Surgical handpiece with a drive spindle having a distal bore to which locking elements are mounted and an adjacent proximal bore defined by faces shaped to transfer torque to the attached cutting accessory

Abstract

A surgical handpiece with a rotating spindle for receiving the coupling head of a cutting accessory. The spindle has a proximal bore with faces shaped to transfer torque to the cutting accessory. A distal bore extends forward from and the proximal bore to the distal end of the spindle. The distal bore is shaped so the outer perimeter of the bore is located radially outwardly from the proximal bore. One or more openings are formed in the spindle open into the distal bore. The openings are forward of the proximal end of the distal bore. A locking member is able to move in and out of each opening so as to move in and out of the distal bore. The locking members, when seated in the distal bore releasable hold the cutting accessory seated in the distal and proximal bores to the spindle.

What is claimed is: 
     
         1 . A surgical tool comprising:
 a housing;   a motor disposed in said housing, said motor having a rotating shaft;   a spindle rotatably mounted to said housing, said spindle being connected to said motor shaft to be rotated by said motor shaft, said spindle having a distal end and being shaped to define: a distal bore that extends proximally from the distal end the spindle, the distal bore having an outer perimeter and proximal end; a proximal bore that is contiguous with the distal bore and extends proximally from the distal end of the distal bore, the proximal bore being defined by plural spindle inner faces that are located inwardly of the outer perimeter of the distal bore and that are shaped to transmit torque to the proximal end of the cutting accessory seated in the distal and proximal bores; and at least one opening into the distal bore that is located forward of the proximal end of the distal bore; and   a coupling assembly attached to said housing or said spindle for removably holding the cutting accessory in the spindle bore, said coupling assembling including at least one locking member that is positioned to move in and out of the at least one opening of into the distal bore so as move in and out of the distal bore, so that when said at least one locking member is disposed in the distal bore, said at least one locking member holds the proximal end of the cutting accessory in the distal and proximal bores of said spindle.   
     
     
         2 . The surgical tool of  claim 1 , further including a pin is statically mounted to said spindle so as to project into the distal bore of said spindle. 
     
     
         3 . The surgical tool of  claim 1 , wherein a pin is statically mounted to said spindle so as to project into the distal bore and said pin is mounted to said spindle so as to be located distal to the proximal end of the distal bore and proximal to the at least one opening formed in the distal bore. 
     
     
         4 . The surgical tool of  claim 1 , wherein said spindle is shaped so that the plurality of faces that define the proximal bore of said spindle are shaped so that the proximal bore, in cross section, is in the shape of polygon. 
     
     
         5 . The surgical tool of  claim 1 , further including a gear train that connects said rotating shaft of said motor to said spindle. 
     
     
         6 . The surgical tool of  claim 1 , further including a gear train that connects said rotating shaft of said motor to said motor and said gear train is configured to reduce the rotational speed of spindle relative to the rotation speed of said motor shaft. 
     
     
         7 . The surgical tool of  claim 1 , further including:
 a gear train assembly mounted in said housing, said gear train assembly having a plurality of drive heads that are connected to said motor shaft to rotate at different speeds upon actuation of said motor shaft; and   a clutch assembly that selectively connects a single one of said gear train drive heads to said spindle so that said spindle is rotated by the said drive head to which said spindle is connected.   
     
     
         8 . The surgical tool of  claim 1 , wherein said:
 said spindle is formed with a plurality of openings into the distal bore; and   said coupling assembly includes a plurality of locking members, each said locking member being positioned to move out of a separate one of the openings into the distal bore.   
     
     
         9 . The surgical tool of  claim 1 , wherein said coupling assembly at least one locking member is a pin. 
     
     
         10 . The surgical tool of  claim 1 , wherein: a longitudinal axis extends proximally to distally through the spindle; and said spindle is formed so that the at least one opening into the distal bore is in the form of a slot that is centered on a plane that is angled relative to the longitudinal axis of the spindle, the angle being selected so that the at least one locking member that moves in and out of the slot moves diagonally relative to the longitudinal axis of said spindle. 
     
     
         11 . The surgical tool of  claim 1 , wherein said spindle is further formed so that the distal bore has a circular cross sectional profile. 
     
     
         12 . A surgical tool comprising:
 a housing;   a motor disposed in said housing, said motor having a rotating shaft;   a spindle rotatably mounted to said housing, said spindle being connected to said motor shaft to be rotated by said motor shaft, said spindle shaped to have: a plurality of inner faces that define a proximal bore internal to the spindle, the inner faces shaped to transfer torque to a define a cutting accessory seated in the proximal bore; a distal bore that extends forward from the proximal bore to a distal end of the spindle so as to define a distal opening in the spindle for receiving the cutting accessory and, wherein, the distal bore has an outer perimeter that is located radially outwardly of the proximal bore; and at least one opening into the distal bore, the at least one opening being spaced distally away from the proximal bore;   a pin that is statically mounted to said spindle so as to extend in the distal bore, said pin being located distal to the proximal bore and proximal to the at least one opening into the distal bore; and   a coupling assembly attached to said housing or said spindle for removably holding the cutting accessory in the spindle bore, said coupling assembling including at least one locking member that is positioned to move in and out of the at least one opening of into the distal bore so as move in and out of the distal bore, so that when said at least one locking member is disposed in the distal bore, said at least one locking member holds the proximal end of the cutting accessory in the distal and proximal bores of said spindle.   
     
     
         13 . The surgical tool of  claim 12 , wherein said spindle is shaped so that the plurality of inner faces that define the proximal bore of said spindle are shaped so that the proximal section of the spindle bore, in cross section, is in the shape of a polygon. 
     
     
         14 . The surgical tool of  claim 12 , wherein said spindle is shaped so that the plurality of inner faces that define the proximal bore of said spindle are shaped so that the proximal section of the spindle bore, in cross section, is in the shape of a hexagon. 
     
     
         15 . The surgical tool of  claim 12 , further including a gear train that connects said rotating shaft of said motor to said spindle. 
     
     
         16 . The surgical tool of  claim 12 , further including a gear train that connects said rotating shaft of said motor to said motor and said gear train is configured to reduce the rotational speed of spindle relative to the rotation speed of said motor shaft. 
     
     
         17 . The surgical tool of  claim 12 , further including:
 a gear train assembly mounted in said housing, said gear train assembly having a plurality of drive heads that are connected to said motor shaft to rotate at different speeds upon actuation of said motor shaft; and   a clutch assembly that selectively connects a single one of said gear train drive heads to said spindle so that said spindle is rotated by the said drive head to which said spindle is connected.   
     
     
         18 . The surgical tool of  claim 12 , wherein said:
 said spindle is formed with a plurality of openings into the distal bore; and   said coupling assembly includes a plurality of locking members, each said locking member being positioned to move out of a separate one of the openings into the distal bore.   
     
     
         19 . The surgical tool of  claim 12 , wherein said coupling assembly at least one locking member is a pin. 
     
     
         20 . The surgical tool of  claim 12 , wherein: a longitudinal axis extends proximally to distally through the spindle; and said spindle is formed so that the at least one opening into the distal bore is in the form of a slot that is centered on a plane that is angled relative to the longitudinal axis of the spindle, the angle being selected so that the at least one locking member that moves in and out of the slot moves diagonally relative to the longitudinal axis of said spindle. 
     
     
         21 . The surgical tool of  claim 12 , wherein said spindle is further formed so that the distal bore has a circular cross sectional profile.