US 5,993,454 AGranted

Drill attachment for a surgical drill

AssigneeStryker Corporation

InventorPaul T. Longo

Life of this patent

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Abstract

A drill attachment (10) for decreasing the rotational speed/increasing the output torque of a cutting accessory (14) that is attached to a drill such as a surgical drill (10). The drill attachment has an input drive shaft (34) that is coupled to the drive shaft (16) of the drill to rotate in unison with the drill drive shaft. The input drive shaft rotates a set of axially fixed input planet gears (58). The input planet gears rotate a ring gear (66) that is fitted around the input planet gears. The ring gear rotates a set of axially fixed output planet gears (70). The planet gears rotate an output drive shaft (84). By the selective dimensioning of the drive shaft and gears the output speed/torque can be reduced and increased as desired.

Claims22

Dependent claims

A drill attachment comprising:

a housing having first and second opposed ends, said housing first end having a means for releasably coupling said housing to a drill;
an input drive shaft rotatably coupled to said housing, said input drive shaft having a first end located adjacent said housing first end and a second end distal from said first end, said first end having a coupling mechanism for mating said input drive shaft to a drill shaft, said second end shaped to form an input sun gear;
a plurality of input planet gears that are rotatably mounted to a plurality of first axial pins that are fixedly fitted to said housing, said input planet gears being positioned to engage said input sun gear so as to rotate with the rotation of said input drive shaft;
a ring gear rotatably disposed in said housing and fitted around said input planet gears, said ring gear having an outer surface and an inner surface, said inner surface being formed with teeth for engaging said input planet gears so that said ring gear rotates with the rotation of said input planet gears;
a plurality of output planet gears that are rotatably mounted to a plurality of second axial pins that are fixedly fitted to said housing, said output planet gears being positioned to engage said teeth of said ring gear so that said output planet gears rotate with said rotation of said ring gear;
an output drive shaft rotatably coupled to said housing, said output drive shaft having first and second spaced apart ends, said output drive shaft first end having an output sun gear positioned to engage said output planet gears so that said output drive shaft rotates with the rotation of said output planet gears, said output drive shaft second end being located adjacent said housing second end;
and
a coupling assembly fitted to said output drive shaft second end for releasably coupling a cutting accessory to said output drive shaft so that the cutting accessory rotates in unison with said output drive shaft.

5 more elements

A surgical drill assembly comprising:

a surgical drill, said surgical drill including:
a handpiece;
a motor disposed in said handpiece;
and a drill shaft rotatably mounted in said handpiece and connected to said motor to rotate with actuation of said motor;
and
a drill attachment, said drill attachment including
a housing that is coupled to said handpiece of said surgical drill and locked against rotation relative to said surgical drill;
an input drive shaft rotatably mounted in said housing, said input drive shaft having a first end located adjacent said housing first end and a second end distal from said first end, said first end being coupled to said drill shaft, said second end having a head shaped to form an input sun gear;
a plurality of input planet gears that are rotatably mounted to a plurality of first pins that are fixedly fitted to said housing, said input planet gears being positioned to engage said input sun gear so as to rotate with the rotation of said input drive shaft;
a ring gear rotatably disposed in said housing and fitted around said input planet gears, said ring gear having an outer surface and an inner surface, said inner surface being formed with teeth for engaging said input planet gears so that said ring gear rotates with the rotation of said input planet gears;
a plurality of output planet gears that are rotatably mounted to a plurality of second pins that are fixedly fitted to said housing, said input planet gears being positioned to engage said teeth of said ring gear so that said output planet gears rotate with said rotation of said ring gear;
an output drive shaft rotatably coupled to said housing, said output drive shaft having first and second spaced apart ends, said output drive shaft first end having an output sun gear positioned to engage said output planet gears so that said output drive shaft rotates with the rotation of said output planet gears, said output drive shaft second end being located adjacent said housing second end;
and
a coupling assembly coupled to said output drive shaft second end for releasably coupling a cutting accessory to said output drive shaft so that the cutting accessory rotates in unison with said output drive shaft.

11 more elements

A drill accessory for attachment to a surgical drill, said drill accessory including:

a housing have opposed first and second ends, said first end having a means for coupling said housing to a surgical drill;
an input drive shaft rotatably mounted in said housing first end, said input drive shaft having a means for coupling said input drive shaft to a drill shaft integral with the surgical drill and being formed with an input sun gear that is coaxial with said input drive shaft and that is located within said housing;
an output drive shaft rotatably mounted in said housing second end, said output drive shaft being coaxially aligned with said input drive shaft and being formed with an output sun gear that is coaxial with said output drive shaft and that is located adjacent said input sun gear;
a ring gear disposed in said housing, said ring gear having an outer wall that is dimensioned to be spaced away from an adjacent inner wall of said housing so that said ring gear can freely rotate in said housing and an inner wall formed with teeth, said ring gear being positioned to extend around portions of said sun gears that are adjacent each other;
a plurality of input planet gears that are rotatably mounted in said housing to first pins that are fixed to said housing, said input planet gears being positioned to engage said input sun gear and said teeth of said ring gear so that said input planet gears transfer the rotational movement of said input drive shaft to said ring gear;
a plurality of output planet gears that are rotatably mounted in said housing to second pins that are fixed to said housing, said output planet gears being positioned to engage the teeth of said ring gear and said output sun gear so that rotation of said output planet gears transfers the rotational movement of said ring gear to said output drive shaft;
and
a coupling assembly attached to said output drive shaft second end for releasably coupling a cutting accessory to said output drive shaft so that the cutting accessory rotates in unison with said output drive shaft.

5 more elements

Dependencies are inferred from the claim text.

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Abstract

A drill attachment comprising:

a housing having first and second opposed ends, said housing first end having a means for releasably coupling said housing to a drill;
an input drive shaft rotatably coupled to said housing, said input drive shaft having a first end located adjacent said housing first end and a second end distal from said first end, said first end having a coupling mechanism for mating said input drive shaft to a drill shaft, said second end shaped to form an input sun gear;
a plurality of input planet gears that are rotatably mounted to a plurality of first axial pins that are fixedly fitted to said housing, said input planet gears being positioned to engage said input sun gear so as to rotate with the rotation of said input drive shaft;
a ring gear rotatably disposed in said housing and fitted around said input planet gears, said ring gear having an outer surface and an inner surface, said inner surface being formed with teeth for engaging said input planet gears so that said ring gear rotates with the rotation of said input planet gears;
a plurality of output planet gears that are rotatably mounted to a plurality of second axial pins that are fixedly fitted to said housing, said output planet gears being positioned to engage said teeth of said ring gear so that said output planet gears rotate with said rotation of said ring gear;
an output drive shaft rotatably coupled to said housing, said output drive shaft having first and second spaced apart ends, said output drive shaft first end having an output sun gear positioned to engage said output planet gears so that said output drive shaft rotates with the rotation of said output planet gears, said output drive shaft second end being located adjacent said housing second end;
and
a coupling assembly fitted to said output drive shaft second end for releasably coupling a cutting accessory to said output drive shaft so that the cutting accessory rotates in unison with said output drive shaft.

5 more elements