Abstract:
A driving tool which slidingly penetrates and engages a rectangular socket formed in one end of a screw or the like. The screw is preferably a dental implant having a threaded and polygonal female socket. The tool has two opposed jaws dimensioned and configured to be received in close cooperation with the socket. The jaws are spaced apart by a gap and compress slightly as they penetrate the socket. The jaws frictionally and resiliently engage the socket, thus enabling the screw to be grasped, maneuvered, and rotatably threaded into place without requiring threaded engagement of tool and screw. The tool is slidably withdrawn after the screw is tightened.

Description:
REFERENCE TO RELATED APPLICATION  
       [0001]     This application is related to Ser. No. 10/244,006, filed Sep. 24, 2002. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to tools, and more particularly to a tool for grasping and driving a screw type device having a polygonal socket formed at one end for receiving a driving tool.  
         [0004]     2. Description of the Prior Art  
         [0005]     Fasteners and anchors bearing external screw threads are usually installed by rotatably driving them into engagement with a base or supporting stratum. Such fasteners and anchors, which will be referred to hereinafter collectively as screws regardless of their intended purposes, are usually provided with a head having structure for engaging a driving tool, and an elongated shaft which shaft is typically threaded. The shaft advances into the supporting stratum when it is rotated, and may be withdrawn by reversing the direction of rotation. The structure of the head which engages a driving tool may comprise a polygonal external surface at one end of the shaft, such as a hexagonal head or alternatively, a polygonal socket formed at the same end in the absence or in addition to a polygonal external surface. The present invention is concerned with the latter type, wherein the head has a polygonal recess or socket configured to receive a driving bit or blade of a driving tool.  
         [0006]     Driving tools typically have a bit or blade which is inserted into the socket and engages the socket by cooperation therewith, such as by abutment. Interference between the socket and the bit assures that the screw device will be driven when the tool is rotated. The tool of the present invention has not only a bit enabling driving of screw devices, but also grasping of the screw device. This ability is imparted by cooperating jaws or prongs which are initially spaced apart from one another and which compress resiliently as they penetrate and contact the socket of the screw. The jaws engage the walls of the socket by friction, assisted by spring action of resistance to further compression of the jaws.  
         [0007]     Being able to grasp the screw by a driving tool is very advantageous in miniaturized applications, such as the field of dental implants, eyeglass screws, and machine tool inserts, among others. In dentistry, implants and their various associated components are so small as to be very difficult to maneuver into place by hand. U.S. Pat. No. 5,105,690, issued to Lazarra et al. on Apr. 21, 1992, illustrates a driver tool intended for small dental implants. Manufacturing the driver tool of Lazarra et al. requires forming the bit in two sections of similar cross section, but different configurations as viewed in side elevation. The smaller section, which is not tapered, is a driving section, while the larger tapered section is that intended to engage the walls of a socket by friction.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention provides a screw grasping, maneuvering, and driving tool for screws such as fasteners, anchors, and other devices, which tool engages a polygonal socket formed in the head of the screw. The novel tool has at least two opposed jaws separated by a small gap. The jaws are configured to be received in the socket of the screw, having at least a portion of their external surfaces inclined or tapered to facilitate insertion. Insertion into the socket resiliently urges or compresses the jaws towards one another as progressively wider portions of the jaws enter the socket. The screw is then engaged and held by friction and by spring action of the compressed jaws. The tool may be used to transport the screw to its intended location, and to rotatably drive the screw home. Thus only one tool and uncomplicated manipulation of the tool enable the screw to be transported, set in place, and tightened in place.  
         [0009]     The novel arrangement of the jaws improves over the device of Lazarra et al., in that less effort is required to machine or otherwise fabricate the driving tool. Notably, in the present invention, the driving and grasping sections are integral with one another. This characteristic enables only one section to be formed during fabrication rather than two sections of different dimensions, as seen in the tool of Lazarra et al. Also, engagement of the screw socket is accomplished not only be elastic compression of the constituent material of the driving tool, as seen in Lazarra et al., but also by resilient compression or spring action of the jaws, which jaws and resilient compression are absent in Lazarra et al.  
         [0010]     Accordingly, it is one object of the invention to provide a screw grasping and driving tool which improves over the prior art.  
         [0011]     It is another object of the invention to enhance grasp of a socket by utilizing both elastic compression of the constituent material of the driving tool and also spring action.  
         [0012]     An additional object of the invention is to reduce difficulty of fabricating a screw grasping and driving tool.  
         [0013]     It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.  
         [0014]     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:  
         [0016]      FIG. 1  is a side elevational view of one embodiment of a driving tool according to the invention.  
         [0017]      FIG. 2  is an enlarged perspective detail view of the bottom of  FIG. 1 .  
