for the purpose of promoting an understanding of the present invention , references are made in the text to exemplary embodiments of an internal adapter for orthopedic tools , only some of which are described herein . it should be understood that no limitations on the scope of the invention are intended by describing these exemplary embodiments . one of ordinary skill in the art will readily appreciate that alternate but functionally equivalent structures and materials may be used . the inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art . specific elements disclosed herein are not to be interpreted as limiting , but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention . it should be understood that the drawings are not necessarily to scale ; instead , emphasis has been placed upon illustrating the principles of the invention . in addition , in the embodiments depicted herein , like reference numerals in the various drawings refer to identical or near identical structural elements . fig1 is an exploded view of an exemplary embodiment of self - locking internal adapter 100 . internal adapter has collar assembly 10 , house 20 , retaining ring 30 , spring 40 , shaft driver assembly 50 , and securing balls 60 a , 60 b , 60 c , 60 d . when assembled , internal adapter 100 is configured to be secured in handle 70 . as illustrated in fig1 , collar assembly 10 , house 20 , retaining ring 30 , spring 40 and shaft driver assembly 50 are shown as separately manufactured components . in further exemplary embodiments , two or more of collar assembly 10 , house 20 , retaining ring 30 , spring 40 and shaft driver assembly 50 integrally manufactured or machined . in still further exemplary embodiments , one or more of collar assembly 10 , house 20 , retaining ring 30 , spring 40 and shaft driver assembly 50 may be integrally manufactured with handle 70 . in the exemplary embodiment shown , handle 70 is a countered driver handle . in further exemplary embodiments , internal adapter 100 may be used with a torque driver , ratcheting driver , or other driver known in the art . as illustrated in fig1 , retaining ring 30 has gap 31 . in further exemplary embodiments , retaining ring 30 may be a complete ring without gaps . fig2 a and 2 b illustrate an exemplary embodiment of collar assembly 10 . collar assembly 10 contains external collar base 11 and tubular sliding portion 14 , with tool receiving channel 16 extending the length of collar assembly 10 . in the exemplary embodiment shown , tubular sliding portion 14 contains securing ball apertures 15 a , 15 b 15 c , 15 d . securing ball apertures 15 a , 15 b , 15 c , 15 d are equidistant and symmetrically arranged around tubular sliding portion 14 . in further exemplary embodiments , tubular sliding portion 14 may contain additional securing ball apertures . while equidistant and symmetrically arranged securing ball apertures provides for greater securing and stability , in further exemplary embodiments , securing ball apertures may be asymmetrically arranged and positioned at varying distances around tubular sliding portion 14 . securing ball apertures 15 a , 15 b , 15 c , 15 d contain a contoured inner surface which creates a diameter smaller than the diameter of securing balls 60 a , 60 b , 60 c , 60 d ( not shown ) at the innermost edge of securing ball apertures 15 a , 15 b , 15 c , 15 d . securing balls 60 a , 60 b , 60 c , 60 d ( not shown ) are therefore freely rotatable within securing ball apertures 15 a , 15 b , 15 c , 15 d but may not pass through securing ball apertures 15 a , 15 b , 15 c , 15 d . in further exemplary embodiments , securing ball apertures 15 a , 15 b , 15 c , 15 d may contain a lip , rim , ridge or other structure which narrows the diameter of the innermost edge of securing ball apertures 15 a , 15 b , 15 c , 15 d to prevent securing balls 60 a , 60 b , 60 c , 60 d ( not shown ) from passing through . fig2 a and 2 b also show tool receiving channel 16 extending the length of collar assembly 10 . in the exemplary embodiment illustrated , tool receiving channel 16 is round tubular with a smooth surface and consistent internal diameter . in further exemplary embodiments , tool receiving channel may contain projections or grooves or may have an inconsistent internal diameter to accommodate a specifically manufactured tool . the rear end of tubular sliding portion 14 contains protuberance 17 and groove 18 , both of which span the external circumference of tubular sliding portion 14 . fig3 is an exemplary embodiment of house 20 . as shown in fig3 , house 20 contains external house base 21 with threaded handle - engaging stem 22 . interior collar channel 23 contains retaining ring securing protuberance 24 and extends the length of house 20 . fig4 a , 4 b and 4 c illustrate an