Surgical Drill Handpiece with Adjustable Cutting Tool Guard

A surgical tool system, comprising:

• a) a surgical tool handpiece, including,
• a housing,
• a tool mount detachably coupled to the housing and having a socket, and
• drive means for driving a replaceable tool assembly coupled to the socket of the tool mount;
• and
• b) the replaceable tool assembly detachably coupled within the socket, the tool assembly including,
• i) a tool holder body having a proximal portion with a proximal end, a distal portion with a distal end, and defining a longitudinal bore extending between the proximal and distal ends and defining a longitudinal slot extending through all or a portion of a wall of the tool holder body and in communication with the longitudinal bore, the proximal portion adapted for engagement with the socket of the tool mount, and the bore defining a bore axis;
• ii) a tool shaft having a proximal end and a distal end, the tool shaft extending within the bore and permanently retained relative to the tool holder body, and the tool shaft movable about a tool shaft axis, the proximal end of the tool shaft being driveable by the drive means;
• iii) a medical tool coupled relative to the distal end of the tool shaft, such that movement of the tool shaft results in corresponding movement of the tool, the tool having a length;
• iv) a bearing sleeve retained in the bore and extending around the tool shaft, the shaft extending within and freely rotatable relative to the bearing sleeve;
• and
• v) a tool guard having a proximal end, a distal end and a central portion, the bearing sleeve disposed in an annular space between the tool guard and the tool shaft, the tool guard being a tubular member having a plurality of longitudinally spaced tabs formed in a wall of the tube, the tabs being radially deformable into a plurality of configurations with the bearing sleeve and for retentive engagement with the tool holder body, and the distal end having an opening sized to permit advancement of the tool therethrough, the tool freely movable relative to the tool guard, wherein relative longitudinal translation of the tool guard relative to the holder body longitudinally displaces the distal end of the tool guard relative to the holder body and sets a defined working length of the length of the tool extending beyond the distal end of the tool guard,
• wherein the working length is adapted to be constant while the handpiece drives the tool shaft.

A method of drilling with a surgical handpiece, comprising:

• a) providing a surgical tool system including,
• i) a surgical tool handpiece, and
• ii) at least one replaceable tool assembly detachably coupled relative to a socket of the handpiece, the tool assembly including,
• A) a tool holder body having a proximal portion with a proximal end, a distal portion with a distal end, and defining a longitudinal bore extending between the proximal and distal ends and defining a longitudinal slot extending through all or a portion of a wall of the tool holder body and in communication with the longitudinal bore, the proximal portion adapted for engagement with the socket of the handpiece, and the bore defining a bore axis;
• B) a tool shaft having a proximal end and a distal end, the tool shaft extending within the bore and permanently retained relative to the tool holder body, and the tool shaft movable relative to a tool shaft axis, the proximal end of the tool shaft having structure by which the drill handpiece is adapted to drive movement of to the tool shaft to about the tool shaft axis;
• C) a medical tool coupled relative to the distal end of the tool shaft, such that movement of the tool shaft results in corresponding movement of the tool, the tool having a length;
• D) a bearing sleeve retained in the bore and extending around the tool shaft, the shaft extending within and freely movable relative to the bearing sleeve;
• and
• E) a tubular tool guard having a proximal end, a distal end and a central portion, the bearing sleeve disposed in an annular space between the tool guard and the tool shaft, and the proximal end of the tool guard frictionally coupled relative to bearing sleeve and/or connected to the tool holder body, and the distal end having an opening sized to permit advancement of the tool therethrough, the tool freely movable relative to the tool guard, wherein relative longitudinal translation of the tool guard relative to the holder body longitudinally displaces the distal end of the tool guard relative to the holder body and sets a defined working length of the length of the tool extending beyond the distal end of the tool guard, wherein the working length is adapted to be constant while the handpiece applies the torque to the tool shaft;
• b) longitudinally displacing, without rotation of the tool guard, the tool guard relative to the holder body by a set distance to define an exposed working length of the tool between the distal end of the tool guard and the distal tip of the tool;
• and
• c) applying the tool to tissue within the working length of the tool.

A surgical tool system, comprising:

• a) a surgical tool handpiece, including,
• a housing,
• a tool mount detachably coupled to the housing and having a socket witha projection extending from the socket, and
• drive means for driving a replaceable tool assembly detachably coupled to the socket;
• and
• b) the replaceable tool assembly detachably coupled within the socket, the tool assembly including,
• i) a tool holder body having a proximal portion with a proximal end, a distal portion with a distal end, and defining a longitudinal bore extending between the proximal and distal ends, the proximal portion adapted for engagement with the socket of the tool mount, and the bore defining a bore axis, the tool holder body having an outer surface defining at least one slot to align with and receive the projection extending from the socket;
• ii) a tool shaft having a proximal end and a distal end, the tool shaft extending within the bore and permanently retained relative to the tool holder body, and the tool shaft movable about a tool shaft axis, the proximal end of the tool shaft driveable by the drive means is adapted to move the tool shaft about the tool shaft axis;
• iii) a medical tool coupled relative to the distal end of the tool shaft, such that movement of the tool shaft results in corresponding movement of the tool, the tool having a length;
• iv) a bearing sleeve retained in the bore and extending around the tool shaft, the shaft extending within and freely movable relative to the bearing sleeve;
• and
• v) a tool guard having a proximal end, a distal end and a central portion, the bearing sleeve disposed in an annular space between the tool guard and the tool shaft, the tool guard being a tubular member, the distal end having an opening sized to permit advancement of the tool therethrough, the tool freely movable relative to the tool guard, wherein the handpiece drives the tool shaft, and
• wherein when the tool assembly is coupled within the socket, the projection is received in the slot and limits relative movement between the tool assembly and the handpiece.