         [0018]      FIG. 3  is similar to  FIG. 2 , but shows an alternative configuration of the jaws of the driving bit.  
         [0019]      FIG. 4  is an enlarged environmental side elevational view of the embodiment of  FIG. 1  engaging a screw for driving the latter.  
         [0020]      FIG. 5  is an enlarged perspective detail view of  FIG. 4 , partially broken away to reveal detail.  
         [0021]      FIG. 6  is an enlarged perspective detail view of the bottom left of  FIG. 2 .  
         [0022]      FIG. 7  is an enlarged perspective view of a dental implant which may be grasped and driven by the tool of the present invention.  
         [0023]      FIG. 8  is an enlarged perspective view of another embodiment of a dental implant which may be grasped and driven by the tool of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]      FIG. 1  of the drawings shows a driving tool  10  for grasping and rotatably driving a screw (see  FIG. 4 ) of the type having a polygonal female socket for engaging a driving tool. Driving tool  10  comprises a body  12  having an axis of rotation  14  and a driving bit  16  comprising two and only two opposed jaws  18 ,  20  fixed to and projecting from body  12 . Body  12  preferably takes the form of an elongate shaft wherein the length is coincident with axis of rotation  14 , as depicted in  FIG. 1 , although much shorter embodiments are contemplated. A gap  22  spaces apart or separates jaws  18 ,  20  from one another in the absence of external forces which would otherwise urge jaws  18 ,  20  towards each other.  
         [0025]     Gap  22  may have several sections rather than having configuration of a single straight line segment. For example, in an alternative embodiment of the invention (not shown) having three jaws, a three section gap would separate each jaw from every other jaw. This latter situation applies in particular to polygonal configurations having an odd number of sides, such as triangles and pentagons. When using a polygonal configuration having an even number of sides, such as square, rectangular, and hexagonal, it is preferred to use a gap having configuration of a straight line segment. However, it would be possible to modify this scheme, for example, to remove constituent material to decrease resistance to compression when the jaws are being inserted into a socket.  
         [0026]     The gap may intersect the outer periphery of the jaws at a straight face or facet, as illustrated herein, at an intersection of straight faces or facets (this construction is not shown), or in any combination of these.  
         [0027]     As clearly seen in  FIG. 2 , jaws  18 ,  20  collectively have a drivingly effective generally rectangular outer cross sectional configuration, where the cross sectional configuration is taken on a plane (such as for example plane  24  shown in  FIG. 1 ) oriented perpendicularly to rotational axis  14 . Referring also to  FIG. 4 , wherein jaws  18 ,  20  of driving tool  10  have entered and engaged a socket  2  of a screw  4 , it will be appreciated that the drivingly effective outer peripheral cross sectional configuration cooperates closely with socket  2 , thereby enabling driving screw  4  by rotation. It will be appreciated that the same cross sectional configuration occurs at different points along the length of jaws  18 ,  20 , although to progressively increasing dimensions from the end of jaws  18 ,  20  to body  12 .  
         [0028]     Although the present invention may have more than two jaws  18 ,  20  (or  118  and  120  as seen in  FIG. 3 ), it is possible to increase the number of jaws if desired. As complexity of manufacturing increases especially in miniaturized applications, it is preferred to limit the number of jaws to two. Therefore, explanation of the invention will proceed with reference to two jaws, it being understood that this may be varied.  
         [0029]     As previously mentioned, the outer peripheral cross sectional configuration of jaws  18 ,  20  is that of a rectangle. In the embodiment of  FIG. 2 , this configuration is rectangular, and more specifically square in this embodiment. In an alternative embodiment shown in  
         [0030]      FIG. 3 , this configuration is hexagonal. In  FIGS. 2 and 3 , the respective configurations are shown at the distal or relatively small ends of the respective jaws. The embodiment of  FIG. 3  is similar to that of  FIG. 2  except for the cross sectional configuration of the driving bit. The hexagonal tool is useful for both six- and twelve-pointed sockets (neither shown). In the field of dentistry, twelve pointed sockets are used to provide finer angular positioning of abutments and other components on an osseointegrated implant (not shown).  
         [0031]     Jaws  18 ,  20  engage the walls of socket  2  by friction. Cooperation with socket  2  and frictional grip of socket  2  are enhanced by resilient spring action of jaws  18 ,  20 . Jaws  18 ,  20 , and preferably all of driving tool  10 , are fabricated by a material displaying spring characteristics causing jaws  18 ,  20  to yieldingly and resiliently resist being urged together. Titanium, stainless steel, other steels, synthetic elastomers, and other materials would be suitable for imparting sufficient spring characteristics.  
