Powered surgical handpiece with improved latch mechanism and rotary to oscillating output drive

A surgical cutting apparatus comprising:

• an elongate hollow housing with a proximal end and a distal end;
• a cutter power assembly located at the proximal end of the housing;
• a drive assembly comprising an oscillator assembly including a driver comprising an oscillator shaft member, the oscillator shaft member having a longitudinal axis;
• a chuck assembly coacting with said drive assembly and comprising:
• a chuck having an opening for receiving a surgical tool, an outer face of said chuck having at least two radially spaced open bore apertures, and the chuck having a longitudinal axis;
• an elongate hollow collar having an opening at a first end for receiving said chuck therein, said collar having slots corresponding to said apertures on an inner surface at the first end thereof;
• balls for insertion into said apertures and for receipt in said slots;
• and
• a spring for biasing said collar outwardly,
• wherein applying a force at the distal end of said collar compresses said spring to enable radially outward movement of said balls and insertion of an end of a surgical tool into the opening in the chuck, the surgical tool having a longitudinal axis, and wherein release of said collar locks the surgical tool in said chuck,
• wherein operation of the cutter power assembly provides power to the oscillator assembly so that the oscillator shaft member rotatably oscillates about a longitudinal axis thereof to rotatably oscillate the chuck and the surgical tool fixedly secured to the chuck, and
• wherein the longitudinal axes of the chuck, the oscillator shaft member and the surgical tool are common axes.

A surgical cutting apparatus comprising:

• an elongate hollow housing with a proximal end and a distal end;
• a motor assembly located at the proximal end of the housing, said motor assembly including a motor and a motor output shaft;
• an eccentric output assembly disposed in the housing and comprising:
• a single elongate eccentric shaft having a first shaft portion defining a central longitudinal axis at a first end thereof, said eccentric shaft configured to be rotatably driven at the first end by said motor output shaft of said motor, said eccentric shaft having a second eccentric shaft portion at an opposing second end of said eccentric shaft, the second eccentric shaft portion having a longitudinal projecting axis that is substantially parallel to and spaced from the central longitudinal axis of said first shaft portion, wherein rotation of said eccentric shaft moves said second eccentric shaft portion about an orbital path;
• and
• a transfer member mounted to the second eccentric shaft portion, the transfer member being movable about the orbital path;
• an oscillator assembly located toward the distal end of the housing from the eccentric output assembly comprising:
• an oscillator formed by an oscillator shaft member at a first end and a receiver for receiving the transfer member at a second end, said oscillator shaft member having a longitudinal axis that is parallel to the central longitudinal axis of said first shaft portion of said eccentric shaft;
• and
• a nose cone for receiving said oscillator therein, said nose cone being secured to the distal end of the elongate hollow housing;
• and,
• a chuck assembly located at the distal end of the housing comprising an elongate chuck for mounting at a proximal end to said oscillator assembly, said chuck having an opening at a distal end for receiving a cutting accessory and said chuck having a longitudinal axis,
• wherein operation of said motor rotates said eccentric shaft to move said transfer member about the orbital path so that said oscillator shaft member of said oscillator oscillates about the longitudinal axis thereof by pivotally rotating in a first direction about the longitudinal axis thereof and subsequently pivotally rotating in a second opposing direction about the longitudinal axis thereof, the oscillation of said oscillator shaft member comprising periodically changing between the first and second directions so that said chuck secured thereto rotatably oscillates about the longitudinal axis of said chuck, and an elongate cutting accessory fixedly mounted to the distal end of said chuck and rotatably oscillating with the chuck about a longitudinal axis of the cutting accessory.

A cutting apparatus comprising:

• an elongate hollow housing with a proximal end and a distal end;
• a cutter power assembly located at the proximal end of the housing, said cutter power assembly including a power output shaft;
• an oscillator assembly mounted in the housing comprising an oscillator having a shaft member with a mating projection, said oscillator being oriented toward the distal end of the elongate housing;
• a linking assembly mounted in the housing, said linking assembly linking said power output shaft to said oscillator;
• and
• a chuck assembly comprising:
• a chuck with a mounting element having a pair of prongs at a first proximal end of the chuck for receiving therebetween said mating projection of said shaft member of said oscillator and an opening at a second distal end for receiving a cutting accessory, an outer face of said chuck having equidistant and radially spaced apertures;
• an elongate annular hollow collar having openings at opposing ends thereof, an opening at a first end for receiving said chuck therein, said collar having equidistantly spaced axially oriented slots on an inner surface at the first end thereof, said slots corresponding to said apertures;
• balls for insertion into said apertures and for receipt in said slots;
• and
• a spring for positioning against an inner lip of said collar to bias said collar outwardly to at least enclose or to extend beyond the distal end of said chuck,
• wherein applying a force at the distal end of said collar compresses said spring to enable viewing of said chuck and insertion of an end of a cutting accessory into the opening in the chuck, wherein release of said collar extends the collar distally whereby said balls bear against a surface of said slot so that at least two of said balls move inwardly through at least two respective open ones of said apertures to engage in detents of a locking tab of a cutting accessory to lock the cutting accessory in said chuck.