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US 6,000,940 AGranted
Surgical bur shank and locking collet mechanism
OwnerRick A. Buss, Shaher Ahmad +1inventors
InventorsRick A. Buss, Shaher Ahmad, Michael F. Wei
Life of this patent
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Abstract
A collet for holding a rotatable tool such as a bur or drill bit having a stepped shaft including a drive shaft having a stepped internal diameter mating with the external diameter of the bur or drill shaft, a plurality of hardened balls mounted in openings in the sleeve, a locking sleeve having a tapered surface movable with the force of a spring against the balls to force the balls against the shaft to lock the shaft in the sleeve. A rotatable locking collar is movable to release the spring force to release the shaft for removal and replacement of the tool.
Claims20
A collet assembly for securely holding a rotatable tool having a cylindrical shaft with a reduced diameter at its proximal end comprising:
- a drive shaft including a cylindrical recess in a wall of the distal end thereof for receiving tool shaft, the internal diameter of the cylindrical recess in said drive shaft being reduced at its proximal end over a portion of the length of said drive shaft, said drive shaft having a plurality of openings in the portion of the drive shaft defining said cylindrical recess;
- a plurality of hardened balls positioned in said openings;
- said balls being slightly larger than the wall thickness of said drive shaft;
- said openings in said drive shaft wall being located in the reduced internal diameter portion of said drive shaft cylindrical recess;
- means rotatably driving said drive shaft;
- locking means securing said tool shaft in said drive shaft, said locking means comprising a locking sleeve coaxially outward of said drive shaft having an internal tapered surface and a flange;
- resilient means urging said locking sleeve toward said hardened balls to force said balls against the reduced diameter distal end of said tool shaft;
- and
- operator-operated means for releasing said locking means to permit insertion and removal of said tool.
6 more elements
A collet assembly for securely holding a rotatable tool having a shaft with a reduced diameter at its proximal end comprising:
- a drive shaft including a cylindrical recess in its distal end for receiving said tool shaft;
- means rotatably driving said drive shaft;
- a housing enclosing said drive shaft;
- a locking sleeve coaxially outward of said drive shaft;
- securing means operatively connected to said locking sleeve for securing a tool shaft in said drive shaft;
- the internal diameter of said drive shaft recess over a portion of its length at the proximal end of said sleeve being significantly less than its diameter at its distal end;
- said securing means being located in the reduced diameter portion of said drive shaft recess;
- resilient means urging said sleeve in a direction to cause said securing means to secure said tool shaft in said drive shaft in the region of said significantly less diameter of said drive shaft recess;
- a rotatable locking collar;
- and
- means interposed between said locking collar and said locking sleeve for moving said securing means to a securing position when said locking collar is rotated in a first direction and for moving said securing means in a releasing direction when said locking collar is rotated in a second direction;
- whereby said collet assembly will not lock a tool shaft which does not include a reduced diameter proximal end.
9 more elements
A collet for securely holding a rotatable tool having a shaft comprising:
- a drive shaft for receiving said tool shaft having a plurality of spaced openings;
- a plurality of hardened balls in said openings, said balls being slightly larger in diameter than the wall thickness of said drive shaft;
- means rotatably driving said drive shaft;
- a housing enclosing said drive shaft;
- a locking sleeve coaxially outward of said drive shaft having an internal tapered surface;
- a first spring urging said locking sleeve toward said hardened balls such that said tapered surface forces said balls against said tool shaft;
- a second spring urging said locking sleeve in the opposite direction from the force of said first spring;
- a rotatable locking collar coaxially outward of said locking sleeve;
- and
- means interposed between said locking collar and said locking sleeve for translating said locking sleeve against said hardened balls when said locking collar is rotated in a first direction and for translating said locking sleeve away from said hardened balls when said locking collar is rotated in the opposite direction.