         [0032]     Each jaw  18  or  20  has a respective proximal end  26  or  28  proximate body  12 , and a respective distal end  30  or  32  located away from body  12 . Each jaw  18  or  20  is tapered such that it is relatively wide at its proximal end  26  or  28 , and relatively narrow at its distal end  30  or  32 . Taper of jaws  18 ,  20  is preferably linear and continuous along the entire extent or length of one or preferably both jaws  18 ,  20 . As seen in the enlarged detail of  FIG. 5 , this taper causes external engagement surfaces  34 ,  36  of jaws  18 ,  20  each to establish and maintain a line of contact with an edge of socket  2  when driving tool  10  is inserted into socket  2 . External engagement surfaces  34 ,  36  is that surface of its respective jaw  18  or  20  which faces away from axis of rotation  14 . Each jaw  18  or  20  has one and only one external engagement surface  34  or  36 . In  FIG. 5 , edges  38 ,  40  are coincident with the lines of contact made by jaws  18 ,  20 . Each jaw  18  or  20  of the embodiment of  FIG. 2  and each jaw  118  or  120  of tool  110  of  FIG. 3  is configured and dimensioned substantially as a mirror image or alternatively stated, similarly to every other jaw ( 18  or  20 , or  118  or  120 ) of its respective tool  10  or  110 .  
         [0033]     As best shown in  FIG. 4 , it will further be seen that each jaw  18  or  20  comprises one and only one single faceted interior surface  42  or  44  facing axis of rotation  14 . As used herein, “single faceted” need not imply that the subject surface be purely planar, but rather that it be devoid of sharp edges or creases such as edge  46  (see  FIG. 2 ) or edge  148  (see  FIG. 3 ). Interior surfaces  42 ,  44  are parallel to one another when in the uncompressed state. Moreover, interior surfaces  42 ,  44  each face one another. As each jaw  18  or  22  is rectangular in cross section, it follows that for each jaw  18  or  20 , its respective external engagement surface  34  or  36  is separated or spaced apart from a corresponding single faceted interior surface by first and second lateral surfaces (not identified by reference numerals).  
         [0034]     Of course, the same holds true for the embodiment of  FIG. 3 . In the embodiment of  FIG. 4 , as jaws  18 ,  20  are progressively inserted into socket  2 , they are compressed together so that they come to touch one another at their respective distal ends  30 ,  32 . However, it is not necessary to compress jaws  18 ,  20  to the point that distal ends  30 ,  32  touch one another for engagement of screw  4  to succeed.  
         [0035]     As shown in  FIG. 6 , jaw  18  has thickness  50  defined between interior surface  44  and external engagement surface  34 . Width of jaw  18  is defined along the extent of interior surface  42 , and is indicated at  52 . It will be seen that width  52  is greater in magnitude than is thickness  50 . This same relationship holds true for jaw  20  and also for jaws  118  and  120  in the embodiment of  FIG. 3 , where thickness is indicated as  150  and width as  152  for jaw  120  (the same applying to jaw  118 ).  
         [0036]     Referring again to  FIG. 1 , body  12  of driving tool  10  is seen to have a grasping handle  34  of diameter greater than that of body  12 . Handle  34  of body  12  bears an outer surface which is textured to improve grip by hand. Texturing may take the form of ridges or reeding  36 , by roughening of the surface (not shown), or in any other suitable way. In an alternative embodiment of the invention (not shown), the outer surface being treated to improve grip may be of body  12  rather than being that of enlarged head  34 . The same texturing used with handle  34  may be applied to body  12 .  
         [0037]     In the embodiment of  FIG. 1 , which is the currently preferred embodiment, body  12  comprises an elongate shaft having length coincident with axis of rotation  14 . In the preferred embodiment, jaws  18 ,  20  project from body  12  parallel to and coaxially with axis of rotation  14 . However, this orientation is not absolutely necessary. Rather, some offset is possible, so that in an alternative embodiment (not shown), the jaws may depart from axial alignment with the shaft or body of the tool.  
         [0038]      FIG. 7  illustrates a dental implant  100  having an internal connector which takes the form of a polygonal socket  102 . Dental implants differ from most screw devices in having internal threads  104  formed in the walls of socket  102  and preferably also external threads  106 .  FIG. 8  shows a dental implant  200  also having a polygonal socket  202  and threads  204 , but having a tapered shaft  208 , in contrast to the generally cylindrical shaft  108  of the embodiment of  FIG. 7 . Dental implants also are devoid of enlarged heads which are typical of tool driven screws used for general purpose fastening, where enlarged heads have greater diameter than shafts  108 ,  208 .  
         [0039]     A significant advantage of driving a dental implant with the novel tool is that whereas unthreading a screw which is conventionally used to drive the implant may actually unthread the implant from bone tissue, pulling the novel tool from the implant does not counterrotate the implant, thereby avoiding potential unthreading.  
         [0040]     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.