Chuck and blade for powered medical handpiece

A chuck for mounting on and oscillatory driving by a powered medical handpiece for oscillatory driving of blades, including cast cutter blades, said chuck comprising:

• a platform for mounting on and oscillatory driving by a medical handpiece and having an exposed top face;
• clamp means protruding from said platform top face and adjustable up and tightenable down with respect to said platform top face, said clamp means having radially enlarged head means adjustable toward and away from said platform top face for alternatively clamping a blade fixedly with respect to said platform and unclamping said blade from said platform;
• drive means fixed with respect to and upstanding from said platform top face at a location radially offset from said clamp means and moveable through an arc upon oscillatory driving of said chuck by a powered medical handpiece, said upstanding drive means being engageable with a blade for oscillating same in response to oscillatory driving by a medical handpiece;
• guide pin means upstanding from said platform adjacent said head means, for controlling the lateral position of a blade as the latter drops past said head means, said drive means including drive pin means upstanding from said platform adjacent said head means for positive oscillatory driving of a blade, said guide pin means being taller than said drive pin means.

In combination, a powered medical handpiece, including an oscillating driveable chuck, and a blade removeably fixable on said chuck and oscillatingly driveable thereby at low amplitude for cutting hard material such as cast material or bone without harming adjacent soft tissue, said combination comprising:

• a chuck comprising a platform, a holddown screw having enlarged head means and means defining a shank threaded into a central portion of said platform for varying the spacing of said head means above said platform, said screw shank having a diameter less than said head means and extending from said head means into said platform;
• a plate-like blade having cutting means at least a front edge thereof for positioning in front of said chuck, mounting means for fixed mounting of said blade on said chuck and including a holddown opening having a first portion for initially receiving a portion of said screw with said blade in an intermediate position on said chuck, said holddown opening having a second portion communicating with said first portion in a manner to allow said blade to slide laterally along said platform with said screw shank shifting from said first portion to said second portion of said holddown opening, said second portion of said holddown opening having anti-rotation lock means engageable between said head means and platform for resisting unintended unthreading of said holddown screw from said platform.

A chuck for mounting on and oscillatory driving by a powered medical handpiece for oscillatory driving of blades, including cast cutter blades, said chuck comprising:

• a platform for mounting on and oscillatory driving by a medical handpiece;
• threaded clamp means for continuously maintaining threaded engagement with said platform throughout installation and removal of a blade with respect to said platform, said clamp means being captively located on and threaded with respect to said platform, said clamp means compressing a radially enlarged head means threadably adjustable toward said platform for clamping a blade fixedly to said platform and threadedly adjustable away from said platform for unclamping a blade from said platform;
• keeper means capturing said clamp means for limiting spacing of said head means from said platform between a captive tight position clamping a blade to said platform and a captive loose position allowing sliding of a blade along said platform laterally out of range of clamping engagement by said head means despite continued engagement by said clamp means with said platform;
• drive means fixed with respect to and upstanding from a top face of said platform at a location radially offset from said clamp means and moveable through an arc upon oscillatory driving of said chuck by a powered medical handpiece, said upstanding drive means being engageable with a blade for oscillating same in response to oscillatory driving by a medical handpiece.