Abstract:
A tool for removing debris from sockets containing screws of electrical conductors of medical pacemakers, to allow engagement of screw heads for unthreading. The tool includes a body, with a screw driving blade projecting from one end and a cutting blade of diameter similar to that of the screw driving blade projecting from an opposed end. Optionally, the body encloses torque limiting components limiting torque applied to the screw driving blade. The screw driving blade may be polygonal. The cutting blade may be a fluted drill bit. Where the torque limiting components are not provided, the body may bear external splines, with the screw driving blade and cutting blade being monolithic with the body.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/889,822, filed Oct. 11, 2013, which is hereby explicitly incorporated herein by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates to drive tools, and more particularly, to a drive tool for providing operable access to and removing screws from, for example, medical pacemakers. 
       BACKGROUND 
       [0003]    Electrical contacts in medical pacemakers must from time to time be removed to permit servicing or replacement of the medical pacemakers. These electrical contacts, their conductors, or conductive terminals, are held in place by screws which must be loosened to disconnect the contacts. The screws occupy sockets into which a screwdriver must reach. However, in the body environment, the screws may become covered by body tissue debris. This matter may interfere with ability of screwdrivers to successfully engage and drive the screws. For example, the tip of the screwdriver may become stripped as a cardiologist attempts to remove these screws if the socket is clogged by tissue debris. 
       SUMMARY 
       [0004]    The inventive tool addresses the above stated situation by providing a tool incorporating both a screw driver element and also an auger type blade for removing tissue debris which obstructs access to the screw head. Optionally, the tool may further incorporate a torque limiting feature which prevents overtightening of the screw(s). 
         [0005]    To these ends, the novel tool includes a body, a screw driving blade projecting from one end of the body, and an auger type cutting blade projecting from an opposed end of the body. The body contains within torque limiting components, where provided, acting on the screw driving blade. 
         [0006]    It is an object 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. 
         [0007]    These and other objects will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    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: 
           [0009]      FIG. 1  is an exploded perspective view of a tool for gaining access to and driving screws for pacemakers, according to at least one aspect of the disclosure; 
           [0010]      FIG. 2  is a side view of the tool of  FIG. 1 , showing the tool assembled, and further showing caps exploded from the tool; and 
           [0011]      FIG. 3  is a side view, partially in cross section, of a tool for gaining access to and driving screws for pacemakers, according to at least one further aspect of the disclosure. 
           [0012]      FIG. 4  is an enlarged environmental cross sectional detail view of a cutting bit of the tool of  FIG. 1 , shown entering a screw socket containing a screw. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring first to  FIGS. 1 and 2 , according to at least one aspect of the invention, there is shown a tool  100  for gaining access to and driving screws for pacemakers (not shown). The tool  100  comprises a body  102  including an outer enclosure  104 , a proximal end  106 , a distal end  108 , and an axis of rotation  110 . The tool  100  also comprises a screw driving blade  112  projecting from body  102  along axis of rotation  110 , from proximal end  106 , and a cutting bit  114  supported by body  102  along axis of rotation  110 , cutting bit  114  projecting from body  102  from distal end  108 . Cutting bit  114  is fluted and has an exposed cutting tip  116  projecting from body  102 . Screw driving blade  112 , cutting bit  114 , and orientation of these on body  102  along axis of rotation  110  facilitate access to and removal of screws for pacemakers. 
         [0014]    Body  102  is a structural member holding functional components of tool  100  in operable positions aligned along axis of rotation  110 . Body  102  encloses and protects optional torque limiting components, which will be further described hereinafter. 
         [0015]    Optionally, cutting bit  114  is fixed to body  102 . This may be accomplished by overmolding body  102  with respect to cutting blade  114 , by bonding cutting blade  114  to body  102 , by crimping cutting blade  114  to body  102 , or in any other suitable way. 
