Medical/surgical powered handpiece for rotating the shaft of a accessory, the handpiece having a coupling assembly that facilitates the fine or coarse adjustment of the extension of the accessory shaft

A surgical cutting accessory, said surgical cutting accessory including:

• an elongated shaft having opposed proximal and distal ends;
• a tissue working member for application to a surgical site on the distal end of said shaft;
• and
• a plurality of retention features on said shaft, each said retention feature shaped to cooperate with a locking element of a surgical handpiece so that the locking element is so engaged, the locking element holds the shaft to the handpiece, said retention features arranged in plural columns that extend forward from the proximal end of said shaft, each column including a plurality of linearly aligned retention features, wherein said retention features are further arranged so that a first said retention feature in a first column of retention features is longitudinally spaced from an adjacent said retention feature in an adjacent second column of retention features.

A surgical handpiece comprising:

• a shell:
• a motor disposed in said shell, said motor including:
• a rotor with a magnet rotatably mounted in said shell;
• a lamination stack disposed around said stack formed from magnetizable material;
• and
• a winding assembly disposed between said lamination stack and said rotor, said winding assembly composed of a plurality of windings, each said winding being formed from a coil of wire, the wire having a rectangular cross sectional profile and being would so that said coil has side sections with void space therebetween, said windings being arranged so the side sections of a each said winding is disposed with the void spaces on either side of the said winding.