Coupling portion for rotary surgical cutting systems

Abstract

Aspects of the disclosure relate to surgical cutting systems having a surgical tool and a powered hand piece. The surgical tool can include a cutting tool having a coupling portion for selective connection to a drive pin of the hand piece. The coupling portion defines a tang that is configured to promote self-alignment of the cutting tool and the drive pin during connection of the cutting tool and the hand piece, thus promoting ease of use.

What is claimed is: 
     
         1 . A method of assembling a surgical cutting system, the method comprising:
 providing a hand piece including a drive pin;   providing a cutting tool including a cutting head and a coupling portion coupled to the cutting head such that rotation of the coupling portion correspondingly rotates the cutting head; wherein the coupling portion can releasably connect the cutting tool to the hand piece; further wherein the coupling portion includes a tang and a distal portion interconnected by an intermediate stem portion; and   inserting the tang into the drive pin of the hand piece in a misaligned position, wherein the tang is configured such that during a step of continued insertion of the tang, the tang self-aligns with the drive pin until the tang is in a fully seated position with the drive pin.   
     
     
         2 . The method of  claim 1 , wherein the intermediate stem portion defines a central axis; further wherein the tang includes:
 an extension portion coaxially aligned with the central axis;
 a first interface surface defining a first plane that is parallel with the central axis; the first interface surface terminating at a first end surface oriented perpendicular to the first plane; 
 a first ramp portion extending distally from the first end surface adjacent the extension portion at a first angle with respect to the first interface surface; 
 a second interface surface defining a second plane that is that is parallel with the central axis; the second interface surface terminating at a second end surface oriented perpendicular to the second plane; and 
 a second ramp portion extending distally from the second end surface adjacent the extension portion at a second angle. 
   
     
     
         3 . The method of  claim 2 , wherein the first angle is in a range of 5 to 85 degrees with respect to the first interface surface. 
     
     
         4 . The method of  claim 2 , wherein the second angle is in a range of 5 to 85 degrees. 
     
     
         5 . The method of  claim 2 , wherein during the step of inserting, upon contact with the drive pin and with continued insertion forces applied, the tang is urged via each ramp portion into alignment, along a guide surface of the drive pin into the fully seated position. 
     
     
         6 . The method of  claim 2 , wherein rotational movement of the tang in either a clockwise or counterclockwise direction fully seats the interface surfaces of the tang with drive surfaces of the drive pin to rotate the coupling portion. 
     
     
         7 . The method of  claim 2 , wherein an arcuate, first interface wall extends radially away from the first interface surface. 
     
     
         8 . The method of  claim 7 , wherein the first interface wall extends between the second ramp portion and a convergence point, which is a most proximal point at which the first interface wall contacts the first interface surface. 
     
     
         9 . The method of  claim 2 , wherein the extension portion terminates at a tip. 
     
     
         10 . The method of  claim 9 , wherein the tip is domed. 
     
     
         11 . The method of  claim 9 , wherein the tip defines a planar surface that is perpendicular to the central axis. 
     
     
         12 . The method of  claim 2 , wherein the first and second interface surfaces are planar. 
     
     
         13 . The method of  claim 2 , wherein the first and second ramp portions are helical with respect to the extension portion. 
     
     
         14 . The method of  claim 2 , wherein the extension portion is cylindrical. 
     
     
         15 . The method of  claim 2 , wherein the first interface surface is identically configured with respect to the second interface surface. 
     
     
         16 . The method of  claim 2 , wherein the coupling portion has first and second sides, each side including one of the first or second interface surfaces; further wherein the first side is a mirror image of the second side. 
     
     
         17 . The method of  claim 2 , wherein the first ramp portion defines a straight outer edge. 
     
     
         18 . The method of  claim 2 , wherein the first interface surface has a maximum width in the range of 0.25 mm to 2.0 mm. 
     
     
         19 . The method of  claim 2 , wherein the second end surface is approximately 180 degrees from the first end surface. 
     
     
         20 . The method of  claim 2 , wherein the extension portion terminates adjacent the first end surface.