Surgical burs with localized auxiliary flutes

Patent metadata

Field	Value
Publication number	US-10786266-B2
Application number	US-201815966778-A
Country	US
Kind code	B2
Filing date	Apr 30, 2018
Priority date	Mar 31, 2015
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

A surgical bur including primary flutes and auxiliary flutes. The primary flutes include (i) first clearance surfaces, and (ii) first rake surfaces with first cutting edges. The primary flutes extend from a proximal end of the surgical bur to a distal end of the surgical bur. The auxiliary flutes are localized in central regions or distal regions of the surgical bur. The auxiliary flutes include (i) second clearance surfaces, and (ii) second rake surfaces with second cutting edges. At least one of the auxiliary flutes is located between a pair of adjacent ones of the primary flutes.

First claim

What is claimed is:

1. A surgical bur for use in cutting bone, comprising:
a plurality of primary cutting flutes comprising (i) first clearance surfaces, and (ii) first rake surfaces having first bone cutting edges, wherein the plurality of primary cutting flutes and the first bone cutting edges extend from a proximal end of the surgical bur to a distal end of the surgical bur;
a plurality of auxiliary cutting flutes localized in distal regions of the surgical bur, wherein the plurality of auxiliary cutting flutes comprise (i) second clearance surfaces, and (ii) second rake surfaces having second bone cutting edges, wherein at least one of the plurality of auxiliary cutting flutes is located between a pair of adjacent ones of the plurality of primary cutting flutes; and
wherein the first bone cutting edges formed by the first rake surfaces and the second bone cutting edges formed by the second rake surfaces are configured to cut the bone;
wherein a primary relief surface is between each primary cutting flute and each auxiliary cutting flute;
wherein each first bone cutting edge defines a first outermost point on a circle that is perpendicular to an axis of rotation of the surgical bur;
wherein each primary relief surface has a positive relief angle that does not track the circle extending through the first outermost points to provide less surface contact and drag.

2. The surgical bur of claim 1 , wherein the second clearance surfaces or the second rake surfaces are semi-circular shaped.

3. The surgical bur of claim 1 , wherein the plurality of auxiliary cutting flutes have positive or negative radial rake angles.

4. The surgical bur of claim 1 , wherein the plurality of auxiliary cutting flutes have positive or negative taper angles.

5. The surgical bur of claim 1 , wherein the plurality of auxiliary cutting flutes have different depths.

6. The surgical bur of claim 1 , wherein the plurality of auxiliary cutting flutes have different inside flute angles.

7. The surgical bur of claim 1 , wherein the plurality of auxiliary cutting flutes have positive or negative axial rake angles.

8. The surgical bur of claim 1 , wherein the plurality of auxiliary cutting flutes have left-hand or right-hand flute axial angles.

9. The surgical bur of claim 1 , wherein two or more of the plurality of auxiliary cutting flutes are located between the pair of adjacent ones of the plurality of primary cutting flutes.

10. The surgical bur of claim 1 , wherein:
the two or more of the plurality of auxiliary cutting flutes comprise a first auxiliary cutting flute and a second auxiliary cutting flute; and
the first auxiliary cutting flute is (i) between one of the plurality of primary cutting flutes and the second auxiliary cutting flute, or (i) distal to the second auxiliary cutting flute.

11. The surgical bur of claim 1 , wherein the second clearance surfaces and the second rake surfaces are planar surfaces that form semi-circular shaped second clearance surfaces and semi-circular shaped second rake surfaces.

12. The surgical bur of claim 1 , wherein:
the plurality of auxiliary cutting flutes comprise (i) inside flute angles, (ii) negative radial rake angles, and (iii) depths of less than a predetermined depth; and
the inside flute angles are right angles.

13. The surgical but of claim 1 , wherein each of the plurality of auxiliary cutting flutes are cut-out sections of a corresponding one of the plurality of primary cutting flutes.

