg  12  until it is fully extended as shown in FIG. 8C. At this point, the practitioner can continue adjusting the gripping force by reducing the squeeze exerted against the legs  12  and  14 , thereby permitting the springing action of the second leg  14  and the biasing force of the springing interconnection  28  to retract the distal tip  34  with respect to the distal tip  32 .  
         [0044]    The forceps of this invention can be used as described above without a lock. Alternatively, the illustrated embodiments of the invention allow the practitioner to lock the forceps  10  so that they will remain closed when the practitioner releases the squeezing action entirely. The invention presents additional advantages due to some inherent characteristics of its design. These advantages are best understood when compared to previous designs such as the forceps  44  depicted in FIG. 2. The prior art forceps  44  include a first leg  46  having a leg end  64  and a distal end  56  and a second leg  48  having a leg end  66  and a distal end  58 . A single-piece locking mechanism  62  includes a locking head  61  positioned at the end of a spring arm  63  extending from the second leg  48 , and a locking hole  65  extending through the first leg  46 .  
         [0045]    The prior art forceps leg ends  64  and  66  are configured so that when a practitioner fully squeezes prior art forceps legs  48  and  46 , the first distal end  56  and second distal end  58  exert their gripping force against objects located within gripping space  60 . At this point, the locking head  61  enters and locks inside of the locking hole  65 , locking the forceps  44  in the closed position. However, since the inside surfaces of the distal ends  56  and  58  are substantially parallel with the adjacent inside surfaces of the legs  48  and  46 , gripping forces tend to be exerted most tightly at a rolling fulcrum point between the first leg end  64  and second leg end  66 , particularly if the locking mechanism  62  engages or if the practitioner squeezes the legs  46  and  48  tightly. If the practitioner exerts additional pressure, the effect of the rolling fulcrum between the leg ends  64  and  66  tends to force the outermost end  68  of distal tip  56  and outermost end  70  of distal tip  58  away from each other. As a result, slight clearances can exist between the distal tips  56  and  58 , especially near the outermost ends  68  and  70 . Such clearances can reduce the ability of the forceps to grasp smaller diameter items such as dental floss or articulating film.  
         [0046]    A similar single piece locking mechanism can also be incorporated into the invention as depicted in the embodiment in FIG. 1. The locking mechanism  69  includes a locking head  71  having an undercut  77  and positioned at the end of a spring arm  73  extending from the inside surface  15  of the first leg  12 . A locking hole  75  having an engagement edge  79  extends through the second leg  14 . The locking head  71  is positioned so that when a practitioner fully squeezes the forceps legs  12  and  14 , the locking head  71  contacts the inside surface  19  of the second leg  14 , compressing the spring arm  69  which flexibly slides the locking head  71  toward the legs&#39; second ends  18  and  22 . This sliding motion of the locking head  71  allows the head&#39;s undercut  77  to clear the engagement edge  79  of the locking hole  75  to permit the locking head  71  to pass into the locking hole  75  under the compression force of the spring arm  73 . When a practitioner releases squeezing pressure against the legs  12  and  14 , the compression force of the spring arm  73  is also released. However, the undercut  77  of the locking head  71  catches against the engagement edge  79  of the locking hole  75 , locking the forceps  10  in the locked position. When the forceps  10  are locked, much of the locking head  71  remains above the planar surface  40  of the second leg  14 . While handling the forceps  10  at the planar surfaces  40  and  42 , the practitioner can easily unlock the forceps  10  by sliding one finger forward against the exposed undercut  77  of the locking head  71  so that the undercut  77  again clears the engagement edge  79  and the locking head  71  passes through the locking hole  75 .  
         [0047]    It will be appreciated that such a locking mechanism  69  could be affixed to the forceps  10  of the invention in alternate ways. For example, the locking mechanism  69  could be arranged so that the spring arm  73  and locking head  71  extend from the second leg  14 . In such an embodiment, as depicted in FIG. 10, the locking hole  75  is positioned on the first leg  12 .  
         [0048]    Other locking mechanisms can also be used with the forceps  10 . Referring to FIG. 3, one alternate embodiment of the invention includes a pawl locking mechanism  99  having a spring-operated pawl  81  that is mounted on a pivot  83  on the second leg  14  of the forceps  10 . The pawl  81  has a tapered release surface  85  which extends through an operating space  87  in the second leg  14  and which is adjacent to the second leg&#39;s outside planar surface  40 . A locking hole  91  having an engagement edge  93  extends through the first leg  12 . The pawl  81  is biased with a spring  103  to rotate on its pivot  83  in a direction that is generally toward the second ends  18  and  22  of the legs  12  and  14 . When fully rotated in this direction, the pawl assumes a biased position (shown in FIG. 3). It will be appreciated that the spring  103  can have a circular, leaf spring, or other construction so long as the pawl is spring biased to a biased position. The pawl  81  also includes a tapered end  95  and an undercut  97  for locking the forceps  10  after the forceps  10  are squeezed fully.  