         [0016]    Referring also to  FIG. 4 , where a socket  10  contains a screw  12  fastening an electrical conductor or terminal  14  of the latter in place within a medical pacemaker (not shown in its entirety), debris  16  from body tissues may come to clog socket  10 . Cutting bit  114  bores through debris  16 , including most of the debris  16  occupying a drive hole  18  of screw  12 , and evacuates debris  16  from screw  12  and socket  10 . 
         [0017]    In at least one implementation of the disclosure, cutting bit  114  has a biologically inert external layer. Cutting bit  114  having a biologically inert external layer avoids metallic or other chemical contamination of the body. In a further implementation of the disclosure, the biologically inert external layer may comprise titanium. Titanium is a durable, biologically inert material highly suitable for cutting bit  114 . A biologically inert layer comprising titanium may be achieved by coating cutting bit  114  with titanium or a titanium compound, such as titanium nitride. It would also be possible to fabricate all or much of cutting bit  114  from titanium or an alloy thereof. 
         [0018]    In at least one implementation of the disclosure, cutting tip  116  is blunt ended. This configuration enables cutting tip  116  to enter drive hole  18  and remove most of the debris  16  where the bottom of drive hole  18  has a flat floor. 
         [0019]    In at least one implementation of the disclosure, screw driving blade  112  is polygonal in cross section, has a cross sectional diameter  122  between two opposed sides  120  of screw driving blade  112 . Cutting bit  114  has a diameter  124  equal to a dimension between two opposed sides  120  of screw driving blade  112 . The dimension between two opposed sides  120  of screw driving blade  112  is seen as cross sectional diameter  122  in  FIG. 1 . This relationship causes cutting bit  114  to remove most of the debris  16  from drive hole  18  of screw  12 , thereby enabling screw driving blade  112  to engage drive hole  18  without rounding corners or apices of screw driving blade  112 . 
         [0020]    In at least one implementation of the disclosure, cutting bit  114  has two flutes  126 . Two flutes  126  increase and may maximize debris evacuation capacity of cutting bit  114  as the latter is rotated to remove debris  16 . 
         [0021]    In at least one implementation of the disclosure, tool  100  further comprises a first cap  130  configured to cover cutting bit  114  and retainably engage body  102 . First cap  130  slips over and engages by friction a surface  132  of body  102 . First cap  130  protects people and objects from damage due to contact with exposed cutting edges of cutting bit  114 , and protects cutting bit  114  from damage due to contact with an external object (not shown). 
         [0022]    In at least one implementation of the disclosure, tool  100  further comprises a second cap  134  configured to cover screw driving blade  112  and retainably engage body  102 . Second cap  134  slips over and engages by friction a surface  136  of body  102 . Second cap  134  protects people and objects from damage due to contact with screw driving blade  112 . 
         [0023]    First and second caps  130 ,  134  may be fabricated from a slightly flexible material such as a synthetic polymer or natural rubber. First and second caps  130 ,  134  may comprise internal ribs  138  ( FIG. 1 ) which engage corresponding ribs  140  of body  102  to promote secure retention of first and second caps  130 ,  134 . 
         [0024]    Referring specifically to  FIG. 1 , in at least one implementation of the disclosure, tool  100  comprises a torque limiting feature operable to limit torque imparted to screw driving blade  112  when rotating body  102 . The torque limiting components act on screw driving blade  112  to torque a screw such as screw  12  of  FIG. 4  to a specified torque value, without exceeding that torque value. Hence tool  100  can be expeditiously used without obliging the user to monitor or carefully limit torques imposed on the item driven by tool  100 . 
         [0025]    Torque limiting components for screw driving blade  112  include a first member  150  having downwardly projecting teeth  152  (downwardly projecting as seen in  FIG. 1 ), each tooth  152  including a ramp arranged at a small angle to a hypothetical plane perpendicular to rotational axis  110 . The small angle may be for example five to thirty degrees from the hypothetical plane. 