14. A surgical bur for use in cutting bone, comprising:
a plurality of primary cutting flutes comprising (i) first clearance surfaces, and (ii) first rake surfaces having first bone cutting edges, wherein the plurality of primary cutting flutes and the first bone cutting edges extend from a proximal end of the surgical bur to a distal end of the surgical bur;
a plurality of auxiliary cutting flutes localized in distal regions of the surgical bur, wherein the plurality of auxiliary cutting flutes comprise (i) second clearance surfaces, and (ii) second rake surfaces having second bone cutting edges, wherein at least one of the plurality of auxiliary cutting flutes is located between a pair of adjacent ones of the plurality of primary cutting flutes; and
wherein the first bone cutting edges formed by the first rake surfaces and the second bone cutting edges formed by the second rake surfaces are configured to cut the bone;
wherein the plurality of auxiliary cutting flutes are located relative to an equator such that (i) first halves of the auxiliary cutting flutes are distal to the equator, and (ii) second halves of the auxiliary cutting flutes are proximal to the equator.

15. A surgical bur for use in cutting bone, comprising:
an equator that is a planar portion of the surgical bur that is perpendicular to an axis-of-rotation and where a diameter of the surgical bur is at a maximum;
a plurality of primary cutting flutes comprising (i) first clearance surfaces, and (ii) first rake surfaces having first bone cutting edges;
a plurality of auxiliary cutting flutes comprising (i) second clearance surfaces, and (ii) second rake surfaces having second bone cutting edges, wherein at least one of the plurality of auxiliary cutting flutes is located between a pair of adjacent ones of the plurality of primary cutting flutes; and
wherein the plurality of auxiliary cutting flutes extend distally from the equator and do not extend fully from a proximal end of the surgical bur to a distal end of the surgical bur;
wherein the first bone cutting edges formed by the first rake surfaces and the second bone cutting edges formed by the second rake surfaces are configured to cut the bone;
wherein each first bone cutting edge defines a first outermost point on a first outer circle that is perpendicular to an axis of rotation of the surgical bur;
wherein each second bone cutting edge defines a second outermost point on a second inner circle that is perpendicular to an axis of rotation of the surgical bur;
wherein the first outer circle is larger than the second inner circle and the second inner circle is inside the first outer circle.

16. The surgical bur of claim 15 , wherein the plurality of auxiliary cutting flutes are localized in distal regions of the surgical bur.

17. The surgical bur of claim 15 , wherein the plurality of auxiliary cutting flutes are distal to the equator.

18. A surgical bur for use in cutting bone, comprising:
a plurality of primary cutting flutes comprising (i) first clearance surfaces, and (ii) first rake surfaces having first bone cutting edges, wherein at least one of the plurality of primary cutting flutes having at least one first bone cutting edge extend from a proximal end of the surgical bur to a distal end of the surgical bur;
a plurality of auxiliary cutting flutes comprising (i) second planar clearance surfaces, and (ii) second planar rake surfaces having second bone cutting edges, wherein each of the plurality of auxiliary cutting flutes is located between a pair of adjacent ones of the plurality of primary cutting flutes, wherein at least one of the auxiliary cutting flutes extends to the distal end of the surgical bur; and
wherein the plurality of auxiliary cutting flutes do not extend fully from the proximal end of the surgical bur to the distal end of the surgical bur;
wherein the first bone cutting edges formed by the first rake surfaces and the second bone cutting edges formed by the second rake surfaces are configured to cut the bone;
wherein each auxiliary cutting flute includes a transition region between ea

Assignees

• Medtronic Xomed Inc

Inventors

• Kulas John W
• Stearns Donald E

Classifications

• B23C5/1009

  Ball nose end mills · CPC title

• A61B17/1615 Primary

  Drill bits, i.e. rotating tools extending from a handpiece to contact the worked material · CPC title

• A61B17/1695 Primary

  Trepans or craniotomes, i.e. specially adapted for drilling thin bones such as the skull · CPC title

• A61B17/1617 Primary

  with mobile or detachable parts · CPC title

• A61B2017/00544

  pneumatically · CPC title