         [0049]    As the practitioner squeezes the forceps  10 , the pawl  81  begins to contact the engagement edge  93  of the locking hole  91  at the pawl&#39;s tapered end  95 . The angled shape of the tapered end  95  causes the pawl  81  to rotate on its pivot  83  as the practitioner applies progressive amounts of squeezing force. This rotational movement is against the biasing force of the pawl&#39;s spring  103 . When the practitioner squeezes the forceps  10  fully, the pawl  81  rotates sufficiently to clear the engagement edge  93  and the pawl  81  enters the locking hole  91 . Once the pawl  81  has entered the locking hole  91 , the biasing force of the pawl&#39;s spring  103  pushes the undercut  97  of the pawl  81  under the engagement edge  93 , securing the forceps  10  in their locked position.  
         [0050]    To unlock the forceps  10  using this pawl locking mechanism  99 , the practitioner need only extend one finger from the second leg&#39;s planar surface  40  to the tapered release surface  85 . This can normally be done with a single finger stroke and without releasing the practitioner&#39;s grip due to the proximity of the second leg&#39;s planar surface  40  to the release surface  85  of the pawl. In pressing the release surface  85 , the practitioner rotates the pawl  81  on its pivot  83  against the biasing force of the pawl&#39;s spring  103 , allowing the pawl&#39;s undercut  97  to clear the engagement edge  93  and pass out of the locking hole  91 , unlocking the forceps  10 .  
         [0051]    It will be appreciated that a pawl locking mechanism  99  can also be affixed to the forceps  10  of the invention in alternate ways. Referring to FIG. 11, the pawl locking mechanism  99  could be arranged so that the pawl  81  is biased to rotate away from the second ends  18  and  22  and toward the first ends  16  and  20  of the legs  12  and  14 . In this embodiment, the undercut  97  of the pawl  81  would be positioned to extend away from the second ends  18  and  22  and toward the first ends  16  and  20 . In pressing the tapered release surface  85 , the practitioner rotates the pawl  81  toward the legs&#39; second ends  18  and  22  to clear the engagement edge  93  and unlock the forceps  10 . FIGS. 12 and 13 also depict embodiments having pawl locking mechanisms  99  similar to the embodiments depicted in FIG. 3 and FIG. 11, but each having its pawl  81  pivotally mounted to the first leg  12  of its respective forceps  10 . In each of these embodiments, the locking hole  91  extends through the second leg  40  of the forceps  10 . The pawl  81  is thus released by extending the practitioner&#39;s fingers from the first leg&#39;s planar surface  42  to the tapered release surfaces  85 .  
         [0052]    Another possible locking mechanism incorporates the use of a spring-loaded, sliding block. This sliding block locking mechanism  72  contemplated by the invention includes a spring-loaded locking block  74  that is inserted to slide axially, or back and forth along the first leg&#39;s longitudinal axis, into a lock slot  76 . Additional detail of the mechanism&#39;s construction and operation is best understood with reference to the exploded view of the sliding block locking mechanism  72  in FIG. 7. The locking block  74  includes twin engagement flanges  78  for securing the locking block  74  in the lock slot  76  and an end stop  80  for restricting retraction of the locking block  74  against a compression spring  82 . An alignment post  84  extends from the inside surface  19  of the second leg  14  so that during compression of the legs  12  and  14 , the alignment post  84  extends through an alignment hole  86  in the first leg  12 . The alignment post  84  includes an undercut  88  for engaging a locking surface  90  on the locking block  74 . The undercut  88  has an inclined surface  89  for engaging and compressing the locking block  74  against the compression spring  82  and for automatically locking the forceps  10  into a locked position when the forceps  10  are fully compressed. Such a locked position is depicted in FIG. 8D. Once closed in the locked position, a contoured lower surface  92  on the locking block  74  permits the practitioner to compress the locking block  74  against the compression spring  82 , as shown in FIGS.  8 A-C, to release the gripping action of the forceps  10 .  
         [0053]    In some embodiments, such as the embodiment depicted in FIG. 9, the positioning of the sliding block locking mechanism  72  can be arranged so that the locking block  74  slides axially on the second leg  14  instead of the first leg  12  of the forceps  10 . In these embodiments, the alignment hole  86  also extends through the second leg  14  while the alignment post  84  extends from the inside surface  15  of the first leg  12 . Here, while the angular positioning of the distal tips  32  and  34  with respect to the sliding block locking mechanism  72  is opposite to the relative distal tip positioning in the embodiment of FIG. 4, it will be appreciated that either embodiment as well as other variations may be appropriately implemented without departing from the scope of this invention.  
         [0054]    It will also be appreciated that while the embodiments shown and described include various locking mechanisms, forceps having a other locking mechanisms or that lack any locking feature are also contemplated to be within the scope of the invention.  