exemplary embodiment of shaft driver assembly 50 . shaft driver assembly 50 has front threaded portion 51 with tapered rear portion 52 . front threaded portion 51 has apertures 53 a , 53 b . tool guiding channel 54 extends the length of shaft driver 50 . as illustrated in fig4 a , 4 b and 4 c , tool guiding channel 54 is primarily round tubular with a smooth internal surface at the front of shaft driver 50 . the diameter of tool guiding channel 54 decreases at chamfer 55 , creating interior lip 57 . chamfer 55 transitions tool guiding channel 54 to a narrower diameter which includes guiding chamfers 56 . in the exemplary embodiments shown , tool guiding channel 54 contains eight double square guiding chamfers 56 . in further exemplary embodiments , guiding chamfers may be hexagonal or other configuration , and tool guiding channel 54 may contain more or fewer guiding chamfers 56 to correspond to a guiding chamfer configuration . as shown in fig4 a and 4 c , guiding chamfers 56 do not start at the edge of chamfer 55 and have leading transition chamfer 58 . as will be illustrated in fig8 a , 8 b and 8 c , the proportional distance of leading transition chamfer 58 of guiding chamfers 56 from chamfer 55 is a critical dimension . fig5 is a cross - sectional view of an exemplary embodiment of an assembled self - locking internal adapter 100 . as illustrated in fig5 , handle 70 has internal handle cavity 71 with front threaded portion 72 . the threads of front threaded portion 72 correspond to the threads of threaded handle - engaging stem 22 and front threaded portion 51 to secure self - locking internal adapter 100 within internal handle cavity 71 . in further exemplary embodiments , self - locking internal adapter 100 may be configured to secure to internal handle cavity 71 through any other means known in the art , including , but not limited to , adhesives , pins , locking mechanisms , brackets , screws , contours , friction - fit components , and combination of these structures and devices . in still further exemplary embodiments , self - locking internal adapter 100 may be an integral component of handle 70 . in the exemplary embodiment shown , handle 70 is a standard drive handle . however , in further exemplary embodiments , handle 70 may be any handle known in the art to receive orthopedic tools , including , but not limited to , torque - limiting handles and ratcheting handles . as illustrated in fig5 , external house base 21 and external collar base 11 are the only components of self - locking internal adapter 100 which project outside of handle 70 . in some exemplary embodiments , only external collar base 11 may project outside of handle 70 . collar assembly 10 is showed slidingly engaged with house 20 , with tubular sliding portion 14 of collar assembly 10 inside interior collar channel 23 ( not shown ) of house 20 . in the exemplary embodiment shown in fig5 , internal handle cavity 71 also contains tapered rear portion 75 which corresponds to tapered rear portion 52 of shaft driver assembly 50 . the tapered engagement of shaft driver assembly 50 with handle 70 centers internal adapter 100 and therefore a tool . fig6 is an exemplary embodiment of the self - locking mechanism of internal adapter 100 . as illustrated in fig6 , securing balls 60 are contained within securing ball apertures 15 , with interior collar channel 23 of house 20 creating a cover over securing ball apertures 15 to prevent securing balls 60 from disengaging securing ball apertures 15 . contoured inner surface 19 of securing ball apertures 15 prevents securing balls 60 from slipping through securing ball apertures 15 and entering tool receiving channel 16 . as shown in the exemplary embodiment illustrated in fig6 , the inner surface of interior collar channel 23 has tapered portion 25 which corresponds to securing ball apertures 15 . as spring 40 exerts outward force on collar assembly 10 , securing balls 60 in securing ball apertures 15 are forced to align with the outer - most , or narrowest , part of tapered portion 25 . retaining ring 30 , in groove 18 , is also pushed against stop - ridge 27 of house 20 , which prevents collar assembly 10 from being forced too far outward by spring 40 . as a tool would be pushed into tool receiving channel 16 , securing balls 60 freely rotate within securing ball apertures 15 , allowing the tool shaft to proceed through tool receiving channel 16 and into tool guiding channel 54 ( not shown ). when a tool shaft is pushed into tool receiving channel 16 , securing balls 60 are forced slightly towards the inner - most , or wider , part of tapered portion 25 . if the tool is pulled out from tool receiving channel 16 , securing balls 60 are forced toward the outer - most , or narrowest , part of tapered portion 25 , so that