7 more elements
A collet for securely holding a rotatable tool having a shaft, said shaft having a reduced diameter at its proximal end comprising:
- a drive shaft for receiving said tool shaft, said drive shaft having a reduced diameter at its proximal end and having a plurality of spaced openings;
- a plurality of hardened balls carried in said openings, said balls being slightly larger in diameter than the wall thickness of said drive shaft;
- a housing enclosing said drive shaft and a bearing in said housing at the distal end thereof;
- means rotatably driving said drive shaft to turn said shaft;
- a locking sleeve coaxially outward of said drive shaft having an internal tapered surface and an external flange;
- a first spring urging said locking sleeve toward said hardened balls such that said tapered surface forces said balls against the proximal end of said tool shaft;
- a helical groove in said housing;
- a plurality of balls in said helical groove;
- a locking collar coaxially outward of said balls;
- a locking ring in contact with said balls and a second spring urging said locking ring toward said external flange;
- whereby rotation of said locking collar in one direction causes said balls to be moved axially in said groove and permitting said first spring to force said tapered surface against said hardened balls and said hardened balls against said tool shaft to firmly secure said tool shaft in said drive shaft and rotation of said locking collar in the opposite direction causes said balls to be moved in the opposite direction under the force of said second spring to force the tapered surface away from said hardened balls and releasing said tool shaft.
8 more elements
For use with a collet including a housing, a drive shaft with a plurality of openings near its proximal end, a plurality of balls in said openings, said balls being slightly larger in diameter than the wall thickness of said drive shaft and a bearing in said housing supporting said drive shaft, said drive shaft having an internal axial opening whose diameter is smaller at its proximal end than at its distal end;
- a rotatable surgical tool for performing a surgical procedure comprising a shaft having a smaller diameter proximal end proximal of said bearing and secured by clamping said balls against said proximal end;
- a larger diameter intermediate shaft portion;
- and a rotatable surgical instrument at the distal end thereof.
A surgical tool for use with a source of rotation including a drive shaft with a recess therein of two different diameters comprising:
- a shaft having a proximal end, a distal end, and an intermediate shaft portion having a predetermined diameter;
- said distal end having a surgical head for providing a surgical procedure upon rotation of said shaft;
- said proximal end being of different diameter from said intermediate shaft portion;
- said proximal end having a predetermined length to correspond to the depth of the lesser of the two diameters of a mating drive shaft;
- whereby the securing of said tool for rotatable operation employs the securing of said different diameter proximal end within said drive shaft recess shaft portion.
2 more elements
A collet for securely holding a rotatable tool having a shaft with a reduced diameter at its proximal end comprising:
- a drive shaft for receiving said tool shaft, the internal diameter of said drive shaft being reduced at its proximal end over a portion of its length;
- means rotatably driving said drive shaft;
- a housing enclosing said drive shaft;
- means securing said tool shaft in said drive shaft including resilient means;
- a rotatable locking collar;
- and
- means interposed between said locking collar and said securing means for moving said securing means to a securing position when said locking collar is rotated in a first direction and for moving said securing means in a releasing direction when said locking collar is rotated in a second direction;
- wherein said drive shaft has a plurality of openings, a plurality of hardened balls are positioned in said openings, said balls being slightly larger in diameter than the wall thickness of said drive shaft;
- said securing means comprises a locking sleeve coaxially outward of said drive shaft having an internal tapered surface and a flange, and
- said resilient means urges said locking sleeve in a direction to force said balls against said shaft;
- and
- wherein a second resilient means urges said locking sleeve in the opposite direction from said first resilient means when said locking collar is rotated in said second direction.
9 more elements
A collet for securely holding a rotatable tool having a shaft with a reduced diameter at its proximal end comprising:
- a drive shaft for receiving said tool shaft, the internal diameter of said drive shaft being reduced at its proximal end over a portion of its length;
- means rotatably driving said drive shaft;
- a housing enclosing said drive shaft;
- means securing said tool shaft in said drive shaft including resilient means;
- a rotatable locking collar;
- and
- means interposed between said locking collar and said securing means for moving said securing means to a securing position when said locking collar is rotated in a first direction and for moving said securing means in a releasing direction when said locking collar is rotated in a second direction;
- wherein said drive shaft has a plurality of openings, a plurality of hardened balls are positioned in said openings, said balls being slightly larger in diameter than the wall thickness of said drive shaft;
- said securing means comprises a locking sleeve coaxially outward of said drive shaft having an internal tapered surface and a flange, and
- said resilient means urges said locking sleeve in a direction to force said balls against said shaft;
- and
- wherein said means interposed between said locking collar and said locking sleeve comprises a helical groove in said housing, a plurality of balls in said helical groove, a locking ring in contact with said balls and a second resilient member urging said locking ring toward said flange.
9 more elements
Dependencies are inferred from the claim text.