Medical reamers and methods of forming the same

Abstract

A cutting tool is provided with a cutting surface on a first side of the cutting tool and an attachment member on a second side of the cutting tool. The cutting surface can have cutting edges with characteristics that vary along the cutting tool. Novel methods of manufacturing such cutting tools are also provided.

We claim: 
     
         1 . A cutting tool comprising:
 a cutting surface on a first side of the cutting tool, the cutting surface comprising a plurality of cutting edges; and   an attachment member on a second side of the cutting tool, the attachment member being configured to be coupled to a powered driving member;   wherein the cutting tool comprises an axis of rotation and the cutting surface defines a plurality of latitude lines, the plurality of cutting edges are oriented at varying orientation angles relative to the latitude lines.   
     
     
         2 . The cutting tool of  claim 1 , wherein the plurality of cutting edges are provided in at least three different zones and respective cutting edges in the different zones have different characteristics. 
     
     
         3 . The cutting tool of  claim 2 , wherein the different zones comprise a polar zone, a transition zone, and an equatorial zone. 
     
     
         4 . The cutting tool of  claim 3 , wherein respective cutting edges define a cutting angle between the cutting edge and a perpendicular to the first side of the cutting tool, and the cutting angle between cutting edges in the polar zone are larger than those defined by cutting edges in the transition zone, and the cutting angle between cutting edges in the transition zone are larger than those defined by cutting edges in the equatorial zone. 
     
     
         5 . The cutting tool of  claim 3 , wherein the orientation angles vary depending on whether the respective cutting edges are in the polar zone, the transition zone, or the equatorial zone, and
 the orientation angle of respective cutting edges in the equatorial zone is greater than the orientation angle of respective cutting edges in the transition zone, and the orientation angle of respective cutting edges in the transition zone is greater than the orientation angle of respective cutting edges in the polar zone.   
     
     
         6 . The cutting tool of  claim 1 , wherein the thickness of the side wall is less than 0.040 inches. 
     
     
         7 . The cutting tool of  claim 1 , wherein the thickness of the side wall is between 0.022 inches and 0.40 inches. 
     
     
         8 . The cutting tool of  claim 1 , further comprising openings adjacent respective cutting edges, the respective openings defining a funnel angle that is between 20 and 40 degrees. 
     
     
         9 . The cutting tool of  claim 8 , wherein the funnel angle is between 25 and 35 degrees. 
     
     
         10 . The cutting tool of  claim 1 , wherein the cutting tool comprises a hollow spherical reamer, a hollow tapered reamer, or a hollow cylindrical reamer. 
     
     
         11 . The cutting tool of  claim 1 , wherein the cutting surface is a panel and the cutting tool comprises a plurality of separate panels. 
     
     
         12 . The cutting tool of  claim 11 , further comprising a center support and a base, the plurality of separate panels being coupled to the center support and the base. 
     
     
         13 . A method of forming a cutting tool comprising:
 forming a plurality of panels from one or more flat sheets of metal, the plurality of panels being formed with a plurality of cutting edges and a plurality of openings adjacent respective cutting edges; and   coupling the plurality of panels to a frame member to form the cutting tool,   wherein, when coupled to the frame member, the plurality of panels define a plurality of latitude lines about the axis of rotation of the cutting tool and the plurality of formed cutting edges have orientation angles relative to the latitude lines that vary.   
     
     
         14 . The method of  claim 13 , wherein respective panels have cutting edges with orientation angles that vary along the respective panel. 
     
     
         15 . The method of  claim 13 , wherein the act of forming a plurality of panels comprises stamping the one or more flat sheets of metal to form a plurality of cavities and punching holes at or adjacent to the plurality of cavity to provide bone-chip-receiving openings. 
     
     
         16 . The method of  claim 15 , wherein the act of forming the plurality of cavities comprises forming a plurality of “V”-shaped cavities. 
     
     
         17 . The method of  claim 16 , wherein the act of forming the plurality of panels further comprises stamping the one or more panels to create a desired height of the cutting edges and to provide a desired curvature of the one or more panels. 
     
     
         18 . The method of  claim 15 , wherein the act of coupling the plurality of panels to the frame member comprises:
 forming a frame member that comprises a center support, a base, and a form dome; and   securing the plurality of panels to the center support, the base, and the form dome.   
     
     
         19 . The method of  claim 18 , wherein the act of securing the plurality of panels to the center support, the base, and the form dome comprises laser welding. 
     
     
         20 . The method of  claim 15 , wherein the act of coupling the plurality of panels to the frame member comprises:
 placing the plurality of panels into an injection molding tool; and   injection molding the frame member around the plurality of panels to create the frame member.   
     
     
         21 . The method of  claim 15 , wherein the act of forming a plurality of panels from one or more flat sheets of metal comprises forming the plurality of cutting edges with different zones that have cutting edges with different characteristics, the different zones comprising a polar zone, a transition zone, and an equatorial zone. 
     
     
         22 . The method of  claim 21 , wherein respective cutting edges define a cutting angle between the cutting edge and a perpendicular to a first side of the cutting tool, and the cutting angle between cutting edges in the polar zone are larger than those defined by cutting edges in the transition zone, and the cutting angle between cutting edges in the transition zone are larger than those defined by cutting edges in the equatorial zone. 
     
     
         23 . The method of  claim 15 , wherein the one or more flat sheets of metal have a thickness less than 0.040 inches. 
     
     
         24 . The method of  claim 15 , wherein the act of punching holes at or adjacent to the plurality of cavity comprises forming bone-chip-receiving openings with a funnel angle that is between 20 and 40 degrees. 
     
     
         25 . The method of  claim 13 , wherein the cutting tool comprises a hollow spherical reamer, a hollow tapered reamer, or a hollow cylindrical reamer. 
     
     
         26 . The method of  claim 13 , further comprising:
 determining an effective functional life of the cutting tool.   
     
     
         27 . A cutting tool comprising:
 a cutting surface on a first side of the cutting tool, the cutting surface comprising a plurality of cutting edges; and   an attachment member on a second side of the cutting tool, the attachment member being configured to be coupled to a powered driving member;   wherein the plurality of cutting edges are in three different zones and respective cutting edges in the different zones have different characteristics.