         [0026]    First member  150  has an opposed second member  154  bearing teeth  156 . Second member  154  is fixed to body  102 . An aperture  160  in second member  154  is configured to cooperate closely yet slidably with the outer surface of shaft  162  of screw driving blade  112 . For example, both the outer surface of shaft  162  and the inner surface of aperture  160  may be hexagonal. 
         [0027]    Although not visible in the view of  FIG. 1 , teeth  156  are arranged in a complementary manner, interfitting with teeth  152  but being opposite in pitch. When first and second members  150 ,  154  are mutually rotated about rotational axis  110  in one direction, initially, second member  154  rotates first member  150 . As resistance from an object driven by  112  increases, first and second members  150 ,  154  will mutually repel or displace one another as the opposed ramps of teeth  152 ,  156  slide across one another. Rotation of first member  150  continues until first and second members  150 ,  154  are mutually displaced to the point that the apices of teeth  152 ,  156  slide past each other. A spring  158  adjustably varies resistance to mutual displacement of first and second members  150 ,  154 , thereby varying the maximum torque which can be transmitted to second member  154  from first member  150 . 
         [0028]    A threaded plug  164  is adjusted by a wrench (not shown) which cooperates with castellation  166  to adjust resistance of spring  158 . Threads  168  of threaded plug  164  engage threads  170  (concealed from view in  FIG. 1 ) of body  102 . The maximum torque value is calibrated by determining position of threaded plug  164  along body  102  prior to fixing threaded plug  164  to body  102 . Threaded plug  164  may engage body  102  by glue, by distortion to threads  168  or  170 , or in any other suitable way. 
         [0029]    Referring now to  FIG. 3 , there is shown a tool  100  for gaining access to and driving screws for pacemakers. Tool  100  comprises a body  102  including an outer enclosure  104 , a proximal end  106 , a distal end  108 , and an axis of rotation  110 . The tool  100  also comprises a screw driving blade  112  projecting from body  102  along axis of rotation  110 , from proximal end  106 , and a cutting bit  114  supported by body  102  along axis of rotation  110 , cutting bit  114  projecting from body  102  from distal end  108 . In the implementation of  FIG. 3 , screw driving blade  112  is fixed to body  102 . Body  102  is solid, screw driving blade  112  and cutting bit  114  embedded within body  102 . Body  102  includes external splines  128 . External splines  128  not only facilitate secure manual grasp of body  102 , but also enable tool  100  to cooperate with a torque wrench (not shown) having a socket cooperating with body  102 . This enables an inexpensive version of tool  100  to be realized. 
         [0030]    Tool  100  has been described for use in the environment of medical pacemakers only for convenience of understanding in terms of applying tool  100  to an environment having recognizable characteristics. It should be realized that tool  100  is not limited to this environment, and may be utilized in any environment where it is desired to remove debris or other material, such as sealing materials, to gain access to and drive the head of a fastener or other object. 
         [0031]    Further, as a non-limiting example, the cutting bit  114  may be a separate tool onto itself. The cutting bit may be detached from the torque tool  100  and attached to an accompanied handle supporting the cutting bit. As such, the cutting bit may be used as a separate tool to clean out the screw socket. 
         [0032]    Unless otherwise indicated, the terms “first”, “second”, etc., are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the times to which these terms refer. Moreover, reference to, e.g., a “second” item does not either require or preclude the existence of, e.g., a “first” or lower-numbered item, and/or, e.g., a “third” or higher-numbered item. 
         [0033]    It should be understood that the various examples of the apparatus(es) disclosed herein may include any of the components, features, and functionalities of any of the other examples of the apparatus(es) disclosed herein in any feasible combination, and all of such possibilities are intended to be within the spirit and scope of the present disclosure. Many modifications of examples set forth herein will come to mind to one skilled in the art to which the present disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. 
         [0034]    Therefore, it is to be understood that the present disclosure is not to be limited to the specific examples presented and that modifications and other examples are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated drawings describe examples of the present disclosure in the context of certain illustrative combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative implementations without departing from the scope of the appended claims.