         [0055]    The embodiments of the invention shown herein do not present the inter-distal tip clearance problems associated with previous designs such as the prior art forceps  44  of FIG. 2. As shown in FIG. 8A, when a practitioner exerts sufficient squeezing force to draw the gripping distal tips  32  together, the curled inside surfaces  36  and  38  initially make slight contact. As shown in FIG. 8B, additional pressure forces the distal tip  34  of the second leg  14  downward against the distal tip  32  of the first leg  12 , forcing the distal tip  34  of the second leg  14  to move longitudinally outward along the leg&#39;s longitudinal axis  26 . This has the effect of increasing the amount of rolled surface area in which the curled inside surfaces  36  and  38  may come into contact. As noted above, if the curled inside surfaces  36  and  38  touch, a larger amount of force causes the second leg&#39;s distal tip  34  to slide relative to the distal tip  32  of the first leg  12  until it is fully extended as shown in FIG. 8C. Thus, FIGS.  8 A-C demonstrate that additional squeezing pressure forces the curled inside surfaces  36  and  38  of the first leg  12  and second leg  14  to increase the amount of rolled surface area at which the legs  12  and  14  are in contact. This characteristic of the invention substantially reduces the effect of clearances between the distal tips  32  and  34  that might otherwise tend to result from the practitioner&#39;s excessive squeezing, from manipulation of the forceps  10  such as in FIGS.  8 A-C, or from placing the forceps  10  in their locked position such as in FIG. 8D.  
         [0056]    This characteristic also permits the invention to incorporate gripping notches into the forceps&#39; design. This is best understood by first referring to the prior art forceps  44  of FIG. 2. In such previous designs, a transverse notch  100  extends along the width and a longitudinal notch  102  extends along the length of each distal tip  56  and  58 . Each transverse notch  100  is opposite to a corresponding transverse notch  100  on the opposite distal tip  56  or  58 . When the forceps  44  are closed, the opposite transverse notches  100  form a larger surrounding notch, extending the width of the distal tips  56  and  58 . Each longitudinal notch  102  also has a corresponding longitudinal notch  102 . Together, the longitudinal notches  102  form a larger surrounding notch extending the length of the distal tips  56  and  58  when the forceps  44  are closed. The larger notches formed by the closed transverse notches  100  and longitudinal notches  102  permit the practitioner to exercise precise and rigid grasping of very thin dental elements such as pins and flosses. However, in order for proper gripping to occur, a gripped object must have an identical or larger sized diameter than the larger surrounding notch of the combined transverse notches  100  or longitudinal notches  102  and must also simultaneously fit into the lines of both opposing transverse notches  100  or of both opposing longitudinal notches  102 .  
         [0057]    For comparison with the prior art forceps  10  of FIG. 2, FIG. 14 depicts an embodiment of the invention having a single transverse notch  104  extending the width of the distal tip  34  of the second leg  14 . A magnified view of the distal tips  32  and  34  is depicted in FIG. 15, the distal tips  32  and  34  shown gripping the cylindrical section of a gripped object  106 . As shown in FIG. 15, the notch  104  can be sufficiently large to accommodate a substantial cross-sectional portion of a gripped object  106 . When the practitioner squeezes the legs  12  and  14  of the forceps  10 , the curled inside surface  36  of the of the first leg&#39;s distal tip  32  presses the gripped object  106  against the notch  104  in the second leg&#39;s distal tip  34 . Thus, unlike previous forceps, the forceps  10  of FIG. 15 require only that the object  106  be in line with and have the diameter of a single notch  104  in order to be gripped. As the distal tips  32  and  34  slide with respect to each other during the gripping action, the gripped object  106  is free to slide along the curled inside surface  36  of the first leg&#39;s distal tip  32  while the single notch  104  secures the gripped object  106  in position.  
         [0058]    While FIG. 15 depicts a forceps  10  having a notch  104  positioned on the distal tip  34  of the forceps&#39; second leg  14 , it will be appreciated that a similar, single notch  104  could be also be positioned in other locations and remain within the scope of the invention. For example, FIG. 16 is a magnified view of an alternate embodiment forceps  10  in which a single notch  104  extends across the width of the distal tip  32  of the forceps&#39; first leg  12 . In this embodiment, when the distal tips  32  and  34  slide with respect to each other during the gripping operation, the gripped object  106  slides across the curled inside surface  38  of the second leg&#39;s distal tip  34 , the object  106  being secured in place by the distal tip  32  of the forceps&#39; first leg  12 .  
         [0059]    Those skilled in the art will recognize that the various features of this invention described above can also be used in various combinations with other elements without departing from the scope of the invention. This invention has been explained with respect to the details, arrangements of components, and certain specific embodiments shown in the accompanying drawings. Many modifications can be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, the appended claims are intended to be interpreted to cover such equivalent dental forceps that do not depart from the spirit and scope of the invention.