Surgical drill with curved burr attachment and method

In combination, an adapter and a bendable burr attachment removably coupled to said adapter,

• said burr attachment having a proximal end and distal end and including:
• a tube,
• a wire shaft disposed in said tube and extending beyond the distal end thereof,
• a cutter mounted on the distal end of said wire shaft and extending beyond said tube,
• a helically wound coil wire surrounding said wire shaft fitted between said wire shaft and said tube assuring that the burr attachment does not kink when bent and the outer diameter of said coil wire bearing against the inner surface of said tube and the inner diameter of said coil spring bearing against the outer diameter of said wire shaft, each of the coils of the coil wire touching said inner surface of said tube and the outer diameter of said wire shaft for minimizing the heat transfer from said wire shaft to said tube,
• a proximal end support attached to a proximal end of said wire shaft and coupled to said adapter and affixed thereto so as to rotate therewith, said proximal end support including;
• a generally cylindrical shaped main body;
• a reduced diameter portion on one end thereof;
• an annular groove formed intermediate the ends thereof;
• an adapter coupling feature such that the proximal end support is coupled to the adapter at a predetermined orientation position, the adapter coupling feature including an asymmetrical tapered tip portion for entering a passage formed in said adapter, said tapered tip having only one orientation position that allows entrance into said passage;
• a distal end support coupled to said proximal end support such that said proximal end support rotates independent of said distal end support;
• said adapter including a main housing having a central axis and defining a cavity having an inlet for receiving the proximal end of said burr attachment and operatively connected to said wire shaft for rotating said cutter;
• a sleeve mounted over said main housing defining a grip adapted to be held by a surgeon for use in a medical procedure;
• a spindle mounted in said cavity being in coincidence with the axis of said housing and coupled to a motor to impart rotational motion thereto;
• said burr attachment having a dimensional profile on the proximal end that matches a complementary dimensional profile on the inlet to said cavity for receiving said burr attachment in only a predetermined orientation;
• a coupling element for mating said burr attachment to said spindle, said coupling element including a detent formed on said proximal end support and including a ball supported in said adapter for engaging the detent to couple said burr attachment and said spindle for powering said cutter,
• a cam having a tapered edge formed on an inner diameter thereof, said cam cooperating with the ball for forcing said ball into the detent formed on said proximal end support to couple the burr attachment to said spindle;
• and
• a spring disposed between a shoulder extending from an outer surface of the spindle and a proximal end of the cam,
• wherein said spring biases said cam toward a distal end of the burr attachment.

A curved burr attachment including a burr attachment and an adapter rotatably driven by a motor wherein said burr attachment is coupled to said adapter for rotational motion by the insertion of said burr attachment into said adapter and removable from said adapter by pulling said burr attachment to decouple and remove the burr attachment from said adapter,

• said burr attachment including a tube, a wire shaft supported in said tube having a proximal end support and a distal end support, a cutter attached to said wire shaft, a helically wound coil wire surrounding said shaft and disposed between said wire shaft and said tube, wherein the outer periphery of each of said coils of said coil wire touch the inner surface of said tube and the inner periphery of each of said coils of said coil wire touch the outer surface of said wire shaft,
• said adapter including a main housing defining a cavity,
• a spindle adapted to be driven by a drill motor disposed in said cavity and having a partial bore formed on one end thereof,
• said proximal end support being affixed to a proximate end of said wire shaft and coupled to said adapter and affixed to rotate therewith, said proximal end support being disposed in said partial bore of said spindle, said proximal end support including;
• a generally cylindrical shaped main body;
• a reduced diameter portion on one end thereof;
• an adapter coupling feature such that the proximal end support is coupled to the adapter at a predetermined orientation position, said coupling feature including an annular groove formed on said proximal end support, said coupling feature also include an asymmetrical tapered tip portion for entering a passage from in said adapter and being designed such that said tapered tip portion has one orientation position that allows entrance into the passage;
• said distal end support coupled to said proximal end support such that said proximal end support rotates independently of said distal end support,
• a sleeve-shaped cam having tapered inner surface at its forward end and biased on one end by a spring,
• balls freely disposed in holes formed in said spindle and between the inner surface of said main housing,
• said proximal end support having a flat portion and said annular groove formed adjacent thereto such that movement of said burr attachment into said cavity causes said balls to engage said sleeve-shaped cam and urge it rearwardly to compress said spring,
• when the force of said spring reaches a predetermined value it will force said sleeve-like cam toward the distal end so that said tapered inner surface engages said balls to radially force said balls into said annular groove of said proximal end support to couple said spindle thereto to rotate said wire shaft and automatically lock said burr attachment in place in said adapter.