securing balls 60 are no longer able to freely rotate . the tool shaft is therefore locked within tool receiving channel 16 . to remove a tool from internal adapter 100 , external collar base 11 is pressed inward toward handle 70 . spring 40 is compressed , and collar assembly 10 slides inward within interior collar channel 23 . securing ball apertures 15 align with the inner - most , or widest , part of tapered portion 25 , which increases the volume of securing ball apertures 15 . securing balls 60 are then able to freely rotated within securing ball apertures 15 , allowing the tool shaft to be pulled out of tool receiving channel 16 . as illustrated in fig6 , retaining ring 30 is secured in groove 18 with spring 40 positioned between and housed within house 20 and shaft driver assembly 50 . the front portion of spring 40 rests against tubular sliding portion 14 around protuberance 17 and the rear portion of spring 40 rests against interior lip 57 of tool guiding channel 54 before transitional chamfer 55 . fig7 is an exemplary embodiment of tool shaft 82 for tool 80 which may be used with internal adapter 100 . at one end of tool shaft 82 is handle - engaging portion 87 . the opposite end of tool shaft 82 may contain any tool known in the art . as illustrated in fig7 , groove 81 transitions tool shaft 82 to handle - engaging portion 87 , which is squared with flat surfaces 85 a , 85 b ( 85 c , 85 d not shown ). in further exemplary embodiments , handle - engaging portion may be hexagonal or any other configuration known in the art . flat surfaces 85 a , 85 b ( 85 c , 85 d not shown ) each have a corresponding chamfer 83 a ( 83 b , 83 c , 83 d not shown ) and are separated by rounded transitions 84 a , 84 b ( 84 c , 84 d not shown ), each also have a corresponding chamfer 86 a , 86 b ( 86 c , 86 d not shown ). the distance from the center of groove 81 and edge of chamfer 86 a is labeled as a . fig8 a , 8 b and 8 c illustrate an exemplary embodiment of internal adapter 100 engaging tool 80 . as illustrated in fig8 a , tool 80 is partially inserted into internal adapter 100 . chamfers 86 engage securing balls 60 and force them into the larger area created by tapered portion 25 . securing balls 60 are able to freely rotate in securing ball apertures 15 ( not shown ) and tool shaft 82 is able to pass through tool receiving channel 16 . the distance from the center of securing balls 60 to leading transition chamfer 58 of guiding chamfers 56 is labeled as b . in the exemplary embodiment shown , distance a is equal to distance b . it is critical that distances a and b are equal to provide quick and secure locking of tool shaft 82 in internal adapter 100 . in fig8 b , tool shaft 82 is further in tool receiving channel 16 , with groove 81 aligned with securing balls 60 and chamfers 86 aligned with leading transition chamfer 58 ( not shown ) of guiding chamfers 56 . in order to fully secure tool shaft 82 in internal adapter 100 , flat surfaces 85 must properly align with guiding chamfers 56 . securing balls 60 do not engage tool shaft 82 in this position , allowing tool shaft 82 to freely rotate within tool receiving channel 16 and be properly oriented to engage guiding chamfers 56 . fig8 c illustrates tool 80 secured within internal adapter 100 . tool shaft 82 is aligned so that handle - engaging portion 87 is aligned with guiding chamfers 56 to prevent rotational movement of tool 80 in handle 70 ( not shown ). securing balls 60 are positioned along the portion of tapered surface 25 creating a smaller volume for securing ball apertures 15 and engage tool shaft 82 and prevent movement of tool 80 out of handle 70 . if tool 80 is pulled outward from handle 70 , securing balls 60 are unable to rotate within securing ball apertures 15 and prevent movement of tool shaft 82 . to release tool 80 , collar assembly 10 is pushed inward toward handle 70 to compress spring 40 . securing balls 60 are aligned with the portion of tapered surface 25 creating a larger volume for securing ball apertures 15 . securing balls 60 are therefore able to freely rotate in securing ball apertures 15 , allowing tool shaft 82 to be removed from internal adapter 100 . in the exemplary embodiment shown in fig8 c , chamfers 83 corresponding with flattened surfaces 85 correspond to and engage leading transition chamfers 58 to stabilize tool 80 .
an internal adapter for use in handles for interchangeable orthopedic tools contains a collar assembly , house assembly , retaining ring , spring and driver assembly . a plurality of securing ball mechanisms releasably secure an orthopedic tool in the adapter , while a configuration of chamfered surfaces centrally stabilize the tool . a plurality of guiding chamfers located in a shaft driver assembly rotationally secures the orthopedic tool .